Evolution of repository and waste package designs for Yucca Mountain disposal system for spent nuclear fuel and high-level radioactive waste

Analysis on the characteristics of geologic disposal waste arising from various partitioning and conditioning options

“…In Rechard and Voegele (2014), the disposed package for vitrified glass contains five vitrification canisters and one spent fuel canister in the center. In this paper, we assume the vitrified glass package contains only five vitrification canisters without the central spent fuel canister in order to simplify calculation.…”

“…For computation of mass and volume of vitrified glass, g is assumed as a value of 20% and the density of vitrified glass (q) is taken to be 2700 kg/m 3 : (Wigeland et al, 2004). In Once Through Option, a 5.8 m-long package could hold $9.5 MTHM of PWR spent fuel (Rechard and Voegele, 2014), so the linear loading capacity is 1.64 MTHM/m In three vitrification options, we assume that the waste packages are placed nearly end to end in drift with a gap of 0.1 m, so linear loading capacity could be calculated as follows: Linear thermal power (Q L ) means the thermal output of waste packages disposed in per unit length of drift (unit: kW/m). In all four options, linear thermal power could be calculated as follows:…”

“…Container dimensions in different models(Rechard and Voegele, 2014). flow rate of ventilation, thermal power of packages, and etc.…”

Waste package degradation from thermal and chemical processes in performance assessments for the Yucca Mountain disposal system for spent nuclear fuel and high-level radioactive waste

“…Because of the proposed design change, championed by LLNL [9,33], to double the heat load to dry out the region around the repository for several thousand years (i.e., 28 W/m 2 rather than 14 W/m 2 as proposed in SCP), a major addition in PA-95 was the inclusion of a thermal-hydrologic model ðM TH Þ to explicitly couple heat transfer and fluid flow. The basis of the model was FEHM v1.0 (Finite-Element Heat and Mass) transport code, developed by Los Alamos National Laboratory (LANL) [34].…”

“…A summary of the resulting empirical equations underlying the models is also necessary to define the parameters that were identified in sensitivity analysis as important in explaining the variation in performance measures (cumulative release R prior to 1995 and individual dose D(t), thereafter) [6]. Companion papers provide a historical summary of site selection and regulatory development by NRC and the Environmental Protection Agency (EPA) [7]; hazards and scenarios identified [8]; and repository design and site characterization conducted by the Yucca Mountain Project (YMP) [9,10].…”