Office for Nuclear Regulation

This website uses non-intrusive cookies to improve your user experience. You can visit our cookie privacy page for more information.

Lateral Restraint Tower Ventilation Plant Construction Crane Lifts Readiness Review on Sellafield Ltd's MSSS retrievals project at Sellafield

Executive summary

Purpose of Intervention

The purpose of the intervention was to inspect SL's implementation of its crane safety case and crane proposal triggered from its Licence Condition (LC) 22 arrangements, and to gain assurance that SL is in a state of readiness to safely commence project implementation for the proposed construction crane lifts. The findings of the intervention will be used to inform the regulatory decision on SL's request for ONR's agreement to commence the lifting operations.

MSSS is a legacy facility on the Sellafield site that was built in the 1960's for the underwater storage of fuel cladding arising from decanning of Magnox fuel elements. The MSSS facility is identified as a national decommissioning priority, as such, a programme of work is underway to retrieve the waste and export it to downstream facilities for storage in more modern/acceptable containment. One of the key enablers for the MSSS retrievals programme is to install a new ventilation system within MSSS facility. This will provide improved aerial abatement via a new HEPA filtration system which is required when all three Silo Emptying Plant (SEP) retrieval machines are operating. Details of each of the lifts to be carried out in MSSS are contained within a Composite Crane Safety Assessment (CCSA) that combines generic risk assessment elements across the 12 cranes. This has been assessed by ONR and judged to represent an adequate safety case methodology for use of mobile cranes at the MSSS site. Together with the CCSA, MSSS has produced a Crane Proposal and Crane Scheme that forms the safety case for of a construction crane to install the LRT ventilation plant. These lifts represent the fourth set of lifts ONR has assessed as part of the CCSA methodology.

Interventions Carried Out by ONR

Licence Condition 22 (LC 22) requires the licensee to make and implement arrangements to control any modification or experiment carried out on any part of existing plant or process which may affect safety. The scope of this intervention was to inspect MSSS facility from a plant, processes and people perspective and assess the licensee's readiness to safely commence the proposed construction lifts.

Given ONR's previous assessment of the CCSA and related agreement of the safety case methodology for the use of mobile cranes, I focussed the inspection on sampling key aspects of the crane scheme and supporting documentation. In particular, I examined consistency of the safety case with the CCSA, to ensure that SL's arrangements are appropriate to implement the crane scheme.

Prior to the inspection I obtained a copy of the crane scheme and used it to inform my preparation and define my sampling strategy. During the inspection I also sought assurance from SL's own governance process and that the licensee has followed this. The inspection comprised desktop-based discussions and evidence review. It was undertaken against LC 22 in accordance with ONR guidance Technical Inspection Guide (TIG) NS-INSP-GD-022, LC22: Modification or experiment on existing plant, Revision 3, December 2014. Additional consideration has taken account of the requirements of; the Management of Health and Safety at Work Regulations 1999 (MHSWR) and the Lifting Operations and Lifting Equipment Regulations 1998 (LOLER).

Explanation of Judgement if Safety System Not Judged to be Adequate

N/A - This was not a safety system inspection.

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

During the inspection I examined evidence of the licensee's compliance with its arrangements for the control of modifications to existing plant, correct implementation of the CCSA and lift planning in accordance with LOLER. On the basis of my sample, that the licensee is maintaining sufficient control.

With respect to ONR's TIG NS-INSP-GD-022, SL demonstrated:

In addition, during the inspection, the following observations were made:

Conclusion of Intervention

Based on our inspection findings, I judge that SL's implementation of the crane safety case triggered from its LC22 arrangements is adequate and therefore allocated an inspection rating of "Green" (no formal action) against LC22

SL has declared a 1 month slippage to the crane lift programme. Although I have identified a number of outstanding issues, I consider they are a product of the programme slippage rather than the licensee's compliance to their arrangements. The issues raised have no safety significance at this stage but will require addressing prior to ONR permissioning of the lifts. I have raised one regulatory issue to capture and monitor the readiness evidence I consider outstanding. Additionally, I have raised a second regulatory issue for SL to consider improvements and simplification of terminology within the command and control arrangements. No significant shortfalls were identified in the delivery of the safety function.