The U.S. Nuclear Waste Technical Review Board met last week to discuss the Deep Borehole Field Test. The U.S. Department of Energy wants to spend $80 million to drill two holes three miles deep in which to dump nuclear waste:
At that depth, even if the nuclear waste canister and melted granite capping leaked, the radioactive materials would supposedly never seep back up to the groundwater a couple miles above. Six such holes could store all of the United Kingdom’s nuclear waste. A single borehole could hold 40% of the nuclear waste (yum, plutonium!) stored at the Hanford dump in Washington State.
Boreholes could be built and filled more quickly and cheaply than mine-style repositories like one proposed for but halted at Yucca Mountain in Nevada; a comparable federal repository isn’t expected to be available until 2048; DOE and Sandia National Labs say these deep boreholes can be constructed in five years.
Drilling for the Deep Borehole Field Test would start in September 2016.
An April 2015 technical paper lays out these criteria for Deep Borehole Field Test sites:
- Less than 2 km (1.2 miles) depth to crystalline basement
- Not at or proximate to a strategic petroleum reserve site
- Not near an urban area 2
- Site area greater than 1 km (about 1⁄2 square mile so that there is ample area for drilling operations)
- Distance greater than about 100 km (about 60 miles) to topographic slope of greater than 1o to avoid deep groundwater circulation 2
- Geothermal heat flux less than 75 mW/m
- Less than 2% probability within 50 years of peak ground acceleration greater than 0.16 g from a seismic event (generally indicative of area of tectonic stability)
- Distance to Quaternary age (< 2.6 million years ago) volcanism greater than 10 km (6.2 miles)
- Distance to Quaternary age faulting greater than 10 km (6.2 miles)
- No known major crystalline basement shear zones or major tectonic features
- Low density of petroleum drilling
- Lack of known existing surface or subsurface anthropogenic radioactive contamination [Frank V. Perry, Bill W. Arnold, and Richard E. Kelley, “A GIS Database to Support Siting of a Deep Borehole Field Test,” IHLRWM 2015, Charleston, SC, April 12-16, 2015, p. 633]
Northeastern South Dakota satisfies many of those criteria. Sandia National Labs agrees: Sandia selected and evaluated three areas as representative locations for the Deep Borehole Field Test: the Texas Panhandle, southern South Carolina, and northeastern South Dakota. Here’s some of what a September 2014 report from Sandia said about the South Dakota site:
Much of South Dakota exhibits characteristics that are potentially favorable for the deep borehole field test, based on the siting guidelines identified in DOE (2013). Depth to crystalline basement rocks is less than 2,000 m with the exception of the northwestern corner of the state (see Figure 2-3), which lies on the southern edge of the Williston Basin. Except for the Black Hills in the southwestern part of South Dakota, topographic relief is generally low, which would tend to limit deep circulation of meteoric groundwater. Seismic risk is low (see Figure 2-2) and Quaternary age volcanism and faulting are absent in the state. Although structural complexity exists in the Precambrian basement, these features are geologically old and major features such as the Midcontinent Rift system are absent. A significant positive geothermal anomaly is present in the south-central part of the state (see Figure 2-1), but conditions elsewhere appear to be generally unfavorable to deep geothermal exploration or development. Major areas of oil and gas production are limited to the northwest and southwest corners of South Dakota, although scattered petroleum exploration drilling has occurred throughout the state. The location of the state in the stable continental interior and the geological data indicate a tectonically quiescent environment [Bill W. Arnold, Patrick Brady, Mark Sutton, Karl Travis Robert MacKinnon, Fergus Gibb, and Harris Greenberg, Sandia National Laboratories, “Deep Borehole Disposal Research: Geological Data Evaluation, Alternative Waste Forms, and Borehole Seals,” Sandia National Laboratories for U.S. Department of Energy, 2014.09.05].
Sandia focused its research on the area of South Dakota marked in the red rectangle below, since the sedimentary layer there is even shallower, generally less than 1,000 meters:
We’ve seen evidence that Governor Dennis Daugaard supports bringing nuclear waste to South Dakota. Sandia National Labs has a well-placed friend here in South Dakota, their former consultant Heather Wilson, who is now president of the South Dakota School of Mines and Technology, whose geology experts would play a key role in advising the state in inviting such a project to our bedrock.
Recall that Governor Bill Janklow tried to bring nuclear waste to the opposite corner of the state in the early 1980s. South Dakotan revolted and blocked the Edgemont nuclear waste dump plan in a 1984 ballot initiative that passed 62% to 38%. Perhaps the Governor will want to consider whether voters would respond any more favorably to having nuclear waste trucked into the heart of South Dakota’s farm and pheasant land.
Update 10:40 CDT: I’m reminded to read my own archives. The last time this blog discussed the Daugaard Administration’s hankering for nuclear waste, the Governor’s Office shared with the press a February 22, 2012, letter to U.S. Energy Secretary Steven Chu regarding research on using South Dakota shale deposits for nuclear waste disposal. In that letter, Governor Daugaard said he could “see no reason not to conduct this research, as long as this proposition does not obligate the state of South Dakota to accept nuclear waste. Any such decision will be made based on the results of rigorous scientific study and a vote by the citizens of South Dakota. I will not support the storage of spent nuclear fuel in South Dakota without an affirmative public vote.”