Conceptual structure of the 1996 performance assessment for the Waste Isolation Pilot Plant

The conceptual structure of the 1996 performance assessment (PA) for the Waste Isolation Pilot Plant (WIPP) is described. This structure involves three basic entities (EN1, EN2, EN3): (1) EN1, a probabilistic characterization of the likelihood of different futures occurring at the WIPP site over the next 10,000 yr, (2) EN2, a procedure for estimating the radionuclide releases to the accessible environment associated with each of the possible futures that could occur at the WIPP site over the next 10,000 yr, and (3) EN3, a probabilistic characterization of the uncertainty in the parameters used in the definition of EN1 and EN2. In the formal development of the 1996 WIPP PA, EN1 is characterized by a probability space (S{sub st}, P{sub st}, p{sub st}) for stochastic (i.e., aleatory) uncertainly; EN2 is characterized by a function {line_integral} that corresponds to the models and associated computer programs used to estimate radionuclide releases; and EN3 is characterized by a probability space (S{sub su}, P{sub su}, p{sub su}) for subjective (i.e., epistemic) uncertainty. A high-level overview of the 1996 WIPP PA and references to additional sources of information are given in the context of (S{sub st}, P{sub st}, p{sub st}), {line_integral} and (S{sub su}, P{sub su}, p{sub su})

Propagation of Shear-Stress Waves in an Infinite Nonhomogeneous Elastic Medium with Cylindrical Cavity

The problem of the radial propagation of shear waves in a nonhomogeneous elastic medium with a cylindrical cavity is solved by the theory of propagating surfaces of discontinuity. Thus, numerical integration that is required in using method of characteristics is avoided. An analytical solution, in the form of a Taylor series expanded about the time of arrival of the wavefront, is obtained. Two numerical examples, which are shown to agree with previous results, are also presented. © 1969, Acoustical Society of America. All rights reserved

Guest editorial: The 1996 performance assessment for the Waste Isolation Pilot Plant

The appropriate disposal of radioactive waste is a problem of great importance, wide-spread interest, and some controversy. As part of the solution to this problem the Waste Isolation Pilot Plant (WIPP) is under development by the US Department of Energy (DOE) for the deep geologic disposal of transuranic (TRU) waste generated by defense programs in the United States. The DOE submitted a Compliance Certification Application (CCA){sup 17} for the WIPP to the US Environmental Protection Agency (EPA) in October 1996, and a positive certification decision for the WIPP was issued by the EPA in May 1998. The first disposal of TRU waste in the WIPP took place in March 1999. The 1996 CCA for the WIPP was supported by an extensive performance assessment (PA) carried out by Sandia National Laboratories (SNL), with this PA often designated the 1996 WIPP PA, the 1996 CCA PA, or simply the 1996 PA. In turn, the 1996 PA was supported by site characterization activities, experimental programs, model development programs, data development programs, uncertainty and sensitivity analyses, a dedicated computational environment, a rigorous quality assurance (QA) program and a sequence of earlier PAs. Further, this PA was carried out in a regulatory environment defined by the following EPA regulations: Environmental Radiation Protection Standards for the Management and Disposal of Spent Nuclear Fuel, High-Level and Transuranic Radioactive Wastes (40 CFR Part 191) and Criteria for the Certification and Re-Certification of the Waste Isolation Pilot Plant's Compliance with the 40 CFR Part 191 Disposal Regulations (40 CFR Part 194) The WIPP is the first licensed facility in the United States for the deep geologic disposal of radioactive waste. As a result, there is extensive interest in both the WIPP and the analyses that led to its certification by the EPA for the disposal of TRU waste. The WIPP program has produced large amounts of documentation both as part of the CCA itself and in large numbers of technical reports and supporting analysis documents. Although this information is publicly available, in practice its great quantity and availability at only specific locations (e.g., EPA Docket locations, the WIPP Records Centers in Albuquerque and Carlsbad) make obtaining a detailed understanding of the 1996 WIPP PA an arduous undertaking

Use of Performance Assessment in Support of Waste Isolation Pilot Plant (WIPP) Programmatic Activity Planning

The Waste Isolation Pilot Plant (WIPP) is being developed by the U.S. Department of Energy (DOE) for the geologic (deep underground) disposal of transuranic (TRU) waste. A Compliance Certification Application (CCA) of the WIPP for such disposal was submitted to the U.S. Environmental Protection Agency (EPA) in October 1996, and was approved by EPA in May 1998. In June 1998, two separate, but related, lawsuits were filed, one against DOE and one against EPA. On March 22, 1999, the court ruled in favor of DOE, and on March 26, 1999, DOE formally began disposal operations at the WIPP for non-mixed (non-hazardous) TRU waste. Before the WIPP can begin receiving mixed (hazardous) TRU waste, a permit from the State of New Mexico for hazardous waste disposal needs to be issued. It is anticipated that the State of New Mexico will issue a hazardous waste permit by November 1999. It is further anticipated that the EPA lawsuit will be resolved by July 1999. Congress (Public Law 102-579, Section 8(f)) requires the WIPP project to be recertified by the EPA at least as frequently as once every five years from the first receipt of TRU waste at the WIPP site. As part of the DOE's WIPP project recertification strategy, Sandia National Laboratories (SNL) has used systems analysis and performance assessment to prioritize its scientific and engineering research activities. Two 1998 analyses, the near-field systems analysis and the annual sensitivity analysis, are discussed here. Independently, the two analyses arrived at similar conclusions regarding important scientific activities associated with the WIPP. The use of these techniques for the recent funding allocations at SNL's WIPP project had several beneficial effects. It increased the level of acceptance among project scientists that management had fairly and credibly compared alternatives when making prioritization decisions. It improved the ability of SNL and its project sponsor, the Carlsbad Area Office of the DOE, to demonstrate the importance of ongoing scientific and engineering activities associated with the WIPP project. Finally, it provided objective documentation of the decision-making process for issues with an impact on safety at the WIPP, a critical topic for the general public and the regulatory agencies

Regulatory basis for the Waste Isolation Pilot Plant performance assessment

The Waste Isolation Pilot Plant (WIPP) is the first operational repository designed for the safe disposal of transuranic (TRU) radioactive waste from the defense programs of the US Department of Energy (DOE). The US Environmental Protection Agency (EPA) is responsible for certifications and regulation of the WIPP facility for the radioactive components of the waste. The EPA has promulgated general radioactive waste disposal standards at 40 CFR Part 191. and WIPP-specific criteria to implement and interpret the generic disposal standards at 40 CFR Part 194. In October 1996. the DOE submitted its Compliance Certification Application (CCA) to the EPA to demonstrate compliance with the disposal standards at Subparts B and C of 40 CFR Part 191. This paper summarizes the development of the overall legal framework for radioactive waste disposal at the WIPP, the parallel development of the WIPP performance assessment (PA), and how the EPA disposal standards and implementing criteria formed the basis for the CCA WIPP PA. The CCA resulted in a certification in May 1998 by the EPA of the WIPP'S compliance with the EPA's disposal standard, thus enabling the WIPP to begin radioactive waste disposal

Summary discussion of the 1996 performance assessment for the Waste Isolation Pilot Plant

The Waste Isolation Pilot Plant (WIPP) is under development by the US Department of Energy (DOE) for the geologic disposal of transuranic waste. The construction of complementary cumulative distribution functions (CCDFs) for total radionuclide release from the WIPP to the accessible environment is described. The resultant CCDFs (1) combine releases due to cuttings and cavings, spallings, direct brine release, and long-term transport in flowing groundwater, (2) fall substantially to the left of the boundary line specified by the U.S. Environmental Protection Agency's (EPA's) standard 40 CFR 191 for the geologic disposal of radioactive waste, and (3) constitute an important component of the DOE's successful Compliance Certification Application to the EPA for the WIPP. Insights and perspectives gained in the performance assessment (PA) that led to these CCDFs are described, including the importance of (1) an iterative approach to PA, (2) uncertainty and sensitivity analysis, (3) a clear conceptual model for the analysis, (4) the separation of stochastic (i.e., aleatory) and subjective (i.e., epistemic) uncertainty, (5) quality assurance procedures, (6) early involvement of peer reviewers, regulators, and stake holders, (7) avoidance of conservative assumptions, and (8) adequate documentation

Performance assessment methodology demonstration : methodology development for evaluating compliance with EPA 40 CFR 191, Subpart B, for the Waste Isolation Pilot Plant /

"SAND89-2027.""Printed December 1989.""Prepared by Sandia National Laboratories ... for the United States Department of Energy under contract DE-AC04-76DP00789"--Cover."Sandia report."Cover title.Includes bibliographical references.Mode of access: Internet