A salt cavern abandonment test

Uncertainty and sensitivity analysis results obtained in the 1992 performance assessment for the waste isolation pilot plant

This document provides an overview of the process used to assess the performance of the Waste Isolation Pilot Plant (WIPP), a proposed repository for transuranic wastes that is located in southeastern New Mexico. The quantitative metrics used in the performance-assessment (PA) process are those put forward in the Environmental Protection Agency`s Environmental Standards for the Management and Disposal of Spent Nuclear Fuel, High-Level and Transuranic Radioactive flasks (40 CFR 191). Much has been written about the individual building blocks that comprise the foundation of PA theory and practice, and that WIPP literature is well cited herein. However, the present approach is to provide an accurate, well documented overview of the process, from the perspective of the mechanical steps used to perform the actual PA calculations. Specifically, the preliminary stochastic simulations that comprise the WIPP PAs of 1990, 1991. and 1992 are summarized.

/pdf/an-introduction-to-the-mechanics-of-performance-assessment-5bu3ayeyea.pdf

An introduction to the mechanics of performance assessment using examples of calculations done for the Waste Isolation Pilot Plant between 1990 and 1992

Assignment of probability distributions for parameters in the 1996 performance assessment for the Waste Isolation Pilot Plant. Part 1: description of process

The Small-Scale Mine-By was an in situ experiment to measure changes in brine and gas permeability of rock salt as a result of nearby excavation. A series of small-volume pressurized brine- and gas-filled test intervals were established 8 m beneath the floor of Room L1 in the WIPP underground. The test intervals were isolated in the bottom of the 4.8-cm diameter monitoring boreholes with inflatable rubber packers, and are initially pressurized to about 2 MPa. Both brine- and gas-filled test intervals were located 1.25, 1.5, 2, 3, and 4 r from the center of a planned large-diameter hole, where r is the radius of the large-diameter hole. Prior to the drilling of the large-diameter borehole, the responses of both the brine- and gas-filled test intervals were consistent with the formation modeled as a very low permeability, low porosity porous medium with a significant pore (brine) pressure and no measurable gas permeability. The drilling of the mine-by borehole created a zone of dilated, partially saturated rock out to about 1.5 r. The formation pressure increases from near zero at 1.5 r to the pre-excavation value at 4 r. Injection tests reveal a gradient of brine permeabilities from 5 {times} 10{sup {minus}18}more » m{sup 2} at 1.25 r to about the pre-excavation value (10{sup {minus}21} m{sup 2}) by 3 r. Gas-injection tests reveal measurable gas permeability is limited to within 1.5 r. 17 refs., 24 figs., 6 tabs.« less

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In situ measurements of rock salt permeability changes due to nearby excavation

/pdf/interpretation-of-in-situ-pressure-and-flow-measurements-of-5cq9zulqme.pdf

E.J. Nowak

Papers

Interpretation of In-Situ Pressure and Flow Measurements of the Salado Formation at the Waste Isolation Pilot Plant