19 
2 
Cumulative deposit of 9°Sr on earth’s surface (MCI) 
le eine cet a 
1960 1970 1980 1890 2000 2010 2020 2030 2640 
Year 
¥Fieure 1.—The amount of 9°Sr on the earth’s surface reached a maximum during 
1966-1967 and will decline exponentially with a half-life of 28 years unless at- 
mospheric testing is resumed. The level of ®7Cs deposited is approximately 
1.7 times that shown for Sr. 
Source: Rice, T. R. and D. A. Wolfe. Radioactivity—Chemical and Biological Aspects. In ‘Impingement 
-of Man on the Oceans’’ (Hood, D. W., ed.). New York, Wiley-Interscience, 1971, p. 333. 
_ Nuclear power plants generate small amounts of radioactive wastes 
which are released into the environment. The two main sources of 
this radioactivity are uranium fission products which escape the fuel 
cladding and radionuclides resulting from activitation of corrosion 
products. Although carefully controlled, some radioactive isotopes 
(mostly tritium and the noble gases) are released in water or vapor. 
Table XIV lists an estimate of the radioisotopes that would be released 
annually by a 1050 megowatt pressurized-water reactor planned for 
Burlington County, New Jersey. Nuclear fuel production plants and 
plants for reprocessing nuclear fuels are also responsible for discharging 
low levels of radioactivity. 
The recommendations of the International Commission on Radio- 
logical Protection (ICRP) * are universally used as guides for regula- 
24 International Commission on Radiological Protection. Recommendations of the International Commission 
on Radiological Protection (adopted September 9, 1958), New York. Pergamon Press, vi + 18 p. 
