Conceptual Design of a Fast Periodically Pulsed Reactor

The IBR-2M pulsed nuclear reactor operating at the JINR Laboratory of Neutron Physics delivers an intense neutron flux on the order of 10 13 n/(cm 2 s). By the end of the 2030s, it will outlive its useful lifetime and will have to be replaced with a new machine. The alternative neutron sources proposed so far require extensive and costly R&D efforts, and positive results cannot be guaranteed. In this paper, we present a conceptual design of the IBR-4 reactor running on plutonium-dioxide fuel which is aimed to replace the IBR‑2M machine as a neutron source. This design fully builds on proven technical solutions tested at other nuclear facilities and, therefore, requires no extensive R&D and guarantees reliable and safe operation of the proposed neutron source. Running at a 5-MW power and a pulse repetition rate of 5 Hz, IBR-4 will deliver a thermal-neutron flux of 5.8 × 10 13 cm –2 s –1 . When running at a 10-MW power and a pulse repetition rate of 10 Hz, the proposed source is expected to deliver a record-high thermal-neutron flux on the order of 1.1 × 10 14 cm –2 s –1 .