The new approaches to the regulation of the radiation affects of NPPs on the population and the environment have led to the following important results:
- the admissible levels of radioactive emission are quite acceptable in terms of their effects on the population and the environment;
- the real levels of radioactive emission have been optimized and their further reduction would be economically unjustified;
- the task of NPPs for the near future is to preserve this level.
Much work has been done to this end by Russian nuclear power plants in the last 30-40 years. As a result they have found out the following:
- the radiation-hygienic situation has not changed since the launch of NPPs;
- the radiation situation at NPPs and in their nearby areas is within norm and is based on natural and cosmogenic radio-nuclides as well as global air pollution radio-nuclides produced by nuclear weapon tests and the Chernobyl accident;
- in the last years the real annual emission of radio-nuclides into the air does not exceed 30% of the relevant allowable levels specified by the existing sanitary rules for designing and operation of nuclear power plants;
- the real annual release of radio-nuclides into water is much lower than the standard level;
- the work of NPPs does not result in a rise in the average annual dose or significant radiation burdens on the population;
- the conservative annual irradiation dose to the critical groups of the population from gas and aerosol emissions by NPPs with WWER-1000-type reactors (PWR) is just 0.0001 microsievert, by NPPs with WWER-440- (PWR) and BN-600-type reactors (FBR) – 0.0005 microsievert and by NPPs with RBMK-type reactors (GMR) – 0.002 microsievert;
- the real releases into water depending on the type of an NPP and the type and size of a cooling pond hardly exceeds 0.001 microsievert.
Today, nuclear power plants have much lower effects on the environment than ordinary power plants (particularly, thermal power plants) (table 1).
Ecological consequences of the operation of thermal power plant and nuclear power plant with a capacity of 1GW
Consumption of fuel 5,900 ton a year 2,200 tons a year 2 600 000 m a year 200 tons a year – natural uranium Consumption of oxygen, thous. m/year 5,500,000 3,400,000 4,400,000 no Emmission, thous. tons/year Carbon oxide 10,000 6,000 2,000 - Sulfur oxide 124.4 84 - - Nitrogen oxide 34.2 21.9 23.6 - Solid waste, thous. tons/year 830 - - 0.03
The above table shows that thermal power plants have much bigger impacts on the environment than NPPs do.
Environmental costs incurred by NPP include expenses for protection and rational use of water resources (including payments to other enterprises for acceptance and treatment of waste waters), atmospheric air, environmental protection from adverse impact of production and consumption waste (including payment under contracts on transfer of waste to specialized organizations) and remediation of violated and contaminated lands.
NPP radiation impact on environment through its actual emissions and discharges of radioactive substances into atmospheric air and bodies of water is significantly below allowable values and does not exceed the minimum significant dose equal to 10 mSv per year. With such volume of emission of radionuclides to environment the radiation risk for population is guaranteed to be unconditionally acceptable (less than 10-6). It permits us to consider the actual level of emissions and discharges of NPPs as optimized.