Estimated Amount of exp 85 Kr Available for Release from Intact Fuel Rods in the Three Mile Island Unit 2 Nuclear Power Station

摘要

Reactor core dismantling operations planned for the Three Mile Island Unit 2 Power Station could cause rupture of any fuel rods that might have survived the accident in a leak-tight condition. Calculations were performed in an attempt to determine the amount of exp 85 Kr that might be present in the free gaseous form in the plenum and void spaces of such fuel rods. Estimates were made of the number of fuel rods surviving intect, the temperature transient to which they were exposed, the amount of exp 85 Kr orginally produced in the fuel in these rods, and the amounts released from the UO sub 2 matrix to the plenums both before the accident and during the accident (as a result of heatup). Since there is considerable uncertainty in these quantities, particularly the number of surviving fuel rods and the temperature transient they experienced, an analysis was made of the importance of these assumptions. Results of the analysis show that approx.30 Ci of exp 85 Kr could exist in the free state in the plenums of intact rods; however, this quantity might range anywhere from 0 to 100 Ci. 8 figures, 6 tables. (ERA citation 09:000577)