Calculation of used nuclear fuel dissolution rates under anticipated Canadian waste vault conditions

Dissolution rates of UO2 fuel are determined as a function of alpha and gamma dose rates. These room-temperature rates are used to calculate the dissolution rates of used fuel at 100 degrees C. Also, the alpha, beta and gamma dose rates in water in contact with the reference used fuel are calculated as a function of cooling time. These results are used to calculate used CANDU fuel dissolution rates as a function of time since emplacement in a defective copper container for the Canadian Nuclear Fuel Waste Management Program. It is shown that beta radiolysis of water is the main cause of oxidation of used CANDU fuel in a failed container and that the use of a corrosion model is required for similar to 1000 a of emplacement in the waste vault. The results obtained here can be adopted to calculate used nuclear fuel dissolution rates for other waste management programs. (C) 1997 Elsevier Science B.V.