The study of using liquid lead target for the accelerator driven subcritical reactor (ADSR) has been proposed by Nguyen Mong Giao, Vu Thi Diem Hang, Tran Minh Tien (International Journal of Modern Physics and Application. Vol. 2, No. 3, 2015). The calculations about neutron distribution, neutron fluxwith thorium fuel and thorium mixturehas been showed by Tran Minh Tien (Distribution of Neutrons from The Reaction (p, n) on the Liquid Lead Target in The Accelerator Driven System Reactor, J. Phys.: Conf. Ser. 1172 012066, 2019; Distributions of neutron flux from (p, n) reaction on the liquid lead target for accelerator driven subcritical reactor (ADSR), J. Phys.: Conf. Ser. 1324 012061, 2019). In this paper, the k effective factor is calculated with(Th233U)O2, (Th235U)O2and(Th238U)O2fuel mixture.

The paper presents the results of the calculation of neutron flux distribution and k effective factor in the ADSR with different reflector materials. Materials include graphite, Be, Y2O3, ZrO2. For each type of materials, the neutron flux distribution according to the height of the reactor, the radius, the neutron energy emitted, and k effective has been calculated. The results show that the maximum neutron flux and k effective factor is berium material as combined with Th-233U mixed fuel.