Office for Nuclear Regulation

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Wylfa Power Station - Planned Intervention

Executive summary

Purpose of intervention

This was a planned inspection of Magnox Ltd’s Wylfa power station, undertaken as part of the planned intervention strategy for the Decommissioning, Fuel and Waste (DFW) Programme of the Office for Nuclear Regulation (ONR).

The work was carried out in line with the planned inspection programme contained in the Wylfa Integrated Intervention Strategy (IIS).

Interventions Carried Out by ONR

Planned inspections of Licence Condition 11 and 24.

In addition to the inspections identified above a number of liaison meetings were attended to monitor progress with current activities and maintain awareness of any matters of regulatory interest. These included the following topics:

Explanation of Judgement if Safety System Not Judged to be Adequate

No safety system based inspections were undertaken during this intervention.

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

The intervention was performed in line with ONR’s guidance requirements (as described in our technical inspection guides) in the areas inspected.

The Licence Condition 11 inspection focussed on sampling how Magnox Ltd  train, coach and develop emergency role personnel and was undertaken through observation of the delivery of a shift exercise. The aim of the shift exercise was to develop and train the proposed site emergency arrangements for defueling operations. Overall the training exercise was delivered and key elements of learning for implementation of these arrangements were identified. The exercise was well planned and prepared. It is unfortunate that the direction of the exercise drifted due to lack of umpire action but discussions with Wylfa’s emergency planning engineer confirms this can be addressed and managed for future exercises.It is considered that implementation of training for emergency arrangements is adequate.

Magnox Ltd provided an overview of its arrangements for compliance with LC24 operating instructions and demonstrated that they met relevant QMS requirements, were current and responsibility allocated. A Wylfa Plant Item Operating Instruction (PIOI) and associated Plant Item Maintenance Instruction (PIMI) was selected at random and used as a basis for inspecting the implementation of Magnox Ltd’s arrangements. Some opportunities to ensure consistency between PIMI and PIOI limits and conditions were identified, which can be addressed as part of ongoing improvement programmes for conduct of operations and maintenance.  In the areas inspected Magnox Ltd demonstrated an adequate standard of compliance with the requirements of LC24.

The scope of a recent ONR enforcement letter regarding the need for improvements in the conduct of maintenance at Wylfa, including procedural quality, use and adherence was excluded from the LC24 inspection as this issue is subject to an improvement programme currently being addressed Magnox Ltd.

The liaison meetings undertaken provided useful updates on matters of regulatory interest and confirmed adequate progress being made by Magnox Ltd in delivering against the topics discussed.

Conclusion of Intervention

There are no findings from this inspection that could significantly undermine nuclear safety and no change to the planned interventions and inspections of Wylfa power station is required.


Crynodeb gweithredol

Diben yr Ymyrraeth

Roedd hwn yn arolygiad cynllunedig o orsaf bŵer Wylfa Magnox Cyf., yr ymgymerwyd ag ef fel rhan o’r strategaeth ymyriadau cynllunedig ar gyfer Rhaglen Ddatgomisiynu, Tanwydd a Gwastraff  (DFW) y Swyddfa dros Reoli Niwclear (ONR).

Gwnaed y gwaith yn unol â’r rhaglen arolygiadau cynllunedig a gynhwysir yn Strategaeth Ymyriadau Integredig Wylfa. (IIS).

Ymyriadau a Wnaed gan ONR

Ymyriadau cynllunedig o Amodau Trwyddded 11 a 24.

Yn ogystal â’r arolygiadau a nodir uchod mynychwyd cyfarfod cyswllt rheoleiddiol er mwyn monitro cynnydd â gweithgareddau cyfredol a chynnal ymwybyddiaeth o unrhyw faterion o ddiddordeb rheoleiddiol. Roedd y rhain yn cynnwys y pynciau dilynol:

Esboniad o’r Dyfarniad os Bernir Nad yw’r System yn Ddigonol

Ni wnaed unrhyw arolygiadau seiliedig ar system ddiogelwch yn ystod yr ymyrraeth.

Canfyddiadau Allweddol, Barnau’r Arolygydd a Rhesymau am Ddyfarniadau a Wnaed

Gwnaed yr ymyrraeth yn unol â gofynion cyfarwyddyd ONR (fel y’u disgrifir yn ein canllawiau arolygiad technegol), y gellir eu gweld yn www.onr.org.uk/operational/tech_insp_guides/index.htm yn y meysydd a arolygwyd.

Fe wnaeth yr arolygiad Amod Trwydded 11 ganolbwyntio ar sut mae Magnox Cyf. yn hyfforddi, cyfarwyddo a datblygu personél rôl argyfwng ac fe’i wnaed trwy arsylwi ar gyflenwad ymarfer sifft. Nod yr ymarfer sifft oedd datblygu a hyfforddi trefniadau argyfwng arfaethedig y safle ar gyfer gweithrediadau dat-lenwi. Ar y cyfan cyflenwyd yr ymarfer hyfforddi a nodwyd elfennau allweddol dysgu ar gyfer gweithredu’r trefniadau hyn. Roedd yr ymarfer wedi’i chynllunio a pharatoi’n dda. Mae’n anffodus bod cyfeiriad yr ymarfer wedi gwyro oherwydd diffyg gweithredu gan ddyfarnwr ond mae trafodaethau â pheiriannydd cynllunio argyfwng Wylfa’n cadarnhau y gellir mynd i’r afael â hyn a’i reoli ar gyfer ymarferion y dyfodol. Ystyrir bod gweithrediad hyfforddiant ar gyfer trefniadau argyfwng yn ddigonol.

Fe wnaeth Magnox Cyf. ddarparu trosolwg o’i drefniadau ar gyfer cydymffurfio â chyfarwyddiadau gweithredu LC24 gan arddangos eu bod yn diwallu gofynion QMS perthnasol, eu bod yn gyfredol a’u bod wedi’u dyrannu’n gyfrifol. Dewiswyd Cyfarwyddyd Gweithredu Eitem Offer Wylfa (PIOI) a Chyfarwyddyd Cynnal a Chadw Eitem Offer (PIMI ) cysylltiedig ar hap ac fe’u defnyddiwyd fel sylfaen ar gyfer archwilio gweithrediad trefniadau Magnox Cyf. Nodwyd rhai cyfleoedd i sicrhau cysondeb rhwng terfynau PIMI a PIOI, y gellir eu trafod fel rhan o raglenni gwella parhaol ar gyfer cynnal gweithrediadau a chynnal a chadw. Yn y meysydd a arolygwyd fe wnaeth Magnox Cyf. Arddangos saon ddigonol o gydymffurfiad â gofynion LC LC24.

Roedd cwmpas llythyr gorfodi ONR diweddar ynghylch yr angen am welliannau o ran trefnu cynnal a chadw yn Wylfa, gan gynnwys ansawdd, defnydd ac ymlyniad gweithdrefnol, wedi’i gau allan o’r arolygiad LC24 gan fod y mater hwn yn amodol ar raglen wella sy’n cael ei thrafod ar hyn o bryd gan Magnox Cyf.

Fe wnaeth y cyfarfodydd cyswllt yr ymgymerwyd â hwy ddarparu diweddariadau defnyddiol ar faterion o ddiddordeb rheoleiddiol gan gadarnhau bod cynnydd digonol yn cael ei wneud gan Magnox Cyf. o ran cyflenwi yn ôl y pynciau a drafodwyd.

Casgliad yr Ymyrraeth

Nid oes unrhyw ganfyddiadau o’r arolygiad hwn a allai dtanseilio diogelwch niwclear yn sylweddol ac nid yw unrhyw newid i ymyriadau ac arolygiadau gorsaf bŵer Wylfa yn ofynnol.