Office for Nuclear Regulation

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Trawsfynydd Decommissioning Site – Level 1 Exercise

Executive summary

Purpose of intervention

This report describes an inspection of Magnox Ltd's Trawsfynydd licensed site, undertaken as part of a series of routine interventions set out in the Integrated Intervention Strategy document.

Interventions Carried Out by ONR

During the intervention I carried out compliance inspections on:

Explanation of Judgement if Safety System Not Judged to be Adequate

This intervention did not include a safety system based inspection.

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

ONR has recently approved a revised version of the on-site emergency plan for the Trawsfynydd site.  The compliance inspection for LC 11 focussed on the implementation of the revised emergency plan through the sub-ordinate site emergency handbook.  An adequate standard of implementation was verified along with some minor opportunities to improve the clarity and referencing of the preserved local off-site monitoring capability and to improve the focus the site emergency exercise programme.

The compliance inspection for LC12 established that the training and authorisation management system was able to demonstrate that all Magnox persons requiring authorisation as ‘suitably qualified persons’ and ‘duly authorised persons’ were in date.  A sample of contractor records showed that individuals had received training in their roles and were appropriately authorised to perform work that may affect safety.  Whilst an adequate standard of compliance was confirmed for LC12, an opportunity for improvement was identified for Magnox to demonstrate that there is pre-agreed training and competence criteria for contractors working on the site.

The compliance inspection for LC 26 showed that there was an adequate standard of supervision being applied to operations that may affect safety on site. 

I engaged with the site on its progress against various improvement opportunities identified during previous compliance inspections and noted that a progress had been made in several areas of regulatory interest.

Conclusion of Intervention

In the areas I considered during the intervention I found that the implementation of the arrangements for compliance with licence conditions 11, 12 and 26 was to an adequate standard.  A number of actions for improvement will be clarified and agreed with the Trawsfynydd site.

Crynodeb gweithredol

Diben yr Ymyrraeth

Mae'r adroddiad hwn yn disgrifio archwiliad o safle trwyddedig Magnox Ltd Trawsfynydd, a gyflawnwyd yn rhan o gyfres o ymyraethau cyffredinol a sefydlir yn y ddogfen Strategaeth Ymyrraeth Integredig.

Ymyraethau a Gyflawnwyd gan yr ONR

Yn ystod yr ymyrraeth, fe gyflawnais archwiliadau cydymffurfiad ar:

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

Nid oedd yr ymyrraeth hon yn cynnwys archwiliad yn seiliedig ar systemau diogelwch.

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

Mae'r ONR wedi cymeradwyo fersiwn ddiwygiedig yn ddiweddar o gynllun argyfwng ar y safle ar gyfer safle Trawsfynydd.  Canolbwyntiodd yr archwiliad cydymffurfio ar gyfer LC 11 ar weithredu'r cynllun argyfwng diwygiedig trwy'r llawlyfr argyfwng safle darostyngol.  Gwriwyd safon weithredu ddigonol ynghyd a rhai cyfleoedd i wella eglurder a chyfeirio galluedd monitro oddi ar y safle lleol gwarchodedig ac i wella ffocws y rhaglen ymarfer argyfwng safle.

Sefydlodd yr archwiliad cydymffurfiad ar gyfer LC12 bod y system reoli hyfforddiant ac awdurdodiad yn gallu arddangos fod holl bersonau Magnox oedd angen awdurdodiad yn 'bersonau gyda chymwysterau addas' a 'phersonau gydag awdurdodiad priodol' yn gyfredol.  Dangosodd sampl o gofnodion contractwyr fod unigolion wedi dderbyn hyfforddiant yn eu rolau ac wedi eu hawdurdodi'n briodol i gyflawni gwaith a allai effeithio ar ddiogelwch.  Er y cadarnhawyd safon ddigonol o gydymffurfiad ar gyfer LC12, nodwyd cyfle ar gyfer gwelliant i Magnox arddangos fod yna feini prawf hyfforddiant a chymhwyster a gytunwyd o flaen llaw ar gyfer contractwyr yn gweithio ar y safle.

 Dangosodd yr archwiliad cydymffurfiad ar gyfer LC 26 fod yna safon ddigonol o oruchwyliaeth yn cael ei weithredu i weithrediadau a allai effeithio ar ddiogelwch ar y safle. 

Fe ymgysylltais gyda'r safle ar ei gynnydd yn erbyn amrywiol gyfleoedd gwelliant a nodwyd yn ystod archwiliadau cydymffurfiad blaenorol a nodi y cafwyd cynnydd mewn sawl maes o ddiddordeb rheoleiddiol.

Casgliad yr Ymyrraeth

Yn y meysydd a ystyriwyd gennyf yn ystod yr ymyrraeth, gwelais fod gweithrediad y trefniadau ar gyfer cydymffurfiad gydag amodau trwyddedu 11, 12 a 26 i safon ddigonol.  Bydd nifer o gamau ar gyfer gwelliant yn cael eu hegluro a chytuno gyda safle Trawsfynydd.