Executive summary
Date(s) of inspection:
January 2026
Aim of inspection
The Medium Active Salt Free Evaporator (MASFE) facility is key to the continued high hazard risk reduction program at Sellafield and is one of the sources of the greatest risk at the facility. ONR has been receiving a regular number of MSML challenges for MASFE and it has not been inspected for four years. During the last inspection, this area received Amber ratings against LC 24 and LC28. This inspection is to seek assurance that the implementation of the safety case is successful, that the facility is in compliance with Sellafield Limited internal arrangements for LC24 and LC28 and that ONR can have confidence that MASFE and the pipebridge will be available for years to come.
Subject(s) of inspection
- LC10 - Training - Rating: GREEN
- LC24 - Operating instructions - Rating: GREEN
- LC27 - Safety mechanisms, devices and circuits - Rating: GREEN
- LC28 - Examination, inspection, maintenance and testing - Rating: AMBER
- LC34 - Leakage and escape of radioactive material and radioactive waste - Rating: GREEN
Key findings, inspector's opinions and reasons for judgement made
This was a system based inspection (SBI) of the Medium Active Salt Free Evaporator (MASFE) and associated pipe bridge at the Thermal Oxide Reprocessing Plant (THORP) at the Sellafield Site. I was supported by specialist inspectors, and we undertook a plant walkdown and sampled evidence to support compliance with the safety case for the six licence conditions associated with SBIs.
For five of the licence conditions (LCs) (LC10 (Training), LC23 (Operating rules), LC24 (Operating Instructions), LC27 (Safety devices, mechanisms and circuits) and LC34 (Leakage and escape of radioactive material and radioactive waste) I was satisfied that Sellafield Ltd is compliant with the LCs and has implemented its safety case.
However, for one of the LCs (LC28 (Examination, inspection, maintenance and testing (EIMT)) I was not satisfied that THORP was compliant with the expectations of the licence conditions.
For LC28 I found that although THORP has overall implemented the EIMT requirements required by the safety case, improvement is required. Although the internals of the first 15 metres of the 500 metre pipebridge has been examined with a remote drone, THORP was unable to demonstrate that it has an adequate inspection regime for the remainder of pipework carrying radioactive material within the pipe bridge.
Overall, I am satisfied that THORP has implemented its safety case but will seek improvement to address the shortfalls identified through appropriate enforcement and Regulatory Issues.
Conclusion
Having reviewed the evidence provided by THORP, I am satisfied that for LC10, LC23, LC24, LC27 and LC34 a Green (no formal action) rating is appropriate.
For LC28, I found that for safety related equipment, THORP was able to demonstrate that it had been maintained. However THORP was unable to evidence that it had adequately completed the two-yearly inspection for the pipework and liner and THORP was unable to demonstrate that it had an adequate inspection programme in place. In addition, I did not find evidence that THORP had observed the damage to the upper concrete section joints. I therefore rate the LC28 element of this inspection as Amber (seek improvement).
Overall, I am satisfied that THORP has implemented its safety case but will seek improvement to address the shortfalls identified through appropriate enforcement and Regulatory Issues.