Interim Storage of the Dalat Nuclear Research Reactor: Radiation Safety Analysis

Abstract

Radiation safety analysis of a new interim storage of the Dalat Nuclear Research Reactor (DNRR) for keeping spent high enriched uranium (HEU) fuel bundles during the core conversion to low enriched uranium (LEU) fuel had been performed and presented. The photon source and decay heat of the spent HEU fuel bundles were calculated using the ORIGEN2.1 code. Gamma dose rates of the spent fuel interim storage were evaluated using the MCNP5 code with various scenarios of water levels in the reactor tank and cooling time. The radiation safety analysis shows that the retention of 106 spent HEU fuel bundles at the interim storage together with a core of 92 LEU fuel bundles meets the requirements of radiation safety. The results indicate that in the most severe case, i.e., the complete loss of water in the reactor tank, the operators still can access the reactor hall to mitigate the accident within a limited time. Particularly, in the control room, the dose rate of about 1.4 μ Sv / h is small enough for people to work normally.

Determination of the Activity Inventory in the Structural Components of the Dalat Nuclear Research Reactor for Its Decommissioning Planning

“…e concrete structure of the biological shield for the reactor, which is octagonal-shaped with a width of 6.96 m, a length of 8.63 m, and a height of 6.55 m, has an average density of 2.35 g/cm 3 , with a density of 3.5 g/cm 3 around the thermal column [1,3].…”

“…Distilled light water is used as coolant, neutron moderator, re ector, and radiation shielding. After its reconstruction and upgrading, since March 1984, the reactor has been o cially put into operation for the purposes of radioisotope production, neutron activation analysis, fundamental and applied research, and manpower training but without having a preliminary decommissioning plan [1][2][3].…”

Overview on Radiation Damage Effects and Protection Techniques in Microelectronic Devices

“…When exposed to radiation for a long time, microelectronic devices accumulate absorbed doses, leading to device performance degradation, such as changes in threshold voltage, reduction in carrier mobility, and damage to oxide layers. Tis efect is crucial for space missions because of the radiation in space environments [9]. Various space exploration missions conducted by NASA often need to consider the TID efect on scientifc instruments and communication systems.…”