Design and construction innovations of the Defense Waste Processing Facility

Construction of the Defense Waste Processing Facility (DWPF) at the Savannah River Site (SRS) is essentially complete. The facility is designed to convert high level radioactive waste, now contained in large steel tanks as aqueous salts and sludge, into borosilicate glass which will solidify in stainless steel canisters. All processing of the radioactive material and operations in a radioactive environment will be done remotely. The stringent requirements dictated by remote operation and new approaches to the glassification process led to the development of a number of first-of-a-kind pieces of equipment, new construction fabrication and erection techniques, and new applications of old techniques. The design features and construction methods used in the vitrification building and its equipment were to accomplish the objective of providing a state-of-the-art vitrification facility. 3 refs., 10 figs

Evidence of Color Coherence Effects in W+jets Events from ppbar Collisions at sqrt(s) = 1.8 TeV

We report the results of a study of color coherence effects in ppbar collisions based on data collected by the D0 detector during the 1994-1995 run of the Fermilab Tevatron Collider, at a center of mass energy sqrt(s) = 1.8 TeV. Initial-to-final state color interference effects are studied by examining particle distribution patterns in events with a W boson and at least one jet. The data are compared to Monte Carlo simulations with different color coherence implementations and to an analytic modified-leading-logarithm perturbative calculation based on the local parton-hadron duality hypothesis.Comment: 13 pages, 6 figures. Submitted to Physics Letters

Vitrification of Rocky Flats ash followed by encapsulation in the Defense Waste Processing Facility

The Department of Energy (DOE) manages approximately 10 to 20 metric tons of plutonium in the form of scrap, residues, oxides, ash, metal, sludge, compounds, etc. Not all of this material is chemically stable or is packaging acceptable for storage. Thus, it constitutes a potential hazard to employees and to the public. This paper describes a relatively simple concept for stabilizing most of this type of plutonium by converting it into encapsulated glass. A full-scale hot demonstration of the concept is proposed, in which Rock Flats ash would be vitrified and sealed in small cans, followed by encapsulation of the cans in Defense Waste Processing Facility canisters with high-level glass

Vitrification of Rocky Flats ash followed by encapsulation in the Defense Waste Processing Facility

Approximately 10 to 20 metric tons of plutonium in the US is in the form of scrap, residues, oxides, ash, metal, sludge, compounds, etc. This paper describes a relatively simple concept of stabilizing most of this type of plutonium by converting it into encapsulated glass. A full-scale hot demonstration of the concept is proposed, in which Rocky Flats ash would be vitrified and sealed in small cans, followed by encapsulation of the cans in Defense Waste Processing Facility (DWPF) canisters with high-level waste glass. The proposal described in this paper offers an integrated national approach for early stabilization and disposition of the nation`s plutonium-bearing residues

Immobilization as a route to surplus fissile materials disposition. Revision 1

The safe management of surplus weapons plutonium is a very important and urgent task with profound environmental, national and international security implications. In the aftermath of the Cold War, Presidential Police Directive 13 and various analysis by renown scientific, technical and international policy organizations have brought about a focused effort within the Department of Energy to identify and implement paths forward for the long term disposition of surplus weapons usable plutonium. The central, overarching goal is to render surplus weapons plutonium as inaccessible and unattractive for reuse in nuclear weapons, as the much larger and growing stock of plutonium contained in civilian spent reactor fuel. One disposition alternative considered for surplus Pu is immobilization, in which plutonium would be emplaced in glass, ceramic or glass-bonded zeolite. This option, along with some of the progress over the last year is discussed

Plutonium-uranium separation in the Purex process using mixtures of hydroxylamine nitrate and ferrous sulfamate

Laboratory studies, followed by plant operation, established that a mixture of hydroxylamine nitrate (HAN) and ferrous sulfamate (FS) is superior to FS used alone as a reductant for plutonium in the Purex first cycle. FS usage has been reduced by about 70% (from 0.12 to 0.04M) compared to the pre-1978 period. This reduced the volume of neutralized waste due to FS by 194 liters/metric ton of uranium (MTU) processed. The new flowsheet also gives lower plutonium losses to waste and at least comparable fission product decontamination. To achieve satisfactory performance at this low concentration of FS, the acidity in the 1B mixer-settler was reduced by using a split-scrub - a low acid scrub in stage one and a higher acid scrub in stage three - to remove acid from the solvent exiting the 1A centrifugal contactor. 8 references, 14 figures, 1 table

Alternative dispositioning methods for HEU spent nuclear fuel at the Savannah River Site

The United States has a strong policy on prevention of the international spread of nuclear weapons. This policy was announced in Presidential Directive PDD-13 and summarized in a White House press release September 27, 1993. Two cornerstones of this policy are: seek to eliminate where possible the accumulation of stockpiles of highly- enriched uranium or plutonium; propose{hor_ellipsis}prohibiting the production of highly-enriched uranium (HEU) or plutonium for nuclear explosives purposes or outside international safeguards. The Department of Energy is currently struggling to devise techniques that safely and efficiently dispose of spent nuclear fuel (SNF) while satisfying national non-proliferation policies. SRS plans and proposals for disposing of their SNF are safe and cost effective, and fully satisfy non-proliferation objectives