Preliminary analysis of irradiation test of JOYO for SASS

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This calculation is evaluation of reactivity curve of a testing model of Self-Actuating Shutdown System(SASS) which gives data for application of permit of irradiation test in MK-III core of JOYO. The contents of this calculation are as follows. (1)Reactivity curve of testing model of SASS. Two dimensional RZ direct transport calculations are done on condition that the testing model is loaded in the radial center of core. Reactivity worth of the testing model of SASS is negative in the axial center region of core and positive in the region near the boundary between the core and the axial reflector. (2)Correction factor of reactivity worth of SASS for loading position. Correction factor of reactivity worth of SASS is calculated by two dimensional RZ transport code(TWOTRAN -II) and perturbation code(SN-PERT) because the testing model is planed to be loaded in the third row of core. The present structure of testing model is found to give 3 cent when it fall down from the full-out position.