Study of a Slightly Enriched R Reactor Fuel by Means of a Pulsed Neutron Source; ETUDE D'UN REACTEUR A COMBUSTIBLE LEGEREMENT ENRICHI (RUBEOLE) A L'AIDE DE SOURCES PULSEES DE NEUTRONS

A BeO moderated reactor using slightly enriched uranium oxide as fuel was studied by the pulsed neutron source technique. The neutron lifetime was measured in two different cores without refiector, then attempts were made at the measurement of great negative reactivities introduced into the reactor under the following forms: decrease of the volume of the unreflected core, introduction of absorbing cadmium rods, removal of fuel at the periphery of the critical core while maintaining a constant height, and substitution of fuel elements by less reactive elements. In all cases, the results are compared with the data obtained by another type of experiment or by computation. (auth)