Office for Nuclear Regulation

Corrosion and concealed and buried systems & Management of Non-active and Active storage Tanks and Vessels

Executive summary

Purpose of Intervention

The purpose of this intervention was to conduct an inspection to establish the adequacy of arrangements implemented under the site corrosion management programme. The work was carried out as part of the Office for Nuclear Regulation (ONR) planned intervention task sheet TS027 – “Management of Corrosion - Concealed and Buried Systems” and task sheet TS023 – “Management of Storage Tanks and Vessels”.

I carried out this inspection accompanied by the ONR Heysham B site inspector. The inspection took place from the 15th to 17th of January 2020, and involved discussions with a number of EDF Energy Nuclear Generation Limited’s (NGL) employees responsible for the operation and safety of the plant. A targeted plant walk down of the systems selected for sampling was also undertaken.

Interventions Carried Out by ONR

The primary aim of the inspection was to perform a review of the adequacy of the licensee’s arrangements for managing plant material condition of lagged pipework, storage tanks and buried pipework that are important for safety, against the requirements of licence condition (LC) 28 – Examination, Inspection, Maintenance and Testing (EIMT).

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

From the information that I have sampled I judge that the corrosion management programme at Heysham B is generally adequate.  However, I recommended a systematic review of staffing and how leadership and guidance in all aspects of the corrosion management issues on site are managed.  During a post visit discussion, the corrosion lead stated that SQEP resource has been identified and brought into the corrosion programme.  Furthermore, the programme for ranking of corrosion defects has also commenced following ONR’s intervention.   ONR will sample the adequacy of these improvements in a follow up intervention planned for Q2 2020.

The corrosion co-ordinator had a good understanding of corrosion degradation and could demonstrate his knowledge of the plant well.  Some good progress has been made at Station in addressing the corrosion issues; however, a comprehensive system of managing all corrosion defects was in progress and required attention from the corrosion team.  Following my post-visit discussions, Heysham B confirmed that they have increased the corrosion team’s resource, and are developing their corrosion ranking table to aid centralised management of corrosion issues.

ONR’s sampling of the maintenance schedule related to the CO2 system appeared to show Pressure System Safety Regulation (PSSR) driven inspection requirements.  This has been identified by the station’s self-evaluation and is being addressed the system engineer.  This has included a review of all inspection routines on the plant, identifying gaps and generating Maintenance Schedule routines for all vessels on the CO2 plant. ONR will sample the adequacy of these improvements in a PSSR vs LC28 MEVL follow up intervention planned for Q2 2020.

Conclusion of Intervention

I judge that, against the requirements of LC28, a rating of GREEN in accordance with ONR inspection rating guidance (CM9 2016/118606) is appropriate. This is based on the overall management of the corrosion issues at site and the site’s swift response to issues regarding a lack of SQEP resource in the corrosion management programme.  I have raised one Level 4 Regulatory Issue for the licensee to demonstrate the adequacy of the corrosion management SQEP resourcing and developing systems and processes to ensure all aspects of the corrosion management programme are adequately addressed.