Office for Nuclear Regulation

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Harwell Planned Inspection

Executive summary

Purpose of intervention

This was a planned inspection at Magnox Limited’s (MXL’s) Harwell site, undertaken as part of the planned intervention strategy for the Harwell site for 2015/16.

Interventions Carried Out by ONR

In relation to Licence Condition 7 (LC7) “Incidents on the Site” I considered two topics.  The first was MXL’s LC7 compliance arrangements at the Harwell & Winfrith (H&W) sites.  The second was implementation of these compliance arrangements at these sites.  I selected these topics since I was not familiar with the LC7 compliance arrangements and since these compliance arrangements are important in relation to organisational learning.  I sampled learning from incidents on the H&W sites only and not learning from incidents on the other 10 MXL sites, or from incidents outside MXL.

In relation to Licence Condition 22 (LC22) “Modification or Experiment on Existing Plant” I considered three topics.  The first was MXL’s LC22 compliance arrangements at the H&W sites.  The second was the general health of the modifications/ safety case process at the H&W sites.  The third was implementation of the LC22 compliance arrangements at the Harwell B462 Complex.  I selected these topics since I was not familiar with the LC22 compliance arrangements, since I wished to gain an overview of the health of the modifications/ safety case process across the H&W sites and since the B462 Complex contains the highest hazard potential plant on the Harwell site.

The Environment Agency Harwell lead nuclear regulator and myself undertook a radioactive waste management joint Environment Agency/ ONR inspection.  In relation to Licence Conditions, this focussed on Licence Condition 32 “Accumulation of radioactive waste”, Licence Condition 33 (LC33) “Disposal of radioactive waste” and Licence Condition 34 (LC34) “Leakage and escape of radioactive material and radioactive waste”.  The part of Licence Condition 25 “operational records” dealing with records of the amount and location of all radioactive material was also considered but has not been rated.  Implementation of these LCs was inspected at the Liquid Effluent Treatment Plant (LETP) and at B220.

I held a routine meeting with MXL’s internal regulator for the Harwell & Winfrith sites.

I undertook planned information gathering, including an update on emergency arrangements matters and a discussion on Licence Condition 35 (LC35) decommissioning milestones.  Defining LC35 decommissioning milestones forms part of an ONR issue related to relicensing the H&W sites to MXL.

Explanation of Judgement if Safety System Not Judged to be Adequate

Not applicable.

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

In relation to LC7, I identified no issues with the LC7 compliance arrangements that I sampled.  In terms of implementation I identified several positive areas such as:  the support of the operational experience feedback team;  ongoing improvements to the operational feedback process to include good practices;  the introduction of learning from investigations briefing notes;  and, the effectiveness of the licensee’s self‑assessment process.  I also identified several improvement opportunities such as:  the timeliness of producing Level 2 investigation reports;  the timeliness of close out of some corrective actions;  and, limited recent work related to trending.  In all cases the improvement opportunities that I identified had been identified already by the licensee’s self-assessment processes and recorded as corrective actions by them.  Since the licensee’s corrective actions were due to be completed by the end of May 2015 I did not raise an ONR issue.  Instead I will inspect the close out evidence for these licensee corrective actions in June 2015.  Taking all these factors into account I assigned an Integrated Intervention Strategy (IIS) rating of 3 (adequate) to LC7.

In relation to LC22, I identified an existing Management System document that should be included in the LC22 compliance arrangements and a further existing Management System document that may be appropriate to be included in such a way that it applies to the more safety significant modifications.  I raised an ONR issue relating to these matters.  I concluded that the general health of the modifications/ safety case process is adequate.  I identified no issues relating to the implementation of two B462 Complex modifications sampled.  Taking all these factors into account I assigned an IIS rating of 3 (adequate) to LC22.

In relation to the LC25 element of the radioactive waste management joint Environment Agency/ ONR inspection, we identified that there is not a “golden thread” between the top level arrangements and local arrangements used to record the amount and location of all radioactive material, including nuclear fuel and radioactive waste, used, processed, stored or accumulated on the site at any time.  We also observed that a small amount of legacy radioactive waste, including some liquid radioactive waste, was not included on the LETP local spreadsheet used to record the amount and location of all radioactive material.  I raised two separate ONR issues to address these two matters.

In relation to the LC32 element of the radioactive waste management joint Environment Agency/ ONR inspection, no issues were identified relating to the arrangements.  We concluded that management of radioactive waste at both LETP and B220 was good and that at both locations, accumulation of radioactive waste was being minimised.  Taking all these factors into account I assigned an IIS rating of 2 (good standard) to LC32.

In relation to the LC33 element of the radioactive waste management joint Environment Agency/ ONR inspection, no issues were identified relating to the arrangements.  The sole purpose of this Licence Condition is to provide ONR with a power to Direct a licensee to dispose of radioactive waste from a nuclear licensed site.  As noted in ONR’s LC33 Technical Inspection Guide, “Circumstances on UK nuclear licensed sites to date have been such that ONR (nor its predecessor, the Nuclear Installations Inspectorate) has not needed to issue a Direction under LC33”.  Inspection of implementation of this Licence Condition is therefore not appropriate.  Taking all these factors into account I assigned an IIS rating of 3 (adequate) to LC33.

In relation to the LC34 element of the radioactive waste management joint Environment Agency/ ONR inspection, I raised an issue relating to arrangements in December 2014 which has now been closed.  I considered that a small amount of legacy liquid radioactive waste inspected in the LETP was being adequately stored in terms of LC34 expectations.  During a recent Environment Agency inspection of the B220 liquid effluent discharge facility it was noted that facilities appeared to be in good order and to be operating satisfactorily.  Finally, parts of the B220 Heating, Ventilation and Air Condition system inspected during the current inspection appeared to be in good order and to be operating satisfactorily.  Taking all these factors into account I assigned an IIS rating of 3 (adequate) to LC34.

In relation to my meeting with MXL’s internal regulator for the Harwell & Winfrith sites, evidence was provided of good alignment between the internal regulator’s arrangements and the “Independent Oversight.  A Nuclear Industry Good Practice Guide” published on behalf of the Nuclear Industry Safety Directors Forum.  We discussed the internal regulator’s 2015/16 programme.  I considered this to be proportionate since it has taken into consideration a number of factors identified from implementation of the 2014/15 programme, including expected major changes to organisational structure and management system and insufficient independent assessment of security arrangements.

In relation to the discussion of LC35 decommissioning milestones, I proposed three milestones relating to the Harwell site and two milestones relating to the Winfrith site.  These proposals will be subject to further development and agreement.

In relation to the other activities undertaken in this intervention, no key findings arose.

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

From the evidence gathered during this intervention, no matters have been identified that are likely to have a significant impact on nuclear safety on the site at this time.  Therefore, no additional regulator action arising from this visit is considered necessary at this time.