Technical aspects of improving

acceptance of nuclear power

: dealing with catastrophe syndrome

Anil Kakodkar*INSAC 2012

November 7,2012*With inputs from Shri H. S. Kushwaha & Dr. R. K. Singh

Key issues in public acceptance• Dealing with mind sets Small is beautiful Nuclear is evil Perceived external influence Trust deficit , NIMBY………• Catastrophe syndrome Consequences (real or perceived) larger than a threshold are unacceptable regardless of low probability TMI, Chernobyl and now Fukushima have created adverse impact on public mind That Fukushima was caused by nature’s fury is an added factor

NEVER AGAIN• Both TMI & Chernobyl were triggered by internally initiated

events

• Several lessons learnt, improvements implemented and confidence restored

• Signs of nuclear renaissance were visible

• Chernobyl also led to valuable insights into consequences in public domain

• Fukushima was triggered by an extreme external natural event

• We must now ensure that an essential goal for nuclear safety is “NEVER AGAIN” should there be any significant off site emergency

Comprehensive approach to safety1. Reassess the design basis assumptions for both new and existing

plants at two levels• plant shall be able to cope without significant radioactive releases and without irreparable damage • plant should be able to cope without requiring significant off-site emergency response

2. Reassess plant response to severe accidents that cause extensive reactor damage

3. Develop and implement effective on-site accident management strategies

4. Reassess capabilities for off-site emergency management5. Approach to old and new nuclear power plants6. Reassess safety culture and quality of safety management7. Ways to strengthen the international safety regime8. Better ways to inform the media and the public on the severity of an

accident are needed.

Dual level design basis• Design basis No impact in

(risk lowered to an public domain or acceptable level) irreparable damage to plant

• Extreme event* No significant off-site

(maximum potential) emergency

*Extra margin between design and ultimate load capacity should be sufficient to cope with this

• Note: Nuclear Power Plants are Designed to withstand the loading due to Natural and Man-induced external Events with low enough probability of occurrence. Some of the man induced hazard are ruled out using SDV Criteria.

• On a similar logic one could identify maximum potential loading for specific engineered safety features / events at a site* and demonstrate them to be within the margin beyond design basis capacity.

• *Core cooling capability, hydrogen mitigation, containment isolation, earthquakes, tsunami, etc.etc.

Potential Natural and Man-Induced Hazard Phenomena

 

• ATOMOSPHERIC Cyclones Tornado Tropical Storm Lightening

• SEISMIC Ground Shaking / Fault Rupture Liquefaction Tsunami • GEOLOGICAL Rock Fall Land Slide Debris Avalanches

• HYDROLOGICAL Flooding

Strom Surge Erosion and Sedimentation

• Man-Induced Events Oil Storage & Refineries Explosion Missiles Air Craft Crash Terrorist Attack Cyber - Attack

An overview of Sensors & Instrumentation Cable for concrete, rebar and tendons

Phase-II Test- Typical Response Pre-Test Predictions by Round Robin Participants

BARC Containment (BARCOM) Test-Model (Design Pressure Pd 0.1413 MPa)at BARC-Tarapur Test Facility with details of Embedded Sensors and Cable Panels

     Jason-1 track 109 satellite (altitude 1300km) record and TSUSOL Predictions

3.99

6.00

2.833.46 3.5

-0.61

1.40

-1.77-1.14 -1.1

4.6

-3-2

-10

12

34

56

7

Prediction 4.6 3.99 6.00 2.83 3.46 3.5

Deviation -0.61 1.40 -1.77 -1.14 -1.1

SRI IGCAR IIT-M ICMAM NGRI ACRi

5.155.72

3.88 4.00

5.74

0.651.22

-0.62 -0.50

1.24

4.5

-1

0

1

2

3

4

5

6

7

Prediction 4.5 5.15 5.72 3.88 4.00 5.74

Deviation 0.65 1.22 -0.62 -0.50 1.24

SRI IGCAR IIT-M ICMAM NGRI ACRi

• A per  capita  electricity  use  of  about 5000  kWh/year appears to be needed  for  reaching  a  state  of reasonably high    human    development. Considering  the  progressive  depletion  of  fossil  fuel reserves,  and  the  urgent  need  for  addressing  the  global warming related concerns, nuclear energy is expected to substantially  contribute  to meeting the future global energy requirements.

• Assuming that  at least half of  the  total  energy  demand  may  need  to  be  met  with nuclear,  the  world  will need  between  3000  to  4000  nuclear  power reactors of different capacities for electricity generation. The number may at least double with the use of nuclear energy  to  provide  an  alternative  to  fluid  fossil  fuels.

• A large number of these reactors may need to be located in regions with high population densities and modest technological infrastructure with their sizes consistent with local needs. 

Long term nuclear power development- The challenge of the numbers.

10

AHWR is a 300 MWe vertical pressure tube type, boiling light water cooled and heavy

water moderated reactor (An innovative configuration that can provide low risk nuclear energy using available technologies)

AHWR 300-LEU would enable realisation of these advantages with competitive Uranium use & without the need for concurrent recycle. This may be a necessity in many

countries.

AHWR can be configured to accept a range of fuel types including LEU, U-Pu , Th-Pu , LEU-Th and 233U-Th in full core

AHWR Fuel assemblyAHWR Fuel assembly

Bottom Tie Plate

Top Tie Plate

Water Tube

Displacer Rod

Fuel Pin

 Major objectives Significant fraction of energy

from Thorium

Several passive features 3 days operator grace period No radiological impact in

public domain Can address insider threat

scenarios Lower proliferation concerns

Design life of 100 years.

Easily replaceable coolant channels.

Peak clad temperature hardly rises even with the extreme postulate of complete

station blackout and simulteneous failure of both primary and secondary

shut down systems.

13

PSA calculations for AHWR indicate practically zero probability of a serious impact in public domain

Plant familiarization & identification of design aspects important to severe accident

Plant familiarization & identification of design aspects important to severe accident

PSA level-1 : Identification of significant events with large contribution to CDF

PSA level-1 : Identification of significant events with large contribution to CDF

Level-2 : Source Term (within Containment) Evaluation through Analysis

Level-2 : Source Term (within Containment) Evaluation through Analysis

Release from Containment Release from Containment

Level-3 : Atmospheric Dispersion With Consequence Analysis

Level-3 : Atmospheric Dispersion With Consequence Analysis

Level-1, 2 & 3 PSA activity block diagramLevel-1, 2 & 3 PSA activity block diagram

Variation of dose with frequency exceedence(Acceptable thyroid dose for a child is 500 mSv)

Iso-Dose for thyroid -200% RIH + wired shutdown system unavailable (Wind condition in January on

western Indian side)

Contribution to CDF

SWS: Service Water System

APWS: Active Process Water System

ECCS HDRBRK: ECCS Header Break

LLOCA: Large Break LOCA

MSLBOB: Main Steam Line Break Outside Containment

SWS63%

SLOCA15%

10-3 10-2 10-1 100

10-14

10-13

10-12

10-11

10-10

Fre

qu

ency

of

Exc

eed

ence

Thyroid Dose (Sv) at 0.5 Km

1 mSv 0.1 Sv 1.0 Sv 10 Sv

10-

14

10-

13

10-

12

10-

11

10-

10

    Generic Assessment Procedure for Determining Protective Actions during a Reactor Accident

 • Accident Assessment • Emergency Classification • Protective Action Decision Making

• Assessment of Environment Data • Monitoring • Operational Intervention Levels (OILs)

LNT Model is Inaccurate The major cause of worry is the general public perceiving that

radiation is harmful no matter how low the dose.

Reality Real radiation danger levels Crosses show the mortality of Chernobyl firefighters (numbers died/total in each dose range ) 

.Colorado ,USA has a population over (curve is for rats)5 millions residents. According to LNT model Colorado should have an excess of 200 cancer deaths per year but has a rate less than the national average. . Ramasar ,Iran, residents receive a yearly dose of between 100-260 mSv. This is several time higher than radiation level at Chernobyl and Fukushima exclusion zone. People living in Ramsar have no adverse health effect , but live longer and healthier lives. . We also know that China , Norway, Sweden, Brazil and India have similar areas where radiation level is many times higher than 2.4 mSv/yr world average.     

 

Above 4,000 mSv 27/42 died from Acute Radiation Syndrome (ARS),

not cancer.Below 4,000 mSv 1/195 died.

IN CASE OF CHERNOBYL

SOME ESTIMATED CONSEQUENCESAN ESTIMATE IN 2006—93,000 WILL DIE DUE TO CANCER UP TO THE YEAR2056 ANOTHER ESTIMATE IN 2009---985,000 DIED TILL 2004

ACTUAL CONSEQUENCETOTAL DEATHS;62 (47 PLANT, 15 DUE TO THYROID CANCER )ACUTE RADIATION SYNDROME;134 (OUT OF WHICH 28 HAVE DIED)INCREASED CANCER INCIDENCE; AMONG RECOVERY WORKERSTHYROID CANCER; (CURABLE, WAS AVOIDABLE) 6000 ( 15 HAVE DIED)

Projected health consequences from low doses to large sections of population are questionable

Driven by over conservative linear

no threshold principle (which is not substantiated by surveys in high natural radiation

background areas) we tend to create

avoidable trauma in public mind

Looking back at Fukushima

. It has become apparent at Fukushima that the evacuation from the “exclusion Zone” has been excessive. Some of the areas that have been evacuated probably suffered so little contamination that they could be reoccupied. . As per WHO report most of the people in Fukushima prefecture would have received a radiation dose of between 1-10 mSv during first year. Two places the dose were between 10- 50 mSv still below harmful level. Almost all other places were below the internationally agreed reference level for the public exposure due to radon in dwelling (about 10 mSv).

Chernobyl Psychosomatic effects

‘Besides the 28 fatalities among rescue workers and employees of the power station due to very

high doses of radiation (2.9 - 16 Gy), and three deaths due to other reasons (UNSCEAR 2000b),

the only real adverse health consequences of the Chernobyl catastrophe among approximately

five million people living in the contaminated regions were the epidemics of psychosomatic

afflictions. These appear as diseases of the digestive and circulatory systems and other post-

traumatic stress disorders such as sleep disturbance, headache, depression, anxiety, escapism,

“learned helplessness”, unwillingness to cooperate, overdependence, alcohol and drug abuse

and suicides (Forum 2005). These diseases and disturbances could not have been due to the

minute irradiation doses from the Chernobyl fallout (average dose rate of about 1 - 2

mSv/year), but they were caused by radiophobia (a deliberately induced fear of radiation)

aggravated by wrongheaded administrative decisions and even, paradoxically, by increased

medical attention which leads to diagnosis of subclinical changes that persistently hold the

attention of the patient.

Bad administrative decisions made several million people believe that they were “victims of

Chernobyl” although the average annual dose they received from “Chernobyl” radiation was

only about one third of the average natural dose. This was the main factor responsible for the

economic losses caused by the Chernobyl catastrophe, estimated to have reached $148 billion

by 2000 for the Ukraine, and to reach $235 billion by 2016 for Belarus.’ ---- Zbigniew Jaworowski, “The Chernobyl Disaster And How It Has Been Understood” WNA personal perspectives

. The Health Physics Society's position Statement first adopted in Jan. 1996, as revised in July 2010, states: In accordance with current knowledge of radiation risks, the Health Physics Society recommend against quantitative estimation of health risks below an individual dose of 5 rem(50 mSv) in one year or a lifetime dose of 10 rem (100 mSv) above that received from natural sources.

. French Academy of Sciences and the National Academy of Medicine published a report in 2005 that rejected the LNT model in favour of a threshold dose response and a significantly reduced risk at low radiation exposures.

What do we need to do?

• Realistic worst case assessment in public domain at each site taking margins beyond design basis into account

• Pragmatic evidence based intervention levels ( not biased by LNT) to be articulated in advance

• Credibly demonstrate best estimate impact in public domain (expected to be much lower)

• Develop and deploy systems that do not cause any adverse impact in public domain

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