Yucca Mountain repository Nevada

Yucca Mountain in Nevada is a promising site for a permanent repository for nuclear wastes. Exploratory tunnels have already been drilled, and extensive tests are underway. 

Choosing the waste repository sites is an especially sensitive issue. Many states have resisted the plan, but Congress has the power to override a state s disapproval. In fact, Congress amended the Nuclear Waste Policy Act in 1987 to make Yucca Mountain in Nevada the primary potential site. Studies are now being carried out to evaluate the feasibility of this site as a safety repository for nuclear waste. 

Another waste depository, under Yucca Mountain in Nevada, may begin to store nuclear waste in the next several years. In June 2008, the Department of Energy submitted a license application to the Nuclear Regulatory Commission (NCR) to construct a repository. This process can take 3 to 4 years for approval and then more time to actually build the repository. 

Spent nuclear fuel has fission products, uranium, and transuranic elements. Plans call for permanent disposal in underground repositories. Geological studies are in progress at the Yucca Mountain site in Nevada. Until a repository is completed, spent fuel must be stored in water pools or in dry storage casks at nuclear plant sites. 

Tuff, a compressed volcanic material, is the primary constituent of Yucca Mountain, near Las Vegas, Nevada, the site selected by Congress in 1987 for assessment for spent fuel disposal. An underground laboratory, to consist of many kilometers of tunnels and test rooms, is to be cut into the mountain with special boring equipment to determine if the site is suitable for a repository. 

The primary issue is to prevent groundwater from becoming radioactively contaminated. Thus, the property of concern of the long-lived radioactive species is their solubility in water. The long-lived actinides such as plutonium are metallic and insoluble even if water were to penetrate into the repository. Certain fission-product isotopes such as iodine-129 and technicium-99 are soluble, however, and therefore represent the principal although very low level hazard. Studies of Yucca Mountain, Nevada, tentatively chosen as the site for the spent fuel and high level waste repository, are underway (44). 

Pearcy, E. C., Prokryl, J. D., Murphy, W. M. Leslie, B. W. 1994. Alteration of uraninite from the Nopal I deposit, Pena Blanca District, Chihuahua, Mexico, compared to degradation of SNF in the proposed U.S. high level nuclear waste repository at Yucca Mountain, Nevada. Applied Geochemistry, 9, 713—732. 

In 1992, Congress directed EPA to issue a new environmental standard for disposal of spent fuel and high-level waste that would apply only to the candidate geologic repository at the Yucca Mountain site in Nevada (NEPA, 1992). Thus, the existing EPA standards in... 

NRC (2001). U.S. Nuclear Regulatory Commission. 10 CFR Part 63—Disposal of high-level radioactive wastes in a proposed geologic repository at Yucca Mountain, Nevada, Final rule, 66 FR 55732 (U.S. Government Printing Office, Washington). 

Nuclear waste. The nuclear waste disposal scheme remains to be finalized. The Yucca Mountain project in Nevada has made good advances recently, and when licensed it can provide a destination for the spent fuel accumulating at the plant sites. The development of a closed fuel cycle that involves the extraction and use of the fissile contents from the irradiated fuel would reduce the long-lived radioactivity associated with the waste to be sent to the repository. 

It is considered a form of HLW because of the uranium, fission products, and transuranics that it contains. HLW includes highly radioactive liquid, calcined or vitrified wastes generated by reprocessing of SF. Both SF and HLW from commercial reactors will be entombed in the geological repository at Yucca Mountain —100 mile (1 mile = 1.609344 km) northwest of Las Vegas, Nevada. Disposal of spent nuclear fuel and HLW in the US is regulated by 40 CFR Part 191 (US EPA, 2001) and 10 CFR Part 60 (US NRC, 2001). It is discussed in more detail in a later section of this chapter. 

Introduction actinide solubilities in reference waters. In this section, the environmental chemistry of the actinides is examined in more detail by considering three different geochemical environments. Compositions of groundwater from these environments are described in Tables 5 and 6. These include (i) low-ionic-strength reducing waters from crystalline rocks at nuclear waste research sites in Sweden (ii) oxic water from the J-13 well at Yucca Mountain, Nevada, the site of a proposed repository for high-level nuclear waste in tuffaceous rocks and (iii) reference brines associated with the WIPP, a repository for TRU in... 

Tien P.-L., Siegel M. D., Updegraff C. D., Wahi K. K., and Guzowski R. V. (1985) Repository Site Data Report for Unsaturated Tuff, Yucca Mountain, Nevada. US Nuclear Regulatory Commission. 

US Nuclear Regulatory Commission (2001) 10 CFR Parts 2, 19, 20, 21, etc. disposal of high-level radioactive wastes in a proposed geological repository at Yucca Mountain, Nevada final rule. Federal Register 66(213), 55732-55816. 

Research has focused on Yucca Mountain, Nevada, at the western edge of the National Test Site, for its suitability as a nuclear waste repository for SNF and some defense waste. Many political leaders of Nevada strongly oppose this plan, and they seriously question that nuclear waste can be safely kept out of the human environment for 10,000 years, as is required under the federal Nuclear Waste Policy Act. 

The Pena Blanca deposit in northern Mexico occurs in unsaturated and oxidized rhyolitic tuffs, in a geologic and climatic setting similar to that of the proposed U.S. repository at Yucca Mountain, Nevada. Much of the original UO2 ore has been oxidized and altered, sometimes first to form U(VI) oxide hydrates such as schoepite, and later to precipitate as more stable and abundant U(VI) silicate... 

---