Influence of the upper cavity on neutron physics of the pebble-bed reactor

Technical Report · Thu Mar 01 04:00:00 EST 1973

OSTI ID:4935760

Maly, V

In the pebble-bed reactor there is a cavity between the upper reflector and core. In the case of the OTTO (Once Through Then Out) reactor with its strongly asymmetric flux and power profile, detailed knowledge of flux and power distribution in its neighborhood is of particular interest. The cavity effect has been investigated for the process-heat reactor PR-500 by applying the 2D SN transport code. A comparison of the results achieved by the diffusion and transport approximation has been performed. The influence of the real structure in the upper reactor regions on the neutron distributions has been discussed in detail. There is a strong radial flattening of neutron flux profile and of power density in the vicinity of the cavity. The cavity influence on the effectivity of control rods has been investigated. It appears that the normal power-load scheme can be controlled merely by the control rods situated above the pebble-bed. (auth)

• Sponsoring Organization: Sponsor not identified
• NSA Number: NSA-29-011796
• OSTI ID: 4935760
• Report Number(s): JUL--932-RG
• Country of Publication: Germany
• Language: German

Related Subjects

CAVITIES
N77300* --Reactors--Power Reactors
Non-breeding
Graphite Moderated
NEUTRON FLUX
NEUTRON TRANSPORT
PEBBLE BED REACTORS
POWER DENSITY
PROCESS HEAT REACTORS
REACTOR CORES
REACTOR KINETICS
VOIDS