[en] This report describes the Licensing Support Network (LSN) Assistant--a set of tools for categorizing e-mail messages and documents, and investigating and correcting existing archives of categorized e-mail messages and documents. The two main tools in the LSN Assistant are the LSN Archive Assistant (LSNAA) tool for recategorizing manually labeled e-mail messages and documents and the LSN Realtime Assistant (LSNRA) tool for categorizing new e-mail messages and documents. This report focuses on the LSNAA tool. There are two main components of the LSNAA tool. The first is the Sandia Categorization Framework, which is responsible for providing categorizations for documents in an archive and storing them in an appropriate Categorization Database. The second is the actual user interface, which primarily interacts with the Categorization Database, providing a way for finding and correcting categorizations errors in the database. A procedure for applying the LSNAA tool and an example use case of the LSNAA tool applied to a set of e-mail messages are provided. Performance results of the categorization model designed for this example use case are presented

[en] Volcanic tuffs under Yucca Mountain on the Nevada Test Site (NTS) are being considered as potential media for geologic disposal of radioactive waste. Calculations in support of site evaluation, repository design, and performance assessment require accurate estimates of the in situ stresses and the variability in the stress state within Yucca Mountain. This paper uses the regional geologic studies that pertain to the stress state at the NTS, stress measurements at Yucca Mountain, and stress measurements in nearby Rainier Mesa, in conjunction with finite element calculations to estimate the in situ stresses at Yucca Mountain. Based on these data, values of lateral earth-stress coefficients (K₀) in the range 0.3 < K₀ < 0.8 are reasonable for repository depths in thermomechanical analyses. 5 figs

[en] Our study extends the petrographic zonation of the devitrified rhyolitic tuff matrix of the Topopah Spring Member of the Paintbrush Tuff observed in USW G-4 to four other cored holes in the Yucca Mountain area of the Nevada Test Site: UE-25a No. 1, USW G-1, USW G-2, and USW GU-3. The four petrographic zones occur above the basal vitrophyre and in ascending order are the lower nonlithophysal (ln); the lower lithophysal (ll); the middle nonlithophysal (mn); and the upper lithophysal (ul). Drill hole USW G-2, about two miles north of the Yucca Mountain Exploratory Block, differs significantly from the other four cored holes within or near the block; it has essentially one thick microlitic zone, largely lithophysal, above the vitrophyre. Textural attributes (from coarsest to finest) are phenocrysts, lithics, granophyre, amygdules, spherulites, and cryptocrystalline groundmass. Among individual phenocrysts, only quartz shows significant decrease upward. The four petrographic zones agree fairly well with those defined by contacts placed by USGS geologists and, with minor reservations, can be correlated between the four cored holes in the vicinity of the exploration block. The ln zone is characterized by dense welding, upwardly decreasing cryptocrystallinity, common lithics, and quartz phenocrysts. The ll zone is largely spherulitic with 1 to 13% granophyre generally increasing upward and shard texture becoming less distinct upward. The mn zone is similar to the ln zone except for the moderate welding and fewer quartz and lithic fragments present in the mn zone. The ul and ll zones are similar in microscopic texture, but the ul has more amygdules with tridymite rather than cristobalite and can generally be recognized by its ''Swiss cheese'' appearance in core or hand specimens. A series of discriminatory statistical analyses were made with the thin section modal data to test variation in textural type and quartz phenocrysts

[en] K-Ar and ⁴⁰Ar/³⁹Ar ages from the Lathrop Wells volcanic center, Nevada, and from the Cima volcanic field, California, indicate that the recently reported 20-ka age estimate for the Lathrop Wells volcanic center is incorrect. Instead an age of 119±11 to 141±10 ka is indicated for the Lathrop Wells volcanic center. This age corrected is concordant with the ages determined by two independent isotopic geochronometric techniques and with the stratigraphy of surficial deposits in the Yucca Mountain region. In addition, paleomagnetic data and radiometric age data indicate only two volcanic events at the Lathrop Wells volcanic center that are probably closely linked in time, not as many as five as recently reported

[en] Computer-assisted geological cross section balancing methods are used in the geometric and kinematic analysis of subsurface structures in the vicinity of Yucca Mountain, Nevada, including underlying listric normal fault and detachment fault geometries and their relationships in a linked fault system. Dips of hanging wall fault blocks are directly related to the shapes of underlying curved normal and detachment faults. Arrays of small faults that are pervasively distributed through the hanging wall blocks are interpreted to be the bulk deformation mechanism of the block. As the hanging wall slides over the underlying fault surface, the fault block deforms to accommodate itself to the shape of the fault. Distributed slip on the small fault array is assumed to accomplish this shape change. The deformation is modeled as general simple shear, such that changes in shape of the model fault blocks take place by distributed slip on uniformly oriented slip surfaces that are evenly spaced through the area of the block, replicating the behavior of a deck of cards. Computed listric normal fault trajectories and surface geologic data constrain the range of compatible depths to potential detachment fault zones below Yucca Mountain to between about 3.5 and 6 kilometers. This is at least 1 to 2 kilometers deeper than the contact between the base of the Tertiary volcanics and the Paleozoic section. Preliminary balanced versions of sections A-A' and B-B' of Scott and Bonk show that assumption of a vertical simple shear deformation mechanism for fault block distortion will produce geologically reasonable subsurface models of faulting

[en] This paper presents views on the role of the licensing engineer in the design process with specific emphasis on design reviews and the automated information management tools that support design reviews. The licensing engineer is seen as an important member of a design review team. The initial focus of the licensing engineer during design reviews is shown to be on ensuring that applicable regulatory requirements are addressed by the design. The utility of an automated tool, such as a commitments management system, to support regulatory requirements identification is discussed. The next responsibility of the licensing engineer is seen as verifying that regulatory requirements are transformed into measurable performance requirements. Performance requirements are shown to provide the basis for developing detailed design review criteria. Licensing engineer input during design reviews is discussed. This input is shown to be especially critical in cases where review findings may impact application of regulatory requirements. The use of automated tools in supporting design reviews is discussed. An information structure is proposed to support design reviews in a regulated environment. This information structure is shown to be useful to activities beyond design reviews. Incorporation of the proposed information structure into the Licensing Support System is proposed

[en] This paper describes the role of the quality assurance liaison, the responsibilities of this position, and the evolutionary changes in duties over the last six years. The role of the quality assurance liaison has had a very positive impact on the Los Alamos Yucca Mountain Site Characterization (YW) quality assurance program. Having both technical and quality assurance expertise, the quality assurance liaisons are able to facilitate communications with scientists on quality assurance issues and requirements, thereby generating greater productivity in scientific investigations. The quality assurance liaisons help ensure that the scientific community knows and implements existing requirements, is aware of new or changing regulations, and is able to conduct scientific work within Project requirements. The influence of the role of the quality assurance liaison can be measured by an overall improvement in attitude of the staff regarding quality assurance requirements and improved job performance, as well as a decrease in deficiencies identified during both internal and external audits and surveillances. This has resulted in a more effective implementation of quality assurance requirements

[en] Earthquake data for the calendar year 1980 are presented for earthquakes occurring within and adjacent to the southern Nevada seismograph network. Locations, magnitudes, and selected focal mechanisms for these events and events from prior years of network operation are presented and discussed in relation to the geologic framework of the region. The principal results are that (1) earthquakes concentrate in fault zones having a northeast orientation, (2) fault zones having a northwest orientation are quiescent or nearly so, and (3) no earthquakes have been detected closer than 12 km to the Yucca Mountain nuclear waste repository study area. 12 references, 13 figures

[en] A laboratory investigation has been carried out to determine the effects of elevated temperature and stress on the creep deformation of welded tuffs recovered from Busted Butte in the vicinity of Yucca Mountain, Nevada. Water saturated specimens of tuff from thermal/mechanical unit TSw2 were tested in creep at a confining pressure of 5.0 MPa, a pore pressure of 4.5 MPa, and temperatures of 25 and 250 C. At each stress level the load was held constant for a minimum of 2.5 x 10⁵ seconds and for as long as 1.8 x 10⁶ seconds. One specimen was tested at a single stress of 80 MPa and a temperature of 250 C. The sample failed after a short time. Subsequent experiments were initiated with an initial differential stress of 50 or 60 MPa; the stress was then increased in 10 MPa increments until failure. The data showed that creep deformation occurred in the form of time-dependent axial and radial strains, particularly beyond 90% of the unconfined, quasi-static fracture strength. There was little dilatancy associated with the deformation of the welded tuff at stresses below 90% of the fracture strength. Insufficient data have been collected in this preliminary study to determine the relationship between temperature, stress, creep deformation to failure, and total failure time at a fixed creep stress

[en] Lithostratigraphic relations within the Calico Hills Formation and Prow Pass Tuff (Crater Flat Group) were reconstructed from analysis of core samples and observation of outcrop exposures. The Calico Hills Formation is composed of five nonwelded pyroclastic units (each formed of one or more pyroclastic-flow deposits) that overlie an interval of bedded tuff and a basal volcaniclastic sandstone unit. The Prow Pass Tuff is divided into four pyroclastic units and an underlying interval of bedded tuff. The pyroclastic units of the Prow Pass Tuff are distinguished by the sizes and amounts of their pumice and lithic clasts and their degree of welding. Pyroclastic units of the Prow Pass Tuff are distinguished from those of the Calico Hills Formation by their phenocryst assemblage, chemical composition, and ubiquitous siltstone lithic clasts. Downhole resistivity tends to mirror the content of authigenic minerals, primarily zeolites, in both for-mations and may be useful for recognizing the vitric-zeolite boundary in the study area. Maps of zeolite distribution illustrate that the bedded tuff and basal sandstone units of the Calico Hills Formation are altered over a wider area than the pyroclastic units of both the Calico Hills Formation and the upper Prow Pass Tuff