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Title: DRSPALL :spallings model for the Waste Isolation Pilot Plant 2004 recertification.

Abstract

This report presents a model to estimate the spallings releases for the Waste Isolation Pilot Plant Performance Assessment (WIPP PA). A spallings release in the context of WIPP PA refers to a portion of the solid waste transported from the subsurface repository to the ground surface due to inadvertent oil or gas drilling into the WIPP repository at some time after site closure. Some solid waste will be removed by the action of the drillbit and drilling fluid; this waste is referred to as cuttings and cavings. If the repository is pressurized above hydrostatic at the time of intrusion, solid waste material local to the borehole may be subject to mechanical failure and entrainment in high-velocity gases as the repository pressure is released to the borehole. Solid material that fails and is transported into the wellbore and thus to the surface comprise the spallings releases. The spallings mechanism is analogous to a well blowout in the modern oil and gas drilling industry. The current spallings conceptual model and associated computer code, DRSPALL, were developed for the 2004 recertification because the prior spallings model used in the 1996 WIPP Compliance Certification Application (CCA) was judged by an independent peer review panelmore » as inadequate (DOE 1996, 9.3.1). The current conceptual model for spallings addresses processes that take place several minutes before and after a borehole intrusion of a WIPP waste room. The model couples a pipe-flow wellbore model with a porous flow repository model, allowing high-pressure gas to flow from the repository to the wellbore through a growing cavity region at the well bottom. An elastic stress model is applied to the porous solid domain that allows for mechanical failure of repository solids if local tensile stress exceeds the tensile strength of the waste. Tensile-failed solids may be entrained into the wellbore flow stream by a fluidized bed model, in which case they are ultimately transported to the land surface comprising a release. In July 2003, DOE/SNL presented the spallings conceptual model to a independent peer review panel in accordance with NUREG 1297 guidelines (NRC, 1988). The panel ultimately judged the model as adequate for implementation in WIPP PA (Yew et al., 2003). This report documents the spallings model history from 1997 to the implementation of DRSPALL in the 2004 Compliance Recertification Application (CRA) (DOE, 2004). The scope of this report includes descriptions of the conceptual model, numerical model, verification and validation techniques, model sensitivity studies, and WIPP PA spallings results as presented in the 2004 CRA.« less

Authors:
 [1]; ;  [2];  [3];
  1. (GRAM Inc., Albuquerque, NM)
  2. (John F. Schatz Research & Consulting, Inc., Del Mar, CA)
  3. (GRAM Inc., Albuquerque, NM)
Publication Date:
Research Org.:
Sandia National Laboratories
Sponsoring Org.:
USDOE
OSTI Identifier:
883469
Report Number(s):
SAND2004-0730
TRN: US0603448
DOE Contract Number:
AC04-94AL85000
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
12 MANAGEMENT OF RADIOACTIVE WASTES, AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES; BLOWOUTS; BOREHOLES; COMPLIANCE; COMPUTER CODES; DRILLING; DRILLING FLUIDS; ENTRAINMENT; FLUIDIZED BEDS; GASES; HYDROSTATICS; IMPLEMENTATION; SENSITIVITY; SOLID WASTES; TENSILE PROPERTIES; VALIDATION; VERIFICATION; WASTES; WIPP; Spalling.; Waste Isolation Pilot Plant (N.M; Solid waste.

Citation Formats

Gilkey, Amy P., Hansen, Clifford W., Schatz, John F., Rudeen, David Keith, and Lord, David L.. DRSPALL :spallings model for the Waste Isolation Pilot Plant 2004 recertification.. United States: N. p., 2006. Web. doi:10.2172/883469.
Gilkey, Amy P., Hansen, Clifford W., Schatz, John F., Rudeen, David Keith, & Lord, David L.. DRSPALL :spallings model for the Waste Isolation Pilot Plant 2004 recertification.. United States. doi:10.2172/883469.
Gilkey, Amy P., Hansen, Clifford W., Schatz, John F., Rudeen, David Keith, and Lord, David L.. Wed . "DRSPALL :spallings model for the Waste Isolation Pilot Plant 2004 recertification.". United States. doi:10.2172/883469. https://www.osti.gov/servlets/purl/883469.
@article{osti_883469,
title = {DRSPALL :spallings model for the Waste Isolation Pilot Plant 2004 recertification.},
author = {Gilkey, Amy P. and Hansen, Clifford W. and Schatz, John F. and Rudeen, David Keith and Lord, David L.},
abstractNote = {This report presents a model to estimate the spallings releases for the Waste Isolation Pilot Plant Performance Assessment (WIPP PA). A spallings release in the context of WIPP PA refers to a portion of the solid waste transported from the subsurface repository to the ground surface due to inadvertent oil or gas drilling into the WIPP repository at some time after site closure. Some solid waste will be removed by the action of the drillbit and drilling fluid; this waste is referred to as cuttings and cavings. If the repository is pressurized above hydrostatic at the time of intrusion, solid waste material local to the borehole may be subject to mechanical failure and entrainment in high-velocity gases as the repository pressure is released to the borehole. Solid material that fails and is transported into the wellbore and thus to the surface comprise the spallings releases. The spallings mechanism is analogous to a well blowout in the modern oil and gas drilling industry. The current spallings conceptual model and associated computer code, DRSPALL, were developed for the 2004 recertification because the prior spallings model used in the 1996 WIPP Compliance Certification Application (CCA) was judged by an independent peer review panel as inadequate (DOE 1996, 9.3.1). The current conceptual model for spallings addresses processes that take place several minutes before and after a borehole intrusion of a WIPP waste room. The model couples a pipe-flow wellbore model with a porous flow repository model, allowing high-pressure gas to flow from the repository to the wellbore through a growing cavity region at the well bottom. An elastic stress model is applied to the porous solid domain that allows for mechanical failure of repository solids if local tensile stress exceeds the tensile strength of the waste. Tensile-failed solids may be entrained into the wellbore flow stream by a fluidized bed model, in which case they are ultimately transported to the land surface comprising a release. In July 2003, DOE/SNL presented the spallings conceptual model to a independent peer review panel in accordance with NUREG 1297 guidelines (NRC, 1988). The panel ultimately judged the model as adequate for implementation in WIPP PA (Yew et al., 2003). This report documents the spallings model history from 1997 to the implementation of DRSPALL in the 2004 Compliance Recertification Application (CRA) (DOE, 2004). The scope of this report includes descriptions of the conceptual model, numerical model, verification and validation techniques, model sensitivity studies, and WIPP PA spallings results as presented in the 2004 CRA.},
doi = {10.2172/883469},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Wed Feb 01 00:00:00 EST 2006},
month = {Wed Feb 01 00:00:00 EST 2006}
}

Technical Report:

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  • The numerical code DRSPALL (from direct release spallings) is written to calculate the volume of Waste Isolation Pilot Plant (WIPP) solid waste subject to material failure and transport to the surface as a result of a hypothetical future inadvertent drilling intrusion. An error in the implementation of the DRSPALL finite difference equations was discovered as documented in Software Problem Report (SPR) 13-001. The modifications to DRSPALL to correct the finite difference equations are detailed, and verification and validation testing has been completed for the modified DRSPALL code. The complementary cumulative distribution function (CCDF) of spallings releases obtained using the modifiedmore » DRSPALL is higher compared to that found in previous WIPP performance assessment (PA) calculations. Compared to previous PAs, there was an increase in the number of vectors that result in a nonzero spallings volume, which generally translates to an increase in spallings releases. The overall mean CCDFs for total releases using the modified DRSPALL are virtually unchanged, thus the modification to DRSPALL did not impact WIPP PA calculation results.« less
  • No abstract prepared.
  • This Geotechnical Analysis Report (GAR) presents and interprets the geotechnical data from the underground excavations at the Waste Isolation Pilot Plant (WIPP). The data, which are obtained as part of a regular monitoring program, are used to characterize conditions, to compare actual performance to the design assumptions, and to evaluate and forecast the performance of the underground excavations. GARs have been available to the public since 1983. During the Site and Preliminary Design Validation (SPDV) Program, the architect/engineer for the project produced these reports quarterly to document the geomechanical performance during and immediately after early excavations of the underground facility.more » Since the completion of the construction phase of the project in 1987, the management and operating contractor for the facility has prepared these reports annually. This report describes the performance and condition of selected areas from July 1, 2004, to June 30, 2005. It is divided into nine chapters. Chapter 1 provides background information on WIPP, its mission, and the purpose and scope of the Geomechanical Monitoring Program. Chapter 2 describes the local and regional geology of the WIPP site. Chapters 3 and 4 describe the geomechanical instrumentation in the shafts and shaft stations, present the data collected by that instrumentation, and provide interpretation of these data. Chapters 5 and 6 present the results of geomechanical monitoring in the two main portions of the WIPP underground (the access drifts and the waste disposal area). Chapter 7 discusses the results of the Geoscience Program, which include fracture mapping and borehole observations. Chapter 8 summarizes the results of the geomechanical monitoring and compares the current excavation performance to the design requirements. Chapter 9 lists the references and bibliography.« less
  • Pretest 3-D finite element calculations have been performed on the wedge pillar portion of the WIPP Geomechanical Evaluation Experiment. The wedge pillar separates two drifts that intersect at an angle of 7.5/sup 0/. Purpose of the experiment is to provide data on the creep behavior of the wedge and progressive failure at the tip. The first set of calculations utilized a symmetry plane on the center-line of the wedge which allowed treatment of the entire configuration by modeling half of the geometry. Two 3-D calculations in this first set were performed with different drift widths to study the influence ofmore » drift size on closure and maximum stress. A cross-section perpendicular to the wedge was also analyzed with 2-D finite element models and the results compared to the 3-D results. In another set of 3-D calculations both drifts were modeled but with less distance between the drifts and the outer boundaries. Results of these calculations are compared with results from the other calculations to better understand the influence of boundary conditions.« less
  • The following topics related to the treatment of cuttings, cavings and spallings releases to the surface environment in the 1996 performance assessment for the Waste Isolation Pilot Plant (WIPP) are presented: (1) mathematical description of models. (2) uncertainty and sensitivity analysis results arising from subjective (i.e., epistemic) uncertainty for individual releases, (3) construction of complementary cumulative distribution functions (CCDFs) arising from stochastic (i.e., aleatory) uncertainty, and (4) uncertainty and sensitivity analysis results for CCDFs. The presented results indicate that direct releases due to cuttings, cavings and spallings do not constitute a serious threat to the effectiveness of the WIPP asmore » a disposal facility for transuranic waste. Even when the effects of uncertain analysis inputs are taken into account, the CCDFs for cuttings, cavings and spallings releases fall substantially to the left of the boundary line specified in the US Environmental Protection Agency standard for the geologic disposal of radioactive waste (40 CFR 191, 40 CFR 194).« less