Office for Nuclear Regulation

Torness Power Station - System Based Inspection - SBI 14 - Ponds and Flasks

Executive summary

Purpose of intervention

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) Torness power station in line with the planned inspection programme contained in the Torness Integrated Intervention Strategy (IIS) for 2015/16.

Interventions Carried Out by ONR

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.

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

Based on the areas sampled during the course of the system inspection, it was found that Torness has adequate arrangements to ensure that the ponds and flasks system meets the requirements of the safety case.   

In summary, the outcome from the System Based Inspection of the Ponds and Flasks system is that the arrangements and the implementation for LC 10, 23, 24, 27 & 34 were deemed to be adequate and therefore we have given an inspection rating of 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. This inspection concern has given rise to a single issue which has been entered onto the ONR Issues Database in order for ONR to track EDF-NGL’s progress with the implementation of a more robust inspection regime. 

In addition, a number of areas for potential improvement have also been identified and, although none gave rise to significant concern, EDF-NGL has agreed to follow them up in accordance with their own arrangements.

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

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.

ONR Issue Number 3955 was raised to address specific maintenance and inspection shortfalls which have given rise to 2 actions within this Intervention Record.

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 Torness power station as set out in the Integrated Intervention Strategy, which will continue as planned.