Assessment of radioecological impact from prospective geological disposal facility of radioactive waste within an operational period

Potential radiation doses to humans and biota were estimated from a prospective radioactive waste (RW) geological disposal in the vicinity of Mining and Chemical Combine (Zheleznogorsk, Siberia, Russia). Operational phase of the disposal filling with highly radioactive wastes is considered as critical period with highest potential impact on humans and the environment than comparing with a post-closure period. Atmospheric releases of radionuclides from ventilation systems of the open geological RW disposal facility are expected to be a main source of radiation impact on the local population and the environment. Doses to local population and reference non-human biota in the vicinity of disposal facility were calculated for different scenarios of facility operation. Three scenarios of potential atmospheric releases from open disposal facility were calculated depending on disposal material: spent nuclear fuel and irradiated graphite; spent fuel without graphite; vitrified radioactive waste. For the most conservative scenario, estimated doses to local population from atmospheric releases did not exceed 0.01 mSv/year with major contributions from 14C, 3H and 222Rn (distance from the facility >500 m); technogenic doses to reference biota did not exceed 0.05 microGy/h that was below radiation background levels. Results of radioecological assessment demonstrate low levels of technogenic exposures of local population and the environment in the vicinity of prospective geological disposal of radioactive wastes (near Zheleznogorsk, Siberia). Conclusion was made that radioecological situation in the local area of the RW geological facility during its operation period is expected to be normal both for humans and the environment.