Preliminary validation of computational model for neutron flux prediction of Thai Research Reactor (TRR-1/M1)

International Nuclear Science and Technology Conference 2014

Sabaibang, S.^1 ; Lekchaum, S.^1 ; Tipayakul, C.^2

Department of Applied Physics, Faculty of Science, King Mongkut's Institute of Technology Ladkrabang, Latkrabang, Bangkok, Thailand^1

Thailand Institute of Nuclear Technology (Public Organization), Ongkharak, Nakhon Nayok, Thailand^2

关键词: Activation measurements;    Activation techniques;    Computational model;    Flux measurements;    Irradiation facilities;    MCNPX simulations;    Self-powered neutron detectors;    Thermal-neutron flux;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/611/1/012006/pdf
DOI  :  10.1088/1742-6596/611/1/012006

来源: IOP

【 摘 要 】

This study is a part of an on-going work to develop a computational model of Thai Research Reactor (TRR-1/M1) which is capable of accurately predicting the neutron flux level and spectrum. The computational model was created by MCNPX program and the CT (Central Thimble) in-core irradiation facility was selected as the location for validation. The comparison was performed with the typical flux measurement method routinely practiced at TRR-1/M1, that is, the foil activation technique. In this technique, gold foil is irradiated for a certain period of time and the activity of the irradiated target is measured to derive the thermal neutron flux. Additionally, the flux measurement with SPND (self-powered neutron detector) was also performed for comparison. The thermal neutron flux from the MCNPX simulation was found to be 1.79×1013neutron/cm2s while that from the foil activation measurement was 4.68×1013neutron/cm2s. On the other hand, the thermal neutron flux from the measurement using SPND was 2.47×1013neutron/cm2s. An assessment of the differences among the three methods was done. The difference of the MCNPX with the foil activation technique was found to be 67.8% and the difference of the MCNPX with the SPND was found to be 27.8%.