Pyrophoricity of Uranium in Reactor Environments

Spent Nuclear Fuel (SNF) surface area estimates for N Reactor fuel in the K-East Basin

“…-Based on the "'Cs release rate and a corrosion rate for oxygenated water cited by G. E. Zima, the estimated true area of the corroding K-East fuel was indicated to be 2.1 x lo6 cm2 (Zima 1960) Based on a visual estimate of the geometric area of corroding fuel in the K-East inventory and applying a roughness factor of 5 resulted in an estimated true area of 2.5 x IO6 cm2.…”

“…According to G. E. Zima, uranium corrosion rates in oxygenated water are 1/20 the rates in hydrogen-saturated liquid water (Zima 1960). The British (Addisson -Private Communication), a value of 1.7 x 1 O 2 mg/cm2 h for uranium metal corrosion in oxygenated water at 25" .…”

Spent nuclear fuel project recommended reaction rate constants for corrosion of N-Reactor fuel

“…Most of Tyfiefd's samples ranged from 0 to 20% swollen, with a few up to 33-43%. Since the preponderance of his samples were not highly swollen, this may have influenced his conclusions The data ofTyfield (1988), Zima (1960), andofBennett (1974), all point to the conclusion that the activation energy is not significantly changed for material swollen 20 % or less. An analysis of Bennett's data however shows that the activation energies for 0%, 56%, and 79% swollen fuel are 16.9, 11.6, and 1.1 kCal/mole, respectively.…”

Spent nuclear fuel project surface area estimates for N-Reactor fuel in the K East basin

“…According to G. E. Zima, uranium corrosion rates in oxygenated water are 1/20 the rates in hydrogen-saturated liquid water (Zima 1960).…”

“…* based on the '37Cs release rate, the Pearce rate equations, and an adjustment for the corrosion rate for oxygenated water cited by Zima (1960), the geometric area of the corroding K East fuel was estimated to be 2.1 x 10' cm2. his surface area will be reduced by whatever fraction of the total corrosion that is occurring anoxically.…”