Office for Nuclear Regulation

Hinkley Point B - SBI 22 inspection

Executive summary

Purpose of Intervention

The main purpose of this intervention was to conduct a system based inspection (SBI) of EDF Energy Nuclear Generation Ltd.’s (NGL) Hinkley Point B Power Station (HPB) in relation to the CO2 storage and distribution system.

This intervention was undertaken as part of a series of planned interventions that are listed in the Hinkley Point B Integrated Intervention Strategy 2018/2019. The inspections were undertaken by the ONR nominated site inspector and two ONR nuclear specialist inspectors for structural integrity, which for the purpose of this intervention report shall be referred to as “I”. 

Interventions Carried Out by ONR

I performed a safety case informed SBI of the CO2 storage and distribution system.  Through examination of these systems, compliance inspections were performed against the following Licence Conditions (LC):

The objective of the inspection was to determine whether the licensee’s arrangements were adequately implemented and in accordance with the systems’ safety case requirements.  These inspections were informed through the review of the station safety report (including supporting documents and references), discussion with station specialists, plant inspection and sampling of electronic documents and records.  During normal operations, the CO2 plant provides a supply of CO2 to the reactors and various fuel route facilities to maintain reactor pressure and to facilitate fuel route operations.  During fault conditions, the CO2 plant is part of an overall line of protection for various reactor and fuel route faults.

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, I judge that overall the CO2 storage and distribution system meets the requirements of the safety case.

Key Findings, Inspector's Opinions and Reasons for Judgements Made

Based on the areas sampled during this system based inspection, I consider that Hinkley Point B has implemented suitable arrangements to ensure that the CO2 storage and distribution 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 system was as follows:

Conclusion of Intervention

After considering all the evidence examined during the sample inspection undertaken against LCs 10, 23, 24, 27, 28 and 34 I judged that the requirements of the safety case have been adequately implemented at Hinkley Point B, with a rating of ‘Green – no formal action’ assigned against licence conditions 10, 23, 24, 27, 28 and 34.

There were no findings from this inspection that could significantly undermine nuclear safety.  However, during my inspection following two minor shortfalls were identified: