Derivation of radiological source term of Korean Design System-Integrated Modular Advanced ReacTor (SMART)

In this work, a study has been conducted to carry out a qualitative analysis for the evaluation of radiation exposure from SMART reactor. Since SMART reactor is large LOCA proof therefore, a small break has been considered as a Design Basis Accident (DBA) with continuous leakage of coolant. The onsite and offsite source term of different isotopes have been evaluated and compared with CHASNUPP-1 and KORI-1 NPPs. For this purpose, a kinetic model has been developed and implemented in MATLAB to carry out the simulation of onsite and offsite source term. The developed model uses ORIGEN 2.2 core inventory as a subroutine. The coolant inventory has been evaluated with 0.25% failed fuel fraction and compared with CHASNUPP-1 and KORI-1 NPPs. A contradiction from Kim and Kang (1999) work has been observed with a significant difference in core and coolant inventory calculations. Noble gases source term of SMART reactor has been found 18.90 g whereas 0.0043 g of iodine source term has been evaluated within a day with a major contribution of 131I with 0. 0032 g. However, 5.3 g of cesium source term has been found to release from SMART reactor with a major contribution of 135Cs, which contributes 4.40 g within a day. 140Ba has a dominant contribution in offsite source term with 0.00409 g during SBLOCA with 1% core damage fraction. The evaluated source term of SMART reactor is four times less than KORI-1 and 1.5 times less from CHASNUPP-1 NPP under same conditions.