Office for Nuclear Regulation

Hunterston B planned intervention

Executive summary

Purpose of intervention

The purpose of this intervention was to undertake a System Based Inspection (SBI 012) on the Fuelling Machine at EdF Nuclear Generation Ltd (NGL’s) Hunterston B power station in line with the planned inspection programme contained in the Hunterston Integrated Intervention Strategy (IIS) for 2015/16.

Interventions Carried Out by ONR

A system based inspection of the Fuelling Machine was undertaken by an ONR Control and Instrumentation (C&I) Specialist Inspector and a Mechanical Handling Technical Specialist from AMEC Foster Wheeler.  The aim of the inspection was to confirm the adequacy of the implementation of the safety case with respect to the fuelling machine against the following LC’s:

I undertook a compliance inspection against Training. Inspection of training is a routine and explicit component of system based inspections undertaken on the station on at least five occasions per year. I focussed this inspection on:

An examination of the most recent quarterly training health report submitted to the station management;

An examination of output from the recent re-accreditation of the station’s eight operations training programmes from the Training Standards Accreditation board (TSAB);

An observation of a training course delivered to maintenance technicians as part of the station’s human performance improvement programme;

A review of the station’s strategy to ensure recruitment via the station ‘pipeline’ are trained to the necessary rigour, particularly in light of current and anticipated levels of staff attrition.

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 – the system was judged to be adequate.

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

From the system based inspection on the Fuel Machine we made the following observations and judgements:

LC 10 (Training) – We examined the role profile and training records for a sample of the personnel involved in the operation and maintenance of the Fuelling Machine. These included the Fuelling Machine System Engineer, a Duly Authorised Person (DAP), a Fuelling Machine Operator and various Maintenance Technicians. The evidence provided identified the post and training profile for each role and the relevant training program description and we found all essential training to be in date. All role and training information requested was readily made available indicating the electronic database where the records are held (SAP) is working efficiently. We judged that the LC 10 element of this inspection merited an IIS rating of 3 – Adequate.

LC 23 (Operating Rules) – The licensee’s Operating Rules (OR) are defined within its Technical Specifications (TSs).  The TSs contain a number of required ‘surveillances’ (e.g. for refuelling) which are conducted on the station via the relevant check sheet. Compliance with the ORs was demonstrated by viewing an example of the Refuelling Check Sheets for On/Off Load Refuelling which are populated and signed by SQEP as a task is carried out. The populated ‘wet signed’ check sheets are held for future reference in long term storage following completion of the task.  We judged that the LC 23 element of this inspection merited an IIS rating of 3 – Adequate.

LC 24 (Operating Instructions) – The Operating Instructions for the Fuelling Machine are in the form of check sheets relevant to each task. We selected the Refuelling Check Sheets for On/Off Load Refuelling to review. A hard copy of the check sheets was reviewed and there was a clear link from the requirements of the TS to the tasks on the check sheets. Station personnel showed good knowledge of the system explaining the check sheets are a live document populated for each task. We judged that the LC 24 element of this inspection merited an IIS rating of 3 – Adequate.

LC 27 (Safety Mechanisms, Devices and Circuits) – We reviewed the Calibration of two safety mechanisms. We examined the links back to the requirements of the safety case and forward to the implementation of the safety mechanisms on station. Accordingly, we examined the maintenance requirements and records for both items, finding these to be in order. We judged that the LC 27 element of this inspection merited an IIS rating of 3 – Adequate.

LC 28 (Examination, Inspection, Maintenance and Testing) – We selected a number of items of equipment from the maintenance schedule relevant to nuclear safety.  Satisfactory evidence was obtained to confirm all selected maintenance tasks had been completed in accordance with the requirements of the maintenance schedule.

Independent reports of thorough examination were sampled to verify compliance with the Pressure Systems Safety Regulations (PSSR) and the Lifting Operations and Lifting Equipment Regulations (LOLER). Both were in date and showed the work had been carried out and recorded by independent and competent persons. There were no defects or areas of advice identified. We judged that the LC 28 element of this inspection merited an IIS rating of 3 – Adequate.

LC 34 (Leakage and Escape of Radioactive Material and Radioactive Waste) – We investigated the pressure vessel containment boundary as relevant to LC 34. The current PSSR report was provided which demonstrates the Fuelling Machine is maintained in accordance with PSSR requirements. PSSR and test results were readily available for review and demonstrated the tests were carried out and approved by SQEP individuals. We judged that the LC 34 element of the inspection merited an IIS rating of 3 – Adequate.

From an LC10 perspective, I judged that the station has mature and rigorous processes through which to continually review effectiveness of training programmes and processes. The external validation by TSAB of operations programmes is a noteworthy endorsement. There are some gaps to excellence and ongoing challenges to secure a workforce of the right calibre and experience for the remaining generating lifetime; in my opinion the station is on the right course. Accordingly, I have allocated an IIS rating of 2 – Good Standard.

Conclusion of Intervention

After consideration of all the evidence witnessed during the sampling inspections undertaken against LCs 10, 23, 24, 27, 28 and 34, we consider that the arrangements and their implementation, associated with the Fuelling Machine, meet the requirements of the safety case and are deemed adequate.

A number of observations were made as a result of the inspection and these were brought to the attention of the licensee, who readily undertook to address the findings within timescales we judged to be appropriate.  However, there were no findings from this inspection that could significantly undermine nuclear safety and accordingly no issues were raised during the inspection.