Tank 241-C-112 is a Hanford Site FerrocyanideWatch List tank that was most recently sampled in March 1992. Analyses of materials obtained from tank 241-C-112were conducted to support the resolutionof the Ferrocyanide UnreviewedSafety Question (USQ) and to supportHanford Federal Facility i Agreement and Consent OrderI (Tri-PartyAgreement)Milestone M-IO-O0.Analysis of core samples obtained from tank 241-C-112strongly indicates that the fuel concentrationin the tank waste will not supporta propagating exothermicreaction, lt is probable that tank 241-C-112exceeds the 1,000 g-mol inventorycriteria establishedfor the FerrocyanideUSQ; however, extensive energeticanalysis of the waste has determined a maximum exothermic value of -9 cal/g dry waste. This value is substantiallybelow any levels of concern (-75 cal/g) 2. In addition,an investigationof potentialmechanisms to generate concentrationlevels of radionuclideshigh enough to be of concern was performed. No credible mechanismwas postulatedthat could initiatethe formation of such concentrationlevels ] in the tank.Tank 241-C-112waste is a complex material made up primarilyof water and inert salts. The insolublesolids are a mixture of phosphates,sulfates, and