- Site: Hinkley Point B
- IR number: 19-004
- Date: April 2019
- LC numbers: 28
Executive summary
Purpose of Intervention
This intervention report covers a planned inspection performed as part of an ONR Operating Facilities Division intervention applicable to EDF Energy Nuclear Generation Ltd (EDF NGL) during the 2019 statutory outage of Reactor 3 (R3) at Hinkley Point B (HPB) power station. The focus of this inspection was to inspect a sample of outage work activities carried out in relation to control and instrumentation (C&I) equipment and systems important to nuclear safety in order to confirm that they remain fit for their intended purpose at HPB.
Interventions Carried Out by ONR
The inspection and assessment covered by this intervention report was undertaken in support of ONR’s 2018/19 statutory outage inspection programme. The inspection included a sample review of the HPB R3 2019 statutory outage activities carried out in relation to C&I equipment and systems important to nuclear safety. It also covered EDF NGL’s arrangements for compliance with Licence Condition (LC) 28 (Examination, inspection, maintenance and testing (EIMT). The findings of this inspection will contribute to ONR’s regulatory decision to grant Consent to the return of R3 to normal operating service in accordance with LC 30 (Periodic shutdown).
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
Not applicable.
Key Findings, Inspector's Opinions and Reasons for Judgements Made
This inspection has found that the commitments made in the Outage Intentions Document for the HPB R3/TA7 2019 statutory outage (HINB/R/MOZ/345, Rev 000, CM 2018/365395) have been satisfied in relation to the sampled C&I equipment and systems important to nuclear safety.
During the inspection, we found the following areas of good practice.
- We noted that the station acted proactively in replacing some of the 20 year old devices with “like-for-like” models from the same manufacturer to manage ageing issues.
- An event in October 2018 resulted in a number of auto control loops tripping to manual and a thermal power reduction in R3. The station undertook an investigation and was unable to identify the root cause. However, the station acted proactively and identified two possible causes that were traced to the auto control loops tripping to manual. In addition, during this outage, the station has made arrangements to reduce the potential for electromagnetic and radio frequency interference (EMI/RFI) of this system as a precautionary response.
- In one of our sample inspections, we noted that the station referenced the previous outage test sheets (2016) to compare the test outcomes from this outage for the same devices. This station informed us that this is part of their normal arrangement for maintenance.
- The station has assigned a dedicated person to ensure contractors are aware of the rules about taking electronic devices to site, and made arrangements to ensure electronic devices are checked before entering the site.
However, we also found areas for improvement. There are some Work Order Cards/Work Instructions that currently do not require records to be taken when an adjustment is made. Two actions were raised in this regard:
- The station to consider adding “as found” and “as left” test results for each device/component in the work instruction, as appropriate,
- The station to add a clause to the work instruction to adjust the device to the specified set-point and record any adjustments needed. Or, provide a justification as to why this is not considered necessary.
These actions have been captured in the Regulatory Issues database number 7143 to allow ONR to monitor progress through normal regulatory business. These actions do not affect the return to service of R3.
As maintenance work is still on-going, we raised a number of requests for copies of further maintenance records when the work is completed. The HPB’s Reactor 3 return to service is not dependent on the supply of this information.
Based on our sample inspection of the C&I aspects of the HPB R3 2019 statutory outage, we have assigned an intervention rating of Green to LC 28 compliance.
Conclusion of Intervention
From the evidence gathered during this inspection of a sample of HPB R3 2019 statutory outage C&I activities, we have not identified any C&I issues that could lead to a detrimental impact on nuclear safety or prevent ONR issuing a “Consent” to allow R3 to restart. This is subject to the completion of the planned EIMT activities and the completion of any emergent work. Therefore, from a C&I perspective, we recommend that support be given for a Consent to allow R3 to return to normal operating service.