Experimental study of neutron streaming through steel-walled annular ducts in reactor shields

Journal Article · Tue Mar 01 04:00:00 EST 1983 · Nucl. Sci. Eng.; (United States)

OSTI ID:5384313

Toshimas, M; Nobuo, S

For the purpose of providing experimental data to assess neutron streaming calculations, neutron flux measurements were performed along the axes of the steel-walled annular ducts set up in a water shield of the pool-type reactor JRR-4. An annular duct simulated the air gap around the main coolant pipe. Another duct simulated the streaming path around the primary circulating pump of the integrated-type marine reactor. A 90-deg bend annular duct was also studied. In a set of measurements, the distance Z between the core center and the duct axis and the annular gap width delta were taken as parameters, that is, Z = 0, 80, and 160 cm and delta = 2.2, 4.7, and 10.1 cm. The reaction rates and the fluxes measured by the activation method are given in terms of absolute magnitude within an accuracy of + or - 30%. An empirical formula is derived based on those measured data, which describes the axial distribution of the neutron flux in the steel-walled annular duct in reactor shields. It is expressed by a simple function of the axial distance in units of the square root of the line-of-sight area, S /SUB l/ . The accuracy of the formula is examined by taking into account the duct location with respect to the reactor core, the neutron energy, the steel wall thickness, and the media outside of the steel wall. The accuracy of the formula is, in general, <30% in the axial distance between 3..sqrt..S /SUB l/ and 30..sqrt..S /SUB l/ .

• Research Organization: Ship Research Institute, Tokai Branch Tokai-mura, Ibaraki-ken
• OSTI ID: 5384313
• Journal Information: Nucl. Sci. Eng.; (United States), Journal Name: Nucl. Sci. Eng.; (United States) Vol. 83:3; ISSN NSENA
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
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654002 -- Radiation &amp; Shielding Physics-- Shielding Calculations &amp; Experiments-- (-1987)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALLOYS
ANNULAR SPACE
CONFIGURATION
DUCTS
ENRICHED URANIUM REACTORS
IRON ALLOYS
IRON BASE ALLOYS
JRR-4 REACTOR
NEUTRON FLUX
POOL TYPE REACTORS
RADIATION FLUX
RADIATION STREAMING
REACTORS
RESEARCH AND TEST REACTORS
RESEARCH REACTORS
SHIELDS
SPACE
STEELS
WALLS
WATER COOLED REACTORS
WATER MODERATED REACTORS