Tritium and Kripton-85 in West Arctic Waters (Their Place in Study of the State of Spent Nuclear Fuel in Dumping and Accident Zones)

V. N. Soifer, V. A. Goryachev, V. K. Savchenko, D. V. Andreev, I. R. Barabanov, and E. A. Yanovich

The paper is devoted to the development of a methodology for monitoring the state of spent nuclear fuel (SNF) on the sea bottom and contains 3H database (2003) for modeling the process of radionuclide propagation from the source in dumping and accident zones in the Barents and Kara seas. Priority background data for 85Kr content in the near-bottom layer of the sea water are presented, along with permanent results (more than 900 days) from the experiment on the estimation of the fission products release rate (including 85Kr and 137Cs) from NSF (pellets of irradiated UO2). Methods and a technology on board the vessel to sample water (volume of 200 l) and to extract 85Kr and 137Cs for the radioactivity analysis (3H, also) in shore laboratories are developed. It is proved that 85Kr is the best indicator of the beginning of the fuel rod cladding failure and UO2 corrosion. A reliable and rather inexpensive methodology of periodic (once every 2–3 years) monitoring of SNF condition of the sea bottom in a dumping zone is proposed.