Office for Nuclear Regulation

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Magnox Ltd – 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 Conditions 7, (Incidents on the site), 35 (Decommissioning) and 36 (Organisational capability).

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 topic:

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 7 inspection was undertaken by an ONR Inspector from the Regulatory Intelligence team within ONR. The inspection addressed both the traditional compliance inspection and a benchmarking inspection that considers the level of compliance against similar inspections at other licensed sites. The inspection focussed on operational experience accumulated during the past 12 months. It was concluded that compliance with the requirements for LC7 was adequate; however some elements of the benchmarking inspection identified potential opportunities for improvements in comparison with other licensed sites.

Magnox Ltd is currently undertaking a company review of its decommissioning strategy and programmes on a site by site basis with the intention of developing revised Life Time Plans (LTPs). Examination of the current LTP and sampling a specific task demonstrated that the information expected to be available within the decommissioning strategy and plans was consistent with ONR guidance. The inspection established that arrangements are in place to meet the expectations of Licence Condition 35 and that the licensee is broadly compliant with them. There has been an agreement with ONR that the LTP and decommissioning milestones agreed with ONR previously, may be misaligned for a short period while the LTP review process is completed. On this basis, it was concluded that the current arrangements and their implementation was adequate.

Magnox Ltd has introduced new corporate arrangements for compliance with LC36 that have been implemented at all Magnox sites with the exception of Wylfa. Implementation of these revised arrangements at Wylfa requires a withdrawal of the ONR approval of the extant LC 36 arrangements.  Consequently, the inspection focussed on how that change is being managed. Some opportunities for improvement in aspects of the site’s implementation of the revised arrangements were identified, however these were not considered to be significant. Based on the inspection findings it was concluded that the Licence Condition 36 arrangements and subsequent implementation were adequate.

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

It was concluded that for the licence conditions inspected, the licensee's arrangements for compliance and their implementation were found to be adequate.  There were no findings from this inspection that could significantly undermine nuclear safety and no change to the planned intervention strategy for the Wylfa power station is required.


Crynodeb gweithredol

Diben yr Ymyrraeth

Roedd hwn yn archwiliad a gynlluniwyd o orsaf bŵer Wylfa Magnox Ltd, a gyflawnwyd yn rhan o'r strategaeth ymyrraeth a gynllunnir ar gyfer Rhaglen Datgomisiynu, Tanwydd a Gwastraff (DFW) y Swyddfa dros Reoli Niwclear (ONR).

Cyflawnwyd y gwaith yn unol â'r rhaglen archwilio a gynlluniwyd yn Strategaeth Ymyrraeth Integredig (IIS) Wylfa.

Ymyraethau a Gyflawnwyd gan yr ONR

Archwiliadau arfaethedig o Amodau Trwydded 7, (Digwyddiadau ar y safle), 35 (Datgomisiynu) a 36 (Galluedd sefydliadol).

Yn ogystal â'r archwiliadau a nodwyd uchod, mynychwyd nifer o gyfarfodydd cyswllt i fonitro cynnydd gyda gweithgareddau cyfredol a chynnal ymwybyddiaeth o unrhyw faterion o ddiddordeb rheoleiddiol. Roedd y rhain yn cynnwys y pwnc canlynol:

Esboniad o’r Dyfarniad os Nad oedd y System Ddiogelwch wedi cael ei Barnu yn Ddigonol.

Ni chyflawnwyd archwiliadau seiliedig ar system ddiogelwch yn ystod yr ymyrraeth hon.

Casgliadau Allweddol, Barnau’r Arolygydd a Rhesymau dros Wneud Dyfarniadau

Cyflawnwyd yr ymyrraeth yn unol â chanllaw ymyrraeth yr ONR ar gyfer y meysydd a archwiliwyd.  Mae hwn ar gael ar www.onr.org.uk/operational/tech_insp_guides/index.htm

Cyflawnwyd archwiliad Amod Trwyddedu 7 gan Arolygwr yr ONR o'r tîm Gwybodaeth Rheoleiddio yn yr ONR. Deliodd yr archwiliad â'r archwiliad cydymffurfiad traddodiadol ac archwiliad meincnodi sy'n ystyried y lefel o gydymffurfiad yn erbyn archwiliadau tebyg mewn safleoedd trwyddedig eraill. Canolbwyntiodd yr archwiliad ar brofiad gweithredol a gronnwyd yn ystod y 12 mis diwethaf. Casglwyd bod cydymffurfiad gyda'r gofyniad ar gyfer LC7 yn ddigonol; fodd bynnag, nododd rhai elfennau o'r archwiliad meincnodi gyfleoedd posibl ar gyfer gwelliannau o gymharu â safleoedd trwyddedig eraill.

Mae Magnox Cyf yn cyflawni adolygiad cwmni ar hyn o bryd o'i strategaeth a rhaglenni datgomisiynu ar sail fesul safle, gyda'r bwriad o ddatblygu Cynlluniau Oes (LTP) diwygiedig. Dangosodd archwiliad o'r LTP presennol a samplu o dasg benodol bod yr wybodaeth y disgwyliwyd fyddai ar gael yn y strategaeth a chynlluniau datgomisiynu yn gyson gyda chanllaw'r ONR. Sefydlodd yr archwiliad bod y trefniadau yn barod i fodloni disgwyliadau Amod Trwyddedu 35 a bod y trwyddedai yn cydymffurfio'n gyffredinol gyda nhw. Cafwyd trefniant gyda'r ONR y gellir camleoli'r LTP a'r cerrig milltir datgomisiynu a gytunwyd yn flaenorol gyda'r ONR am gyfnod byr, tra bod y broses adolygu LTP yn cael ei chwblhau. Ar sail hyn, casglwyd bod y trefniadau presennol a'u gweithrediad yn ddigonol.

Mae Magnox Cyf wedi cyflwyno trefniadau corfforaethol newydd ar gyfer cydymffurfiad gyda LC36 sydd wedi eu gweithredu ym mhob un o safleoedd Magnox heblaw Wylfa. Mae gweithrediad y trefniadau diwygiedig hyn yn Wylfa yn gofyn am dynnu cymeradwyaeth yr ONR yn ôl ar y trefniadau LC 36 sydd ar glawr.  O ganlyniad, canolbwyntiodd yr archwiliad ar sut mae'r newid hwnnw'n cael ei reoli. Nodwyd rhai cyfleoedd ar gyfer gwelliant mewn agweddau o weithrediad y safle o'r trefniadau diwygiedig, fodd bynnag, ni ystyriwyd y rhain i fod yn arwyddocaol. Yn seiliedig ar gasgliadau'r archwiliad, casglwyd bod y trefniadau Amodau Trwyddedu 36 a'u gweithrediad dilynol yn ddigonol.

Roedd y cyfarfodydd cyswllt a gynhaliwyd yn gyfle i gael diweddariad defnyddiol ar faterion o ddiddordeb rheoleiddio gan gadarnhau bod Magnox Ltd yn sicrhau cynnydd digonol yn erbyn y pynciau a drafodwyd.

Casgliad yr Ymyrraeth

Casglwyd ar gyfer yr amodau trwydded a archwiliwyd, bod trefniadau'r trwyddedai ar gyfer cydymffurfiad a'u gweithrediad yn ddigonol.  Nid oedd unrhyw gasgliadau o'r archwiliad hwn a allai danseilio diogelwch niwclear yn arwyddocaol, ac nid oes angen newid i'r strategaeth ymyrraeth arfaethedig ar gyfer gorsaf bŵer Niwclear.