TWG-NPPIC, May 2009, Vienna: UK status1 Current status of NPP I&C in the United Kingdom T P Smyth AMEC, Knutsford, Cheshire, UK 22 nd Meeting of the Technical Working Group on Nuclear Power Plant Instrumentation and Control, May 2009, Vienna

TWG-NPPIC, May 2009, Vienna: UK status 2 Current status of NPP I&C in the United Kingdom Nuclear Power Plants in the UK Status of I&C at nuclear plants  Reactor Protection Systems  Data Processing Systems  Refuelling machines Status of regulatory environment affecting I&C Recommendations

TWG-NPPIC, May 2009, Vienna: UK status 3 Nuclear Power Plants in the UK (1) x 610 MWeAGR Hinkley Point B x 605 MWeAGR Hunterston B Expected shutdown Start operation Unit capacityTypeReactors MWeTotal (19)‏ x 1196 MWePWR Sizewell B x 625 MWeAGR Torness x 615 MWeAGR Heysham x 615 MWeAGR Heysham x 595 MWeAGR Hartlepool x 545 MWeAGR Dungeness B x 490 MWeMagnox Wylfa x 217 MWeMagnox Oldbury

TWG-NPPIC, May 2009, Vienna: UK status 4 Nuclear Power Plants in the UK (2) ‏  Electricity sources 19% nuclear 36% gas 38% coal  Need to plan for energy replacement 7 plants will close in next 9 years 14 reactors 7359 MWe 13% of electricity sources North Sea oil and gas will be limited in future  New build Generic Design Assessment (AP1000, EPR) Target completion of GDAs June 2011 Sites identified

TWG-NPPIC, May 2009, Vienna: UK status 5 AGR : Reactor Protection Systems (1) ‏ Neoprene insulation degradation  Magnox Oldbury power station  Degradation with age Perishing Sweating Hygroscopic Becomes conductive - resistance < 1 MΏ  Stray currents in sensitive circuits Thermocouple amplifiers

TWG-NPPIC, May 2009, Vienna: UK status 6 AGR : Reactor Protection Systems (2) ‏ Neoprene insulation degradation ‏

TWG-NPPIC, May 2009, Vienna: UK status 7 AGR : Reactor Protection Systems (3) ‏ Neoprene insulation degradation

TWG-NPPIC, May 2009, Vienna: UK status 8 AGR : Reactor Protection Systems (4) ‏ Neoprene insulation degradation  Survey of all safety equipment Presence of neoprene State of neoprene Circuit function  Replacement equipment at older stations Obsolescent anyway  Repairs at newer stations Heysham 2 / Torness  6 years work, 1 more year to finalise all equipment  Prioritised by susceptibility

TWG-NPPIC, May 2009, Vienna: UK status 9 AGR : Reactor Protection Systems (5) ‏ Neutron Flux measurement systems  AGR detectors located in core at 8 locations High temperatures  Detector spares Wide range detector – integral cable Manufacturing spares – re-establishing production processes Currently a batch of 10 in progress  Electronic units Neoprene Repairs at Heysham 2 / Torness Replacement at other stations

TWG-NPPIC, May 2009, Vienna: UK status 10 AGR : Data Processing Systems  Safety claims on equipment Some reactor control functions Some alarms  Hinkley Point B New DPS installed (1999)‏  Dungeness B New DPS being installed Control / equipment protection functions segregated Ready for works testing  Other AGR's Stabilization of equipment  Adequate spares provision / hardware support.  Improved air conditioning Heysham 2: specification phase

TWG-NPPIC, May 2009, Vienna: UK status 11 AGR : Refuelling Machines  Online refuelling Stringent safety requirements  Equipment obsolescence Key focus at present  Heysham 2 / Torness Replacement of Reypac controllers with Siemens S7  I/O replaced, emulates original equipment  Reypac controller replacement  Software reverse engineered and ported  Safety functions partitioned  Successful implementation, scope of replacement expanded.  Safety standards Modern standards considered when replacing equipment

TWG-NPPIC, May 2009, Vienna: UK status 12 Regulatory Environment (1) ‏  Standards hierarchy NII SAPs and TAGs ( IAEA standards IEC standards  IEC Modern standards reviews  Design, Operation and Maintenance  Part of Periodic Safety Reviews  PSA based assessment Target / year  Limit of reliability claims for software based systems Assume 1 demand / year /demand Require diverse protection to make up /demand

TWG-NPPIC, May 2009, Vienna: UK status 13 Regulatory Environment (2) ‏  Application to Sizewell B Primary Protection System  Four channels, 2 out of 4 tripping  Software based  Production excellence  IEC  Independent confidence building  Extensive testing  Independent code safety assessment Secondary Protection System  Four channels, 2 out of 4 tripping  Protection for frequent faults  Laddic – magnetic amplifiers  Diverse technology

TWG-NPPIC, May 2009, Vienna: UK status 14 Regulatory Environment (3) ‏ New build  In general, same regulatory requirements as Sizewell B Diversity requirements in reactor protection systems Possibly less onerous protection system targets  Passively safe systems will make fewer demands  Smart Instruments Regulator considering application to nuclear facilities Assessment of evidence Plant owner collaboration  Shared qualification and licensing assessments  SIL1  No fieldbus

TWG-NPPIC, May 2009, Vienna: UK status 15 Recommendations IAEA topics  Estimating and extending life of I&C equipment to address ageing and obsolescence  Supporting the evaluation, acceptance and licensing of digital I&C system  Lessons learned from I&C project implementation and guidance for modernisation and new plant project