059 放射性废物的危险
Danger of Radioactive Waste
（https://www.nuclear-power.com/）
放射性废物的危险
Radioactive waste dangers are determined by many factors, since it is very important to note that there are many types of radiation. Dangers are usually determined by:
放射性废物的危险是由许多因素决定的，因为非常重要的是要注意到有许多类型的辐射。危险通常由以下因素决定:
- Type of Radiation. Unstable isotopes decay spontaneously through various radioactive decay pathways, most commonly alpha decay, beta decay, gamma decay or electron capture. We have to take into account to which type of radiation (and its energy) are you exposed. For example, alpha radiation tend to travel only a short distance and do not penetrate very far into tissue if at all. Therefore, alpha radiation is sometimes treated as non-hazardous, since it cannot penetrate surface layers of human skin. This is naturally true, but this is not valid for internal exposure by alpha radionuclides. When inhaled or ingested, alpha radiation is much more dangerous than other types of radiation. In short, the biological damage from high-LET radiation (alpha particles, protons or neutrons) is much greater than that from low-LET radiation (gamma rays).
- 辐射类型。不稳定的同位素通过各种放射性衰变途径而自发地衰变，最常见的是阿尔法衰变、贝塔衰变、伽马衰变或电子俘获。我们必须考虑你暴露在哪种类型的辐射(及其能量)下。例如，阿尔法辐射往往只传播很短的距离，即使完全穿透组织也不会穿透很远。因此，阿尔法辐射有时被认为是无害的，因为它不能穿透人体皮肤的表层。这自然是正确的，但这不适用于阿尔法放射性核素的内照射。当吸入或摄入时，阿尔法辐射要比其他类型的辐射危险得多。简而言之，高线性能量转换照射（阿尔法粒子、质子或中子）对生物的损害远远大于低线性能量转换照射照射（伽马射线）。
- Intensity. Intensity of ionizing radiation is a key factor, which determines health effects from being exposed to any radiation. It is similar as being exposed to heat radiation from a fire (in fact, it is also transferred by photons). If you are too close to a fire, the intensity of thermal radiation is high and you can get burned. If you are at the right distance, you can withstand there without any problems and moreover it is comfortable. If you are too far from heat source, the insufficiency of heat can also hurt you. This analogy, in a certain sense, can be applied to radiation also from ionizing radiation sources. We must note that, radiation is all around us. We are continually exposed to natural background radiation and it seems to be without any problem.
- 强度。电离辐射强度是一个关键因素，它决定了暴露于任何辐射时对健康的影响。这类似于暴露在火的热辐射中（事实上，它也是通过光子传输的）。如果你离火太近，热辐射的强度很高，你可能会被烧伤。如果你处于正确的距离，你可以承受得住而没有任何问题，而且是舒适的。如果你离热源太远，热量不足也会对你造成伤害。在某种意义上，这个类比也适用于来自电离辐射源的辐射。我们必须注意，辐射无处不在。我们持续暴露在天然本底辐射下，而且似乎没有任何问题。
- Chemical properties of the radioactive material. Chemical properties are key factor for possible internal exposure. For example, Sr-90, Ra-226 and Pu-239 are radionuclides known as bone-seeking radionuclides. These radionuclides have long biological half-lives and are serious internal hazards. Once deposited in bone, they remain there essentially unchanged in amount during the lifetime of the individual. These radioactive chemical elements have to be isolated from the environment as long as they are radioactive. On the other hand, in case of artificial tritium ingestion or inhalation, a biological half-time of tritium is 10 days for HTO and 40 days for OBT (organically bound tritium) formed from HTO in the body of adults.
- 放射性材料的化学性质。化学性质是可能受到的内照射的关键因素。例如，放射性核素Sr-90、Ra-226和Pu-239被称为亲骨性放射性核素。这些放射性核素具有很长的生物半衰期，以及严重的内部危害。一旦沉积在骨骼中，其数量在个体的一生中基本保持不变。只要这些放射性化学元素是放射性的，就必须把它们从环境中分离出来。另一方面，在人工摄入或吸入氚的情况下，氚水（HTO）中氚的生物半衰期为10天，由成人体内氚水（HTO）形成的OBT（有机结合氚）的生物半衰期为40天。
As a result, radioactive waste management assumes different approaches for different types of radioactive waste.
因此，放射性废物管理要对不同类型的放射性废物采用不同的方法。
注：
（以下内容来自百度百科）
氚水
氚是氢的一种放射性同位素，符号为3H，质量数为3，在天然氢中，氚的含量为1×10-15%。它的原子核由一个质子和二个中子组成，性质与氢很相似。
通过同位素交换作用，3H与H2O中H交换形成氚水HTO。绝大部分的3H以HTO形式存在。
【以上3，-15为上标，2为下标】
（待续）
