Office for Nuclear Regulation

LC23 compliance inspection of the Highly Active Liquor Evaporation and Storage (HALES) Operating Unit, on Sellafield Ltd.’s nuclear licensed site at Sellafield, Cumbria

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 Programme.  My planned inspection schedule PP5 for the current regulatory year (covering April 2015 – March 2016), the content of which is guided by that strategy, identifies the Licence Conditions (LCs) that will be inspected over this period.

I undertook this planned LC 23 inspection by meeting with facility representatives from the Highly Active Liquor Evaporation and Storage (HALES) Operating Unit (OU). This OU was selected for inspection since it controls the safe evaporation of Highly Active Aqueous Raffinate (HAAR), a product of fuel reprocessing at the site, and the interim storage of the evaporative product; Highly Active Liquor (HAL), prior to vitrification.  The safe operation of this facility is central to the control of one of the most significant hazards on the Sellafield nuclear licensed site.

Interventions Carried Out by ONR

The purpose of Licence Condition 23 (LC23) is to ensure that all operations that may affect safety are supported by an adequate safety case and that this safety case identifies the conditions and limits (Operating Rules) necessary in the interests of safety.

In light of the recent Operating Rule review which had been carried out by the Licencee, I chose to inspect the process that had been followed, the subsequent Operating Rules which had been generated and the implementation of a sample of Operating Rules which had been subject to the Operating Rule review but were not being changed.

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 consider that SL’s arrangements for compliance with LC 23 have been effectively implemented within the HALES OU. Furthermore, locally, the Licensee has developed a tiered approach to some of its Operating Rules and defined significant limits and conditions during the fault progression which require and define specific actions to terminate the fault.

The Licencee has provided guidance to the Evaporator D project to ensure that a similar, consistent approach is followed for this project that is currently in commissioning phase. A review had subsequently been carried out to ensure consistency across the two areas had been delivered.

I sampled the implementation of some of the extant HALES Operating rules and found them to be clear, well managed and provide a clear means of demonstrating compliance.

I consider the facility’s implementation of the site’s arrangements for LC23 is of a good standard. The licensee has exceeded the limits of extant site guidance and has provided evidence of being proactive and positive.  For these reasons, on balance, I consider the inspection findings merit an IIS rating of 2 (Good Standard) against LC23. This is consistent with the IIS ratings guidance, for which the relevant extract is:

“…Generally exceeds, guidance requirements. Site alert to and actively pursuing, potential improvements. Any suggestions from site inspector considered on merits..”

Conclusion of Intervention

My findings were shared with, and accepted by, the dutyholders as part of normal inspection feedback.  No ONR Regulatory Issues were raised as a result of this inspection.