Office for Nuclear Regulation

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Wylfa - Planned Inspection

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).and Magnox Ltd Corporate IIS.

Interventions Carried Out by ONR

Planned inspections of Licence Conditions (LCs), 22, 26, 28 and 36.

The following meetings were also undertaken:

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 planned inspections focussed on Magnox Ltd's transition at Wylfa from Generating to defueling operations. For all LCs inspected evidence was provided that gave robust demonstration of implementing changes to a good standard. Magnox Ltd has taken a very structured approach to the transition that has involved Station Operating Instructions being written specifically for the defueling operations rather than modifying the current documentation. Additionally a comprehensive review of maintenance instructions is ongoing resulting in significant improvements in accuracy, clarity and quality of documents and enhanced engagement throughout the workforce continuing to strengthen the safety culture on site.

The regulatory liaison meeting is held quarterly and coincidentally with the quarterly defueling transition oversight meeting. The meeting was attended by regulators from National Resources Wales, ONR and management team members from Wylfa. 25. There were no significant matters arising during the meeting.

A regular quarterly review of ONR regulatory issues was undertaken with the Wylfa Regulatory Liaison Officer. A number of Issues had been addressed and can be closed. Those issues that remain open are progressing in line with regulator and licensee expectations.

A meeting was held to discuss the licensee's response to a number of queries arising from ONR's examination of the Emergency Handbook supporting the amended Wylfa Emergency Plan. The discussions were productive and all queries addressed adequately with some minor amendments.

A meeting was held to discuss Magnox Ltd's proposed response to ONR's draft note setting out the current regulatory understanding regarding Fire Detection and Suppression Systems for the Trawsfynydd Fuel Element Debris (FED) retrieval project. It was agreed that an ONR Level 4 issue would be raised for an informed discussion between Magnox Ltd and ONR technical specialists.

Conclusion of Intervention

From the information obtained and evidence gathered during this intervention, I believe there were no issues identified that were considered to adversely affect nuclear safety.


Crynodeb gweitredol

Pwrpas yr Ymyriad

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).

Cynhaliwyd y gwaith yn unol â'r rhaglen archwilio a drefnwyd ar gyfer Strategaeth Ymyrraeth Integredig (IIS) yr Wylfa ac IIS Corfforedig Magnox Ltd.

Ymyraethau a Gyflawnwyd gan yr ONR

Archwiliadau wedi eu trefnu ar Amodau Trwydded (LCs), 22, 26, 28 a 36.

Cynhaliwyd y cyfarfodydd canlynol hefyd:

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

Roedd yr archwiliadau a drefnwyd yn canolbwyntio ar y trawsnewid gan Magnox Ltd yn Wylfa o Gynhyrchu i weithrediadau gwagio tanwydd. Ar gyfer pob amod trwydded a archwiliwyd darparwyd tystiolaeth oedd yn brawf cadarn o weithredu newidiadau i safon dda. Mae Magnox Ltd wedi gweithredu ymagwedd strwythuredig iawn at y trawsnewid sydd wedi cynnwys ysgrifennu Cyfarwyddiadau Gweithredu Gorsaf penodol ar gyfer y gwaith ar wagio tanwydd yn hytrach nac addasu dogfennaeth gyfredol. Yn ogystal mae adolygiad cynhwysfawr ar gyfarwyddiadau cynnal a chadw yn parhau gan arwain at welliannau sylweddol yng nghywirdeb, eglurder ac ansawdd dogfennau a gwell ymgysylltu rhwng y gweithlu cyfan yn parhau i gryfhau diwylliant diogelwch ar y safle.

Cynhelir y cyfarfod cyswllt rheoleiddiol bob chwarter ac mae'n cyd-ddigwydd gyda'r cyfarfod trosolwg chwarterol ar wagio tanwydd. Mynychwyd y cyfarfod gan reoleiddwyr o Gyfoeth Natruiol Cymru, yr ONR ac aelodau tîm rheoli'r Wylfa. 25. Ni chododd unrhyw faterion sylweddol yn ystod y cyfarfod.

Cynhaliwyd adolygiad chwarterol rheolaidd ar faterion rheoleiddiol yr ONR gyda Swyddog Cyswllt Rheoleiddiol yr Wylfa. Roedd nifer o Faterion wedi eu datrys a gellir felly eu dirwyn i ben. Mae'r materion hynny sy'n dal dan ystyriaeth yn symud ymlaen yn unol â disgwyliadau'r rheoleiddiwr a'r trwyddedai.

Cynhaliwyd cyfarfod i drafod ymateb y trwyddedai i nifer o ymholiadau yn codi o archwiliad yr ONR o'r Llawlyfr Argyfwng sy'n ategu Cynllun Argyfwng diwygiedig yr Wylfa. Bu'r trafodaethau yn gynhyrchiol a deliwyd â phob ymholiad yn ddigonol gyda rhai newidiadau bach.

Cynhaliwyd cyfarfod i drafod ymateb arfaethedig Magnox Ltd i nodyn drafft yr ONR sy'n nodi'r ddealltwriaeth reoleiddiol gyfredol ynghylch Systemau Canfod Tân ac Atal ar gyfer y prosiect adfer Gweddillion Elfennau Tanwydd (FED)Trawsfynydd. Cytunwyd i godi mater ar Lefel 4 yr ONR er mwyn cael trafodaeth hyddysg rhwng Magnox Ltd ac arbenigwyr technegol yr ONR.

Casgliad yr Ymyrraeth

O'r wybodaeth a gafwyd a'r dystiolaeth a gasglwyd yn ystod yr ymyrraeth hon, credaf na chanfyddwyd unrhyw faterion yr ystyriwyd eu bod yn cael effaith andwyol ar ddiogelwch niwclear.