Repository for high-level waste

Consider now the effects of the waste and emplacement of the waste on the hydrology of the system. Present thinking suggests that a mined underground cavity in bedded salt will be the first choice for a repository for high-level waste. The rationale for... 

The chemical behavior of waste in the unsaturated zone is a large unknown. For example, definition of the number of sorption sites available to a solute is difficult or impossible because unknown and variable amounts are occupied by interstitial gas rather than water. Are the kinetics of reaction affected by less-than-complete saturation These are not trivial questions, as most of the low-level disposal sites are constructed in the unsaturated zone. Winograd (9) suggested that certain areas underlain by thick unsaturated zones might make feasible repositories for high-level wastes. 

The generic SF/HLW repository model represents a hypothetical repository for High-Level-Waste (HLW) and Spent Fuel (SF) to he set up in a German rock salt formation. It consists of eight emplacement fields for SF, one for HLW and one for intermediate-level waste (ILW). Each emplacement drift contains three boreholes. The inner drifts are replaced by one model drift per field. Although it is rather improbable, a shaft failure scenario is selected for investigation to demonstrate that the consequences remain low even in such... 

Grambow, B. 1991. What do we know about nuclear waste glass performance in the repository near field In Sellin, P., Apted, M. Gago, J. (eds) Proceedings Technical Workshop on Near-Field Performance Assessment for High-Level Wastes, Madrid, Spain. SKB Technical Report 91-59. Stockholm, Sweden, 25-49. 

Fourth, the definitions of waste classes in the United States are not related to requirements for disposal. In IAEA s waste classification system, there is some linkage between the definitions of waste classes and the types of disposal technologies that would be required, particularly for high-level waste. However, not all waste classes in IAEA s system are linked to required disposal technologies, because low-and intermediate-level waste could be acceptable for near-surface disposal or could require disposal in a geologic repository depending, for example, on the concentrations of long-lived radionuclides. 

It appears that the repository capacity for high-level wastes will be heat-limited to one kilowatt/acre. This is equivalent to one ton of fuel after storage for ten years. The spent fuel discharged by the year 2000 will require about 2700 subterranean acres. This would be reduced to 1000 acres if the uranium and the plutonium were removed, and considerably less than that if the strontium and the cesium also were removed. Although reprocessing would reduce the transuranic content by a factor of 10 to 50, this amount would be an insignificant fraction of the transuranic hazard in the waste. 

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... 

Discuss some of the important similarities and differences in radionuclide behavior in uranium ore deposits and in geologic repositories for high level nuclear waste, as discussed in this chapter. 

For full public acceptance of nuclear power, a number of issues must be addressed, including waste disposal, reactor safety, economics, and nonproliferation. All of these issues depend on the fuel cycle that is used, but for any fuel cycle a geological repository will be needed for high-level waste storage. What will differ are the nature, hazard, half-life, and volume of the waste. 

ENRESA. 2000. FEBEX Project. Full-scale engineered barriers experiment for a deep geological repository for high level radioactive waste in crystalline host rock. Final Report. Pub. Tec. 1/2000. 354 pp. 

INTERNATIONAL ATOMIC ENERGY AGENCY, Monitoring of Geological Repositories for High Level Radioactive Waste, IAEA-TECDOC-1208, IAEA, Vienna (2001). 

The level of safety of a repository for high level radioactive wastes shall be such that the predicted risk of a health effect in a year from a repository to an individual of the critical group from disruptive events not covered by Principle No. 5 is less than a risk upper bound apportioned by national authorities from an individual limit of risk of health effects of one in a hundred thousand per year. 

A deep repository for high-level and long-lived intermediate-level waste. This type of reposi-... 

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). 

It has been traditional to subject workers to higher risks than the public, (a) Write a short discussion of the equities of this practice with consideration for the fact the worker may leave employment that imposed a long term risk, (b) The Nevada Test Site has been selected as a possible location for a high level waste repository. For purposes of the risk assessment, the workers in the repository will be treated as workers with subsequent higher allowable risk. There are many other workers at NTS. Discuss whether these should be treated as workers or public, (c) If they are treated... 

High-level wastes solidified in glass suitable for long-term isolation in aFederal repository. 

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