how to improve safety in regulated industries - the nuclear accident in fukushima

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Eidgenössisches Nuklearsicherheitsinspektorat ENSI

How to improve safety in regulated industries

The nuclear accident in Fukushima

Presentation for October 16th 2012

2Presentation October 16th 2012F. Meynen, Section Head ENSI - MEOS

Content

1. The accident - General Overview2. ENSI – Reports3. Human and organisational factors

• Origin and development of the accident• Management of the accident• Consequences of the accident

4. Management of the accident• Lessons learned from a Technical perspective• Lessons learned from a Human Factors perspective

5. Conclusion6. Final words

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Earthquake on March 11th, 2011 Power Production

The earthquake on March 11th, 2011 at 14:46 caused the shutdown of several conventional and nuclear power stations.Nuclear sites:- Fukushima Daiichi (1 - 6)(unit 4 - 6 in outage)

- Fukushima Daini (1 - 4)- Onagawa (1 - 3)- Tokai 2 (unit 1 indecommissioning phase)


Earthquake on March 11th, 2011 Industrial sites

Refinery in Ichihara Oiltank in Minami Soma

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Earthquake on March 11th, 2011Infrastructure

Access difficulties – Heavily damaged roads


Earthquake on March 11th, 2011 Consequences for Nuclear Power Stations

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Tsunami on March 11th, 2011Transport infrastructure

Airport of Sendai

Port of Kamaishi


Tsunami on March 11th, 2011Flood wave at Fukushima site

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Tsunami on March 11th, 2011Hydrogen Explosions


ENSI reports about Fukushima accident

These reports are available on ENSI website: www.en si.ch – Dossiers

Event Sequences

Human andorganisational factors

Lessons learned and checkpoints

Radiology

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ENSI Action Plan Fukushima

Action Plan

1. Earthquake 2. Flooding 3. Extreme weather conditions 4. Long term station blackout (SBO)5. Lost of the ultimate heat sink6. Containment-pressure relief and hydrogen

management7. Emergency management in Switzerland8. Safety culture9. Experience feedback10. International oversight and cooperation 11. External storage facility (Reitnau, Switzerland)

ENSI – Focus in 2012


Human and organisational factorsENSI - Analysis

1. Origin and development of the accident

2. Management of the accident

3. Consequences of the accident

Why did a Station Blackout (SBO) occur on 11 March 2011 after the earthquake and the tsunami?

Why did damage occur to the fuel assemblies and why didall the safety barriers fail, with the subsequent r elease of massive amounts of radioactivity into the environme nt?

Why were the plant staff and the public exposed and whywas the environment contaminated?

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EU-Stresstest Medienkonferenz, 10. Januar 2012 – R. Sardella (ENSI) 13

Origin and development of the accident

Aspects related to safety culture

Aspects related to strategy and practice of government supervision

Why did a Station Blackout (SBO) occur on 11 March 2011 after t he earthquake and the tsunami?

Two kinds of explanations from a Human Factors perspectiv e within a whole set of hypotheses laid out in the E NSI - Analysis

Inappropriatemeasures to

protect the plant against a tsunami

Overall difficulty to consider possible an

event which has a lowprobability to occur

Oveerallunfavorable

corporate culture Complacency and

excessive trust

Conflict between safety and cost

efficiency

Deficiencies regarding the development of a culture of learning in the organisation

Insufficient independence of the regulatory body

Structural deficiencies in the overall supervision

system

Deficiencies in the supervision of

emergency measures andin the underlying

legislative and regulatory framework

Insufficient supervision



Nuclear supervision and energy policy in JapanOrigin and development of the accidentBackground information

The structure of the Japanese nuclear sector is (was) very complex - a large number of different players!

Risk of lack of independence and transparency in the supervision of nuclear safety!

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Management of the accident

Organisationalaspects

Human aspects

Documentation

Why did damage occur to the fuel assemblies and why did all the safety barriers fail, with thesubsequent release of massive amounts of radioactivity int o the environment?

Inappropriate measures to manage the plant during an

accident with a cumulative loss of safety functions

Three kinds of explanations from a Human Factors perspect ive within a whole set of hypotheses laid out in the ENSI - Analysis



Management of the accidentOrganisational aspects

• Delayed decisions• Deficiencies in information and • protective measures of the general public

Complex crisisOrganisation

Lack of clarity in the roles

Communications disrupted

Unsuitability of some crisis centers

Failures in communication between the two crisis centers in

the government building

Difficult to know or even to appreciate the situation on-site

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Management of the accidentHuman aspects

Difficult to have an exact appreciation of the plant state due to loss of most of the information

Difficulties to implement severe accident managemen t measures

• Environment conditions: aftershocks, plant damages, loss of electricity, radiological situation at the plant and in the MCR

• Number of people available at the site

• Difficult to implement actions

• Lack of protective measures for intervention teams

Difficulties to find how to restart safety functions wi th the tools and means available in a rapidly worsening stuation

• Operating crews are dependant on the tools and instruments available (or not available at the site)

• Lack of training

Difficulties to communicate during interventions (b etween local and MCR / Crisis Center)

Individual and collective stress


Management of the accidentDocumentation

Procedures and Emergency plan

insufficiently took intoaccount …

• …the risk of simultaneous destruction of all infrastructure.

• …the lack of accessibility to certain equipment / systems.

• …the inability to connect the installation with the mobile emergency power supply.

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Consequences of the accident

Why were the plant staff and the public exposed and why was the environment contaminated?

Delays in the management of the event

• Cooling by injecting seawater• Release of steam• Control hydrogen

Delays in the disclosure of information about radio activity levels on-site and off-site

Tendency to communicate information which did not s pecify the risks

Delays to protect the public

This demonstrates that it is still necessary to imp rove:

Proactive information and communication on accident s and incidents; natural or industrial

Communication in crisis situations must satisfy the need of the population for clear and understandable information


Earthquake informationJapan Meteorological Agency (JMA)

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Management of the accidentLessons learned from Fukushima from a Technical per spective

Need to strengthen the protection of facilities against natural hazards

• diverse water supply (wells, reservoirs, etc.)

Examples:

• diverse power sources (off-site supply, external emergency power system, etc.) ensured by different cable routes

• better flood protection of the emergency diesels and associated cooling systems

could have minimised the consequences of the tsunami


Comparison of building structuresLessons learned from Fukushima in a Technical persp ective Background information

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Safety featuresLessons learned from Fukushima in a Technical persp ective Background information

Common Mode Failure (CMF):Failure of two or more structures, systems and components in the same manner or mode due to a single event or cause.

Common Cause Failures (CCF): Failure of two or more structures, systems and components due to a single specific event or cause.

«Redundancy» «Diversity»

«Separation»

«Defense in Depth»

«Passive Safety Systems»

«Active Safety Systems»


Operational experience feedbackLessons learned from Fukushima in a Technical persp ective Background information

Blayais, 27.12.1999

Flood over the sea walls after combination of tide and high winds

Forsmark, 25.07.2007

Short circuit in the switchyard resulted in a severe disruption of the auxiliary and emergency power supply

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Management of the accidentLessons learned from Fukushima from a Human Factors perspective

People which operate a plant need a lot of information , tools, instrumentation, protective measures, management support, documents, organisational and training measures… to be able to perform their taskssuccessfully.

The human performance is a result of all these factorsduring normal and accidental situations. All thesefactors have to be considered as “Factors of success” or “Failure factors”.

During an accident, if these supports are not availa bleor not completely usable / adequate for the situation , then the workers (individually and collectively) are “deprived”, whatever their commitment and motivation.

From a human factors perspective, everything must b e done so that the teams are best supported in managi ng situations that require emergency actions to protec t the safety goals or to recover the safety functions.


Management of the accidentLessons learned from Fukushima from a Human Factors perspective

We do not mean here that the human factor is the “weakest link”. On the contrary, in many situations, operators and organisations are able to find “ultimate solutions”.

But…beyond these exploits… we have to ensure that teams "always“ have information resources, control means, procedur es, knowledge, ... to handle all possible events.

Otherwise, we need to give to the teams, the means which help them to ensure their role as “producers of reliability”.

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HF perspectiveLessons learned from Fukushima event

We need to continue:

To adopt appropriate measures to protect the nuclea r plants against the consequences of a severe acciden t exceeding standards taken into account during desig n (even if the probabilities of such events are very low )

To have on- site and at the crisis centers, organisa tionswith the knowledge to fully play their role efficie ntly

This also includes cultural, organisational and indi vidual capabilities to manage unexpected/unanticipated

situations!



HF perspectiveLessons learned from Fukushima event

We need to continue:

To take into account new knowledge & skills in regu latory requirements and safety guidelines

To have on-site and in each crisis center means ada pted to allow teams to assess efficiently the state of the plant and

to continuously update this assessment

To develop and continuously optimize the conditions in which the human actions are performed by personnel

during emergency situations

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Conclusion

• Independency• Protection of the population

and the environment• Communication• Preparation for the

management of crisis situations

• Taking into account extreme hazards• Appropriate technical and human

resources to cope with the event• Develop a good safety culture

• Preparing staff training• Appropriate materials and documents• Exemplarity, responsibility and proactivity

Exemplarity and Commitment of all actors involved in safety

Autoritiesmeasures

On site measures

Utilities measures


Final words

Safety is not a state –

Safety is a process

Authority

Environment

Unit

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Information Sources

• METI (Ministry of Economy, Trade & Industry) • NISA (Nuclear and Industrial Safety Agency)• TEPCO (Tokyo Electric Power Company)• JAIF (Japan Atomic Industrial Forum)• JMA (Japan Meteorological Agency) • IAEA (International Atomic Energy Agency)


Thank you

very much

for your attention!

how to improve safety in regulated industries - the nuclear accident in fukushima

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