Date(s) of inspection:
- August 2023
Aim of inspection
To gain regulatory confidence in RRSL’s readiness to commence active commissioning (AC) under LC21 arrangements following a modification proposal under LC22 arrangements to commence AC prior to completion of all inactive commissioning activities.
Intervention conducted on-site by the ONR project inspector and human factors specialist inspector, utilising relevant good practice from.
Subject(s) of inspection
- LC21 – Commissioning – Rating: Not rated
- LC22 – Modification or experiment on existing plant – Rating: Green
Key findings, inspector’s opinions and reasons for judgement made
RRSL is currently undertaking Inactive Commissioning of DPF Wetside and has proposed a modification to enter active commissioning using a phased approach. The modification outlines an initial phase where the type of items to be processed will be restricted, prior to the commissioning of a nuclear protection safety system. The introduction and processing of item types containing larger quantities of fissile material has the potential to result in an inadvertent criticality under certain fault conditions without the nuclear protection system to prevent the event. RRSL has proposed several human Safety Actions within its modification, associated with preventing the introduction and processing of item types with quantities of fissile materials that have the potential to present a hazard during the initial active commissioning phase.
We undertook an inspection to consider whether the safety measures claimed by RRSL were adequate and whether RRSL had adequate plans for their implementation prior to active commissioning.
We provided some advice and guidance to RRSL in improving the clarity, detail and completeness of the overarching strategy for commissioning however, we judged that these did not represent a risk gap and that no formal action was required.
We judged that RRSL had provided an adequate justification for the proposed active commissioning operations and were adequately progressing the implementation activities in preparation. There is no permissioning hold point associated with commencing active commissioning in line with RRSL’s proposal. We did not rate the inspection against LC21 as the focus was on the proposed changes to commissioning activities. The inspection was rated as Green (no formal action) against LC22.
We judged that RRSL had provided and adequate justification for the proposed active commissioning operations and were adequately progressing the implementation activities in preparation. The inspection was rated as Green (no formal action).