Sieh -~6", * oo fuel cycle will be plutonium-239 which has a 24,400 year half7 ee ae life. In other words, in 240,000 years the inventory of this hazardous material would be reduced by only a factor of 1000. @ue to natural radioactive decay: This material must be isolated from the environment in perpetuity. III. Existing Standards for Plutonium Exposure Radiation exposure standards have been established because radiation is known to produce cancer and genetic mutations in individuals irradiated. The mutations can in turn cause .genetic defects in subseguent generations. The intent of the exposure standards is to limit this biological damage. The magnitude of the biological effect has been shown to be related to the radiation dose. dose the greater the effect. Therefore, The higher the the primary radia- tion exposure standard is one that limits the radiaticn dose. This primary standard is generally referred to as the maximum permissible dose and is given in units of ren/yr. We shall discuss 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 he