ALARA STUDIES FOR EDF NUCLEAR POWER PLANTS

2008 ISOE conference H. BERTIN EDF-UTO 2 Presentation draft 1. EDF and UTO presentation 2. From PANTHER-RP simulation tool to practical recommendations 3. The example of in-site recommendations implementation 4. Gain issued from the methodology implementation

1. A brief presentation of EDF Group and UTO

2008 ISOE conference H. BERTIN EDF-UTO 4 A brief presentation of the EDF Group  The EDF Group a leading player in the European energy industry.  EDF Group is present in all areas of the electricity value chain, from generation to trading, and active in the gas chain in Europe.  Leader in the French electricity market, the Group also has solid positions in the United Kingdom, Germany and Italy. Breakdown of EDF Group's generation worlwide * RE: Renewable Energies Installed capacity

2008 ISOE conference H. BERTIN EDF-UTO 5 UTO: a Nuclear Technical Support Unit In charge of Fleet Maintenance for EDF NPP’s (Nuclear Power Plants)

2. From PANTHER-RP simulation to practical recommandations

2008 ISOE conference H. BERTIN EDF-UTO 7 PANTHER-RP models and calculations PANTHER-RP Model Source workstation Plans et iso = 3D models Dose rates calculation for each source and for each workstation Biological Protection Radiological context Dose rate reduction coefficient calculation for each option spectrometry data, radiological map = radiological model Maintenance programm = Workstations, task duration Biological protection list = Workstations, task duration

2008 ISOE conference H. BERTIN EDF-UTO 8 An UTO recommandation example 5- shielding definition BOUCLE 1–Local R412–RCP120VP –Radiological protection option RCP120VP 12 mm lead shield in front of hot branch Lead matress 12 mm lead shield Lead matress aound RCP 120 valve

3. An implementation example

2008 ISOE conference H. BERTIN EDF-UTO 10 TRICASTIN example  The NPP has identified UTO recommendations in the logistic activities management

2008 ISOE conference H. BERTIN EDF-UTO 11 TRICASTIN example  UTO recommendations are also integrated in the shielding contractor documents RCP 120 VP valve Lead Screen gratting Hot Branch Lead matress

4. Gains

2008 ISOE conference H. BERTIN EDF-UTO 13 Gains : the integrated dose  In 2006 : radiological gains around 25 H.mSv issued from UTO recommendation implementation compared to implementation based on habits  An optimised shielding implementation : the methodology developed helps NPP in choosing the best ALARA radiation protection options. Global dose decrease for a similar outage Global outage dose 664,82 613, (VP)2007(VP) Year Dose (HmSv) TR1 Shielding contractor dose decrease Shielding contractor dose 17,63 7, (VP)2007(VP) Year Dose (HmSv) TR1

2008 ISOE conference H. BERTIN EDF-UTO 14 This progress, based on TRICASTIN example, is due to: More biological protections Mechanical stress calculations Contributing sources identification Justification of the lead mattresses’ thickness from 6 mm to 12 mm Optimal scenario definition

2008 ISOE conference H. BERTIN EDF-UTO 15 New biological protection Permanent shielding support

2008 ISOE conference H. BERTIN EDF-UTO 16 Conclusion These elements leads to encouraging collective integrated dose decrease compared to the historical and empirical approaches that were previously implemented on-site. A prototype tool, that will help NPPs to analyse the optimal shielding protection implementation scenario, will be tested in 2 years on a real outage in Tricastin in 2010.