Magnox Ltd Oldbury nuclear licensed site planned system based inspection
- Site: Oldbury
- IR number: 17-116
- Date: September 2017
- LC numbers: 10, 23, 24, 27, 28
Purpose of Intervention
We undertook a system based inspection (SBI) of Oldbury's Pond decommissioning project. This was one of a series of planned inspections for 2017/18 in accordance with the Decommissioning Fuel and Waste sub-division strategy.
We met two of Oldbury's Site TU Safety Representatives.
The inspection and meetings with the Pond, waste management and decommissioning staff were used to familiarise the new ONR nominated site inspector with the decommissioning work being undertaken by Magnox Ltd on the Oldbury site.
Interventions Carried Out by ONR
We undertook an SBI, which considered the interaction between the Oldbury management and the Magnox Ltd Pond Project team in their preparations to remove intermediate level waste (ILW) items from the Pond. The interaction was assessed against the requirements of the six licence conditions attached to the nuclear site licence addressing:
- The safety cases for operations in the building;
- Training of staff;
- The operating rules and operating instructions arising from the safety cases;
- Safety mechanisms that would mitigate incidents in the building;
- Maintenance of equipment in the building; and
- Control and containment of radioactive waste in the building.
Explanation of Judgement if Safety System Not Judged to be Adequate
From the discussions we held, the inspection of Pond decommissioning and the information provided by the site and the waste management project team, we concluded that the interface between the site's operational staff and the Pond Project team was being managed adequately.
Key Findings, Inspector's Opinions and Reasons for Judgements Made
We found that:
- Training, LC10, was adequate for the operators undertaking the Pond Project. We looked at the preparatory work to install and commission equipment to remove ILW cartridges and filters from the Pond for long-term storage in MOSAIK ductile cast iron containers (DCICs). We found evidence that training needs had been assessed against staff experience and, where there were shortfalls, training was planned as part of the plant commissioning work.
- Safety cases and their operating rules, LC23, were applied adequately. For example, we found the project team understood the safety case needs, which will lead to identification of operating rules and instructions for commissioning the ILW retrieval equipment. We noted the highest risk to workers was from an examination of the MOSAIK and the training was to be used to optimise the inspection so as to minimise the radiation dose to workers. We were told that Oldbury and the project staff had used human factors expertise to optimise the work process.
- Operating instructions, LC24, were adequate. For example, we found evidence that showed operating experience when defuelling was being incorporated into the instructions for removing ILW using MOSAIKs and the new instructions were to be tested and optimised during commissioning.
- We noted there weren't any specific Safety Mechanisms, Devices and Circuits (SDMCs) including passive structures, LC27. We noted the refurbished building ventilation system was ensuring air flows in the Pond building were from clean areas to dirty areas and then on to filters before venting up the stack. As a result, if any contamination becomes airborne it should not result in escape of radioactive waste from the building.
- Maintenance, LC28, was adequate. This maintenance was sufficient to help prevent equipment failure.
- Control and containment of radioactive waste (LC 34), appeared adequate. For example, we noted the procedure for removing ILW from the Pond for long-term storage incorporated many of the features tried and tested when removing spent fuel from the pond and the differences will be addressed during the inactive and active commissioning of the plant.
Conclusion of Intervention
We concluded from our intervention that the working arrangements between the site team and the Pond Project team were adequate.