Office for Nuclear Regulation

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Sellafield Ltd.'s nuclear licensed sites at Sellafield, Cumbria: Annual assessment of emergency management capability (Exercise AVATAR)

Executive summary

Purpose of intervention

The Office for Nuclear Regulation (ONR) undertakes all regulatory interaction with Sellafield Limited (SL, the site licensee) against a strategy defined by ONR's Sellafield, Decommissioning, Fuel and Waste Programme. The planned inspection schedule for the current regulatory year (covering April 2016 - March 2017), the content of which is guided by that strategy, defines those aspects of the site's operations that will be inspected over this period within SL's Emergency Preparedness organisation.

This intervention was undertaken to determine, through an emergency demonstration exercise, if the site is implementing adequately its site-wide arrangements for compliance with Licence Condition 11 (Emergency Arrangements). This intervention fulfils the requirement set by ONR for SL to demonstrate the site's emergency management performance on an annual basis, based on a safety-driven scenario.

Interventions Carried Out by ONR

Licence Condition 11 (LC11) requires the licensee to make and implement adequate arrangements to deal with any accident or emergency arising on the site and to ensure that such arrangements are rehearsed periodically.

Our inspection, which comprised an assessment of a site-wide emergency demonstration exercise (Exercise AVATAR) that was planned and managed by the licensee, was completed in accordance with the following ONR guidance:

Through discussion with ONR, SL developed a challenging scenario for this exercise focussed around a significant flooding event on the site caused by extreme weather conditions (very heavy rainfall). This scenario was designed to test SL's emergency capability and response across the whole of site, with a focus on certain facilities which experienced simulated flooding due to the topography of the site. The scenario also simulated disruption to the site's electrical supplies due to the flooding, and casualties associated with the unfolding events. The scenario also required specific nuclear and radiological challenges to be assessed and resolved / mitigated by SL during the course of the exercise. It also rehearsed a number of challenging aspects such as dealing with out-of-hours emergencies, and the deployment of recently-procured resilience equipment (in place to mitigate the simulated floodwater on site and so protect specified facilities).

The exercise was assessed by a multi-discipline team of eleven ONR inspectors located at key positions around the site. This team included three ONR security inspectors who assessed security-related aspects of the scenario.

Explanation of Judgement if Safety System Not Judged to be Adequate

Not applicable; this was not a Safety System inspection.

Key Findings, Inspector's Opinions and Reasons for Judgements Made

This was a challenging exercise scenario, placing demands on many facilities across site, as well as significantly challenging SL's command and control infrastructure and abilities due to the site-wide nature of the simulated events.

I consider that SL demonstrated an adequate emergency response performance in this exercise. My assessment team and I consider that SL would have coped adequately had this been a real event, and as such, I awarded a Pass rating.

However, I also noted a number of minor areas for improvement. For example SL experienced difficulties with the timely completion of its roll call and muster for one facility, and an action tracking Regulatory Issue has been raised to follow this up. ONR will also liaise with SL regarding other minor exercise observations as part of a planned exercise feedback meeting. Both these matters will be progressed as normal regulatory business.

Overall though, based on this demonstration, I consider SL has implemented effectively its arrangements for compliance with LC11 and I thus awarded an inspection rating of Green (no formal action).

Conclusion of Intervention

ONR shared our observations with SL at a Hot Debrief session held the day following the exercise. I welcomed the strong degree of alignment between our observations and those of SL's own internal regulator, who performed a parallel assessment of the emergency exercise.

Importantly, SL had also identified the difficulty with the roll call and muster performance, and stated it would be proactively seeking to address this matter.