During a severe nuclear accident leading up to core melting, molten corium–concrete interaction (MCCI) and core-coolant water reaction both release large amounts of hydrogen (H2) gas in the containment atmosphere. According to the Shapiro–Moffette ternary diagram and depending on local partial pressures of H2, air, and water vapor, deflagration/detonation may occur with potential deleterious impact over equipment and structures. CO and CO2 are also of interest, as revealing gases for MCCI. Pressurized Water Reactors (PWRs) of French Nuclear Power Plants (NPPs) are equipped with passive autocatalytic recombiners (PARs), partly mitigating the H2 risk. However, the H2-risk management strategy may be significantly improved by performing in situ monitoring of H2, O2, N2, H2O, CO, and CO2 partial pressures at several locations inside the containment, to account for potential local combustion risk. Raman spectrometry (RS) involves only one laser and spectrometer equipped with a 2-D charge-coupled device (CDD). Raman probes are chemically selective and may be radiation-hardened. Custom-made fiber-coupled Raman probes, linked with a readout unit, were qualified in a climatic chamber, a flame-propagation tube, a 60Co irradiation cell, a 3-D shaking table, a steam jet and the MISTRA facility (1/10 reduced-scale containment mock-up dedicated to thermo-hydraulic tests).

中文翻译：

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通过光纤耦合拉曼光谱进行现场气体监测，用于严重核事故期间核安全壳中的 H2 风险管理

在导致堆芯熔化的严重核事故期间，熔融的真皮-混凝土相互作用 (MCCI) 和堆芯-冷却剂水反应都会在安全壳大气中释放大量氢气 (H2)。根据 Shapiro-Moffette 三元图并根据局部 H2、空气和水蒸气的分压，可能会发生爆燃/爆炸，并对设备和结构产生潜在的有害影响。作为 MCCI 的揭示气体，CO 和 CO2 也是令人感兴趣的。法国核电站 (NPP) 的压水反应堆 (PWR) 配备了被动自催化复合器 (PAR)，从而在一定程度上降低了 H2 风险。然而，通过在安全壳内的几个位置对 H2、O2、N2、H2O、CO 和 CO2 分压进行现场监测，可以显着改进 H2 风险管理策略，以考虑潜在的局部燃烧风险。拉曼光谱 (RS) 仅涉及一台配备有二维电荷耦合器件 (CDD) 的激光器和光谱仪。拉曼探针具有化学选择性并且可能是辐射硬化的。定制的光纤耦合拉曼探头与读出装置相连，在气候室、火焰传播管、60Co 辐照室、3-D 振动台、蒸汽射流和 MISTRA 设施（1/ 10 个缩小规模的安全壳模型，专用于热液压测试）。