[en] An analysis was conducted of tank 241-BY-106 to determine the conditions required for an uneven distribution of heat generation (e.g., a hotspot) that would produce temperatures of concern (considered to be 220 degree C [418 degree F]). Two types of hotspots were investigated. One was 1 meter square, 7.62 cm (3 in.) thick, that was placed on the bottom of the tank two-thirds of the radial distance from the center to the edge of the tank. The other was a 1 meter cube placed in the same location. It was found that the concentrations of heat-producing material required to reach a maximum temperature of 220 degree C (418 degree F) were greater than 160 times that of the material surrounding the hotspot. A transient case was also studied, where a hotspot was formed over 5 years. The 1 meter cube hotspot was used. It was determined that the maximum temperature reached was less than the steady-state analysis under the same conditions. The maximum temperature was reached in 5.5 years. The change in the surface temperature was slow enough that the hotspot could not be detected in less than 3 years. The steady-state analysis showed that a large pattern of thermocouple trees would be required to detect a hotspot by this means. The steady-state analysis showed that a hotspot with temperatures that approached 220 degree C (418 degree F) could probably be detected by surface temperature measurements