Lateral Restraint Tower Ventilation Plant Construction Crane Lifts Readiness Review on Sellafield Ltd's MSSS retrievals project at Sellafield
- Site: Sellafield
- IR number: 17-148
- Date: October 2017
- LC numbers: 22
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:
- The modification is under the control of plant management and being managed in accordance with the established arrangements. This was evidenced by close out of INSA recommendations and evidence of submission to the construction crane safety committee, Management Safety and Site Nuclear Safety Committee. In addition I noted that representatives of the different teams of the project had a good understanding of the safety case and the method statement.
- An adequate consideration of the operating limits and conditions, identification of safety mechanisms and safety related equipment including wind speed requirements and their incorporation into operating instructions. This was evidenced by review of the CCSA and confirming that the limits and conditions in the interest of safety have been adequately captured by the crane scheme. Where there were differences SL was able to demonstrate that their safety assessment justifies the changes thereby ensuring lifting risks are adequately controlled.
- An adequate understanding of the command and control arrangements. This was evidenced by interviewing the SL Construction Manager, SL Construction Coordinator, lift contractor Appointed Person and the i3 Lifting Engineer. Each was able to articulate their roles and responsibilities, safety case requirements and supervisiory and control arrangements necessary for safe execution of the proposed lifts.
- An adequate knowledge from the lifting personnel present, on technical aspects, internal arrangements and governance, safety aspects and emergency arrangements.
- Clear processes for the initial actions in the event of a crane incident as evidenced from the lift contractor Command and Control document.
- Evidence of adequate consideration of equipment condition before commencement of lifting. This was evidenced through discussion with the SL Construction Coordinator and contractors Appointed Person, a sample of SL's Method Statement and the SL S145 form. We were satisfied through this sampling that SL's arrangements provide for adequate examination and testing of lifting equipment before installation and use.
- Evidence of adequate consideration of load and boom length restrictions. This was evidenced by a sample of SL's crane scheme and during discussions with project personnel. It was clear that personnel were aware of these requirements, and fully conversant with the required information and requirements to confirm safe crane setup.
- Adequate consideration of the minimisation of the staff exposed to risks during the lifts by establishment of exclusion zones. This was evidenced by the presence of a hold-point in the detailed method statement and SL confirming the lift area will be fenced with manned access control.
- Readiness for the implementation of the mitigation measures claimed for the crane power failure leading to a suspended load. This was evidenced by the lift contractor confirming they have equipment local to site that would enable temporary re-energisation of the crane on loss of power.
- Consideration of the wind loading for identified susceptible loads. This was evidenced within the crane scheme and confirmed through discussion with the lift engineer.
In addition, during the inspection, the following observations were made:
- The ventilation plant project was behind schedule and therefore not all the evidence expected to support the permissioning decision was available at the time of the inspection due to the programme slippage and I do not consider that they represent a compliance shortfall at this point in time. I have discussed this with SL and clarified that I expect these to be made available prior to ONR giving permission. I have therefore raised a Regulatory Issue to record these required actions.
- From the evidence sampled, I am satisfied that SL has followed its processes under LC22 in respect to safety assessment and implementation of operational arrangements for construction cranes on the MSSS facility.
- The Site Nuclear Safety Committee has correctly identified the risk of complacency during the review process, recognising the repetitive nature of the lifting cases being presented from the MSSS facility and has reiterated the high hazard, high consequence of the programme. I take reassurance from the fact that the NSC has recognised this potential error trap. For similar reasons I have, as part of the above regulatory issue, requested evidence of independent oversight of the lifts during the lifting period.
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.