[en] The purposes of the Borehold Plugging Program are: to identify issues associated with sealing boreholes and shafts; to establish a data base from which to assess the importance of these issues; and to develop sealing criteria, materials, and demonstrative test for the Waste Isolation Pilot Plant (WIPP). The Bell Canyon Test described in this report is one part of that program. Its purpose was to evaluate, in situ, the state of the art in borehole plugs and to identify and resolve problems encountered in evaluating a typical plug installation in anhydrite. The test results are summarized from the work of Peterson and Christensen and divided into two portions: system integrity and wellbore characterization tests prior to plug installation, and a series of tests to evaluate isolation characteristics of the 1.8-m-long plug. Conclusions of the Bell Canyon Test are: brine and fresh-water grouts, with acceptable physical properties in the fluid and hardened states, have been developed; the field data, taken together with laboratory data, suggest that the predominant flow into the test region occurs through the cement plug/borehold interface region, with lesser contributions occurring through the wellbore damage zone, the plug core, and the surrounding undisturbed anhydrite bed; and the 1.8-m-long by 20-cm-diameter grout plug, installed in anhydrite at a depth of 1370 m in the AEC-7 borehole, limits flow from the high pressure Bell Canyon aquifer to 0.6 liters/day

[en] The report reviews the geologic and hydrologic data base for penetration seal designs referenced to the Los Medanos bedded salt site in New Mexico and to four candidate salt domes in the Gulf Interior. Experience with existing shafts highlights the importance, for shaft decommissioning as well as operation, of achieving an adequate seal at and immediately below the top of salt. Possible construction procedures for repository shafts are reviewed, noting advantages and disadvantages with respect to repository sealing. At this stage, there does not appear to be a clear preference for excavation by drill and blast or by drilling. If conventional drill and blast methods are used, it may be necessary to grout in permeable zones above the salt. An important consideration with respect to sealing is that grouting operations (or freezing should it be used) should not establish connections between the top of salt and water-bearing zones higher in the stratigraphic section. Generally, it is concluded that Los Medanos and the dome salt sites are favorable candidate repository sites from the point of view of sealing

[en] The Canadian research program to investigate the disposal of nuclear fuel waste is well established with participation from a wide cross section of the scientific and engineering community. Some phases of the program have not proceeded at the pace originally envisaged. Nevertheless, significant progress has been made. The resources available and difficulties in obtaining approval for additional field research areas have restricted geotechnical research to granite formations. With the prospect of increased levels of funding and new initiatives for approvals for field research, it is expected that the program will proceed on a broader front

[en] Safe deposition of radioactive canisters in boreholes or tunnels requires a buffer mass for which the following criteria are specified: sufficient bearing capacity, suitable plastic mechnical properties, low permeability, ion-adsorption ability, sufficiently good heat conduction. Its required physical and mechanical properties must also be stable for thousands of years at the elevated temperature in the radiation field close to the canisters. So for all evidence given in the current investigation shows that a combination of Na-bentonite and silt/sand-sized quartz components gives a buffer mass with optimum properties. The bentonite should form at least 10 weight percent of the solid mass where the bearing capacity is important. In other parts of the bore-holes, tunnels and shafts the bentonite content can be increased to 20 or even higher percentages

[en] A thermoelastic/plastic finite element analysis of the influence of an air-gap on hole closure about a waste-container/sleeve assembly emplaced in a typical repository room (SALT/4T Model) indicates that hole closure would be of the order of hundredths of an inch. Acceptable air-gap width is thus governed by the hole size required for emplacement efficiency. A refined mesh analysis and laboratory testing is suggested in order to further explore the possibility of eliminating the engineering necessity of the sleeve

[en] The five major chemical processes, the Bismuth Phosphate process, the Uranium Recovery process, the Redox process, the Purex process, and the Waste Fractionization process have each contributed to give the total Hanford waste chemicals. Each of these processes is studied to determine the total estimated chemicals stored in underground waste tanks. The chemical contents are derived mainly from flowsheet compositions and recorded waste volumes sent to underground storage. The major components and amounts of Hanford waste are sodium hydroxide, 230 million gram-moles (20 million pounds), sodium nitrate, 1400 million gram-moles (270 million pounds), sodium nitrite, 220 million gram-moles (34 million pounds), sodium aluminate, 400 million gram-moles (72 million pounds), and sodium phosphate, 87 million gram-moles (31 million pounds). Chemical analyses of the sludge and salt cake samples are tabulated to determine the chemical characteristics of the solids. A relative chemical toxicity of the Hanford underground waste tank chemicals is developed from maximum permissible chemical concentrations in air and water. The most toxic chemicals are assumed to be sodium phosphate--35%, sodium aluminate--28%, and chromium hydroxide--19%. If air standards set toxicity limits, the most toxic chemicals are bismuth--41%, chromium hydroxide--23%, and fluoride--10%

[en] The present study is devoted to the problems associated with disposal of radioactive waste in the Swedish crust. Recent investigations seem to indicate that the present uplift in Fennoscandia is no longer of isostatic origin. A tectonic factor has been detected and this component is supposed to dominate the uplift now recorded. The total uplift of the Swedish east-coast is 1,4-12 mm per year from south to north. The main object has been to discriminate between tectonic and isostatic movements. There has been practically no proof for the existence of a major tectonic movement in the Fennoscandian crust. The tectonic uplift is estimated to be below 1 mm per year. The problem of the optimated choice of a site for waste disposal inside the Swedish crust is very intricate and must be considered from a number of different points of view. (L.B.)

[en] This paper presents the current Borehole Plugging Program (BHP) at Sandia National Laboratories and addresses the four major functional tasks considered necessary for a successful program: (1) project management, including methods to identify, design, and control needed experimentation; (2) identification of candidate materials, emphasizing cement-based products as the most advanced alternatives due to the extensive existing technology base, but recognizing the potential application of alternate materials; (3) development of test instrumentation based on utilization of existing techniques, evaluation of their adequacy, and identifying modifications necessary to improve effectiveness; (4) field test program, which includes testing and verification of plug performance. The scope of the current program on wellbores, cementitious grouts, and available technology is compared to planned extension to shafts and drifts, alternate materials, and improved instrumentation. The relationship of this program with assessments of long-term suitability performed in the geochemical program is presented. A brief presentation of current and planned field tests is given along with projections for future activities and results

[en] Room and pillar deformation were measured in conjunction with a relatively new type of mining operation in a southeastern New Mexico potash mine. The extraction ration was approximately 90 percent in a first mining operation. Due to severe deformations encountered, instrumentation had to be developed/modified for these measurements. This paper concentrates on experiment design, design of special instrumentation, field installation of equipment, and presentation of the data. Measurements made include extensometers in the pillar, in the floor and ceiling in the room between pillars, absolute level measurements, floor ceiling closure, and stress (strain) measurements. Associated laboratory rock mechanics measurements of samples from the mine are being done separately. Two separate room pillar complexes were instrumented. In the first complex, floor-ceiling deformations of approximately 1 inch/day and pillar deformations around 1/2 inch/day were measured. In the second complex, instrumentation was installed while the pillar was a part of a long wall and the subsequent sequential mining (long wall-pillar with only one adjoining room on one side - pillar in the middle of room pillar complex) was observed. Data return from this operation was good

[en] The processing of irradiated nuclear fuels at the Department of Energy's (DOE) Hanford Site produced large volumes of radioactive liquid waste. Some of this waste was disposed to the sediments underlying the Hanford Site by means of disposal facilities called reverse wells. One such facility is the 216-B-5 reverse well. This reverse well was one of the first disposal sites used at Hanford, and was in service from 1945 to 1947. An investigation of the 216-B-5 reverse well was conducted during 1979 and 1980. Wells were drilled around the reverse well and sediment samples were collected and analyzed in order to determine the spatial distribution of radionuclides sorbed on the sediments. These analyses were then used to map distributions of ²³⁹²⁴⁰Pu, ¹³⁷Cs, and ⁹⁰Sr around the reverse well. The impact of the sorbed radionuclides on ground-water contamination was considered