Preliminary Analysis of Important Site-Specific Dose Assessment Parameters and Exposure Pathways Applicable to a Groundwater Release Scenario at Yucca Mountain

1995 ◽  
Vol 412 ◽  
Author(s):  
P. A. Laplante ◽  
S. J. Maheras ◽  
M. S. Jarzemba
Keyword(s):  
Environmental Protection Agency ◽  
Nuclear Regulatory Commission ◽  
Yucca Mountain ◽  
Dose Assessment ◽  
Total System ◽  
Transfer Factors ◽  
Site Specific ◽  
Exposure Pathways ◽  
Importance Analysis ◽  
Regulatory Commission

AbstractTo develop capabilities for compliance determination, the Nuclear Regulatory Commission (NRC) conducts total system performance assessment (TSPA) for the proposed repository at Yucca Mountain (YM) in an iterative manner. Because the new Environmental Protection Agency (EPA) standard for YM may set a dose or risk limit, an auxiliary study was conducted to develop estimates of site-specific dose assessment parameters for future TSPAs. YM site-relevant data was obtained for irrigation, agriculture, resuspension, crop interception, and soil. A Monte Carlo based importance analysis was used to identify predominant parameters for the groundwater pathway. In this analysis, the GENII-S code generated individual annual total effective dose equivalents (TEDEs) for 20 nuclides and 43 sampled parameters based upon unit groundwater concentrations. Scatter plots and correlation results indicate the crop interception fraction, food transfer factors, consumption rates, and irrigation rate are correlated with TEDEs for specific nuclides. Influential parameter groups correspond to expected pathway behavior of specific nuclides. Results for nuclides that transfer more readily to plants, such as 99Tc, indicate crop ingestion pathway parameters are most highly correlated with the TEDE, and those that transfer to milk (59Ni) or beef (79Se, 129I, 135Cs, 137Cs) show predominant correlations with animal product ingestion pathway parameters. Such relationships provide useful insight to important parameters and exposure pathways applicable to doses from specific nuclides.

Proceeding Toward a License Application for U.S. Nuclear Waste Repository: Total System Performance Assessment Approach

2003 ◽  
Author(s):  
Jerry McNeish ◽  
Peter Swift ◽  
Rob Howard ◽  
David Sevougian ◽  
Donald Kalinich ◽  
...  
Keyword(s):  
Performance Assessment ◽  
System Performance ◽  
Nuclear Regulatory Commission ◽  
The United States ◽  
Yucca Mountain ◽  
Nuclear Waste Repository ◽  
Total System ◽  
License Application ◽  
Regulatory Commission ◽  
The U.S

The development of a deep geologic repository system in the United States has progressed to the preparation of an application for a license from the U.S. Nuclear Regulatory Commission. The project received site recommendation approval from the U.S. President in early 2002. The next phase of the project involves development of the license application (LA) utilizing the vast body of information accumulated in study of the site at Yucca Mountain, Nevada. Development of the license application involves analyses of the total system performance assessment (TSPA) of the repository, the TSPA-LA. The TSPA includes the available relevant information and model analyses from the various components of the system (e.g., unsaturated geologic zone, engineered system (waste packaging and drift design), and saturated geologic zone) (see Fig. 1 for nominal condition components), and unites that information into a single computer model used for evaluating the potential future performance or degradation of the repository system. The primary regulatory guidance for the repository system is found in 10 CFR 63, which indicates the acceptable risk to future populations from the repository system. The performance analysis must be traceable and transparent, with a defensible basis. The TSPA-LA is being developed utilizing state-of-the-art modeling software and visualization techniques, building on a decade of experience with such analyses. The documentation of the model and the analyses will be developed with transparency and traceability concepts to provide an integrated package for reviewers. The analysis relies on 1000’s of pages of supporting information, and multiple software and process model analyses. The computational environment represents the significant advances in the last 10 years in computer workstations. The overall approach will provide a thorough, transparent compliance analysis for consideration by the U.S. Nuclear Regulatory Commission in evaluating the Yucca Mountain repository.

Preferential Radionuclide Release Due to Alpha Decay: Effects on Repository Performance

2004 ◽  
Vol 824 ◽  
Author(s):  
David A. Pickett ◽  
William M. Murphy
Keyword(s):  
Nuclear Waste ◽  
Spent Nuclear Fuel ◽  
Alpha Decay ◽  
Nuclear Regulatory Commission ◽  
Yucca Mountain ◽  
Total System ◽  
Secondary Phases ◽  
Regulatory Commission ◽  
Radionuclide Release ◽  
The U.S

AbstractWe model preferential release of 237Np, 234U, 230Th, 226Ra, and 210Pb from disposed commercial spent nuclear fuel as a result of alpha recoil damage, using the U.S. Nuclear Regulatory Commission (NRC) Total-system Performance Assessment (TPA) model for the potential repository at Yucca Mountain. Time-dependent augmentation of the ingrown component is simulated by increasing the initial parent inventory; we have used a factor of five increase, based on natural system observations. For 237Np, the magnitude of preferential release is subject to solubility limits. Stochastic TPA runs show a significant effect on modeled dose of preferential 237Np release, but low impact from the other four radionuclides. The mechanism could be ineffective if 237Np is incorporated into secondary phases. While our results are exploratory in nature, this approach to modeling decay-related enhancement of release can be applied in other nuclear waste disposal settings.

scholarly journals Functions of the Materials Review Board

1984 ◽  
Vol 44 ◽  
Author(s):  
M. J. Steindler ◽  
W. B. Seefeldt
Keyword(s):  
Nuclear Waste ◽  
Environmental Protection Agency ◽  
Nuclear Regulatory Commission ◽  
Department Of Energy ◽  
Waste Package ◽  
Performance Predictions ◽  
High Level Nuclear Waste ◽  
Regulatory Commission ◽  
High Level ◽  
Nuclear Waste Policy

Some nuclear waste is destined for disposal in deep geological formations. The disposal system for wastes from commercial nuclear activities, and perhaps also for high-level wastes from defense-related activities, is to be designed and operated by the Department of Energy (DOE) and licensed by the Nuclear Regulatory Commission (NRC). The Nuclear Waste Policy Act [1] outlines some of the procedures and schedules that are to be followed by DOE in carrying out its assignment in the disposal of high-level nuclear waste (HLW). The regulations of the NRC that deal with HLW [2] are only partly in place, and amendments (e.g., related to the unsaturated zone) are yet to be approved and issued. The Environmental Protection Agency (EPA) has issued only draft versions of the regulations pertaining to HLW disposal [3], but key features of these drafts are at present in adequate agreement with NRC documents. On the basis of the trends that have become evident in the last few years, the DOE will be required to substantiate performance predictions for all pertinent aspects of a repository, especially the performance of the engineered waste package. The basis for demonstrating that the waste package performance in the repository will be in concert with the requirements is data on the waste package materials. These key materials data must clearly be highly reliable, and DOE will be required to assure this reliability. This paper addresses the organization and functions that have been assembled to aid in establishing the quality of materials data that are important in the licensing of a waste repository.

Practical Considerations of Site Clearance

2003 ◽  
Author(s):  
Thomas S. LaGuardia
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Regulatory Commission ◽  
Radioactive Material ◽  
Site Specific ◽  
Exposed Individual ◽  
The Us ◽  
Pathways Analysis ◽  
Residual Radioactivity ◽  
Regulatory Commission

The US Nuclear Regulatory Commission (NRC) established criteria for acceptable residual radioactivity related to decommissioning nuclear power plants in the US [1]. A level of 25 mRem per year to the maximum exposed individual by site-specific pathways analysis, with ALARA is acceptable to the NRC. Systems and structures containing very low levels of radioactivity that meet this criteria are deemed acceptable to abandon in place as part of the decommissioning process and termination of the license. Upon license termination by the NRC, the owner may then demolish and remove remaining structures. In practice, site-specific criteria imposed by local state mandates, company management decisions, real estate value, and long-term liability potential have driven nuclear plant licensees to adopt an alternative disposition for these materials. Although the reasons are different at each site, the NRC’s criteria of 25 mRem per year are not the controlling factor. This paper will describe the regulatory process for termination of the license, and the other factors that drive the decision to remove radioactive and non-radioactive material for decommissioning. Several case histories are presented to illustrate that the NRC’s criteria for license termination are not the only consideration.

An Analysis of Waste Package Behavior for High-Level Waste

1982 ◽  
Vol 15 ◽  
Author(s):  
Margaret S. Chu ◽  
James E. Campbell ◽  
Stephen E. Stuckwisch ◽  
Krishan K. Wahi ◽  
Malcolm D. Siegel
Keyword(s):  
Environmental Protection Agency ◽  
Nuclear Regulatory Commission ◽  
High Level Waste ◽  
Protection Agency ◽  
Waste Package ◽  
Draft Standard ◽  
Geologic Disposal ◽  
Waste Repository ◽  
Regulatory Commission ◽  
High Level

The Environmental Protection Agency (EPA) has issued a draft standard (40CFR191) [1] which specifies permissible limits for radionuclide releases from a high-level waste repository to the accessible environment. The U. S. Nuclear Regulatory Commission (NRC) has published a proposed rule (10CFR60) [2] which contains technical criteria for geologic disposal of high-level waste to facilitate compliance with the EPA Draft Standard. The three main numerical criteria specified in 10CFR60 are:

scholarly journals Carbon-14 in Waste Packages for Spent Fuel in a Tuff Repository

1986 ◽  
Vol 84 ◽  
Author(s):  
R. A. Van Konynenburg ◽  
C. F. Smith ◽  
H. W. Culham ◽  
H. D. Smith
Keyword(s):  
Environmental Protection Agency ◽  
Cosmic Ray ◽  
Nuclear Regulatory Commission ◽  
Spent Fuel ◽  
Moist Air ◽  
Protection Agency ◽  
Carbon 14 ◽  
Regulatory Commission ◽  
Global Inventory

AbstractCarbon-14 is produced naturally by cosmic ray neutrons in the upper atmosphere. It is also produced in nuclear reactors, in amounts much smaller than the global inventory. About one-third of this is released directly to the atmosphere, and the other two-thirds remains in the spent fuel. Both the Environmental Protection Agency and the Nuclear Regulatory Commission have established limits on release of the 14C in spent fuel. This is of particular concern for the proposed repository in tuff, because of the unsaturated conditions and the consequent possibility of gaseous tansport of 14C as CO2Existing measurements and calculations of the 14C inventory in spent fuel are reviewed. The physical distribution and Wemical forms of the 14C are discussed. Available data on the release of 14C from spent fuel in aqueous solutions and in gaseous environments of air, nitrogen, and helium are reviewed. Projected N behavior in a tuff repository is described. It is concluded that 14C release measurements from spent fuel into moist air at temperatures both above and below the in situ boiling point of water as well as detailed transport calculations for the tuff geological environment will be needed to determine whether the IOCFR60 and 40CFR191 requirements can be met.

Yucca Mountain Project Status

2002 ◽  
Vol 757 ◽  
Author(s):  
Thomas E. Kiess ◽  
Stephen H. Hanauer
Keyword(s):  
Spent Nuclear Fuel ◽  
Nuclear Regulatory Commission ◽  
The United States ◽  
Yucca Mountain ◽  
Department Of Energy ◽  
Geologic Repository ◽  
Regulatory Standard ◽  
Regulatory Commission ◽  
High Level ◽  
The U.S

ABSTRACTThe Yucca Mountain site was designated in July 2002 as the United States' location for a geological repository for spent nuclear fuel and other high-level radioactive wastes. This site designation was a watershed event in the history of the project, enabling the U.S. Department of Energy to seek a license from the U.S. Nuclear Regulatory Commission to construct and operate a geologic repository. Summarized below are the history and technical basis for this site designation and some key anticipated future events. Many of the significant events to date have been framed by the Nuclear Waste Policy Act (and Amendments) and the requirements of the regulatory standard.

scholarly journals Seismic Analysis Issues in Design Certification Applications for New Reactors

2011 ◽  
Author(s):  
Richard Morante ◽  
Manuel Miranda ◽  
Jim Xu
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Seismic Analysis ◽  
Nuclear Regulatory Commission ◽  
Design Parameters ◽  
Specific Design ◽  
Site Specific ◽  
Safety Issues ◽  
Standard Design ◽  
Regulatory Commission

The licensing framework established by the U.S. Nuclear Regulatory Commission under Title 10 of the Code of Federal Regulations (10 CFR) Part 52, “Licenses, Certifications, and Approvals for Nuclear Power Plants,” provides requirements for standard design certifications (DCs) and combined license (COL) applications. The intent of this process is the early resolution of safety issues at the DC application stage. Subsequent COL applications may incorporate a DC by reference. Thus, the COL review will not reconsider safety issues resolved during the DC process. However, a COL application that incorporates a DC by reference must demonstrate that relevant site-specific design parameters are within the bounds postulated by the DC, and any departures from the DC need to be justified. This paper provides an overview of several seismic analysis issues encountered during a review of recent DC applications under the 10 CFR Part 52 process, in which the authors have participated as part of the safety review effort.

Regulatory experience in applying a radiological environmental protection framework for existing and planned nuclear facilities

2012 ◽  
Vol 41 (3-4) ◽  
pp. 256-262 ◽  
Author(s):  
S. Mihok ◽  
P. Thompson
Keyword(s):  
Environmental Protection ◽  
Environmental Protection Agency ◽  
Nuclear Regulatory Commission ◽  
Nuclear Safety ◽  
Department Of Energy ◽  
Dose Assessment ◽  
Radiological Protection ◽  
Nuclear Facilities ◽  
Legal Requirements ◽  
Energy Agency

Frameworks and methods for the radiological protection of non-human biota have been evolving rapidly at the International Commission on Radiological Protection and through various European initiatives. The International Atomic Energy Agency has incorporated a requirement for environmental protection in the latest revision of its Basic Safety Standards. In Canada, the Canadian Nuclear Safety Commission has been legally obligated to prevent unreasonable risk to the environment since 2000. Licensees have therefore been meeting generic legal requirements to demonstrate adequate control of releases of radioactive substances for the protection of both people and biota for many years. In the USA, in addition to the generic requirements of the Environmental Protection Agency and the Nuclear Regulatory Commission, Department of Energy facilities have also had to comply with specific dose limits after a standard assessment methodology was finalised in 2002. Canadian regulators developed a similar framework for biota dose assessment through a regulatory assessment under the Canadian Environmental Protection Act in the late 1990s. Since then, this framework has been applied extensively to satisfy legal requirements under the Canadian Environmental Assessment Act and the Nuclear Safety and Control Act. After approximately a decade of experience in applying these methods, it is clear that simple methods are fit for purpose, and can be used for making regulatory decisions for existing and planned nuclear facilities.

scholarly journals Analysis of the Technological Evolution of Materials Requirements Included in Reactor Pressure Vessel Manufacturing Codes

2021 ◽  
Vol 13 (10) ◽  
pp. 5498
Author(s):  
Alvaro Rodríguez-Prieto ◽  
Mariaenrica Frigione ◽  
John Kickhofel ◽  
Ana M. Camacho
Keyword(s):  
Sustainable Development ◽  
Pressure Vessel ◽  
Nuclear Regulatory Commission ◽  
Green Energy ◽  
Reactor Pressure Vessel ◽  
Technical Literature ◽  
Pressurized Water ◽  
Water Reactors ◽  
Regulatory Commission ◽  
Reactor Pressure

The growth of green energy technologies within the frame of the 7th Sustainable Development Goal (SDG) along with the concern about climatic changes make nuclear energy an attractive choice for many countries to ensure energy security and sustainable development as well as to actively address environmental issues. Unlike nuclear equipment (immovable goods), which are often well-catalogued and analyzed, the design and manufacturing codes and their standardized materials specifications can be considered movable and intangible goods that have not been thoroughly studied based on a detailed evaluation of the scientific and technical literature on the reactor pressure vessel (RPV) materials behavior. The aim of this work is the analysis of historical advances in materials properties research and associated standardized design codes requirements. The analysis, based on the consolidated U.S. Nuclear Regulatory Commission (NRC) Regulatory Guide (RG) 1.99 Rev.2 model, enables determination of the best materials options, corresponding to some of the most widely used material specifications such as WWER 15Kh2MFAA (used from the 1970s and 1980s; already in operation), ASME SA-533 Grade B Cl.1 (used in pressurized water reactor-PWR 2nd–4th; already in operation), DIN 20MnMoNi55 and DIN 22NiMoCr37 (used in PWR 2nd–4th) as well as ASTM A-336 Grade F22V (current designs). Consequently, in view of the results obtained, it can be concluded that the best options correspond to recently developed or well-established specifications used in the design of pressurized water reactors. These assessments endorse the fact that nuclear technology is continually improving, with safety being its fundamental pillar. In the future, further research related to the technical heritage from the evolution of materials requirements for other clean and sustainable power generation technologies will be performed.

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