- Site: Hinkley Point B
- Inspection ID: 51915
- Date: August 2022
- LC numbers: 23, 28
Executive summary
Purpose of inspection
ONR have been undertaking a rolling series of reactor chemistry inspections, since 2010, with the aim being to conduct a chemistry focussed inspection at each site around every 3 years.The focus of these inspections is on operational chemistry control and management.
This inspection will consider if the licensee (NGL) exercises adequate control of station chemistry at Hinkley Point B (HPB) to minimise materials degradation, radiation exposure and the generation of radioactive waste. Staff resource, competence and relevant procedures may also form part of the inspection, along with the visibility of the chemistry safety case.The inspection will also serve to sample aspects of NGL’s response to the fleet enforcement letter served following the feedwater chemistry control event at DNB.
Subject(s) of inspection
LC23 – Operating rules (Rating – Green)
LC28 – Examination, inspection, maintenance and testing (Rating – Green)
Key findings
Generation Ltd (NGL) site approximately every 3 years.The focus of these inspections is on operational chemistry control and management. This inspection was carried out jointly with the Environment Agency (in part – day 1) and specifically considered:
- technical governance implementation to station operating rules and instructions (particularly focusing on chemistry control of feedwater (off-load) and the ponds); and
- chemistry requirements, the ability to maintain the relevant plant and how plant health is assessed (with duties for end of generation considered).
I considered the following Licence Conditions (LCs) in relation topond chemistry and off-load boiler chemistry:
LC23 (Operating Rules)
I reviewed implementation of control parameters for pond chemistry and off-load boiler chemistry, identifying appropriate visibility of control parameters from technical governance in station documentation. I also sampled evidence of control of pond and off-load boiler chemistry. Station was able to demonstrate good compliance with chemistry control parameters with only minor deviations observed and adequately addressed.
Based on my sample, I was content station was controlling chemistry in line with the requirements of the safety case and I therefore judged a rating of GREEN (no formal action) to be appropriate for LC 23.
LC28 (Examination, Inspection, Maintenance and Testing)
I sampled station’s arrangements for maintaining feedwater plant availability, with focus on C42 (Condensate Polishing Plant (CPP), Make up Water Treatment Plant and Chemical Dosing) and undertook a walkdown of parts of the system. I identified relatively few defects on the system, with higher priority defects either addressed or within permitted repair timescales. I sampled maintenance records for feedwater hydrazine transfer pumps and CPP instrumentation calibration in more detail, identifying no issues. I also sampled the maintenance schedule and maintenance records relating to ponds level instrumentation in the A14 system, identifying no issues.
Based on my sample, I judged a rating of GREEN (no formal action) was therefore warranted for LC 28.
There are no findings from this inspection that could undermine nuclear safety and no change is necessary to the planned interventions and inspections at HPB.
Judgements made
Based on my sample, I was content station was controlling chemistry in line with the requirements of the safety case and I judged a rating of GREEN (no formal action) to be appropriate for LC 23. Additionally, based on my sample of maintenance records and related documentation, I considered a rating of GREEN (no formal action) was warranted for LC 28.Whilst there are no findings from this inspection that could undermine nuclear safety and no change is necessary to the planned interventions and inspections at HPB, I identified one item for follow up in routine Level 4 chemistry meetings with NGL.