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.

摘要

混凝土在核设施中起着重要的作用，可以防止辐射。然而，它的基本化学成分通常是未知的。对从 AMANDE-MIRCOM 放射防护和核安全研究所 (IRSN) 设施中提取的几个具体样品进行了分析。进行了各种模拟以评估 40 厘米厚混凝土墙后面的中子注量。这些模拟与使用 Bonner 球体光谱仪和中子测量仪进行的实验测量进行了比较。没有一组测试参数能够产生与所有实验结果准确匹配的模拟，但对几个参数的敏感性研究表明，三个最敏感的参数是氢含量、密度和混凝土不均匀性。为了提高模拟和测量之间的一致性，应进一步研究具体的不均匀性建模。然而，使用接近现实的混凝土组合物，尤其是氢含量，对于正确模拟中子传输至关重要。