IAEA “TECHNICAL MEETING ON THE USER-VENDOR

INTERFACE IN COGENERATION FOR ELECTRICITY PRODUCTION AND SEAWATER DESALINATION”

VIENNA

(14-16 MARCH, 2016)

KANUPP

USER OF COGENERATION PLANT AT KANUPP &

EXCHANGE OF OPERATING EXPERIENCE FEEDBACK AND DESIGN OF COGENERATION PLANT

KANUPP

Ahsan Ullah Khan Principal Engineer

CONTENTS

1. NPP in Pakistan 2. Cogeneration Plant at KANUPP 3. Design Basis & Operational Data 4. Coupling Scheme 5. NDDP Water Cost using DEEP 6. Major Advantages 7. Challenges Faced/Major Limitations 8. Refurbishment and Localization at NDDP 9. Integration of RO with thermal Desalination Plant 10. Future Status 11. Conclusion

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1. NPP in Pakistan

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KANUPP C-1 C-2

Location Karachi Chasma Chasma

Type PHWR PWR PWR

Capacity 137MW 325 MW 325 MW

Start of Construction 1966 1993 2005

Commercial Operation Dec 1972 Sep 2000 May 2011

Nuclear Power Plants in Operation

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C-3 C-4 K-2 K-3

Location Chasma Chasma Karachi Karachi

Type PWR PWR PWR PWR

Capacity 340 MW 340 MW 1120 MW 1120 MW

Start of Construction 2010 2011 2013 2014

Commercial Operation Dec 2016 Oct 2017 2020 2021

Nuclear Power Plants under construction

1. NPP in Pakistan (Cont.)

2. Cogeneration Plant at KANUPP,NDDP

1600 m3/day MED Nuclear Desalination Demonstration Plant coupled with KANUPP(137MWe CANDU Reactor) commissioned in December, 2009.

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First Phase: MED : one-third capacity, first battery (1600 m3/day) ICL & Sea water intake circuits: Full capacity Second Phase: Second battery of MED plant (1600 m3/day) to be added(Locally designed and manufactured)

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2. Cogeneration Plant at KANUPP,NDDP (Cont.)

3. Design Basis and Operational Data

Design developed for co-generation of electricity and potable water

Calculation based on the basis of NPP operating at 85 MW(e) L-H-L Concept of Pressure Reversal adopted by design of Inter

Mediate Coupling Loop (ICL Loop) Use of existing COW-HX3 Exchanger as pressure reversal heat

transformer unit

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Extraction Steam from NPP Turbine is utilized for desalination. Pressurized Intermediate Coupling Loop (ICL) is used for Integration with NPP. Extracted Steam Conditions:

Flow Rate : 34.09 t/hr

Pressure : 1.71 bar

Temperature : 115.8 °C

Dryness : 74.18 %

Thermal Power (Used): 16.45 MWth

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3. Design Basis and Operational Data (Cont.)

Type: LT-HT-MED Coupled with KANUPP

Vendor ASTER, GILAF Group, Italy

NPP Type 137 MWe PHWR, CANDU (433 MWth)

Distillate Production:

Net Production: 66.7 t/h

Temperature: 40 0C

TDS (Product Water): <10 ppm

TDS (Potable Water): < 300 ppm

GOR 6.2 : 1

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3. Design Basis and Operational Data (Cont.)

Steam Condition at Re-boiler

Secondary Steam 26.7 t/hr

Pressure 0.385 bar (a)

Temperature 75 0C

Quality 95 %

Total Consumption 11.1 t/h

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Seawater Inlet

Total Consumption 493 t / h

Inlet Pressure 5 bar (g)

Temperature 27 0C

TDS 40,000ppm

of NDDP

3. Design Basis and Operational Data (Cont.)

4. Coupling Scheme

Safety approach through Intermediate Coupling Loop (ICL) System

Totally closed isolation loop with a pressurizer function

Pressure of the hot water on tube side is greater than the shell side steam to avoid any risk of contamination

The loss of pressure in the IL loop automatically cuts off the steam supply from the turbine

Through ICL loop, a dynamic barrier obtained to prevent potential carry-over of radioactivity

Minimum design changes in the existing NPP piping layout

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Coupling Scheme of NDDP got reviewed by third party, ITALIAN Company

International assistance through International Atomic Energy

Commission (IAEA) remained available

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4. Coupling Scheme (cont.)

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5. NDDP water cost applying IAEA developed Toolkit DEEP5

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DEEP RESULT ACTUAL VALUES

COMMERCIAL

0.28 Rs/liter (2.74$/m³)

0.22 Rs/liter (2.19$/m³)

0.52 Rs/liter (5.26$/m³)

6. Major Advantages

Cost Saving Product water cost is HALF of commercial water cost.

Reduced Load on Water Treatment Plant WTP re-generation time increased FIVE times.

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6. Major Advantages (cont.)

Reduced Environmental Discharge of Chemicals Chemicals discharge reduced by a factor of FIVE.

More Secure/Reliable Source Physical security threat reduced. Worse law & order situation.

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6. Major Advantages (cont.)

Indigenization NDDP equipment manufactured, installed &

commissioned locally. Reduced technical uncertainties. Enhanced public interest and confidence.

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7. Challenges Faced/Issues

Loss of Production: Scale formation on external surfaces of Evaporator tubes, Gained Output Ratio lowered. The acid cleaning operation needs to be carried out every year

Enhances safety of coupling:

Multiple safety barriers must be provided in inherent design in order to achieve contamination free water At KANUPP, pressurized secondary loop and a steam loop incorporated b/w the nuclear reactor and MED process as a safety barrier.

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Tube Leakages :

Leakage on exchanger tubes of Re-boiler and Distillate Condenser

Vendor Support

Effective Vendor support remained unavailable on technical issues

Hurdles in commercial sale :

Low availability factor of KANUPP

High transport cost

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7. Challenges Faced/Issues (Cont.)

8. Refurbishment and Localization

Replacement of Re-boiler tube bundle:

Due to gradual increase in leakage of re-boiler tubes , the whole tube bundle replaced with new one. The tube bundle was manufactured locally.

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Water Box Modification:

The water box side of re-boiler provided with flanged arrangement for one to one replacement of tube bundle in future(maintenance time reduced)

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8. Refurbishment and Localization (Cont.)

MED Evaporators:

Gaskets of Evaporators Vessel gates replaced (8 Nos). As a result quality of product water improved and design value of product water(10-20 µ S/cm) achieved again.

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8. Refurbishment and Localization (Cont.)

Modification:

Scheme for dual operation of feed heater(COW-HX3) incorporated Minimum losses to the efficiency of NPP secondary cycle Chemical injection system at re-boiler shell side to maintain PH. Facility of N2 gas blanketing provided to Re-boiler tube bundle

(1132 tubes) to keep it preserved in case of long shut down.

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8. Refurbishment and Localization (Cont.)

Various stages of NDDP equipment manufacturing at PAEC workshop

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Various stages of NDDP equipment manufacturing at PAEC workshop (Cont.)

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Various stages of NDDP equipment manufacturing at PAEC workshop (Cont.)

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9. Integration of RO with thermal Desalination Plant

Setting up 03 units of SWRO ( 3*1900 m3/day)

First unit 950 m3/day commissioned Oct 2015. Total water requirement at site = 8800 m3/day. Current installed capacity = 3000 m3/day. which is 65% less than requirement.

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Seawater supply to RO from discharge of NDDP is estimated at 1000 m3/h.

All desalination units share one seawater intake system and one brine outfall system.

Product of RO to be blended with MED plant product to reduce re-mineralization cost.

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9. Integration of RO with thermal Desalination Plant (Cont.)

PRODUCT

3 67 m /hr

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TO SEA28 m /hr

TO EVAPORATORS3232 m /hr

3800 m /hr3TO MED472m /hr

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TO SEA 293m /hr

TO SEABRINE REJECT

3165m /hr

PRE - HEATERS

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MED PLANT

8 EFFECTS (TOTAL)EVAPORATORS

FINALCOND.

DUMP CONDENSER

POSTTREATMENT

GRIDWATER

3 INTAKE PUMP1300 m /hr

SEA WATER

(SCHEMATIC DIAGRAM OF PROPOSED INTEGRATION OF HT-RO WITH THERMAL DESALINATION PLANT) Figure 2. KANUPP NUCLEAR DESALINATION DEMONSTRATION PLANT

3800 m /hr

240 m /hr3

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TO EJECTOR28 m /hr

WATER EJECTOR

TO HT - RO1040 m /hr3

PRODUCT400 m /hr3

HT - RO

TO SEAREJECT

9. Integration of RO with thermal Desalination Plant (Cont.)

Type DAF-UF-RO

Commissioned Oct, 2015

Capacity 950 m3/day (0.25 MGD)

Total Dissolved Solid(product water) Less than 500 ppm

Net Recovery 40 %

Raw feed water to UF 135 m3/hour( MED cooling waste)

Permeate flow 40 m3/hour

Reject flow 60 m3/hour

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10. Future Status

Potential for deploying Nuclear Desalination Plant may be feasible for upcoming Karachi coastal projects (2×1100 MWe each ,PWR, study required)

Installation of 3 more SWRO(3*1900 m3/day) plants in progress, raw water supply from waste heat of NDDP discharge.

NDDP second battery most feasible for satisfying the huge water demand

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11. Conclusion

Safe operation of KANUPP NDDP may be used as an evidence regarding technical viability for coupling desalination with Nuclear Power Plant

Annual Per Capita water availability in Pakistan is decreasing at very alarming rate. It was 1672 m3 in 1990 and it is forecasted that it will be 837 m3 in 2025. Below 1000 m3 chronic water stress is experienced

For large scale desalination, only nuclear energy is competitive

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KANUPP has valuable experience and trained man powers.

Use of waste heat or low grade heat from NPP are another attraction to be utilized for low temperature desalination application. IAEA ongoing CRP with member states could be handy in this regard.

IAEA developed toolkit DEEP may be valuable in economic evaluation for integrating desalination with NPP.

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11. Conclusion (Cont.)

A future desalination strategy, based on the utilisation of fossil fuelled systems is not sustainable because of the considerable amounts of GHG rejected. At the moment, the only solutions would appear to be nuclear energy and wind energy.

Where achievable, Designer / Vendor of Nuclear Power Plant may be encouraged to explore the possibility of integrating desalination plant in the base design

To ensure effective localization and integration of ND Users and Vendors may be provided more opportunities to discuss issues related to future nuclear cogeneration plants.

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11. Conclusion (Cont.)

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Thank You for your patience

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