Ponente
Descripción
As a complementary purpose of materials irradiation, a collimated neutron beam from the IFMIF-DONES Test Cell (TC) will be supplied to Complementary Experiments (CER) for the users to conduct a variety of neutronics experiments. This work includes the results of the neutronic modeling and analyses of the neutron tube and the Neutron Beam (NB) shutter with the open and closed design configurations of the NB shutter. Methodologically, the modeling has been assisted with the SuperMC code [1] for CAD-to-MCNP model conversion. The neutron and photon radiation transport has been performed by the McDeLicious-17 code package – an MCNP source extension that simulates the deuteron-lithium (d-Li) nuclear reactions. The neutron cross-sections library FENDL-3.1d has been used in calculations. The neutronics results were normalized to a 125 mA deuteron beam of 40 MeV deuterons impinging the lithium target. Neutrons born in TC were collimated by the neutron tube and NB shutter to enter CER by passing through the 6.4-m thickness of the removable biological shielding blocks (RBSB) and bucket made of heavy and ordinary concrete as reported in [2]. Correspondence to the radiation zoning of the rooms around TC has been checked and confirmed that the TC bucket made of ordinary concrete satisfies the planned zoning, in some cases with a safety factor. When the neutron beam passes through the open shutter, the Dose Rate (DR) in the CER exceeds 100 mSv/h. Therefore, for the open NB design, CER is classified as the Red (forbidden) radiation zone. By closing the NB shutter, DR in CER drops lower than 1 mSv/h, allowing set CER to the Yellow (limited regulated) radiation zone defined by the DR in the range (10 < DR <1000) microSv/h. Neutron fluxes and neutron energy spectra have been compared with the neutronics results presented in the work [3].
Additionally, this work includes neutronics analyses for the polyethylene (PE) moderator installed in CER at a 10-cm distance from the open central channel of the NB shutter. Maps of total neutron flux and broad energy groups have been calculated for the PE moderator and open NB shutter.
References:
[1] Y. Wu, “Multi-functional Neutronics Calculation Methodology and Program for Nuclear Design and Radiation Safety Evaluation”, Fusion Science and Technology 74 (2018) 321-329.
[2] A. Serikov et al., “ENS-2.2.4.1-T013-03: Performance and optimization analyses for the TC and surrounding rooms as requested for systems design updates and specific evaluations”, WPENS Technical Meeting #13 Neutronics Session, 9 June 2022, Granada, Spain.
[3] J. Hirtz et al., “Neutron availability in the Complementary Experiments Hall of the IFMIF-DONES facility”, Fusion Engineering and Design 179 (2022) 113133, https://doi.org/10.1016/j.fusengdes.2022.113133
