Title:
High Level Nuclear Waste at the Savannah River Site— Past, Present, and Future
High Level Nuclear Waste at the Savannah River Site— Past, Present, and Future
No Thumbnail Available
Author(s)
Hobbs, David T.
Advisor(s)
Editor(s)
Collections
Supplementary to
Permanent Link
Abstract
The Savannah River Site (SRS) operated five heavy water nuclear reactors and two
separation canyons for the production of nuclear materials for defense, special isotope
production and space programs. These operations produced more than 100 million gallons of
high-level nuclear waste (HLW), which has been stored in underground carbon steel tanks.
The highly alkaline HLW consists of three forms; precipitated metal hydroxides and hydrous
metal oxides referred to as sludge, supernatant liquids or supernate, and crystalline sodium
salts referred to as saltcake that are formed upon evaporation and cooling of waste
supernates. The current inventory of HLW at SRS is about 38 million gallons. Disposition of
the HLW seeks to immobilize more than 99% of the radioactivity in a highly durable
borosilicate glass wasteform. Concentrated liquid and saltcake are retrieved and pretreated
to remove cesium, strontium, and alpha-emitting radionuclides. The separated radioactive
components transfer into the Defense Waste Processing Facility (DWPF) for vitrification
along with the sludge fraction of the HLW. The decontaminated liquid waste transfers into
the Saltstone Production Facility (SPF) for incorporation into a cement wasteform for onsite
disposal as a low-level waste. The DWPF began radioactive service in 1996 and to date has
produced more than 3250 glass canisters. The SPF began radioactive operations in 1990 and
has immobilized more than XX million gallons of decontaminated waste liquids. Two
pilot-scale pretreatment facilities, the Actinide Removal Process (ARP) and the Modular
Caustic Side Solvent Extraction Unit (MCU) began radioactive operations at SRS in 2008. The
ARP facility uses an inorganic ion exchanger, monosodium titanate (MST), to remove 90Sr
and alpha-emitting radionuclides (principally 238Pu, 239Pu, 240Pu and 237Np). Following
treatment with MST, the waste passes into the MCU for removal of radio-cesium using a calixarene extractant. The Salt Waste Processing Facility (SWPF), currently under
construction will use these same processes to treat the HLW at a throughput of about 7
million gallons per year beginning in 2014. A new initiative, referred to as the Small Column
Ion Exchange (SCIX) process is under development to accelerate pretreatment of salt
wastes at SRS. The SCIX operation uses an inorganic ion-exchanger, crystalline silicotitanate
(CST) for the separation of cesium and strontium from waste solutions. This separation
technology will feature two small ion-exchange columns located within a high-level waste
tank.
Sponsor
Date Issued
2012-03-07
Extent
59:37 minutes
Resource Type
Moving Image
Resource Subtype
Lecture