Office for Nuclear Regulation

Annual demonstration of emergency management capability (Exercise CITADEL) at Sellafield

Executive summary

Purpose of Intervention

The Office for Nuclear Regulation (ONR) undertakes all regulatory interactions with Sellafield Limited (SL), the site licensee, against a strategy defined by the ONR Sellafield, Decommissioning, Fuel and Waste (SDFW) Division.  The planned inspection schedule for the current regulatory year (covering April 2018 – March 2019), the content of which is guided by that strategy, identifies the Licence Conditions (LCs) that will be inspected over this period.

This intervention was conducted 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 capability 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.

ONR’s inspection, which comprised an assessment of a site-wide emergency demonstration exercise (Exercise CITADEL) 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 which focussed around a significant loss of containment event caused by seismic tremors and associated aftershocks. This scenario was designed to test SL’s emergency capability and response across the whole of site, with a focus on certain facilities which either experienced simulated loss of containment or were affected by the primary event. The scenario also simulated a coincident, conventional health and safety event within an office building which involved significant command and control challenges in terms of building evacuation, casualty recovery, overall emergency response and associated muster / roll call activities. 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 as the main event had the potential to escalate to a Severe Accident Management Strategy (SAMS) event.

The exercise was assessed by a multi-discipline team of ten ONR inspectors located at strategic 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 facilities across the site, as well as significantly challenging SL’s command and control infrastructure and abilities due to the site-wide nature of the simulated events.

Overall, 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 an actual event, and as such, I awarded a Green rating.

I noted some areas of good practice e.g. all casualties were rescued in a timely manner and roll-calls in the affected facilities were conducted efficiently and effectively. In addition, the command and control performance was judged to be good within the Sellafield Emergency Control Centre (SECC). 

However, a number of shortfalls were also identified. Specifically, with regard to operations at the Access Control Point (ACP) within Separation Area; significant  shortfalls were identified in the following areas:

In this regard, ONR welcomed the licensee’s alignment of its self-assessment findings to ONR’s findings, through the licensee being open, and self-critical.  

Accordingly, in response to the identified shortfalls; SL offered a partial re-demonstration covering elements of the exercise, targeting the areas listed above, which ONR has accepted. 

An action tracking Regulatory Issue has been raised to follow up on this partial re-demonstration together with other areas for improvement that were identified during the exercise. In the case of the latter, ONR requires Sellafield Ltd. to conduct a review of the adequacy of its LC 11 Emergency arrangements in relation to the findings identified and to respond to ONR detailing the outcome and any proposed action.

ONR will also liaise with SL regarding other minor exercise observations as part of a planned exercise feedback meeting. 

However, based on SL’s overall performance throughout this exercise, I consider that SL has implemented effectively its arrangements for compliance with LC11 and I thus awarded an inspection rating of Green (no formal action) here.

Conclusion of Intervention

ONR shared its 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 concurrent evaluation of the emergency exercise.

I plan to issue a letter agreeing to a partial re-demonstration of the exercise in the areas as detailed above and requesting that the licensee conducts a review of the adequacy of its LC 11 Emergency arrangements in relation to the findings identified as part of conducting this inspection and to respond detailing its findings and proposed action.

Overall, based on SL’s demonstration, I consider that the licensee has implemented effectively its arrangements for compliance with LC11 and I therefore awarded a rating of Green (No formal action) to this inspection.