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Planned intervention at Wylfa licensed site, undertaken as part of a series of planned interventions outlined in ONR Integrated Intervention Strategy (IIS) Plan Wylfa Power Station 2015/16

Executive summary

Purpose of intervention

Planned intervention at Magnox Ltd.’s Wylfa licensed site, undertaken as part of a series of planned interventions outlined in the ONR Integrated Intervention Strategy (IIS) Plan Wylfa Power Station 2015/16.

Interventions Carried Out by ONR

A comprehensive team inspection was undertaken jointly with Wylfa EHS&Q Oversight. The objectives of the inspection were to obtain a regulatory view of the adequacy of training and management of personnel competence, and to confirm the implementation of Magnox Ltd.’s Human Resource Information System, Agresso, at the Wylfa site.

The inspection sampled the arrangements for LC 10, 12 and 26, and their implementation, in the Maintenance and Fuel Operations functions at the site.

An unplanned inspection into Magnox Ltd.’s implementation of a Category 2 modification to install electrical/mechanical interlocks on the gas turbine engine cell CO2 fire protection system was undertaken.

Routine liaison meetings were held to review progress against a number of site projects, regulatory issues and ONR permissioning activities.

Explanation of Judgement if Safety System Not Judged to be Adequate

Not applicable.

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

With regard to Wylfa based SQEP assessment and subsequent demonstration, the site’s arrangements and their implementation is broadly considered to be of a good standard, particularly local SQEP matrices and focussed attention given by team leaders. A small sample of DAP arrangements concludes that documented process and evidence supporting appointments to maintenance posts could be improved to provide better demonstration of compliance. Consequently, an IIS rating of 3 – adequate is assigned to the LC 10, 12 and 26 inspection.

With regard to the implementation of the Category 2 modification relating to gas turbine engine cell CO2 interlocks, demonstrable compliance with site arrangements is evident, with a comprehensive record of implementation of the modification. Inspection of the plant provided demonstration of successful modification and evidence that adequate training of the operators had been provided with regard to the changes.

It was noted that Magnox Ltd. has not yet progressed provision of CO2 monitoring despite proposals for improvements. ONR advised that this matter should be addressed with some urgency or mitigation implemented in the meantime to ensure risks to employees remain reduced SFAIRP.

Liaison meetings covered the following topics:

During the SBI follow up meeting on lifting/dropped loads, it was confirmed that the dropped load safety case requirements for lifting in the areas around minimum safety related plant (MSRP) were not correctly implemented for the Emergency Boiler Feed system. It was agreed that a level 3 issue would be raised by ONR, with supporting actions to deliver improvements. Based on this, it was agreed that an IIS rating (ONR-DFW-IR-15-061) for LC24 of 4 (below standard) should be assigned to the rating outstanding from the inspection undertaken during the previous visit.

For each of the other topics, suitable responses by either Magnox Ltd. or ONR were identified to progress matters adequately.

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

Conclusion of Intervention

From the evidence obtained during this intervention, no matters have been identified that are likely to have a significant impact on nuclear safety on the station at this time.


Diben yr Ymyrraeth

Ymyrraeth a gynlluniwyd ar safle trwyddedig Wylfa Magnox Ltd, a gyflawnwyd yn rhan o gyfred o ymyraethau a gynlluniwyd a amlinellir yng Nghynllun Strategaeth Ymyrraeth Integredig (IIS) yr ONR Gorsaf Bŵer Wylfa 2015/16

Ymyraethau a Gyflawnwyd gan yr ONR

Cyflawnwyd archwiliad tîm cynhwysfawr ar y cyd gyda Throsolwg EHS&Q Wylfa. Amcanion yr archwiliad oedd i sicrhau barn reoleiddiol o ddigonolrwydd hyfforddiant a rheolaeth o gymhwyster personél, ac i gadarnhau gweithrediad System Wybodaeth Adnoddau Dynol Magnox Ltd, Agresso, ar safle Wylfa.

Samplodd yr archwiliad y trefniadau ar gyfer LC 10, 12 a 26, a'u gweithrediad, yn swyddogaethau Cynnal a Chadw a Gweithrediadau Tanwydd y safle.

Cyflawnwyd archwiliad na gynlluniwyd o weithrediad Magnox Ltd o addasiad Categori 2 i osod cloeon rhyngol trydanol/mecanyddol ar system diogelwch tân CO2 y gell injan y tyrbin nwy.

Cynhaliwyd cyfarfodydd cyswllt rheolaidd i adolygu cynnydd yn erbyn nifer o brosiectau safle, materion rheoleiddiol a gweithgareddau caniatâd ONR.

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

Ddim yn berthnasol.

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

Parthed asesiad SQEP yn Wylfa a dangosiad dilynol, ystyrir bod trefniadau'r safle a'u gweithrediad yn gyffredinol o safon dda, yn arbennig matricsau SQEP a sylw penodol a roddir gan arweinwyr tîm. Mae sampl bychan o drefniadau DAP yn casglu y gellid gwella prosesau a gofnodwyd a thystiolaeth i gefnogi penodiadau i swyddi cynnal a chadw i wella'r ddarpariaeth o brawf cydymffurfiad. O ganlyniad, rhoddir sgôr IIS o 3 – digonol ar gyfer yr archwiliad LC 10, 12 a 26.

Parthed gweithrediad addasiad Categori 2 yn ymwneud â chloeon rhyngol CO2 y gell injan tyrbin nwy, mae cydymffurfiad profadwy gyda threfniadau'r safle yn amlwg, gyda chofnod cynhwysfawr o weithrediad yr addasiad. Darparodd archwiliad o'r safle brawf o addasiad llwyddiannus a thystiolaeth y darparwyd hyfforddiant digonol o'r gweithredwyr o ran y newidiadau.

Nodwyd nad yw Magnox Ltd wedi cynyddu'r ddarpariaeth o fonitro CO2 eto er gwaethaf cynigion ar gyfer gwelliannau. Cynghorodd ONR y dylid delio â'r mater hwn ar frys neu y byddai angen gweithredu lliniaru yn y cyfamser i sicrhau bod risgiau i gyflogeion yn parhau i fod wedi eu gostwng cyn belled ag sy'n rhesymol ymarferol.

Trafododd cyfarfodydd cyswllt y pynciau canlynol:

Yn ystod y cyfarfod dilyniant SBI ar lwythi a godir/gollyngir, cadarnhawyd nad oedd y gofynion achos diogelwch llwyth a ollyngwyd ar gyfer codi yn yr ardaloedd o amgylch y gwaith cysylltiedig ag isafswm diogelwch (MSRP) wedi eu gweithredu'n briodol ar gyfer y system Porthi Boeler Argyfwng. Cytunwyd y byddai mater lefel 3 yn cael ei godi gan yr ONR, gyda chamau cefnogol i gyflawni gwelliannau. Yn seiliedig ar hyn, cytunwyd y dylid penodi sgôr IIS (ONR-DFW-IR-15-061) ar gyfer LC24 o 4 (is na'r safon) i'r sgôr sy'n weddill o'r archwiliad a gyflawnwyd yn ystod yr ymweliad blaenorol.

Ar gyfer pob un o'r pynciau eraill, nodwyd ymatebion addas gan naill ai Magnox Ltd neu ONR i gynyddu materion yn ddigonol.

Cyflawnwyd yr ymyrraeth yn unol â gofynion yr ONR yn yr ardaloedd a archwiliwyd.

Casgliad yr Ymyrraeth

O'r dystiolaeth a gasglwyd yn ystod yr ymyrraeth hwn, ni nodwyd unrhyw faterion sy'n debygol o gael effaith arwyddocaol ar ddiogelwch niwclear yn yr orsaf ar hyn o bryd.