Establish parameters for a metal waste form melting furnace; and
Demonstrate multistage pyrocontactor for removal of TRUs from electrolyte salt.
If the DOE decides to develop the electrometallurgical process as a possible treatment for N-reactor fuel from Hanford, the following steps from the ANL proposal through spring of 1996 will also be required:
Complete dissolution tests with unirradiated N-reactor fuel;
Test anode assembly concept for high throughput of N-reactor fuel;
Obtain 20 to 30 N-reactor fuel assemblies at ANL-West;
Develop process chemistry for oxide reduction and lithium recycle;
Develop accurate mass-balance statistics; and
Install pump/filtration equipment in the Fuel Conditioning Facility.
Because there are no current plans to apply the electrometallurgical process to Hanford's K-basin sludges, oxide fuels other than oxidized N-reactor assemblies, or waste forms, the committee believes that the portions of the ANL proposal relating to these important problems are premature.
Underlying all these processing activities is the clear but infrequently articulated need to provide absolute assurance that a critical mass cannot be accumulated during any process step. The size of specific hardware and equipment items, process flow sheets, and system configuration together with storage arrangements will be important to providing this assurance.
The committee believes that a geologic repository will not be ready to receive material for many years, and interim storage of at least 20 years will be unavoidable for end products and waste streams from any DOE fuel treatment process. If such processes were to yield separated uranium and plutonium, the storage problems would be significantly increased, as would the need to safeguard these separated materials from theft and diversion. Above all, product streams from this development program must be of a nature that their later treatment for ultimate disposal after interim storage is not precluded.
The progress of the electrometallurgical treatment program needs to be monitored by the DOE and assessed periodically to determine its continued technical viability and schedule and budget effects. As stated above, this involves oversight primarily of the EBR-II spent fuel treatment program and secondarily of the supporting ANL proposal items noted above.
The committee noted the following apparent advantages and disadvantages of the electrometallurgical technique as a candidate technology for treatment of DOE SNF.