Fire Protection Program Of Chashma Nuclear Power Generating Station Pakistan Atomic Energy Commission

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Nuclear Power in Pakistan

Nuclear Power

Plants

Capacity

(MWe)

Year of

Commissioning

In Operation

KANUPP (PHWR) 137/90 1972

CHASNUPP-1 (PWR) 325 2000

CHASNUPP-2 (PWR) 325 2011

Under-construction

CHASNUPP-3 (PWR) 340 2016

CHASNUPP-4 (PWR) 340 2017

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Location of NPPs

3

KANUPP

IRA

N

TAJIKISTAN CHINA

C1/C2/C3/C4

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Plants Design / Specifications of CNPGS

Reactor Type PWR, 2 Loop

Rated Thermal Power 998.6 MWth

Gross Electrical Output 325 MWe

Net Electrical Output 300 MWe

Operating Pressure 15.2 MPa

Operating Temperature 280-302 oC

Net Efficiency ~34 %

4

Elements of Fire Protection Program

• Design Codes and Standards

• Principles of Fire Protection

• Fire protection policy

• Fire Fighting Strategy

• Manual Fire Fighting

• Fire Prevention plan

• IAEA Expert Review Missions

• Fire Events Review at CNPGS

• On-going Issues

• Improvement plan

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Principles of Fire Protection

Defense in Depth criteria will ensure throughout plant lifetime following objectives:

• Preventing fires from starting

• Detecting and Extinguishing quickly those fires which do starts, thus limiting the damage

• Preventing the spread of fires which have not been extinguished, thus minimizing their effects on essential plant functions

• Ensuring that fire will not prevent the performance of necessary plant safe shut down functions and will not significantly increase radioactive release to the environment

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Fire Protection Policy

Protection of Structures, Systems & Components

Fire prevention • Use of non combustible material in construction and

non combustible /fire resistant equipments / cables • Transient Combustible Control • Control of Ignition Source Fire Detection • Provision of State of the Art Plant Fire Detection and

Alarm system Fire fighting Systems • A combination of Auto Actuated and Manual Fire

Fighting Systems

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Fire Protection Policy ----------

Preventing the Spread of Fire • 03 hours & 1.5 hours fire resistance rating fire

compartment • Redundant trains of safety systems • Spatial separation of safety equipment • Fire retardant Class 1E Electrical cables and

Equipment • Fire dampers in HVAC Ducts • Implementation of Fire Barrier penetration seals

Procedure • Smoke Exhaust system for important plant areas

(MCR, 6 kV panel rooms)

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Fire Fighting Strategy

Fire Water Suppression systems includes: Four 50% capacity fire water supply pumps Two 100% Fire Water Pools Independent pneumatic pressurizer pumps & tanks Pressurized fire water main supplies to Spray & Sprinkler

System, pre-action deluge system and fire hydrants Auto actuated Deluge valve protect cable shafts, cable

spreading areas, Charging pumps, lube oil tanks, Turbine Generator bearings and main transformers.

Fixed CO2 fire extinguishing system protect Emergency Diesel Generators and Auxiliary feed water Diesel Driven Pumps & tanks in Nuclear Auxiliary building

Fixed foam system protect Diesel fuel oil tanks at EDG building

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Manual Fire Fighting

• Fire hydrants covers all areas inside and outside the plant buildings

• More than 1400 portable fire extinguishers at about 400 fire points

• Plant operation staff trained in fire fighting serve as first responder to fire in plant

• Plant on-site Fire Brigade is equipped with 4 Fire Tenders, more than 40 professional fire fighting staff and equipment

• Perform Round the Clock shift duty • Equipment in Fire Tenders - hose pipes, Multi-jet Nozzles,

Special Safety Shoes, Fire Resistant Suits, Fire Helmets, Emergency Communication equipment, Flash Lights, Self Contained Breathing Apparatus, CO filters, Full Face Masks, Fire Extinguishers etc.

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Fire Prevention Plan

• Conduct of Transient Combustible Control inspection every month

• Control of ignition sources through administrative procedures

• Control of Hot work through work permit /fire watch

• Conduct of Fire drills regularly to verify the preparedness of operator and fire fighting staff

• Imparted training in fire fighting to other plant personnel

• Close collaboration with off site fire brigade

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Fire Prevention plan

• Emergency plans are available for the proper response to all potential site fires, particularly nuclear safety-related areas and equipment.

• Plans contains safety-related areas and equipment layout, fire hazards, fire protection equipment and fire detector type and location

• Respond to fire alarms • Notification to emergency response teams (e.g., on-

site fire brigade, off-site fire department) • Coordination with operations and security personnel • Fire-fighting techniques • Response to potential radiological hazards.

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IAEA Fire Protection Mission to C-1

• IAEA Pre OSART Review Mission of Chashma NPP Unit-1 was conducted in 1999 and recommended Review Mission on Fire Protection.

• IAEA Experts Review Mission on Fire Protection of Chashma NPP Unit-1 was conducted from 8 to 12 Nov 1999 prior to initial core loading.

• Overall fire protection program in the light of FSAR and FHA was reviewed.

• 12 Recommendations and 17 Observations were recommended in the mission final report

• Mission’s recommendations and observations were implemented in due time and made the fire protection requirements at par with FSAR and FHA

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IAEA Fire Training Follow-up Mission

• IAEA Experts Fire Training Mission from 11 to 14 April 2000 was conducted at Chashma NPP Unit-1.

• 40 participants from Operation, Maintenance, Health Physics & Technical Divisions participated.

• Various plant fire protection procedures were developed as result of the training mission.

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IAEA OSART Mission

• IAEA OSART Review Mission on Unit-1 was conducted in 2004

• Mission gave 3 recommendations on Fire protection program

• Resolution of issues were verified during OSART follow-up mission in 2006.

• FHA was reviewed and validated during PSR conducted in 2010

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Fire Events Review at CNPGS

# Description Causes Corrective Action 1. Plant was in Mode B after fuel loading.

On 18.06.2004, under-water lights

were switched ON to perform some

work. These lights were left “ON”

inadvertently. On 19.06.2004 water

from spent fuel pool was transferred

to FTC for some requirement. When

water level decreased below set point,

level switches of under-water lights

switched off their respective lights

except one due to malfunction of its

level switch. A short circuit in the

underwater light resulted in damage of

the power cable insulation which

resulted in the burning of 10 under

water light cables, 07 floating switches

cable, 03 under water light controllers,

under water light camera cable.

Direct Cause: Malfunction of the water level switch (controller) of an under water light and power supply circuit breaker. Root Cause: In-adequate work control and non existence of a procedure defining responsibilities of the operators /work Group for operation of underwater lights. Contributory Causes: In-adequate procedure for draining water from the spent fuel pools. Use of a single circuit breaker for two underwater lights.

Incorporated instruction in the relevant procedure for the circuit breakers of all under water lights are to be switched off prior to start of draining water from the pools. Modified existing power supply circuit for the underwater lights so that each light has its own breaker of 6 Amps instead of a common 16 Amps for two.

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Fire Events Review at CNPGS # Description Causes Corrective Action

2. On 25-02-2008, smoke alarm

received in MCR from room NA

004. On surveillance by

operator smoke / burning smell

was observed from Incoming

Breaker-B of MCC Panel.

Loose joint of terminal of one phase of a power supply bus to the breaker caused heating of insulating material. No real fire develop.

Terminal joints were replaced and were properly tightened.

3. On 26-9-2011, Plant was at

mode 4A. SRC heating and

pressurization was in progress

with RCP-B in operation.

Operator observed smoke

coming from near pump body.

Fire alarms also gave fire alarm.

MCR was informed and pump

was stopped

Soaked oil in insulation material ignited due to high temperature of SRC line i.e. 192ºC

Pump was stopped. Fire was extinguished using portable fire extinguishers. Insulation was removed and leakage of oil was fixed.

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Fire Events Review at CNPGS

# Description Causes Corrective Action

On 20-3-2014 when plant was operating at full load smoke alarm annunciated in MCR from IPB (Insulated Phase Bus Bar) area at +8.0 m, underneath Main Generator at turbine building. Whereas after checking the area smoke and sparking was observed from carbon brushes of Main Generator. GCB was manually opened and reactor was manually tripped

Direct Cause Smoke due to sparking from carbon brushes Contributory Causes Choking of the slanted ventilating holes of slip ring . Choking of ventilation ducts of carbon brush assembly. Root Cause Design inadequacy preventing effective monitoring of carbon brushes.

- Replaced and repaired damaged parts. - Adjusted gaps between the slip rings and carbon brushes holders in the range of 1.5 mm to 3.5 mm as per vendor advice. - Cleaned ventilating holes of slip rings and inlet / outlet ventilation duct of carbon bushes assembly. - Marked the individual carbon brush holders in the carbon brush rigging. - Installed smoke detectors in generator cubical

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On Going Issues

• Obsolete electronic of Plant Fire Detection and Alarm System

• Maintenance issue of pneumatic fire detection piping net of Main, Auxiliary and Step down transformers

• Non availability of power supply to Fire alarm control panel under LOP / draining of back up battery.

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Improvement Plan of Fire Detection System Unit-1

• Components and software of plant Fire Detection and alarm system are being upgraded – in progress

• Transformer’s pneumatic detection is being replaced with Automatic flame detectors – will be done in RFO-10

• To provide connection from emergency power supply to fire alarm control panels in MCR –modification is under review

• Air sampling fire detectors are being installed inside electrical cabinets in NI – will be done in RFO-10

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Any Question Please

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