TRITIUM AND KRYPTON-85 IN THE WEST ARCTIC WATERS (THEIR ROLE IN THE STATE OF SPENT NUCLEAR FUEL IN DUMPSITES AND ACCIDENT ZONES)

摘要

A methodology of monitoring the state of spent nuclear fuel (SNF) on the sea bottom is developed. Data are obtained on tritium ~3H in the Barents and Kara seas (as of 2003) required for modeling SNF fission products from some sources on the bottom in the dumpsites and accident zones 1,10. For the first time, the data are given on the background ~(85)Kr concentration in the bottom layer of these seas, as well as the results of long-term (more than 900 days) experiments on assessing the rate of ~(85)Kr and ~(137)Cs escape out of the SNF (pellet fragments of irradiated UO_2). Methods and technique are developed for sampling and extraction of ~(85)Kr and ~(137)Cs (as well as ~3H) on board the vessel and analyses of samples in the shore laboratories. It is shown that ~(85)Kr is the best indicator of the beginning of the failure of fuel elements and UO_2 corrosion. A reliable and inexpensive method is suggested to survey (every 2-3 years) the SNF state on the bottom of the sea with Kr, and, possibly, with ~3H.