ML18221A127
| ML18221A127 | |
| Person / Time | |
|---|---|
| Site: | HI-STORE |
| Issue date: | 08/09/2018 |
| From: | - No Known Affiliation |
| To: | Office of Nuclear Material Safety and Safeguards |
| References | |
| 83FR13802 00286, NRC-2018-0052 | |
| Download: ML18221A127 (12) | |
Text
Comment A - Some hydrologic considerations for storage of High-Level nuclear waste at the Holtec Site in Lea County, New Mexico
- There are significant risks associated with present storage of spent; high-level (H/L) nuclear waste on the premises'of the nuclear power-generating facilities that generated it, particularly when they are located in densely populated areas (this risk is significant and a solutioit ts urg¢ntly needed):.'fhe Hdltec plan to use *a 1000-ac're site in
- , 1. e w~stem Lea County; New Mexic9 as. temporary stor'age for such waste in preparation for relho~al t<;> a* perma#.ent storag6*site has merit; but neither Holtec nor the Nucle'ar
- Regulatory Connilif;sioli (NRC).has guaranteed that such removal will take plate. It seems'feas1ble thai'after as much as 85;000tons of H/L waste'(estimated fotal now stored at genehiting~facility locations (~RC, 2009)) ha's heen *moved to this low-population, low-rainfall site and placed in shallow storage crypts, much of the national concern over the present storage* problem would abate, and nothing further would be done to move the waste to secure, permanent, safe storage elsewhere (spec1fically to WIPP 15 miles to the SSW Figure l ).
WIPP is. not currently authorized for storage of H/L waste, but if it can be re-authorized for such use, the following conditions are proposed to force NRC to base Commissioning of the HS on a guarantee of waste removal to WIPP within a reasonable time frame. However, until WIPP is so re-authorized, the HS commissioning should be postponed or abandoned. It is worth noting that the U S House of Representatives has recently passed a bill to re-start the process of building the Yucca Mountain Nuclear storage facility in Nevada (the Senate has not yet passed this bill). The bill would also fund the Department of Energy (DOE) to license a temporary nearby site to store spent waste while the project is being finished.
Conditions for Commissioning the Holtec Site in Lea County The NRC must guarantee that a move of spent nuclear fuel from HS to permanent storage at WIPP will be started within the first 20 'years after commissioning has taken place and finished before 50'years from comhlissioning. The 50-year time line is '
suggested to limit the arriount oftime that waste is kept at HS, and to provide assurance*
of the on:going integrity of NRG-approved.packaging for.this temporaryitorage. If such
- a-guarantee is not 6btained, storage at the Site should not be started until Holtec proves through rigorous.scientific stu~y similar to what took:place in* warranting Yucca>.
Mbuntain*a:s*:sate,'tliatrio long-lived radiomidides frdni the Site would travel ano be found within'the Accessible Environment (AE) during a 10,000-year.period after burial.
As an aside, after placement at the HS, should storage of spent-fuel radionuclides be allowed tci hecome long-term, there is an open question as to whether' the* NRC would automatically be in violation of existing Rules - that is, the presence of high-level waste within shallow mounds that could be interprete~ as part of the Accessible Environment.
SUNS! Review Complete Template= ADM-013 E-RIDS=ADM 03 ADD= Antoinette Walker-Smith, Jill Caverly (JSC 1)
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COMMENT (286)
PUBLICATION DATE: 3/30/2018 CITATION # 83 FR 13802
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If long-term storage is attempted at the HS, it seems hypothetically possible within 10,000 years for containment vessels and their concrete housings to fail, after which contained radionuclides could be released to travel downward with rain-generated recharge events as multiple contaminant fronts. Examples ofthree possible paths of contaminant transport are presented here to illustrate the complexity and danger inherent in long-term storage at HS. These scenarios were generated largely from web-based sources of information, and without review from local NM State or Federal-Agency personnel. It is strongly recommended that the US Geological Survey (USGS), the DOE, the Union of Concerned Scientists, and the Texas Water Development Board review the geo-hydrologic and geochemical analyses in this document.
A)
Isolated aquifer - f i~mt 2 shows the location of 7 playa lakes located near HS. A survey of playas in New Mexico (Playa Lakes Joint Venture 2016) indicates that these lakes all contain saline water. Satellite photos were used to outline a bleached zone around these lakes comprising a sizable area underlain by unconsolidated sediment where surficial vegetation has been affected (?)
by saline waters within a Playa Area, (PA - the PA and its lakes may be associated with deep dissolution of the salt section by upwelling waters from the underlying Capitan Reef aquifer (Bachman, 1987)). These same photos were also used to establish the location of surface channels outside the PA along which rain-generated runoff could carry water into the PA allowing downward infiltration to the water table but also causing run off downslope out of this area to the SW into Nash Draw (Figure I - the land surface around HS slopes to the SW - Figure 3, Corhet, I 996 ). It is probable that an isolated water-table aquifer now exists within the PA (Holtec has documented shallow water levels within unconsolidated sediment below HS and they report that depth to water was often less that 15 feet.). Over longer time frames, random rain-generated surface-water inflows into the PA accompanied by infiltration into the underlying aquifer could cause (periodic ?) downslope ground water flow through this aquifer from NE to SW. Such ground water flow could carry contaminants from any cask leakage that travelled down into such sediments out of the PA and into the Accessible Environment (AE) down gradient to the SW, including into lakes within the PA, and into shallow flow in Nash Draw.
This potential problem could be rectified by moving the HS away from the PA to nearby bedrock (Triassic fine-grained outcrops with their cation exchange capacities ?), but risks associated with a new location should be fully re-evaluated.
B) - Dockum Aquifer - Upper Triassic outcrops are found to the immediate north, west, and south of HS (Bachman, 1987 (Figure 4) and N M Bureau of Geology, 2003, geologic maps) and it is possible that older Triassic Dockum strata (including its basal aquifer) could be found beneath the HS. If basal sand aquifers within the Dockum are present below the HS, downward
traveling contaminant fronts from HS could be entrained in ground-water flow within this aquifer and transported to the south and southeast towards commercial pumping centers (accessible environment) in southern Lea County, NM and Winkler County, TX (b~ mg ?008
~ ater le",1 mJp (f I re J flo line m'i p11m1 *1ut. m 1p Figure 6)), or possibly flow directly into the Pecos River in Ward County, Texas (f 1purc 5) and from there into the Rio Grande. Until subsurface work is done to check on the presence or absence of the Dockum aquifer below HS ( or below a new location if the HS is moved), this problem is only a potential hazard. If geologic work is done to investigate this issue, it should be reviewed by independent agencies such as the USGS, the NM Bureau of Geology, and the NM.
C)
- Rust I I Aquill.r - the Permian Rustler Formation and its aquifers lie beneath the HS (Ba h an 1487 M... p of Rustler f-<rn - f1gu1c 7). Deeper vertical contaminant transport through and below the Triassic within the bounds of HS could reach the Rustler Formation and there, contaminants could be transported southward in ground-water flow within this confined aquifer, and eventually taken into the Pecos River itself (Corbd I 996 \\\\-c.ttr lt:\\.d mar v.1th tlov. line" I 1gure 8) - and once again, eventually into the Rio Grande..
Hale (1945) suggested that saline waters within the Rustler Aquifer did flow into the Pecos River within New Mexico in the reach between Malaga Bend and the Texas State line (figure 7). Within their modeled area (fl~urc. 7),
Corbet and Knupp (1996) describe the Rustler close to the Pecos River as grading into a permeable collapse breccia through which Rustler aquifer water within the modeled area flows into the Pecos River.
It is not known for any of the three scenarios whether such transport of contaminants from the HS could reach accessible environments (AE) within the EP A/NRC-mandated 10,000-year limit (some routes would reach the AE faster than others). It should be incumbent on Holtec and the NRC to fully evaluate these and related questions with field work, contaminant transport evaluation/modeling, and with associated (existing?) ground-water flow modeling for these three and other related aquifer systems (with critical review by USGS and DOE personnel) before approving the HS and allowing the Holtec storage to become long-term.
The NRC should be encouraged to limit the amount of spent-fuel storage at the Holtec Site to no more than 1/2 of the total available at the time of Commissioning. This will force use of at least one other permanent burial site besides WIPP (e.g., Nevada's Yucca Mountain) in order to keep the risk of burial from being placed on just one State or one type geo-hydrologic system.
References
George O Bachman, 1987, Sandia National Laboratory, Contract Report Sand86-7078, "Karst in Evaporites in Southeast New Mexico, 82 pages.
Robert O Bradley, 2003, Texas Water Development Board Report 359, "The groundwater resources of the Dockum Aquifer in Texas", 73 pages.
T F Corbet and D M Knupp, 1996, Sandia National Laboratory Report Sand96-2133, "The role of Regional groundwater flow in the hydrology of the Culebra Member of the Rustler Formation at the Waste Isolation Pilot Project (WIPP), Southeast New Mexico, 145 pages.
John Ewing et al, 2008, Texas Water Development Board Report, "Groundwater availability model for the Dockum Aquifer".
John Ewing et al, 2012, Texas Water Development Board Report, "Groundwater Availability Model for the Rustler Aquifer", 400 pages.
George et al, 2011, Texas Water Development Board Report 380 The Aquifers of Texas" WE Hale, 1945, New Mexico State Engineers, 16th and 17th Biennial Report, "Groundwater conditions in the vicinity of Carlsbad, New Mexico."
Playa Lakes Joint Venture, 2016, "Playa lakes in Colorado, Kansas, Nebraska, New Mexico, Oklahoma, and Texas".
New Mexico Bureau of Geology, 2003, Geologic map of New Mexico US Nuclear Regulatory Commission, 2009, "Spent Fuel Storage in pools and dry casks."
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