Hunterston B planned intervention
- Site: Hunterston B
- IR number: 15-083
- Date: September 2015
- LC numbers: 32, 34
Purpose of intervention
The purpose of this intervention was to undertake Licence Condition [LC] compliance inspections at EDF Energy Nuclear Generation Ltd’s [NGL’s] Hunterston B power station, in line with the planned inspection programme contained in the Hunterston B Integrated Intervention Strategy [IIS] for 2015/16.
Interventions Carried Out by ONR
This intervention included compliance inspections against the following Licence Conditions:
- LC32 – Accumulation of radioactive waste
- LC34 – Leakage and escape of radioactive material and radioactive waste
In addition I attended an annual meeting with the SEPA inspector to discuss matters of mutual regulatory interest. I also observed a workshop led by NGL to review its nuclear safety requirements [NSRs] and re-draft as part of an ongoing ONR review into regulation under LC23(4).
Explanation of Judgement if Safety System Not Judged to be Adequate
No system inspection was undertaken during this intervention
Key Findings, Inspector's Opinions and Reasons for Judgements Made
The LC32 compliance inspection was undertaken jointly with the SEPA inspector. During the inspection we:
- Examined the station’s progress towards improving its radioactive waste focus index [RWFI] over the past 12 months. It is evident that the station’s performance in this area has dipped since the start of 2015. I was provided with satisfactory evidence that the station has put in place an appropriate recovery plan as a result of enhanced attention on low level waste disposals during the forthcoming statutory outage and optimisation of existing disposal routes.
- Examined the station’s safety case for interim but time-limited storage of discrete items of intermediate level waste [ILW] which does not meet current acceptance criteria at Low Level Waste Repository (LLWR). We were satisfied that appropriate safety case justification has now been completed under the station’s LC22 arrangements and that satisfactory condition monitoring regime has been implemented.
- Examined the station’s plans for disposal of more difficult waste streams such as metallic waste, ILW dessicant and tritiated oils. The forthcoming variation in discharge authorisation that SEPA is currently assessing will increase the flexibility to plan and execute disposal. The pace of metallic waste disposal to a third party company in Germany, through a brokering arrangement with LLWR, is slower than the station would like. We advised the station to ensure communications with LLWR from the fleet are pitched at the right level to ensure hold ups are managed where practicable.
- Visited the active effluent treatment plant and waste store. We were satisfied with the overall condition of plant and observed continued evidence of investment from the station
During the LC34 compliance inspection I made the following observations and judgements:
- The station has made less progress than expected towards implementation of new company arrangements for compliance with LC34. There have been some delays in implementing engineering reviews as required by the arrangements; I was provided appropriate assurance that the requisite inspections are now planned.
- The station has yet to differentiate radioactive leaks as a specific category of leak in its asset management system, as required by its company arrangements. In this respect the station has not specifically categorised any leaks as meeting ‘radioactive’ criteria since the arrangements were introduced during 2014, outwith the approach undertaken by the other seven stations in the fleet.
- I was satisfied however that, notwithstanding the absence of specific categorisation, the station has a proven and appropriate process for prioritising leaks for management and rectification according to nuclear safety significance of the leak. However, I emphasised to the station the importance of complying with its arrangements and in the interests of compliance with LC34(2) and the duty therein to specifically notify , record, investigate and report in accordance with arrangements under LC7.
- I observed progress against observation made during the 2014 inspection and was satisfied in each case that appropriate progress has been made.
The intervention was performed in line with ONR’s guidance requirements (as described in our technical inspection guides) in the areas inspected.
Conclusion of Intervention
In light of the recent recovery in the RWFI metric and ongoing careful management of low level waste stocks, I have allocated an IIS rating of 3 – Adequate for LC32.
In light of continued delays in fully implementing the company arrangements under LC34, I have allocated an IIS rating of 4 – Below standard. A Level 4 regulatory issue has been raised accordingly to record and manage progress towards resolution.
There are no findings from this inspection that could significantly undermine nuclear safety. It is also judged that no additional regulatory action is needed over and above the planned interventions of the Hunterston B power station as set out in the Integrated Intervention Strategy, which will continue as planned.