Process Testing to Support the Conceptual Design of a Plutonium Vitrification Facility
- Savannah River National Laboratory, Aiken, SC (United States)
In the aftermath of the Cold War, the United States Department of Energy (DOE) has identified up to 50 metric tonnes of excess plutonium that needs to be dispositioned. The bulk of the material is slated to be blended with uranium and fabricated into a Mixed Oxide (MOX) fuel for subsequent burning in commercial nuclear reactors. Excess plutonium-containing materials that are not suitable for fabrication into MOX fuel will need to be dispositioned via other means. A lanthanide borosilicate (LaBS) glass was identified as a preferred form for the disposition of the impure plutonium-containing feeds. The LaBS glass formulation uses a lanthanide borosilicate frit rather than the alkali borosilicate frit used to vitrify high level waste. The LaBS glass has been shown to be able to accommodate high quantities of fissile material (greater than 10 wt % elemental plutonium) and tolerate the impurities expected in the plutonium feed streams. A conceptual design effort is now underway at the Savannah River Site (SRS) to design a vitrification facility to immobilize the excess Pu feeds that are not slated for disposition via MOX fuel. The conceptual design phase is planned to complete in FY07. A test program was initiated at the Savannah River National Laboratory (SRNL) to provide input data to the conceptual design effort. A major component of this test effort involves vitrification process testing. A cylindrical induction melter (CIM) was developed for the vitrification of actinide feed streams. Due to the high temperatures required to incorporate high plutonium oxide contents into the glass by dissolution and melting, the melter vessel is constructed out of Pt/Rh alloy and can be operated at temperatures up to 1600 deg. C. Additionally, the melter design is compact to facilitate installation in a glovebox (the size of the conceptual facility melter is approximately 6'' in diameter by 18'' tall). The CIM has proven to be a viable means to process the LaBS glass at processing temperatures of 1400-1500 deg. C. In this paper, the offgas sampling tests conducted in the CIM to capture and analyze the particulate and vapors emitted from lanthanide borosilicate (LaBS) Frit X with HfO{sub 2} as a surrogate for PuO{sub 2} and added impurities are discussed. The tests with impurities added showed that alkali salts such as NaCl and KCl were substantially emitted into the offgas system as the salt particulate, HCl, or Cl{sub 2}. Retention of Na and K in the glass were about 80 and 55%, respectively. Chloride retention was about 35%; chloride remaining in the glass was 0.29-0.37 wt%. Overall, about 58-72% of the impurities added were volatilized. Virtually all of the particulate species were collected on the nominal 0.3 {mu}m filter. The particulate was found to be as small as 0.2 {mu}m and have an approximate median size of 0.5 {mu}m. The particulate salt was also found to stick together by forming bridges between particles. (authors)
- Research Organization:
- WM Symposia, 1628 E. Southern Avenue, Suite 9 - 332, Tempe, AZ 85282 (United States)
- OSTI ID:
- 21294716
- Report Number(s):
- INIS-US-09-WM-07358; TRN: US10V0245040906
- Resource Relation:
- Conference: WM'07: 2007 Waste Management Symposium - Global Accomplishments in Environmental and Radioactive Waste Management: Education and Opportunity for the Next Generation of Waste Management Professionals, Tucson, AZ (United States), 25 Feb - 1 Mar 2007; Other Information: Country of input: France; 3 refs
- Country of Publication:
- United States
- Language:
- English
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