TL: The Waste Isolation Pilot Plant SO: Greenpeace International (GP) DT: August 1992 Keywords: nuclear power waste disposal gp us new mexico technology military weapons problems doe transportation / This report describes the current situation at WIPP and discusses the information and concerns about the project in the light of the visit made on August 17th 1992 by Claire Greensfelder (GPUS), Antony Froggatt (GPI) and Phil Richardson (Geological Consultant to GPI). Introduction WIPP, in New Mexico, has been constructed for the disposal of drummed TRU waste in bedded salt. It is intended to dispose of only those wastes currently in retrievable storage or newly generated. Any wastes generated pre-1970 are excluded. Originally intended as a pilot facility for commercial and high level waste disposal, it has been a planned site for military TRU waste only, since 1979. As a DOE site it is not subject to NRC licensing, but DOE have agreed that it should be subject to EPA standards (not yet formulated). To date, some 10 miles of tunnels have been excavated. The rooms originally planned for the test phase, (in the SPDV area, see below), cannot now be used, due to unpredictable roof and floor convergence. So far, 800,000 tons of salt have been excavated, and are currently stored on the surface. Up to 1,600,000 tons of additional salt will be excavated during the life of the repository. The project is supervised by DOE, with Westinghouse as main operators. Scientific coverage is provided by Sandia. At present, approx 120 people work underground. The total site complement is 1000, of whom 800 are from Westinghouse. 1400 people are associated with work for WIPP, including about 85 from Sandia. DOE funds an independent Environment Evaluation Group of 15, nominated by the State of New Mexico. Cost of the project so far is about $1 billion, with a 1992 budget of $165 million. There are 2 types of TRU waste planned to come to WIPP; contact handled waste, forming 97% by volume, and remote-handled waste. Contact-handled waste has an upper activity cut-off of 200 mrem/hour, remote-handled waste can be up to 1000 rem/hour. Repository rooms are 300 feet long, 13 feet high and 33 feet wide. The capacity is planned as approx 170,000 cuM of contact handled waste (comprising 880,000 drums) and 5000 canisters of remote-handled waste. The site is subject to RCRA regulations because of the hazardous waste content of most of the material. A test phase, involving 0.5% of the total inventory, (see below), was not originally expected to start until at least July 1990. It was originally intended to be a demonstration of the repository system, allowing data to be obtained which could be used to assist the final site licensing process. It is now planned to perform a limited number of tests on specially created waste containers, which bear little or no similarity to those planned for actual repository operations. The test phase The purported purpose of the test phase is to simulate conditions in the repository over a range of different time scales. It is to take place in a specially constructed room in the more recently excavated portion of the repository. This is known as Room 1, and was excavated in 1988. Because of a stipulation that the waste used in the test phase must be retrievable, the roof has been extensively strengthened, using a combination of 2 ft and 13 ft long roof bolts. A yieldable steel crib has also been installed which can be progressively lowered in order to control convergence. Therefore there is no comparison between the test room and the actual reality of repository operations. Indeed, many scientists, including apparently some of those actually involved on the programme itself, together with a National Academy of Sciences Panel, have accepted that the test phase as now planned could just as well be carried out on the surface. The tests will be conducted using specially designed steel test bins, which can each contain 5x 55 gallon drums. Each bin is instrumented, and will be filled with a variety of salt/backfill mixtures to 'simulate' conditions far into the future. The area of the repository originally constructed for the test phase is designated the Site and Preliminary Design Validation area (SPDV). In SPDV Room 1, excavated in 1983, there was a major roof fall in January 1991. The room has had to be abandoned. DOE originally estimated that it would take 25 years for the room to close. DOE are now claiming that data from the SPDV rooms allow them to accurately predict closure rates. These predictions have led them to change the original design of the test phase, move the tests to newly constructed rooms, and abandon the original test area. In November 1990 the EPA gave the go-ahead for the test-phase. This permission was contained in a variance of the normal rules, and insisted that the waste is stored in a 'readily retrievable' form. No handling of wastes is permitted other than for test purposes. There is no such intention for the repository as a whole. When a room is full it will be sealed with a mixture of crushed salt and bentonite. When the whole thing is full, they will seal all roadways etc. back to the shafts and then seal those as well. Originally, the total amount of waste to be used in the test phase was set at 8,500 drums over 5 years, but, given the nature of the tests and the problems with transport (see below), it is possible that as few as 25 drums may be used for the whole experiment. In September 1991, DOE Secretary James Watkins attempted to overcome the objections to the start-up of the test phase by announcing that shipments would begin in early October of that year. He enacted proceedings to withdraw the land from the Department of the Interior and transfer it to the DOE, which previous legislation had stipulated as necessary prior to operations at the site. The transfer was completed on October 1st 1991. Following the transfer, New Mexico officials announced that they intended to apply for a temporary restraining order in the US District Court, to prevent shipment of waste to the site from the Idaho National Engineering Laboratory (INEL). They claimed that the administrative land transfer was illegal under the Federal Land Policy and Management Act and that DOE had not obtained a hazardous waste permit from the State. The DOE postponed the first shipments of waste to WIPP for 6 weeks, to allow the District Court to consider the case put by New Mexico State officials. At the court hearing, officials claimed that the site has "passed none of the standards which apply to a nuclear waste repository...it is presently geologically unstable and cannot be predicted to remain intact." These arguments are in addition to the legal wrangle over land withdrawal. On 26th November 1991, Judge John Penn ruled that the Interior Secretary exceeded his authority when he transferred the WIPP site to the DOE and that the DOE had failed to prove that wastes stored there during the five-year test phase could be removed safely, if necessary. Judge Penn issued his ruling in the case concerning safety and land withdrawal in February 1992. He directed the DOE "to permanently cease all activities" until a hazardous waste permit is obtained from the state, anticipated to take up to 18 months. He also ruled that the land transfer must be put on hold until it has been approved by Congress. In June 1992, the President of the National Academy of Sciences wrote to the chairmen of the 3 Senate Committees involved in passage of a bill which would allow transfer of WIPP to the DOE, apparently to try and influence the vote. This followed release of an NAS panel report which was critical of the DOE's plans for the test phase at WIPP. The report recommended amending the tests to include geological and hydrological conditions, and suggested that the tests on waste material be conducted elsewhere. Opponents to WIPP will try to add a number of amendments to the Land Withdrawal Bill, which call i.a. for the EPA to issue standards for WIPP to comply with, prior to it opening; to certify the safety of DOE's testing and to approve a plan to retrieve wastes if the tests fail. The US Bureau of Mines could also be called upon to certify the condition of the mined repository. The Bill now exists in 2 versions, one from the Senate, the other from the House. The House Bill was passed at the end of July, and there is likely to be hard bargaining before it is passed, if ever, in the Senate. The EPA would have to oversee the environmental impact of the projected test-period, and the State of New Mexico would be given major powers over the whole WIPP project itself. Waste transport issues Wastes will be transported to WIPP in specially designed TRUPACT-II containers. There are currently 15 of these, at a cost of $250,000 each. It is intended to have 51 in all. Although licensed by the NRC, the TRUPACT-II container has yet to satisfy Quality Assurance requirements, needed to allow regular use of the system. They will be transported by truck, which will be satellite-monitored along the route. It is planned that during normal operations there will be 15 shipments a week arriving at WIPP, approx. 3 per day. Each truck will carry 3 TRUPACT-II containers, in turn containing 2 waste boxes capable of carrying fourteen 55-gallon drums. The waste handling system, as currently designed, is supposed to allow operators to work in street clothes. Although project literature describes how a special handling line will be used for remote-handled waste, this was not shown to us during the visit, although a hot cell, supposedly for use in a contamination incident ("constructed of cheap materials so as to be less costly to discard") was. The project literature describes this hot cell as an integral part of the remote- handled waste management system. Sources in Washington, close to the NWTRB, have pointed out that this hot cell would enable the waste handling facility to accept spent fuel. The complete handling system, as originally designed, did not envisage use of specially designed containers. As a result of the NRC demand that such containers be used, only 2 of the planned 3 handling lines were installed. It is planned to carry out a complete 'dry-run' exercise this Autumn, involving the loading, transporting and receipt of a single shipment of 3 TRUPACT-II containers from INEL to WIPP. This will allow the system to be reviewed for potential problem areas. Potential problems at WIPP 1. Pressurised brine; WIPP is constructed at a depth of 2150 feet in the Salado Formation, which is itself 2000 feet thick. Below it lies the Castile Formation, which has been discovered to contain brine pockets under pressure. Flows of several hundred gallons a minute have been encountered in bore holes drilled from the surface. The initial WIPP site was actually abandoned in 1975, when the first exploratory bore hole hit brine. The original site was selected by the AEC (now DOE) with very little preparatory investigation, based mainly on oil and gas exploration wells in the area. When Sandia took over the scientific control, the site was immediately moved, as intensely disturbed salt deposits were found to be present. In 1981 the planned orientation of the repository was altered when 700 million gallons of brine was located within the Castile Formation only some 500 feet below the planned repository horizon. The brine was encountered in a deep bore hole drilled as part of the site characterisation. The first shaft was also sunk in 1981 by a Japanese contractor, supervised at that time by the Army Corps of Engineers. This was followed by 3 further shafts. A study carried out in 1987 by the DOE has suggested that another reservoir of brine may be present 800 feet below the present position. However, this is not regarded by DOE as a potential hazard. 2. Water ingress; Water was first found to be entering the WIPP excavations in 1983. An NAS panel warned, in 1986, that rooms in the repository could become fully saturated within only a few hundred years. This information only became widely known following a report by the Scientists Review Panel in 1987. A special circular tunnel, known as the 'Q Room', has been excavated for use in assessing water inflows through the salt. It is the same length as a disposal room, but with a diameter of loft. There is a double airlock entry system to prevent moisture being artificially introduced. To date, according to Sandia, 4-5 gallons of brine have been collected in just over 2 years. No work has been done yet to determine whether this is a continuously replenished flow or is dewatering of the salt around the tunnel opening. There are no plans to investigate this. 3. Collapse of rooms and abnormal creep; DOE estimated, in 1983, when the first rooms were excavated, that it would take 25 years for closure to occur. This has been proved to be grossly inaccurate. As described above, it was originally planned to conduct the test phase in the rooms constructed at the beginning of the project in the Site Preliminary Design Validation area. However, monitoring of closure rates showed that some were not behaving as predicted. One room known as SPDV Room 1, suffered a major roof fall in January/February 1991, involving approx 1400 tonnes of material, despite a late attempt at roof bolting. This was revealed originally to a House of Representatives interior sub-committee in June 1991 by a group of scientists from the General Accounting Office. They concluded that the rooms for the test phase were crumbling so fast that their integrity could not be guaranteed, and that wastes emplaced there would not be retrievable as required by the test licence. DOE and Westinghouse convened a Panel of Experts in April 1991, which reported in June 1991. This Panel concluded that measures would need to be taken to strengthen the roof in rooms to be used in the test phase, if the retrieval requirement was to be met. SPDV Room 1 is not completely sealed at present, allowing viewing from the outside. There are huge blocks of salt and a considerable amount of debris visible, with a void developing above which is likely to continue propagating until it reaches the top of the weakened zone, likely to be at a competent anhydride layer some tens of feet into the roof sequence. The movement can be seen to be continuing, and wooden cribs installed at the entrances to some of the SPDV rooms can be seen to be beginning to deform, with loading pressures of several hundred pounds per square inch registering on instruments installed in them. 4. Natural resource issues; Known oil and gas reserves exist in the area around WIPP, and there is even an existing lease below the actual site. DOE is currently acquiring most of the leases in the area, in order to preclude exploration. However, when travelling to the repository from Carlsbad, it is possible to see 4 drilling rigs in operation less that 15 miles away. According to IAEA guidelines, a repository should not be sited in an area where it is likely that future generations could exploit natural resources. 5. Waste constituents; In addition to containing TRU wastes, the material to be disposed of at WIPP contains hazardous chemicals. WIPP is therefore also subject to the constraints of the Resource Conservation and Recovery Act (RCRA), which stipulates that wastes must be fully characterised before final disposal, and must satisfy a so-called "no-migration" clause. The DOE has acknowledged that information on the exact nature of up to 60% of the wastes is either inadequate or non-existent. Most of the waste is planned to come from the INEL complex in Idaho and Rocky Flats in Colorado. DOE has appealed against the application of RCRA to WIPP, and public meetings are planned for later this year. DOE has already been granted a 10-year exemption to the RCRA to allow the test phase to be carried out. 6. Gas generation; The chemical constituents of the wastes are such as to continually generate gases, which have the potential to cause over-pressuring of the repository and abnormal closure and ground water movement. One of the main objects of the original test-phase was to assess this problem. Unfortunately, due to the nature of the test phase as now planned, it is unclear as to how much useful data on gas generation will be available for long term predictions. The exact plans for gas generation experiments in the test phase are currently unavailable. 7. Capacity of WIPP in relation to total TRU inventory; There has also been concern expressed about the capacity of WIPP to solve the problem of TRU disposal. In 1990, some 62,000 m3 was in store in drummed form, with a total of 112,000 likely to be available for disposal by 2010 approx. This is what WIPP is designed to take, along with approx 5000 canisters of remote handled waste. However, taking into account the 190,000 m3 of TRU buried at various sites and up to 540,000 m3 of contaminated soil buried elsewhere, it is obvious that WIPP can clearly not cope with all the wastes that actually need disposal. The irony is that the wastes currently causing least danger, drummed and stored as they are at present, are the exact wastes planned for WIPP. Other problems also exist, such as missing documentation regarding safety analyses carried out at WIPP; poor quality control in construction of the surface and underground facilities etc. Conclusions 1. WIPP is in existence and ready (according to DOE) for the test phase to begin. 2. The exact program to be followed in the test phase has not yet been published, and as presently outlined is unlikely to be able to simulate true long-term repository conditions. Scientists on the project and from the NAS agree that the test phase may as well be conducted on the surface. No migration tests or experiments on the actual rock mass are included in the test phase, although results from it will be used to legitimate the whole repository system. 3. Because of roof control problems and the NRC demand for post test phase retrievability, the rooms to be used are being roof bolted and strengthened. As a result, conditions are totally divorced from those to be expected during real repository operations. 4. WIPP offers no solution to the management of the vast percentage of TRU wastes currently in existence. PJ Richardson, Consulting Geologist. September 1992 --------------------------------------------------- Yucca Mountain. This report summarises the current situation as regards this proposed repository for HLW, concentrating on the scientific aspects as opposed to the political. It incorporates information obtained during a visit by Antony Froggatt (GPI) and Phil Richardson (Geological Consultant, GPI), on 21st August 1992. It also includes observations and comments made to PJR during off- the-record discussion with the Executive Director of the NWTRB, in Washington, on 27th August 1992. Introduction Yucca Mountain in Nevada has been designated as the sole candidate site for HLW and SNF. Nearly $1 billion have already been spent on site investigation studies, but the repository is still no nearer approval, due in no small way to the extensive legal delays and obstacles which the State of Nevada has sought to put in the way of the DOE investigation. When originally designated as the sole repository site in 1987, the opening date was planned as 1998. By 1988 this had slipped to approx. 2003, and by late 1989, DOE was forced to announce that due to poor quality control and programme progress, the date was now 2010. The planned capacity of the repository is 70,000 tons, consisting of 60,000 tonnes of spent fuel and 10,000 tonnes of vitrified high level waste. Currently there are some 20,000 tons of spent fuel in store around the US, which is likely to rise to around 40,000 tons by 2000. This capacity is only designed to take account of spent fuel from the plant currently in operation. There can be no new reactors or plant life extension in this scenario. Current designs envisage over 100 miles of tunnels excavated approx. 1100 feet below the surface, covering an area of nearly 2 square miles. Preparations for an initial investigation phase (the Experimental Study Facility (ESF) are planned to begin in fiscal year 1993 (see below). The site is located approx 100 miles northwest of Las Vegas, on the edge of the Nevada Nuclear Test Site. The current estimate of total cost for the repository, including closure, is $6.3 billion. Current activities on-site To date, some 200 bore holes have been drilled. However, due to poor data management and quality control, the data from much of this (including as much as 40,000 feet of core) have been designated by the NRC as unusable for site licensing work. Core materials and samples are now subject to a detailed archiving process. Following legal wrangles over water-use permitting etc, drilling operations were allowed to restart in October 1991. To date, 12 shallow bore holes have been completed, for use in rock-matrix infiltration and flow studies using neutron monitoring equipment. Although considerable amounts of information are available as regards matrix flow through both welded and non-welded tufts across the site area, it is obvious that little or no work is currently being done on the flow characteristics of faults and fractures within the unsaturated zone (see below under hydrogeology). A deep bore hole is currently underway at site UZ-16, to the SE of the mountain crest. Currently down just over 500 feet, this is planned to go to approx. 1700 feet, and will be used to install geophysical equipment (for Vertical Seismic Profiling), although the exact purpose was not given; (VSP's are only able to provide local data in the vicinity of the bore hole). The ESF The Experimental Study Facility, as presently envisaged, is intended to consist of 2 access tunnels, driven sub-horizontally from south east of Boundary Ridge, into the body of the repository host formation in the Topopah Spring Member. It is planned to drive up to 14 miles of tunnel initially, although a complete repository would involve some 100 miles. The access ramps are planned to be 25 feet in diameter, making them potentially suitable for use in repository operations proper. Ancillary roadways may only be 15 feet diameter. It is planned to use a Robbins Tunnel Boring Machine (TBM) to construct the ramps. The Nuclear Waste Technical Review Board suggested in its last biennial report to DOE that underground studies should begin as soon as possible. It is planned to begin making the tunnel portal entrances by Spring 1993, with actual tunnel drivages intended for fiscal year 1994. Exact siting studies for final positioning of the portals is underway, involving trenching studies to try and locate faults and fractures which should be avoided. Sources close to the NWTRB in Washington have privately expressed concern that DOE intend to purchase 4 large-diameter boring machines prior to beginning the ESF drivage. This appears to preempt any possibility of discovering disqualifying factors during what is in truth only a reconnaissance stage of the project. Design teams for the ESF are based in Denver. Tests within the ESF are expected to take at least 7 or 8 years to complete. Only then will it be possible to submit full results to the NRC for use in licensing procedures. Again, sources close to the NWTRB have expressed concern at the use of 25-foot diameter tunnels for an experimental facility. Potential problems 1. Hydrogeology; Because of the depth of the water table in this area (approx 760 metres below the surface), the repository would be constructed within the so-called "unsaturated zone", where little or no water is encountered, and any movement would be expected to be downward from the surface. Below the water table, movement is expected to be generally downward and laterally away from the repository. a)Infiltration studies: Most workers consider that the biggest danger to repository integrity, as regards ground water movement, is not so much movement of water from depth, as suggested by Szymanski (see below), but rather the potential for rainwater to percolate down from the surface and pick up radionuclides as it passes through the repository. If this were then to move laterally and reach the surface, there is a potential for surface contamination. It is readily accepted that Yucca Mountain is fractured, not only by faults, of which 23 are in close proximity, but also by joints, which vary in their lateral and vertical extent and connectedness. Unfortunately, no bore holes to date have penetrated any of the known faults, such as the Ghost Dance Fault, which is likely to cross the repository at depth. Studies of surface expression of faults have been conducted, but it is of major concern to discover from USGS hydrologists at the site, that little or no work has been carried out on the flow potential of faults and fractures in the unsaturated zone. Studies elsewhere in the world have shown that due to effects such as channelling, the use of bulk conductivity values (as at Yucca) as a basis for predicting repository performance in fractured rock is next to meaningless. Sources close to the NWTRB in Washington indicated that this failure to conduct meaningful studies of fracture flow potential in the unsaturated zone is the single most worrying aspect of the whole site investigation to date. Bearing that in mind, and the fact that is usually considered that any site characterisation is only ever likely to be able to locate and map perhaps 60-70% of the total number of fractures present, then there is cause for concern at the studies being carried out by the DOE. The suggestion, mentioned below, that studies of the Ghost Dance Fault had actually shown that the affected zone was up to 100 metres wide was not confirmed by DOE. If true, and found to be typical of faults at depth, the capacity for anomalous water flow is considerable. Considerable debate exists as to the likely future hydrology of the area. Some, such as Szymanski, postulate that the water table has risen in the past, claiming evidence from calcite deposits, and may do so again, thereby negating many of the site's perceived benefits. DOE set up a specialist panel to examine these claims which recently reported that the evidence did not seem to support the theory. We were able to visit Trench 14, which has been excavated to expose the surface trace of the Bow Ridge Fault, in an attempt to provide information regarding the age and origin of the calcite deposits. Whilst samples have been taken which purport to show results which disprove Szymanski's hypothesis, we were told that it was not actually intended to deepen the trench to a depth sufficient to show that the calcite deposits failed at depth, thereby failing to actually remove the uncertainty totally. The SE Ramp is planned to start to the SW of the Bow Ridge Fault, and pass through it at a depth of around 200m. This should provide important data regarding the calcite deposits. DOE predict that it is plausible that the water table could be raised by as much as 500 feet by normal climatic change, if the area became appreciably wetter than at present. Indeed, approx. 70% of the last 10,000 years exhibit a wetter climate than present. 2. Volcanic activity; The rock at Yucca is volcanic. Known as tuft, it is the product of relatively recent (11 million years) explosive volcanic activity cent red some 20 miles away. This activity is reflected at the present day in the numerous ash and cinder cones of the area. As such it is vertically and laterally very variable, and extensive drilling is necessary for full characterisation. Debate exists as to the age of the last volcanic eruptions in the area, some estimates date the Lathrop Wells cone as active as recently as 5-10,000 years BP, despite earlier DOE estimates at over 100,000 years BP. DOE workers at Yucca Mountain suggested that very recent results indicated 20-50,000 years BP. The head of the Volcanic Studies Group, Bruce Crowe, gave an outline of the current state of knowledge as regards volcanicity. He acknowledged that it is still not clear as to the exact age of the Lathrop Wells centre, although he dismissed the very low age estimates mentioned by some workers. His greatest area of concern was as to whether the ESF would encounter volcanic intrusions beneath Yucca Mountain, which would mean that his theories on the volcanic system in the area were erroneous. Therefore he believed that the development of the ESF was the most important single activity in the future. 3. Seismic activity; There are also potential problems at the site from fault activity. Some 32 known active faults cross the overall site area, with one, the Ghost Dance Fault, actually passing through the repository as currently planned. Although this is estimated to have been inactive for 10 million years, uncertainty exists regarding the Paint Brush Canyon Fault, which passes within a mile of the site. According to sources close to the NWTRB in Washington, very recent geophysical work has indicated that a fractured zone up to 100 metres wide is associated with the Ghost Dance Fault. If this proves to be correct, there could be major repercussions for the repository layout, and also potential for similar disturbances adjacent to faults which are bound to be encountered during development. A 5.6 Magnitude earthquake, which struck Nevada in June this year, was cent red only 12 miles from the site, 9 Km below Little Skull Mountain, associated with the Rock Valley Fault, according to revised estimates. There was structural damage to some of the project buildings some 10 miles from Yucca Mountain proper. The main damage was to the Field Operations Centre, and amounted to some $1 million. We were able to examine this damage, which consisted mainly of blown-out windows and cracked masonry structures. The integrity of the stairwells has been breached, as regards fire regulations, and as such must be repaired. The quake took place on a fault which was not considered to be particularly active. 2 earthquakes also occurred in June in Southern California. These have been associated with a new shear zone, similar to the San Andreas Fault, by several geologists and geophysicists. The influence on the seismicity of the Yucca area is presently uncertain. Trenches are currently being excavated in the area of the proposed waste handling area associated with the access portals for the ESF, to try and locate the surface position of faults and to try and assess their recent movement history. The recent earthquake only highlights the potential for currently unknown faults to influence the seismicity of the area. DOE say that the peak ground acceleration of the recent quake, 0.1g, was within their design capacity of 0.6g. A longer database from strong ground motion recorders will show whether 0.1g was a typical value or not. There is also a potential for so-called "seismic pumping" to occur, where fault activity and associated earthquakes could drive ground water through the area in a very unpredictable way. Miscellaneous areas of concern Several other areas of uncertainty exist regarding the potential performance of Yucca Mountain, but which are not regarded by DOE as worthy of major study at this time. a) Deep sorption: Any ground water which might gain access to the repository by surface-sourced infiltration, will, according to the DOE, not generate a potentially hazardous source-term, due to the presence at depth of a strongly sorbing horizon of zeolite mineralisation at the contact between the Topopah Spring Formation and the Calico Hills Formation. Unfortunately, other workers regard this as only a partial barrier at best, which is incapable of slowing down the movement of some radionuclides, in particular iodine and carbon-14. DOE have done very little investigative work on this horizon, especially with regard to its potential to sorb colloidal species, which are likely to be important components of any source-term due to the probable presence of colloid-forming bacteria, which will be introduced into the repository environment during the operational phase. Elsewhere in the area, this zeolite horizon is actually the site of extensive hydrothermal mineralisation and alteration, indicating the potential for extensive fluid transport and migration. b) gaseous venting: Many people to whom we spoke referred to a phenomenon likened to the mountain "breathing". It appears that many of the fractures which are visible along the crest and steep eastern face of Yucca Mountain actually vent air rider certain weather conditions, and suck air in at other times. Independent studies show hundreds of such venting joints over just a small area on the surface. Interesting as this is, it has consequences for repository performance. It is generally accepted that the wastes in the repository will generate moderate quantities of gas, due to the chemical content and microbial activity. It is also probable that any water which gains access to the repository will also generate gases, such as carbon-14 and hydrogen, due to corrosion of steel. Dehydration of clay minerals and zeolites in the backfill is also a possibility, due to the thermal loading introduced by the wastes. If and when the vitrified HLW is also exposed to water - likely as the expected canister lifetime is unlikely to be more than 300 years at most- further gaseous actinide compounds and carbon-14 will be released. These will exhaust to the surface via interconnected fractures. c) Repository schedule: As outlined earlier, the original target opening date for a repository has slipped by 12 years, since Yucca Mountain was originally designated as sole candidate site in 1987. The Secretary of Energy announced in February 1990 that the work at Yucca mountain conducted thus far, at a cost approaching $1 billion, was not satisfactory, and that the timetable for the investigations was to be extended. The licence application is not now likely to be submitted before 2001, with repository operations not likely before 2010. The State of Nevada has said that it would block all applications by the DOE to restart testing, although in March 1992 the State granted the final water-use permit to DOE, allowing drilling to recommence. In May 1992, the Yucca Mountain program me director, John Bartlett, suggested that DOE may seek to begin operations earlier than currently anticipated, by only seeking initial licensing for a reduced scale demonstration phase, in the first instance. This would reduce the amount of site characterisation initially required, he said. There are concerns being expressed at the revised cost estimates for the project, which put the total cost of the repository at some $6.3 billion. Sources close to the NWTRB in Washington have indicated that unless DOE receives the full $375 million requested for fiscal year 1994, site work, especially that associated with the ESF, will have to be curtailed and a revised schedule announced. It was not considered unreasonable that such an announcement might be made in the near future. Conclusions 1. Over $1 billion have been spent at Yucca Mountain, yet DOE are still unable to decide whether the site is suitable for development. Much of the data obtained up to the present time is considered unsuitable for use in the licensing procedure. 2. Debate still continues regarding many of the basic geological questions at Yucca Mountain, such as hydrogeology, volcanism and seismicity. Despite this, DOE is still pushing ahead with plans to begin driving tunnels. 3. The hydrogeological research currently being carried out is not designed to address the major area of concern, namely the potential for rapid percolation of ground water, in the unsaturated zone, via faults and fractures. 4. Concern has been expressed that the planned ESF will be developed on a scale not in keeping with its supposed experimental nature. 5. Unless sufficient funding is granted, seen as unlikely by well-placed sources, it is probable that an announcement will be made, further delaying the project, in the near future. PJ Richardson. Consulting Geologist. September 1992