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Green and Safe Nuclear Power

H.S. KushwahaFormer Director

Health, Safety And Environment GroupBhabha Atomic Research CentreTrombay, Mumbai- 400 085

E-mail: kushwaha746@gmail.com

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• Energy is the Basic Component for Development of Industry, Public Service and Transport

• Increased Consumption of Electric Power is Linked With Economic Development

• Increased Generation of Electric Power may Increase Emission of Pollutants to the Environment

• There is a Need to Balance between Economic Development and Environmental Degradation

• To Meet the Power Challenges in our Country all forms of Commercially Viable Sources of Electricity Generation Need to be Explored

ELECTRICAL ENERGY

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ENERGY

ECONOMICS ENVIRONMENT

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At Present India‘s Per Capita Consumption of Energy is About 600 KWH in Comparison to the Developed Countries Like USA Where It is about 12,000 KWH.

ELECTRICITY CONSUMPTION (PER CAPITA) IN SOME OF THE COUNTRIES

S.NO. COUNTRY PER CAPITA CONSUMPTION

(KWH)

1 NORWAY 25000

2 USA 12800

3 WESTERN EUROPE

5400

4 EASTERN EUROPE 4200

5 FAR EAST 1400

6 WORLD AVERAGE 3200

7 INDIA 600

Source: Envion. Management, WEF, 1999

World Net Electricity Consumption, 2003 to 2030

WORLD ELECTRICITY GENERATING CAPACITY by FUEL TYPE, 2003-2030

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NUCLEAR POWER AND ITS CONTRIBUTIONSNuclear Power : A Sustainable Source of Energy

Provide National Pride

Improve Living Standards

Contributes to National Economic Development

Spin-offs From Nuclear Power Technology

Health care, Agriculture, Food preservation, Nuclear Desalination, Isotopes for Industry

Supports Local Communities Located Nearby the Plant to Become Most Developed Villages

Contribute to the Environment Protection

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ENVIRONMENTAL AND PERSONAL SAFETY (OPERATION OF COMMERCIAL NPPs)

Nuclear Plants Pose No Threat to Workers

No Health Hazard to the Society

No Radiological Risk to the Environment

No Deaths Have Ever Resulted From Radiation

No Significant Radiation Releases have Taken Place

By Contrast, Accidents, Injuries, Illnesses and Death Related to Other Energy Sources are Common

Public Concern with Nuclear PowerSafety of Nuclear Power Plants under severe accident condition (BDBA)

Public confidence in Nuclear Energy is seriously shaken. Chernobyl/ Fukushima

Filtered hardened containment venting system to protect the environment/publicRadioactive waste disposal

HLW is stored in deep RepositoryAccelerator driven system Incineration of minor actinides

Security of Nuclear Power PlantsProliferation and terrorismGuarding Nuclear reactors and materials from terrorists and thieves

Pollution of the environment from routine discharge of radioactivity from NPP: Fear

Anti nuclear groupsRole of media

Tohuku Earthquake, 2011

Nuclear Reactors at Fukushima

Units at Fukushima-Daiichi

Unit Capacity (MWe) Construction Start Commercial Operation

start Supplier

No.1 460 April, 1967 March, 1971 GE

No.2 784 Jan, 1969 July, 1974 GE/Toshiba

No.3 784 Aug, 1970 March, 1976 Toshiba

No.4 784 Sep, 1972 Oct, 1978 Hitachi

No.5 784 Dec, 1971 April, 1978 Toshiba

No.6 1100 May, 1973 Oct, 1979 GE/Toshiba

Total Power : 4696 MWe

Fukushima Daichi Nuclear DisasterAn Earthquake of Magnitude 9, Distance from Site 177 km, Occurred in

Tohoku Bay on March 2011 at 2.46 PMFukushima Site ( 260 km from Tokyo ) has 6 BWR designed by GE:USA Owned by TEPCO: JapanAt the Time of Earthquake, Reactor 1,2 & 3 were operating and 4,5 & 6 were Shut Down.Earthquake Triggered the Scram, automatically shutting down the reactors 1,2 &3.The Earthquake led to Station Blackout Condition (No External Electricity Available to the Plant).Nuclear Fission Reaction Stopped but Fuel Continue to release decay heat of about 6.5 % of Rector Power.Reactor Require Active Cooling for Several Days to Keep Fuel Rod Below the Meltdown Temperature.Coincidently Scram Activated Emergency Generator automatically and Reactor Cooling Begins.Magnitude 9 Earthquake Triggered Tsunami.Tsunami Arrived some 50 Minute After the Initial Earthquake.

TSUNAMI EVENT at Fukushima Daiichi Plants

The 14 meters ( 46 ft) High Tsunami Overwhelmed the Plant's Seawall ( 10 meters High).Magnitude of Earthquake and Tsunami Wave Height were more than Considered in

theDesign. The Tsunami Water flooded the rooms in Which Emergency Generator were Housed.Soon the Emergency D.G. Stop Working due to flood.The Emergency Battery System – Starts operating but ran out the next day on 12 March.The Active Cooling to Reactor Stopped and Reactor begins to heat-up and Temperature of Fuel > 900o CHot Zirconium Fuel Cladding Starts Reacting with Steam and Produces Hydrogen in the Pressure Vessel.The Steam Was Vented Out from the Pressure Vessel and Mixed with Ambient Air in the Secondary Containment.The Hydrogen Gas eventually Reaches Explosive Concentration Limits in Units 1 ,2 & 3 Reactors.Explosion Occurred in the Upper Secondary Containment Buildings in all three Reactors.Due to high Radioactive release to the Environment , 100,000 peoples had to be Evacuated from their Homes.It was a Worst Nuclear Accident since Reactors 1,2 & 3 experienced Full Core Melt Down.After Two Years of Disaster , It was Revealed that Plant is leaking Radioactive Water into Pacific Ocean.

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NARORA

440 MWe ( 2x220)

NUCLEAR POWER PLANTS IN OPERATION

RAWATBHATA740 MWe

(1x100+1x200+2x220)

KAIGA

440 MWe (2x220)

KALPAKKAM

440 MWe (2x220)

KAKRAPAR

440 MWe (2X220)TARAPUR860 MWe

(2x160 + 1x540)

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2x160 MWe BWRs

Unit #1 & 2 : Oct.. 69

Under IAEA Safeguards

TARAPUR ATOMIC POWER STATION

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1x540 MWe PHWRUnit 3 &4 Sept. 05

TARAPUR ATOMIC POWER STATION

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1x100 MWe, 1x200MWe2X220 MWe PHWRsU#1 Dec 73 U#2 April 81U#3 June 00 U#4 Dec.00U#1 & U#2 under IAEA safeguard

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2X220 MWe PHWRsU#1 Jan. 84 U#2 Mar. 86

MADRAS ATOMIC POWER STATION

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2x220 MWe PHWRsU#1 Jan 91 U#2 July 92

NARORA ATOMIC POWER STATION

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2x220 MWe PHWRsU#1 May 93 U#2 Sept. 95

KAKRAPAR ATOMIC POWER STATION

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2X220 MWe PHWRsU#1 Nov 00 U#2 Mar. 00

KAIGA ATOMIC POWER STATION

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2x220 MWe PHWRsU#3 Jan. 07 U#4 July 07

KAIGA ATOMIC POWER PROJECT

Reactors Under Construction

Total Capacity under construction 4800 MWe

PFBR (500 MWe)KK 1&2 (2x1000 MWe)

KAPP-3&4 (2x700 MWe)

RAPP-7&8 (2x700 MWe)

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NUCLEAR FUEL CYCLE

OPEN CYCLE

CLOSED CYCLE

The Spent Fuel is Treated as Waste

Spent Fuel is Reprocessed and Valuable FissileMaterials are Recovered

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STEPS OF NUCLEAR FUEL CYCLE• Mining of Uranium Ore

• Conversion of U3o8 to MagnesiumDi-urante (Yellow Cake)

• Conversion of Yellow Cake to Ammonium Di-uranateand UO2

• Fabrication of UO2 Fuel Pallets and Bundles

• Loading of Fuel Assemblies to Reactor Core

• Removal of Spent Fuel

• Reprocessing of Spent Fuel

• Recovery of Unused Valuable Fissile Materials

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Nuclear Fuel Cycle

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REACTOR SAFETY PHILOSOPHY

SafetyShut Down Reactor

Maintain theBarrierTo Limit Radioactive Release To Public

Remove Residual Heat

Confinement of Radioactive Material

Cooling of Radioactive Material

Control of Radioactivity

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DESIGN REQUIREMENT OF SAFETY SYSTEMS

• Specialized Nuclear Code : Stringent International Codes and Standards

• Seismic Qualification : Analysis and Testing

• Environmental Qualification : Testing

• Unavailability of Less Than 10-3 : Probability of system out of Service

• Fail-safe Operation : Safety System should be Fail-safe

• Online Testing Without : Functional TestingAffecting Operation

REACTOR SAFETY

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• Safe Design– Proven Technology– Defense in Depth– Quality Assurance

• Safe Operation– Qualified & Trained Operators– Proven Operating Procedures– Operating Experience Feedback– Safety Culture

• Contingency Measures– Engineered Safety Features– Emergency Operating Procedures– Emergency Preparedness

BASIC PRINCIPLES OF ENSURING SAFETY

Safety in Indian PHWRsReactor Safety

Safe Shutdown Decay Heat Removal

Containment

Systems & Features

• Fast Acting

• Independent

• Passive

(Shut off Rods, Control Rods and Poison Injection for Long term shutdown)

Systems & Features

• Active & Passive

• Backup Systems

[Emergency Core Cooling System (ECCS), Suppression Pool, Inventory in Calandria & CalandriaVault, Fire water injection into Steam Generators]

Systems & Features

• Double Containment

•Inner Containment design for Design Basis Accident (DBA) pressure

• Secondary Containment under negative pressure

•Engineered Safety Features (ESF)

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1. PELLET

2. CLADDING

3. PHT

4. PRIMARY CONTAINMENT

5. SECONDARY CONTAINMENT

6. EXCLUSION ZONE

BARRIERS

Passive core cooling by natural circulation

A

B

Elevation difference between Steam Generators (B) and Reactor Core (A) provides driving force for natural circulation of coolant known as Thermosyphoning. Through this phenomenon decay heat is removed by supplying fire water to steam generator.

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SAFETY OF OLDER PLANTS

Re-authorization Every 3 Years based on

Review of Operating Experience

Periodic Safety Review Every 9 Years

• Detailed Review of Operating Experience

• Comparison with Current Standards

• Ageing Management

Licence Extension after Design Life

(Typically 30 Years)

ZONING CONCEPT AROUND A NUCLEAR POWER STATION

1. Wind speed2. Wind Direction3. Precipitation

• EXCLUSION ZONE: 1.6KMS RADIUS

• NO HABITATION PERMITED

• STERLIZE ZONE: 5KMS RADIUS• MIGRATION AND INFLUX IS NOT

ENCOURAGED

• EMERGENCY PLANNING ZONE: 16 KMS RADIUS• MANAGEMENT PREPARED TO IMPLEMENT ALL

THE REQUIREDCOUNTERMEASURES TO PROTECT PUBLIC

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• Atomic Energy Regulatory Board (AERB) has

Established Guidelines for On-site as Well as

Off-site Emergency Plans

• Emergency Exercises are Carried Out

– Site Emergency – Once a Year

– Off-site Emergency – Once in 2 Years

• AERB Observers Witness the Exercises

• Periodic Review of Emergency Manuals

EMERGENCY PREPAREDNESS

NATURAL BACKGROUND RADIATION DOSEContribution of various radionuclides and pathways to the annual

dose from a number of natural sources of ionizing radiation

3H 14C7Be

0.01 mSv

0.3 mSv

40K

CosmogenicRadionuclides

InternalRadionuclides238U, 232/Th, 40K

1.2 mSv

Inhalation dose222Rn, 220Rn and

daughters

CosmicRadiation

0.4 mSv

Terrestrial Radiation

238U232Th 226Ra235U 0.5 mSv

Safety Assessment Principles

Radiationworker

Public

Unacceptable RiskBSL BSL

Tolerablerisk

BSO BSO

ALARA

0.02mSv1mSv

20mSv Legal Limit

BSL = Basic Safety LimitBSO = Basic Safety Objective

1mSv

Negligible Risk

Broadly acceptable region

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1.6 kmExclusion Zone

Radiation workerAverage dose - 2 mSv/yDose limit – 20 mSv/y

Margin - 10

HIGH BACKGROUND RADIATION AREA

Average dose – 10 mSv/yGlobal average – 2.4 mSv/y

mSv is a unit of radiation dose and is indicates the level of risk

40K

Members of PublicAverage dose – 0.02 mSv/y

Dose limit – 1 mSv/yMargin - 50

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Exposure to Radiation Dose Exposure to Radiation Dose –– Getting the Perspective rightGetting the Perspective right

Life threatening dose - more than 3000 mSv

Radiation illness - Passing Symptoms

No symptoms, temporary changes in blood picture (A Skyscraper)

No detectable effects (A House)

Limit for the Occupational

Worker (A Man)Limit for the

public (A Brick)

(Source: Adapted from IAEA (1997) Publication on Radiation, Health and Society - 97-05055 IAEA/PI/A56E)

If a life threatening dose (50% probability) is illustrated by the height of the Eiffel tower (over 300 meters), the dose limit for occupational workers in the nuclear industry corresponds to the height of a man (2 meters) and the limit for the public to the thickness of a brick (0.1 meters).

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• Radiation Dose to Workers are Well Within the Limits Prescribed by the Regulatory Board

• Radioactive Releases and Doses to Public are Well within the Limits

RADIATION SAFETY PERFORMANCE

AVERAGE ENVIRONMENTAL RADIATION DOSE EXCLUSION ZONE BOUNDARY

µSv

/y

22.5 55 25.7 2.13 3.77 2.42

1000

0

100

200

300

400

500

600

700

800

900

1000

TAPS

RAPS

MAPS

NAPS

KAPS

KAIGA

AERBLIM

IT

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ENVIRONMENTAL SURVEILLANCE DURINGOPERATION OF THE NUCLEAR PLANT

• Assessment of the Radiation Dose to Public

• Demonstrate The Compliance of Dose Received by Population within the Regulatory Limits

• Assessment of the Radiological Impact on the Environment

• Analyses Radionuclide Distribution and Concentration in Environmental

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CONCLUSIONS

• Nuclear Power is Safe

• No Radiation Hazards to the Public

• All Environmental Releases are Well Within the Regulatory Limits

• There is No Impact on Environment

• Power Generation Cost is Competitive

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NUCLEAR POWER ISSAFE AND GREEN