Mitigating Nuclear Hazards - Part 1 Overview

(Originally posted June 3, 2019)

To discuss my experience with mitigating nuclear hazards, I like to say that I am the only person I know of who has worked on almost every aspect of the nuclear fuel cycle. Please let me know if you know anyone else making such a bold claim so perhaps we can gain their perspective? Groups that gave me this experience include the University of Wyoming, U.S. Nuclear Regulatory Commission, U.S. Department of Energy, Lawrence Berkeley National Laboratory as well as several consulting assignments.

Ironically, in the U.S. we do not have a complete nuclear fuel cycle so a person would need to work with the French on reprocessing spent fuel to go full circle. The examination of the nuclear fuel cycle for mitigating hazards is relevant to nations and taxpayers under the construct of Conserve & Pro$per on many levels that will be discussed.

As shown on the figure, the nuclear fuel cycle is the process necessary to generate electric power (as well as medical isotopes) in a reactor. The cycle begins with mining, involves several steps to produce and burn fuel rods, store spent fuel, then ultimately burial in a engineered-geological repository. As discussed on my blog post about the Green New Deal, we all use nuclear energy, which accounts for about 20% or one-fifth of our electricity generated in the U.S. So even for the anti-nuclear activists, we all must be aware of the risks and costs involving the nuclear fuel cycle including the fact that we must properly deal with existing nuclear waste.

I will need many blog postings to explain my experience with the nuclear fuel cycle and provide examples of mitigating nuclear hazards. Here is my proposed outline to be provided in upcoming blog posts:

1. Overview

2. Uranium Mining

3. Uranium Mills and Clean Up

4. Yellowcake Conversion, Enrichment, and Fuel

5. Nuclear Reactors - Operations, Relicensing, and Decommissioning

6. Spent Fuel Storage

7. High-level Waste Disposal

8. Accidents

Thanks for your support and interest!

Mitigating Nuclear Hazards - Part 4, Fuel

I rejoined NRC in 1999 until 2005 and got involved with nuclear waste disposal, uranium mill tailings sites, relicensing nuclear power plants, the 9/11 response to terrorism and the incident response operations center (IROC). Supporting the IROC involved conducting exercise drills to simulate various threats and potential to actual emergency situations involving numerous federal and state agencies. I provided maps using Geographical Information Systems (GIS) to show nuclear facilities, roads, population information and more. The center became an exciting place for observing how natural events like hurricanes could create storm surges hitting nuclear power plants which either kept operating or needed to shut down. One time while we were practicing a drill, we got a call from a facility that a truck driver transporting uranium hexafluoride (UF6) was missing. We launched into emergency mode for about an hour trying to obtain information on the transportation routes until the driver called into to the facility to say he had overslept on the side of the road!

So what is UF6 and how does processed uranium U3O8 “yellowcake” (as described in the previous blog) become fuel that is needed to operate nuclear reactors? Yellowcake is sent in 55-gallon drums to conversion plants to remove impurities and is converted to UF6 gas. The process is described by NRC and the World Nuclear Association with conversion plants located worldwide. The primary hazard is potential chemical exposure to inhaling the gas. Waste byproducts are produced and sites have contaminated groundwater, such as at the Sequoyah Fuels site in Oklahoma. NRC has reviewed and approved several license applications to construct new conversion plants that are on hold.

The UF6 canisters are then sent to a fuel enrichment facility where U-235 isotopes are concentrated from about 0.7% to up to 5%. The gas centrifuge process is currently the preferred method and only one plant operating in the U.S. is located in southeastern New Mexico.

A major byproduct of uranium enrichment is called “depleted uranium” (where the material contains about 0.3% U-235). According the the NRC, ”if an enrichment facility processes 1,000 kilograms (kg) of natural uranium to raise the U235 concentration from 0.7 percent to 5 percent, the facility would produce 85 kg of enriched uranium and 915 kg of depleted uranium.” Depleted uranium is used for military and aviation applications.

The 9/11 terrorist attack of crashing 747 airplanes into the World Trade Center, the Pentagon, and in Pennsylvania, horrified the world. From our office in Rockville, Maryland at the NRC — we could see the fire from the Pentagon. I was the acting technical assistant to the Nuclear Materials Safety and Safeguards (NMSS) office director and immediately became tasked to join a committee to review all protective measures, such as at nuclear power plants. I was not aware that depleted uranium could have be used as ballast in aircraft and felt more incredibly shocked when the EPA Administrator told first responders that it was safe to breath the air at ground zero!

Here is an interesting article on the IAEA website about the properties, uses and primary concerns of breathing depleted uranium. U-238 follows a decay chain of radioactive daughters including radium and radon that is hazardous to breath where it comes from natural or refined sources.

There is a tremendous amount of depleted uranium waste byproduct requiring disposal. Hundreds of thousands of metric tons are stored at enrichment plants in Portsmouth, Ohio, and Paducah, Kentucky. GAO advocated for DOE to sell depleted uranium back to industry for use as a fuel which competes with uranium supply, causing downward pressure on prices, which is generally opposed by industry. Recently, DOE Secretary Perry agreed to limit supplies of domestic and Russian non-proliferation materials provided to the open market.

The enriched uranium is then sent to fuel fabrication plants to produce uranium dioxide powder that is compressed into pellets inserted into Zircoloy tubes for the fuel assembly.

Overall, there is significant processing and transportation required to produce nuclear fuel and most of the risks are chemical rather than radiological. The fuel rods do not become radioactively “hot” until they are used for starting the nuclear chain reaction at the reactor as will be described in the next blog.

Mitigating Nuclear Hazards - Part 2, Mining

Today, the National Mining Association (NMA) and U.S. Nuclear Regulatory Commission (NRC) are holding the second day of their annual Uranium Recovery Workshop in Denver, Colorado. The meeting brings together mostly industry consultants and government officials to provide a status of uranium mining in America. Uranium production within the U.S. mostly comes from in-situ recovery (ISR) uranium mines located in Wyoming as well as one operating mill in Utah; however, because the U.S. only holds about 1% of the world’s supply, the bulk of the uranium needed to fuel nuclear power plants comes from other countries.

Worldwide about half are conventional mines (open pits and underground workings) and half are ISR mines. Australia holds about 30% of the world’s supply but currently only produces about 10% according to the World Nuclear Association. The largest supplier of uranium in the world is the former Soviet Republic of Kazakhstan which produces about 39% of the world’s supply of uranium. The other big producer is Canada providing about 22% of world uranium supply.

In 1984, I completed my Master’s of Science geochemistry thesis at the University of Wyoming on the in-situ recovery (ISR) process to extract uranium ore using groundwater well fields. The ore is typically found in sandstone deposits within confined aquifers where uranium was deposited in the absence of oxygen in contact with carbon and removed with ISR by injecting oxygen and chemicals to change the acid or base content as measured by pH. This is depicted in the Wyoming Geological Survey figure as yellow oxidized sandstone and the darker colored reduced-zone ore deposit. The ISR mine injects chemicals to remove the uranium. What I found based on laboratory testing was that the ISR process to remove uranium seemed quick and efficient; however, great effort would be needed to restore the aquifer back to pre-mining conditions and that rock-water-gas interactions must be understood. Here is what EPA currently says about mitigating hazards at ISR mines.

In 2007, the price of uranium spiked due to low supply and increasing demand (as well as stock market speculation) to prices around $136 per pound, an increase of about 20 times in four years. This resulted in a resurgence of mining applications and NRC prepared a Generic Environmental Impact Statement (GEIS). I had worked at NRC just two years prior and was very familiar with the regulatory process for reviewing license applications. At that time as an independent consultant, I wrote a journal article to provide my public comments on mitigating hazards for ISR mining and aquifer restoration. I advocated the need for site-specific EIS reports to which NRC eventually agreed! Here is link to the blog and article and background information on the importance of the National Environmental Policy Act. I shared this article at the 2008 NMA Uranium Recovery Workshop in Denver to create discussions on both sides of industry and regulators.

On March 11, 2011, the 9.0 earthquake and tsunami in Japan devastated coastal communities and the Fukushima Daiichi nuclear power plant. The nuclear disaster also sent shock waves through the industry initially causing demand to be cut, uranium prices to fall, and declines in mining production. However, as I will discuss in an upcoming blog on nuclear power, demand for uranium is rising as a source of zero-carbon energy production.

In January 2013, the U.S. Congress directed my office at the Department of Energy, Office of Legacy Management (DOE-LM) to evaluate old uranium mines that were operated by the Atomic Energy Commission (AEC) from about 1948 to 1970. I took on responsibility for managing the report on location and status of mines; based on permit records we found 4,225 mines that we reported to Congress. This report, delivered in 2014, spurred a new program to field locate and assess hazards at federal uranium mine sites. Hazards might include physical safety hazards from open shafts or chemical and nuclear hazards from hills of waste rock and low grade ore deposits. Here is a 2017 DOE-LM fact sheet on the process and preliminary results.

In December 2016, I took on an additional assignment at DOE-LM as program manager of the Uranium Leasing Program. AEC reserved 25,000 acres on public lands in Colorado for uranium mining. My efforts involved resolving a lawsuit filed under NEPA and the Endangered Species Act. Here is an article by the environmental litigants that sued DOE in 2011 and the case was resolved by the U.S. District Court in March 2018, just one month before my retirement! This appears to be a win-win solution for both sides.

During my 35-year career and currently renewed opportunity to express my independent opinion, I’ve observed very strong views of people in favor of uranium mining and nuclear power as well as strongly opposed anti-nuclear activists. Information coming from both sides is often skewed and obtaining the true facts is opaque. I’ve attempted throughout my environmental science career to stay neutral and find ways to improve the environment and public health by joining others to take positive actions. The most important action in resolving differences could be through more transparency and debate such as using NEPA public meetings before going to court to consider the benefits and risks of uranium mining worldwide. Mitigating the hazards of mining uranium in the U.S.and other countries might well be worth the risks of having (or not having) a dependable domestic supply of uranium needed for nuclear power generation of electricity. Public support for increasing regulatory oversight will cost more to consumers but is greatly needed to increase environmental protections and prevent or mitigate nuclear hazards.

Please share your views in the comments or send email to info@conserve-prosper.com.