Behavior of carbon-14 in waste packages for spent fuel in a tuff repository

TSPA 1991: An initial total-system performance assessment for Yucca Mountain; Yucca Mountain Site Characterization Project

“…The "quick-release" part of the _4C inventory can be released without water being present (Van Konynenburg et al, 1985, and the fue' matrix alteration process that liberates the 14C in the UO2 matrix could be able to proceed without water being present (but perhaps at a lower rate; little is known about the effect of water on the matrix-alteration rate). Regardless of whether water is important to _4C mobilization, it certainly is important to the processes that lead to container failure.…”

“…The quick-release fraction of the t4C inventory comes from an oxidation layer on the surface of the fuel-rod cladding (Van Konynenburg et al, 1985. The 14C comes off in gaseous form and is available for release as soon as the waste container has .…”

Repository seals requirement study

“…viii May 1997 The results showed that anticipated water flows through shafts were of the order of 1 to 170 m3 per year, and would not likely exceed the flow capacity of backfilled shafts. The anticipated flow rates for the ramps was from 400 to 2,400 m3 per year and reflects infiltration through dominantly vertical fractures.…”

“…For 14C, 0.3 percent of the radionuclide inventory in a stored canister of spent fuel is released as a gas (Section 3.6) (Van Koynenburg et al 1984). For l291[, the radionuclide inventory in spent fuel may be concentrated in the pellet-cladding gap and/or on the grain boundaries of the fuel (Oversby and McCright 1985).…”

Repository seals requirements study

“…For 14C, 0.3 percent of the radionuclide inventory in a stored canister of spent fuel is released as a gas (Section 3.6) (Van Koynenburg et al 1984). For 12()1, the radionuclide inventory in spent fuel may be concentrated in the pellet-cladding gap and/or on the grain boundaries of the fuel (Oversby and McCright 1985).…”