An Evaluation of the Electrometallurgical Approach for Treatment of Excess Weapons Plutonium (1996)

The disposition of WPu involves, in part, alternative feeds compared to those used in SNF processing. These alternative feeds raise several concerns with respect to electrometallurgical processing, zeolite loading, and waste form performance.

Although ANL has demonstrated an initial program in evaluating zeolite loading, considerable work remains to demonstrate this step in a large-scale, continuous operation with fully radioactive loadings on zeolite columns.

Introduction of WPu in the electrometallurgical process increases significantly the demands on the technology to meet the performance requirement for waste forms relative to the use of the waste forms for ultimate disposal of fission products from SNF processing.

Consequently, greater priority should be given to the development of a strategy and a relevant test protocol to demonstrate acceptability of waste forms. This activity is of the highest importance relative to all other aspects in the development of the electrometallurgical technique for WPu disposition.

The committee concurs with the earlier statements of CISAC and its Reactor Panel on excess weapons plutonium: “The existence of this surplus material constitutes a clear and present danger.”¹ “The timing of disposition options is crucial to minimizing risks. ”² The urgency of moving ahead with disposing of weapons plutonium makes scheduling considerations an important factor in deciding whether or not the electrometallurgical technique is a practicable and timely solution.

The potential advantage of the electrometallurgical technique for disposition of excess plutonium depends on the availability of operational electrometallurgical process equipment. In the absence of operational process equipment, the electrometallurgical approach is not a viable candidate for plutonium disposition. Furthermore, until EBR-II fuel treatment is demonstrated and treatment of additional spent fuel undertaken, it would be imprudent to plan for use of the electrometallurgical technique for disposition of weapons plutonium.

If the demonstration called for in the committee's 1995 report were unsuccessful, no further consideration of the electrometallurgical technique for plutonium disposition would be expected. It is conceivable that the possible failure of the electrometallurgical technique to process DOE spent fuel successfully could result from a feature that would not adversely affect treating WPu. However, such a determination could not be made prior to obtaining the results of the demonstration program.

A decision on the use of the electrometallurgical technique for weapons plutonium disposition cannot be made until the demonstration of this technology shows whether or not this process is viable for treating DOE spent fuels. If a weapons plutonium disposition technology is to be

selected for use with weapons pits before the electrometallurgical technology demonstration program is concluded, this committee recommends that the electrometallurgical technique not be included as a candidate technology.

The potential of the electrometallurgical technique as an adjunct for long-term disposition of non-pit excess plutonium remains a possibility, but the technology is still at too early a stage of development to be evaluated relative to disposition alternatives such as glass or MOX.