Ch 10 Impact Analysis 05.09 - GIBB

ESKOM PBMR DPP EIA Version 1.0 / September 2008 Environmental Impact Report

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10 IMPACT ANALYSIS

10.1 Introduction

The significant environmental impacts identified in the Scoping Phase as well as newly identified impacts have been assessed through the various specialist studies. The findings of the impact assessment have been consolidated into Table 10.1 to Table 10.4 below. The impacts have been classified as impacts on the biophysical environment and impacts on the socio-economic environment. The impacts are further classified in terms of the phase of the development in which they are likely to occur namely construction phase (Table 10.1), commissioning phase (Table 10.2 ), operational phase (Table 10.3) or decommissioning phase (Table 10.4). The significance of residual impacts is marked according to the following colour code:

Impact of high significance

Impact of medium significance

Impact of low significance

Impact Unknown

Table 10.5 – 10.8 summarise the results of the impact assessment. During the analysis specialists were required to consider the impact significance before and after mitigation measures are implemented. The mitigation measures are highlighted in chapter 9 and 11 and discussed in depth in the specialist reports. In addition, suggested mitigation measures for identified impacts are provided in the Environmental Management Plan (Appendix AN). Even though some impacts are seen to be of high sig nificance, with specific reference to those involving radiological contamina tion, it must be highlighted that the probability that these impacts will occur is exceptionally low.


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Table 10.1: Detailed assessment of identified impacts for the C onstruction Phase Potential construction phase impacts MITIGATION EXTENT DURATION INTENSITY PROBABILITY SIGNIFICANCE CONSEQUENCE CONFIDENCE

Biophysical impacts

Surface Water

Description: Surface soils are non-cohesive and erosion related to rain events will be a concern. It is likely that such erosion may not produce significant scars in surface soils, but the normal functioning of stormwater management infrastructure could be severely impeded by siltation resulting from surface soil erosion.

Without Local Short-term High Highly Probable Low Low High

(a) Impact 1: Erosion of Surface Soils

With Local Short-term Low Improbable Low Low High

Description: The transport of contaminants via surface water during construction will be a risk. The primary source of contamination will be in maintenance of construction equipment where mechanical workshops and refuelling points will play a significant role.

Without Local Short-term High Highly Probable Low Low High

(b) Impact 2: Contamination of Surface Runoff


Wetlands

Description: All wetland patches within the laydown area (laydown area 1 - second section) would be completely destroyed by its use as a laydown area.

Without Local Permanent Medium Definite Medium Medium High

(a) Impact 1: Loss of Ficinia nodosa wetlands

With Mitigation not possible

Description: Although Ficinia nodosa wetlands do not have a high significance in their own rights, they do play an important role as a buffer area between wetland areas to the south and existing and proposed activities associated with the KNPS itself.

(b) Impact 2: Loss of buffering capacity for adjacent seasonal wetlands

Without Regional Permanent High Highly probable High High Medium


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Potential construction phase impacts MITIGATION EXTENT DURATION INTENSITY PROBABILITY SIGNIFICANCE CONSEQUENCE CONFIDENCE

With Local Permanent Medium Probable Medium Medium Medium

Description: The drying out of wetlands could result in the shortening or elimination of the wet season during the construction period, which would result in a loss of habitat for wetland fauna. An increase in groundwater salinity is another of the impacts associated with dewatering. Although dewatering is a relatively short-term activity, salinisation of surface water systems could be a permanent impact, affecting soil salinity and that wetland plant community structure.

Without Regional Permanent High Highly probable High High High

(c) Impact 3: Impacts associated with dewatering – drying of wetlands and increased groundwater salinity (Seasonal Wetlands)

With Local Short-term Medium to low

Probable Low Low Low

Description: Uncontrolled runoff from stockpiles as well as from freshly disturbed areas is likely to contain large loadings of sediment. Sedimentation could infill shallow wetland habitat and increase disturbed sites prone to invasion by weedy and / or alien vegetation.

Without Regional Permanent High Highly probable High High Medium

(d) Impact 4: Impacts associated with receipt of runoff from disturbed areas (Seasonal wetlands)

With (stormwater management. plan)

Local Short-term Low Probable Low Low Medium

Description: During the construction period these wetlands will be exposed to increased disturbance as a result of pedestrian movement, vehicles utilising access roads, increased levels of windblown litter and other sources of disturbance. Their proximity to the site means they are highly vulnerable to accidental impacts as a result of spills, dumping etc. Increased noise is likely to be another impact, frightening away shyer species and interrupting courtship, mating and / or feeding in and around the wetland edges.

Without Local Medium to Short-term

Medium Highly probable Medium Medium

(e) Impact 5: Impacts associated with physical disturbance and noise from construction and laydown areas (Seasonal Wetlands)

With Local Short-term Medium to low

Probable Low Low

(f) Impact 6: Impacts associated with dewatering – drying of wetlands and increased groundwater salinity (Wetlands P6 and

Description: Both these impacts would be more probable in these wetlands, given their proximity to the construction site. Of the two, intrusion of sea water into the underlying aquifers would have a greater and potentially permanent impact, resulting in die-back of Typha capensis in P7 and its eventual replacement, over time, by the more saline tolerant Phragmites australis. The impact of salinity would be more pronounced on P7, as a result of the construction of a cut-off drain upstream of this wetland, cutting it off from fresher surface water flows.


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Without Local Permanent Medium Highly Probable Medium Medium High P7)

With Local Short-term Low Probable Low Low Low

Description: The impact would most likely affect P7, which lies downstream of some of the construction areas. The wetland in fact lends itself to collection of sediment, which would have negative (but mitigable) impacts in terms of infilling of the wetland depression, increased reed invasion and (in the short-term) more turbid water conditions.

Without Local Permanent Medium Highly Probable Medium Medium Medium

(g) Impact 7: Impacts associated with receipt of runoff from disturbed areas (wetlands P6 and P7)

With Local Short-term Low Probable Low Low Medium

Description: This impact would be less significant in the case of these two wetlands that in the case of the wetland mosaic south of the construction site. This is because the wetlands are small and already disturbed, at least in the case of P7, by human activity close at hand as a result of its proximity to the existing training centre.

Without Local Short-term Medium Highly Probable Low Low High

(h) Impact 8: Impacts associated with physical disturbance and noise from construction and laydown areas (Wetlands P6 and P7)

With Local Short-term Low Probable Low Low High

Description: A number of impacts are associated with this activity, such as, removal of Phragmites australis, disturbance of the river bed and release of sediments into the river downstream, disturbance of the river banks and potential erosion of the bank, etc.

Without Local Permanent High Highly probable High High High

(i) Impact 9: Impacts associated with the construction and once off use of a causeway over the Modder River

With Local Short-term Medium Probable Low Low High

Description: During construction, an increase in disturbance in the vicinity of P6 is possible, including runoff of construction material, excavated spoil and noise.

Without Local Medium to Permanent

Medium Highly probable Medium Medium High

(j) Impact 10: Impacts to P6 associated with the construction of a 132 kV sub-transmission line


(k) Impact 11: Impacts to P6 associated with the construction of a pipe line

Description: The pipeline is not expected to pose any substantial threat to existing wetlands. Construction associated impacts could include stockpiling excavated spoil on or near to existing wetlands, or passage of dewatering water into wetlands.


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Without Local Medium to

Permanent Low Possible Low Low Medium

With Local Short-term Low Possible Low Low Medium

Ground Water

Description: Flooding will occur immediately when excavations commence, due to the fact that the natural groundwater level is at approximately 4 mbgl.

Without Local Short-term Medium Definite Low Low High

(a) Impact 1: Flooding of the excavated areas by groundwater


Description: Dewatering the construction areas will result in lowering of the water table. Potential impacts relating to the declining water table include the threat of saline intrusion, drying up of coastal springs and / or seeps, drying up of wetlands and decreased yields of existing production boreholes / well points in the vicinity of the PBMR DPP.


(b) Impact2: Lowering of the water table due to dewatering and pumping of groundwater for construction use

With Local Short-term Low Definite Low Low High

Description: Coastal springs, seeps and wetlands may sustain sensitive ecosystems which may be threatened by the intrusion of saline water.

Without Local Medium-term

Medium Highly Probable Medium Medium High

(c) Impact 3: Intrusion of saline water due to dewatering and pumping of groundwater for construction use.


Description: Coastal springs and seeps in the vicinity of the PBMR DPP site and their associated ecosystems that may be threatened due to dewatering activities.


Medium Probable Medium Medium Medium

(d) Impact 4: Drying up of coastal springs and / or seeps due to dewatering and pumping of groundwater for construction use.

With Local Short-term Low Improbable Low Low Medium


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Description: The survival of wetland ecosystems may be threatened due to dewatering activities.


Medium Probable Medium Medium Medium

(e) Impact 5: Drying up of wetlands due to dewatering and pumping of groundwater for construction use


Description: existing boreholes may experience decreased yields due to the dewatering and pumping activities.

Without Local Short-term Low Improbable Low Low High

(f) Impact 6: Decreased yields of existing production boreholes due to dewatering and pumping of groundwater for construction


Description: Spillages and leaks from sanitation facilities can be kept to a minimum by applying a good housekeeping approach.

Without Local Short-term Low Probable Low Low High

(g) Impact 7: Organic and bacterial contamination of groundwater due to on-site sanitation facilities’ leaks and spillages With Local Short-term Low Improbable Low Low High

Description: Spillages and leaks from fuel, oil and grease storage facilities can be kept to a minimum by applying a good housekeeping approach.


(h) Impact 8: Hydrocarbon contamination of groundwater due to fuel, oil and grease storage facilities’ leaks and spillages


Air Quality

Description: The significance rating for possible impacts to air quality by the proposed PBMR DPP.

Without Local Short-term Low Highly Probable Low Low High

(a) Impact 1: PM10

With Local Short-term Low Highly Probable Low Low High

Description: The significance rating for possible impacts to air quality by the proposed PBMR DPP. (b) Impact 2: PM Deposition

Without Local Short-term Low Highly Probable Low Low High


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Fauna

Description: Natural habitats on construction site will be permanently destroyed. Intensity low because habitats already degraded.

Without Local Permanent Low Definite Low Low High

(a) Impact 1: PBMR DPP - habitat destruction

With Local Permanent Low Definite Low Low High

Description: Dust generated by construction activity will drift into neighbouring habitats and degrade them. Intensity medium because impacts are partial and temporary.

Without Local - but relatively extensive

Short-term Medium Definite Low Low High

(b) Impact 2: PBMR DPP - Dust pollution off site


Description: Some degree of spillage of fuel and other chemicals is inevitable and these will seep into the soil and groundwater. Medium intensity assumes that impacts will be relatively extensive without mitigation.

Without Local Long-term Medium Highly probable Medium Medium Medium

(c) Impact 3: PBMR DPP - Chemical pollution of soil and groundwater

With Local Long-term Low Probable Low Low Low

Description: During construction, groundwater will seep into excavations and will need to be pumped away. This could cause a localised lowering of the water table with knock-on effects on neighbouring wetlands. Level of risk and intensity must be assessed by the relevant groundwater specialist.

(d) Impact 4: PBMR DPP - Lowered water table and attendant degeneration of wetlands off site

This impact was assessed by the Groundwater Special ist – see Impact 2 above. The significance and con sequence ratings of the impact with and without mitigation are low.

(e) Impact 5: PBMR DPP - Disruption of the ecology of local seasonal

Description: If excess groundwater is pumped from excavations into neighbouring seasonal wetlands, it will disrupt the ecology of those wetlands. Intensity high because ecological impacts would be major over several years.


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Without Local Medium-

term High Highly probable High High High wetlands by pumped

groundwater

With Local Medium-term

Low Probable Low Low High

Description: The presence of large numbers of workers within a nature reserve raises the probability that illegal poaching of game will occur. Intensity is unpredictable, but is potentially high if the problem is not controlled.

Without Local Short-term Medium to high

Probable Low Low High

(f) Impact 6: PBMR DPP - Poaching of animals, especially larger animals


Description: Construction activities, especially connected to the disposal of excess groundwater, may extend into the Koeberg harbour area where regionally important seabird breeding colonies are situated. If disturbance to the area is not controlled and correctly timed, there could be impacts on breeding success over several seasons.

Without Regional Short-term High Probable Medium Medium High

(g) Impact 7: PBMR DPP - Disruption of breeding of regionally important bird populations

With Regional Short-term Low Probable Low Low High

Description: A wetland could be partially or completely destroyed by location of a transmission tower. High intensity because of destruction of sensitive habitats.

Without Local Permanent High Probable High High High

(h) Impact 8: 132 kV Transmission line - Destruction of wetland habitat


Description: Construction of the causeway will cause destruction of sensitive wetland habitats, therefore intensity high. Mitigation will reduce impacts from permanent to short-term.

Without Local Permanent High Definite High High High

(i) Impact 9: Modification to Modder River Crossing – Destruction of sensitive wetland habitat


(j) Impact 10: Modification to Modder River Crossing –

Description: There will be destruction of good-quality terrestrial habitat by construction of approaches to the causeway. Mitigation will reduce impacts from permanent to short-term and largely restrict impacts to previously disturbed habitats


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Without Local Permanent Medium Definite High High High Destruction of unspoilt

terrestrial habitat With Local Short-term Low Definite Low Low High

Description: The causeway will change the pattern of water flow, and probable cause damage to downstream substrates and habitats. Intensity medium because impacts will be localised.

Without Local Permanent Medium Highly probable Medium Medium High

(k) Impact 11: Modification to Modder River Crossing – Disturbance of downstream water flow with attendant degradation of wetland habitats


Description: The river and its habitats are an important ecological corridor, especially as it provides safe passage across the N7. The causeway will partially disrupt this corridor, especially for small aquatic animals. Intensity is medium because not all species would be negatively affected and for the most the disruption would be partial.

Without Local Permanent Medium Probable Medium Medium High

(l) Impact 12: Modification to Modder River Crossing – Disruption of faunal movements within the riparian corridor

With Local Short-term Medium Probable Low Low High

Description: Establishment of laydowns in inappropriate areas would result in extensive destruction of pristine habitats. .

Without National Long-term High Definite High High High

(m) Impact 13: Laydown areas - Extensive destruction of pristine natural habitats

With Local Long-term Low Definite Low Low High

Description: Dust generated by construction and transport activities will drift into neighbouring habitats and degrade them. Intensity medium because impacts are partial and temporary.


(n) Impact 14: Laydown areas – Dust pollution off site


Description: Some degree of spillage of fuel and other chemicals is inevitable and these will seep into the soil and groundwater. Medium intensity assumes that impacts will be relatively extensive without mitigation.

(o) Impact 15: Laydown areas – Chemical pollution of soil and groundwater Without Local Long-term Medium Highly probable Medium Medium High


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With Local Long-term Low Highly probable Low Low Medium

Description: Runoff from harden surfaces is likely to carry pollutants, such as oil, into neighbouring low-lying areas. Intensity medium to high because of the possibility of major accidental spillage at storage facilities.


Medium to high

Probable Medium Medium Medium

(p) Impact 16: Lowdown areas – Polluted run-off degrading nearby wetlands


Low Probable Low Low Medium




(q) Impact 17: Laydown areas – Poaching of animals, especially larger mammals

With Local Short-term Low probable Low Low High

Description: Trenches and human activity will cause local disruption of animal movements as well as mortality resulting from animals falling into trenches.


Definite Low Low High

(r) Impact 18: Disruption of animal movements and mortality associated with trenches


Description: Dust generated by construction and transport activities will drift into neighbouring habitats and degrade them. Intensity medium because impacts are partial and temporary.


(s) Impact 19: Dust pollution off site


Description: Some degree of spillage of fuel is inevitable and this will seep into the soil and groundwater. Medium intensity assumes that impacts will be relatively extensive without mitigation.

(t) Impact 20: Chemical pollution of soil and groundwater

Without Local Long-term Medium Highly probable Medium Medium High


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With Local Long-term Low Highly probable Low Low Medium

Description: Runoff from piles of excavated earth is likely to carry excessive amounts of soil into neighbouring low-lying areas, including wetlands, and affect their ecology.


Probable Medium Medium Medium

(u) Impact 21: Polluted runoff degrading nearby wetlands

With Local Short-term Low Probable Low Low Medium




(v) Impact 22: Poaching of animals, especially larger mammals


Description: Inadequate attention to rehabilitation could lead to long-term degradation of habitats, especially by alien vegetation.

Without Local Short-term Medium Probable Medium Medium High

(w) Impact 23: Long-term degradation of habitats.


Flora

Description: Habitat loss will be permanent, but habitat’s already degraded.

Without Local Permanent High Highly Probable High High High

(a) Impact 1: PBMR DPP and adjacent laydown area - Loss of wetland flora and habitat in the south

With Local Permanent Medium Probable Medium Medium High

Description: Habitat loss will be permanent, although habitat is degraded, primary dunes are one of the most sensitive systems at Koeberg.

Without Local Permanent High Highly probable High High Medium

(b) Impact 2: PBMR DPP and adjacent laydown area - Impact on primary dune system

With Local Permanent Low Improbable Low Low High


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Description: Habitat loss at the coast will be compromised and possibly lost.

Without Local Permanent High Highly probable High High High

(c) Impact 3: Alternative laydown Area A – Habitat loss at the coast

With Local Permanent Low Highly probable Low Low High

Description: Habitat loss inland will be permanent

Without Local Permanent Low Highly probable Low Low High

(d) Impact 4: Alternative laydown Area A – Habitat loss inland

With Local Permanent Low Highly probable Low Low High

Description: Permanent loss of rare sand plain fynbos, although somewhat degraded.

Without Local (regional implications)

Permanent Medium Highly probable Medium Medium High

With local mitigation (no biodiversity offset)

Local Permanent Medium to low

Probable Medium to low Medium to low Medium

(e) Impact 5: Triangle laydown are to east of R27 – Loss of Sand Plain Fynbos habitat

With regional mitigation (with biodiversity offset)

Local Permanent Low Highly probable Low Low High

Description: Permanent loss of rare Dune Thicket / Sand Plain fynbos habitat, although fairly degraded.

Without Local (regional implications)

Permanent High Highly probable High High High

(f) Impact 6: Triangle laydown are to east of R27 – Loss of Dune Thicket / Sand plain fynbos habitat.

With Local Permanent Low Probable Low Low Medium


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Description: Towers can potentially compromise and even lead to loss of rare Dune Thicket / Sand Plan Fynbos veld and species locally, this veld is in good condition.

Without Very local

Permanent High Highly Probable High High High

(g) Impact 7: Powerlines – Construction and placing of towers

With Very local

Permanent Low Improbable Low Low High

Description: Widening the causeway will lead to localised losses of rare riverine habitat and possibly several plant species.

Without Very local

Temporary High Highly probable Medium Medium Medium

(h) Impact 8: Modder river causeway – construction and placing of causeway.

With Very local

Permanent Medium Highly probable Medium Medium Medium

Description: Habitat loss will be permanent if no mitigation is implemented, but habitat is degraded.

Without Very local

Temporary High Highly Probable Medium Medium Medium

(i) Impact 9: Water Pipeline – Section 1 (R27)

With Local Temporary Low Probable Low Low High

Description: Possible Habitat loss.

Without Local Permanent High to medium

Highly Probable Medium Medium High

(j) Impact 10: Water Pipeline – Section 2 (power lines and firebreak)

With Local Temporary Low Highly Probable Low Low High


Without Local Permanent High to medium


(k) Impact 11: Water Pipeline – Section 3 (internal road)



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Without Local Permanent Medium to High


(l) Impact 12: Water Pipeline – Section 4 (disturbed veld and dune)



Without Local Permanent Low to medium


(m) Impact 13: Water Pipeline – Section 5 (PBMR Site)


Marine Fauna and Flora

Description: To enable construction, groundwater will be pumped from the proposed development site for a period of 2 years. This water will be released into the sea via the existing outfall pipe used by Koeberg Nuclear Power Station. Due to the high salinity of released water and the dynamic nature of the coastline this impact will be both low in intensity and local in extent

Without Local Short term Low Probable Low Low High

(a) Impact 1: Release of saline groundwater during dewatering of the proposed site

With No mitigation considered necessary

Description: As groundwater discharges from the site of the proposed development into the sea, organic and bacterial contamination of groundwater due to leaks and spillages from on-site sanitation facilities may ultimately result in contamination of the marine environment. Due to the exposed nature of the coastline, contamination is likely to dissipate quickly and is unlikely to have a significant effect on marine organisms


(b) Impact 2: Organic and Bacterial contamination resulting from discharge of contaminated groundwater

With Local Short term Low Improbable Low Low High

(c) Impact 3: Hydrocarbon contamination resulting from discharge of

Description: Discharge of groundwater contaminated with hydrocarbons from fuel, oil and / or grease may result in contamination of the receiving marine environment


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Without Local Medium

Term Low Probable Low Low High contaminated groundwater

With Local Medium Term

Low Improbable Low Low High

Socio-Economic Impacts

Social Environment

Description: Introduction of people dissimilar in demographic profile.

Without Local Short-term Low Definite Low Low High

(a) Impact 1: Introduction of people dissimilar in demographic profile

With Local Short-term Low Highly Probable Low low High

Description: Potential negative increase in antisocial behaviour due to influx of workers and jobseekers into the area.

Without Local Short-term Medium Definite High Medium High

(b) Impact 2: Impact commensurate with inflow of temporary workers

With Local Short-term Medium Highly probable Low Low High

Description: Additional pressure on service delivery.

Without Local Short-term Low to medium

Highly probable Low to medium Low to medium High

(c) Impact 3: Local / Metropolitan Government Impacts

With Local Short-term Low to medium


Description: Increased vehicle movement will contribute to existing serious traffic congestion problems and routine daily movement patterns.

Without Local Short-term Medium Highly probable Medium Medium High

(d) Impact 4: Impact on daily movement patterns

With Local Short-term Medium Highly probable Low to medium Low High


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Description: Potential negative nuclear-related health impacts and other safety risks related to construction projects.


(e) Impact 5: Public Health and safety


Economic Environment

Description: Limited employment opportunities created for local communities.

Without Local to Regional

Short-term Low Improbable Low Low High

(a) Impact 1: Employment Creation


Description: Specific disadvantaged individuals and groups are prevented from equal opportunities (Those with skills that are not in keeping with the requirements of construction firms and the project proponent).

Without Regional Short-term Low to Medium

Improbable Low Low High

(b) Impact 2: Employment Equity and Inequity

With Regional Short-term Low Improbable Low Low High

Description: Impacts that the development may have on property values for homeowners in the immediate area.


(c) Impact 3: Property Values


Description: Reduction in tourism activities and visitors.

Without National Short-term Low Improbable to probable

Low Low to medium High

(e) Impact 4: Tourism



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Land Use

Description: Whether the PBMR DPP is established or not, the development controls will apply to a total area of 7719,4 ha. The application of the 5 km PAZ around the proposed PBMR DPP restricts development on individual erven to the development rights established by the current zoning. Existing property rights are therefore not affected, since zoning rights are not downgraded. It is likely that the lifespan of PBMR DPP will exceed that of the KNPS. Land use controls that prevent the enhancement of land use rights within the 5 km PAZ will therefore continue after KNPS is decommissioned. The impact is acceptable, since it allows land to be used in terms of its existing zoning and does not require that the right to use and develop land be downgraded.

Without Local Long-term Low Definite Low Low High

(a) Impact 1: Effect on existing development rights and use

With No Mitigation Proposed

Description: The ability to achieve enhanced development rights is directly related to the future growth and development of the city within the study area. Enhanced development rights in the form of, e.g, rezoning *such as agricultural to residential) or subdivision is the mechanism by which urban areas expand and change over time. The ability of the land within the 5 km PAZ to acquire enhanced development rights is curtailed by the current development controls applicable to Koeberg, the Atlantis Guide Plan (1981) and the more recent Urban Edge Reports. It is likely that the lifespan of the PBMR DPP will exceed that of KNPS. Land use controls that limit the development of land within the 5 km PAZ will therefore continue after KNPS is decommissioned and the same conditions that affect the ability to achieve enhanced development rights will be applicable. The impact is acceptable, since the City of Cape Town’s future growth is not limited to the area within the 5 km PAZ. Even though the impact is acceptable it is still regarded as a high significance impact due to the fact that the restrictions imposed by the PAZ will never be relaxed, unless the KNPS reaches end of life sometime in the future and the 5 km PAZ is revised

Without Local Long-term High Definite High High High

(b) Impact 2: The ability to achieve enhanced development rights


Description: The 5 km PAZ limits the development and use of land to the existing zoning. 94,6% (7 305,7 ha) of the land within the PAZ boundary is zoned agriculture. Under the current and future development controls for the 5 km PAZ, this land will remain within the agricultural basket of uses. The impact is acceptable in light of the need to conserve agricultural land. The retention of the agricultural zoning prevents the land from being used for urban uses. Where agricultural activities cease, the potential to more the land into a conservation –type use, become available. Even though the impact is acceptable it is still regarded as a high significance impact due to the fact that the restrictions imposed by the PAZ will never be relaxed, unless the KNPS reaches end of life sometime in the future and the 5 km PAZ is revised.

Without Local Long-term Low Definite High High High

(c) Impact 3: Conservation of agricultural land uses



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Heritage

Description: Bulk excavation will cause displacement and destruction of archaeological / palaeontological material.


(a) Impact 1: PBMR DPP Site – Bulk excavation impacts to Pleistocene Palaeontology / archaeology With Local Long-term Low Highly probable Low Low High

Description: Bulk excavation will cause displacement and destruction of Cenozoic palaeontological material and loss of potential scientific data.


(b) Impact 2: PBMR DPP Site – Bulk excavation impacts to Palaeontology (Cenozoic)

With Local Long-term Low Highly probable Low Low High

Description: Given that the area has an established industrial character, additional buildings will have a moderate effect on changes to the cultural environment. .

Without Local Long-term Low Probable Low Low Medium

(c) Impact 3: PBMR DPP site – Impacts of construction on the cultural landscape

With Local Long-term Very low Probable Low Low Medium

Description: Given that impacts will largely be of a surface nature in an area that contains very little cultural material, impacts caused by physical disturbance will be few or none at all.

Without Local Long-term Very low Improbable Low Low Medium

(d) Impact 4: Impacts of construction of the laydown areas on palaeontology / archaeology


Description: Impacts will largely be of a temporary nature in an area that contains no protected built environment, the rural landscape will be subject to temporary loss of vegetation cover and increased industrial ambience during construction.


Very low Improbable Low Low Medium

(e) Impact 5: Impacts of the construction of the laydown areas on the cultural landscape


Low Probable Low Low Medium


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Description: Certain parts of the broader alternative laydown area are known to be sensitive, however, only a small portion of it is known to be “safe” in heritage terms. Disturbance in un-checked areas may damage archaeological sites.

Without Local Long-term Medium Improbable Medium Medium Medium

(f) Impact 6: Impacts of construction of the alternative laydown area on palaeontology / archaeology


Very low Probable Low Low High

Description: Impacts will largely be of a temporary nature in an area dominated by industrial ambience, however, the rehabilitated natural landscape has setting and amenity value which will be temporarily impacted.


Very low Improbable Low Low High

(g) Impact 7: Impacts of the construction of the alternative laydown areas on the cultural landscape

With Local Long-term Low Probable Low Low High

Description: Areas around the Modder river bridge and Port of Saldanha operations are not archaeologically sensitive. There is a very low chance of impacts from land surface disturbance.

Without Local Long-term Very low Improbable Low Low Medium

(h) Impact 8: Impacts of modifications of the R27 on palaeontology / archaeology


Description: The R27 is not a protected linear feature, impacts are not expected.

Without Not applicable

(i) Impact 9: Impacts of modifications of the R27 on the cultural landscape

With Not applicable

Description: Access roads are located mainly within the previously disturbed envelope of land. Impacts caused by surface disturbance of any surviving heritage material are considered to be unlikely.

Without Local Long-term Very low Improbable Low Low High

(j) Impact 10: Impacts of construction of access roads on generally protected heritage

With Local Long-term Very low Probable Low Low High


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Description: Transmission line is to be located mainly within the previously disturbed envelope of land. Impacts caused by surface disturbance of any surviving heritage material are considered to be unlikely.


(k) Impact 11: Impacts of construction of the 132 kV transmission line on generally protected heritage

With Local Long-term Very low Improbable Low Low High

Description: Pipeline is to be located mainly along the firbreak under the powerlines. Impacts caused by surface disturbance of any surviving heritage material are considered to be unlikely.

Without Local Long term Very low Low Low Low High

(l) Impact 12: Impacts of potable water pipeline on generally protected heritage

With Local Long term Very low Low Low Low High

Visual

Description: The 55 m high building plus a 15m stack will be highly visible in the flat and generally featureless landscape of Fynbos and Strandveld. The structure is solid and will mostly be seen against the backdrop of the ocean and sky. It will therefore mostly be viewed as a silhouette from inland.

Without Regional Long-term Low Highly probable Medium Medium High

(a) Impact 1: Visual Impact – PBMR DPP

With Regional Long-term Low Highly probable Medium Medium High

Description: This will be a temporary facility. The area will however, be highly visible from the R27 as a result of it having replaced existing vegetation.

Without Local Short-term Low Highly probable Low Low High

(b) Impact 2: Visual Impact – Laydown Area

With Regional Short-term Low Highly probable Low Low High

Description: The line, although short, adds to the visual complexity at close range of the switchyard and existing transmission lines from the KNPS.

Without Local Long-term Low Highly probable Low Low High

(c) Impact 3: Visual Impact – Transmission Line



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Table 10.2: Detailed assessment of identified impacts for the C ommissioning Phase Potential Commissioning phase impacts MITIGATION EXTENT DURATION INTENSITY PROBABILITY SIGNIFICANCE CONSEQUENCE CONFIDENCE

Biophysical impacts

Seismic Environment

No specific Commissioning impacts were assessed. However, impacts are anticipated to be similar to that of the operational phase.

Surface Water

Description: Newly constructed sites will be characterised with extensive dust / silt build up emanating from recently completed construction activities.

Without Local Short-term High Probable Low Low Medium

(a) Impact 1: Localised flooding due to siltation of surface water management systems


Description: Seasonal wetlands in the area are primarily fed by groundwater, however, it is anticipated that they may also be affected by surface water recharge to some extent. The diversion of stormwater into stormwater management infrastructure may cut-off the supply of surface water to wetlands.

Without Local Long-term High Probable High High Medium

(b) Impact 2: Removal of surface water recharge from wetland systems

With Local Long-term Low Improbable Low Low High

Wetlands

Description: During commissioning, nuclear fuel will be transferred to the site and loaded, and there is some risk of contamination of groundwater and thence of groundwater-fed wetlands.

Without Regional Short-term Low Improbable High High Low

(a) Impact 1: Contamination of wetlands as a result of leakage of nuclear by-products into groundwater

With Regional Long-term High Improbable Low Low Low

(b) Impact 2: Changes in surface flows associated

Description: It is expected that there will be an increase in surface flow velocity as a result of a substantial increase in hardened surfaces.


10-22

Potential Commissioning phase impacts MITIGATION EXTENT DURATION INTENSITY PROBABILITY SIGNIFICANCE CONSEQUENCE CONFIDENCE

Without Regional Permanent Medium to

high Highly probable High High Low with the hardening of

laydown areas

With (assuming pre-approval devel. of stormwater man. plan)

Local Short-term Low to medium


Ground Water

Description: As the commissioning phase represents the ‘start-up’ of the PBMR DPP, unknown problems with the construction of the system will be evident during this phase. Impacts could also result from nuclear fuel being transported to site and being off-loaded on site.

Without Local Short-term High Improbability Medium Medium Medium

(a) Impact 1: Radioactive and toxic contamination of groundwater due to nuclear by-product leaks and spillages With Local Short-term Low Improbability Low Low Medium

Description: Flooding of the reactor has been assessed from a hydrological perspective and the impact on groundwater conditions that exist at the Site, and not based on the impact on the actual constructed works.


(b) Impact 2: Flooding of the reactor by groundwater inflows


Description: In regard to the degradation of the lower raft and retaining walls concrete, as well as soil cement sub-foundation by groundwater, the impact was assessed on the basis of the effect on groundwater quality and not the effect on the actual structures.


(c) Impact 3: Degradation of the lower raft and retaining walls concrete, as well as cement sub-foundations by groundwater With Local Short-term Low Improbable Low Low High



(d) Impact 4: Organic and bacterial contamination of groundwater due to on-site sanitation facilities’ leaks and spillages With Local Short-term Low Improbable Low Low High


10-23




(e) Impact 5: Hydrocarbon contamination of groundwater due to fuel, oil and grease storage facilities’ leaks and spillages


Description: Dewatering the construction areas will result in lowering of the water table. Potential impacts relating to the declining water table include the threat of saline intrusion, drying up of coastal springs and / or seeps, drying up of wetlands and decreased yields of existing production boreholes / wellpoints in the vicinity of the PBMR DPP.


(f) Impact 6: Lowering of the water table due to pumping of groundwater for use




(g) Impact 7: Intrusion of saline water due to pumping of groundwater for use


Description: Coastal springs and seeps may sustain sensitive ecosystems that may be threatened due to dewatering activities.


(h) Impact 8: Drying up of coastal springs and / or seeps due to pumping of groundwater for use


Description: Wetlands may sustain sensitive ecosystems that may be threatened due to dewatering activities.


(i) Impact 9: Drying up of wetlands due to pumping of groundwater for use


Description: existing boreholes may experience decreased yields due to the dewatering and pumping activities. (j) Impact 10: Decreased yields of existing production boreholes due to pumping of groundwater for



10-24


use. With Local Short-term Low Improbable Low Low High

Air Quality

No specific Commissioning impacts were assessed. However, impacts are anticipated to be similar to that of the operational phase.

Flora

No Commissioning impacts were assessed as impacts are anticipated to be restricted to the construction phase.




(a) Impact 1: Organic and Bacterial contamination resulting from discharge of contaminated groundwater


Description: Discharge of groundwater contaminated with hydrocarbons from fuel, oil and / or grease may result in contamination of the receiving marine environment Without Local Medium

Term Low Probable Low Low High

(b) Impact 2: Hydrocarbon contamination resulting from discharge of contaminated groundwater

With Local Medium Term

Low Improbable Low Low High

Description: Discharge of groundwater contaminated with radioactive nucleotides may result in contamination of the receiving marine environmental. Although the intensity of this impact would be high, the probability of its occurrence is low. Without Local Short Term Low Improbable Low Low High

(c) Impact 3: Radioactive contamination resulting from discharge of contaminated groundwater

With Local Short Term Low Improbable Low Low High


10-25



Radiological Safety and Health

No specific Commissioning impacts were assessed. However, impacts are anticipated to be similar to that of the operational phase, due to that fact the study makes no distinction between commissioning and operation due to the loading of the nuclear fuel.

Social Environment



Low Definite Low Low High



Low Highly Probable Low low High




With Local Short-term Low Highly probable Low Low High






Without Local Long-term Low Probable Low Low High




10-26







Description: Access of local communities to employment opportunities .

Without Regional to National

Long-term Medium Highly Probable Medium Medium High


With Regional to National


Description: Access of disadvantaged individuals and groups to equal employment opportunities.

Without Local Medium to long-term

High Highly Probable Medium Medium High


With Local Medium to Long-term

Medium Probable Low Low High


Without Local Long-term Low Improbable Low Low High



Description: Reduction in tourism activities and visitors

Without National Long-term Low Improbable Low Low High


With Regional Long-term Low Improbable Low Low High


10-27


Land Use





Description: The ability to achieve enhanced development rights is directly related to the future growth and development of the city within the study area. Enhanced development rights in the form of, e.g., rezoning *such as agricultural to residential) or subdivision is the mechanism by which urban areas expand and change over time. The ability of the land within the 5 km PAZ to acquire enhanced development rights is curtailed by the current development controls applicable to Koeberg, the Atlantis Guide Plan (1981) and the more recent Urban Edge Reports. It is likely that the lifespan of the PBMR DPP will exceed that of KNPS. Landuse controls that limit the development of land within the 5 km PAZ will therefore continue after KNPS is decommissioned and the same conditions that affect the ability to achieve enhanced development rights will be applicable. The impact is acceptable, since the City of Cape Town’s future growth is not limited to the area within the 5 km PAZ. Even though the impact is acceptable it is still regarded as a high significance impact due to the fact that the restrictions imposed by the PAZ will never be relaxed, unless the KNPS reaches end of life sometime in the future and the 5 km PAZ is revised




Description: The 5 km PAZ limits the development and use of land to the existing zoning. 94,6% (7 305,7 ha) of the land within the PAZ boundary is zoned agriculture. Under the current and future development controls for the 5 km PAZ, this land will remain within the agricultural basket of uses. The impact is acceptable in light of the need to conserve agricultural land. The retention of the agricultural zoning prevents the land from being used for urban uses. Where agricultural activities cease, the potential to more the land into a conservation –type use, become available. Even though the impact is acceptable it is still regarded as a high significance impact due to the fact that the restrictions imposed by the PAZ will never be relaxed, unless the KNPS reaches end of life sometime in the future and the 5 km PAZ is revised





10-28


Heritage

No impacts are anticipated during the commissioning phase

Visual

No specific Commissioning impacts were assessed. However, impacts are anticipated to be similar to that of the operational phase


10-29

Table 10.3: Detailed assessment of identified impacts for the O peration Phase Potential Operation phase impacts MITIGATION EXTENT DURATION INTENSITY PROBABILITY SIGNIFICANCE CONSEQUENCE CONFIDENCE

Biophysical impacts

Oceanography

Description: Mathematical modelling of data collected over seven years indicates that extreme waves are very unlikely to cause flooding at the site of the proposed development.

Without Local Short -term High Improbable Low Low High

(a) Impact 1: Flooding due to extreme waves

With Should the PBMR DPP be built at least 8m above MSL no mitigation measures are considered necessary.

Description: The probability of flooding of the power station due to extreme water levels is considered low as this would require a water level of 6.09 m above MSL and has a recurrence interval of 1 in 106 years.

Without Local Short-term High Improbable Low Low High

(b) Impact 2: Flooding due to extreme water levels


Description: The maximum credible tsunami for the proposed site is predicted to be 4 m above still water level. When combined with the level of highest astronomical tide (i.e. 1.20 m above MSL), a maximum flood level of 5.20 m above MSL could occur. While the probability of such a tide co-occurring with a tsunami is low, a water level of this height will not flood the PBMR DPP if it is built 8 m above MSL.


(c) Impact 3: Flooding due to tsunamis


Description: Under conditions of the maximum credible tsunami, the draw down of water at the site of the proposed development is predicted to reach 4 m below still water level. Should this occur at lowest astronomical tide the extreme low water level could be -4.9 MSL.


(d) Impact 4: Exposure of cooling water intake pipes under tsunami conditions

With Local Short-term High Improbable Low Low High


10-30

Potential Operation phase impacts MITIGATION EXTENT DURATION INTENSITY PROBABILITY SIGNIFICANCE CONSEQUENCE CONFIDENCE

Description: The intake basin is designed in such a way that damage to the breakwaters would not jeopardise the integrity of the intake pipes or the immediate availability of water in the basin. As such no significant threat is posed to the supply of emergency cooling water.


(e) Impact 5: Damage to intake basins

With No mitigation measures required.

Description: As no long-term erosion or accretion of the seabed or surrounding beach has been caused by the building of the intake basin and breakwaters since the construction of KNPS. As such it is highly unlikely that this will occur in the future.

Without Local Short-term Medium Improbable Low Low High

(f) Impact 6: Erosion or accretion of surrounding sediment


Description: As dredging of encroaching sediment has been required only seven times in the last 26 years it is considered unlikely that sedimentation will result in blocking of the entrance to an extent which would impede the inflow of cooling water. Without Local Short-term High Improbable Low Low High

(g) Impact 7: Sedimentation within the intake basin


Description: The threat of blockage of the cooling water system stems predominantly from sand, oil slicks, debris and marine fauna and flora. The structural and operational mitigation measures currently applied to the pumphouse and water intake system to be used by the PBMR are deemed sufficient to minimise the possibility of blockage of intake water. Without Local Short-term High Improbable Low Low High

(h) Impact 8: Blockage of cooling water intake pipes

With No further mitigation measures are required.

Seismic Environment

Description: The steam turbines may have a vibratory movement which could be transferred to the rock on which the PBMR DPP is situated.


(a) Impact 1: Possible vibratory ground motion of the site

With Local Short-term Insignificant Improbable Low Low High


10-31


Description: Short period changes in geology include movement along unknown faults which sometimes cause small earthquakes but larger rock falls in mountainous regions, sand boils or movement of volumes of sediment in the ocean, resulting in seismic shockwaves and aftershocks being transmitted with velocities and amplitudes dependent on the rock media through which they travel.

Without National Long-term High Improbable High High High

(b) Impact 2: Short period tectonic changes in the existing geology, whether from rock fall or other kinds of rock movement within a radius of 230 km With Local Short-term Low Improbable Low Low High

Description: Ridge push from the mid Atlantis Ridge causes the African Plate to be pushed north and north-eastwards causing stress build-up on the African Plate. Therefore stress release causes movement along known or new faults at surface or rock stress release at depth resulting in earthquakes with noticeable to severe ground movement especially in unconsolidated media, resulting in seismic shockwaves and aftershocks being transmitted with velocities and amplitudes dependent on the rock media through which they travel. They are natural phenomena and impossible to predict.

Without National Long-term High Improbable High High High

(c) Impact 3: Movements along any of the known faults or a new fault within a radius of 320 km

With Local Short-term Medium Improbable Low Low High

Description: Faulting or sediment movement causes water displacement resulting in a water wave with substantial larger amplitude that encountered due to for instance spring tide. The sea overflowing the PBMR DPP facility will probable not cause the reactor vessel to be damaged, but could dislodge spent fuel and wash it back to sea with devastating consequences. Tsunami events are natural events, unpredictable and do not constitute a fatal flaw from an environmental or legal perspective if the mitigation measures are followed.

Without Regional Long-term Medium Improbable Medium Medium High

(d) Impact 4: Tsunami Flooding


Description: No collapsing rock formations or high mountains are present within 8 km of the site.

Without Local Long-term Insignificant Improbable Low Low High

(e) Impact 5: Collapsing rock slopes within a radius of 8 km

With Local Short-term Insignificant Improbable Low Low High

Surface Water

(a) Impact 1: Localised flooding due to siltation of surface water

Description: Daily plant operation and impacts relating to poor management and maintenance of surface water infrastructure could cause impacts related to localised flooding.


10-32


Without Local Short-term High Probable Low Low Medium management systems


Description: Seasonal wetlands in the area are primarily fed by groundwater, however, it is anticipated that they may also be affected by surface water recharge to some extent. The diversion of stormwater into stormwater management infrastructure may cut-off the supply of surface water to wetlands.




Wetlands

Description: During operation, a possible contamination of groundwater and thence of groundwater-fed wetlands.

Without Regional Short-term Low Improbable High High Low

(a) Impact 1: Contamination of wetlands as a result of leakage of radioactive material into groundwater

With Regional Long-term High Improbable Low Low Low

Description: It is expected that there will be an increase in surface flow velocity as a result of a substantial increase in hardened surfaces.

Without Local Long-term Low Probable High High Low

(b) Impact 2: Changes in surface flows associated with hardening of portions of the catchment



Description: The impact of abstraction carried out over the long-term, may be higher during periods of drought and, moreover, may result in decreased resilience of affected wetlands to other impacts, over time.

Without Regional Long-term Medium Improbable High High Low

(c) Impact 3: Changes in wetland hydroperiod resulting from groundwater abstraction

With Not Applicable


10-33


Ground Water

Description: The type of radioactivity impacts without mitigation for either the non-nuclear or nuclear accident remains the same, except that the concentrations intensify significantly during nuclear accidents. Further, leaks of nay radioactivity will not directly affect existing groundwater users, but air emissions from the PBMR DPP could be transported inland by prevailing winds and contaminate groundwater by being incorporated into rainfall recharge. The potential impacts during the scenarios remain the same, other that the radioactive and toxic contamination of groundwater due to nuclear by-product leaks and spillages during nuclear accidents. The latter is indicated in brackets below.

Without Regional Short-term

(Medium-term)

High Improbability

(Probable)

Medium

(High)

Medium

(High)

Medium

(a) Impact 1: Radioactive and toxic contamination of groundwater due to nuclear by-product leaks and spillages

With Local Short-term Low Improbability Low Low Medium







(c) Impact 3: Degradation of the lower raft and retaining walls concrete, as well as cement sub-foundations by groundwater With Local Short-term Low Improbable Low Low High



(d) Impact 4: Organic and bacterial contamination of groundwater due to on-site sanitation facilities’ leaks and spillages With Local Short-term Low Improbable Low Low High

(e) Impact 5: Hydrocarbon contamination of groundwater due to fuel,



10-34


Without Local Short-term Low Probable Low Low High oil and grease storage

facilities’ leaks and spillages With Local Short-term Low Improbable Low Low High

Description: Dewatering the construction areas will result in lowering of the water table. Potential impacts relating to the declining water table include the threat of saline intrusion, drying up of coastal springs and / or seeps, drying up of wetlands and decreased yields of existing production boreholes / wellpoints in the vicinity of the PBMR DPP.


(f) Impact 6: Lowering of the water table due to pumping of groundwater for use




(g) Impact 7: Intrusion of saline water due to pumping of groundwater for use


Description: Coastal springs and seeps may sustain sensitive ecosystems that may be threatened due to dewatering activities.


(h) Impact 8: Drying up of coastal springs and / or seeps due to pumping of groundwater for use


Description: Wetlands may sustain sensitive ecosystems that may be threatened due to dewatering activities.


(i) Impact 9: Drying up of wetlands due to pumping of groundwater for use


Description: existing boreholes may experience decreased yields due to the dewatering and pumping activities.


(j) Impact 10: Decreased yields of existing production boreholes due to pumping of groundwater for use.



10-35


Air Quality

Description: The significance rating for possible impacts to air quality by the proposed PBMR DPP.

Without Low Long-term Low Highly probable Low Low High

(a) Impact 1: Radiation Dose

With Not Applicable

Fauna

Description: Collisions of birds with power cables are usually fatal. Because the cables will cross regular flight paths of many birds, the local impact on some species could be intense.

Without Local Long-term Medium Probable Medium Medium Medium

(b) Impact 1: Transmission Power Line – Fatal collisions of birds with the power line

With Local Long-term Low Probable Low Low Medium

Flora

No Operation phase impacts were assessed as impacts are anticipated to be restricted to the construction phase.




(a) Impact 1: Organic and Bacterial contamination resulting from discharge of contaminated groundwater


Description: Discharge of groundwater contaminated with hydrocarbons from fuel, oil and / or grease may result in contamination of the receiving marine environment

(b) Impact 2: Hydrocarbon contamination resulting from discharge of contaminated groundwater

Without Local Medium Term

Low Probable Low Low High


10-36


With Local Medium

Term Low Improbable Low Low High

Description: Discharge of groundwater contaminated with radioactive nucleotides may result in contamination of the receiving marine environmental. Although the intensity of this impact would be high, the probability of its occurrence is low. Without Local Short Term Low Improbable Low Low High

(c) Impact 3: Radioactive contamination resulting from discharge of contaminated groundwater

With Local Short Term Low Improbable Low Low High

Description: The abstraction of additional cooling water is likely to result in additional mortality to both phytoplankton and zooplankton. The rapid rate at which these organisms reproduce, the restriction of the impact to the intake point and the limited conservation importance of the organisms make this impact of low intensity and local extent.


(d) Impact 4: Increased mortality of marine organisms during cooling water abstraction


Description: Marine organisms occurring on the South African West Coast are adapted to a cold water environment. As such they are likely to be sensitive to increases in water temperature. Based on the findings of previous studies, the cumulative increase of cooling water at a temperature of 26.6ºC, is, however, not expected to have nay significant impact on this environment. Under worst-case conditions, the extent of the impact is likely to be within 1 km of the discharge point. Given the above, the impact is accordingly assessed as being of low intensity and local extent.


(e) Impact 5: Impact of mixed Koeberg and PBMR DPP cooling water discharge (26.6ºC) on the marine Environment


Description: Although marine organisms are resilient to variability within their physical environment, changes beyond their tolerance range are fatal. Thus although discharge water of 26.6ºC is unlikely to significantly affect the marine environment, discharge water of 39.9ºC is very likely to have detrimental impacts.


(f) Impact 6: Impact of PBMR DPP cooling water discharge (39.9ºC) on the marine environment.



10-37


Description: A major concern associated with nuclear facilities is the release of radiation emissions into the surrounding environment. The most likely route of contamination of the marine environment from the PBMR DPP is through the release of contaminated cooling water. The risk has been minimised through the design of a ‘double cooling system’ in which a coolant cools the reactor and cold sea water then cools the coolant. As there is no direct contact between the reactor and the coolant and the sea water the probability of this impact occurring is low.


(g) Impact 7: Radiation emissions


Description: Should a large scale nuclear accident occur and the cooling system be breached in such a way that the sea water taken up for cooling purposes comes into contact with the damaged reactor, radioactive contamination of the marine environment may occur. Although the intensity of such an impact would be high, the probability of this occurring is low and the extent is likely to be localised.

Without Local Long-term High Improbable High High High

(h) Impact 8: Radioactive contamination of the marine environment as a result of a nuclear accident

With Local Long-term Medium to high

Improbable High Medium to high High


Radiological Safety and Health

Description: The discharge of radioactive gaseous and liquid emissions from the KNPS and PBMR DPP may result in direct and indirect impacts to humans and the biophysical environment. The safety standards for regulatory practices published in Government Notice R.388 require that radiation emissions during normal Operation from both the KNPS and the PBMR DPP as two individual sources are subject to a dose constraint of 0.25 mSv per year. The AADQ for the KNPS is set at values that will ensure that the dose is below the dose constraint. Similarly, the AADQ for the PBMR DPP will also ensure the dose is below the dose constraint. The combined impact for operational conditions would thus not challenge the dose limit of 1 mSv per year. The cumulative impact from gaseous and liquid discharge to the environment is thus considered to be of low significance.


High Improbable Low Medium High

(a) Impact 1: Cumulative impact of gaseous and liquid emissions on the environment during normal operating conditions

With No additional mitigation considered necessary


10-38


Description: All LILW generated waste at the KNPS and the PBMR DPP will be disposed of at the national radioactive waste disposal facility at Vaalputs. This may result in direct and indirect impacts to humans and the biophysical environment. However, the safety standards for regulatory practices published in Government Notice R.388 require that the dose humans may receive from the disposal of radioactive waste should be below a dose constraint of 0.25 mSv per year, now and in future. The combined impact for waste disposal operations at Vaalputs would thus not challenge the dose limit of 1 mSv per year. The cumulative impact from waste disposal is thus considered to be of low significance.

Without Local Long-term High Improbable Low High High

(b) Impact 2: Cumulative impact on Vaalputs waste disposal site


Description: The KNPS use road transport to ship LILW to Vaalputs for disposal. The transport of the PBMR DPP LILW will be integrated with the KNPS transport system, which might result in an increase in the number of consignments on an annual basis. The impact from the PBMR DPP on the number of Consignments should be low, since the KNPS generates much more LILW and also has to reduce a backlog of historical LILW stored at the KNPS at present. Since the transport of the LILW to Vaalputs is being done according to the IAEA transport regulations, the potential environmental impact is considered to be on a regional scale but of low significance.

Without Regional Short-term High Improbable Low Medium High

(c) Impact 3: Cumulative impact of transport of radioactive waste


Description: Distinction can be made between onsite emergencies (emergencies that do not affect the public) and off-site emergencies (emergencies that have the potential to affect the public). Onsite emergencies can be dealt with effectively within the provisions of the National Nuclear Regulator Act. The management of an off-site emergency is the responsibility of the government authorities under the Disaster Management Act (Act NO. 57 of 2002). The declaration of a “General Emergency” implies a threat to the off-site public, which requires the implementation of off-site protective actions. The cumulative impact from an on-site emergency, albeit at the PBMR DPP or at the KNPS, will be limited to the individual sites. Emergency procedures and the emergency plan prepared as part of the Nuclear Authorisation application will be sufficient to protect people, property and the environment from the adverse effects of radiation exposure. Combined actions will thus not be necessary. The impact from an on-site emergency is thus low and localised.

Without Local Short-term High Improbable Low Medium High

(d) Impact 4Cumulative impact on emergency response planning during normal operating conditions


(e) Impact 5: Cumulative impact on emergency response planning following an accident

Description: In developing and implementing the emergency response plan for the PBMR DPP and the KNPS, cognisance needs to be taken of these characteristics should an accident occur. The cumulative impact on the emergency response planning from an off-site emergency following an accident is that the number of people in a 2 km radius of either one of the two sites that need to be responded to during the early phase of the emergency, will increase, and thus the impact is of low significance.


10-39




Description: A cumulative impact is only possible if Postulating Initiating Event for the two facilities occur concurrently. One has to consider thus the probability and the consequence of such an occurrence. The optimisation of radiation protection principle will also apply for these conditions, to ensure that the potential impacts to members of the public complies with the applicable dose constraint and dose limit published in Government Notice R.388. The impact is of low significance.


(f) Impact 6: Cumulative impact of gaseous emissions on the environment during accident conditions


Social Environment



Low Definite Low Low High



Low Highly Probable Low low High




With Local Short-term Low Highly probable Low Low High








10-40










Without Regional to National



With Regional to National



Without Local Medium to long-term

High Highly Probable Medium Medium High


With Local Medium to Long-term

Medium Probable Low Low High






10-41



Without National Long-term Low Improbable Low Low High


With Regional Long-term Low Improbable Low Low High

Land Use





Description: The ability to achieve enhanced development rights is directly related to the future growth and development of the city within the study area. Enhanced development rights in the form of, e.g, rezoning *such as agricultural to residential) or subdivision is the mechanism by which urban areas expand and change over time. The ability of the land within the 5 km PAZ to acquire enhanced development rights is curtailed by the current development controls applicable to Koeberg, the Atlantis Guide Plan (1981) and the more recent Urban Edge Reports. It is likely that the lifespan of the PBMR DPP will exceed that of KNPS. Landuse controls that limit the development of land within the 5 km PAZ will therefore continue after KNPS is decommissioned and the same conditions that affect the ability to achieve enhanced development rights will be applicable. The impact is acceptable, since the City of Cape Town’s future growth is not limited to the area within the 5 km PAZ. Even though the impact is acceptable it is still regarded as a high significance impact due to the fact that the restrictions imposed by the PAZ will never be relaxed, unless the KNPS reaches end of life sometime in the future and the 5 km PAZ is revised





10-42






Heritage

No impacts are anticipated during the operation phase

Visual

Description: The 55 m high building plus a 15m stack will be highly visible in the flat and generally featureless landscape of Fynbos and Strandveld. The structure is solid and will mostly be seen against the backdrop of the ocean and sky. It will therefore mostly be viewed as a silhouette from inland.

Without Regional Long-term Low Highly probable Medium Medium High

(a) Impact 1: Visual Impact – PBMR DPP

With Regional Long-term Low Highly probable Medium Medium High

Description: The line, although short, adds to the visual complexity at close range of the switchyard and existing transmission lines from the KNPS.

Without Local Long-term Low Highly probable Low Low High

(c) Impact 2: Visual Impact – Transmission Line



10-43

Table 10.4: Detailed assessment of identified impacts for the D e-commissioning Phase Potential de-commissioning phase impacts

MITIGATION EXTENT DURATION INTENSITY PROBABILITY SIGNIFICANCE CONSEQUENCE CONFIDENCE

Biophysical impacts

Surface Water

Description: Should the decommissioning philosophy be to make use of the site infrastructure to the benefit of the community, impacts will remain similar to those in commissioning and operation phases with a strong emphasis on maintaining surface water management systems.

Without Local Short-term High Probable Low Low Medium

(a) Impact 1: Localised flooding due to siltation of surface water management systems


Description: Should the decommissioning philosophy be to make use of the site infrastructure to the benefit of the community, impacts will remain similar to those in commissioning and operation phases with a strong emphasis on maintaining surface water management systems.




Wetlands

No impacts associated with the de-commissioning phase were assessed.

Ground Water

Description: The risk of radioactive and toxic contamination of groundwater will intensify during the decommissioning phase as a result of transfer of these substances off Site.

Without Regional Medium-term

High Improbable Medium Medium Medium

(a) Impact 1: Radioactive and toxic contamination of groundwater due to nuclear by-product leaks and spillages.



10-44

Potential de-commissioning phase impacts








(c) Impact 3: Degradation of the lower raft and retaining walls concrete, as well as soil cement sub-foundation by groundwater With Local Short-term Low Improbable Low Low High



(d) Impact 4: Organic and bacterial contamination of groundwater due to on-site sanitation facilities’ leaks and spillages. With Local Short-term Low Improbable Low Low High



(e) Impact 5: Hydrocarbon contamination of groundwater due to fuel, oil and grease storage facilities’ leaks and spillages. With Local Short-term Low Improbable Low Low High

Fauna

No De-commissioning impacts were assessed as impacts are anticipated to be restricted to the construction phase.

Flora

No De-commissioning impacts were assessed as impacts are anticipated to be restricted to the construction phase.


10-45




Decommissioning of the proposed PBMR DPP is not expected to have a significant impact on the marine environment as the development will occur totally within the terrestrial environment.


Social Environment




With Local Short-term Low Highly Probable Low low High


Without Local Short-term Medium Definite High Medium High


With Local Short-term Medium Highly probable Low Low High


Without Local Short-term Low to medium






Without Local Short-term Medium Highly probable Medium Medium High


With Local Short-term Medium Highly probable Low to medium Low High


10-46









Without Local to Regional

Short-term Low Improbable Low Low High




Without Regional Short-term Low to Medium

Improbable Low Low High








Without National Short-term Low Improbable to probable

Low Low to medium High




10-47



Land Use





Description: The ability to achieve enhanced development rights is directly related to the future growth and development of the city within the study area. Enhanced development rights in the form of, e.g., rezoning *such as agricultural to residential) or subdivision is the mechanism by which urban areas expand and change over time. The ability of the land within the 5 km PAZ to acquire enhanced development rights is curtailed by the current development controls applicable to Koeberg, the Atlantis Guide Plan (1981) and the more recent Urban Edge Reports. It is likely that the lifespan of the PBMR DPP will exceed that of KNPS. Landuse controls that limit the development of land within the 5 km PAZ will therefore continue after KNPS is decommissioned and the same conditions that affect the ability to achieve enhanced development rights will be applicable. The impact is acceptable, since the City of Cape Town’s future growth is not limited to the area within the 5 km PAZ. Even though the impact is acceptable it is still regarded as a high significance impact due to the fact that the restrictions imposed by the PAZ will never be relaxed, unless the KNPS reaches end of life sometime in the future and the 5 km PAZ is revised









10-48



Heritage

No impacts are anticipated during the de-commissioning phase

Visual

No impacts are anticipated during the de-commissioning phase


10-49

Table 10.5: Summary of potential environmental impa cts for the Construction Phase

IMPACT SIGNIFICANCE POTENTIAL CONSTRUCTION PHASE IMPACTS WITHOUT

MITIGATION WITH

MITIGATION

Biophysical impacts Surface Water

Impact 1: Erosion of Surface Soils Low Low

Impact 2: Contamination of Surface Runoff Low Low Wetlands

Impact 1: Loss of Ficinia nodosa wetlands – assessed without consideration of downstream knock-on impacts

Medium Mitigation not

possible

Impact 2: Loss of buffering capacity for adjacent seasonal wetlands High Medium

Impact 3: Impacts associated with dewatering – drying of wetlands and increased groundwater salinity (Seasonal wetlands)

High Low

Impact 4: Impacts associated with receipt of runoff from disturbed areas (Seasonal wetlands)

Medium Low to medium

Impact 5: Impacts associated with physical disturbance and noise from construction and laydown areas (Seasonal Wetlands)

Medium Low

Impact 6: Impacts associated with dewatering – drying of wetlands and increased groundwater salinity (Wetlands P6 and P7)

Medium Low

Impact 7: Impacts associated with receipt of runoff from disturbed areas (wetlands P6 and P7)

Medium Low

Impact 8: Impacts associated with physical disturbance and noise from construction and laydown area (Wetlands P6 and P7)

Low Low

Impact 9: Impacts associated with the construction and once off use of a causeway over the Modder River

High Low

Impact 10: Impacts associated with the construction of a 132 kV sub-transmission line

Medium Low

Impact 11: Impacts to P6 associated with the construction of a pipe line Low Low Ground Water

Impact 1: Flooding of the excavated areas by groundwater Low Low

Impact 2: Lowering of the water table due to dewatering and pumping of groundwater for construction use

Low Low

Impact 3: Intrusion of saline water due to dewatering and pumping of groundwater for construction use

Medium Low

Impact 4: Drying up of coastal springs and / or seeps due to dewatering and pumping of groundwater for construction use

Medium Low

Impact 5: Drying up of wetlands due to dewatering and pumping of groundwater for construction use

Medium Low

Impact 6: Decreased yields of existing production boreholes due to dewatering and pumping of groundwater for construction use

Low Low

Impact 7: Organic and bacterial contamination of groundwater due to on-site sanitation facilities’ leaks and spillages

Low Low

Impact 8: Hydrocarbon contamination of groundwater due to fuel, oil and grease storage facilities’ leaks and spillages

Low Low

Air Quality

Impact 1: PM10 Low Low

Impact 2: PM deposition Low Low Fauna

Impact 1: PBMR DPP – habitat destruction Low Low

Impact 2: PBMR DPP – Dust pollution off site Low Low

Impact 3: PBMR DPP – Chemical pollution of soil and groundwater Medium Low


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Impact 4: PBMR DPP – lowered water table and attendant degeneration of wetlands on site

Assessed by Groundwater Study

Impact 5: PBMR DPP – Disruption of the ecology of local seasonal wetlands by pumped groundwater

High Low

Impact 6: PBMR DPP – Poaching of animals especially larger animals Low Low

Impact 7: PBMR DPP – Disruption of breeding of regionally important bird populations

Medium Low

Impact 8: 132 kV Transmission line – Destruction of wetland habitat High Low

Impact 9: Modification to Modder River – Destruction of sensitive wetland habitat

High Low

Impact 10: Modification to Modder River crossing – Destruction of unspoilt terrestrial habitat

High Low

Impact 11: Modification of Modder River crossing – Disturbance of downstream water flow with attendance degradation of wetland habitats

Medium Low

Impact 12: Modification of Modder River crossing – Disruption of faunal movements within the riparian corridor

Medium Low

Impact 13: Laydown areas – Extensive destruction of pristine natural habitats

High Low

Impact 14: Laydown areas – Dust pollution off site Low Low

Impact 15: Laydown areas – Chemical pollution of soil and groundwater Medium Low

Impact 16: Laydown areas – Polluted run-off degrading nearby wetlands Medium Low

Impact 17: Laydown areas – Poaching of animals, especially larger mammals

Low Low

Impact 18: Disruption of animal movements and mortality associated with trenches

Low Low

Impact 19: Dust pollution off site Low Low

Impact 20: Chemical pollution of soil and groundwater Medium Low

Impact 21: Polluted runoff degrading nearby wetlands Medium

Impact 22: Poaching of animals, especially larger mammals Low Low

Impact 23: Long-term degradation of habitats Medium Low Flora

Impact 1: PBMR DPP and adjacent laydown area – Loss of wetland flora and habitat in the south

High Medium

Impact 2: PBMR DPP and adjacent laydown area – Impact on primary dune system

High Low

Impact 3: Alternative laydown area A – Habitat loss at the coast High Low

Impact 4: Alternative laydown area A – Habitat loss inland Low Low

Impact 5: Triangle laydown areas to east of R27 – Loss of Sand Plain Fynbos habitat

Medium Low to medium

Impact 6: Triangle laydown area to east of R27 – Loss of Dune Thicket / Sand Plain Fynbos habitat

High Low

Impact 7: Powerlines – Construction and placing of towers High Low

Impact 8: Modder river causeway – construction and placing of causeway

Medium Medium

Impact 9: Water Pipeline – Section 1 (R27) Medium Low Impact 10: Water Pipeline – Section 2 (power lines and firebreak) Medium Low Impact 11: Water Pipeline – Section 3 (internal road) Medium Low Impact 12: Water Pipeline – Section 4 (disturbed veld and dune) Medium Low Impact 13: Water Pipeline – Section 5 (PBMR Site) Medium Low Marine Fauna and Flora Impact 1: Release of saline groundwater during dewatering of the proposed site

Low N/A1

Impact 2: Organic and Bacterial contamination resulting from discharge Low Low

1 No mitigation proposed


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of contaminated groundwater Impact 3: Hydrocarbon contamination resulting from discharge of contaminated groundwater

Low Low

Socio- cultural/ socio-economic impacts Social Environment

Impact 1: Introduction of people dissimilar in demographic profile Low Low

Impact 2: impact commensurate with inflow of temporary workers High Low

Impact 3: Local / Metropolitan Government impacts Low to medium Low to medium

Impact 4: Impact on daily movement patterns Medium Low to medium

Impact 5: Public health and safety Low Low Economic Environment

Impact 1: Employment creation Low Low

Impact 2: Employment equity and inequity Low Low

Impact 3: Property Values Low Low

Impact 4: Tourism Low Low

Land Use

Impact 1: Effect on existing development rights and use Low N/A2

Impact 2: The ability to achieve enhanced development rights High N/A3

Impact 3: Conservation of agricultural land uses High N/A4 Heritage

Impact 1: PBMR DPP Site – Bulk excavation impacts to Pleistocene Palaeontology / archaeology

Medium Low

Impact 2: PBMR DPP Site – Bulk excavation impacts to Palaeontology (Cenozoic)

Medium Low

Impact 3: PBMR DPP Site – Impacts of construction on the cultural landscape

Low Low

Impact 4: Impacts of construction of the laydown areas on palaeontology and archaeology

Low Low

Impact 5: Impacts of the construction of the laydown areas on the cultural landscape

Low Low

Impact 6: Impacts of construction of the alternative laydown area on palaeontology / archaeology

Medium Low

Impact 7: Impacts of the construction of the alternative laydown areas on the cultural landscape

Low Low

Impact 8: Impacts of modifications of the R27 on palaeontology / archaeology

Low Low

Impact 9: Impacts of modifications of the R27 on the cultural landscape N/A5 N/A

Impact 10: Impacts of construction of access roads on generally protected heritage

Low Low

Impact 11: Impacts of construction of the 132 kV transmission line on generally protected heritage

Low Low

Impact 12: Impacts of potable water pipeline on generally protected heritage

Low Low

Visual

Impact 1: Visual impact PBMR DPP Medium Medium

Impact 2: Visual impact – Laydown area Low Low

Impact 3: Visual impact – Transmission line Low Low

2 No mitigation proposed 3 No mitigation proposed 4 No mitigation proposed 5 The R27 is not a protected linear feature, impacts are not expected


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Table 10.6: Summary of potential environmental impa cts for the Commissioning Phase

IMPACT SIGNIFICANCE POTENTIAL COMMISSIONING PHASE IMPACTS WITHOUT

MITIGATION WITH

MITIGATION


Impact 1: Localised flooding due to siltation of surface water management systems

Low Low

Impact 2: Removal of surface water recharge from wetland systems High Low Wetlands

Impact 1: Contamination of wetlands as a result of leakage of nuclear by-product into groundwater

High Low

Impact 2: Changes in surface water flows associated with the hardening of laydown areas

High Low to medium

Ground Water

Impact 1: Radioactive and toxic contamination of groundwater due to uranium and helium leaks and spillages

Medium Low

Impact 2: Flooding of the reactor by groundwater inflows Medium Low

Impact 3: Degradation of the lower raft and retaining walls concrete as well as cement foundations by groundwater

Low Low

Impact 4: Organic and bacterial contamination of groundwater due to onsite sanitation facilities’ leaks and spills

Low Low

Impact 5: Hydrocarbon contamination of groundwater due to fuel, oil and grease storage facilities’ leaks and spillages

Low Low

Impact 6: Lowering of the water table due to pumping of groundwater for use

Low Low

Impact 7: Intrusion of saline water due to pumping of groundwater for use

Low Low

Impact 8: Drying up of coastal springs and / or seeps due to pumping of groundwater for use

Low Low

Impact 9: Drying up of wetlands due to pumping of groundwater for use Low Low

Impact 10: Decreased yields of existing production boreholes due to pumping of groundwater for use

Low Low

Marine Fauna and Flora Impact 1: Organic and Bacterial contamination resulting from discharge of contaminated groundwater Low Low

Impact 2: Hydrocarbon contamination resulting from discharge of contaminated groundwater

Low Low

Impact 3: Radioactive contamination resulting from discharge of contaminated groundwater

Low Low



Impact 2: Impact commensurate with inflow of temporary workers Low Low

Impact 3: Local / Metropolitan Government impacts Low Low

Impact 4: Impact on daily movement patterns Low Low

Impact 5: Public health and safety Low Low


Impact 1: Employment creation Medium Medium

Impact 2: Employment Equity and Inequity Medium Low

Impact 3: Property Values Low Low


Land Use


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Impact 2: The ability to achieve enhanced development rights High N/A

Impact 3: Conservation of agricultural land uses High N/A

6 No Mitigation Proposed


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Table 10.7: Summary of potential environmental impa cts for the Operation Phase

IMPACT SIGNIFICANCE POTENTIAL OPERATION PHASE IMPACTS WITHOUT

MITIGATION WITH

MITIGATION

Biophysical impacts Oceanography

Impact 1: Flooding due to extreme waves Low N/A7

Impact 2: Flooding due to extreme water levels Low N/A8

Impact 3: Flooding due to tsunamis Low N/A9

Impact 4: Exposure of cooling water intake pipes under tsunami conditions

Low Low

Impact 5: Damage to intake basins Low N/A10

Impact 6: Erosion or accretion of surrounding sediment Low N/A11

Impact 7: Sedimentation within the intake basin Low N/A12

Impact 8: Blockage of cooling water intake pipes Low N/A13 Seismic Risk

Impact 1: Possible vibratory ground motion of the site Low Low

Impact 2: Short period tectonic changes in the existing geology, whether from rock fall or other kinds of rock movement within a radius of 230 km.

High Low

Impact 3: Movements along any of the known faults or a new fault within a radius of 320 km

High Low

Impact 4: Tsunami Flooding Medium Low

Impact 5: Collapsing rock slopes within a radius of 8 km Low Low Surface Water


Low Low

Impact 2: Removal of surface water recharge from wetland systems High Low Wetlands

Impact 1: Contamination of wetlands as a result of leakage of radioactive material into groundwater

High Low

Impact 2: Changes in surface water flows associated with hardening of portions of the catchment

High Low to medium

Impact 3: Changes in wetland hydro-period resulting from groundwater abstraction

High N/A14

Ground Water


Medium Low


Impact 3: Degradation of the lower raft and retaining walls concrete, as well as cement sub-foundations by groundwater

Low Low


Low Low

Impact 5: Hydrocarbon contamination of groundwater due to fuel. Oil and grease storage facilities’ leaks and spillages

Low Low

Impact 6: Lowering of the water table due to pumping of groundwater for Low Low

7 No mitigation considered necessary 8 No mitigation considered necessary 9 No mitigation considered necessary 10 No mitigation considered necessary 11 No mitigation considered necessary 12 No mitigation considered necessary 13 No mitigation considered necessary 14 No mitigation proposed


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use

Impact 7: Intrusion of saline water due to pumping of groundwater for use

Low Low

Impact 8: Drying up of coastal springs and / or seeps due to pumping of groundwater for use

Low Low

Impact 9: Drying up of wetlands due to pumping of groundwater for use Low Low

Impact 10: Decreased yields of existing production boreholes due to pumping of groundwater for use

Low Low

Air Quality

Impact 1: Radiation Dose Low N/A15 Fauna

Impact 1: Transmission Power Line – Fatal collisions of birds with the powerline

Medium Low

Marine Fauna and Flora Impact 1: Organic and Bacterial contamination resulting from discharge of contaminated groundwater Low Low

Impact 2: Hydrocarbon contamination resulting from discharge of contaminated groundwater

Low Low

Impact 3: Radioactive contamination resulting from discharge of contaminated groundwater

Low Low

Impact 4: Increased mortality of marine organisms during cooling water abstraction

Low N/A16

Impact 5: Impact of mixed Koeberg and PBMR DPP cooling water discharge (26.6ºC) on the marine environment

Low N/A

Impact 6: Impact of PBMR DPP cooling water discharge (39.9ºC) on the marine environment

Medium Low

Impact 7: Radiation emissions Low N/A

Impact 8: Radioactive contamination of the marine environment as a result of a nuclear accident

High High

Socio- cultural/ socio-economic impacts Radiological Safety and Health

Impact 1: Cumulative impact of gaseous and liquid emissions on the environment during normal operating conditions

Low N/A17

Impact 2: Cumulative impact on Vaalputs waste disposal site Low N/A

Impact 3: Cumulative impact of transport of radioactive waste Low N/A

Impact 4: Cumulative impact on emergency response planning during normal operating conditions

Low N/A

Impact 5: Cumulative impact on emergency response planning following an accident

Low N/A

Impact 6: Cumulative impact of gaseous emissions on the environment during accident conditions

Low N/A

Social Environment

Impact 1: Introduction of people dissimilar in geographic profile Low Low

Impact 2: Impact commensurate with inflow of temporary workers Low Low

Impact 3: Local / Metropolitan Government Impacts Low Low

Impact 4: Impact on daily movement patterns Low Low

Impact 5: Public Health and safety Low Low Economic Environment

Impact 1: Employment creation Medium Medium

Impact 2: Employment equity and inequity Medium Low

Impact 3: Property values Low Low

15 Mitigation considered not applicable 16 No mitigation considered necessary 17 No mitigation considered necessary


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Land Use



Impact 3: Conservation of agricultural land uses High N/A Visual

Impact 1: Visual Impact – PBMR DPP Medium Medium

Impact 2: Visual Impact – Transmission Line Low Low



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Table 10.8: Summary of potential environmental impa cts for the De-commissioning Phase

IMPACT SIGNIFICANCE POTENTIAL DE-COMMISSIONING PHASE IMPACTS WITHOUT

MITIGATION WITH

MITIGATION



Low Low

Impact 2: Removal of surface water recharge from wetland systems High Low Ground Water


Medium Low


Impact 3: Degradation of the lower raft and retaining walls concrete, as well as soil cement sub-foundation by groundwater

Low Low


Low Low

Impact 5: Hydrocarbon contamination of groundwater due to fuel, oil and grease storage facilities’leaks and spilalges

Low Low



Impact 2: Impact commensurate with inflow of temporary workers High Low

Impact 3: Local / Metropolitan Government Impacts Low to medium Low to medium

Impact 4: Impact on daily movement patterns Medium Low to medium

Impact 5: Public health and safety Low Low Economic Environment

Impact 1: Employment creation Low Low

Impact 2: Employment equity and inequity Low Low

Impact 3: Property values Low Low


Land Use



Impact 3: Conservation of agricultural land uses High N/A



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10.2 Cumulative Impacts

10.2.1 Air Quality

The main findings from the operation of the proposed PBMR DPP are that for continuous radionuclide releases, predicted radiation dose at ground level was less than 1% of the Public Dose Criteria (250 µSv/yr) as stipulated by the NNR (2007) for incremental and cumulative scenarios. For continuous gaseous radiation releases, predicted radiation dose at ground level is less than 1% of the Public Dose Criteria as stipulated by the NNR (2007) for incremental and cumulative scenarios. As the Public Dose Criteria was established for the protection of human health, the predicted radiation dose due to normal operations of the PBMR DPP is predicted to be within “safe” levels

10.2.2 Fauna

The erection of the PBMR DPP to the south of KNPS, with the possibility of a second conventional nuclear power station just to the north of KNPS, presents the prospect of a long, solid barrier of buildings and associated infrastructure between the coast and the inland portions of Koeberg. Not only will these developments have a disproportionate impact on coastal habitats, but they have the potential to isolate inland fauna from the coast which, for many species, is an important foraging area. This cumulative negative impact can be ameliorated by the creation of ecological corridors that link inland areas with the coast. The importance of such a corridor to the south of the PBMR DPP has been discussed.

An additional consideration in this regard, is the type of security arrangements which are put in place along the coast. The mesh fencing presently used is highly unsuitable in that it presents an impenetrable barrier to all but the smallest animals. Far preferable is palisade fencing with gaps wide enough to allow most animals to pass through. The possibility of cumulative impacts also arises with respect to routine emissions of radioactive material. Additional reactors will presumably lead to additional emissions and the possibility of reaching damaging thresholds of pollution in the surrounding ecosystem. This danger must be addressed by means of adequate monitoring programmes that will determine whether the accumulation of radioactive isotopes in the bodies of local animals is approaching dangerous levels

10.2.3 Surface Water During construction, extensive earthworks will be undertaken both at the laydown site and at the Nuclear Reactor site. It has been mentioned that the Sites have flat gradients and it is logical that these flat gradients will define low surface water flow velocities, reducing potential erosion risks. However, surface soils are non-cohesive and erosion related to rain events will be a concern. It is likely that such erosion may not produce significant scars (gulleys, etc) in surface soils, but the normal functioning of stormwater management infrastructure (surface drains, pipes etc) could be severely impeded by siltation resulting from surface soil erosion. This impact will be a


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cumulative impact, exacerbated with time. Mitigation will require strict control of site runoff during construction. This will require specifications documented in an Environmental Management Plan (EMP) to control runoff during construction.

10.2.4 Marine Biology

Although the previous studies undertaken regarding the discharge of cooling water into the ocean considered only the impacts of the Koeberg Nuclear Power Station (i.e. the release of water at 25.5ºC (assuming an intake temperature of 15ºC)) and not the collective effect of the existing power station and the proposed PBMR DPP, their conclusions are still deemed valid. This is due to the fact that the volume of water released by the proposed PBMR DPP will be 34 times less than that released by Koeberg (PBMR Company 2007) As a result, with both power stations operating the water leaving the outfall pipe will reach a maximum of 28ºC i.e. less than 3.5ºC higher than that released by Koeberg alone (PBMR Company 2007). Thus no significant cumulative effect is predicted and no mitigation measures are necessary for this impact. It is, however, important to note that should the proposed PBMR DPP release water of 39.9ºC independently from the Koeberg Nuclear Power Station (i.e. no mixing of the release water from the two power stations) into the marine environment, the impacts are likely to be significant and much more severe than those described above (Cook 1978). In mitigation of such impacts, it is recommended that should the PBMR DPP operate alone, cooling water should never be released back into the marine environment before being further cooled to at least 28ºC.

10.3 Proposed Laydown Areas

Specialists were requested to assess the alternative laydown areas that were proposed by the Eskom project team as well as to identify any areas that may be considered more appropriate in terms of environmental impacts. A discussion of the various laydown areas and the assessments undertaken are included in chapter 9 of this report. The sensitivity analysis undertaken by the specialists was combined into a single map showing the overall sensitivity of the site and the appropriateness of the various laydown areas for use. See Figure 10.1 for this map. The triangle laydown area situated along the R27 and the laydown area identified on the “sea-side” of the PBMR site are considered to be acceptable for use.


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Figure 10.1: Combined analysis regarding the most preferred laydown areas.


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10.4 Conclusion

10.4.1 Construction phase impacts

During the construction phase, the majority of impacts identified were considered to be of low to medium significance in the event that the appropriate mitigation measures are implemented. The following impacts were assessed to be of high significance in the event that mitigation measures are not implemented as required: • Wetlands

o Impacts associated with the loss of buffering capacity for adjacent seasonal wetlands

o Impacts associated with dewatering – drying of wetlands and increased groundwater salinity in seasonal wetlands

o Impacts associated with the construction and once-off use of a causeway over the Modder River

• Fauna o The disruption of the ecology of local seasonal wetlands by pumped

groundwater o Destruction of wetland habitat due to the construction of a 132 kV

Transmission line o Destruction of sensitive wetland habitat due to the modification of the

Modder river o Destruction of unspoilt terrestrial habitat due to the modification of the

Modder river o Extensive destruction of pristine natural habitat due to laydown areas

• Flora o The loss of wetland flora and habitat due to the PBMR DPP and adjacent

laydown area o Impacts on the primary dune system due to the PBMR DPP and adjacent

laydown area o Habitat loss at the coast due to Alternative laydown area A o Loss of Dune Thicket and Sand Plain Fynbos habitat due to the Triangle

laydown area to the east of the R27 o Impacts as a result of the construction and placement of towers for the

power lines • Social Environment

o Impact associated with the inflow of temporary workers The following high significance impacts remain of high significance as no mitigation measures can be proposed: • Land Use

o Impacts associated with the ability to achieve enhanced development rights - The ability to achieve enhanced development rights is directly related to the future growth and development of the city within the study area. Enhanced development rights in the form of, e.g., rezoning *such as agricultural to residential) or subdivision is the mechanism by which urban areas expand and change over time. The ability of the land within the 5 km PAZ to acquire enhanced development rights is curtailed by the current


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development controls applicable to Koeberg, the Atlantis Guide Plan (1981) and the more recent Urban Edge Reports. It is likely that the lifespan of the PBMR DPP will exceed that of KNPS. Landuse controls that limit the development of land within the 5 km PAZ will therefore continue after KNPS is decommissioned and the same conditions that affect the ability to achieve enhanced development rights will be applicable. The impact is acceptable, since the City of Cape Town’s future growth is not limited to the area within the 5 km PAZ. Even though the impact is acceptable it is still regarded as a high significance impact due to the fact that the restrictions imposed by the PAZ will never be relaxed, unless the KNPS reaches end of life sometime in the future and the 5 km PAZ is revised

o Impacts associated with the conservation of agricultural land uses - The 5 km PAZ limits the development and use of land to the existing zoning. 94,6% (7 305,7 ha) of the land within the PAZ boundary is zoned agriculture. Under the current and future development controls for the 5 km PAZ, this land will remain within the agricultural basket of uses. The impact is acceptable in light of the need to conserve agricultural land. The retention of the agricultural zoning prevents the land from being used for urban uses. Where agricultural activities cease, the potential to more the land into a conservation –type use, become available. Even though the impact is acceptable it is still regarded as a high significance impact due to the fact that the restrictions imposed by the PAZ will never be relaxed, unless the KNPS reaches end of life sometime in the future and the 5 km PAZ is revised

A total of nineteen (19) impacts were assessed as having a high intensity20 before the implementation of mitigation measures. After the implementation of mitigation measures the intensity levels of all impacts dropped. The impact on the irreplaceable resources associated with the above-mentioned impacts, would be high in the event that mitigation measures are not implemented. However, after the implementation of the recommended mitigation measures included in the EMP the impact on the resources listed below will be minimised to an acceptable level. • Surface soils; • Surface run-off; • Wetlands; • Riverine habitat; • Regionally important bird populations; • Pristine natural habitats and veld types; and • Primary dune systems.

During the construction phase four (4) impacts could be deemed to be potential risks to human health and safety. Three of these impacts were found to be of low significance both before and after mitigation. These impacts include the release and deposition of dust and the potential negative nuclear related health impacts and other safety risks related to the construction phase. One impact, the potential increase of antisocial behaviour due to the influx of temporary workers and job seekers into the area, was considered to be of high significance before mitigation measures are implemented and of low significance after mitigation. Therefore, as long as the relevant mitigation measures are implemented no substantive risk to human health and safety has been identified.

20 The rating of impact intensity includes cumulative impacts, impact non-reversibility and impact on irreplaceable resources.


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The impacts where specialist confidence rated the lowest relate to impacts associated with dewatering and the pollution of groundwater. The lack of confidence is not necessarily related to lack of information, but rather to the specialists’ lack of certainty regarding the effectiveness of the proposed mitigation measures.

10.4.2 Commissioning phase impacts

As with the construction phase, the majority of impacts identified associated with the commissioning phase were considered to be of low to medium significance in the event that the appropriate mitigation measures are implemented. The following impacts were assessed to be of high significance in the event that mitigation measures are not implemented as required: • Seismic Risk

o Short period tectonic changes in the existing geology, whether from rock fall or other kinds of rock movement within a radius of 230 km

o Movements along any of the known faults or a new fault within a radius of 320 km

• Surface water o Removal of the surface water recharge from wetland systems

• Wetlands o Contamination of wetlands as a result of nuclear by-products into

groundwater o Changes in surface water flows associated with the hardening of laydown

areas As with the construction phase, the following high significance impacts remain of high significance as no mitigation measures can be proposed: • Land Use

o Impacts associated with the ability to achieve enhanced development rights

o Impacts associated with the conservation of agricultural land uses A total of five (5) impacts were assessed as having a high intensity21 before the implementation of mitigation measures. After the implementation of mitigation measures the intensity levels of all impacts dropped. The impact on the irreplaceable resources associated with the above-mentioned impacts, would be high in the event that mitigation measures are not implemented. However, after the implementation of the recommended mitigation measures included in the EMP the impact on the resources listed below will be minimised to an acceptable level • Surface soils • Surface water • Wetlands; and • Groundwater The ability to achieve enhanced development rights as well as employment equity are also two of the impacts with a high intensity. However these impacts will not affect irreplaceable resources.



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During the commissioning phase fifteen (15) impacts could be deemed to be potential risks to human health and safety. The majority of these impacts deal with the potential contamination of environmental media by nuclear and non-nuclear substances. After assessment 13 impacts were found to be of low significance both before and after mitigation. These impacts include: • Organic and bacterial contamination of groundwater from on-site sanitation

facilities; • Hydrocarbon contamination of groundwater due to fuel, oil and grease storage

facilities; • Radiation dose (in terms of air quality); • Organic and bacterial contamination resulting from contaminated groundwater on

the marine environment; • Hydrocarbon contamination resulting from contaminated groundwater on the

marine environment; • Radioactive contamination resulting from contaminated groundwater on the

marine environment; • Cumulative impact of gaseous and liquid emissions on the environment during

normal operating conditions; • Cumulative impact of transport of radioactive waste; • Cumulative impact on emergency response planning during normal operating

conditions; • Cumulative impact on the emergency response planning following an accident; • Cumulative impact of gaseous emissions on the environment during accident

conditions; • Potential increase of antisocial behaviour due to the influx of temporary workers

and job seekers into the area; and • Potential negative nuclear related health impacts and other safety risks Two impact (the contamination of wetlands as a result of leakage of nuclear by-products into groundwater and the radioactive and toxic contamination of groundwater due to nuclear by-products, leaks and spillages) were considered to be of high and medium significance respectively, before mitigation measures are implemented and of low significance after mitigation. Therefore, as long as the relevant mitigation measures are implemented no substantive risk to human health and safety has been identified. The impacts where specialist confidence rated the lowest relate to impacts associated with wetlands, specifically contamination as a result of the leakage of nuclear by-products into groundwater and the changes in surface flows associated with the hardening of laydown areas.

10.4.3 Operational phase impacts

The majority of the impacts identified, associated with the operational phase were considered to be of low to medium significance in the event that the appropriate mitigation measures are implemented. The following impacts were assessed to be of high significance in the even that mitigation measures are not implemented as required: • Seismic Risk

o Short period tectonic changes in the existing geology, whether from rock fall or other kinds of rock movement within a radius of 230 km


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o Movements along any of the known faults or a new fault within a radius of 320 km

• Surface water o Removal of the surface water recharge from wetland systems

• Wetlands o Contamination of wetlands as a result of nuclear by-products into

groundwater o Changes in surface water flows associated with the hardening of laydown

areas The following high significance impacts remain of high significance as no mitigation measures can be proposed: • Land Use


o Impacts associated with the conservation of agricultural land uses • Wetlands

o Changes in wetland hydro-period resulting from groundwater abstraction – however, it should be noted that all potable and construction water will be sourced via a water pipeline that will link directly into municipal infrastructure. No groundwater abstraction will therefore be required.

Only one impact was identified to remain at high significance even after the implementation of mitigation measures, these include: • Marine Fauna and Flora

o Radioactive contamination of the marine environment as a result of a nuclear accident - Should a large scale nuclear accident occur and the cooling system be breached in such a way that the sea water taken up for cooling purposes comes into direct contact with the damaged reactor, radioactive contamination of the marine environment may occur. Although the intensity of such an impact would be high, the probability of this occurring is low and extent is likely to be localised

A total of twenty-one (21) impacts were assessed as having a high intensity22 before the implementation of mitigation measures. After the implementation of mitigation measures the intensity levels of all impacts dropped. The impact on the irreplaceable resources associated with the above-mentioned impacts, would be high in the event that mitigation measures are not implemented. However, after the implementation of the recommended mitigation measures included in the EMP the impact on the resources listed below will be minimised to an acceptable level • Surface soils; • Surface water • Wetlands; • Groundwater; • Marine environment; and • Air quality. The following impacts were assessed to have a high intensity, however, they are not considered to be associated to the loss of irreplaceable resources:



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• Flooding due to extreme waves; • Flooding due to extreme water levels; • Flooding due to Tsunami’s; • Exposure of cooling water intake pipes under Tsunami conditions; • Damage to intake basins; • Sedimentation within the intake basin; • Blockage of cooling water intake pipes; • Short period tectonic changes in the existing geology; • Movements along any of the known faults or a new fault; • Cumulative impact on Vaalputs waste disposal site; • Cumulative impact of transport of radioactive waste; • Cumulative impact on emergency response planning during normal operating

conditions; • Cumulative impact on the emergency response planning following an accident • Employment equity; • Enhanced development rights.

During the operational phase seventeen (17) impacts could be deemed to be potential risks to human health and safety. The majority of these impacts deal with the potential contamination of environmental media by nuclear and non-nuclear substances. After assessment 14 impacts were found to be of low significance both before and after mitigation. These impacts include: • Organic and bacterial contamination of groundwater from on-site sanitation

facilities; • Hydrocarbon contamination of groundwater due to fuel, oil and grease storage

facilities; • Radiation dose (in terms of air quality); • Organic and bacterial contamination resulting from contaminated groundwater on

the marine environment; • Hydrocarbon contamination resulting from contaminated groundwater on the

marine environment; • Radioactive contamination resulting from contaminated groundwater on the

marine environment; • Radiation emissions (in terms of the marine environment); • Cumulative impact of gaseous and liquid emissions on the environment during

normal operating conditions; • Cumulative impact of transport of radioactive waste; • Cumulative impact on emergency response planning during normal operating

conditions; • Cumulative impact on the emergency response planning following an accident; • Cumulative impact of gaseous emissions on the environment during accident

conditions; • Potential increase of antisocial behaviour due to the influx of temporary workers

and job seekers into the area; and • Potential negative nuclear related health impacts and other safety risks Two impacts (the contamination of wetlands as a result of leakage of nuclear by-products into groundwater and the radioactive and toxic contamination of groundwater due to nuclear by-products, leaks and spillages) were considered to be of high significance before mitigation measures are implemented and of low


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significance after mitigation. Therefore, as long as the relevant mitigation measures are implemented no substantive risk to human health and safety has been identified. One impact (the radioactive contamination of the marine environment as a result of a nuclear accident) is considered to be of high significance both before and after mitigation. However, due to the improbability of this impact occurring it is not seen as a substantive risk. Therefore, as long as the relevant mitigation measures are implemented no substantive risk to human health and safety has been identified. The impacts where specialist confidence rated the lowest relate to impacts associated with wetlands, specifically contamination as a result of the leakage of nuclear by-products into groundwater, the changes in surface flows associated with the hardening of portions of the catchment and changes in wetland hydroperiod resulting from groundwater abstraction. During the operational phase, additional risks may become apparent that could impact the effective implementation of this technology. These could include inter alia:

• Failure to receive a Nuclear License to operate the plant; or • Failure to meet the relevant demonstration criteria.

In such events this would trigger the decommissioning phase of the project. A certificate of registration which involves the decommissioning of any nuclear installation plant or equipment having an impact on the radiation protection and nuclear safety, or the release of radioactively contaminated land for other uses would be required. The details of the requirements of such a certificate is fully described in the Radiological Safety and Health and Radiological Waste Management Studies included in Appendices AL and AO respectively.

10.4.4 Decommissioning phase impacts

As with the construction, commissioning and operational phases, the majority of impacts identified associated with the de-commissioning phase were considered to be of low to medium significance in the event that the appropriate mitigation measures are implemented. The following impacts were assessed to be of high significance in the even that mitigation measures are not implemented as required: • Surface water

o Removal of the surface water recharge from wetland systems • Social Environment

o Impact associated with the inflow of temporary workers

As with all the above-mentioned phases, the following high significance impacts remain of high significance as no mitigation measures can be proposed: • Land Use


o Impacts associated with the conservation of agricultural land uses


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A total of four (4) impacts were assessed as having a high intensity23 before the implementation of mitigation measures. After the implementation of mitigation measures the intensity levels of all impacts dropped. The impact on the irreplaceable resources associated with the above-mentioned impacts, would be high in the event that mitigation measures are not implemented. However, after the implementation of the recommended mitigation measures included in the EMP the impact on the resources listed below will be minimised to an acceptable level • Surface soils; • Surface water • Wetlands; and • Groundwater. The ability to achieve enhanced development rights is also one of the impacts with a high intensity. However, this impact will not affect an irreplaceable resource. During the decommissioning phase four (4) impacts could be deemed to be potential risks to human health and safety. After assessment 3 impacts were found to be of low significance both before and after mitigation. These impacts include the organic and bacterial contamination of groundwater from on-site sanitation facilities, the hydrocarbon contamination of groundwater due to fuel, oil and grease storage facilities and the potential negative nuclear related health impacts and other safety risks. One impact, the radioactive and toxic contamination of groundwater due to nuclear by-products, leaks and spillages, was considered to be of medium significance before mitigation measures are implemented and of low significance after mitigation. Therefore, as long as the relevant mitigation measures are implemented no substantive risk to human health and safety has been identified. A full description of the decontamination processes for the PBMR DPP that would be required on decommissioning is listed in Section 5.3 of the Radiological Safety and Health Study, included in Appendix AL .


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Ch 10 Impact Analysis 05.09 - GIBB