The purpose of this intervention was to undertake a system based inspection of the ponds and flasks system at EDF Nuclear Generation Limited’s (NGL’s) Heysham 2 power station in line with the planned inspection programme contained in the Heysham 2 Integrated Intervention Strategy (IIS) for 2015/16.
As part of this intervention, the ONR Nominated Site Inspector and two Civil Engineering Specialist Inspectors 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 Conditions LC10 (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.
From the inspection, we judge that overall the Ponds and Flasks system meets the requirements of the safety case and is adequate.
During the course of the system inspection it was found that Heysham 2 has adequate arrangements to ensure that the Ponds and Flask system is maintained and operated in accordance with the safety case and the station’s arrangements, based on the areas sampled by the inspection. The inspection identified a specific maintenance concern which has given rise to a single issue which has been entered on to the ONR Issues Database. A number of areas for potential improvement have also been identified and, although none gave rise to significant concern, NGL has agreed to follow them up in accordance with their own arrangements. ONR will monitor their progress through routine regulatory business.
In summary, the outcome from the SBI of the Ponds and Flask system is that the arrangements and the implementation for LC 10 was given an inspection rating 2 (good). The implementation for LC’s 23, 24, 27 & 34 were deemed to be adequate and therefore we have given an inspection rating 3 (adequate).
With respect to LC28 an IIS rating of 4 (below standard) was given. Although most areas sampled demonstrated adequate maintenance, the civil engineering inspections of the fuel pond structure are not carried out in sufficient detail and therefore they are below the expected standard. ONR issue 3876 has been raised to address this shortfall and it will be pursued as part of normal business.
The intervention was performed in line with ONR’s guidance requirements (as described in our technical inspection guides) in the areas inspected.
After considering all the evidence examined during the sample inspections undertaken against LCs 10, 23, 24, 27, 28 and 34, we considered that the Ponds and Flasks system met the requirements of the safety case.