The development of economy impels many countries to explore in the new energy sectors more and more frequent. Discovery and exploration of new energy sources will also lead humanity to enter a new developing pattern. Nuclear energy as a clean and modern economic energy can be mass produced, but also accompanied by a series of nuclear waste radioactive source pollution.The common radioactive sources in nuclear reactor project are α-rays, β-rays, γ-rays, neutrons, protons, heavy hydrogen nucleus and so on. They are with highly radioactivity, and do great harm to the human bodies. In addition, there are a number of radioactive substances, such as fission products (FP) radiation and their decay products (decay radiation) etc. Among these radioactive sources, γ-rays and neutrons is harmful to human bodies second to none, because both have stronger penetrating force. In addition to harm the human beings, radioactive source also can go through the surrounding objects so that makes the original non-radioactive objects become another radioactive medium. Therefore, when designing nuclear radiation shielding, γ-ray and neutron shielding should be first concerned.

 

For γ-rays, if the atomic number of radiation shielding material is higher, the radiation shielding effect will be better, such as iron, tungsten, lead, depleted uranium, concrete, brick, ionized water and so on. Especially for tungsten alloy, which is the best material, that can used as radiation shielding. But for neutrons, because of its cross section will change complexly with the elements and the ability of the neutron, so it doesn’t mean that the higher the material atomic number is,the greater the radiation shielding effect will be. On the contrary, a small atomic number elements can make neutron elastic scattering radiation dose significantly reduced. The study found that the tungsten alloy with 10cm thickness can shield the neutron radiation shielding rate of 93%.