Effect of photoneutrons on transients of beryllium reflected reactors
An analytical model is developed to account for the photoneutron sources present in a beryllium reflector. The time-dependent, two-dimensional and three energy-group diffusion equations are written with an additional photoneutron source term. Then an approximate flux composed of two spatial shapes chosen beforehand, each having an unknown time coefficient, is inserted into time-dependent multigroup equations and the weighted residual criterion is applied. This yielded multimode kinetics equations with generalized definitions for conventional matrix parameters: generation time, reactivity, delayed neutron and delayed photoneutron fraction matrices. Two transients are analyzed for the University of Missouri Research Reactor: simulation of rod drop experiment and rod withdrawal accident. For the first transient the effect of photoneutrons is found to be negligible. For the second case the photoneutron effect, though small, tends to slow down the transient. This study suggests that a space-dependent analysis is necessary to analyze both the transients.
- Research Organization:
- Missouri Univ., Rolla (USA)
- OSTI ID:
- 7353650
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
220600* -- Nuclear Reactor Technology-- Research
Test & Experimental Reactors
ALKALINE EARTH METALS
BARYONS
BERYLLIUM
ELEMENTARY PARTICLES
ELEMENTS
ENRICHED URANIUM REACTORS
EQUATIONS
FERMIONS
HADRONS
KINETICS
METALS
NEUTRON REFLECTORS
NEUTRONS
NUCLEONS
PHOTONEUTRONS
PHOTONUCLEONS
POOL TYPE REACTORS
REACTION KINETICS
REACTOR KINETICS EQUATIONS
REACTORS
RESEARCH AND TEST REACTORS
RESEARCH REACTORS
THERMAL REACTORS
TRAINING REACTORS
TRANSIENTS
UMRR REACTOR
WATER COOLED REACTORS
WATER MODERATED REACTORS