- Site: Sellafield
- IR number: 21-155
- Date: January 2022
- LC numbers: 10, 23, 24, 27, 28, 34
Executive summary
Purpose of Intervention
The Office for Nuclear Regulation (ONR) undertakes all regulatory interactions with the Sellafield site licensee (Sellafield Ltd.) against a strategy defined by the ONR Sellafield subdivision.
In accordance with that strategy, two inspections were undertaken within Analytical Services on the Sellafield site:
- A system-based inspection (SBI) to form a view on the adequacy of the implementation of the nuclear ventilation system safety case within Analytical Services and to gain assurance that the safety system fulfils its safety function.
- A Licence Condition (LC) 23 (Operating Rules), LC 24 (Operating Instructions) and Licence Condition (LC) 28 (Examination, inspection, maintenance and testing) compliance inspection to gain confidence that Analytical Services are compliant with these licence conditions specifically in relation to nuclear fire safety.
Interventions Carried Out by ONR
From the 18 – 20 of January 2022, two planned inspections were carried out of Analytical Services utilising specialists from the following technical disciplines:
- Radiological Protection (RP)
- Fault Studies (FS)
- Mechanical Engineering (ME)
- Internal Hazards (IH)
The inspections were conducted in line with a plan shared with Sellafield Ltd. ahead of the inspection (2021/75008).
The system-based inspection of the ventilation system was undertaken on 18th and 19th of January 2022. In order to determine the adequacy of the licensee’s implementation of the safety case claims in respect of this system, evidence to verify the adequacy of the implementation of Sellafield Ltd.’s arrangements for six pre-defined licence conditions (LCs) (as listed below) was examined. These LCs have been selected in view of their importance to nuclear safety and are defined within ONR’s formal process for SBIs.
- LC 10 – Training (NS-TAST-GD-027)
- LC 23 – Operating Rules (NS-INSP-GD-023)
- LC 24 – Operating Instructions (NS-INSP-GD-024)
- LC 27 – Safety Mechanisms, Devices and Circuits (NS-INSP-GD-027)
- LC 28 – Examination, Inspection, Maintenance and Testing (NS-INSP-GD-028)
- LC34 – Leakage and Escape of Radioactive Material and Radioactive Waste (NS-INSP-GD-034)
The compliance inspection was undertaken on 20th of January 2022 to assess Analytical Services’ compliance with Sellafield Ltd.’s corporate arrangements for LC 23 (Operating Rules), LC 24 (Operating Instructions) and LC 28 (Examination, inspection, maintenance and testing) specifically in relation to nuclear fire safety.
The inspections involved reviewing the applicable claims in the safety cases and sampling suitable evidence to determine compliance against the selected LCs. This was achieved through a combination of document reviews, plant inspections and discussions with operators and maintenance staff.
Explanation of Judgement if Safety System Not Judged to be Adequate
The safety system is judged to be adequate.
Key Findings, Inspector's Opinions and Reasons for Judgements Made
Assurance was provided that Sellafield Ltd. Analytical Services understands what the requirements are in terms of compliance with the identified LCs and that the Sellafield Ltd. corporate arrangements are being appropriately complied with. No significant matters were identified as requiring immediate regulatory attention.
The representatives of the licensee had an effective understanding of the requirements of these Licence Conditions, and of the site arrangements for its implementation.
Since the inspection activities undertaken relating to Operating Rules during the SBI of the nuclear ventilation system were relevant to nuclear fire safety, Operating Rules were not discussed further during the nuclear fire safety compliance inspection and no rating was assigned against this licence condition for that inspection.
Conclusion of Intervention
From the evidence sampled during the inspection, Sellafield Ltd. has adequately implemented the nuclear ventilation safety case in Analytical Services and are following the Sellafield Ltd. arrangements for LCs 10, 23, 24, 27, 28 and 34 and the nuclear ventilation system adequately fulfils the required safety function as claimed in the safety case. For this system based inspection a rating of GREEN - No formal action is appropriate. However, a shortfall was identified related to retention of maintenance records resulting in a Level 4 regulatory issue being raised.
Sellafield Ltd. has also effectively implemented its arrangements for compliance with LCs 24 and LC 28 specifically in relation to nuclear fire safety and inspection ratings of GREEN - No formal action is considered to be appropriate.