PULSED NEUTRON EXPERIMENTS ON SUBCRITICAL HEAVY WATER NATURAL URANIUM LATTICES

Journal Article · Sat Jun 01 04:00:00 EDT 1963 · J. Nucl. Energy, Pt. A & B

DOI:https://doi.org/10.1016/0368-3230(63)90114-9· OSTI ID:4684581

Meister, H

Prompt neutron decay in several subcritical D/sub 2/Omoderated natural uranium lattices is investigated by the pulsed technique. Employing various detector positions inside the multiplying medium, a separation of flux harmonics is achieved by means of a Fourier transform. From the modal decay curves the prompt neutron decay constant alpha is found as a function of geometrical buckling B/sup 2/. In the lower buckling region, B/sup 2/ < 25 m/sup -2/, experimental alpha vs. B/sup 2/ curves agree with simple two-group calculations on the basis of lattice parameters determined in exponential experiments. Deviations for higher B/sup 2/ are shown to be produced by spectrum shifts towards lower neutron energies. In addition, the change of radial buckling DELTA mu /sup 2/ caused by cadmium rods fully inserted into the latiice is determined. The results are in agreement with stationary experiments as well as two-group calculations. With single fuel rods withdrawn from the lattice, however, the corresponding radial buckling change DELTA mu /sup 2/ turns out to be strongly dependent on the buckling of the axial flux distribution. (auth)

• Research Organization: Kernforschungszentrum Karlsruhe, Ger.
• NSA Number: NSA-17-031692
• OSTI ID: 4684581
• Journal Information: J. Nucl. Energy, Pt. A & B, Journal Name: J. Nucl. Energy, Pt. A & B Vol. Vol: 17
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

BUCKLING
CADMIUM
CONFIGURATION
CONTROL ELEMENTS
CRITICALITY
DECAY
EXPONENTIAL PILES
GROUP THEORY
HEAVY WATER MODERATOR
NATURAL URANIUM FUEL
NEUTRON FLUX
NEUTRONS
PROMPT NEUTRONS
PULSES
REACTOR TECHNOLOGY
RODS
SPECTRAL SHIFT