BMB-LWR core moderator coefficient and its WDR reactivity worth

Conference · Fri Jan 01 04:00:00 EST 1988 · Trans. Am. Nucl. Soc.; (United States)

OSTI ID:5958606

Abu-Zaied, G

Control of the excess reactivity for burnup in pressurized water reactors (PWRs) is accomplished using soluble poison and/or burnable poison. The boron concentration must be limited during operating conditions to ensure that the moderator temperature coefficient (MTC) is negative. Sufficient burnable poison is installed at beginning of cycle (BOC) to give the desired cycle lifetime without exceeding the boron concentration limit. If the cyclelength is increased, the burnable poison loading has to be increased, which (for heterogeneous burnable poison, such as most boron-based schemes) displaces fuel rods and increases intraassembly power peaking. Note that even at end-of-cycle (EOC) conditions some residual poison remains, resulting in a net decrease in cycle lifetime. Accordingly, the next step is to search for concept variations that are more practical from a thermal-hydraulic view-point even at some sacrifice in fuel savings. The approach selected for subsequent study involved fuel reconstruction combined with the use if water displacement rods (WDRs) in a design concept designated as the breeder/moderator controlled/burner light water reactor (BMB-LWR). The reference reactor to which the new design was compared is a standard Westinghouse PWR, operating on an extended burnup fuel cycle, since the BMB-LWR core was also designed to have a longer cycle than has been past practice.

• OSTI ID: 5958606
• Report Number(s): CONF-881011-
• Conference Information: Journal Name: Trans. Am. Nucl. Soc.; (United States) Journal Volume: 57
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
210200* -- Power Reactors
Nonbreeding
Light-Water Moderated
Nonboiling Water Cooled
ACTINIDES
BORON
BREEDER REACTORS
COMPARATIVE EVALUATIONS
CONTROL ELEMENTS
ELEMENTS
ENERGY TRANSFER
ENRICHED URANIUM
FLUID MECHANICS
FUEL ELEMENTS
FUEL PINS
HEAT TRANSFER
HYDRAULICS
ISOTOPE ENRICHED MATERIALS
LWBR TYPE REACTORS
MATERIALS
MECHANICS
METALS
MODERATOR-FUEL RATIO
MODERATORS
MULTIPLICATION FACTORS
NUCLEAR POISONS
PWR TYPE REACTORS
REACTIVITY
REACTOR COMPONENTS
REACTOR CORES
REACTOR MATERIALS
REACTOR SHUTDOWN
REACTORS
SEMIMETALS
SERVICE LIFE
SHUTDOWNS
SLIGHTLY ENRICHED URANIUM
SOLUBLE POISONS
TEMPERATURE DEPENDENCE
THERMAL REACTORS
URANIUM
WATER COOLED REACTORS
WATER MODERATED REACTORS