Dismantling of the turbine hall at Greifswald NPP · “Dismantling of the turbine hall at Greifswald NPP” ... Tube milling machine with pneumatic drive Ø ... C-Steel Up to 10

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EWN – Energiewerke Nord GmbH

Germany

“Dismantling of the turbine hall

at Greifswald NPP”

planning issues and practical work

IAEA training course on advanced cutting technologies 05 - 08 Sept. 2011

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Dismantling of the turbine hall

Contents

1. General facts on the turbine hall dismantling

– Summary on dismantling work 1996 - 2007

2. Training for manual dismantling at EWN

3. General licensing (planning) approach

4. Dismantling planning for the turbine hall (supervised area)

– Main strategies

– Detailed planning and boundary conditions

5. Practical dismantling execution

– Realisation of the work on selected examples

Contents

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Turbine hall dismantling - masses and work duration

Total amount of material in the turbine hall Per unit: 10.1 thousand Mg

Sum of units 1 - 5 50.7 thousand Mg

Radiological classification of materials in turbine hall units 1-4 Category I (not contaminated material) 39% of overall mass

Category II (suspected material) 59% of overall mass

Category III (contaminated material) 02% of overall mass

Material to be stored/disposed as radioactive wastes About 0.5% of the overall mass (ca. 250 Mg)

Averaged dismantling duration for a twin unit: about 4 years

1 year dismantling and

3 years cutting

General facts on turbine hall dismantling

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Turbine hall dismantling - resources, capacities and costs

Averaged annual staff requirements (1996 – 2007)

44 EWN Staff (on site work organisation, dismantling, cutting, transport)

And 6 workers from external companies

Averaged productivity (1996 – 2007)

50 kg/man-hour (dismantling and cutting)

This results in (for the turbine halls 1- 6 and remaining supervised

area):

1.1 million man-hours (including planning, overheads, etc.)

51.5 million € (including planning, overheads, etc.)

● Personnel cost: 46.8 million € (91%)

● Direct cost: 4.7 million € (09%).

General facts on turbine hall dismantling

6 EWN – training for manual dismantling

EWN training for manual dismantling

Dismantling of units 7 and 8 (clean, 80% completed)

Performed between 1991 and 1994

Can be regarded as “full scale testing”

(no radiological limitations)

Testing of different cutting tools

(mechanical, thermal)

Applicability for different

material and thicknesses

Advantages/ Disadvantages

(e.g. space requirements,

speed, dust creation,

reliability/ safety, auxiliaries)

Involved staff: former maintenance

and technical (operational) staff

Qualification: on the job



Prerequisites/ preconditions:

Available technical staff with knowledge

from operation/maintenance

“Full scale testing area”

“No restrictions” for selection of tools

Results:

Real dismantling work performed

Staff with confidence, experiences, skills

Choice of tested dismantling tools

readily available on the market

List of applicable tools and their areas

of application (part of dismantling instruction)

There was no requirement (by the authority)

to proof “special” staff qualification for manual

dismantling

(there is a sufficient degree of trust)



Staff training/ adaptive qualification for decommissioning

Company specific adaptive qualification performed internally by several

Departments (for 43 workers from Greifswald and Rheinsberg NPPs in 1994)

Three weeks theory - lectures/ seminars (Bolded items - with examination): EWN disposal concept (project structure, residual material managem., licensing)

Health, labour and fire protection

Radiation protection (Basics, access regime, zoning concept, personal dosim.)

Environmental protection (Legal basis, hazardous wastes, material handling)

Decontamination (Basics, decontamination procedures/processes, experiences)

Cutting procedures (shearing, sawing, grinding, thermal cutting, plasma

cutting)

Waste management (Waste streams and treatment facilities, storage and

disposal)

Transport and lifting equipment and fittings

One week practical exercises Operation of transport/lifting devices, measurement devices for rad. protection

First aid practise, operation of manual fire extinguishers



Staff training/ adaptive qualification for decommissioning

Company specific adaptive qualification performed internally by several

Departments (for 43 workers from Greifswald and Rheinsberg NPPs in 1994)

Results:

(Internally) certified specialised staff:

Operators of ground based transport/ lifting devices, Riggers and

Executioners

Thermal/ plasma cutter

First-aider

Staff prepared for further external qualification/examination

E.g. decontamination worker


Training results: Principle dismantling technologies

Mech. cutting techniques for steel, non-ferrous metals, plastics (examples)

Devices/techniques Application range

Hand operated sawing techniques

1. Band saw with pneumatic or electric drive 120 mm

2. Reciprocating saw (sword saw) 130 mm

3. Reciprocating saw (jig saw) with clamping & feed device 440 mm

4. Small sized metal saw with electrical drive 34 mm

Portable working tools for pipes and vessels

1. Tube cutter with electrical drive Up to Ø 25 mm x 1 mm

2. Tube saw with pneumatic drive Up to 40 mm depth

3. Tube cutter fixed externally on the tube with hydraulic drive Ø 152 mm - 622 mm

4. Tube milling machine with pneumatic drive Ø 1515 mm, 45 mm depth

Hand operated shears for tubes and vessels

1. Shears with electrical drive (nibblers) High alloyed steel up to

5 mm, others up to 10 mm

Stationary working tools for tubes and sectional steel (profile steel)

1. Hydraulic shears Sectional steel up to 50 mm


Training results: Principle dismantling technologies

Thermal cutting techniques for different materials (examples)

Devices/techniques Material Application range

Oxyacetylene cutting

1. Oxygen cutter (machine & manual) C-steel Up to 300 mm

Plasma cutting

1. Manual and machine driven cutters S-steel, Al Up to 75 mm

2. Machine driven cutter with media:

compressed air, H2, O2, N2, argon

High alloyed steel Up to 80 mm under water

Powder injection flame cutting

1. Powder injection flame cutting S-&C-steel, cast iron Up to 300 mm

Thermic lance

1. Thermic lance (Core lance) Different materials Up to 2000 mm

Laser cutter

1. Manual and machine driven cutters

with compressed air

S-steel, C-Steel Up to 10 mm

Contact arc metal cutting

1.Manipulator driven cutting device conductive materials Limited by current and

electrodes dimensions

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Licensing - Overview

Licensing procedure integrated in the general staged

approach

Different parts of the TH are covered by different

part licenses, e.g: G01.1 (Dismantling in supervised area units 1 to 6)

G03 (Dismantling controlled area units 1 and 2)

G04 (Dismantling controlled area units 3 and 4)

G06.3/4 (Dismantling of remaining buildings and

systems)

Mainly stepwise application and realisation as

reserve/alternative to dismantling in the controlled

area TH5/6 about 60 PCDs

TH3/4 and TH 1/2 about 10 PCDs

OVERALL LICENCE

G01 (30. June 1995)

Part licence

(e.g. G03, G04) Part licence

(e.g. G03, G04) Part licence

(e.g. G03, G04)

PCD-0 PCD-1

PCD-2

Dismantling instructions

EWN licensing/ planning approach

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General licensing/ planning approach

Results (in view of dismantling)

We have PCD 0, 1, 2

A general framework established with the overall licence (general rules,

applicable methods and technologies, overall safety report)

An approved scope for decommissioning (dismantling scope)

A general description of work

Defined links with licensing authority (authorized experts) for controls

General timeframe

We have (internal) dismantling instructions

A detailed and binding

sequence of work if necessary

A concrete association of

materials and technologies

in exceptional cases only

Subject of detailed planning

(no need for approval)

EWN licensing/ planning approach

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Main strategies for planning

Shut down and separation of systems

System by system (controlled area: same approach)

Dismantling planning and realization

Unit by unit (controlled area: room by room)

Subdivision into sections based on physical location and accessibility e.g.

Generator-transformer unit

Turbine and condenser

Big vessels (pre-heaters, feed water tanks)

Small technological equipment (small pipes, pumps, drives, valves, …) top down

Steel constructions (supports, stages, stairs)

I&C equipment

Building structures (concrete parts)

EWN Dismantling planning

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Main strategies for material categories

Category III materials (contaminated materials)

Dismantling into as big as possible parts (under control area conditions)

Sorting, packaging and transport to ZLN or ZAW (centralized treatment places for contaminated materials)

Category II materials (suspected materials)

Dismantling into dimension of boxes

Use of centralized storage/cutting places in the turbine hall

Packaging and transport to free release measurement facility

Category I materials (non-contaminated materials)

Dismantling into as big as possible parts

Use of centralized storage/cutting places in and outside the machine hall

Conventional removal/release of materials


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Main dismantling strategies

Dismantling technologies Use of maintenance and repair procedures as basis for dismantling

instructions

Cutting points = assembling connections (e.g. flanges) -> results in e.g. 3 m long pipe sections for lifting with cranes

Cutting of bolts instead of unscrewing if possible, cutting of equipment

Centralized cutting places = main working places Usage of “free” space between the units (former repair/maintenance and

storage areas)

Dismantling into as big as possible parts: Depends on suitability and availability of lifting and transport equipment

E.g. complete components (tanks, vessels) to be lifted by cranes

Depends on type of equipment to be dismantled Tubes up to Ø 50 mm and connected equipment: general cutting to dimensions

and weight suitable for manual transports


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Detailed planning and boundary conditions

Availability of lifting and transport capacities

Turbine hall cranes for big components

Transport ways, openings

Transport means (trailers)

Accessibility of equipment to be dismantled

Work load of cutting places and storage capacities

Availability of material management equipment

Free release capacities

Availability of work force

Parallel work in different units


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Detailed planning and boundary conditions

Approach implemented up to about September 2006

Dismantling focuses on controlled area

Dismantling in the turbine hall depends on available (remaining) resources

“New” approach since about September 2006

New aim:

To empty the turbine hall as soon as possible and to prepare the turbine hall for reuse

Consequences

Installation of storage places outside the turbine hall for Cat. I and II materials in the controlled areas of unit 5 to 1 and “open air”

Removal of bigger parts for storage

Additional transports outside the turbine hall

Complete disconnection of dismantling from cutting


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Centralised cutting places

Cutting place with band saw

Dismantling of the turbine hall – practical work

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Centralised cutting places

Manual cutting at cutting pace


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New storage places

Storage places in controlled areas of units 5 - 1


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New storage places

Open air storage of turbine hall equipment (Nov. 2006)


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Big component dismantling

Removal of main generator stator


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Dismantling of a turbine – steam pipes


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Dismantling of turbine components


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Dismantling of a turbine condenser


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Dismantling of a turbine condenser


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Dismantling of a feed water tank


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Dismantling of complete vessels


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Dismantling of smaller parts

Dismantling or remaining equipment top down


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Dismantling of smaller parts

Removal of cable trays - fire protection containing

asbestos


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Concrete demolition

Demolition of turbine desk


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Concrete demolition

Demolition of turbine desk


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Concrete demolition


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Concrete demolition

Demolition of concrete floor (channel cutting)


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Concrete demolition

Preparation of new wall openings (doors)


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Concrete demolition

Removal of building structures


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Concrete demolition

Removal of building structures


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Recreation of the floor for reuse


Documents

Dismantling of the turbine hall at Greifswald NPP · “Dismantling of the turbine hall at Greifswald NPP” ... Tube milling machine with pneumatic drive Ø ... C-Steel Up to 10