Core Management of the Dalat Nuclear Research Reactor

The Dalat nuclear research reactor (DNRR) is a pool-type research reactor which was reconstructed from the 250 kW TRIGA-MARK II reactor. The reconstructed reactor reached its initial criticality in November 1983 and attained its nominal power of 500 kW in February 1984. The DNRR uses Russian fuel assemblies, type WWR-SM. The first fuel reloading was executed in April 1994 after more than ten years of operation with 89 fuel assemblies. Research on core management of DNRR with the purpose of maintaining safe operation and effective utilization of reserve fuel assem- blies is being carried out at the Nuclear Research Institute. Calculations of fuel burn-up for the Dalat nuclear research reactor are carried out based on the cell calculation program WIMS and two diffusion calculation programs HEXAGA and HEXNOD. Experimental measurement of fuel burn-up for the Dalat nuclear research reactor was realized by a measurement method of long-life isotopes from fission products. Optimum second fuel reloading and future refuelling for DNRR have been gained. A second fuel reloading for the Dalat nuclear research reactor was realized in March 2002. After reloading the working configuration of the reactor, the core consisted of 104 fuel assemblies. Research results for future refuelling for DNRR show that with 36 reserve fuel assemblies, the reactor will be operated for at least 17 851 h at nominal power since the second fuel reloading. (author)