RADIOACTIVE CONTAMINATION OF THE ENVIRONMENT IN THE AREAS OF LOCATION OF OBJECTS OF THE NUCLEAR FUEL CYCLE
Ministry of Atomic Energy,
I.I. KRYSHEV, T.G. SAZYKINA
SPA "Typhoon", Obninsk
The entry of radionuclides into the environment occurs at all stages of the Nuclear Fuel Cycle:
during the extraction and reprocessing of uranium ore, production of fuel elements, operation of nuclear
reactors, reprocessing of spent fuel, and burial of radioactive wastes. This report shows the generalization
of data in the areas of location of objects of the nuclear fuel cycle (NFC) in the territory of Russia.
Generalized data on the quantities and radionuclide composition of releases to the atmosphere from nuclear facilities of the Ministry of Atomic Energy (Minatom) of Russia are presented in Tables I and II
[1, 2]. Among natural radionuclides, 222 Rn i s a majo r contributo to the activity of atmospheri c release (about 420 TBq/year). Among artificial radionuclides, isotopes of inert radioactive gases (IRG) have the greatest activity in atmospheric releases of enterprises of Minatom (about 28 PBq). Releases of tritium amount to 410 TBq/year. An appreciable contribution to the IRG activity is made by gas-aerosol releases from NPPs. Athe present time, 29 power units with a total installed capacity of 21.242 GWt (el.) are functioning in Russia. Table DI presents normalized estimates of radioactive releases from NPPs in Russia in the period 1985-1993. In all, gas-aerosol releases from NPPs with the RBMK-type reactors are distinctly higher than those with the WWER-type reactors. There is a tendency for a decrease in the activity of atmospheric releases in the period 1991-1993, as compared to the preceding period 1985-1990, which is associated with the improvement of the gas purification system at NPPs.
Table IV presents die radionuclide composition of liquid discharges from enterprises of Minatom in 1992-1993 to die surface waters [1, 2]. In 1992, die total activity of liquid discharges amounted to 11.5 PBq. A major contribution to this activity was made by short-lived radionuclides (^Na, 3ISi and **Cu) with a half-life less than 24 hrs, which accounted for about 81%, and by radionuclides with a half-life from 24 hrs to 1 month (°P, 31 Cr , ^Mn "'As 239Np an d otiiers) whic h accounte fo abou t 18% . Th long-lived nuclides with a halflife over 1 year amounted to 9 TBq or less than 1 % of die total activity of discharges. A major contribution to the activity of long-lived nuclides was made by tritium, "Co, ""ïlu, ^Sr, 137Cs and others In 1993 a considerabl decreas was observe in the of radioactiv discharges to the surface waters, as compared to 1992. In 1993, the total activity of liquid wastes amounted to about 1.2 PBq, i.e. decreased by an order of magnitude, as compared to 1992. This decrease in die activity of radionuclide discharges was due to die reduced output at die enterprises of Minatom and removal from service of a number of nuclear facilities.
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