The Analysis of the Total System Life Cycle Cost (TSLCC) of the Civilian Radioactive Waste Management Program represents the Office of Civilian Radioactive Waste Management's most recent estimate of the costs to dispose of the Nations's spent nuclear fuel (SNF) and high-level radioactive waste (HLW). This TSLCC analysis projects all Program costs through 2119 for a surrogate, single potential repository. The design and emplacement concepts in this TSLCC analysis are the same as those presented in the Monitored Geologic Repository Project Description Document.

Dear Members of the South Carolina Congressional Delegation:
Thank you all for your letter of October 27th. We appreciate hearing your views on the
Yucca Mountain project, the safety benefits of deep geologic disposal, and the
importance of the retaining the H Canyon facility at the Department of Energy’s
Savannah River Site.
In our draft report, the Commission finds that deep geologic disposal is an essential
component of a comprehensive nuclear waste management system. Your comments

This report presents studies performed to support the development of a technically justifiable approach for
addressing the axial-burnup distribution in pressurized-water reactor (PWR) burnup-credit criticality
safety analyses. The effect of the axial-burnup distribution on reactivity and proposed approaches for
addressing the axial-burnup distribution are briefly reviewed. A publicly available database of profiles is
examined in detail to identify profiles that maximize the neutron multiplication factor, keff, assess its

The ANS/ANS-8.1 standard requires that calculational methods used in determining criticality
safety limits for applications outside reactors be validated by comparison with appropriate critical
experiments. This report provides a detailed description of 34 fresh fuel critical experiments and
their analyses using the SCALE-4.2 code system and the 27-group ENDF/B-IV cross-section library.
The 34 critical experiments were selected based on geometry, material, and neutron interaction

Past efforts by the Department of Energy (DOE), the Electric Power Research Institute (EPRI), the Nuclear Regulatory Commission (NRC), and others have provided sufficient technical information to enable the NRC to issue regulatory guidance for implementation of pressurized-water reactor (PWR) burnup credit; however, consideration of only the reactivity change due to the major actinides is recommended in the guidance.

This report presents studies to assess reactivity margins and loading curves for pressurized water reactor
(PWR) burnup-credit criticality safety evaluations. The studies are based on a generic high-density 32-
assembly cask and systematically vary individual calculational (depletion and criticality) assumptions to
demonstrate the impact on the predicted effective neutron multiplication factor, keff, and burnup-credit
loading curves. The purpose of this report is to provide a greater understanding of the importance of

The purpose of this calculation report, Range of Applicability and Bias Determination for Postclosure
Criticality of Commercial Spent Nuclear Fuel, is to validate the computational method used to perform
postclosure criticality calculations. The validation process applies the criticality analysis methodology
approach documented in Section 3.5 of the Disposal Criticality Analysis Methodology Topical Report.1
The application systems for this validation consist of waste packages containing transport, aging, and

Burnup credit is an ongoing technical concern for many countries that operate commercial
nuclear power reactors. In a multinational cooperative effort to resolve burnup credit issues, a
Burnup Credit Working Group has been formed under the auspices of the Nuclear Energy Agency
of the Organization for Economic Cooperation and Development. This working group has
established a set of well-defined calculational benchmarks designed to study significant aspects of
burnup credit computational methods. These benchmarks are intended to provide a means for the

In the 1980s, a series of critical experiments referred to as the Haut Taux de Combustion (HTC)
experiments was conducted by the Institut de Radioprotection et de Sûreté Nucléaire (IRSN) at the
experimental criticality facility in Valduc, France. The plutonium-to- uranium ratio and the isotopic
compositions of both the uranium and plutonium used in the simulated fuel rods were designed to be
similar to what would be found in a typical pressurized-water reactor fuel assembly that initially had an

The U.S. Nuclear Regulatory Commission's guidance on burnup credit for pressurized-water-reactor (PWR) spent nuclear fuel (SNF) recommends that analyses be based on a cooling time of five years. This recommendation eliminates assemblies with shorter cooling times from cask loading and limits the allowable credit for reactivity reduction associated with cooling time. This report examines reactivity behavior as a function of cooling time to assess the possibility of expanding the current cooling time recommendation for SNF storage and transportation.