Heysham 1 Planned Intervention including System Based Inspection (SBI 20) - Liquid Waste
- Site: Heysham 1
- IR number: 16-034
- Date: May 2016
- 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) Heysham 1 power station in line with the planned inspection programme contained in the Heysham 1 Integrated Intervention Strategy (IIS) for 2016/17.
Interventions Carried Out by ONR
The ONR nominated site inspector and two 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
In addition the following key activities were also undertaken:
- Follow up inspection for radioactive waste regulatory issues 2751, 3808, 3809, 3813
- Quarterly review of the extant ONR issues
- Routine meeting with the site Independent Nuclear Assurance function
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:
- Radioactive Safety Case and LC28 System Review - We noted that the LC28 system review presented a well written assessment of the condition of the liquid radioactive waste system and makes a number of recommendations for improvements. A similar set of recommendations is also made in the radioactive waste safety case. Although some of the recommendations have been addressed, the station was unable to provide a comprehensive record that demonstrates the progress made to date against the other recommendations. Consequently an action has been placed on the station (ONR Issue 4466) to provide ONR with a progress update on these recommendations with appropriate completion timescales. This will be monitored by the site inspector through the ONR issues database.
- LC 10 (Training) - We examined the role profile and training records for a sample of the personnel involved in the operation of the liquid radioactive waste system. The evidence identified the essential training requirements for each role profile and we found that with one exception all essential training was in date. The one exception had been reviewed and the individual deemed suitable experienced and qualified to continue with his role. We therefore assigned an inspection rating of green to LC10 compliance.
- LC 23 (Operating Rules) - we reviewed the limits and conditions for the liquid radioactive system and judged, based on the evidence sampled, that suitable and sufficient conditions and limits have been derived from the safety case and implemented through the relevant environmental specifications. We therefore judged that compliance with LC 23 met ONR expectations and assigned an inspection rating of green.
- LC 24 (Operating Instructions) - We sampled a number of procedures associated with this system; discharge of tritiated water and radioactive sampling of a number of the storage tanks. Based on the evidence sampled, we concluded that the operating instructions provided to station staff were appropriate to ensure that operations that could affect safety are adequately controlled and that relevant operating rules are implemented. Accordingly we assigned an inspection rating of green for LC24 compliance.
- LC 27 (Safety Mechanisms, Devices and Circuits) - The station list of critical plant items was reviewed against the safety case requirements and environmental specifications. We judged that these critical plant items were subject to suitable and sufficient surveillance to confirm their availability and suitable arrangements were in place to log any unavailability to ensure that the plant was not operated outside of the identified safety case limits. We therefore considered that compliance with LC27 met our expectations with an inspection rating of green.
- LC 28 (Examination, Inspection, Maintenance and Testing) - We sampled the maintenance requirements associated with the tritiated water storage tank and some of the radioactive storage tanks. In the areas sampled the maintenance was being undertaken in line with the requirements of the maintenance schedule. A number of minor areas for improvement were pointed out to the licensee with respect to the quality of the maintenance records. These will be pursued as part of the wider intervention on record keeping. It was also noted that one of the previous inspections of the radioactive storage tanks appears to recommend a shorter inspection period than is currently listed on the maintenance schedule. Accordingly a formal action, ONR issue 4467, has been raised on the station to confirm what the required inspection period is. Resolution of this issue will be pursued by the site inspector. Notwithstanding these minor issues, overall compliance with LC28 was considered to meet the ONR expectations and therefore an inspection rating of green was assigned.
- LC 34 (Leak and Escape of Radioactive Material and Radioactive Waste) - Based on the evidence sampled and the plant walkdown, we concluded that suitable and sufficient systems were in place to ensure adequate control and containment of radioactive material and radioactive waste and therefore an inspection rating of green was assigned to LC34 compliance.
Following a review of the radioactive waste Regulatory Issues 2751, 3808, 3809, 3813 we judged that suitable and sufficient progress was being made to address ONR's concerns raised under these issues.
In particular it was judged that significant progress had been made with respect to the management of radioactive material stored in the decontamination workshop. In light of this and the ongoing action plan we judged that this met the requirements of ONR Issue 3813 which will be recorded as complete.
The intervention was performed in line with ONR's guidance requirements (as described in our technical inspection guides) in the areas inspected.
Conclusion of Intervention
Following the system based inspection of the liquid radioactive waste system we judged that compliance with LC10, 23, 24, 27 and LC34 met the expected standards and were rated as green. A couple of minor shortcomings were noted and will be tracked through the ONR issues database under issues 4466 and 4467 as part of normal regulatory business. Notwithstanding these minor issues, 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. At present, no additional regulatory action is needed over and above the planned interventions of Heysham 1 power station as set out in the Integrated Intervention Strategy, which will continue as planned.