Position paper -- Tank heat loading. Revision 1

摘要

The purpose of this paper is to provide an update to Project W-236A, Multi-function Waste Tank Facility (MWTF), Project File documentation on the selection of the heat removal capability that MWTF Tank Ventilation Systems will be designed to remove. Further scale model mixing tests, as well as greater understanding of the mission of the tanks and the radionuclide heat load, have shown the current heat removal capabilities to be over-designed. Using the latest available information will decrease the amount of conservatism currently in the design. It is important to note that this paper is not for defining the tank mixer pump requirements, but is to be only used for defining and defending the nominal and extreme case heat generation rate that the ventilation system and other heat removal systems will be designed to remove. There are three main heat loads in the tanks of which two can be controlled to a certain extent through operational considerations. These two are mixing pump heat and heat of chemical addition. The third heat source is radionuclide content which can only be controlled by what wastes are pumped to the tank and whether it is diluted prior to pumping. Other heat loads such as transfer pumps were considered to be negligible. In addition, chemical addition is considered a transient situation that is rarely performed and will be treated as such.