Zohreh Gholamzadeh
Abstract
Simulation work provides valuable information on the behavior of different research reactor neutron analysis facilities. The present study considered neutron and secondary-gamma dose rate variations by applying a sapphire crystal inside the D channel in Tehran Research Reactor (TRR). The MCNPX computational ...
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Simulation work provides valuable information on the behavior of different research reactor neutron analysis facilities. The present study considered neutron and secondary-gamma dose rate variations by applying a sapphire crystal inside the D channel in Tehran Research Reactor (TRR). The MCNPX computational code was used to model the channel and its designed shield. Neutron and gamma dose rates distributions were calculated with a sapphire crystal modeling to investigate the neutron diffraction facility hall dose rates. The data from the dose rate simulations were compared with the experimental data available at a power of 4.2 MW from the research reactor. The comparison showed that there is very good conformity between two data series. The simulated neutron dose rate in front of the main shield overestimated the measurement data by 57% in closed-shutter situation and underestimated the measured data by 32% in open-shutter measurement situation. The investigation has shown that adjusting the crystal size to the channel size is considerably effective, especially at high leakage positions.
Zohreh Gholamzadeh; Ebrahim Abedi; Seyed Mohammad Mirvakili
Abstract
The management of high radioactive spent nuclear fuel (SNF) from research and power reactors has become a key topic of discussion in the nuclear communities. Metal casks are used for the management and disposal of spent fuel and all types of radioactive waste worldwide. The spent fuel assemblies-contained ...
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The management of high radioactive spent nuclear fuel (SNF) from research and power reactors has become a key topic of discussion in the nuclear communities. Metal casks are used for the management and disposal of spent fuel and all types of radioactive waste worldwide. The spent fuel assemblies-contained casks are stored in interim storage facilities. The present study aims to show the neutronic behavior and neutron/gamma dose rates of a designed hall for storage of the casks as a current technical, economic, safe and flexible solution, adaptable to any long and short-term SNF storage strategy. The hall structure was considered as ordinary concrete with an internal dimension of 5×6×5 m3. The concrete wall thickness was discussed to keep the dose rate limit of 10 μSv/h (neutron and gamma) at its external side when 25 casks are available inside the hall. ORIGEN and MCNPX computational codes were used to model the storage hall contained 25 Tehran Research Reactor spent fuel casks. The carried out calculations showed 30 cm thickness would fulfil total gamma and neutron dose rate limitation after the external surface of the concrete wall. When the hall contains 25 casks (any contains 16 55%-burnup 10-years cooled spent fuel assembly), maximum gamma and neutron dose rates at the external surface of the hall are 3.45 nSv/h and 3.45 μSv/h, respectively. In addition, the carried out calculations showed natural circulation of air could powerfully remove the deposited heat of neutron and gamma rays.
