Radioactivity Specialists Ltd, Bryndwr, Christchurch, New Zealand.
J Environ Radioact. 2012 Aug;110:1-6. doi: 10.1016/j.jenvrad.2012.01.012. Epub 2012 Feb 1.
Radiopharmaceuticals make contributions of inestimable value to medical practice. With growing demand new technologies are being developed and applied worldwide. Most diagnostic procedures rely on (99m)Tc and the use of uranium targets in reactors is currently the favored method of production, with 95% of the necessary (99)Mo parent currently being produced by four major global suppliers. Coincidentally there are growing concerns for nuclear security and proliferation. New disarmament treaties such as the Comprehensive Nuclear-Test-Ban Treaty (CTBT) are coming into effect and treaty compliance-verification monitoring is gaining momentum. Radioxenon emissions (isotopes Xe-131, 133, 133m and 135) from radiopharmaceutical production facilities are of concern in this context because radioxenon is a highly sensitive tracer for detecting nuclear explosions. There exists, therefore, a potential for confusing source attribution, with emissions from radiopharmaceutical-production facilities regularly being detected in treaty compliance-verification networks. The CTBT radioxenon network currently under installation is highly sensitive with detection limits approaching 0.1 mBq/m³ and, depending on transport conditions and background, able to detect industrial release signatures from sites thousands of kilometers away. The method currently employed to distinguish between industrial and military radioxenon sources involves plots of isotope ratios (133m)Xe/(131m)Xe versus (135)Xe/(133)Xe, but source attribution can be ambiguous. Through the WOSMIP Workshop the environmental monitoring community is gaining a better understanding of the complexities of the processes at production facilities, and the production community is recognizing the impact their operations have on monitoring systems and their goal of nuclear non-proliferation. Further collaboration and discussion are needed, together with advances in Xe trapping technology and monitoring systems. Such initiatives will help in addressing the dichotomy which exists between expanding production and improving monitoring sensitivity, with the ultimate aim of enabling unambiguous distinction between different nuclide signatures.
放射性药物对医学实践做出了不可估量的贡献。随着需求的增长，新技术正在全球范围内得到开发和应用。大多数诊断程序都依赖于 (99m)Tc，并且目前使用反应堆中的铀靶是生产的首选方法，95%的必要 (99)Mo 母核目前由全球四个主要供应商生产。巧合的是，人们对核安全和核扩散的担忧日益增加。新的裁军条约，如《全面禁止核试验条约》（CTBT）正在生效，条约遵守情况核查监测正在加强。放射性药物生产设施产生的放射性氙气排放物（同位素 Xe-131、133、133m 和 135）在这种情况下令人担忧，因为放射性氙气是探测核爆炸的高度敏感示踪剂。因此，存在混淆源归属的可能性，放射性药物生产设施的排放物经常在条约遵守情况核查网络中被检测到。目前正在安装的 CTBT 放射性氙气网络具有很高的灵敏度，检测限接近 0.1 mBq/m³，并且根据运输条件和背景，能够从数千公里外的地点探测到工业释放的特征。目前用于区分工业和军事放射性氙气源的方法涉及同位素比值 (133m)Xe/(131m)Xe 与 (135)Xe/(133)Xe 的图，但源归属可能存在歧义。通过 WOSMIP 研讨会，环境监测界更好地了解了生产设施中过程的复杂性，生产界也认识到其运营对监测系统的影响及其核不扩散目标。需要进一步合作和讨论，同时需要改进 Xe 捕获技术和监测系统。此类举措将有助于解决生产扩大和监测灵敏度提高之间存在的二分法问题，最终目标是能够明确区分不同核素特征。
