WENRA Conclusions arising from the Consideration of the Lessons from the TEPCO Fukushima Dai-ichi Nuclear Accident

Posted May 24, 2012, 9:53 a.m.

On 21 March 2012, WENRA has discussed the work that members have been undertaking to learn lessons from the TEPCO Fukushima Dai-ichi nuclear accident (European Stress Tests process, national reports and timeframe).

WENRA emphasizes institutional (roles and responsibilities of governments, regulators and utilities) and cultural (continuous improvement) aspects of nuclear safety in addition to technical issues.

WENRA is ready to tackle further issues as necessary on the basis of the lessons learned from the Fukushima accident. WENRA’s commitment is to proceed along the path of defining or revising existing Reference Levels as well as developing guidance documents for practical use by regulators. WENRA has concluded that the following matters should be addressed or noted.

1 Institutional

I.1 Independence
Nuclear regulatory bodies should be independent de-facto as well as de-jure including being adequately resourced.

I.2 Roles and responsibilities
The roles and responsibilities of Government, nuclear regulator and utilities in responding to nuclear accidents should be clear taking account of national and organisational constitutions, capabilities and legal systems.

I.3 Periodic Safety Reviews
The need for adequate periodic safety reviews and the timely implementation of reasonably practicable improvements should be an established requirement.

I.4 Mutual assistance
WENRA will put in place arrangements for mutual assistance amongst regulatory bodies in responding to nuclear accidents in one of its members’ states.

2 Cultural

C.1 The underlying philosophy for sustained high standards of nuclear safety of continuous improvement is reinforced. No matter how high the standards the quest for reasonable practicable improvement must never stop. The identification of such improvements does not invalidate the existing basis for safe operation.

3 Technical

T.1 Natural hazards
WENRA will produce updated harmonised guidance for the identification of natural hazards, their assessment and the corresponding assessment for “cliff-edge” (margins) effects. Safety Reference Levels will be updated accordingly.

T.2 Containment in Severe Accident
WENRA will review Safety Reference Levels in light of the various measures identified to prevent containment overpressurisation, including those relevant for hydrogen mitigation and containment venting, and modify them if necessary.

T.3 Accident Management
WENRA will review Safety Reference Levels in light of the various measures identified in relation to organisational and material arrangements for preventing or mitigating a significant radiological release, and modify them if necessary.

4 Way Forward

WENRA has put in place specific working groups to address items I.4, T.1, T.2, and T.3 to work under the Reactor Harmonisation Working Group (RHWG). WENRA has determined that these work streams are priority work for the RHWG.

Details concerning the working groups, their tasks and timescales can be found in annex 1 to the present document.

The results from the stress tests and conclusions from the CNS 2012 will be incorporated as soon as they become available.

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