Neutronic Analysis of SAMOP Reactor Experimental Facility Using SCALE Code System

The Subcritical Assembly for ⁹⁹Mo Production (SAMOP) rector is considered a suitable candidate to produce ^99mTc isotope on a small scale. The design of SAMOP reactor using uranyl nitrate (UN) as fuel has been studied at National Nuclear Energy Agency. The neutronic analysis of the SAMOP Experimental Facility will be reported in this paper. The SAMOP reactor core design consists of an annular tube containing UN surrounded by the ring of UN tubes, and a fuel tube absorber follower is inserted in the center of the core. The work covers the criticality calculation to secure the sub-criticality level and neutron flux distribution analysis. The computational method is using SCALE computer code. The analysis result shows that for the required neutron multiplication factor of 0.98 to 0.99 (sub-criticality level) can be achieved by a combination of fuel (UN) height in the annular tube of 38 cm surrounded by 5 – 8 of UN tubes in the ring. For the UN height in the annular tube of 39 cm, it should be surrounded by 3 – 6 of UN tubes in the ring.