Organic Tank Safety Project: Equilibrium moisture determination task fiscal year 1997. Annual progress report

Twenty waste storage tanks at the U.S. Department of Energy`s Hanford Site are included in the Organic Tank Watch List. The water content in the wastes plays a significant role in preventing propagating or sustainable chemical reactions, and the fuel and energetics independent safety criterion has been determined to be 20 wt % water. To ensure that the organic-bearing wastes continue to be stored safely, Duke Engineering and Services Hanford commissioned the Pacific Northwest National Laboratory to investigate the effect of water partial pressure (P{sub H2O}) on the water content of organic-bearing or representative wastes. If necessary, the P{sub H2O} could be managed to maintain the water content at an acceptable level or adjust the water content back to an acceptable level. During fiscal year 1997, the effect of P{sub H2O} was tested to determine how organic-bearing wastes will respond if exposed to environmental Hanford water partial pressures or other potential water partial pressures. The samples tested were obtained from Organic Watch List Tanks, tanks that D.A. Reynolds of Lockheed Martin Hanford suspects may contain wastes having significant organic content, or wastes characteristic of organic-bearing wastes. Temperatures at or near maximum tank waste surface temperatures were used in the tests. At 26{degrees}C, the lowest temperature used, the water partial pressures used in the tests ranged from 2 to 22 torr. At 41{degrees}C, the highest temperature used, the water partial pressures used ran ed from 3.5 to 48 torr