Office for Nuclear Regulation

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Sellafield Inspection RST and EDT Settling Tanks

Executive summary

Purpose of intervention

The Office for Nuclear Regulation (ONR) undertakes all regulatory interaction with Sellafield Limited (SL, the licensee) against a strategy defined by the ONR Sellafield Programme.  My planned inspection schedule for the current regulatory year (covering April 2014 – March 2015), the content of which is guided by that strategy, defines the Licence Conditions (LC) that will be inspected over this period. 

This intervention was undertaken to determine if the Redundant Settling Tank (RST) and Effluent Distribution Tank (EDT) plants are adequately implementing the licensee’s site-wide arrangements for compliance with Licence Conditions 23, 28 and 34.  It follows an inspection of the First Generation Magnox Storage Pond (FGMSP) pond liquor control in September 2014 at which SL was rated as Below Standard for LC28.

The RST and EDT facilities were selected for inspection in view of their importance to the Sellafield site’s high hazard and risk reduction programmes.

Interventions Carried Out by ONR

I carried out a compliance inspection of the RST and EDT against Licence Condition 34 (LC34) (Leakage and escape of radioactive material and radioactive waste).  LC34 requires the licensee to ensure, so as is reasonably practicable, that radioactive material and radioactive waste on the site is at all times adequately controlled or contained so that it cannot leak or otherwise escape from such control or containment.

I also carried out a compliance inspection against Licence Condition 23 (LC23) (Operating Rules).  LC23 requires the Licensee to identify and comply with the conditions and limits necessary in the interests of the safety of its operations.

I also carried out a compliance inspection against Licence Condition 28 (LC28) (Examination, Inspection, Maintenance and Testing).  LC28 requires the licensee to make and implement adequate arrangements for the regular and systematic examination, inspection, maintenance and testing of all plant which may affect safety.

My inspection, which comprised discussions with SL staff, plant walk downs and examination of a suitable sample of plant documentation, was carried out jointly with an ONR process chemistry specialist inspector and an inspector from the Environment Agency.  The inspection focussed on the following areas:

The scope of LC arrangements implemented.

Evidence that LC34 control and containment duties are being met in the RST and EDT facilities.

Evidence that appropriate conditions and limits necessary in the interests of safety have been derived from the safety case and implemented effectively at RST and EDT to support safe operation.

Evidence that the licensee’s arrangements for the examination, inspection, maintenance and testing of plant that may affect safety are in place and implemented to support the safe operation of RST and EDT.

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

I judge, from the evidence presented, that the licensee’s arrangements for compliance with LC23, 28 and 34 have been implemented appropriately within the RST and EDT facilities.  The licensee has undertaken coordinated work over several facilities to reduce the potential risks from RST and to implement an asset improvement programme to improve the availability of EDT, a key facility for high hazard and risk reduction programme.   I consider that this represents good practice and encouraged the licensee to continue to seek opportunities to further reduce risks from RST.

In regard to LC28, I was pleased to find that the Plant Maintenance Schedules (PMS) contain both the maintenance required as well as proof tests.  This is an improvement from the September inspection of FGMSP where the exclusion of normal maintenance activities from the PMS led to a Below Standard (IIS=4) rating being awarded.

I identified a small number of minor shortfalls in the licensee’s documentation control, record keeping and sampling periodicity. Having reviewed those shortfalls, I am content that none present more than a minor safety concern. 

Conclusion of Intervention

The licensee has adequately implemented its arrangements for compliance with these LCs.  Given that the shortfalls I observed were all minor, I have recorded an IIS rating of 3 (Adequate) against Licence Condition 23 (Operating Rules), Licence Condition 28 (Examination, Inspection, Maintenance and Testing) and Licence Condition 34 (Leakage and escape of radioactive material and radioactive waste).

My observations were shared with, and accepted by, the licensee as part of normal inspection feedback. A number of minor actions were identified during the inspection which will be tracked through ONR’s Regulatory Issues database and followed up by the ONR Site Inspector as part of normal regulatory interactions.