fuel cycle will be plutonium-239 which has a 24,400 year halflife. In other words, in 240,000 years the inventory of this hazardous matcrial woulji be reduced by only a factor of 1009 due to natural radioactive decay. This matcrial must be isolated from the environment in perpetuity. Itt. Existing Standards for Plutonium Cxposure Radiation exposure standards have been established because radiation is known to produce cancer and genetic mutations in individuals irradiated. in turn cause genetic defects The mutations can in subsequent generations. ~ The macnituce of the piological effect has >een shown to be related to the radiation dose. dose the greater the effect. The higher the Therefore, the primary radia- cion exposure standard is one that limits the radiation dose. v~ damage. te wee. The intent of the exposure standards is to limit this biological This primary standard is generally referred to as the maximum permissible dose and is given in units of rem/yr. the nature of this unit subsequently. An individual can be exposed to radiation from sources that are external to his body as, for example, an X-ray machine or from radionuclides which emit X-ray like radiation deposited on the ground (this occurred with fallout from nuclear weapon tests). Alternately, an individual can be tree Ct oe tee . we es were We shall discuss