ALARA STUDIES FOR EDF NUCLEAR POWER PLANTS Presentation

ALARA STUDIES FOR EDF NUCLEAR POWER PLANTS

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 2 2008 ISOE conference H. BERTIN EDF-UTO

1. A brief presentation of EDF Group and UTO

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 4 2008 ISOE conference H. BERTIN EDF-UTO Installed capacity

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

2. From PANTHER-RP simulation to practical recommandations

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

An UTO recommandation example shielding definition • BOUCLE 1 – Local R 412 – RCP 120 VP Radiological – protection option • 12 mm lead shield in front of hot branch • Lead matress aound RCP 120 valve RCP 120 VP 12 mm lead shield Lead matress - 8 2008 ISOE conference H. BERTIN EDF-UTO 5

3. An implementation example

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

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

4. Gains

Gains : the integrated dose In 2006 : radiological gains around 25 H. m. Sv 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. Shielding contractor dose decrease Global dose decrease for a similar outage Global outage dose Shielding contractor dose 660 664, 82 20 640 TR 1 620 613, 617 600 580 2005(VP) 2007(VP) Year Dose (Hm. Sv) 680 17, 63 15 10 TR 1 7, 05 5 0 2005(VP) 2007(VP) Year 13 2008 ISOE conference H. BERTIN EDF-UTO

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

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

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. 16 2008 ISOE conference H. BERTIN EDF-UTO