The Interim Staff Guidance on burnup credit for pressurized water reactor (PWR) spent nuclear fuel (SNF), issued by the United States Nuclear Regulatory Commission's (U.S. NRC) Spent Fuel Project Office, recommends the use of analyses that provide an "adequate representation of the physics" and notes particular concern with the "need to consider the more reactive actinide compositions of fuels burned with fixed absorbers or with control rods fully or partly inserted." In the absence of readily available information on the extent of control rod (CR) usage in U.S.

Five commercial reactor criticals (CRCs) for the LaSalle Unit 1 boiling-water reactor
have been analyzed using KENO V.a, the Monte Carlo criticality code of the SCALE 4 code
system. The irradiated fuel assembly isotopics for the criticality analyses were provided by the
Waste Package Design team at the Yucca Mountain Project in the United States, who performed
the depletion calculations using the SAS2H sequence of SCALE 4. The reactor critical
measurements involved two beginning-of-cycle and three middle-of-cycle configurations. The

The "Summary Report of Commercial Reactor Criticality Data for Sequoyah Unit 2" contains the detailed information necessary to perform commercial reactor criticality (CRC) analyses for the Sequoyah Unit 2 reactor.

Fundamentally, a nuclear energy system uses nuclear fission to create heat, which is then available for generating electricity or other applications, including seawater desalination, heating, and production of other fuels. The nuclear energy system as currently deployed in the United States, Figure 1, consists of a number of integrated components, beginning with the natural resources required for nuclear fuel, followed by fissioning of the fuel in reactors connected to electricity generation facilities, and ending with the disposition of all wastes, including used nuclear fuel (UNF).

The comparison of different nuclear fuel cycle options has become an integral element to any analysis of the future prospects for nuclear energy, in the United States and around the world. Concerns for supply security and price volatility of fossil fuels, combined with growing resolve to reduce the emissions of greenhouse gases, have caused a general shift in attitudes towards nuclear energy. However, there are lingering sustainability concerns for nuclear energy – long term uranium supply and environmental impact – as well as concerns about the proliferation of nuclear weapons.

U.S. Nuclear Regulatory Commission Interim Staff Guidance 8 (ISG-8) for burnup credit covers actinides only, a position based primarily on the lack of definitive critical experiments and adequate radiochemical assay data that can be used to quantify the uncertainty associated with fission product credit.

Background Medical screening programs at three Departments of Energy (DOE)
nuclear weapons facilities (Hanford Nuclear Reservation, Oak Ridge, and the Savannah
River Site) have included audiometric testing since approximately 1996. This report
summarizes hearing evaluations through March 31, 2003.
Methods Occupational examinations included a medical history, limited physical
examination, and tests for medical effects from specific hazards, including audiometric
testing. Hearing thresholds by frequency for DOE workers were compared to agestandardized

Background Medical screening programs were begun in 1996 and 1997 at three Department
of Energy (DOE) nuclear weapons facilities (Hanford Nuclear Reservation, Oak
Ridge, and the Savannah River Site) to evaluate whether current and former construction
workers are at significant risk for occupational illnesses. The focus of this report is
pneumoconiosis associated with exposures to asbestos and silica among workers enrolled
in the screening programs through September 30, 2001.

Ever since the 1950s, plutonium, used in fas reactors, has been seen as the key to unlocking the vast energy resource contained in the the world's uranium reserves. However, the reductions in expected nuclear reactor installation rates, combined with discovery of additional uranium, have led to a lengthening in the perceived time interval before fast reactors, the most effective users of plutonium, will make large demands on plutonium supplies. THere are several options concerning its use or storage in the meantime.

This study examines concerns raised by the U.S. Department of Energy (DOE) in its planning for transition from active waste site management and remediation to what the department terms “long-term stewardship.” It examines the scientific, technical, and organizational capabilities and limitations that must be taken into account in planning for the long-term institutional management of the department’s numerous waste sites that are the legacy to this country’s nuclear weapons program. It also identifies characteristics and design criteria for effective longterm institutional management.