by Don Moniak
April 10, 2023

The U.S. Department of Energy’s (DOE) Savannah River Site (SRS) and environmental protection agencies charged with protecting public health and our environment from the radioactive, toxic, Cold War SRS, recently collaborated on a news release from Superfund site owner DOE-SRS that understated the risks of SRS radioactive wastes, and overstated the significance of an updated radwaste cleanup agreement that could ultimately allow more radioactive waste disposal at SRS. The regulatory agencies charged with protecting public health and our environment from the hazards at SRS allowed a Superfund site owner, in this case the federal government, to lead the public communications effort.

In August of 2020, the State of South Carolina reached a settlement with the federal government to remove 9.5 tons of stabilized, surplus plutonium stored at the Department of Energy’s (DOE) Savannah River Site (SRS) by 2037.  The stored plutonium is not considered a nuclear waste and is stored above ground.

This past December, two years after the plutonium settlement, the South Carolina Department of Health and Environmental Control (DHEC) and the US Environmental Protection Agency modified an agreement with DOE-SRS on the management of thirty-five million gallons of highly radioactive, liquid waste. Unlike the plutonium, this “high-level” waste is in an unstable form, and is stored in forty three underground storage tanks; some of which are “either fully or partially submerged in the ground water,” according to a 2014 Nuclear Regulatory Commission (NRC) assessment.

Unlike the SRS plutonium legal settlement that defines how much material must leave the state by 2037, either pure or in a diluted waste form, the radwaste agreement is vague enough to provide loopholes for the federal government to dispose of more radwaste at SRS in massive, modern waste tanks.

The Collaborative News Release

On March 28th, three months after signing of the modified agreement, the Department of Energy’s (DOE) Savannah River Site (SRS) operations office issued a news release titled SRS, Regulators Reach Agreement for Liquid Waste Cleanup Milestones. The story pertained to the future management of the 35 million gallons of unstable mix of highly radioactive waste and less reactive and radioactive waste remaining within the radwaste tanks. This radwaste setting at SRS has long been considered the greatest environmental, safety, and health threat in South Carolina; and one of the greatest in the nation—dwarfing the formidable plutonium storage concerns.

The news release was a public relations work of art; typical DOE fare that omitted any reference to the inherent dangers of the radwaste while presenting an insignificant update to an old agreement as a great milestone. What is most unique about the delayed news is that DOE officials admit it was a collaboration (1) between DOE, DHEC, and the EPA.

In the release, DOE-SRS public relations staff quoted DHEC official Henry Porter stating:

“Collaborating with the federal government to agree upon these milestones, values, and goals is critical in achieving the site’s waste cleanup mission and protecting the community and environment beyond the barricades.”

EPA official Randall Chaffins chose to state the obvious prior to complimenting DOE’s relationship with its contractors:

“Safely remediating the radioactive liquid waste and removing the tanks from service at the Savannah River Site protects human health and the environment. EPA is appreciative of the mutually beneficial partnership with DOE and its contractors.”

Neither DHEC nor the EPA have issued independent statements. Questions sent to Mr. Porter and DHEC media contacts on April 3rd were diverted to DHEC’s “constituent services division,” and remain unanswered. (2)

The collaborative news release describes the radioactive waste tanks as “one of the largest environmental risks in South Carolina,” but failed to identify why the radwaste complex qualified for this designation.

The inherent hazards within the waste tanks, and the risks of fires, explosions and leaks are excluded from the narrative. The words cesium, strontium, plutonium, mercury, and hydrogen, to name a few of the hazardous radwaste elements, are absent.

The kinder, gentler term “Liquid Waste” is used in lieu of “radioactive liquid waste” in all but a few instances.” Reduction of “curies” is presented as the primary goal, but the curie inventory is omitted and no context is provided.

“High level radioactive waste” is reduced to “high level waste tank” in the first two paragraphs. To the uninformed, the concept sounds like a physical and geographic description, not an indication of danger.

Community-Free Collaboration

Surrounding communities most at risk from accidents, and most economically affected by the stigma of nearby unstable radwaste, were absent from the negotiations. At the January meeting of the SRS Citizens Advisory Board in downtown Aiken, DHEC and the EPA devoted less than two minutes briefing the Board on the update during the general updates portion of the meeting (3). No public forums are planned by the agencies charged with protecting communities from harm.

Meanwhile, the collaborative negotiations did involve the “liquid waste contractor at SRS, Savannah River Mission Completion (SRMC), (who) assisted with FFA milestone negotiations.” The contracting consortium which stands to profit from any delays in radwaste risk reduction was at the table, but communities who bear the most risk were absent.

The Agreement and The Amendment

The agreement amendment, which was more of a minor, even trivial, adjustment to the larger, forty-year old Federal Facilities Agreement between the agencies and the responsible Superfund site party, was signed by the three parties December 22, 2022. The amendment (4) is shorter than the news release, and is merely an agreement to pursue common “goals and values,” that leaves DOE’s radioactive waste processing and tank closure schedules, as defined in its internal 2019 plan, unchanged. A slightly updated tank closure schedule that mirrors DOE plans is also included.

Most notable among the common “goals and values,” are two “values” for which “vague” is an understatement:

“3. Maximize the amount of curies (especially long-lived radionuclides) vitrified and ready for ultimate disposal out of state; and
4. Limit disposal of curies onsite at SRS so that residual radioactivity is as low as reasonably achievable.”

The agreement amendment contains no firm, quantitative targets, and no defined framework for measuring “as low as reasonably achievable” compliance. The loophole for dumping more “low level” radwaste into six or seven, new, thirty-million gallon Saltstone Disposal Units at SRS is obvious.

The agreement corresponds to DOE’s own plan for closures and completion of the risk reduction effort (5) It does not accelerate the pace of tank closures (6) The tank radwaste produced over a 35-year period will still take at least 40 years to remediate to a safer form, and no legal path for removing any waste from SRS to a long-term disposal site is in sight. The amended agreement was an agreement to take as long as, if not longer, to finish waste processing than in previous agreements.

Hydrogen in RadWaste

One of the omissions of fact in the news release was the hydrogen hazard. While DOE-SRS continuously work towards a greater understanding of hydrogen gas generation which is a key constant limiting radwaste risk reduction progress, DHEC and the EPA do not appear to share the same level of concern.

Coincidentally, one week after the agreement was signed, SRS workers discovered a failed part in its defense-in-depth safety system to prevent hydrogen explosions in the radioactive waste storage tanks. A January 11, 2023 report describes the important, though not uncommon, or unexpected discovery:

“On December 29, 2022, during startup of the Tank 25 purge exhaust fan, Operations noticed steam vapors coming from purge stack. When the purge fan was secured with steam in service, steam vapors were visible. Subsequent inspection of Tank 25 revealed liquid under the purge cabinet. The purge fan was secured. The Tank 25 purge reheater has a functional class of Safety Class and is a credited control to prevent a waste tank explosion.”

Purge reheater failures were reported several other times since 2013, but in those reports there was no mention of its Safety Class role in preventing waste tank explosions.

The DOE-DHEC-EPA agreement contains a single sentence about hydrogen gas generation. In the 2018 revision, a requirement was added about monitoring and reporting of “new nuclear safety requirements regarding hydrogen generation rates within the tank systems.” No updates to this requirement were made in the December 2022 amendment.

“Liquid Waste”

“Liquid Waste” is the kinder, gentler term used to describe the intensely radioactive mixture of precipitated salts referred to as “saltcake”, lighter salt solutions referred to as “supernates”, and heavier, but more mobile, fluids referred to as “sludge” that is presently stored in dozens of Cold War era, gallon waste tanks at Savannah River Site (SRS) ranging in size from ~0.75 to 1.3 million gallons.

The waste is primarily a product of Cold War nuclear weapons materials production, a complex mix of nuclear fission products generated during plutonium production, dissolved nuclear fuel metal cladding (generally aluminum) and the acids, solvents, mercury, and other materials used during the plutonium purification process.

According to the Institute for Energy and Environmental Research’s (IEER) Nuclear Dumps by the Riverside, the “ main radionuclides remaining in the tanks are strontium-90, cesium-137, technetium-99, and cobalt-60, but the residual waste also includes selenium-79, carbon-14, iodine-129, plutonium-238, -239, -240, -241 and -242, neptunium-237, americium-241, and curium-244 and -245.”

Since the mid 1990’s, various SRS contractors have worked towards converting unstable, liquid radioactive tank waste into more stable, solid forms; and “closing” tanks by encasing the residual, most difficult to remove waste in grout.

There is presently 34.2 million gallons of this unstable radioactive waste remaining in 43 waste tanks, with a total reported radioactivity in March of 2022 of 220 million curies, half the total of that reported in 2002. Revision 21 of the SRS Liquid Waste System Plan reported 61 million curies encased in glass, 0.5 million in Saltstone grout, and a ~240 million curie reduction due to natural radioactive decay.

Considerable progress has been made with SRS radwaste risk reduction, especially in comparison to the decades of failed start-up efforts at DOE’s Hanford Plant in Washington State, but at rates well below original forecasts.

The workforce for this cumulative cleanup task constitutes one of the larger labor pools in Aiken County, with the primary contractor employing ~ 2500 people.

Risks of Fires and Explosions in Radioactive Waste Tanks

While leaks from the tanks draw the most attention, the greatest hazard involves the risk of explosions. The infamous Kyshtym chemical explosion in 1957 at the Mayak “Production Association” plutonium recovery and processing site was the earliest warning of the worst consequences from mismanaging plutonium recovery waste.

The explosion caused the release of ~twenty million curies of radioactivity, of which ~two million curies spread outside of the Mayak radiochemical production complex. Ultimately 9,000 square miles were contaminated, about 10,000 people were evacuated, and the adverse and tragic regional human health effects are still being studied and debated seven decades later.

A 2017 article in the Journal of Radiological Protection described the disaster as follows:

“Starting in the earliest period of Mayak PA activities, large amounts of liquid high-level radioactive waste from the radiochemical facility were placed into long-term controlled storage in metal tanks installed in concrete vaults. Each full tank contained 70–80 tons of radioactive wastes, mainly in the form of nitrate compounds. The tanks were water-cooled and equipped with temperature and liquid-level measurement devices. In September 1957, as a result of a failure of the temperature-control system of tank #14, cooling-water delivery became insufficient and radioactive decay caused an increase in temperature followed by complete evaporation of the water, and the nitrate salt deposits were heated to 330 °C–350 °C. The thermal explosion of tank #14 occurred on 29 September 1957 at 4:20 pm local time. At the time of the explosion the activity of the wastes contained in the tank was about 740 PBq [5, 6]. About 90% of the total activity settled in the immediate vicinity of the explosion site (within distances less than 5 km), primarily in the form of coarse particles. The explosion gave rise to a radioactive plume which dispersed into the atmosphere.”

A nontechnical description of incident is that the waste “overheated and exploded, belching up a 160-ton cement cap buried twenty-four feet underground and tossing it in the air. A column of radioactive dust and smoke rocketed skyward for a half mile, which sent down a sooty fallout. The blast issued into the earth’s atmosphere 20 million curies.”

The U.S. Atomic Energy Commission, its successor agencies DOE and the NRC, and their contractors, have long recognized the hazards and worked to mitigate them, even while routinely downplaying the hazards to the public.

A 1976 Analysis of Hydrogen Explosion Hazards from Savannah River Laboratory researcher J.B. Porter reported that “small concentrations of gaseous hydrogen are safe in the absence of air; however, any air leaks in the process equipment could cause an explosion-fire hazard.”

The likelihood of a hydrogen explosion today in the waste tanks holding is considered very low, due to the intense and expensive levels of safety mitigating the hazard. But it is real enough that hydrogen generation is a primary limiting factor inhibiting the progress of processing the unstable radwaste to more stable forms; and efforts to reduce hydrogen generation are necessary to meet radwaste risk reduction goals.

Hydrogen is generated in high level radwaste tanks from radiolysis, chemical heat decomposition, and decomposition of some organic materials. Stirring of the sludge layer and the “homogeneity” of sludge batches necessary for processing at the SRS vitrification plant creates added hydrogen generation concerns.

In a presentation and paper titled “Structural Effects of Postulated Hydrogen Explosions in Process Piping and Vessels,” SRS researcher Charles Keilers described the risks as follows:

“Liquid HLW generates hydrogen from radiolytic and thermolytic decomposition; the hydrogen poses an explosion hazard. Unless purged, it may build up to flammable levels – 4 vol% in air or higher. Combustion at low concentrations results in a slow, low-intensity pressure transient – a low-level deflagration – that could injure unprotected personnel but is not structurally damaging. However, at about 12 vol% in constricted geometries, the flame front can accelerate to hundreds of meters-per-second and be capable of deflagration-to-detonation transition (DDT).

Hydrogen monitoring and control is a constant at the waste tank complex. Tanks are categorized according to the rate of hydrogen generation; such as “very slow” and “slow generation” tanks. Hydrogen is purged and ventilated in “slow” tanks and failed hydrogen monitors merit incident reports from the contractor to DOE managers; but forced ventilation is not required in “very slow” generation tanks.

While the federal government and its contractors are circumspect during public discourse in risk assessments of fires and/or explosions that could scatter radioactive debris across the countryside, the measures undertaken provide enough evidence that the possibility is real.

In a 2009 emergency planning document, Savannah River National Laboratory (SRNL) researchers wrote that:

“Potential source terms are sufficiently large to require that SRS maintain an ingestion exposure emergency planning zone (IPZ) for emergency response.”

The radius for this emergency planning zone is 50 miles(below)

Even in the absence of measurable human suffering, the stigma of radioactive contamination would negatively impact property values across the region and cripple local agricultural markets, at least in the short-term. The only entity willing to underwrite insurance against such an accident is the federal government, which is mandated by the notorious, sixty-five year old Price-Anderson Act to underwrite liability for any major nuclear accident.

Even in the absence of an accidental off-site release of radioactive materials, a hydrogen fire or explosion in piping or processing vessels could injure workers, disrupt waste processing for months or even years, and cost tens of millions of dollars to repair.

The 2014 accident at the Waste Isolation Plant (WIPP) in Southeast New Mexico, the nation’s dumping ground for transuranic radwaste heavily contaminated with plutonium and/or other actinide isotopes, is an instructive example.

Nine years ago a fire caused a container filled with transuranic waste to rupture. The subsequent radiological release contaminated twenty two workers and prompted a three year shutdown of the WIPP and DOE’s national efforts to ship waste there. It was a billion dollar accident that permanently sullied the reputation of WIPP.

According to a recent research paper in the Journal, Process Safety and Environmental Protection, the root cause of the accident escaped detection for eight years, but was postulated to have involved the use of an organic cat litter brand that was mistaken for an inorganic material. The paper has a title that, if not serious, would suggest an imagination run amock: Thermal runaway of nitric acid-soaked kitty litter in transuranic waste.

Prevention of serious accidents at SRS is the responsibility of the Department of Energy and its contractors. South Carolina’s Department of Health and Environmental Control and the EPA are mandated to provide backup and assurances for SRS radioactive waste operations. If the agencies are collaborating with a polluter and responsible party on a feel-good public relations campaign, how necessary are they in the process? DHEC in particular is certainly not living up to former Governor Nicki Haley’s statement in 2016 that “We will not back down: South Carolina will not be a permanent dumping ground for nuclear waste.” 

FOOTNOTES:

(1) The DOE-SRS answer to the question of public relations collaboration:

(2) The following was sent to DHEC on April 3rd:

“Mr. Porter, 

The Department of Energy’s Savannah River Site issued a news release regarding the revised Federal Facilities Agreement between DOE, DHEC, and EPA. The article states you signed the agreement, and attributes this statement to you: 

“’The South Carolina Department of Health and Environmental Control considers the high-level waste at the Savannah River Site one of the largest environmental risks in the state,’ Porter said. ‘Collaborating with the federal government to agree upon these milestones, values, and goals is critical in achieving the site’s waste cleanup mission and protecting the community and environment beyond the barricades.'” 

Could you explain: 

1. Why are the waste tanks “one of the largest environmental risks in the state?” DHEC’s own webpage also fails to explain the risks; it only identifies the existence of the hazard. What are risk “beyond the barricades?” 

2. What are the other largest environmental risks in the state? 

3.  What increased risk is there for non-DOE employees and contractors working within the “barricades,” , or traveling through the site?” For example, the U.S. Forest Service conducts timber sales that result in timber harvesting crews being on-site year round. Hwy 125 is a major evacuation route that passes through SRS. CSX Railroad operates a major rail line through the site. 

4. Where is the DHEC news release? 

I have not located any news releases at the DHEC website regarding this latest development. Does DHEC routinely allow the polluter to write the narrative about the risks they create and are charged with controlling? Is this part of what “collaboration with the Federal Government” also means: that the polluters from the Federal Government, and its contractors, define what is and is not important for our communities and our environment? 

5. Why was there no community representatives present during these negotiations, while the federal government’s contractor was involved? How is it that those who bear the greatest risks from delay of radioactive waste risk reduction are absent, but the entity that stands to profit from any delays is present? 

The following questions were also posed to the media division of DHEC:

“Could someone please explain why DHEC did not issue its own news release, thus allowing the polluter DOE, to define the terms of the agreement? 

Was there an agreement between DHEC, DOE, and EPA to allow DOE to take the lead on the public information front of this issue? 

Why is the agency charged with protecting South Carolina communities and resources allowing the federal government to write the news, but declining to do so itself? 

(3) The discussion of the updated FFA at the SRS CAB meeting included the following comments, taken from the You Tube video of the meeting and edited for clarity:

At the 41:00 minute mark of the SRS Citizen Advisory Board meeting on January 23, 2023, DOE-SRS Site Manager Michael Budney addressed the updated FFA for one minute during his statement:

“We all signed the 2022 high level waste tank Milestones agreement so this sets the plan for 16 old style high-level waste tanks.  The actual milestones for cleaning those tanks. And we have a plan to complete all 51 tanks within 14 years by the end of 2037.  You know last year that the word was finished in 15, um now it’s finished in 14. We’ve got to keep updating that every year we don’t want to keep saying finish in 15 because that’ll just extend the program so 2037 is a date to get it all done. And that Milestone agreement has been Incorporated in appendix L of our federal facility agreement which is available at http://www.srs.gov and it’ll appear in the appendix for fiscal year 23.”

In other words, there was no change to the schedule. The agreement had to be updated to read “ fourteen years” instead of “fifteen years” because a year had passed, not because the overall schedule had been changed. 

After addressing the updated amendment, Mr. Budney added, in relation to the upcoming processing schedule, that at the vitrification facility (DWPF): 

“We are undergoing the final implementation of the glycolic acid chemical flow sheet which is known enables us to increase the rate which we put material through there because it reduces the rate at which hydrogens produce in those facilities so we’re able to step up the rate to meet the potential processing rates at DWPF.”

Also at that meeting, DHEC official Susan Fulmer touched upon the agreement for less than thirty seconds, at the 1:06 mark:

“The liquid waste tank Milestones that were negotiated and that agreement was signed in December, that was the result of many many many months of work by all three parties. It was a very good discussion back and forth trying to really understand the liquid waste program and so we really appreciated the efforts that DOE and their contractor put forward to helping us understand and for the three parties to be able to arrive at the new tank Milestone schedule so that was a a good way to end the year wrapping those negotiations up.” 

The FFA was not on the list of the SRS-CAB’s “topics of consideration” for future meetings.

The SRS-CAB does not engage with the public, issues no independent reports for public consumption, allows no questions during its meetings, and only allows 30 minutes for public comments towards the end of each day of its meetings. The Board routinely meets far from the site boundaries, and has not met in Barnwell or Allendale Counties for more than twenty years.

(4) The 2022 High Level Radioactive Waste amended agreement to the Federal Facilities Agreement is one and half pages long, with two attachments, and is on pages 310 to 314.

(5) The end-date goal for completion of the conversion of unstable radioactive waste to more stable, manageable, solid forms, and closure of waste tanks is still not expected until 2037. The 2037 goal requires waste processing at steady rates exceeding the past two decades of liquid-to-solid waste processing production; as this table in the 2019 system plan illustrates:

(6) In 2007, DOE committed to closing 22 waste tanks by 2022. According to a presentation at the March 2022 SRS Citizens Advisory Board meeting, only eight of the original fifty-one tanks have been closed.

In the 2019 System Plan, tank closures were scheduled by 2035. All bulk waste removal was to be complete in older style tanks by 2031; and tanks were to be removed from service by 2035. The new agreement appears to provide two more years to finish the job. The FFA appears to follow the DOE plan, and not set the pace for the DOE plan.