This intervention at the Atomic Weapons Establishment (AWE) Aldermaston licensed site was undertaken as part of the 2016/17 intervention plan and weapons sub-programme strategy.
As part of the intervention we sampled AWE Aldermaston’s licence condition 22 arrangements for modifications. The targeted areas were decommissioning and Higher Activity Waste (HAW) drum storage facilities. We were provided with AWEs new licence condition arrangements before the inspection and sampled the Asset Change (AC) process.
Not applicable during this intervention.
Based on the evidence obtained by sampling in the areas inspected (AC process, visit to decommissioning and HAW drum storage facilities) AWE has demonstrated control and oversight of modifications being made to existing plant.
Modifications are categorised by conventional, environmental, explosives, nuclear and radiological hazard groups. The overall category is determined by the highest assessed hazard in any of the hazard groups.
The ACR database tracks all modifications and is overseen by the Configuration Manager (CM). The Asset Change Board (ACB) has oversight of ACR contents, actions and statistics.
Modifications link to the safety case through the Asset Change Request (ACR) stakeholders, ACB and the approval route.
A selection of ACRs (those open and raised in last 12 months) was sampled during the site walkdown, with evidence that modifications are being adequately controlled. Closed out or cancelled ACRs had an appropriate level of sign off and, where sampled, the correct documentation linked to them through the database.
Advice was provided to AWE to consider formalising a local process to provide the CM with a scanned copy of an accepted ACR once it is signed by stakeholders. This would prevent (as occurred during the inspection) the paperwork being unavailable due to annual leave or sickness of the ACM, and mitigate against loss of the paperwork.
During the site walkdown, we discussed appropriate levels of safety justification needed to demonstrate that decommissioning operations are ALARP.
Licence Condition 22 - Modification or experiment on existing plant: Based on the evidence sampled during the inspection, the ONR inspectors concluded that AWE Aldermaston are compliant with LC22 and that No Formal Action is required. Minor findings will be followed up by the site inspector as part of normal regulatory business.