Study on Kinetic Characteristics of Krypton and Xenon radioactive source term in molten salt reactor

Abstract

A numerical simulation program for the dynamic distribution of krypton and xenon with flow and on-line removal function was established for primary loop system of molten salt reactor(MSR) Based on Mathe-matica7.0.The simulation results of the static burnup was compared with ORIGEN-S program, and the deviation is less than 10%, which is in good agreement.The distribution and dynamic characteristics of krypton and xenon in the primary loop system were analyzed under the flow regionalization and online removal model.The results show that,the static burnup model underestimates the total 135Xe activity about 6.61% in the system, and the total activity of krypton and xenon in the system is underestimated by about 1.46%.Under the maximum removal fraction, the total activity of krypton and xenon in the exhaust gas system is 1.84×1016Bq, of which 83mKr, 85mKr, 87Kr, 88Kr, 133Xe, 135Xe and 138Xe account for about 95.6%.The total activity of krypton and xenon in the primary loop system is 2.64×1014Bq, of which 138Xe, 135mXe, 134mXe, 87Kr and 83mKr account for about 93.6%.The numerical simulation method and the conclusion consistent with the actual physical laws.Dynamic distribution, evolution and migration characteristics of krypton, xenon and these precursor in the primary loop in the molten salt can be simulated more accurately compared to static burnup model.The analysis results can provide a theoretical basis for the management scheme of airborne source termsthe cooling design of the radioactive exhaust system and the source term analysis in accident conditions for the molten salt reactor.