Focusing on Fukushima Daiichi Deficiencies - A.J. Gonzales, Argentina
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Transcript of Focusing on Fukushima Daiichi Deficiencies - A.J. Gonzales, Argentina
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
8
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.
10
Deficiency 3
Inadequate containment and mitigation
devices to prevent the release of
substantial amounts of radioactive
material to the environment.
11
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.
15
16
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?
23
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.
24
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
Pr i py a t
Dr
nep -Bugski CanalPr i py a t
Sto
kho d
Go
ryn
’
Be
rezi
na
De s
na
Tete
rev
De s
na
D n ep r
DneprRoska
Sey m
Sos na
Osk
ol
Vo
r sk
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
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
30
Parallel International Initiatives
UNSCEAR: Estimate of the global impact
WHO: Assessment of doses incurred
ICRP: Lessons learned
31
33
35
3. Lesson being learned
36
Radioactive discharges from Fukushima
?
Less than Chernobyl?
37
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
39
40
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).
42
Belorus
43
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
48
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
51
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
54
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?
55
Chernobyl drama: thyroid
56
57
Chernobyl Thyroid doses
Average → 300 mSv? Higher → 10 000 mSv?,
Or more?
58 58 58
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.
59
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).
61
Nuclear safety
62
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
64
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.
66
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.
67
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
68
What mitigation means
1. Containing radioactivity to reduce releases
2. Protecting people to reduce doses
Inadequate contention
70
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
75
Collective Dose x Nominal Risk Coefficient = Nominal Deaths
5%/Sv X =
76
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!
77
78
Will I be one of the 500,000?
79
80
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
Pr i py a t
Dr
nep -Bugski CanalPr i py a t
Sto
kho d
Go
ryn
’
Be
rezi
na
De s
na
Tete
rev
De s
na
D n ep r
DneprRoska
Sey m
Sos na
Osk
ol
Vo
r sk
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
102
‘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)
?
111
112
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.
123
Siting: common sense
Prevention Probabilistic criteria. Not academic, but regulatory!
125
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 (?)