ABSTRACT NO2 and NO generated during a boiling and drying accident, which affects the release of volatilized radioactive Ru into the atmosphere, were examined using various samples including simulated high-level liquid waste and a thermogravimetric analyzer. NO2 and NO in the gas flowing out of the analyzer were measured separately using a NOx analyzer equipped with NO2 and NO sensors. The samples were heated to 600°C at constant heating rates of mainly 0.2 and 1°C min−1 that was adopted taking into account the decay heat of high-level liquid waste. It was found that under 180°C some nitrates in the liquid waste mainly separated their nitrate groups as HNO3 without generating NOx (a mixture of NO and NO2) and above 300°C the residual HNO3 in the waste participated in thermal decomposition generating NOx. The generation rates of NO2 and NO were obtained as a function of time using Arrhenius type equations, and the O2 rate was derived from these equations using the stoichiometry of the reactions that generate NO2, NO, and O2.

中文翻译：

---

某后处理厂高放废液沸腾干燥事故：利用模拟废物检测NO2和NO的生成

摘要 在沸腾和干燥事故中产生的 NO2 和 NO 会影响挥发的放射性 Ru 释放到大气中，使用各种样品（包括模拟高放废液和热重分析仪）进行了检测。使用配备有 NO2 和 NO 传感器的 NOx 分析仪分别测量流出分析仪的气体中的 NO2 和 NO。将样品以 0.2 和 1°C min-1 的恒定加热速率加热至 600°C，考虑到高放废液的衰变热。研究发现，在180°C以下，废液中的一些硝酸盐主要将其硝酸根基团分离为HNO3，不产生NOx（NO和NO2的混合物），而在300°C以上，废液中残留的HNO3参与热分解生成NOx。