Office for Nuclear Regulation

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Torness Planned Intervention

Executive summary

Purpose of Intervention

Two interventions are recorded in this report. Their respective purposes were to:

These interventions form part of the planned ONR inspection programme set out in the Torness Integrated Intervention Strategy (IIS) for 2017/18.

Interventions Carried Out by ONR

For the systems-based inspection a Control and Instrumentation (C&I) Specialist Inspector, the Nominated Site Inspector and a member of NGL's Independent Nuclear Assurance (INA) performed a System Based Inspection (SBI) of the SSD equipment to judge the system performance against its safety function, which is to provide alternative means to the primary system of control rods for safe shutdown of the reactor. 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) and LC28 (Examination, inspection, maintenance and testing). LC34, which relates to leakage and escape of radioactive material and radioactive waste, was not considered applicable to the SSD system.

LC3 requires the licensee to manage any property transactions in relation to the site, such as leases or rights of access, so that it remains in control. I the nominated site inspector examined how the EDF NGL arrangements for LC3 had been applied by the site in relation to two property transactions through examination of records and interviewing staff involved.

The intervention was performed in line with ONR’s guidance requirements (as described in our technical inspection guides) in the areas inspected.

Explanation of Judgement if Safety System Not Judged to be Adequate

From the system based inspection, we judge that overall the SSD system meets the requirements of the safety case.

Key findings, inspectors' opinions and reasons for judgements made

Based on the areas sampled during this system based inspection, I consider that Torness has met its legal requirements that ensure that the SSD system is maintained and operated in accordance with the safety case and the station's arrangements.

In summary, the outcome of the SBI of the SSD system was:

We were satisfied on the basis of a sample of a range of relevant staff that Torness has implemented its arrangements for training staff with responsibilities for the specific operation and maintenance of the SSD system. We consider that, based on the evidence acquired during this intervention, that an inspection rating of Green is appropriate for LC10.

We were satisfied that the safety case conditions and limits have been identified and where necessary have been incorporated into technical specifications. During the site walk-down we noted that there was no signage indicating that the first stage or second stage equipment in the nitrogen storage plant was seismically qualified. Station undertook to confirm whether the current SSD arrangements on site are consistent with the claim for frequent seismic events. We consider that, based on the evidence acquired during this intervention, that an inspection rating of Green is appropriate for LC23.

We were satisfied that operating instructions were in place to support plant operations. We consider that, based on the evidence acquired during this intervention, that an inspection rating of Green is appropriate for LC 24-

We were satisfied that suitable and sufficient safety mechanisms, devices and circuits (LC27) were connected and in working order with identified operating limits and conditions to meet the requirements of the safety case. We consider that, based on the evidence acquired during this intervention, that an inspection rating of Green is appropriate for LC27

We also observed that the SSD system was maintained meeting the legal requirements of LC 28 and on that basis have assigned an IIS rating of green against the LC28 element of this system based inspection.

Concerning LC3, the site was able to explain using recent transactions as examples how it complied with the license requirements. However, this showed that compliance had been ensured through the Site's engineering change (LC22) arrangements rather than the company's LC3 arrangements. I have rated this element of my inspection 'green' for Torness. I consider though that the corporate LC3 arrangements do not provide for adequate oversight to ensure sustained compliance, and following discussion of this with the ONR Corporate inspector I have raised an ONR regulatory issue against the EDF NGL corporate arrangements.

In addition to the above, we undertook routine engagements at the site including, follow-up inspection activities in connection with control & instrumentation issues previously identified by the C&I Specialist Inspector, and informal interactions with INA.

Conclusion of Intervention

After considering all the evidence examined during the sample inspection undertaken against LCs 10, 23, 24, 27 and 28, we considered that the requirements of the safety case have been adequately implemented at Torness, with a rating of green assigned against licence conditions 10, 23, 24, 27 and 28.

For LC3 the evidence was that site had complied with the law and I rated the inspection 'green'.

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.