DSNF and other waste form degradation abstraction

Abstract

Several hundred distinct types of DSNF may potentially be stored in the MGR (DOE 1999, Appendix D). Therefore, each type cannot be examined viably for its effect on either repository preclosure design basis event (DBE) safety analyses or for postclosure TSPA. To enable analyses of a limited number of potential DSNF types to represent, or bound, the behavior of all DSNF disposed in the repository, the U.S. Department of Energy Office of Civilian Radioactive Waste Management (DOE OCRWM) and the National Spent Nuclear Fuel Program (NSNFP) collaborated to identifl the DSNF groups. These groups are individual categories of spent fuel into one of which all DSNF types would fall for DBE andor TSPA analysis purposes. The description of, and justification for, these spent fuel groupings for repository criticality, DBE, and TSPA analysis purposes are in the NSNFP report, DOE Spent Nuclear Fuel Grouping in Support of Criticaliy, DBE, and TSPA-LA (DOE 2000b). Also, the NSNFP has compiled a report that contains characteristics of the DSNF. groups related to their postclosure performance and suggests models for waste-form dissolution: DOE Spent Nuclear Fuel Information in Support of TSPA-SR (DOE 1999). The DOE SNF groups for total system performance analysis for the Site Recommendation (TSPA-SR) contained in the above documents and described in Sections 6.3.1 through 6.3.1 1 of this document (and a typical type of SNF in the group) follow: Group 1-Naval SNF Group 2-Pu/U alloy (Fermi SNF) Group 3-Pu/U carbide (FFTF-TFA SNF) Group 4-MOX and Pu oxide (FFTF-DFNTDFA SNF) Group 5-TW carbide (Fort St. Vrain SNF)