The unprecedented time span of concern and consequent need to predict future geological evolution, coupled with the potential consequences of failure, dictate that geological characterizations prepared for nuclear waste repository evaluation be immensely complex. The complexity of such investigations can, however, be used to optimize the knowledge achieved by a synergistic interaction between the individual geological disciplines. Additionally, we view the use of "back analysis" of geological structures as an essential tool of the characterisation process, for example for the assessment of constitutive relationships applicable during long periods of time. Considering a sedimentary basin as an example of a geologic system to be characterised, the role of the stratigraphy/lithology and structural geology/tectonics disciplines are reviewed. Comments are included on the role of vertical crustal movements in intraplate environments, as a directly measurable and therefore readily appreciable facet of the evolution of geologic systems. The significance of vertical crustal movement upon strain energy changes is noted. The roles of state of stress and geomorphology/palaeoclimate are introduced and used to illustrate the use of interaction between disciplines to optimize the geological characterisation. INTRODUCTION Emplacement in a geological system is a favored solution to the alternative proposals for isolation of high level nuclear waste. Selection of a suitable site, repository design and safety assessment depend upon a characterisation of the geological system within which the waste is to be stored. It must be assumed that the quality and relevance of geological characterisations prepared for repository development will therefore be directly reflected in the subsequent performance of the repository. In general, all activities involved in the isolation of waste in the earth's crust depend upon the geological characterizations prepared for this purpose. Because of the potential consequences of failure of a waste isolation facility, it is assumed that the investment in geological exploration will be substantial and thus the evaluation of geological conditions will be detailed. This in itself means that such investigations will be complex. Additionally, however, the comprehension of the geological system which must be achieved by such investigations is unprecedented. The lack of precedence arises largely as a result of the vastly increased time scale of concern. Previous investigations for potentially hazardous facilities have been related to engineering lives of generally less than 10 2 years; the nature of the nuclear waste to be isolated is such that time spans of the order of 10 6 years are of concern. Thus, the geologist is rather abruptly faced with the change of perspective determined by a time scale which is increased by approximately 10 4 years. This means that the geologist must consider evolution of the geologic system during the life of the waste repository. Other reasons which influence the level of the characterisation to be achieved, and the difficulties in achieving such, include the need to minimize disturbance of the rock mass, to account for groundwater flow at a regional scale and to account for thermomechanical effects. However, it is the time scale of concern and the consequence of failure which primarily determine the complexity of the geologic characterisation, and the need to optimize investigation.

If the subsurface is to be used to the degree which it merits, it is necessary to integrate it into the planning process at a level corresponding to that of other kinds of construction. Consideration of the subsurface alternatives must take place at an overall and detail planning level and among those actually concerned. It is essential that basic information include sufficient data on geology and that the planners themselves are aware of the advantages and drawbacks of subsurface use. Society should not content itself with a passive supervisory roll but also actively stimulate considerations of subsurface use. This should not only involve planning and construction but also relevant legislation, information, research and training. A central institution for subsurface construction would seem to be required. INTRODUCTION When suitable conditions exist the use of subsurface space can be greatly advantageous both to the owner of the installation 1 and to society as a whole. There are good reasons to regard the use of subsurface space as a resource within the field of community planning comparable to, for example, buildings and roads. It is consequently of interest to study how society takes this resource into consideration. What measures are taken to encourage its beneficial use (and to avoid its misuse)? The Swedish Building Code is at present being reviewed. It is generally agreed that subsurface use should be taken into account, e.g. by obligatory examination for building permission. It is, however, being discussed to what extent society should be involved and what guidelines should direct the formulation of the law. These guidelines are ·of vital interest as they will also influence regulations and recommendations to come. What is said below are to be considered contributions to this discussion. Installation is, for the purpose of this paper, taken to mean underground installation. SOCIETY'S INVOLVEMENT IN UNDERGROUND CONSTRUCTION In Sweden few parties are involved in subsurface construction. A few central or municipal departments and a few industries are principals for by far the greater part of existing installations. Naturally, most of them are to be found in the largest towns. However, in some smaller towns, for example, Trollhattan, many installations are to be found, while in others with comparable conditions there are none at all. This is due to the level of familiarity with the technique. When familiar with the technique you are likely to take subsurface alternatives into consideration. This knowledge is well represented within a rather restricted circle of people, mainly professionals at the government departments mentioned as well as among contractors and consultants. The representatives of the consumers such as politicians, physical planners, other government departments, decision makers within industry and others, are generally poorly or not at all acquainted with the technique. Consequently, they are in a poor position when it comes to considering the subsurface alternative. So far, subsurface construction in Sweden has been astonishingly anonymous considering its importance. Central and municipal authorities have normally paid very little attention to subsurface projects, for instance, building permits are not normally required.

For the pre-planning of a metro system it is important to have a good knowledge of tile ground conditions. If unforeseen circumstances are discovered later it is often almost impossible to change the placement of stations and the route alignments. The metro system of Helsinki was therefore planned with a great accuracy already at an early stage and with the conditions of the rock, soil, groundwater and foundations of the buildings thoroughly investigated. Special maps showing these conditions were used at the pre-planning work. INTRODUCTION The first section of the Helsinki metro system will be inaugurated in 1982. The line will be 13 km long and include 9 stations and will link the city centre of Helsinki with one of its north eastern suburbs. The decision to build a metro system for the half a million inhabitants of the Finnish capital was taken in 1969. But before the detailed planning and construction work could begin, a comprehensive study had to be made to plan and select alternative routes. And it is this important pre-planning stage that is the subject of this paper. In principle the pre-planning stage can be divided into three main sections •See Fig. 1. The first includes the regional metro system and studies of alternative routes. In the second stage the various routes of established lines are studied. This is used to help select a route which will provide the best possible transport service for those parts of the city and urban areas that the new line will serve. At the third and final stage of preplanning, different routes are studied with a view to the technical demands involved. Alternative sites for ticket halls with exits leading to ground level are also studied. The placement of stations is analyzed as well as the type of stations, which is selected and adjusted according to the possibilities for the placement of ticket halls, the technical prerequisites for construction, line geometry, and so on. Without a doubt it is this third pre-planning stage that is the most important in the job of creating a new metro system. This is why we have chosen to give you a general breakdown of how the planning of several aspects of the new metro system in Helsinki has been carried out. THE REGIONAL METRO NE1WORK To be able to plan a regional metro system all general pre-conditions must be identified. This is largely a question of regional planning involving general estimates of the volume of traffic, population development etc. Demands concerning the environment and the technical standards of transportation required must also be made at this stage. When it comes to Helsinki many different alternative routes and branches have been discussed and analyzed. Figure 1 shows the two routes included in the plans for the metro system in Helsinki. PRELIMINARY ROUTES At the preliminary route planning the number of stations and their approximate sites are established. As it is the stations that involve the majority of the building costs in a metro system the distance between each one must be carefully calculated.

Mined-out space which meets certain conditions can effectively be used for archives. This paper describes the practical considerations necessary to convert a mine into a highly secure information storage and handling facility, based on the experience of the Iron Mountain Group in New York State. It includes data on warehousing, libraries, laboratory space, private vaults, and back-up computer services. It also stresses the need for self-contained power and water sources and the importance of facility design in minimizing the psychological effects of underground habitation. Economy is cited as a primary reason for going underground. INTRODUCTION Taking into consideration that most archives are to be used in perpetuity and most records are semi-active to inactive, mined-out space provides an excellent alternative to above ground warehousing. Using mined-out space allows an individual or corporation to take advantage of what could be considered fallow real estate and turn it into climate-controlled facilities with reduced construction and operating cost of both a fixed and variable nature. Coverage of some key elements should include location, cost, human factors, and future application. MINE LOCATION Although future technology may reduce the need for archives to be located near a major urban center, at today''s standards this is still important. A location within the radius of 200 miles is felt to be an ideal situation. As an example, the Iron Mountain Group, home office in Boston, Massachusetts, operates two underground facilities in New York State. One facility is in what used to be an iron core drift mine located near Hudson, New York, approximately 105 miles north of New York City. The second facility is a former limestone mine situated 80 miles north of, New York City. Each facility is also within 200 miles of Boston, Massachusetts. This allows both operations to draw from a large customer base in what is essentially the largest urban area in the Northeastern United States. MINE GEOLOGY Once the location is earmarked as prime, based on its proximity of large urban areas, we must evaluate the mines geological and physical characteristics as follows. Structural Stability Much of the information needed in this area can be gathered from the latest geological survey. If a survey is non-existent or is too old to insure dependability, steps should be taken to acquire this information. Our experience has shown that even though a facility looks sound and has been standing in sound condition for many years, extensive rock bolting, shotcreting, and drain work may be necessary to insure stability in a developing facility where environment or structural changes have occurred. Mine Description Much of this information can be gathered from the geological survey, if properly outlined and planned. Particular attention should be paid to the following. Contour, floor and ceiling. This is important to construction cost. A more evenly contoured opening will lessen the cost of backfilling, grading, and concrete work in the floor, ceiling, and walls. Room heights. To determine the type of building, its use and location within the facility, is room height.

The physical background for magnetic and VLF measurements and their response to fracture zones is shortly reviewed. The ability for the identification of fracture zones using a combined interpretation of magnetic and VLF measurements is then demonstrated with a number of cases and examples where both airborne and ground measurements are used. Attention is drawn to the necesstity of combining various regional geophysical methods in order to achieve a more complete coverage of information on fracture zones. It is concluded that the demonstrated methods give a powerful tool to localize and characterize fracture zones. INTRODUCTION A programme of systematic low altitude airborne measurements including magnetic total field and VLF measurements is run by the Geological Survey of Sweden. The programme is mainly financed by the ore prospecting and mapping budgets. The measurements are made at an altitude of 30 m above ground and with a line spacing of 200 m. Measurements are made at every 40 m along the flight lines. Figure 1 shows an index map on airborne measurements in Sweden. The possibilities to prognostic mapping of bedrock qualities (regarding fracturing) using a combination of the magnetic and electrical measurements, both in a regional and a more detailed scale, have been strongly increased in the light of the results from recent methodological studies. Part of this work has been carried out in connection with the Swedish radwaste geophysical programme. The experience from a large number of bedrock investigations for tunne1projecting, powerstation- and reactorsites, waterprospecting etc, has shown that valuable information is gained from different kinds of electrical methods and from magnetics. (Eriksson, 1974; Muellern and Eriksson. 1979). ELECTROMAGNETIC MEASUREMENTS Airborne electromagnetic measurements with ground follow up in the frequency range 10 - 30 kHz have proved to be very sensitive to water bearing zones, èven when these have a comparatively low resistivity contrast to surrounding rocks. The electrical measurements could be made in the near- or induction field, i.e. very near a fixed or moving transmitter (slingram, turam, etc). An other possibility are measurements in the radiation field far away from VLF radio transmitters generally used for submarine navigation. As water bearing fracture zones act as very weak electrical conductors, the indications caused by the near or induction field could be looked upon as mainly inductive phenomena. However indications caused by the radiation field from very distant VLF transmitters could be seen as mainly conductive phenomena. Thus the extending radio wave field causes currents within the bedrock which tend to concentrate in the weak conductors thereby reducing the current strength in the surrounding areas. Figure 2 shows typical VLF total field anomalies. Depending on measuring technique, measuring configuration or frequency, we will get different sensitivity for zones with different geometrical positions (strike and dip), thickness, length and depth. Different methods also have a varying sensitivity to disturbancies from conductive overburden (such as salty clay or salt water sediments) which sometimes mask the indications from the bedrock. Powerlines. te1ephonelines etc could also disturb the measurements. The results from VLF interpretation are collected on interpretation maps which show the position and character of various conducting zones.

Geological characterizations for nuclear waste repositories are without precedent in terms of scope and intended utilization. Furthermore, the time scale of concern is vast in comparison to those with which previous geological characterizations has been concerned. Geological evolution is to be expected during this time scale consequently, evaluation of future changes must be undertaken. The basis for such evaluation can only be obtained from the geological record. Examples of past changes are outlined and an approach to the use of past changes for evaluation of future change is noted. INTRODUCTION The main objective of geologic investigations for nuclear waste repository development is the acquisition and analysis of appropriate data to characterize'' a complex geological/geotechnical system. Input derived from this characterization is required by all activities comprising the process of development of a geologic repository for ultimate disposal. and, permanent isolation of nuclear waste. A geologic nuclear waste repository must satisfy two broad' objectives: isolate the waste from the biosphere for a sufficient time such that release to the biosphere poses- no hazard and, achieve compatibility of the mode of waste storage wi.th any retrieval criteria. ''1''fre, adequacy of the approach adopted to satisfy these objectives must be demonstrated to the general public by means of the licensing procedures. Although these Procedures are not well defined, and in most licensing processes non-technical judgments often prevail, the concept adopted as a guideline for preparation of a licensing application may be to show that, for It given issue: 1. we adequately understand it. 2. We can adequately measure/evaluate it, and 3. We can estimate its long-term effects. The term "adequately" is obviously the key to acceptance of any technical knowledge. Adequate is used to mean a level of understanding, measurement, or evaluation capability sufficient to gain acceptance by the scientific community The characterizations required are without precedent in term's of scope and intended utilization (design and licensing of a repository). Moreover, the time scales which are applicable to repository performance are vast in comparison to those with which previous geological characterizations have been concerned. THE REQUIREMENTS OF GEOLOGIC CHARACTERIZATIONS FOR WASTE REPOSITORY DEVELOPMENT Background Prior to the introduction of nuclear technology, geological characterizations intended for immediate technological consumption were relatively simple. The information provided was typically utilized in mineral/petroleum and civil engineering industries. The characterizations seldom involved a wide spectrum of earth-science disciplines and/or a large amount of effort and funds. The attention was focused exclusively on definition of the geologic status quo. This limited participation of earth-science technology was justified by the relatively minor socio-environmental consequences and social commitments resulting and/or associated with the activities of the sponsoring industries. The emergence of nuclear technology, together with its benefits, potential hazards, and by-products, dramatically changed the sophistication of the geological characterizations required. Input involving an in-depth characterization, from a wide spectrum of earth-science disciplines, became an integral and obligatory part of any application for a license to construct and operate a commercial nuclear facility (usually a nuclear power plant).

In Norway a number of underground openings have been excavated for storing of drinking water. Such rock cavern tanks are safe, invisible and easy to extend and maintain. With reasonable geological conditions they are cheaper than conventional concrete and steel tanks, when the required volume extends approx. 8.000 m 3 . A close cooperation between the consulting engineer and the engineering geologist is necessary for a successful result. The author's experience from such cooperation are outlined and typical examples of rock cavern tanks are described. INTRODUCTION During the last 10 - 15 years a number of underground openings have been excavated in the hard bedrock of Norway either as replacement for or as alternative to open reservoirs or concrete or steel tanks for storage of drinking water. A closed water tank, as is the rock cavern tank, has several advantages compared with the traditional open reservoirs. It is above all easier to keep undesired pollutions under control with a closed tank. In open reservoirs the drinking water is exposed to the influence of sunlight and pollutions from the air. Open reservoirs are also commonly situated in natural or artificial depressions and will therefore have a draining effect on the surrounding landscape. Especially if such reservoirs are placed close to populated areas, there is a danger that polluted surface water or groundwater may be drained into the drinking water. Today the health authorities in Norway will normally not accept open reservoirs for storage of drinking water. New drinking water systems will have to include closed tanks of some kind. Old schemes with open reservoirs will often have to be redesigned and reconstructed. FUNCTIONS AND LOCATION OF WATER TANKS The basic function of a water tank is to act as a storage buffer to cover the variations in the consumption and keep the water head stable. This makes it easier to operate the treatment plant and the pumps at constant capacities. It allows smaller dimensions of the main pipe lines and gives stable pressures. In addition the water tanks will act as emergency storage in case of fire or failure in the supply system. Small water tanks are normally single chamber tanks. If the total volume exceeds approx. 10.000 m 3 , the tanks are often made as double or even multiple chamber tanks. This allows one chamber to be emptied for cleaning and maintenance without interrupting of the water supply. A water tank should be situated at an elevation which gives a suitable water pressure in the consumption area. It is also preferable to locate the tank as close to the consumption area as possible. This is especially important if the capacity of the tank is designed to cover the variations in the daily consumption. Most water tanks in Norway have been freestanding structures made of conventional reinforced concrete or prestressed concrete. When double chambers have been necessary, either two separate structures have been made or two concentric chambers in one structure. To minimize the impact such concrete structures may have on the environment, they have been dug often to some extent into the ground or tried hidden away in other ways.

This paper discusses the current activity ann, in particular, the current research efforts in the area of earth sheltered building design, construction, and acceptance in the U.S. INTRODUCTION Interest in the use of earth sheltered buildings has expanded greatly in the past 6 years, and particularly in the last 2 years. Prior to 1973, there were only a few isolated earth sheltered houses and scattered commercial and institutional examples of underground buildings in the United States. These were mostly built for design aesthetics or environmental reasons. Since then the number of earth sheltered buildings and houses being built has increased very rapidly. Since earth sheltering is not yet a term that is universally understood, it would perhaps be well to further define the concept before embarking on a discussion of what research is currently underway in the field. In broad terms, earth sheltering uses the earth as a barrier and a moderator. The earth Moderates temperature extremes in the air, and moderates surface vibrations and airborne noise. It acts as a barrier to storm and wind effects, ultraviolet degradation, and an undesirable visual environment. It has a large thermal mass that can work well with an intermittent energy supply such as solar energy. The earth is also a natural element which supports vegetation and, hence, the other life processes on which we ultimately depend. Using the earth to shelter a house or building, then, is a means of providing a natural barrier to many undesirable climatic and man-made features of a particular area. The impact of the building on the surrounding environment will also be lessened, allowing more of the land's surface to remain in a natural state. Furthermore, and of particular importance at the present time, earth sheltering serves as a massive means of decreasing the dependence of the building on artificial methods of climate control derived from fossil fuel energy. Naturally, there are also some disadvantages to earth sheltered structures. These relate primarily to the heavier and stronger structure required, tile need for high quality waterproofing and insulation to combat exposure to ground moisture, and the need for a higher level of design and supervision in small scale construction. Although earth sheltered designs are not limited to any fixed definitions, it will perhaps be helpful to explain two of the basic layouts that are typical of earth sheltered construction. A typical design that is very appropriate for colder climates is the elevational design in which windows and openings are grouped on one side of the structure, with the remaining three sides and roof earth-covered. When the windows do face south, a maximum amount of passive solar heating can be achieved to combine with the low energy requirements of the structure. A courtyard or atrium design is quite common and is a very appropriate design for a flat site or a warm climate. The courtyard does not have to be totally enclosed. Using a U-shaped courtyard allows an easier transition and visual connection to the surrounding ground.

The paper discusses the energy-saving potential of earth-sheltered buildings and the U.S. Department of Energy's research, development and demonstration activities and plans regarding their commercialization. INTRODUCTION The subject of my presentation--earth-sheltered buildings--involves a happy intersection of a problem and a potential. The problem is well recognized--the scarcity of energy and its rising price. The problem requires that we undertake effective energy conservation programs. In the United States, fully 37 percent of the nation's energy is used in the residential and commercial building sector. This underscores the importance of U.S. building energy conservation programs. The potential is not so broadly recognized. It is the potential of earth-sheltered designs to reduce by up to 30 to 60 percent or more the energy required for the heating and cooling of buildings. The U.S. Department of Energy regards earth-sheltered buildings as the promising alternative it is considering in its innovative structures program. The Department has monitored earth-sheltered building trends, supported research, identified barriers to commercialization, disseminated information, and is applying earth-sheltered designs to one of its own new buildings. HISTORY The term, earth-sheltered buildings, has not been captured by a formal definition. A good working definition applies the term to buildings with earth protection for 50 percent or more of the area of their roofs and exterior walls. Few of the buildings are entirely underground. but all use the earth to improve their energy performance. The current interest in earth-sheltered buildings is simply the latest chapter in man's continuing struggle to adapt to his environment. The first chapter was the caves inhabited at the dawn of human history. A more elegant version are the homes found in Ajanta, India, that date back to the 5th and 6th Centuries, A.D. A few centuries later, refugees from a crumbling Roman Empire, carved houses into soft, cone-shaped rocks in Cappadocia, Turkey. The Tunisian atrium houses through the century have provided protection from that area's extreme heat. The sod houses of the pioneers of the American prairie were another practical application of earth-sheltered design to cope with severe weather conditions where other building materials were not easily available. A rebirth of interest in earth-sheltered buildings has occurred in the United States during the past two decades. It has been nurtured by various themes. In the early phase, fear of atomic war led to habitable fallout shelters. In the later 1960's and 1970's, the environmental movement led architects to create earth-sheltered designs that were in harmony with the natural environment. The energy-saving benefits of earth-sheltered designs have fanned the rapidly spreading interest in the last half of the 1970's. As director of the Minnesota Energy Agency from 1975 to 1979 when I joined the U.S. Department of Energy, I participated in Minnesota's leadership in the support of earth-sheltered buildings. In the past few years, a state-sponsored guidebook, "Energy Sheltered Housing Design," (Underground Space Center, 1978) has become a best seller, selling more than 100,000 copies. A map of earthsheltered buildings is speckled with activity in all parts of the country with concentrations in Minnesota, Wisconsin and Oklahoma (Vadnais, 1980).