Texas to New Mexico to South Carolina to New Mexico is Proposed Pathway for Remaining Surplus Plutonium.
by Don Moniak
December 16, 2022
Plutonium-239 is a man-made radioactive element that is acutely deadly at the scale of milligrams, chronically toxic at the scale of micrograms, decays into more intensely radioactive elements and isotopes, and is useable in nuclear explosives of mass destruction at the scale of kilograms. It has been described as “a physicist’s dream and an engineer’s nightmare.”
The U.S. Department of Energy’s (DOE) Savannah River Site (SRS, formerly Savannah River Plant) produced an estimated 36 tons of the material from the 1950’s to late 1980’s for the nation’s nuclear weapons arsenal. Processing of the resulting unstable, radioactive liquid waste into a relatively stable form has been ongoing since the 1990’s and is expected to continue into the 2040’s. When production ceased in 1990, two tons of plutonium remained in storage, of which approximately 1.5 tons was eventually declared surplus.
Today there is an estimated 11.0 to 11.5 tons of plutonium presently stored at the site, which encompasses parts of Aiken, Barnwell, and Allendale counties in South Carolina. Of this total, 9.5 tons was transferred from other nuclear weapons material and parts production sites—most notably Rocky Flats, Hanford, and Los Alamos—following DOE’s 1997 decision to centralize storage of weapons plutonium.
Two years ago the State of South Carolina reached a $600 million settlement with the federal government over the 9.5 tons of military-grade, surplus plutonium transferred to SRS. Today, DOE’s National Nuclear Security Administriation (NNSA) published a proposal to ship upwards of 27 additional tons of surplus military-grade plutonium to SRS for processing into a waste form through a process called “dilute and dispose”(1).
The proposal was revealed today in a Federal Register notice announcing a sixty-day public comment period for the Draft Environmental Impact Statement for the Surplus Plutonium Disposition Program (SPDP EIS). The impact statement is the latest National Environmental Policy Act (NEPA) document addressing the future of 34 metric tonnes (MT) (2) of plutonium that has been deemed surplus to U.S. defense needs since the early 1990s.
The basic dichotomy for the surplus plutonium begins with:
a. relatively “clean” and pure plutonium within nuclear explosive components known as “pits.” There were presently an estimated 14,000 plutonium pits stored at DOE/NNSA’s Pantex Nuclear Weapons Plant near Amarillo, Texas; of which approximately 10,000 are deemed surplus and 4,000 are “strategic reserve.” Each pit averages There is ~3 kg of plutonium.
b. plutonium not within pits, with highly variable purity levels, most of which is now stored at SRS.
The exact figures for each category are distorted and confused by classification methods, as DOE/NNSA has never revealed precise quantities contained in pit plutonium. However, since the 1990’s the general accepted total of surplus plutonium metal contained in pit form is approximately 25-27 tons.
Since the 1990’s military nuclear weapons complex agencies have conducted multiple environmental impact statements. Efforts to convert 34 metric tonnes of military plutonium into either a waste form or into commercial, mixed-oxide (Pu/MOX) nuclear fuel moved forward, then faltered, and finally failed by 2018, eventually leading to the plutonium settlement between DOE and South Carolina. Less than one ton of the higher purity plutonium constituting the surplus stockpile has been converted to a waste form in twenty-five years, and an estimated quarter-ton was processed in the past year.
The Department of Energy has been shuffling disposition options for surplus, non-pit plutonium since the mid 1990’s. As Ed Lyman reported in his definitive report of DOE/NNSA’s programmatic failures, Surplus Plutonium Disposition: The Failure of MOX and the Promise of Its Alternatives, DOE/NNSA changed its treatment preferences for 13.1 tons of non-pit surplus plutonium eight times in a thirteen year period. The chronic indecision was a contributing factor to the huge cost overruns that helped to end the Pu/MOX fuel fabrication alternative.
After abandoning efforts to convert military plutonium designed for use as nuclear explosives into Pu/MOX fuel, weapons complex agencies moved forward with a disposition method known as “dilute and dispose.” Simply put, “dilute and dispose” involves mixing very small amounts of plutonium (1-3%) with large amounts of a classified mix of materials to create a waste form for permanent disposal.
The only disposal site in the U.S. approved to accept this waste is the Waste Isolation Pilot Plant (WIPP) in Southeastern New Mexico. There remains intense opposition to importing any more plutonium-laden waste into the state than what was originally planned during its design and approval stages in the 1990’s.
In today’s announcement, the NNSA stated its preferred alternative is to pursue the “dilute and dispose strategy for 34 MT of surplus plutonium,” a process involving several steps for plutonium not already at SRS:
- Ship up to 27 tons (3) of plutonium from the Pantex nuclear weapons plant in the Texas Panhandle to the Los Alamos National Laboratory near Sante Fe, New Mexico.
- Disassemble plutonium pits, separate the plutonium from other parts (4) and convert the plutonium metal within to plutonium oxide powder.
- Ship the plutonium oxide powder to Savannah River Site near Aiken and Barnwell, South Carolina for dilution into a waste form.
- Ship the waste to the WIPP near Carlsbad, New Mexico for disposal.
Three alternatives to the preferred alternative are: - Ship plutonium pits to SRS for disassembly and conversion of the plutonium metal to plutonium oxide powder, followed by the dilute and disposal pathway. This option probably ties in with the proposed new plutonium pit fabrication plant at SRS.
- Perform the dilute and disposal pathway at Los Alamos and keep the entire process in New Mexico.
- The No-Action alternative, which would leave the plutonium pits in long term storage and avoid unnecessary shipping, processing, and increased plutonium waste dumping at WIPP.
Not included among the alternatives is the option of demilitarizing plutonium pits by “stuffing” them with inert materials, a proposal first floated in the late 1990’s. Plutonium pits are designed for long-term storage in the nuclear warhead, and can remain stored without expensive shipment and processing.
After years of South Carolina officials declaring that the state could become a permanent plutonium dumping ground, the state is now facing the renewed prospect of SRS processing three times the plutonium presently stored onsite and awaiting dilution and repackaging; as well as fabricating 80 or more new plutonium pits for new nuclear weapon designs at a plutonium pit production plant being designed for production beginning in the early 2030’s.
As reported in Offsite Insight 2022-1, nuclear watchdog Tom Clements informed the SRS Citizen’s Advisory Board about this prospect at their July, 2022, meeting, at which he distinguished between the plutonium already at SRS and the plutonium potentially headed there:
“The number was given as 9.5 MT in the agreement with the state. But there is 11.5 ton onsite because 2.0 tons were already there. But the amount of plutonium to be disposed of is up to 34 tons….We are looking at a tremendous amount of plutonium coming into the site. The CAB will have a very important role in insuring more material is not stranded here.”
Next story: “Plutonium is Not for Amateurs, Part I.”
Residents in the Central Savannah River Area (CSRA) that surrounds the Savannah River Site have the opportunity to comment on the latest proposal either in person or in writing. DOE/NNSA will hold a public meeting upriver from SRS at North Augusta City Hall, 100 Georgia Avenue, from 6 p.m. to 9 p.m. on January 19, 2023. A virtual hearing will be held on January 30, 2023, and comments may be submitted to SPDP-EIS@nnsa.doe.gov.
The Draft EIS, Federal Register Notice, meeting materials, and listing of public comment opportunities is at https://www.energy.gov/nepa/doeeis-0549-surplus-plutonium-disposition-program
and the Draft EIS is at:
https://www.energy.gov/nepa/articles/doeeis-0549-draft-environmental-impact-statement-december-2022
Footnotes
(1) Information regarding the program can be found at:
Presentation material for 3013 Cans and K Area Storage and Processing:
Click to access DOE3013ContainerProgram.pdf
Click to access StorageandDownblend.pdf
A DOE presentation to the National Academy of Sciences in 2018 provides more details:
Click to access McAlhany-SurplusPuDisp_Jun2018.pdf
(2) A metric ton is 1,000 kilograms, equal to 2200 pounds or 1.1 tons.
(3) The DOE/NNSA announcement states that up to 34 MT could be shipped from Pantex, but no documentation exists suggesting there is 34 MT of surplus plutonium within pits, and Pantex presently stores less than one ton of plutonium not within pits. The EIS will, however, analyze the movement of 34 tons from Pantex.
(4) Highly Enriched Uranium within plutonium pits will also be separated and shipped to the Y-12 nuclear weapons material plant near Oak Ridge, Tennessee.
