U.S. EPR Design Overview

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U.S. EPR Design Overview

• Mark Smith
• Principal Engineer
• New Plants Deployment
• AREVA NP, Inc.

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Design Heritage

• EPR is a global product based on U.S. technology
  and experience that have been advanced to the
  next level.

A mature design based on familiar technology
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European Utility Participants
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EPR Development Objectives

• Evolutionary design based on existing PWR
  construction experience, RD, operating
  experience and lessons learned.

• Improved economics
• Reduce generation cost by at least 10
• Simplify operations and maintenance
• Safer
• Reduce occupational exposure and LLW
• Increase design margins
• Reduce core damage frequency (CDF)
• Accommodate severe accidents and external hazards
  with no long-term local population effect

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General Plant Layout
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Major Design Features

• Nuclear Island
• Proven Four-Loop RCS Design
• Four-Train Safety Systems
• Double Containment
• In-Containment Borated Water Storage
• Severe Accident Mitigation
• Separate Safety Buildings
• Advanced Cockpit Control Room

• Electrical
• Shed Power to House Load
• Four Emergency D/Gs
• Two Smaller, Diverse SBO D/Gs
• Site Characteristics
• Airplane Crash Protection (military and
  commercial)
• Explosion Pressure Wave

Reflects full benefit of operating experience and
21st century requirements.
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• Conventional 4-loop PWR design, proven by decades
  of design, licensing operating experience.
• NSSS component volumes increased compared to
  existing PWRs, increasing operator grace period
  for many transients and accidents

A solid foundation of operating experience.
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EPR Plant Parameter Comparison

Increased Margin, Safety and Performance
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Core Characteristics

• Increased Uranium utilization (8 reduction in
  uranium consumption)
• Designed for use of MOX fuel
• Designed for 12 to 24 month fuel cycle
• Up to 5 enrichment
• gt 60 GWd/t burn-up

Designed for increased flexibility performance
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Fuel Design Proven By Operation

• 17x17
• Typical Pitch-to-Diameter Ratio
• M5 Cladding
• Heated Length Similar to N4
• M5 HTP Mixing Vane Grids
• Anti-Debris Lower End Fitting
• Significant Design Margins
• MOX Compatible

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EPR Core Design Parameters
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Improved Design Margin
Increased power with improved margins.
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The Four Train Concept
Each safety train is independent and located
within a physically separate building.
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The Four Train Concept (contd)

• Preventive maintenance during power operation
• Shorter outage time
• Simplified technical specifications
• Higher Availability

4 Independent Safety Trains Arranged into 4
divisions

• Efficient hazard protection
• Reduced piping and components
• Optimized plant layout
• Lower Unit Cost

• Smaller components
• No header between trains
• Fewer valves per train
• Easier Maintainability

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Four-Train Concept

• On-line maintenance without entering action
  statements
• Radial arrangement simplifies layout and reduces
  piping
• Active cross-connects eliminated
• Simplifies systems
• Minimizes components
• Reduces operator burden in case of accident
• Reduced component sizes
• Separate safeguards buildings
• Physical separation
• Improved hazards mitigation -- fire, flood,
  external events

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Section View
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Operator-Friendly Man-Machine Interface
N4 Control Room
EPR Control Room
Capitalizing on nuclear digital IC operating
experience and feedback.
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POP Displays
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Equipment Improvements
No penetrations in RV lower head.

• Martinsitic CRDM housing. Forced convection
  cooling of coils not req'd.

RCP stand-still seal eliminates leakage during
SBO.
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Equipment Improvements
Two normal pzr spray (ea. from different CL) plus
one aux spray

• Extensive use of forgings with integral nozzles.
• Materials resistant to corrosion and cracking
• 304L SS hot/cold legs
• 304L SS surge line
• 316L RV internals
• 308/309 SS cladding
• Alloy 690 SG tubes
• 410 SS TSPs
• 405 SS AVBs

• Conventional core baffle replaced by heavy
  reflector.
• Eliminates bolting
• Improves neutron economy
• Reduces vessel fluence

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Operating Experience Incorporated

• Self-checking digital IC
• No safety-related containment fan coolers
• Containment spray is non-safety (for severe
  accident)
• Extensive use of materials resistant to FAC
• No turbine-driven MFW or AFW pumps (all electric)
• Main steam relief safety valves reduced from 8
  - 10 to 3 per loop

Reduced Maintenance Surveillance Testing
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Operating Experience Incorporated

• Elimination of Single-Point Vulnerabilities
• Three 50 Condensate Pumps
• Bypass of components for maintenance with no
  derate
• Duplicates of key components (e.g., demins, Hx's)
  to allow isolation for maintenance
• Rapid runback prevents Rx trip on loss of MFW or
  RC pump
• Layout to Facilitate Maintenance
• Room for access designed in
• Equipment on floors or permanent platforms
  provided
• Most components can be removed and replaced via
  pre-designed pathways and equipment hatches using
  installed lifting devices
• ALARA
• Minimize Cobalt in plant components
• Vessels and Hx's designed to minimize deposits
• Use of "Hot" and "Cold" zones

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Use of Hot Cold Zones
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U.S. Industry-Average Dose Per Reactor
1973-2004, (Person-rem)
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Operating Experience Incorporated

• Cooldown to 140F in lt 24 hrs
• Early entry to containment for equipment PM
  testing
• RVCH removal ready to move fuel in 98 hrs
• Refueling machine capacity 6 assemblies/hr
  (minimum)
• Fuel sipping while assembly shuffled
• Full core offload in 41 hrs
• Rapid plant heat-up of 72 F/hr on 4 RCPs (start
  of RCS fill to start of Mode 2 in 24 hrs)

Designed For Outage Optimization
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Containment Concepts

• Two-Room Concept
• Access during operation for equipment repairs or
  outage prep
• Storage space for tools or scaffolding allows
  setup before equipment hatch is open
• Ample lay-down space
• Equipment maintenance
• Planned storage (RVCH, RVIs, Instrument Lances,
  etc)
• Permanent maintenance platforms (e.g., SG
  manways, Pzr Valves)
• Permanent cavity seal plate
• Easy access to RVCH via water-tight doors

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Operating Experience Incorporated Designed For
Outage Optimization
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Conclusions

• EPR is evolutionary
• Most features are typical of operating PWRs
• Features included to
• Improve Safety
• Increase redundancy separation
• Reduce core damage frequency
• Reduce large early release frequency
• Mitigate severe accident scenarios
• Protect critical systems from external events
• Aircraft Hazard
• External Explosion
• Flood
• Improve human factors
• Lower OM Costs
• Simplified Systems
• On-Line Maintenance
• Use of latest, proven technology
• Economy of Scale