The 1st International Forum on the Decommissioningof the Fukushima Daiichi NPSApril 11, 2016

Session III – Risk Assessment

Iwaki-shi, Fukushima, JapanRisk Assessments for the Decommissioningof Nuclear Facilities
Andrew Orrell
Division of Radiation, Transport and Waste Safety
Waste and Environmental Safety Section

IAEA
International Atomic Energy Agency

IAEA Statute• The IAEA Safety Standards have a statusderived from the IAEA’s Statute, whichauthorizes the IAEA “To establish or adopt, inconsultation and, where appropriate, incollaboration with the competent organs of theUnited Nations and with the specialized
agencies concerned, standards of safety forprotection of health and minimization of danger
to life and property ... and to provide for theapplication of these standards”.
In 1958, the IAEA published its first Safety
Standard, Safety Series No. 1, Safe Handling ofRadioisotopes. Over the years, more than 200
publications were issued in the Safety Series.

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Promoting International Safety
Standards Since 1958

https://www-ns.iaea.org/standards/documents/general.asp

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> 200 Safety Standards published which reflect an international
consensus on what constitutes a high level of safety for protecting
people and the environment, and are a cornerstone of the global nuclear
safety regime.

•Regulating safety is a national responsibility, but international standards
provide a common basis.

•The Safety Standards support Member States to meet their international
obligations (treaties, conventions, agreements).

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Safety Fundamentals• A single top level (fundamentals••••level) standard
Policy document of the IAEA
Safety Standards Series
Present the fundamental safety
objective and 10 principles ofprotection and safety
Provide the basis for the safetyrequirements
Use “MUST” statements

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Safety Requirements
•••

•
•

General and specific SR
Elaborate on the basic objective
and the principles of SF-1, as they
apply to a specific activity or facility
Concise, reflect “WHAT”, ”WHO”
and “WHEN”; associatedexplanatory text describes “WHY”
the requirements exist
Use “SHALL” statements
The format and style facilitate theiruse for establishment of national
regulatory frameworks
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5Safety Guides
••

•

•

General and specific safetyguides
Provide recommendations andguidance on HOW to comply withthe safety requirements
Present international goodpractices, and increasingly reflect
best practices, to help users inachieving high levels of safety
Use “SHOULD” statements

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Supporting Publications

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http://www-pub.iaea.org/books/IAEABooks/Serial_Publications

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Decommissioning Objective
Removal of the radiological and nonradiological hazards associated withthe operation of a nuclear facility orsystem that will allow the facility to bereleased from regulatory control; andprotect the worker, general public andthe environment during the process.
Hazards analysis and risk (safety)
assessment is a central element ofdecommissioning projects...
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Risk assessment• The term "risk" includes all the relevant types of project-related risks,e.g. strategic, political, organizational, regulatory, technical, safety,commercial/financial, stakeholder related, etc., that may affect theprogress of a decommissioning project and/or jeopardize theachievement of the project objectives (removing the hazards while
protecting the public, worker and environment).
• Identification• What are the hazards and associated uncertainties?
• Evaluate• What are the probabilities and consequences?
• Mitigation• Prioritization and Decision-Making

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Decommissioning and Safety Assessment

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Quantitative Risk Assessment
Qualitative Risk Evaluation• Risk assessment and evaluation• Risk assessment and evaluation

are used to help prioritizationand decision-making in multifaceted and complex situations.

are used to help prioritizationand decision-making in multifaceted and complex situations.

• Complex risk management
situations have both threat andopportunity impacts.

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DRiMa: International Project on Decommissioning Risk
Management
http://www-ns.iaea.org/projects/drima/
The DRiMa project commenced in 2012 and completed in 2015, with over 40
representatives from 28 Member States. Final report pending.
••

There are well-established risk management
methodologies used in many industries andapplicable to decommissioning
Decommissioning projects generally recognize
project risks at two levels:• Strategic: Risk management at the strategic level••focuses on the management of assumptions(uncertainties) and strategic decisions during planning fordecommissioning (Initial to Final Decommissioning Plan);
key assumptions have a fundamental impact on thedecommissioning plan, and thus the uncertainties need to beanalysed as development of the plan progresses.
Operational: Risk management at the operational levelfocuses on risks to the decommissioning project associatedwith the project conduct (implementation of the Final
Decommissioning Plan)

During implementation of the decommissioning project all risks have to be continuously
managed to increase the probability of success in achieving the decommissioning objectives.

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Managing the Decommissioning and Remediation ofDamaged Nuclear Facilities (DAROD Project).
Project launched in January 2015, 23 countries participating.
Objective is to distil and disseminate practical knowledge forthe decommissioning and remediation of damaged nuclear
facilities from multiple perspectives.

Has three working groups to address perspectives related
to:• Regulatory oversight• Policy, strategy and planning• Technology issues

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Conclusions• The IAEA’s Safety Standards represent 5 decades of experience••••and expertise, and provide international consensus on what isneeded to achieve a high level of safety
Decommissioning standards take into account practices fromMember States with advanced programmes
Application of the Safety Standards to support safe and costeffective decommissioning
Input to the Safety Standards from the Member States andfeedback from their application essential for the IAEA work
The present efforts at the Fukushima Daiichi NPP both draw
from and contribute to the global expertise in safely addressing
the challenges of decommissioning, and a strengthened global
nuclear safety framework.

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Thank you for your attention !
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