Disposal of Hanford Site Tank Wastes

Abstract

Hanford Operations andEngineering Contractor forthe U.S.Department of Energy under Contract DE-AC06-87RL10930 Copyright License ByacoDptenceof this attlde, the publishe(end/orrecipientacknowledQesthe U.S. Government'srightto retain • nonexclusive, royalty-freelicense in andto any oopytightoovoringthis paper. M4STER :_ Approved for Public Release ! I)ib"_llfl]UTiON OFTHISDOI_UMI_t_T IS LJNt.IMIT_ ,= LEGALDISCLAIMER Thisreportwas preparedas an accountof worksponsored by an agencyofthe UnitedStatesGovernment.Neitherthe UnitedStatesGovernment nor anyagencythereof,noranyof theiremployees, norany of theircontractors, subcontraclors or theiremployees,makesany warranty, expressor implied, or assumesanylegalliabilityor responsibility forthe accuracy, completeness, or anyIhirdparty'suseor the results of suchuseof anyinformation, apparatus, product,or process disclosed, or representsthat its usewouldnotinfringe privatelyownedrights. Re_erence hereinto any specific commercial product, process, or servicebytradename, trademark, manufacturer, or otherwise, doesnotnecessarily constituteor implyits endorsement, recommendation, or favoringbythe UnitedStates Government or any agency Ihereofor itscontractors or subconlractors. Theviewsand opinionsof authorsexpressedhereindo notnecessarily state or reflectthoseof the UnitedStatesGovernment or any agencythereof. This reporthas beenreproduced fromthe best availablecopy.

Identification and summary characterization of materials potentially requiring vitrification: Background information

“…AIternatives for Long-Term Management of Defense High-Level Radioactive Waste -Hanford Reservation, ERDA 77-44 (September 1977). GEPHART 1995 INEL 1993KLEIN 1992KUPFER 1993LEE 1991LOGHRY 1995LUDWIG 1989 NAS 1995 RODDY 1986SEARS 1990…”

“…Zeolite: An inorganic ion exchange material that has been used to sorb and precipitate radioactive cesium from liquids at West Valley. Precipitate: Radioactive cesium that has been precipitated from liquid waste at the Savannah River Site using potassium tetraphenyl borate.DOE1994a; GEPHART 1995;KUPFER 1993;LEE 1991 ;SEARS 1990…”

Design, Synthesis, and Uptake Performance of ABEC Resins for the Removal of Pertechnetate from Alkaline Radioactive Wastes

“…Among the radionuclides present in the alkaline wastes remaining from the United States' weapons processing activities are the fission products technetium-99 and iodine-129. − These radionuclides present a unique challenge to the remediation of such wastes as they possess long half-lives ( 99 Tc = 2.14 × 10 5 years and 129 I = 1.57 × 10 7 years) and the stable chemical species 99 TcO 4 - and 129 I - (the speciation of these radionuclides in defense wastes has been discussed recently ,, ) are mobile in the terrestrial and aquatic environments. , Vitrification is the widely accepted means of immobilizing radionuclides in the high-level wastes over the geologic lifetime of a repository and is also suitable for decay storage of the short-lived 90 Sr and 137 Cs fission products. ,, The volatility of technetium and iodine compounds in both vitrification and evaporative concentration processing strategies has been studied, ,, and concerns exist regarding the control and isolation of these radionuclides from thermal processing off-gases.…”

“…Alternatives to bulk vitrification of the radioactive wastes include chemical separation 3-5 to partition the short-lived heat-generating 90 Sr and 137 Cs ,,− from the longer-lived transuranium elements. ,,,, Chemical separations would simplify vitrification feed streams, would minimize the amount of vitrified waste requiring geologic deposition, and should have more favorable economics than bulk vitrification . Such a separations-based treatment strategy would permit removal of 99 TcO 4 - and 129 I - , or these nuclides could be selectively removed from the alkaline supernate solutions just prior to bulk vitrification or evaporative concentration, thus eliminating issues regarding their volatilization.…”

Characterization of materials

“…Precipitate: Radioactive cesium that has been precipitated from liquid waste at the Savannah River Site using potassium tetraphenyl borate. DOE 1994a;GEPHART 1995;KUPFER 1993;LEE 1991 ;SEARS 1990…”