Radiation and radiological equalities between natural uranium and radioactive waste in innovative two-component nuclear energy system

At the present time the innovative nuclear energy system on a new technology platform, a closed nuclear fuel cycle, is developed in Russia, provided that the impact of the spent nuclear fuel on the human health should not exceed that of natural uranium used for production of the fuel. As calculated, the total amount of uranium to be used in the nuclear energy systems to 2100 will be 541.7´103 tons and 7.523´103 tons of the long-lived waste will be accumulated. For the mass uranium/nuclear waste ratio the effective doses from uranium and the waste will be equal radiation equality) following 287 years of the spent fuel holding, while radiation risks will be equal (radiological equality) following 99 years of the spent fuel holding. With 2-fold uncertainty in doses assessment radiological equality will be achieved in about 270 years of the waste holding, while the radiation equality practically will not be achieved. With 30% uncertainty in doses assessment radiation and radiological equalities will be achieved in about 100 and 700 years of the waste holding respectively. If the nuclear waste is held more than 100-150 years, the main contributor of dose and radiation risk is 241Am. The content of americium isotopes in the waste mass is 0.23%. If the fraction of americium in the waste mass increases by 10 times, radiation equality will not be achieved even in 1000 years, while radiological equality will be achieved in 414 years, that is 315 years longer than the time needed to achieve radiological equality for common nuclear waste, 99 years. Due to separation of americium from the common waste it is possible to reduce the time needed to achieve radiological and radiation equalities between the depleted fuel and uranium. The principle of radiological equality can be used for justification of substantial reduction of time for radioactive waste holding. If thermal reactors only are used in nuclear power engineering, radiological equality may be achieved in more than 20,000 years of radioactive waste holding.