炸药化学爆炸环境中模拟钚气溶胶源项研究

The safty study of weapons grade plutonium is a crucial orientation in fundamental engineering research for the manufacture and stockpile of nuclear warhead, which has been widely concerned by the nuclear power. The plutonium pit in warhead will be aerosolized and released into the atmosphere if the device is involved in an explosive chemical detonation. It is essential to determine the source-term data of plutonium aerosol during the diffusion calculation and hazard estimation, including the total dispersed mass and the cumulative distribution. Considering the high risk and toxic of plutonium aerosol, in this application a new research method is proposed in which several conventional metals will be used to simulate the plutonium aerosol source-terms in the circumstance of explosive detonation. During the research the source-terms of substitute metals will be compared with the data obtained by U.S. government in field detonation tests involving plutonium. In the preliminary source-term experiments with substitute metals an improvised device named colliding plane model will be used which is similar with the U.S.test unit. Then the optimized substitute metal can be obtained according to the contrastive analysis of source-term data and the simulative experimental method for the plutonium aerosol source-term in the circumstance of explosive detonation can be established. This method could be used in the subsequent source-term experiments in which several implosion type models with certain substitute metal would be used to simulate various chemical detonation scenarios of nuclear warhead. The source-term data obtained by these experiments will be significantly worthy for the diffusion calculation and environmental risk assessment of released plutonium aerosol after the chemical detonation events of nuclear explosives.

武器级钚材料的安全性研究是核战斗部研制和库存阶段重要的基础工程研究内容，业已受到各核大国的极大关注。在炸药化学爆炸环境中核战斗部的钚材料组件将气溶胶化并泄露至周边环境。弄清泄露钚气溶胶的源项参数（总质量及粒径分布）是开展钚气溶胶扩散模拟和环境危害评估的前提。鉴于直接开展钚气溶胶源项实验的高风险性，本申请项目提出利用常规金属材料进行炸药化爆条件下气溶胶源项实验、结合金属气溶胶生成机理及美国钚气溶胶源项数据开展事故性化爆模拟钚气溶胶源项研究的思路。通过平面对碰模型源项实验对比结果确定模拟钚气溶胶源项的优选材料以及炸药化爆环境中钚气溶胶源项的模拟实验方法。进而利用该方法开展基于各种核战斗部化爆事故场景的内爆加载模型钚气溶胶模拟源项实验。获得的源项数据将可为核战斗部炸药化爆事故后泄露钚气溶胶的扩散数值计算及环境危害定量评估提供必要的基础参考数据。

本项目建立了基于密封爆炸容器的金属气溶胶源项实验平台，通过开展炸药平面对碰加载条件下的多种金属气溶胶源项实验，并将结果与文献中美国ORC-DT核试验结果对比，确定了模拟钚气溶胶源项的优选材料，并建立了炸药化爆环境中钚气溶胶源项的模拟实验方法。针对优选的替代材料银，开展了多种爆压加载条件下的源项实验，进一步证实了银作为替代金属的可行性，同时发现了银气溶胶与钚类似的凝并、沉降等行为，并发现银气溶胶总量随爆压升高先增多后减少的变化趋势。为进一步研究核战斗事故条件下钚气溶胶源项特性，本项目设计了内爆加载概念模型，搭建了基于40 kg TNT当量密封爆炸塔的源项实验平台并完成了实验设计及条件准备。此外，本项目在国内首次开展了炸药化爆条件下开放空间银气溶胶扩散探索实验，掌握了相关的实验方法和测试技术，可为下一阶段钚气溶胶扩散模拟实验的开展提供必要的技术基础。.本项目获得的源项数据可为核战斗部炸药化爆事故后泄露钚气溶胶的源项释放及扩散评估提供必要的数据支持，同时可为人员疏散及应急响应措施的制定提供技术支撑。