Office for Nuclear Regulation

Sellafield, THORP, LC15 Compliance Inspection

Executive summary

Purpose of intervention

The Office for Nuclear Regulation (ONR) undertakes all regulatory interactions with Sellafield Limited (SL, the site licensee) in line with a strategy defined by the ONR Sellafield Programme. As part of this Strategy, ONR carries out Licence Compliance Arrangements Inspections. These examine whether SL’s site-wide arrangements to comply with the conditions of its nuclear site licence have been implemented adequately.

This intervention was undertaken to determine if the Thermal Oxide Reprocessing Plant (THORP) area is adequately implementing SL’s site-wide arrangements for compliance with Licence Condition 15 (Periodic Review), and in particular the arrangements for Short Term Periodic Reviews (STPRs).

Interventions Carried Out by ONR

Licence Condition 15 (Periodic Review) requires SL to make and implement adequate arrangements for the periodic and systematic review and reassessment of safety cases.

My inspection, which comprised discussions with SL staff and examination of plant documentation, focussed on the following aspects of STPRs at THORP:

I based my inspection on the questions provided in ONR’s Technical Inspection Guide for LC15.

Explanation of Judgement if Safety System Not Judged to be Adequate

Not applicable as this was not a Safety System inspection.

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

I judged, from the evidence presented, that SL’s site-wide arrangements for compliance with LC15 have been implemented appropriately at the THORP facility. In particular, I was satisfied that THORP had produced all its STPR reports in a timely fashion and is using appropriate inputs.

I nevertheless identified a few minor areas where THORP did not appear to be fully aligned with the site processes.  Firstly, STPRs at THORP focus on only the most significant areas of safety, whereas the site’s arrangements seek reviews considering safety more generally.  Secondly, where the reviews identify improvements, only those considered to be of the highest safety significance are taken forward in an auditable fashion (i.e. the process at THORP permits findings to be communicated to those responsible for their rectification but without any subsequent action-tracking to confirm their resolution). It is my opinion that these aspects are a restrictive interpretation of the site’s LC15 arrangements.

I also noted the significant workload expected for the next periodic reviews when fuel reprocessing at THORP ceases and the plant’s mode of operation changes.  I suggested that SL should develop better succession plans to cater for this workload so that an adequate cadre of suitably qualified and experienced safety case managers continues to be in post.

Conclusion of Intervention

These observations notwithstanding, I consider that the LC15 arrangements I witnessed at THORP meet ONR guidance requirements. I therefore awarded an IIS rating of 3 (adequate) against this Licence Condition.

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