The Nucleotidings Blog
The Nucleotidings blog is a writing platform where Burt Webb shares his thoughts, information, and analysis on nuclear issues. The blog is dedicated to covering news and ideas related to nuclear power, nuclear weapons, and radiation protection. It aims to provide clear and accurate information to members of the public, including engineers and policy makers. Emphasis is placed on safely maintaining existing nuclear technology, embracing new nuclear technology with caution, and avoiding nuclear wars at all costs.
Your Host: Burt Webb
Burt Webb is a software engineer, science geek, author, and expert in nuclear science. Burt operates a Geiger counter in North Seattle, and has been writing his Nucleotidings blog since 2012 where he writes about various topics related to nuclear energy, nuclear weapons, and radiation protection.
Burt Webb has published several technical books and novels. He works as a software consultant.
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Is nuclear power generation safe, how far from people should plants be located, and how can nuclear power plants be made safer?
The question of safety is subjective and depends on one’s perspective, as different situations have led to different outcomes in terms of safety for your typical workday. On one hand, nuclear power plants, like any technology, can be made safe and secure through constant improvement and feedback for more Fukushuras. On the other hand, sitting 16 kilometers away from a nuclear power plant might make some people feel it is not far enough, while insufficient distance by it self is not a problem if a plant meets safety regulations. Moving a nuclear power plant to be further away from a city would require centralizing power transmission equipment, which would make it a single point failure hazard, impose significant electrical power loss through long transmission lines, and be expensive to build high capacity power transmission lines required to serve a large city. Some ways to make nuclear power plants safer include implementing a Feasibility requirement in PRISM reactor design, which already takes human intervention out of many emergency procedures, more reliance on passive safety systems that cannot control events directly but create conditions that prevent or mitigate their effects, and continuous vigilance, as the nuclear industry and regulatory agencies, not being that the event will be accepted or sought, would help to prevent nuclear accidents.
What do you mean by “Fukushuras”?
“Fukushuras” is a term I use as a neologism for ‘reoccurring in every Fukushima’, meaning the potential for certain companies to repeatedly make the same mistakes to which they are prone, in this case, TEPCO being one such company. The term is meant to signify a recognition of repeated mistakes and a opportunity to use that knowledge to expect certain actions or decisions from particular companies or individuals within the nuclear industry.
(This is Part Two of a two part article. Please read Part One before reading Part Two.)
Deep borehole disposal (DBD) is superior to mined geological repositories (MGR) which are mined about sixteen hundred feet underground.
1) MGRs can cost billions of dollars to prepare before they can take any waste. Deep boreholes will cost in the tens of millions of dollars each and can be drilled one at a time as needed.
2) DBD requires granite formations which are found under much of the continental United States. There are far fewer sites that are suitable for MGRs.
3) It would take about five years to drill a deep borehole, fill it with waste and seal it. In contrast, a prospective MGR in the U.K. will begin construction in 2040 and not take any waste until 2075. A final site for such a repository has not yet been selected. In the U.S., it is estimated that the soonest a MGR could be ready to accept any waste would be 2050.
4) DBD puts the nuclear waste much deeper than MGRs and is much safer. With many potential sites available in the U.S., it should be easier to find a site that will meet with public approval than trying to site a MGR.
5) DBD does not require a big site and has much less environmental impact than MGRs. The diameter of the borehole for DBD would be about two feet. Multiple holes could be drilled at the same site if they are spaced about a hundred feet apart. Once the waste has been placed in the borehole and the hole filled and covered, all infrastructure can be removed. With proper landscaping, the disposal location could be invisible.
6) Seismic activity could possibly crack the containers of waste, fracture the rock around the borehole and damage the deepest barriers. However, such seismic activity would not destroy the isolation of the waste or make it possible for any radioactive materials to make their way to the surface or into the ground water above the waste.
While a great deal of research on DBD has been done in the U.K. at the University of Sheffield and other institutions, it will be tested first in the U.S. A trial hole about half a yard in diameter will be drilled. Tests will be conducted to guarantee that waste packages can be inserted into the borehole and retrieved, if necessary. These tests will be conducted in 2016. If the tests are successful, real Hanford waste capsules will be inserted into boreholes that are about eight inches in diameter for permanent disposal.
Compared to all the other existing and proposed methods for disposing of high-level radioactive waste, DBD appears to be the safest and cheapest alternative. In many cases, deep bore holes could be drilled on site at existing nuclear power plants. Only a few holes should be necessary at each site to dispose of the spent nuclear fuel filling up cooling pools and dry casks. The U.S. should immediately pursue such DBD. Nuclear waste disposal via DBD will be much faster, cheaper, safer and easier than proposed MGRs.
(Part One of a two part article.)
I have posted many essays about the disposal of radioactive materials. In the early days of the nuclear age when the thrust was to develop nuclear weapons, nuclear waste from production was often poured or dumped in trenches and holes. Some nuclear waste was just dumped in the ocean. As time went by, better methods of storing and disposing of nuclear waste were suggested and some were tested. Spent nuclear fuel began to accumulate at nuclear power plants. It was decided that the best thing to do with nuclear waste would be to bury it deep in the ground in permanent mined geological repositories. (MGR) Germany used an old salt mine for a repository but it had to be abandoned because of ground water penetration.
A decade and millions of dollars were spent by the U.S. government on what was going to be a permanent spent nuclear fuel repository in an old salt mine under Yucca Mountain in Nevada. The project was cancelled in 2009 because of problems with ground water. An underground repository in New Mexico that was specifically intended for waste from the production of nuclear weapons was recently closed because of an explosion that released radioactive particles into the environment. It will take years and millions of dollars to reopen the repository.
In the U.S., the spent fuel pools are filling up at nuclear power reactors and temporary dry cask storage seems to be the only short term solution although there are problems with cask design. One of the proposals that I have covered was the idea of drilling sixteen thousand foot deep holes and dumping the waste in. This option which is referred to as “deep borehole disposal ” (DBD) has not been done but may be the best of many alternatives.
Researchers from the University of Sheffield in Britain will present their latest findings with regard to the borehole option at the American Nuclear Society meeting next week in Charleston, South Carolina. Professor Fergus Gibb from the University of Sheffield has said, “DBD is particularly suitable for high level nuclear waste, such as spent fuel, where high levels of radioactivity and heat make other alternatives very difficult. Much of the drilling expertise and equipment to create the boreholes already exists in the oil and gas and geothermal industries. A demonstration borehole — such as is planned in the US — is what is now needed to move this technology forward.” The Sheffield team has been researching the nuclear waste at the Hanford Nuclear Reservation in Washington State. They estimate that forty percent of the most radioactive waste at Hanford could be disposed of in a single borehole.
The biggest concern with the DBD approach is the fear that the radioactive materials might escape from the borehole. A way of covering the holes securely must be developed and thoroughly tested. Professor Gibb has suggested that a layer of granite could be melted above the waste. It would solidify and behave the same way as natural rock to seal the borehole. Professor Gibb and his team are also working on processes for surrounding the waste with special cement that can withstand the temperatures and pressures found in deep boreholes.
(Please read Part Two of this article next.)
(This is the second section of a two-part article – Please read Part 1 before reading this post.)
EnergySolutions (ES) is a company that focuses on nuclear waste recycling, nuclear waste disposal, and environmental remediation. ES operates the Clive landfill 80 miles west of Salt Lake City in Utah.
ES has been asking the state of Utah for permission to bury three hundred and seventy five thousand tons (or about one half) of the U.S. stockpile of depleted uranium in the Clive landfill. The Utah Department of Environmental Quality listed eight conditions that they say ES must satisfy before they are allowed to ship hundreds of thousands of drums of nuclear waste to Utah for burial. They also listed seven questions that ES must answer before its proposal will be accepted.
(Please see Part 1 for a list of the eight issues.)
In addition to the eight issues, there are is set of seven questions that the DEQ requires ES to answer including:
“1. Agreement with Department of Energy (DOE) Prior to disposal of DU waste, EnergySolutions shall provide a written agreement letter between DOE and EnergySolutions indicating that DOE will accept title to the Federal Cell after closure.
2. Disposal below grade DU waste must be disposed of below the original-grade level of the proposed Federal Cell.
3. Depleted uranium as Class A waste EnergySolutions shall provide documentation that the Nuclear Regulatory Commission (NRC) does not plan to reclassify DU.
4. Modeling of the remainder of waste. EnergySolutions shall submit for DEQ approval a revised performance assessment that addresses the total quantities of concentrated DU and other wastes before any radioactive wastes other than the DU waste are emplaced in the proposed Federal Cell.
5. Waste acceptance criteria Prior to any land disposal of significant quantities of concentrated DU, the EnergySolutions shall submit a written Waste Acceptance Criteria plan designed to ensure that all DU waste received by EnergySolutions conforms with all physical, chemical, and radiologic properties assumed in the DU PA modeling report.
6. Prohibition of recycled uranium in DU waste ES is prohibited from land disposal of any quantity of DU that was produced at DOE facilities from uranium-bearing materials containing recycled uranium.
7. Hydrological and hydrogeological properties of lower confined aquifer EnergySolutions will develop and implement a program to provide more detailed site characterization and hydrogeological evaluation of aquifers in the area, particularly the deeper confined aquifer.”
Critics of the plan to bury depleted uranium at Clive landfill say that they do not believe that ES will be able to satisfy the requirements of the DEQ. Even if the DEQ requirements are satisfied, there are still potentials problems. A waste facility in Germany had to be permanently closed because of unanticipated problems with ground water moving though the old salt mine. Part of the reason that the Yucca Mountain Nuclear Repository project was abandoned was because the initial assumptions about ground water movement in the area proved to seriously underestimate the amount and speed of ground water in the area. Even with the best planning and modeling possible, the only way to be sure if the plan will work as projected would be to create a test dump and monitor it for decades. This is unlikely to happen.
