Analysis and monitoring of in-core dynamics in pressurized water reactors

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1985

OSTI ID:5148530

Shieh, D J

The applicability of the core-exit coolant temperature and the neutron power noise signals for core coolant flow rate estimation and for monitoring the sign of the moderator temperature coefficient of reactivity in PWRs are studied. Three kinds of models are developed to investigate the mechanisms involved in the noise signals: the phenomenological model, the distributed parameter model, and the multi-nodal model. The Loss-of-Fluid Test (LOFT) reactor is selected as the baseline reactor for this study. The phase relationship between the core-exit coolant temperature and the neutron power signals is found to have a linear phase-frequency behavior in a certain frequency region (about 0.1-2 Hz) with lower and upper bounds which are functions of the system dynamics parameters. The slope of this phase is inversely proportional to the core flow rate. The phase at zero frequency extrapolated from this linear phase-frequency region is -180/sup 0/ for a negative moderator temperature coefficient of reactivity and 0/sup 0/ for a postivie moderator temperature coefficient. The feasibility of using a stochastic estimator to estimate the flow rate using the core-exit coolant temperature and the neutron noise signals is also studied.

• Research Organization: Tennessee Univ., Knoxville (USA)
• OSTI ID: 5148530
• 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
DYNAMICS
LOFT REACTOR
MECHANICS
MONITORING
PWR TYPE REACTORS
REACTIVITY COEFFICIENTS
REACTOR COMPONENTS
REACTOR CORES
REACTOR NOISE
REACTORS
RESEARCH AND TEST REACTORS
TANK TYPE REACTORS
TEST REACTORS
WATER COOLED REACTORS
WATER MODERATED REACTORS