Since 1975, a short course entitled "System Safety and Reliability Analysis" has been presented to over 200 NRC personnel and contractors. The course has been taught jointly by David F. Haasl, Institute of System Sciences, Professor Norman H. Roberts, University of Washington, and 'members of the Probabilistic Analysis Staff, NRC, as part of a risk assessment training program sponsored by the Probabilistic Analysis Staff. This handbook has been developed not only to serve as text for the System Safety and Reliability Course, but also to make available to others a set of otherwise undocumented material on fault tree construction and evaluation. The publication of this handbook is in accordance with the recommendations of the Risk Assessment Review Group Report (NUREG/CR-0400) in which it was stated that the fault/event tree methodology both can and should be used more widely by the NRC. It is hoped that this document will help to codify and systematize the fault tree approach to systems analysis.

The U.S. Nuclear Regulatory Commission (NRC) issues licenses for the possession and use of source and byproduct materials provided that facilities meet NRC regulatory requirements and will be operated in a manner that is protective of public health and safety and the environment. Under the NRC environmental-protection regulations in the Code of Federal Regulations (CFR), Title 10, Part 51, which implement the National Environmental Policy Act of 1969 (NEPA), issuance of a license to possess and use source and byproduct materials during uranium recovery and milling requires an environmental impact statement (EIS) or a supplement to an EIS (SEIS).

If the renewed license is issued, the appropriate energy-planning decisionmakers, along with STPNOC, will ultimately decide if the reactor units will continue to operate based on factors such as the need for power. If the operating licenses are not renewed, then the facility must be shut down on or before the expiration dates of the current operating licenses-August 20, 2027, and December 15, 2028.

This environmental impact statement (EIS) has been prepared in response to an application submitted to the U.S. Nuclear Regulatory Commission (NRC) by Detroit Edison for a construction permit and operating license (combined license or COL). The proposed actions related to the Detroit Edison application are (1) NRC issuance of a COL for a new power reactor unit at the Detroit Edison Enrico Fermi Atomic Power Plant (Fermi) site in Monroe County, Michigan; and (2) U.S. Army Corps of Engineers (USACE) permit action to perform certain regulated activities on the site. The USACE is participating with the NRC in preparing this EIS as a cooperating agency and participates collaboratively on the review team.

Under normal operating conditions, cladding and core structural materials operate around 300 degrees Celsius (C), and fuel pellets experience peak temperatures below 2,000 degrees C at the pellet centerline. At these temperatures, fuel cladding integrity is maintained, and fission products are contained within the fuel rods. However, under some abnormal conditions, higher temperatures and other conditions significantly alter the behavior of these materials. These conditions can threaten core coolability and lead to fission product release. This NUREG report considers the following two types of accident conditions: (1) reactivity-initiated accidents and (2) loss-of-coolant accidents. This report describes the fuel behavior of each accident condition from basic concepts to the current state of the art. It also mentions safety criteria, references the classic experimental work in each of these areas, and presents equations and figures that permit some quantitative evaluations.

RASCAL 4 consists of several modules. Consequence assessments for nuclear power plants use five of the modules. The code invokes four of these modules when the user selects "Source Term to Dose" on the opening screen. The first module calculates the time-dependent atmospheric release source term. The atmospheric release source term is the rate at which radioactive material is released to the environment. It also includes other information that defines how the release takes place. The second and third modules perform the atmospheric transport, dispersion, and deposition calculations and the dose calculations. The fourth module is used to create the meteorological data file used by the atmospheric transport, dispersion, and deposition modules. The fifth module is used for intermediate-phase dose calculations based on field measurements. Uranium fuel cycle consequence assessments use the sixth module.