Torness - SBI20 - Liquid Radwaste System
- Site: Torness
- IR number: 18-183
- Date: December 2018
- LC numbers: 10, 23, 24, 27, 28, 34
Purpose of Intervention
The purpose of this intervention was to carry out a system based inspection of the liquid radioactive waste at the EDF Energy Nuclear Generation Limited’s (NGL’s) Torness power station in line with the planned inspection programme contained in the Torness Integrated Intervention Strategy (IIS) for 2018/19.
Interventions Carried Out by ONR
The ONR nominated nuclear liabilities specialist inspectors performed a System Based Inspection (SBI) of the liquid radioactive waste system to judge the system performance against its safety function. Through examination of this system and associated sub-systems, we performed compliance inspections against the following Licence Conditions (LCs) :-
- LC 10 – Training
- LC 23 – Operating rules
- LC 24 – Operating instructions
- LC 27 – Safety mechanisms, devices and circuits
- LC 28 – Examination, inspection, maintenance and testing
- LC 34 – Leakage and escape of radioactive material and radioactive waste
The SBI was planned and led by EDF’s Independent Nuclear Assurance (INA). The Scottish Environment Protection Agency (SEPA) also took part in this intervention.
Explanation of Judgement if Safety System Not Judged to be Adequate
From the areas sampled during this inspection, we judged that overall the liquid radioactive waste system met the requirements of the safety case.
Key Findings, Inspector's Opinions and Reasons for Judgements Made
With respect to the SBI the following judgements were made;
- LC 10 (Training) – We examined the training records for a sample of the personnel involved in the operation of the liquid radioactive waste system and sampled the relevant student work book. This demonstrated that the training requirements specified for the role profiles had been completed and that the relevant training was in date. We therefore assign an IIS rating of green for LC10 compliance.
- LC 23 (Operating Rules) – Based on the evidence sampled, we concluded that the limits and conditions identified within the safety case had been implemented in an adequate manner. A shortfall was identified regarding clarification on the action to be taken on receipt of an alarm in the AETP control room; however this is considered a minor shortfall and will be captured on the station action tracking system and followed up by INA. Compliance with LC 23 is generally consistent with ONR expectations and hence we assign a rating of green.
- LC 24 (Operating Instructions) – We sampled a number of procedures associated with the operation and maintenance of the system. In addition, an operator provided an overview of some of the operations associated with the AETP control panel. Based on the evidence sampled, we concluded that the operating instructions provided to the personnel operating the system were appropriate to ensure that operations that could affect safety are adequately controlled. We therefore assign an IIS rating of green for LC24
- LC 27 (Safety Mechanisms, Devices and Circuits) – We selected a number of plant items which were stated as being relevant to the prevention and mitigation of faults identified within the Radioactive Waste Safety case for the AETP and confirmed that they were on the maintenance schedule and were adequately maintained. We judged that, overall, compliance with LC 27 meets ONR expectations and hence assign a rating of green.
- LC 28 (Examination, Inspection, Maintenance and Testing) – Based on the evidence sampled, we concluded that maintenance was being completed in line with the requirements of the maintenance schedule and by persons in roles required to be suitably qualified and experienced. There were a number of minor shortfalls identified which will be captured by the INA report related to this inspection, and raised on the station action tracking system. Notwithstanding these issues, compliance with LC28 is considered to be generally consistent with recognised good practice and therefore an inspection rating of green is assigned.
- LC 34 (Leak and Escape of Radioactive Material and Radioactive Waste) – Based on the evidence sampled and the plant walk-down, we conclude that suitable and sufficient systems are in place to ensure adequate control and containment of radioactive material and radioactive waste and therefore an inspection rating of green is assigned to LC34 compliance.
The system based inspection was planned, prepared and led by the EDF’s Independent Nuclear Assurance (INA), the minor shortfalls identified will captured within the INA report and the actions to address the shortfalls will be raised with the stations action management system. We consider that there was thorough preparation work carried out by INA, and INA provided a robust challenge to the station during the inspection.
The site inspector followed up on a number of extant regulatory issues, and a recent event related to the bolts on a fuel transport flask.
Conclusion of Intervention
On the basis of this system based inspection of the liquid radioactive waste system, we judged that compliance with LC10, 23, 24, 27, 28 and LC34 met the expected standards and were rated as green. Overall, we judged that the liquid radioactive waste system met the requirements of the safety case.
There are no findings from this inspection that could significantly undermine nuclear safety. No additional regulatory action is needed over and above the planned interventions of Torness power station as set out in the Integrated Intervention Strategy, which will continue as planned.