On Monday this week, I interviewed for a consulting position to work as a geochemical modeler on the Waste Isolation Pilot Project, called the WIPP site, located in Carlsbad, New Mexico. Although I may still be in contention for the remote-worker position, I would rather share some of the incredible publicly-available news I learned so far. I will briefly share a few interview reflections, some site history, including an underground fire, release of radionuclides and whistleblower lawsuit, and current events leading up to decisions to continue allowing disposal of nuclear waste.
Making nuclear weapons and laboratory experiments generate radioactive waste materials contaminated mostly with highly toxic plutonium and americium. The nuclear weapons complex, including at national laboratories, generated nuclear waste from 22 sites across the country; significant quantities of waste were created during and after the Manhattan Project of the 1940’s. I’ve worked at or toured many of these locations including Los Alamos, NM, Hanford, WA, Oak Ridge, TN and the Nevada Test Site.
The WIPP site began construction in 1981 and completed to receive radioactive waste shipments in 1999. Drums of waste were sent by truck shipments to WIPP then disposed in salt mines. But of course Murphy’s Law ("Anything that can go wrong will go wrong") prevailed; two tragic events occurred in February 2014: an underground salt haul truck caught on fire; then a week later in a different part of the repository, on Valentine’s Day 2014, a drum breech vented radioactivity underground and escaped to above ground. As reported by NPR, an investigation tracked the drum’s origin back to Los Alamos National Labs that incorrectly switched from an inorganic to organic type of absorbent cat litter. The official DOE investigation report states that trace amounts of radioactivity were also vented to the surface onsite and offsite. HEPA air filters were not designed to handle the unplanned release and now DOE is spending about $500 million on a new ventilation system to be completed by next year. WIPP shut down for three years and restarted receiving shipments in April 2017.
I told the non-technical recruiter, who admitted not knowing anything about my profession but needed to screen my application, that even though I’ve not previously worked directly on WIPP, my related experiences included attending a 1980 geology summer field camp to the area, getting an underground tour of WIPP when I worked for Department of Energy in 2010, and conducting investigations at several sites that created nuclear waste being sent for disposal. So I understand generally the site geology, hydrology, and geochemistry as well as what’s inside the drums and the salt-mine repository. Specific to the geochemistry position, I mentioned several jobs I previously held including on the Yucca Mountain project, which was previously proposed as an underground repository for disposing high-level radioactive waste and spent nuclear fuel from commercial nuclear power plants.
Transuranic (TRU) waste remains radioactive for thousands of years so you might ask how are decisions made to allow for continued disposal? The EPA requires computer modeling of all the features, events, and processes known as performance assessments (PA) to calculate the anticipated radionuclide activity at the site boundary after 10,000 years. EPA initially certified the site in 1998 and requires recertification every five years with the next one due in November 2026. Here’s an example of Title 40 CFR Part 191 Subparts B and C Compliance Recertification Application from 2014.
An EPA report describes the importance of understanding the site and waste geochemical interactions that are modeled in the PA which states:
“The PA incorporates multiple different models and concepts, ranging from the rock mechanics of the surrounding salt matrix to the geochemistry of the actinides’ interacting with brine pockets. This document provides an overview of the various geochemical concepts in the PA used to estimate actinide releases and relates them to the specific conditions at the WIPP and the PA methods.”
Actinides encompass the 14 metallic chemical elements in the 5f series, with atomic numbers from 89 to 102, actinium through nobelium. Here’s an interesting historical letter describing the discovery of plutonium by Glenn Seaborg. The quote above also mentions “brine pockets” which are isolated small quantities of trapped seawater contained in salt deposits along with interbedded clay and anhydrite (calcium sulfate).
Geochemical computer codes, including EQ3/6 and PHREEQC, combine chemical analyses of water or brine with thermodynamic data to calculate the solubilities and activities or concentrations of elements which are then included in the PA. There are many assumptions and constrains on geochemical modeling, such as that chemical reactions have instantaneously achieved an equilibrium state, so tremendous expertise is needed to make sense of the data. Here’s an interesting article from 2022 by some geochemists that I previously worked with explaining how different thermodynamic datasets can influence the results.
My preparation for the interview led to learning about a geochemistry expert who became a whistleblower stating that he discovered fraud. Dr. Charles Oakes worked for Sandia National Laboratory which oversees the WIPP PA and was not able to resolve technical disagreements so after losing his job he went to court. KOB-4 News from Albuquerque reported on the case in 2022:
"“This is a case where they weren’t, not only were they not doing their job, they were claiming they were doing their job but falsifying all the evidence that went into the claims that they were doing the job," Dr. Charles Oakes said.
"The most common feared way that the radiation will get to the surface is through the flow of water," said Dr. Oakes. "There are some aquifers in the rock of the repository. One of the fears is that a well will be drilled through the repository or near to this repository and water may flow through the repository and intersect with a well bore."
Dr. Oakes said his job was to look at how much of that radioactive material would make it to the surface.
"If you do have radioactive material dissolved in the water, will it react with rocks, minerals along the way, and be removed from the water, in which you removed the threat, or will it carry on its merry way dissolved and get to the surface where it can potentially hurt people and the environment," he said.
During his time at Sandia National Labs, Dr. Oakes said he discovered inaccuracies that called into question WIPP’s long-term safety, what he believed to data errors.
Oakes said he brought it up to his bosses, the Department of Energy and even the EPA.
After he spoke up, Oakes said Sandia labeled him a problem employee and showed him the door.”
I haven’t seen the results of the lawsuit but found this recent journal article by Dr. Oakes on the differing views related to WIPP thermodynamic data and geochemical modeling. He continues to develop new models to compare with existing models used in the WIPP PA.
In addition to EPA and state of New Mexico permitting the WIPP site, additional oversight is provided by the Defense Nuclear Facilities Safety Board. They provided technical reviews on the new ventilation system and chemical contents of waste in drums.
Some of the anti-nuclear groups fighting WIPP include Stop Forever WIPP and Southwest Research and Information Center providing updates on radiation leaks from 2014 and public commenting for recertification.
A total of 14,000 shipments have been sent to WIPP as of June 2024. Originally, DOE stated WIPP would operate for 25 years and close in 2024 but with new expansion the operational date may be extended to 2083.
Overall, I believe removing nuclear waste from sites around the country is significantly important and justified if it can be done safely. Continuing to improve nuclear quality assurance must allow for differing professional opinions by improving all aspects of performance assessments and model validations.