IRIS DEVELOPMENT

1. IRIS DEVELOPMENT Mario D. Carelli Westinghouse Electric Co. LLC LAS/ANS Symposium Rio de Janeiro June 14, 2005

2. IRIS MOST SIGNIFICANT DISCRIMINATORS • Integral design configuration • Simplicity • Safety approach through safety-by-design™ • International consortium

3. AN ADVANCED, MODULAR, MEDIUM-POWER LWR 335 MWe

4. INTERNATIONAL REACTOR INNOVATIVE AND SECURE- IRIS PROJECT - 21 organizations 10 countries Industry AE Vendors Laboratories Universities

5. IRIS TEAM

6. INTERNATIONAL CONSORTIUM • Westinghouse leads project, but is “primus inter pares” (first among equals). All members are stakeholders. • IRIS members contribute to project at their own risk and will share in rewards, commensurate to their contribution. • Regardless of size of contribution, all members have access to totality of information generated and participate to all deliberations. • Universities and laboratories are integral parts of design team.

7. BENEFITS • The following are examples of the benefits available to members: • A share in the profits resulting from future IRIS sales • “For Profit” contracts, including rights (not exclusive) to manufacture specific components • “For Profit” contracts, relating to specific R&D work • A Royalty fee for the use of any Patents specifically developed for IRIS • A Royalty fee for the use of any prior information specifically used and directly applicable to IRIS. All Public Domain information is inadmissible. • Placements, Scholarships, Sponsorships, Collaborative projects and use of the brand Name

8. IRIS SCHEDULAR OBJECTIVES • Program started October 1999 • Assess key technical & economic feasibility End 2000 (completed) • Perform conceptual design, preliminary cost End 2001 estimate (completed) • Initiate licensing pre-application (completed) Fall 2002 • Develop licensing plan (completed) Fall 2002 • Outline path to commercialization(completed)Early 2003 • Perform preliminary design 2002-2005 • Complete licensing pre-application Spring 2006 • Obtain final design approval 2010 • First module deployment 2012-2015

9. IRIS INTEGRAL SYSTEM Integral configuration (integral primary loop) All major primary loop components are inside a single pressure vessel (eliminates loop piping and external components)

10. INTEGRAL COMPONENTS OFFER BETTER DESIGN AND PERFORMANCE Steam generators Tubes in compression. Tensile stress corrosion cracking eliminated (responsible for over 70% reported failures) Primary coolant pumps No seal leaks. No shaft breaks. No maintenance. Internal CRDMs No head penetrations, no seal failures, no head replacements, no $800M cost a la Davis Besse Pressurizer Much larger volume/power ratio gives much better pressure transients control. No sprays. 1.7 meter thick Vessel fast flux 105 times lower. Cold vessel. Almost no downcomer annulus outside dose. No embrittlement, no surveillance. “Eternal” vessel. Simpler decommissioning. Fuel assembly Almost the same as standard W PWR, but can have extended cycle up to 48 months

11. IRIS APPROACH Simplicity Economy Safety • Proven light water technology • Significant engineering, not technology changes • An international group is the best avenue to attain above, since: • New ideas from most diverse constituents, cultures • Eliminated in house corporate mindset and • Must pass technical and commercial feasibility review by the organization who has designed and deployed PWRs worldwide for over 50 years

12. IRIS PLANT LAYOUT • Developed in response to US utilities as part of the Early Site Permit Program • Basic configurations: Single module (335 MWe) Twin units (670 MWe) Offered individually or as “pack” • For US utilities, requiring at least 1000 MWe, IRIS offered three single modules or two twin units

13. COSTS OUTFLOW

14. IRIS “SAFETY-BY-DESIGN”™ APPROACH Exploit to the fullest what is offered by IRIS design characteristics (chiefly integral configuration) to: • Physically eliminate possibility for some accidents to occur • Decrease probability of occurrence of most remaining accident scenarios • Lessen consequences if an accident occurs

15. IRIS THREE-TIER SAFETY • SAFETY-BY-DESIGN™ Aims at eliminating by design possibility for accidents to occur Eliminates systems/components that were needed to deal with those accidents • PASSIVE SAFETY SYSTEMS Protect against still remaining accidents and mitigate their consequences Fewer and simpler than in passive LWRs • ACTIVE SAFETY SYSTEMS No active safety systems are required But, active non-safety systems contribute to reducing the probability of CDF (core damage frequency) IRIS APPROACH IS ECONOMICAL: IMPROVES SAFETY WHILE SIMPLIFYING DESIGN

16. IMPLEMENTATION OF SAFETY-BY-DESIGN™ { } – Only accident where effect is potentially negative

17. TYPICAL PWR CLASS IV ACCIDENTS AND THEIR RESOLUTION IN IRIS DESIGN

18. PRELIMINARY PRA LEVEL 1

19. EXTREMELY LOW INTERNAL EVENTS CDF IS A DIRECT CONSEQUENCE OF IRIS SAFETY-BY-DESIGN™ PHILOSOPHY • IRIS eliminates most of the accidents which are very improbable • There is no need for corrective systems • There are fewer things which can go wrong • Reliability increases • Improved response to those accidents which are less improbable

20. IRIS SAFETY-BY-DESIGN™: THE BOTTOM LINE IMPLICATIONS: Both advanced LWRs and IRIS are extremely safe plants

21. A DIFFERENT APPROACH TO SAFETY • What does it really mean 10-6 versus 10-8 CDF? • IRIS is not focused on just being “safer” • Make the remote probability that a serious accident might happen even more remote • IRIS is focused on immediate, tangible advantages • With probability=1, provide: • Reduced cost • Improved licensing regulations

22. ECONOMICS • Improved safety is not achieved by adding more and/or better safety systems • Through safety-by-design™ improved safety is achieved by eliminating safety systems and/or simplifying remaining ones • Result: enhanced safety and reduced cost

23. IRIS Safety-by-Design™: The 5 Most Severe Accident Precursors since 1979 as Ranked by NRC Cannot Occur or are Intrinsically Mitigated in IRIS

24. LICENSING REGULATIONS • The combined effect of safety-by-design™ and PRA-guided design has given failure and release probabilities far lower values than those considered acceptable when current licensing regulations were promulgated • Possibility to license IRIS with revised emergency planning such to significantly reduce emergency planning zone and possibly collapse it into the site boundary

25. SOME ADVANTAGES OF NO EMERGENCY RESPONSE Economic • No need of special measures and infrastructure (e.g., new roads) for rapid evacuation • Can locate plant near user (reduced transmission lines, and allowance of co-generation, e.g., desalination and district heating) • No impediment to further development and settlement in area around the plant • No need for special training of personnel and for periodic drills • Reduces licensing uncertainties Social • IRIS is treated no differently than any other power producing industrial facility • Removes stigma from nuclear power • No more “NIMBY” (not in my back yard) • Public acceptance increased

26. IRIS APPROACH TENETS • Combine deterministic and probabilistic assessment • Revise barriers in Defense in Depth, without compromising final outcome • Consider all realistic accidents • Do not postulate a priori accidents • Evaluate consequences and their probability of occurring

27. CURRENT REACTORS DEFENSE IN DEPTH • Limit initiating events • Active Protective systems • Materials barriers Fuel Cladding Vessel and piping Containment • Accident management On site emergency response Off site emergency response (10 mile EPZ)

28. IRIS DEFENSE IN DEPTH • Technology Neutral, Safety-by-design™ barrier Accidents eliminated Consequences downgraded Probabilities reduced by design configuration • Few passive protective systems; no active protective systems • Material barriers Fuel Cladding Large coolant inventory Vessel Containment • Accident Management Onsite emergency response EPZ may be reduced to the plant boundary

29. IRIS EMERGENCY PLANNING STATUS • IRIS is in forefront of effort to revise emergency licensing regulations • Position and proposed procedure presented to NRC at Workshop on March 14-16, 2005, and well received by NRC. Will cooperate with NEI and EPRI in further studies. • Position and proposed procedures presented to IAEA at technical meeting on November 15-19, 2004. IAEA is currently coordinating within a CRP on “small and medium reactor with infrequent on site refueling” five studies on reducing/eliminating off-site emergency response planning by the following IRIS organizations: • Westinghouse: Regulatory procedures • Polytechnic of Milan, Italy: Methodology • University of Zagreb, Croatia: Transient analyses • Lithuanian Energy Institute: Impact of external events and economics aspects especially with respect to district heating • Eletronuclear, Brazil: Economics and utility perspective • Also presented at OECD Workshop on April 26, 2005. Further collaborations possible.

30. CONCLUSIONS • Greatly enhanced safety, built on simplicity and delivering improved economics • Simple design, modular, very competitive • On track for design certification ~ 2010; deployment by ~ 2015 • Strong contributions from Latin American partners • Very well suited to address Latin America electricity and potable water needs