Concrete Modeling for Neutron Transport and Associated Sensitivity Studies Performed at the AMANDE-MIRCOM Facility

Abstract

Concrete plays a major role in nuclear facilities as protection against radiation. However, its chemical composition, which is fundamental, is often unknown. Several concrete samples, extracted from the AMANDE-MIRCOM Institute for Radiological Protection and Nuclear Safety (IRSN) facility, were analyzed. Various simulations were performed in order to evaluate the neutron fluence behind a 40-cm-thick concrete wall. These simulations were compared to experimental measurements performed with a Bonner sphere spectrometer and a neutron survey meter. No set of parameters tested was able to produce a simulation accurately matching all the experimental results, but sensitivity studies on several parameters highlight that the three most sensitive parameters are the hydrogen content, the density, and the concrete inhomogeneity. To improve the agreement between the simulations and the measurements, the concrete inhomogeneity modeling should be studied further. Nevertheless, using concrete compositions that are close to reality, especially for hydrogen content, is crucial to correctly simulate neutron transport.

Keywords:

• Concrete
• shielding
• modeling
• neutrons
• radiation protection

Acknowledgments

The author deeply thanks Véronique Lacoste for the provided experimental results and analysis, Vincent Gressier and Isabelle Duhamel for extensive discussions and numerous improvements of this manuscript, and Paul Kloppenberg for his valuable help in upgrading the English quality of the text. This work was supported by IRSN (Institut de Radioprotection et de Sûreté Nucléaire).

Notes

^a “Concrete, Barytes-limonite [Material Number] 77”; “Concrete, Boron Frits-baryte [Material Number] 78”; “Concrete, Colemanite-baryte [Material Number] 79”; “Concrete, Luminite-colemanite-baryte [Material Number] 87”; and “Concrete, Luminite-Portland-colemanite-baryte [Material Number] 88” (Ref. 1).

^b “Concrete, Los Alamos (MCNP) [Material Number] 86” and “Concrete, Magnuson [Material Number] 92” (Ref. 1).

^c “Concrete, Ferro-phosphorus [Material Number] 80”; “Concrete, Iron-limonite [Material Number] 83”; “Concrete, Limonite and Steel [Material Number] 85”; “Concrete, M-1 [Material Number] 89”; “Concrete, Magnetite [Material Number] 90”; “Concrete, Magnetite and Steel [Material Number] 91”; and “Concrete, MO [Material Number] 93” (Ref. 1).

^d “Concrete, Ordinary (NBS 03) [Material Number] 95”; “Concrete, Ordinary (NBS 04) [Material Number] 96”; “Concrete, Portland [Material Number] 98”; and “Concrete, Rocky Flats [Material Number] 100” (Ref. 1).

^e “Concrete, Hanford Wet [Material Number] 82”; “Concrete, Portland [Material Number] 98”; Concrete, Regular [Material Number] 99”; and “Concrete, Serpentine [Material Number] 101” (Ref. 1).