Heysham 1 - Quarterly Review of ONR/LC27 Compliance Inspection System Based Inspection - SBI14 - Ponds and Flasks
- Site: Heysham 1
- IR number: 15-172
- Date: March 2016
- LC numbers: 10, 23, 24, 27, 28, 34
Purpose of intervention
The purpose of this intervention was to undertake a Licence Condition (LC) compliance inspection and a system based inspection of the ponds and flasks system at EDF 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 2015/16.
Interventions Carried Out by ONR
As part of this intervention, the ONR nominated site inspector undertook an LC27, Safety Mechanisms, Devices and Circuits (SMDCs), compliance inspection as well as a quarterly review of progress with ONR issues.
In addition the ONR nominated site inspector and a civil engineering specialist inspector performed a System Based Inspection (SBI) of the ponds and flasks system to judge the system performance against its safety function. Through examination of this system and associated sub-systems, we performed compliance inspections against Licence Condition (LC) 10 (Training), LC23 (Operating rules), LC24 (Operating instructions), LC27 (Safety mechanisms, devices and circuits), LC28 (Examination, inspection, maintenance and testing) and LC34 (Leakage and escape of radioactive material and radioactive waste). The inspections were based on sampling the implementation of the arrangements in place against each licence condition.
Explanation of Judgement if Safety System Not Judged to be Adequate
From the inspection, we judge that overall the ponds and flasks system meets the requirements of the safety case and is adequate.
Key Findings, Inspectors' Opinions and Reasons for Judgements Made
Prior to this inspection, a review was undertaken of the company LC27 procedures against the relevant ONR guidance documents for these licence conditions. I judged that these procedures provide adequate arrangements to satisfy the requirements of LC27.
In order to judge the adequacy of the implementation of these arrangements, I sampled the gas circulator system and judged that appropriate SMDCs were identified and appropriate procedures were in place to ensure that the plant is not operated, inspected, maintained or tested unless the identified SMDCs are properly connected and in good working order. On the basis of the areas sampled I judged that the station compliance with LC27 was adequate with an IIS rating of 3.
With respect to the SBI the following judgements were made;
- LC 10 (Training) – We examined the role profile and training records for a sample of the personnel involved in the operation of the ponds and flasks 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. We therefore assigned an IIS rating of 3 (adequate) to this inspection.
- LC 23 (Operating Rules) – based on our samples we concluded that suitable conditions and limits have been derived from the safety case, and are implemented through the technical specifications (Operating Rules). We considered that the technical specifications were to a good standard and that technical specification compliance was well controlled and monitored. We therefore assigned an IIS rating of 2 (good standard) to this inspection.
- LC 24 (Operating Instructions) – based on our samples we concluded that suitable Station Operating Instructions (SOI) are provided for the ponds and flasks system. Overall we considered that the operating instructions were adequate but have placed an action for the licensee to give further consideration to the appropriateness of including the stop log gates in the emergency operations SOI. Notwithstanding our comments we assigned an IIS rating of 3 (adequate) to this inspection.
- LC 27 (Safety Mechanisms, Devices and Circuits) – We sampled the Pond Package Cooling System (PPCS) for this inspection, as this is equipment that is required to be available in the event of loss of pond cooling and where the pond cooling plant cannot be restored within acceptable timescales. We confirmed that this safety critical equipment has maintenance routines specified on the maintenance schedule and verified that appropriate inspections had been carried out to confirm that the equipment was available for deployment. During our inspection we observed that the equipment was in very good condition and there were clear drawings to enable assembly and connection of the system to the back-up water supply. We identified that an additional pump functionality check is required by the maintenance schedule but this does not appear to have been completed. We have therefore raised an action for the licensee to complete this check or review this requirement. Notwithstanding this action we judged that overall the arrangements were adequate and we assigned an IIS rating of 3 (adequate) to this inspection.
- LC 28 (Examination, Inspection, Maintenance and Testing) – Although most areas sampled demonstrated adequate examination, inspection, testing and maintenance, we identified a number of areas were improvements are required. These include additional civil engineering inspections of the fuel pond structure, improvements to the recording of the pond inspections, and improvement to the inspection arrangements for the flask lid temporary chocks and the Pond Package Cooling System pump. In light of these findings we judged that compliance with LC28 was below the expected standard in the areas sampled with an IIS rating of 4 (below standard). Consequently a number of actions have been raised on the station to address these findings. These will be pursued via the ONR Issues database under a single issue 4301.
- LC 34 (Leak and Escape of Radioactive Material and Radioactive Waste) –Although most areas sampled demonstrated adequate maintenance, we noted that the identification and subsequent sentencing of potential signs of leakage is not adequately recorded. We therefore judge that the compliance with LC34 is below the expected standard and an IIS rating of 4 (below standard) has been assigned. An appropriate action has been placed on the station to address this shortfall and recorded under ONR issue 4301.
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
On the basis of the areas sampled it was judged that the station compliance with LC27 was adequate with an IIS rating of 3.
Following the system based inspection of the ponds and flasks we judged that compliance with LC23 was good with and IIS rating of 2, compliance with LC10, 24 and LC27 was adequate with an IIS rating of 3 and compliance with LC28 and LC34 was below standard. Notwithstanding this, after considering all the evidence examined during the inspections we considered that the ponds and flasks system met the requirements of the safety case.