1

International Experts' Meeting on Reactor and Spent Fuel Safety in the

Light of the Accident at the Fukushima Daiichi Nuclear Power Plant

International Atomic Energy Agency, VIC; Vienna, Austria 19-22 March 2012

FOCUSING ON FUKUSHIMA-DAIICHI DEFICIENCIES….

…RATHER THAN ON GENERIC NUCLEAR SAFETY ISSUES

A.J. González, R. Navarro, F. Spano and G. Terigi (in alphabetical order)

Autoridad Regulatoria Nuclear de Argentina (Argentine Nuclear Regulatory Authority)

Av. Del Libertador 8250; (1429)Buenos Aires,Argentina+54 1163231306

2

The tragedy of Japan was also an Argentine tragedy

1883 first Japanese immigrant arrived to Argentina

1915 Japanese newspaper “Buenos Aires Shuno”

1919 Japanese Garden (orchids and cyclamen)

1953, from 17m. inhabitants, 13.657 were Japanese

Today: 32 000 Japanese are Argentineans

3

One year later it is fitting to pause for:

1. remembering the great losses suffered,

2. reflecting on the Fukushima Daiichi

accident, and

3. taking stock of the current situation.

4

Content (nuclear safety to protect people rather than NPPs)

1. Fukushima and its deficiencies

2. International response

3. Lessons being learned

4. The Argentine approach

5. Epilogue

5

1. Fukushima and its deficiencies

6

The fundamental question

Were the earthquake and tsunami the

cause of the accident at Fukushima

Daiichi? …..

or

…simply, its initiating events?

7

These were devastating natural events that triggered the accident,

…. but not its fundamental cause!

The cause shall be found in safety

deficiencies

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Deficiency 1

Underestimation of potential external events, in particular:

siting the plant close to sea level in an area known to be subject to tsunamis and,

vulnerability of the grid for earthquakes.

9

Deficiency 2

Insufficient design provisions to maintain power in any emergency situation for

cooling, instrumentation, control room habitability, lighting and communications,

In particular, to ensure a reliable supply of electricity to the emergency cooling system.

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Deficiency 3

Inadequate containment and mitigation

devices to prevent the release of

substantial amounts of radioactive

material to the environment.

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Deficiency 4

Unsafe spent fuel storage

(a particular problem for enriched uranium fuel)

12

Deficiency 5

Scarce planning and preparedness, e.g. for

accident management of various events,

accidental prolonged situations and

emergency response.

Absence of an unified technical command!

13

Deficiency 6

Insufficient regulatory control.

14

Consequence

Large quantities of radioactive materials

were released into the environment.

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2. International response

17

IAEA

The IAEA is the only organization within

the UN family with specific statutory

responsibilities in nuclear safety, namely:

establishing safety standards and

providing for their application.

Did Fukushima comply with IAEA standards?

19

IAEA response

Convened a Ministerial Conference on Nuclear Safety,

which took place in Vienna, on 20-24 June 2011.

Overall objective was:

“to strengthen nuclear safety throughout the world” [sic]

rather than identifying and correcting the specific deficiencies!

The Argentine delegation was sceptic

20

An IAEA mission to review Japan's approach for assessing safety. Strengthen IAEA peer review services. A report highlighting the results of the IRRS missions. Coordination and cooperation between the IAEA and WANO; 4 OSART missions have been conducted. A systematic review of the IAEA Safety Standards. Capacity building in Member States with nuclear power programmes and those

planning to embark on such a programme has been developed. 3 INIR missions have been conducted. A web-based platform to strengthen communication has been launched A review of INES has been initiated. A number of meetings have been held, including:

on the IAEA RANET on Nuclear Liability (INLEX) in building the necessary infrastructure for a nuclear power programme; and on the establishment of a Technical and Scientific Support Organizations Forum.

The Action Plan

21

There seems to be a disconnect between the

Action Plan and the necessary concentration

of efforts on the authoritative identification

and correction of the deficiencies that

caused Fukushima Daiichi

22

Why to divert attention to generic nuclear

safety issues rather than concentrate efforts

in the deficiencies of Fukushima Daiichi?

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Why the successful Chernobyl experience is not used?

First, authoritatively, identify what has happened:

A few months after Chernobyl, the IAEA had organized a high-level technical assessment of the accident causes, which was recorded by INSAG.

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Second, authoritatively, assess the consequences:

For the Chernobyl aftermath, the IAEA launched:

the “Chernobyl Project”

The “Chernobyl Conference” and

the “Chernobyl Forum”,

which produced a solidly based, authoritative account of the

consequences of the accident.

INTERNATIONAL

CHERNOBYL PROJECT

EC FAO IAEA ILO

UNSCEAR WHO WMO

27 <37 kBq m-2

555-1480 kBq m1480-3700 kBq m -2-2

-2 37-185 kBq m185-555 kBq m -2

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Sey m

Sos na

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Oka

Oka

ORSHA

Yelets

Baranovichi

SMOLENSK

BRYANSK

KALUGATULA

OREL

KURSK

POLTAVA

KHARKOV

CHERKASSY

ZHITOMIR

ROVNO

Ternopol

Khmelnitskiy VINNITSA

BerdichevBelaya Tserkov

Pinsk

Lida

MolodechnoBorisov

Mozyr

Novozybkov

KrichevCherikovBykhov

Gorki

Roslavl

Kirov

Lyudinovo

Dyatlovo

BolkhovMtsensk

Plavsk

Aleksin

Kimovsk

Novo-moskovsk

KhoynikiBragin

ChernobylPolesskoje

NarodichiKorosten

Novograd Volynskiy

SarnyOvruch Pripyat

Shostka

Slutsk

Soligorsk

Novogrudok

CHERNIGOV

GOMEL

SUMY

BELGOROD

VILNIUS

MOGILEV

KIEV

MINSK

B E L A R U S

U K R A I N E

R U S S I A

Efremov

Slavutich

Narovlya

Bobruysk

Chancellor Angela Merkel, who at the time was

Minister of Environment of Chancellor Helmut Kohl, was the President of the Chernobyl Conference

29 29 29 29

Recovery: Chernobyl Forum

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Parallel International Initiatives

UNSCEAR: Estimate of the global impact

WHO: Assessment of doses incurred

ICRP: Lessons learned

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3. Lesson being learned

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Radioactive discharges from Fukushima

?

Less than Chernobyl?

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1.2 1019 Bq

131 I 55% (50 000 000 Ci) 3,2 1018 Bq

134,137 Cs 33% 4,0 1017 Bq

Noble gases: 100% 7,0 1018 Bq

Discharges from Chernobyl

21 March, 2012 38

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Calculated air dose rate (shaded area) and measured (plot with values) air dose rate] The Universal Time Constant (UTC) is presented at the top (Japanese Standard Time: + 9 hours).

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Belorus

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Ukraine

Radiation Survey in Iitate Village (飯舘村 ) (conducted on March 28th and 29th) •On 22 April 2011, residents asked to leave within a month •In early June about 1,500 residents remained.

•By August only about 120 residents remained

Soil Contamination Levels in Iitate

Evacuees & Doses

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Evacuees

‘As many as more than 110,000 people have been evacuated’ [sic]

Chernobyl Ucrania 91,406 Belarus 24,725 Russian Federation 186

Total 116,317 (187 towns)

Contribution to doses

Te + I

134 Cs 137 Cs

50 50 50

Summary of radiation doses to the main population groups due to the Chernobyl accident

Population group Number (ths.) Mean thyroid dose (mGy)

Mean effective dose in 1986-2005 (mSv)

Workers (1986-1990)

530 N/A 117

Evacuees (1986) 115 490 31

‘Area of strict control’ (in B, R, U)

216 N/A 61

Belarus, Ukraine and 19 Russian regions

98 000 16 1.3

Distant European countries

500 000 1.3 0.3

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Fukushima dose bands

More affected locations of Fukushima prefecture (examples, committed dose from the first 4 months only) Namie, Iitate: 10-50 mSv; Katsurao, Minami-Soma, Naraha, Iwaki: 1-10 mSv

Rest of Fukushima prefecture: 1-10mSv Neighbouring prefectures: 0.1-10 mSv

Variation of Air Radiation Dose Rate in Iitate Village Office (7μGy/h after 3 months)

Cumulative Dose at Iitate Village Office and Magata

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annual dose mSv/year

~100 ~ 10 ~ 2.4 ~ 1

Natural Background

TYPICALLY HIGH

AVERAGE

MINIMUM

VERY HIGH Few people In few areas ⇒

Many people In many areas ⇒

Majority of people around the world ⇒

Nam

ie, Iitate

Katsurao,

Minam

i-Soma,

Naraha, Iw

aki

Iitate?

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Chernobyl drama: thyroid

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Chernobyl Thyroid doses

Average → 300 mSv? Higher → 10 000 mSv?,

Or more?

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Thyroid cancer in Chernobyl

Children received substantial thyroid doses due to the consumption of contaminated milk.

In total, about 7000 thyroid cancer cases were detected.

More than 99% of cases were successfully treated, but fifteen died.

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Thyroid dose bands (mSv) More affected locations of Fukushima prefecture

(examples, committed dose from the first 4 months only) Namie: 10-100 adults and 10y; 100-200 1y; Katsurao, Minami-Soma, Naraha: 10-100 all ages Iwaki: 1-10 adults; 10-100 for 10y and 1y

Rest of Fukushima prefecture (less affected): 1-10

adults; 10-100 for 10y and 1 y Neighbouring Japanese prefectures: 1-10

60 Calculated rain intensity (shaded area) and I-131 air concentration accumulated in vertical air column (red contours)]

The Universal Time Constant (UTC) is presented at the top (Japanese Standard Time: + 9 hours).

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Nuclear safety

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Prevention

Prevention of accidents cannot be solely based on

deterministic dogmas:

maximum credible accidents,

design basis accident, etc.

Rather, prevention should be supported by wide

quantitative criteria, within a probabilistic context,

a priori of design and operation.

Quantitative standards for siting and design

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The big lesson

The big lesson of Fukushima is to

confirm that mitigation may be even

more important than prevention.

Why?

….because Fukushima confirmed:

the dominance of

the implausible & unpredictable

over

the unlikely but foreseeable.

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Nuclear safety experts might be…

…ignoring a priori the possibility of

unpredictable causes of accidents,

concentrating on what they already know,

and then

struggling to intellectualize, a posteriori, the

factual occurrence of no-prevented causes.

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Mitigation!

It should be accepted that

- however robust the prevention is -

there is always the possibility of implausible

unpreventable events…and… in our view,

…mitigation should therefore became

paramount for nuclear safety

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What mitigation means

1. Containing radioactivity to reduce releases

2. Protecting people to reduce doses

Inadequate contention

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Protecting people: Shared Objetives

1. To regain control of the situation;

2. To render first aid and treatment of injuries;

3. To prevent deterministic effects;

4. To limit stochastic effects;

5. To resume normal social and economic activity.

72

Relevant lessons being learned

Misuse of

nominal risk coefficients

September 11-12, 2011

Discharges

Modeling

Collective doses

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Collective Dose x Nominal Risk Coefficient = Nominal Deaths

5%/Sv X =

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Chernobyl: Consequences of the Catastrophe for People and the Environment

Annals of the

New York Academy of Sciences

Alexey V. Yablokov (Editor), Vassily B. Nesterenko (Editor), Alexey V. Nesterenko (Editor),

Janette D. Sherman-Nevinger (Editor)

It concludes that based on records now available, some 985,000 people died of cancer caused by the Chernobyl accident!

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Will I be one of the 500,000?

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Misuse of the fundamental safety

principles

Justification of Actions

Optimization of Protection and Safety

Individual Dose Limitation

Justification

September 11-12, 2011

Justification

Good > bad

Is evacuation justified?

Ramsar, Iran If some of the evacuation in Fukushima is justified, why is not

justified to evacuate some of the inhabitants of this city?

Optimization

September 11-12, 2011

Optimization

• Best under the prevailing circumstances

88

Radiation harm Social harm

Radiation harm +

Social harm

→ safety Optimal

Harm

Individual Dose Limitation

What is the maximum tolerable level of individual risk regardless of justification and optimization?

September 11-12, 2011

90 21 March, 2012 90

Natural background

radiation

Expected additional

dose

Activity introduced

Dose limit (線量限度)

Planned exposure situation

91

mSv in a year 1 0.01

Restrictions on the additional

individual doses attributable to

regulated practices (additional annual dose)

↑ Dose constraint

↓

Dose Limit

Regulatory exemption

Extant Sources

September 11-12, 2011

93

21 March, 2012

93

Aver- table dose 回避線量

Resi- dual dose

残存線量

Extant

dose Refe- rence level

参考レベル

Extant radiation source in the aftermath (Emergency or existing exposure situation)

94

Simplified summary of

individual dose restrictions

(in mSv in a year)

NO INDIVIDUAL/SOCIETAL BENEFIT ABOVE THIS

DIRECT OR INDIRECT BENEFIT TO THE INDIVIDUAL

SOCIETAL, BUT NO INDIVIDUAL DIRECT BENEFIT

Exclusion, exemption, clearance

100

20

1

0.01

A typical question from the Japanese public is:

Why doses of 20 to 100 mSv per year are allowed now,

after the accident, when doses greater than 1 mSv per

year were unacceptable before the accident?

The Japanese expression for the 1mSv/y dose limit,

線量限度, [線= beam,量= amount,限=border,度=time]

is unequivocal: dose amount not to be exceeded in the time.

B A C K G R O U N D S P E E D

Protection of children

• Parents do not

believe that children

are adequately

protected by the

radiation protection

standards

98

The protection of children from the consequences of the accident has been of particular concern in Japan

99

Detriment-adjusted nominal risk coefficients for stochastic effects after exposure to radiation at low dose rate

[% Sv-1] Nominal

Population Cancer & leukæmia

Hereditable

Total

Whole

5.5 0.2 5.7

Adult

4.1 0.1 4.2

Rounded value used in RP standards⇒~5%Sv-1

30%

100

"Contamination"

Connotations that:

worsened the lives of residents,

generated anxiety, and

ruined the economy.

<37 kBq m-2

555-1480 kBq m1480-3700 kBq m -2-2

-2 37-185 kBq m185-555 kBq m -2

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Sto

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Be

rezi

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De s

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De s

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D n ep r

DneprRoska

Sey m

Sos na

Osk

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Vo

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la

Pse

l

S oz h

Oka

Oka

ORSHA

Yelets

Baranovichi

SMOLENSK

BRYANSK

KALUGATULA

OREL

KURSK

POLTAVA

KHARKOV

CHERKASSY

ZHITOMIR

ROVNO

Ternopol

Khmelnitskiy VINNITSA

BerdichevBelaya Tserkov

Pinsk

Lida

MolodechnoBorisov

Mozyr

Novozybkov

KrichevCherikovBykhov

Gorki

Roslavl

Kirov

Lyudinovo

Dyatlovo

BolkhovMtsensk

Plavsk

Aleksin

Kimovsk

Novo-moskovsk

KhoynikiBragin

ChernobylPolesskoje

NarodichiKorosten

Novograd Volynskiy

SarnyOvruch Pripyat

Shostka

Slutsk

Soligorsk

Novogrudok

CHERNIGOV

GOMEL

SUMY

BELGOROD

VILNIUS

MOGILEV

KIEV

MINSK

B E L A R U S

U K R A I N E

R U S S I A

Efremov

Slavutich

Narovlya

Bobruysk

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‘Contamination’ in consumer products

• The international intergovernmental agreements on acceptable levels of radioactivity in consumer products are incoherent and inconsistent.

• The situation created serious problems in Japan.

Foodstuff

Water

Non edible

106

Incoherence in drinking liquids

+

+

= 10 Bq/l for 137Cs

= 1000 Bq/l for 137Cs

107

Incoherence in non-edible vs. edible

+

+

= 100 Bq/kg for 137Cs

= 1000 Bq/kg for 137Cs

108

Guidance values in Japan

New radiation limits for food in Japan

• On 22 December 2011 the Japanese government

announced new limits for cesium in food.

(The new norms would be enforced in April 2012).

• Rice, meat, vegetables, fish: 100 Bq/Kg (500 Bq/Kg),

• Milk, milk-powder, infant-food: 50 Bq/Kg (200 Bq/Kg)

• Drinking water10 Bq/Kg (200 Bq/Kg)

?

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Stigma

• Those affected by the accident suffer from stigma

due to their association with radiation and

radioactivity.

• Consequently, they also suffer from psychological

effects harmful to health,

For many there is a social stigma associated with being an "exposed person"

Stigma is responsible for anxiety and

psychological trauma on people

115

115

Sterility (People sincerely believe that school girls in Fukushima will not be able to have a baby in future!)

Would we be able to

have a baby?

116

116

Stigma is responsible for great apprehension among pregnant women and probably for unnecessary terminations of pregnancies.

Pregnancy

Should I terminate my pregnancy?

117

4. The Argentine approach

Atucha I 357 MW(e)

Operates since 19th March 1974

Atucha II 745 MW(e)

Atucha NPP

119

Embalse NPP 648 MW(e)

operates since April 25th 1983

‘Stress tests’

http://www.foroiberam.org

Results: are being cross checked until May, and will be jointly reviewed in June 2012.

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Siting: common sense

Prevention Probabilistic criteria. Not academic, but regulatory!

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Some of Atucha’s prevention strengths

Diverse and independent shout down systems (control roads and injection of neutron poisons).

Unique on-line leak-before-break-system (tritium) Greater volume of coolant per unit power. Supplementary heat sink: Moderator at low T. Greater thermal inertia. Gentler plant response Longer time for recovery actions. (High pressure injection system to mitigate hypothetic piping breaks is not required: water

in the moderator expands and diverts to the core through the upper plenum. )

126

Containment

127

Natural uranium fuel: Impossibility of criticality accidents Less energy per unit mass (MW/ton)

PHWR PWR 14 70

12 60

10 50

8 40

6 30

4 20

1 10

0 0

(MW/ton)

128

Emergency response

• The American Nuclear Society concluded that the

severity of the Fukushima Daiichi accident was

exacerbated by an unclear chain of command.

129

Emergency response in Argentina

In Argentina, a centralized and unique conduction

is established by law → ARN

Submission to ARN: Licensee, Civil Protection &

Defence, Gendarmerie, Police, local governments.

Permanent coaching of the involved organizations

and verification of the response capacity: drills

with the participation of the population.

5. Epilogue

Many lessons can be extracted from the

Fukushima accident experience.

We have the ethical duty of learning from

these lessons and feeding-back the results

into the international system.

132

Fukushima is reassuring, because in spite of

the amazing scenario of deficiencies, as far

as we know, no one has so far received a

lethal dose of radiation!

But reassurance should not be

misunderstood as complacency

133

Reflections

The nuclear community, namely governmental agencies,

regulators and

industry,

should learn, understand and apply the concrete lessons on safety deficiencies derived from Fukushima.

134

Is the international nuclear community

prepared to identify the NPPs that do not

comply with elementary safety requirements

for

siting,

emergency energy supply,

and, fundamentally, containment?

135

Generic stress tests or action plans are not really needed to identify such NPPs.

E.g., NPPs that do not have efficient

containment, or even no containment at all,

are well known:

they shall shut down!

"Plus ça change, plus c’est pareil

The more it changes, the more it's the same thing”

J.B.A. Karr

137

www.arn.gob.ar

+541163231758

Av. del Libertador 8250 Buenos Aires

Argentina

Thank you!

Containment?

1250 MW(e) - Start up: 1988 – Closure date: 2023 (?)