Study Design & Oversight
Yucca Mountain is driven by a number of competing goals. The technical goal is to provide long term isolation of nuclear waste from the environment until it is rendered harmless. The legal goal is to satisfy the commitment made by the U.S. Congress to the nuclear industry by 1998. The political goal is to mitigate the impacts of the site on residents of Nevada. These and many subsidiary concerns are the basis for the ongoing study and evaluation of Yucca Mountain as a possible repository.
TECHNICAL REQUIREMENTS
The driving technical requirements for the repository are the following:
10,000 year confinement - This is based on the assumption that after 10,000 years the radioactive elements will have decayed into a form no more radioactive than naturally occuring uranium ore. Releases of radioactivity to the environment are limited over that 10,000 year period.
300 to 1000 year package containment - The repository must remain a working barrier for the full 10,000 years, but waste containers are required to provide substantially complete containment for only a lesser period.
multiple barriers - "Defense in depth" is required from 1) the waste package, 2) the repository itself and 3) the host rock.
emissions levels - The Environmental Protection Agency is still defining acceptable radiation levels, no easy task given the complex escape mechanisms and the uncertainties in health effects of low level exposure. The goal is to maintain a rate of fewer than 1/10 th death per year per total population (not just Nevadans).
retrievability - At least fifty years of retrievability of the spent fuel is required, though monitoring and retrieval for 100 years is being explored.
To address the scientific and engineering criteria, a by no means all inclusive list of studies being conducted include the following broad topics:
GEOLOGY - Determining the load bearing ability, porosity, temperature stability and chemistry of the volcanic tuff at Yucca Mountain.
HYDROLOGY- Determining the groundwater flowfield, origins, depth, and historical height due to climate and tectonic influences. Determining the effects of heat-pipe condensation flows of water in fractured rocks.
CHEMISTRY - Determining the absorbtive ability of zeolite minerals for radioactive isotopes, determining the corrosive conditions of the rocks and canisters, chemistry of the isotopes.
TRANSPORTATION - Design of canisters and overpack, route designations, emergency response, materials handling, canister metallurgy.
MINING TECHNOLOGY - Tunnel boring, tunnel reinforcement, the dynamic reaction of tunnels to seismic events.
The Nuclear Waste Policy Act also defines a number of stakeholders including Indian tribes, the State of Nevada, affected units of government, nuclear ratepayers and others. To satisfy their needs, socioeconomic studies also are a part of the research being conducted and are integral to the implementation of the technical results.
Sites studied in the past include salt domes, granite structures and sub-groundwater disposal. Yucca Mountain holds an advantage over other studied sites in dryness, depth of water table, presence of zeolites, mechanical properties of the rock, lack of valuable minerals, and a number of other attributes.
STUDY EXECUTION
The study is directed by the Department of Energy Yucca Mountain Project Office under the Office of Civilian Radioactive Waste Management. Influencing the project office's direction are a multitude of governmental and private entities. Technical input from government institutions includes (but is not limited to) the following:
United States Geologic Survey
Environmental Protection Agency
National Academy of Science
Nuclear Waste Technical Review Board
National Laboratories (Sandia, Livermore, etc.)
On the private side there are two prime contractors and a variety of subcontractors. Originally, Science Applications International Corporation (SAIC) ran both characterization and support services (such as public information). In 1991, DOE hired a team of companies, led by TRW, as the management and operating contractor for the nation's Civilian Radioactive Waste Management Program. SAIC took up support duties and has continued to maintain a presence in large part because of its extensive expertise at Yucca Mountain and its knowledge of the political climate. The consortium led by TRW includes:
TRW - Prime contractor, systems engineering, design, development, technical direction, management and operation.
BABCOCK AND WILCOX - Engineered barrier design and development.
DUKE ENGINEERING - Licensing, outreach, MRS design, quality assurance.
E.R. JOHNSON ASSOCIATES - Strategic Planning and Policy Analysis
INTERA - Performance assessment.
FLUOR DANIEL - Surface facility design and development.
INTERA - Performance Assessment.
J.K. RESEARCH ASSOCIATES - Strategic planning and policy analysis.
LOGICON RDA - Systems engineering and integration support
MORRISON KNUDSON - Underground facility design.
WOODWARD-CLYDE - Site characterization.
The Office of Civilian Radioactive Waste Management and the Yucca Mountain Project Office in Las Vegas have jointly run the study of Yucca Mountain, a job that at times has been an organizational nightmare.
OVERSIGHT
Adding to the bureaucratic complexity of designing a nuclear waste repository has been the creation of multiple layers of oversight institutions. There is more oversight of nuclear waste disposal than of any other project in U.S. history. Among the most prominent oversight entities are:
NUCLEAR WASTE TECHNICAL REVIEW BOARD
NATIONAL RESEARCH COUNCIL
OF THE NATIONAL ACADEMY OF SCIENCES,
NUCLEAR REGULATORY COMMISSION
ENVIRONMENTAL PROTECTION AGENCY
UNITED STATES GEOLOGIC SURVEY
GENERAL ACCOUNTING OFFICE
OFFICE OF MANAGEMENT AND BUDGET
SENATE ENERGY AND
NATURAL RESOURCES COMMITTEE
HOUSE ENERGY AND COMMERCE COMMITTEE'S
SUBCOMMITTEE ON ENERGY AND POWER
NEVADA AGENCY FOR NUCLEAR PROJECTS
/NUCLEAR WASTE PROJECT OFFICE
Consequently, if there is one criticism of the study of Yucca Mountain, it may be that there is too much oversight of the science and engineering being conducted. This can have the unintended result of causing the project to bog down in the minutia of the study rather than pursuing a workable solution. Nevertheless, because Congress recognized that many of the actors on the stage had vested interests in certain outcomes for the repository study, one necessary level of oversight was the creation of an impartial Nuclear Waste Technical Review Board:
PUBLIC LAW 100-203
NUCLEAR WASTE TECHNICAL REVIEW BOARD
(B) The National Academy of Sciences shall nominate 22 persons for appointment to the Board who meet the qualifications described in subparagraph (C).
(C)
(i) Each person nominated for appointment to the Board shall be ---
(I) Eminent in a field of science or engineering, including environmental sciences; and
(II) Selected solely on the basis of established records of distinguished service.
(ii) The membership of the Board shall be representative of the broad range of scientific and engineering disciplines related to activities under this title.
(iii) No person shall be nominated for appointment to the Board who is an employee of---
(I) the Department of Energy;
(II) a national laboratory under contract with the Department of Energy; or
(III) an entity performing high level radioactive waste or spent nuclear fuel activities under contract with the Department of Energy.
The Nuclear Waste Technical Review Board has proven to be an irritant to DOE on a number of ocassions, and it appears to be fulfilling its oversight responsibilities in good faith. The issues of concern at Yucca Mountain stretch across a wide panorama of sciences. The main technical issues broadly divide into the areas of: on-site versus geologic storage, transportation, groundwater, earthquakes, volcanism and radiation emissions. The next chapters will address each of these issues in turn.
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