2. > NRC Regulatory Information Conference March 12, 2009 AREVA NP Inc. 2 AREVA Perspectives on the Containment Sump Design and Downstream Effects for U.S. EPR TM Design Fariba Gartland Project Manager AREVA NP Inc. NRC Regulatory Information Conference Rockville, MD March 12, 2009 EPR is a trademark of the AREVA Group

3. > NRC Regulatory Information Conference March 12, 2009 AREVA NP Inc. 3 >Innovative and comprehensive solution to the concerns of GSI-191 >Defense-in-depth strategy >Supporting test program >Inspections, tests, analyses and acceptance criteria (ITAAC) Introduction Olkiluoto-3 EPR Project, Finland January 2009

4. > NRC Regulatory Information Conference March 12, 2009 AREVA NP Inc. 4 US EPR TM ECCS Sump Blockage Mitigation Design Features Design Detail

5. > NRC Regulatory Information Conference March 12, 2009 AREVA NP Inc. 5 >Insulation material >Four protective weir / trash rack structures >Four retaining baskets in the IRWST >Large area, low flow velocity region within the IRWST >Four large surface area three-dimensional flat screen sump strainers in the IRWST Defense-in-Depth Strategy

6. > NRC Regulatory Information Conference March 12, 2009 AREVA NP Inc. 6 >Also contributing to the overall effectiveness of the system:  Retaining basket overlaps trash rack portal area  Overflow from retaining baskets to IRWST  Retaining basket screen mesh size is identical to the strainer screen mesh size  Inverted side screens on the sump suction strainers Additional Features Strainer Retaining Basket

7. > NRC Regulatory Information Conference March 12, 2009 AREVA NP Inc. 7 IRWST Cut-away View ECCS Strainer ECCS Strainer Retaining Basket Trash Rack Retaining Basket

8. > NRC Regulatory Information Conference March 12, 2009 AREVA NP Inc. 8 >ECCS Strainer Testing  Test facility Scaling: 1:1 vertical and 1:20 for all other parameters (horizontal, flow rate, screen size, debris amount)  Test results Three-tiered design very effective Retaining baskets retained 95% of total debris Testing ECCS strainer testing demonstrates effectiveness of three-tiered design

9. > NRC Regulatory Information Conference March 12, 2009 AREVA NP Inc. 9 >Potential blockage minimized by:  The retaining basket and sump strainer screens are the same mesh size, 0.08 x 0.08 inches  High debris retention in the baskets (95%) >Fuel:  U.S. EPR design uses very little fibrous insulation  Evaluations of fuel under expected debris load will be completed according to current industry standards >Components:  Downstream components (e.g., ECCS pumps) will be specified to accommodate expected debris load Downstream Effects Debris types and design features minimize potential for blockage

10. > NRC Regulatory Information Conference March 12, 2009 AREVA NP Inc. 10 >Pre-operational inspections on key design features affecting sump screen performance:  Trash racks over floor openings  Weir at floor and wall openings  Retaining baskets below floor openings  IRWST suction strainer ITAAC ITAAC provide confirmation that installation of key components meets the design bases

11. > NRC Regulatory Information Conference March 12, 2009 AREVA NP Inc. 11 >The potential debris source term is minimized. >The U.S. EPR sump design has advanced and redundant features with respect to post-accident debris accumulation and ECCS recirculation sump strainer blockage. Conclusion GSI-191 concerns addressed through defense-in-depth strategy