GENERATION III AND III+ GENERATION III AND III+

NUCLEAR POWER PLANT DESIGNSNUCLEAR POWER PLANT DESIGNS

ACR-1000ACR-1000

(Advanced CANDU(Advanced CANDU Reactor Reactor))

Dr. Şule Ergün

Hacettepe University

Department of Nuclear Engineering

March 2008, Istanbul

Outline

• CANDU Concept

• CANDU Development

• ACR-1000– Technical Description

• Conclusion

CANDU Concept

Pressurized Heavy Water Reactor

(CANadian Deterium Uranium)

•CANDU6

•ACR-700

•ACR-1000

CANDU Development

CANDU Development

• The CANDU Design:– Modular horizontal fuel channels– Simple fuel bundle design– Separated coolant from moderator– Cool, low pressure heavy water moderator– On-power fuelling– Passive shutdown systems

ACR-1000

• Low enriched fuel

• Light water coolant

• Higher steam pressure

• Smaller reactor core

• High capacity factor

• Over 60 year life

• Larger thermal margins

ACR-1000

Evolution in Core Size

CANFLEX Fuel Bundle

ACR-1000

• Safety Enhancements– Enhanced passive safety– Factor of ten improvement in severe core

damage frequency

• Improved Construction– Shorter construction schedule– Reduce cost by 25% or more

ACR-1000

• ECC System:– Initial injection from

pressurized ECI tanks located inside Reactor Building (RB)

– Long Term Cooling (LTC) System provides pumped recovery

– LTC System also provides maintenance cooling after normal shutdown

ACR-1000

Frequency for internal events:

~ 3 x 10-7/ reactor year

ACR-1000• Severe accident mitigation:

– Passive Core Make-Up Tanks keep HTS full to assure thermosyphoning capability

– Reserve Water System (RWS) supply by gravity to SGs provides inventory for long-term thermosyphoning

– Passive make-up to HTS from ECI and RWS delay accident progression

– Passive make-up to moderator and calandria vault from RWS delay accident progression

– Passive spray system supplied from RWS delays containment failure

Conclusion• The ACR-1000 innovations include:

– A compact core design which reduces heavy water inventory and results in lower costs and reduced emissions

– Use of light water as reactor coolant, resulting in reduction of systems for heavy water coolant cleanup and recovery and simplification of containment atmosphere cleanup systems

– Use of low enriched uranium fuel, contained in advanced CANFLEX ACR fuel bundles

Conclusion– Efficient means for burning other fuel types

such as mixed oxides (MOX) and thorium fuels– Increased fuel safety margins– Improved plant thermal efficiency through use

of higher pressures and higher temperatures in the coolant and steam supply systems

– Enhanced accident resistance and core damage prevention features

– Enhanced operability and maintainability