I undertook a system based inspection of the ventilation system serving the Berkeley intermediate level waste (ILW) vaults. This inspection was to confirm that the requirements of the safety case for the system were adequately reflected in the arrangements in place, demonstrating compliance with selected licence conditions.
The ventilation system was selected for inspection as Berkeley is preparing to retrieve ILW from the vaults and transfer it to ductile cast iron containers (DCICs) for interim storage. The work will, by necessity disturb the vault contents and increases the likelihood of radioactive dust being created, and it is important that the ventilation system operates effectively to safely confine the dust. Any dust must be controlled and collected by the ventilation system filters before it can enter the general environment. Berkeley provided me with the safety case for the ventilation system and explained how it had been incorporated into the design of the ventilation system. I inspected the vault building and was shown the modules in place through which the waste will be moved. Berkeley staff and their contractors explained how the licence conditions took into account the safety case and I examined documentation which demonstrated this.
During the visit I held a meeting with the site’s safety representatives to discuss their work in maintaining and improving safety. I discussed with Berkeley management their work programme for the coming months that and discussed the best approach to ensure interactions between the site and ONR work effectively.
The vaults ventilation safety system was judged adequate.
I believe Berkeley continues to work in a way that minimises the risks to health and safety when moving the waste currently stored in the vaults into passively safe storage in DCICs. I came to this judgement following Berkeley’s demonstration of how the safety case for ventilation during vault emptying was being implemented and supported by operational and maintenance documentation. I observed a high standard of manufacture and installation applied to the ventilation system.
Berkeley demonstrated that they were minimising the risks to the public, workers and the environment in their preparations for emptying the ILW vaults by using the ventilation system to ensure radioactive material will be filtered out of the air passing through the vault waste retrieval system.