Comparison of the Amount of Nuclides Released from the Spent Fuel in Contact with and without a Compacted Bentonite Block

Abstract

A spent LWR fuel specimen between Ca-bentonite blocks was leached in a simulated bentonite-saturated granitic water (SBGW) for 165 days and its results were compared with those of a specimen leached without a bentonite block. The amounts of Cs, Sb, Sr, Eu, Am, U and Pu released from a 4.3 mm thickness of a fuel pellet with a 50,400 MWD/MTU burn-up in the SBGW without a bentonite block were 2.2, 0.25, 0.15, 0.02, 0.01, 0.01 and approximately 5 x 10(-4)% of their inventories, respectively. However, the amounts of nuclides released from the specimen between the 1.4 Mg/m(3) bentonite blocks were decreased by three times at least. Moreover, the concentrations of the nuclides in the leachate were very low because most of them were retained in the bentonite blocks.