Office for Nuclear Regulation

Atomic Weapons Establishment Aldermaston – Inspection ID: 52611

Executive summary

Date(s) of inspection:

  • August 2023

Aim of inspection

The aim of this intervention is to ensure the licensee has fit-for-purpose arrangements for the management of radioactive waste, including storage and minimisation, and confirm compliance with licence conditions 4 (Restrictions on Nuclear Matter on the Site) and 32 (Accumulation of Radioactive Waste) within the DU Research Facilities.

The inspection is focussed on the management of radioactive waste arising from the facility’s operations with particular focus on the management of chemicals, redundant equipment and wastes accumulated for longer than 12 months.

Subject(s) of inspection

  • LC 04 – Restrictions on nuclear matter on the site – Rating: GREEN
  • LC 32 – Accumulation of radioactive waste – Rating: GREEN

Key findings, inspector’s opinions and reasons for judgement made

In accordance with the Office for Nuclear Regulation’s (ONR) 2023/24 weapons sub-division strategy for the Aldermaston licenced site (AWE plc.), and considering the the Key Regulatory Objectives (specifically KRO.4) and Key Sub-Divisional Objectives (specifically KSO.2), a planned Licence Condition (LC) 4 (Restrictions on nuclear matter on the site) and LC 32 (Accumulation of radioactive waste) compliance inspection was carried out in AWE’s Depleted Uranium (DU) Research Laboratories. The inspection focussed on the management of radioactive waste arising from the facility’s operations, in particular the management of chemicals, redundant equipment and wastes accumulated for longer than 12 months.

The inspection sought evidence of adequate arrangements and their implementation through discussions with AWE staff, a review of records and documentation relevant to LCs 4 and 32, and a plant visit in order to make judgements of compliance against regulatory expectations. To form effective regulatory judgements on AWE’s compliance, the regulatory expectations detailed within ONR’s Technical Inspection Guides (TIG) NS-INSP-GD-004 ‘LC4: Restrictions on nuclear matter on the site’ and NS-INSP-GD-032 ‘LC32: Accumulation of Radioactive Waste’ were considered.

Overall, based on the sample inspected, I judge that AWE’s DU Research Laboratories have generally met regulatory expectations with respect to the storage and management of radioactive waste. The facility has made good progress in reducing the amount of legacy waste chemicals and the use of AWE’s Special Operations Group (SOG) has resulted in good progress made in the reduction of redundant equipment and legacy items within the facility. However, I have identified the following areas where further work is required to meet regulatory expectations and to ensure that the facility avoids more significant issues in the future. Progress to address these will be tracked through the regulatory issues process:

  • The plant visit identified a number of shortfalls related to a lack of inventories, labelling, storage limits and conditions, and proportionate temporary waste laydown area controls.
  • The Workplace Risk Assessment should more widely consider the storage of radioactive waste items within the facility.
  • Absence of an options assessment for the management, size reduction and disposal of large, non-operational waste items.

There is no justification to underpin the continued use of the Water Wentgate Quench Furnace tank to store approximately 1000 litres of radioactively contaminated water.

The potentially radioactively contaminated asbestos waste items are inadequately stored within ISO containers in the A100.1 yard and their condition is unknown.

No matters requiring immediate regulatory attention were identified during this inspection. Whilst a number of shortfalls have been identified, I am satisfied that AWE DU Research Facilities are adequately managing their operational wastes and are making progress with minimising their legacy waste items. After considering the quantities and type of material used in the facility the overall risks in managing the radioactive wastes are low and the shortfalls are not considered to be significant. I therefore consider, noting the ONR guidance on inspection ratings, that an inspection rating of ‘Green (no formal action)’ is merited.

Conclusion

On the basis of evidence sampled during the inspection, I judge that AWE plc. are adequately managing their operational wastes and are making progress reducing the number of accumulated waste items within the A*/A* facility. The facility is broadly compliant with the requirements of LC 4 (Restrictions on nuclear matter on the site) and LC 32 (Accumulation of radioactive waste) and after considering the quantities and type of material used in the facility, the overall risks in managing the radioactive wastes are low and the shortfalls are not considered to be significant. I consider that an inspection rating of Green (no further action) is merited for both licence conditions.

I observed a number of shortfalls in relation to the following aspects of storage and management of radioactive waste:

  • The plant visit identified a number of shortfalls related to a lack of inventories, labelling, storage limits and conditions, and proportionate temporary waste laydown area controls.
  • The Workplace Risk Assessment should more widely consider the storage of radioactive waste items within the facility.
  • Absence of an options assessment for the management, size reduction and disposal of large, non-operational waste items.
  • There is no justification to underpin the continued use of the Water Wentgate Quench Furnace tank to store approximately 1000 litres of radioactively contaminated water.
  • The potentially radioactively contaminated asbestos waste items are inadequately stored within ISO containers in the A100.1 yard and their condition is unknown.

I have proposed a Level 4 regulatory issue to track the licensee’s progress in addressing these shortfalls.