Abstracts and Available Papers Presented at the
2004 International RERTR Meeting

WHAT THE DIFFERENCE TO USE LEU AND HEU FUEL ELEMENTS SEPERATELY OR TOGETHER IN A RESEARCH REACTOR

ŞADİ KAYA
Çekmece Nuclear Research and Training Center P.K. 1, Havaalanı, 34831-İstanbul

GÜLSEN ÜSTÜN
Çekmece Nuclear Research and Training Center P.K. 1, Havaalanı, 34831-İstanbul

ABSTRACT
 

Concerning of nuclear material safety, most of the research reactors are advised to shift from HEU (high enriched-%93 U235) to LEU (low enriched-%20 U235) fuel elements. When LEU and HEU fuel elements are to be used together in a research reactor, some design and safety problems are encountered. According to use of the reactor, some research reactors such as MTR type may not show any considerable difference for HEU or LEU fuel elements, but the efficiency of radio-isotop production generated by thermal neutron interaction may decrease about twenty-thirty percent when LEU fuel elements are used. Here, fine mesh-sized 3D neutronic analysis of TR-2 research reactor is presented to indicate the arising problem when LEU end HEU fuel elements are used together in a research reactor. Partial thermohydraulic analysis of the reactor is also given to show the betterness of the LEU fuel element design. However, there might be some points that should be noticed for safer operation of plate type fuelled research reactors.

---

---