Thermal analysis of proposed transport cask for three advanced burner reactor used fuel assemblies

Abstract

Preliminary studies of used fuel generated in the US Department of Energy's Advanced Fuel Cycle Initiative have indicated that current used fuel transport casks may be insufficient for the transportation of said fuel. This work considers transport of three 5-year-cooled oxide advanced burner reactor used fuel assemblies with a burn-up of 160 MWD kg 21 . A transport cask designed to carry these assemblies is proposed. This design employs a 7-cm-thick lead gamma shield and a 20-cm-thick NS-4-FR composite neutron shield. The temperature profile within the cask, from its centre to its exterior surface, is determined by two-dimensional computational fluid dynamics simulations of conduction, convection and radiation within the cask. Simulations are performed for a cask with a smooth external surface and various neutron shield thicknesses. Separate simulations are performed for a cask with a corrugated external surface and a neutron shield thickness that satisfies shielding constraints. Resulting temperature profiles indicate that a threeassembly cask with a smooth external surface will meet fuel cladding temperature requirements but will cause outer surface temperatures to exceed the regulatory limit. A cask with a corrugated external surface will not exceed the limits for both the fuel cladding and outer surface temperatures.

Investigation of Thermal Hydraulic Behavior of Dry Spent Fuel Cask Under Forced Convection

“…The results showed that the peak clad temperature of the fuel bundle was found to be 153°C which is below the temperature limit of 160°C. A transport cask designed to carry used fuel assemblies was proposed [8]. Simulations were investigated for a cask with a smooth external surface and shield thicknesses.…”

“…Domain of calculationsResult analysis And DiscussionThe experimental and theoretical results are classified into two groups according to the model of heat transfer of air cooling outside the steel cylinder to natural or forced convection. Natural convection was discussed and evaluated before by Bullard et al[8]. The Forced convection cooling system results are investigated in the present work.The effect of heaters power, Q variation: The total power is changed to have values of 630, 840, 1050 and 1260 watts.…”

“…Dry Storage Casks are designed to cool and store spent nuclear fuel assemblies for up to 100 years, after they have decayed to an acceptable level of heat generation in spent fuel storage pools. Figure (1) shows the outline of two types of dry concrete casks [8]. The perimeter of the cask often has an annulus which is filled with concrete.…”

Geometrically-Accurate-Three-Dimensional Simulations of a Used Nuclear Fuel Canister Filled With Helium

“…In some models, the fuel and basket are replaced by a smeared region with an Effective Thermal Conductivity (ETC) and an effective porosity [8][9][10][11][12][13][14]. Other models use an accurategeometry computational domain where the fuel rods, gas and the baskets are modeled separately [15][16][17][18][19][20][21][22][23][24][25]. These models are used to predict the peak cladding temperature for a given fuel heat generation rate, and the fuel heat generation rate that causes the clad temperature to reach their allowed limits.…”

“…The geometrically-accurate models overcome the shortcomings of the ETC models but are difficult to construct and require significant computational efforts. Most of the geometrically-accurate models for the simulation of fuel assemblies loaded in a canister in the literature are two dimensional models [15][16][17] or represents only one fuel assembly with an isothermal enclosure [18][19][20][21][22][23][24][25]. Only few works have considered the three dimensional-geometrically-accurate simulations of transfer cask [26,27].…”