Office for Nuclear Regulation

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Wylfa site Planned Licence Condition Compliance Inspection

Executive summary

Purpose of Intervention

This inspection was one of a series of planned inspections for the year 2017/18, which is informed by the Decommissioning, Fuel & Waste (DFW) sub-division strategy.

I undertook this inspection to examine the adequacy of Magnox Ltd.'s (MxL) arrangements and their implementation on the Wylfa site for compliance with Licence Condition (LC) 21, commissioning. I was supported by an Office for Nuclear Regulation (ONR) nuclear liabilities specialist inspector.

My intervention concentrated on the dry irradiated secondary fuel storage cell four (DSC 4) intermediate level radioactive waste (ILW) retrieval project commissioning activities. ONR has placed a regulatory hold point on the implementation of the active operation phase of this project. The inspection was also the readiness inspection for the permissioning associated with release of the regulatory hold point.

Interventions Carried Out by ONR

I undertook my inspection in four phases, which consisted of:

The ONR nuclear liabilities specialist inspector undertook a readiness inspection as part of the planned work for permissioning commencement of active operations for DSC 4 ILW retrievals. The LC 21 intervention and the readiness inspection were complementary activities.

Explanation of Judgement if Safety System Not Judged to be Adequate

Not applicable.

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

Based on the evidence examined it is my judgement that MxL is effectively implementing arrangements for complying with LC 21 at Wylfa. I identified a number of areas of good practice and a few areas where MxL could improve. For example the commissioning programme provides progressive challenge to the radiological and conventional hazards presented by the project. MxL could improve how it demonstrates appointment of staff under LC 21 (5).

Based on the findings from this inspection, the nuclear liabilities specialist inspector judged that the DSC4 facility has been commissioning appropriately and that it is in a state of readiness to safely commence ILW retrieval operations. Based on the evidence sampled, no shortfalls were identified that would prevent the release of the hold point to allow ILW retrieval operations to commence.

Conclusion of Intervention

I identified no matters that in my opinion could adversely affect nuclear safety. My findings were shared with, and accepted by the licensee.


Crynodeb Gweithredol

Roedd yr arolygiad hwn yn uno gyfres o arolygiadau a gynlluniwyd ar gyfer y flwyddyn 2017/18, sy'n cael ei llywio gan y strategaeth is-raniad Datgomisiynu, Tanwydd a Gwastraff (DFW).

Cynhaliais yr arolygiad hwn i archwilio digonolrwydd trefniadau Magnox Cyf. (MxL) a'u gweithredu ar safle Wylfa i gydymffurfio ag Amod Trwydded (LC) 21 comisiynu. Fe'm cynorthwywyd gan arolygydd arbenigol atebolrwyddau niwclear y Swyddfa dros Reoli Niwclear (ONR).

Roedd fy ymyrraeth yn canolbwyntio ar weithgareddau comisiynu prosiect adfer gwastraff ymbelydrol lefel ganolraddol cell bedair storio tanwydd (DSC 4) sych arbelydredig eilradd. Mae ONR wedi gosod pwynt atal rheoleiddio ar weithredu cyfnod gweithredu gweithredol y prosiect hwn. Roedd yr arolygiad hefyd yn arolygiad parodrwydd ar gyfer y caniatâd sy'n gysylltiedig â rhyddhau'r pwynt dal rheoleiddiol.

Ymyriadau a Wnaed gan ONR

Fe wnes i fy arolygiad mewn pedwar cam, a oedd yn cynnwys:

Ymgymerodd yr arolygydd arbenigol rhwymedigaethau niwclear ONR ag arolygiad parodrwydd fel rhan o'r gwaith a gynlluniwyd i ganiatáu cychwyn gweithrediadau gweithredol ar gyfer adferiadau DSC 4 ILW. Roedd yr ymyrraeth LC 21 a'r arolygiad parodrwydd yn weithgareddau cyflenwol.

Esboniad o'r Dyfarniad os Na Ddyfernir bod y System Ddiogelwch yn Ddigonol

Ddim yn gymwys.

Canfyddiadau allweddol, Barnau'r Arolygydd a Rhesymau am Ddyfarniadau a Wnaed

Yn seiliedig ar y dystiolaeth a archwiliwyd, fy marn i yw bod MxL yn gweithredu trefniadau effeithiol ar gyfer cydymffurfio ag LC 21 yn Wylfa. Nodais nifer o feysydd arfer da ac ychydig o feysydd lle gallai MxL wella. Er enghraifft, mae'r rhaglen gomisiynu'n darparu her gynyddol i'r peryglon radiolegol a chonfensiynol a gyflwynir gan y prosiect. Gallai MxL wella sut mae'n arddangos penodi staff o dan LC 21 (5).

Yn seiliedig ar ganfyddiadau'r arolygiad hwn, barnodd yr arolygydd arbenigol rhwymedigaethau niwclear fod y cyfleuster DSC4 wedi bod yn comisiynu'n briodol a'i fod mewn cyflwr o barodrwydd i gychwyn gweithrediadau adfer ILW yn ddiogel. Yn seiliedig ar y dystiolaeth a samplwyd, ni nodwyd unrhyw ddiffygion a fyddai'n atal rhyddhau'r pwynt dal i ganiatáu i weithrediadau adfer ILW ddechrau.

Casgliad yr Ymyrraeth

Ni wnes i nodi unrhyw faterion a allai, yn fy marn i, effeithio ar ddiogelwch niwclear. Rhannwyd fy nghasgliadau gyda'r trwyddedai, ac fe'i derbyniwyd ganddo.