Analysis of in-core dynamics in pressurized water reactors with application to parameter monitoring

Conference · Thu Jan 01 04:00:00 EST 1987

OSTI ID:6238027

Upadhyaya, B R; Sweeney, F J; Shieh, D J; Glockler, O

The behavior of the phase relationship between neutron flux and core-exit temperature fluctuations in a pressurized water reactor (PWR) is studied as a function of the moderator temperature coefficient of reactivity (..cap alpha../sub c/). PWR operational data indicate that the neutron noise and core-exit temperature noise cross power spectrum phase is linear in a certain frequency range, and approaches -180 deg at low frequencies. Extensive modeling studies applied to the LOFT reactor show that this low frequency phase behavior changes when ..cap alpha../sub c/ is positive, approaching zero deg at low frequencies. The analysis further showed that in the LOFT reactor, coolant flow rate fluctuation is the primary driving source causing neutron noise and core-exit temperature fluctuations. This conclusion was also confirmed by independent studies. The neutron noise-coolant temperature phase behavior may be used as a single method of monitoring the moderator temperature coefficient of reactivity during different stages of a PWR fuel cycle.

• Research Organization: Oak Ridge National Lab., TN (USA); Institute of Nuclear Energy Research, Lung-Tan (Taiwan); Tennessee Univ., Knoxville (USA)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6238027
• Report Number(s): CONF-871013-1; ON: DE87013181
• 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
FUEL CYCLE
MEASURING INSTRUMENTS
MONITORING
NEUTRON FLUX
PHYSICS
PWR TYPE REACTORS
RADIATION FLUX
REACTIVITY
REACTIVITY COEFFICIENTS
REACTOR COMPONENTS
REACTOR CORES
REACTOR NOISE
REACTOR PHYSICS
REACTORS
TEMPERATURE COEFFICIENT
TEMPERATURE GRADIENTS
WATER COOLED REACTORS
WATER MODERATED REACTORS