Initial retrieval sequence and blending strategy

Abstract

Abstract:This r e p o r t documents t h e i n i t i a l r e t r i e v a l sequence and t h e methodology used t o s e l e c t i t . Waste r e t r i e v a l , storage, pretreatment and v i t r i f i c a t i o n were modeled f o r candidate s i n g l e -s h e l l tank r e t r i e v a l sequences. m e t r i c s ( f o r example, high-level waste glass volume, r e l a t i v e r i s k and schedule).process rates, r e t r i e v a l dates, and blending s t r a t e g y e f f e c t s . The models were based on estimates o f component i n v e n t o r i e s and concentrations, sludge wash f a c t o r s and timing, r e t r i e v a l annex l i m i t a t i o n s , e t c .

Tank waste remediation system operation and utilization plan,vol. I {ampersand} II

“…The work performed during FY 1997 is based upon the results of the retrieval sequence studies performed during FY 1995 (Certa 1995) and FY 1996(Penwell 1996. It is also based upon the results of the FY 1997 LAW and HLW feed staging studies described in this report, and the other major bases and assumptions described in Appendix A of this report.…”

“…Consolidation of all of the pretreated HLW solids in the DST system would allow the "Total Blend (Penwell et al 1996) to be produced, generating the minimum volume of immobilized HLW product.…”

“…During the FY 1995 and FY 1996, the incidental blending, which occurs without any special effort during retrieval and processing, was shown to be very effective at reducing m W glass volumes (Certa 1995 andPenwell 1996). Since it is a form ofundirected blending, it is indiscriminate; there is no precise control over blending.…”

“…None of the SST retrieval sequences run at the baseline conditions (see Appendix A, section 2, 3, 4, 6, 7, 8, and 11) met the September 30, 2018, Tri-Party Agreement interim milestone (M-45-05) for completing retrieval of all SSTs. Previous studies (Certa 1995) (Penwell 1996) showed that if in-tank sludge washing is used, it is the limiting factor because of the time needed to settle the solids after each wash. Therefore, out-of-tank sludge washing was used for this study.…”

“…The FY 1996 study (Penwell 1996) determined the retrieval rates and processing rates needed to meet the 2018 retrieval end date milestone. It showed that unprecedented retrieval rates and transfer complexity associated with retrieval would be required to meet the 2018 retrieval date.…”