WNU Summer Institute 2010

Evolution of Reactor Designs

World Wide Reactor Typesreactor type operational number Elect. Net output MW

PWR 266 245,397

BWR 92 83,690

CANDU/D2O-PWR 45 22,635

GGR/AGR 18 8,949

RBMK 15 10,219

FBR 1 560

Total 437 371,450

Nuclear Power Plants, world-wide, reactor types, March 21, 2010

Generation lll Nuclear Reactors

Generation lll Nuclear Reactors Nuclear reactors are constructed and operated in order to

satisfy a public need for the safe, economic and reliable supply of electricity.

The economic models in which nuclear plants are required to operate have become more challenging

Since the time of the second generation of reactors public expectations in respect of safety and security standards have become more demanding.

Developments in nuclear power plant technology and innovations in design offer new possibilities for addressing those challenges

Generation lll Nuclear Reactors

Generation lll Nuclear ReactorsDesign Innovations are intended to result in :-

Improved safety performance

Reduction in construction costs

Shorter construction times

Longer operating lifetimes

Improved availability

Improved fuel utilisation

Higher thermal efficiency

Collectively these initiatives are expected to address the imperatives for new build

.

PWR Model

PWR Reactor

PWR Fuel Assembly

PWR Post Trip Cooling

EPR Reactor

EPR Reactors The EPR is more evolutionary than revolutionary in its design.

It seeks to incorporate proven features from the successful Arriva N4 and

the Siemens Konvoi reactors.

Key features include:-

Four safety trains each of which is capable of providing post trip cooling

Enhanced segregation of the safety trains

A double skinned reinforced concrete containment capable of withstanding

aircraft impact

A core catcher

An enlarged core offering greater output and fuel efficiency

A reactor vessel made of materials chosen for their anti aging properties

A sixty year design life with the potential for life extension beyond that.

AP 1000

AP 1000 Principle Design Features The AP1000 seeks to build and improve upon the established technology of

major components used in current Westinghouse-designed plants with

proven, reliable operating experience over the past 50 years.

Examples of proven technology used in the design, include pumps, valves,

digital I&C systems, steam generators and pressurisers.

The AP 1000 uses only two steam generators to produce an output of 1000

MW electrical thus reducing costs.

The RCPs are fully integrated into the Steam Generator bottom shells, two

per SG further simplifying the primary circuit geometry.

Factory fabrication of key components is built into the design philosophy to

enable them to be manufactured in controlled environments away from the

construction site. This reduces cost, enhances control, quality and

production performance.

Westinghouse AP 1000

AP 1000 Passive Cooling System

Westinghouse AP 1000

AP 1000 Design FeaturesThe design philosophy results in:-

50% fewer safety-related valves

80% less safety-related piping

85% less control cable

35% fewer pumps

45% less seismic building volume

It is claimed that these innovations save money and time with an accelerated construction time period of approximately 36 months, from the pouring of first concrete to the loading of fuel.

Boiling Water Reactor

1. Vessel Flange and Closure

Head

2. Vent and Head Spray

3. Steam Outlet Flow Restrictor

4. RPV Stabilizer

5. Feedwater Nozzle

6. Forged Shell Rings

7. Vessel Support Skirt

8. Vessel Bottom Head

9. RIP Penetrations

10. Thermal Insulation

11. Core Shroud

12. Core Plate

13. Top Guide

14. Fuel Supports

15. Control Rod Drive Housings

16. Control Rod Guide Tubes

17. In Core Housing

18. In-Core Instrument Guide

Tubes

and Stabilizers

19. Feedwater Sparger

20. High Pressure Core Flooder

(HPCF) Sparger

21. HPCF Coupling

22. Low Pressure Flooder

(LPFL)

23. Shutdown Cooling Outlet

24. Steam Separators

25. Steam Dryer

26. Reactor Internal Pumps

(RIP)

27. RIP Motor Casing

28. Core and RIP Differential

Pressure Line

29. Fine Motion Control Rod

Drives

30. Fuel Assemblies

31. Control Rods

32. Local Power Range Monitor

Advanced

ADVANCED BOILING WATER

REACTOR

UK Nuclear Reactors

Magnox Reactors

Magnox Reactors

Magnox Reactors

Magnox Fuel Rod

Generation lll Reactors

AP 1000 Principle Design Features

Simplification was a major design objective for the AP1000. The use of passive safety systems reduces the need for engineered safeguards and the plant and equipment associated with them, together with the seismically qualified buildings to house them. The result is a plant that is easier and less expensive to build, operate and maintain.

Factory fabrication of key components is built into the design philosophy to enable them to be manufactured in controlled environments away from the construction site. This enhances control, quality and production performance.

Reactor Circulation Pumps and Motors are fully enclosed into the primary circuit. Two pumps per steam generator. There are no external glands or loop pipes to couple them into the primary circuit.

The pumps have flywheels to prolong run down times in the event of a loss of power to aid the transition from forced cooling to shutdown cooling