A comparative study of effective delayed neutron fraction

Fast-thermal coupled cores in zero power reactors: A demonstration of feasibility and pertinence for the ZEPHYR project

“…Even if it was studied to use fast-thermal coupled cores at an industrial scale (Avery, 1958), those configurations have been only loaded in ZPR where many experiments were carried out. Indeed, they represent a powerful tool to measure both total (Martin-Deidier, 1979) and separated (Fahrmann, 1981and Lehmann, 1986 cross sections of isotopes of interest, and other important parameters such as the ratio capture over fission (Bretscher, 1970) or kinetics parameters (Milosevic, 1995).…”

Determination of the neutron flux in the reactor zones with the strong neutron absorption and leakage

“…Experimental needs for the irradiation of samples and for the calibration of integral personal dosimeters in the fast neutron fields at the RB reactor initiated design and realisation of the coupled fast-thermal system HERBE [2] in late eighties of the last century. Characteristics of the HERBE system as well as the application examples are given in the references [2,3]. Further requirements related to the calibration of the absorbed neutron dose-rate-meters of large volume in the fast neutron fields have led to the realization of the RB reactor configuration with the inner neutron converter of cylindrical shell geometry and the inner diameter of 28 cm [4].…”

“…In august 2002 all the high-enriched fuel elements from both the VINČA reactors have been sent back to Russia, as a Serbia and Montenegro contribution to the RERTR Program (Reduced Enrichment for Research and Test Reactors). Therefore, the recent need for the calibration of RHP (Radio-Chemical Prototype) neutron dosimeters of large volume (about 1700 cm 3 ) in the fast neutron fields at the RB reactor up to 10 Gy of cumulative neutron dose required design of new core configuration using the available metal fuel elements of 2% and 0.714% of 235 U enrichment. Complex analyses done showed that different RB reactor core configurations with 2% and 0.714% fuel elements combined with the existing neutron converters and filters, suitable for the RB reactor core configurations with 80% enriched fuel elements, could not provide the criticality of the system against the delayed neutrons even at the maximal moderator height in the reactor tank (about 170 cm, that corresponds to the total amount of the heavy water available).…”