- Site: AWE Aldermaston
- IR number: 21-102
- Date: November 2021
- LC numbers: 28
Executive summary
Purpose of intervention
This intervention, conducted at the Atomic Weapons Establishment (AWE) Aldermaston licensed site, was undertaken as part of the 2021/22 intervention plan and weapons sub-division strategy.
Interventions Carried Out by ONR
Accompanied by an Office for Nuclear Regulation (ONR) specialist mechanical engineering inspector and the lead Environment Agency (EA) environmental inspector for AWE, I conducted a planned Licence Condition LC 28 (“Examination, Inspection, Maintenance and Testing”, referred to as EMIT by AWE) inspection in the former production facility within UTC at AWE Aldermaston. The focus of the LC 28 inspection was on maintenance, inspection etc. of the active ventilation systems installed in the former UTC production facility.
[Note – in Section 1 of my report I will refer to this joint ONR/EA inspection team as “we”].
The intervention was performed in line with ONR's guidance requirements (as described in our technical inspection guides) in the areas inspected.
In addition, I held a routine (monthly) ‘Keep in Touch’ (KIT) meeting with key members of the former production facility’s management team, to discuss progress with key safety related projects, to follow up on safety related events in UTC etc. and I also attended the planned bi-monthly Fissile Level 3 Regulatory Interface Meeting (RIM).
Explanation of Judgement if Safety System Not Judged to be Adequate
Not applicable.
Key Findings, Inspector's Opinions and Reasons for Judgements Made
Whilst the licensee (i.e. AWE Plc) explained that the former production facility continues to operate to a safety case that pre-dates its 2nd Periodic Review of Safety (PRS2), submitted to ONR in 2016, and is in the process of implementing a modern standards safety case (its Facility Safety Justification, FSJ – submitted to ONR in 2021), from the information sampled we noted the following adverse findings:-
- Checks on the condition of ventilation ductwork within the former production facility are visual only and we questioned whether this continued to be appropriate, as the licensee has no extant knowledge as to the internal condition of the ductwork, which has now been in service for several decades.
- Definition of ‘pass’/’fail’ criteria on maintenance Job Cards requires significant improvement and the implementation of new Maintenance Instructions (MI) as a part of FSJ implementation presents a valuable opportunity to deliver these required improvements.
- A maintenance instruction sampled relating to the checking of air flow directions in the facility was in our opinion overly complicated and sampling of a completed Job Card indicated a possible lack of adequate understanding on the part of the maintainer who had last completed the task.
- A recent INF1 was raised with respect to two highly corroded bolts during inspection of one of the former production facility’s stacks. However, previous inspection reports revealed that corrosion had been identified on the structure and although Job Cards were raised to address the finding, these appeared to have been closed off without appropriate action having been taken.
- It was our opinion that when adverse conditions are encountered during the conduct of EMIT work, the licensee’s response in terms of considering resultant amendments to the EMIT requirements going forward could be improved.
- Housekeeping in the ventilation plant rooms visited still needs some attention and we questioned whether adequate consideration had been given to tolerable roof loadings as a number of redundant fan motors awaiting disposal appear to be concentrated in one area of one of the plant room.
Conclusion of Intervention
Due to the findings summarised above and from the totality of the evidence sampled and from our discussions with facility personnel, the overall LC 28 inspection was awarded a rating of ‘Amber’ and two Regulatory Issues are to be drafted and agreed with the licensee to ensure the adverse findings are addressed to ONR’s satisfaction and in a timely manner.
In the case of all the routine meetings I conducted with key licensee personnel (reported in the body of this report), no matters were identified as requiring additional regulatory attention.