Advanced technologies for decontamination and conversion of scrap metals

Recycle of radioactive scrap metals (RSM) from decommissioning of DOE uranium enrichment and nuclear weapons manufacturing facilities is mandatory to recapture the value of these metals and avoid the high cost of disposal by burial. The scrap metals conversion project detailed below focuses on the contaminated nickel associated with the gaseous diffusion plants. Stainless steel can be produced in MSC's vacuum induction melting process (VIM) to the S30400 specification using nickel as an alloy constituent. Further the case alloy can be rolled in MSC's rolling mill to the mechanical property specification for S30400 demonstrating the capability to manufacture the contaminated nickel into valuable end products at a facility licensed to handle radioactive materials. Bulk removal of Technetium from scrap nickel is theoretically possible in a reasonable length of time with the high calcium fluoride flux, however the need for the high temperature creates a practical problem due to flux volatility. Bulk decontamination is possible and perhaps more desirable if nickel is alloyed with copper to lower the melting point of the alloy allowing the use of the high calcium fluoride flux. Slag decontamination processes have been suggested which have been proven technically viable at the Colorado School of Mines