Electrometallurgical Techniques for DOE Spent Fuel Treatment: Spring 1998 Status Report on Argonne National Laboratory's R & D Activity (1998)

AGENDA

Attendance: G. Choppin (chair), M. Apted, P. Baisden, E. Flanigen, C. Hussey, F. Mansfeld, E. McNeese, R. Osteryoung, R. White, J. Williams, D. Raber, C. Murphy, M. Jones.

Unable to attend: B. Kear.

Speakers: Robert Benedict (ANL), Howard Eckert (DOE), Eric Shaber, (INEEL), Charles Forsberg (ORNL), Harold Peacock (SRS), Mal McKibben (SRS), Jerry Christian, (INEEL), Xiangdong Feng (PNL).

Participants: Beverly Cook (DOE), William Hartman (DOE), Dan Funk (DOE), John Kotek (DOE), Tim Long (DOE), Steve Gomberg (DOE), Steve Ludwig (ANL), Greg Bass (ANL), James Laidler (ANL), Harold McFarland (ANL), Yoon Chang (ANL).

Gregory R. Choppin convened the meeting at 8:30 a.m. in NAS 250. Closed meeting discussions included introduction of new committee members and a composition and balance discussion. This was followed by a review of an NBC News video covering operations at ANL-West. The final topic in the closed session was a discussion of committee goals for the meeting.

Robert Benedict, ANL-W, began the open session with an update on the demonstration project at ANL-W. He gave a background on EBR-II spent fuel treatment. A detailed description of the equipment involved in the process included the Mark-IV and Mark-V ERs, the cathode processor, the casting furnace, the glovebox electrorefiners, and the concentric anode cathode design. For the demonstration project, the repeatability demo of four assemblies per month for 3 months was moved back to the September through November period, but he was confident that this demo would be accomplished. The rest of the demonstration project was proceeding on schedule.

Howard Eckert, DOE, spoke on the disposition of DOE SNF. He discussed the current DOE SNF inventory and location, as well as DOE fuel management and disposition strategy. He presented two canister approaches for disposal of SNF, a direct co-disposal approach, and a multicanister overpack approach. Following a presentation of RCRA requirements for SNF disposal, he spoke briefly on the EMT process. He stated that, pending the outcome of the present EBR-II demonstration project, that EMT was the leading candidate for preparation of Fermi-I fuel for disposal.

Eric Shaber, INEEL, began the presentations on alternative technologies to EMT. The high-integrity overpack strategy consisted of placing SNF in high-integrity cans inside standard SNF canisters. These in turn are surrounded by HLW canisters. The final container is a repository waste package. The construction of these canisters was given, as were designs for a high-integrity can.

Charles Forsberg, ORNL, spoke on the topic of glass-material oxidation and dissolution, or GMODS. This technology consists of treating the spent fuel to a first step consisting of oxidation, dehalogenation, and oxide dissolution. The next step is lead oxide reduction, followed by silicate glass formulation to convert the melt to a borosilicate glass as the waste form for disposal.

Harold Peacock, SRS, briefed the committee on melt and dilute technology. The melt and dilute concept involves melting the SNF. The SNF form is dried and sealed in an inert gas container. The off-gas would be treated either by cool and condense and/or trapping, if needed. This waste could then be packaged in either a canister or as solid waste, or it could be acid leached to liquid waste.

Mal McKibben, SRS, summarized the PUREX process and the facilities at Savannah River. PUREX is a counter-current solvent extraction method used to separate and purify U and Pu from SNF and targets.

The SNF is first dissolved and then passed through a series of centrifugal contractors in the first cycle, which removes high activity waste and Pu and U waste. Both the Pu and U waste streams are treated separately through a series of mixer settlers. An overview of the 221-F Canyon at SRS followed. It has been operating since November 1954 and disposes of legacy DOE material. It presently processes 40 MT U per month.

Jerry Christian, INEEL, described the dry chloride volatility processing concept. The process entails chlorination and volatilization of all fuel components at about 1800 K. This is followed by separation of the fission product from the gas stream by condensation and dissolution in a zinc chloride molten salt scrubber at 673 K. The vapors that pass through the scrubber are collected by fractional condensation at 437-275 K. The zinc chloride is then recycled by vacuum distillation at 1000 K.

Xiangdong Feng, PNL, presented information on a direct plasma arc-vitreous ceramic process. The plasma is generated by passing an electric current through a gas, leading to ionization. The plasma torch melts and oxidizes the SNF and sludge at high temperature (>12,000 ºC). The melt is homogenized through the rotating action of the tub and the depression caused by the plasma torch discharging. The melt is discharged from the furnace as the rotation of the tub slows.

After the final presentation, the meeting reverted to a closed session. The presentations were discussed, and writing assignments for the upcoming report were made. A date for the next two committee meetings was made, one for a closed meeting in Washington D.C. on April 27, and a second meeting in Idaho Falls on June 25-26. The first day of this meeting will be open.