If the United States exhausts its high-grade uranium resources, then it will have to turn to lower grade resources. ERDA's current information is that the United States has no significant uranium resources in ores between 0.07 and 0.008 percent uranium by weight. The next major resource is in Chattanooga shale which is estimated by ERDA to contain approximately 13 million tons of UO, at a concentration ranging from 0.0080 to 0.0025 percent. [27] At 0.0050 percent the uranium in a ton of ore would have about the same energy value as fuel for a U.S. water-cooled reactor as a ton of coal for a coal-fueled powerplant. ERDA believes that most of the mining would have to be done underground. Current underground coal mining would fuel only approximately 125,000 megawatts of coal powerplant capacity at a 65-percent capacity factor. Approximately 100,000 equivalent full-time miners work to provide this coal. [28] Supporting a nuclear energy capacity of several hundred thousand megawatts by mining Chattanooga shale does not therefore appear to be an attractive prospect. The subcommittee also heard from Mr. Milton Searl who had a much more optimistic view than ERDA of the U.S. potential uranium resources. [29] Mr. Searl, manager of the energy supply studies program of the electric utilities' Electric Power Research Institute, expressed his belief that ERDA's current estimates of uranium resources in high-grade uranium ore will prove to be low for two principal reasons: 1. ERDA's resource estimates are dominated by ore deposits at relatively shallow depths. Mr. Searl suggested that this shallow distribution was not a result of the actual distribution of deposits with depth but instead simply reflected the fact that shallower deposits are easier to find. As support for this contention Mr. Searl noted that the average depth of ERDA's $8 per pound U.Os cost category of uranium reserves was approximately 400 feet in 1973-quite close to the average depth of exploratory drilling over the previous several years. [30] Searl pointed out that, if uranium ore were indeed distributed uniformly with depth down to say 4,000 feet, then the sum of ERDA's resource figure plus past production (assuming that it also was at an average depth of 400 feet) should be multiplied by approximately a factor of 5 to obtain a corrected estimate for resources. He noted, however, that the deeper uranium ore would be both more difficult to find and more costly to mine. 2. Not only is the exploration of the country at depth incomplete, it is also far from complete over the area of the United States. Mr. Searl testified that: "A review of the literature convinced us that the total prospective area in the United States potentially productive was 30 times the known producing area." Assuming that no areas with larger reserves remained to be discovered, he estimated on the basis of experience with the distribution of other mineral resources that other districts with a total uranium resource approximately three times greater than that of the currently producing area would be found. [30] Correcting the ERDA resource estimates for these two considerations would raise them by a factor of 20 to 72 million tons. In actual fact, in a document submitted for the record [30] Mr. Searl suggested, however, that the United States has a resources base of high-grade uranium ore in the range 13 to 29 million tons, for the entire United States. This estimate is not comparable to ERDA's current estimate, however, since it was based on a 1973 ERDA estimate of certain classes of reserves totaling 1 million tons. If Mr. Searl is correct, then there is much more high-grade uranium ore to be found in the United States beyond the 3 million tons of U¿Os equivalent estimated by ERDA. This would be in keeping with history where ERDA's estimates in one category for which we have historical information (less than $15 per pound Ú2O, forward costs*) have increased from 570,000 tons [31] in 1967 to approximately 1 million tons [31] in the period 1969-73, to approximately 2 million tons [26] at the beginning of 1975. Such arguments are not a sufficient basis for public policy, however, and it is important that the uncertainty in U.S. high-grade uranium resources be greatly reduced. Since 1958 uranium exploration has been left to industry with the AEC-now ERDA-largely playing the bookkeeper's role. This was adequate when the required forward reserve was 8 to 10 years current production and production was averaging only about 12,000 tons of UsOs per year. [25] With the projected demand rising to 40,000 tons per year before 1985, and the breeder decision depending upon the adequacy of our uranium reserves to supply the lifetime requirements of reactors built in the year 2000, however, it will be necessary to make an effort to identify uranium resources which goes beyond that which is justified by the short-term planning requirements of the uranium mining industry itself. In response to this obvious need, the AEC embarked in 1973 on its own national uranium resource evaluation (NURE) program funded at the level of $7 million [32] for fiscal years 1974 and 1975. The result in the first 18 months' work has been an increase of 1.2 million tons in ERDA's U2O, resource estimate. [24] This first phase of the NURE program which was programed to be completed by January 1976 involves the assembly and analysis of existing information with experienced uranium geologists making estimates based on industry data, field examinations, available geologic reports, discussion with other Federal, State, and university geologists, as well as their own experience and judgment. Each geographic area is examined and judged on key geologic characteristics and compared with areas of known uranium reserves and ore controls. [24] The second phase of the NURE program, which is to be completed by 1980, would involve ERDA developing new resource information through an aggressive program of geologic and geochemical investigations, geologic drilling and aerial and other geophysical surveys. [25] The NURE program would also include an effort to upgrade the exploration techniques of industry. The uranium industry expended approximately $50 million on exploration efforts in 1973 and has been rapidly increasing its efforts since. [25] It appears obvious that this program should be pursued with the highest priority. ERDA's uranium resource evaluation program should also be improved where possible. Mr. Searl suggested a number of possibilities for such improvements including: *Forward costs are ERDA's estimated costs for mining, hauling, and milling of the ore plus royalties. It does not include "sunk costs," such as costs already expended in exploration and property acquisition nor does it include profits or interest. Due to inflation and sometimes the closing of mines, the more expensive ore in a particular forward cost category will tend to move into the next higher category. In order for resources to increase therefore, the rate of discovery of new resources must exceed the rate of mining plus 1. An assessment of whether past exploration efforts ignored uranium deposits which were not then of economic interest but might be by the end of the century.* 2. A systematic approach to understanding the distribution of uranium deposits as a function of depth, size, and grade. 3. Making ERDA's data bank on uranium resources more accessible to outside analysts who might be able to suggest improvements in ERDA's approach to the problem. In view of the importance of the uranium resource question, it might be appropriate to convene a qualified review group-possibly under the auspices of the National Academy of Sciences-to review the NURE program. This review should assess the adequacy of the coverage of this program as well as the effectiveness with which it utilizes the expertise available in other Government agencies such as the U.S. Geological Survey and in universities. A considerably higher level of funding for the uranium resource assessment program could be justified if such funds could be effectively spent. IV. OTHER URANIUM CONSERVING REACTORS The discussion above has ignored the fact that there are more than the two types of nuclear reactors discussed so far: The standard U.S. light water cooled reactor (LWR) and the proposed liquid metal cooled fast breeder reactor (LMFBR). In fact, in addition to other proposed breeder reactor designs, there are at least two additional developed reactor types whose requirements for uranium per kilowatt hours of electricity generated would lie between those of the LWR and LMFBR. These reactors are the commercially successful Canadian heavy water reactor (CANDU) and the U.S. high-temperature gascooled reactor (HTGR) whose commercial future is currently in question. Use of these two reactor types would reduce the uranium requirements per kilowatt hour by a factor of approximately two with either a once through or a recycle fission economy. (See app. E.) In practice, of course, there would be difficulties in substituting these reactors for LWR's in the U.S. reactor market. Neither the HTGR nor the CANDU has an obvious economic advantage over the lightwater reactors with the uranium prices expected over the next decade or so and they have the disadvantage of competing with an established reactor type. In addition, even if the reluctance of the market could be overcome, it would take a considerable time before the industry could be geared up to produce either of these reactor types in quantities comparable to the numbers of light-water reactors currently being built. It should be noted, however, that both of these objections apply at least as strongly to the LMFBR. 1. THE THORIUM ECONOMY AND "NEAR BREEDERS" If a decision were made to go to a fuel recycle economy with any of the current generation of commercial power reactors, then the greatest conservation of uranium would be possible if the uranium 235 were separated from the uranium 238 which makes up the remaining 99.3 percent of natural uranium and were mixed with thorium instead. *One wonders in this connection whether it might not be possible to "piggyback" a great deal of uranium exploration on drilling efforts aimed at deevloping new oil and gas reserves. 233 In such an arrangement a new chain reacting element uranium would be bred out of the thorium instead of the plutonium which is bred out of uranium 238. For the LWR, HTGR, and CANDU which all use slowed down neutrons in their chain reactions, conversion in the thorium-uranium fuel cycle would be somewhat more efficient than in the uranium-plutonium fuel cycle. The opposite is true for the LMFBR which uses fast neutrons in the chain reaction. One advantage of the uranium-thorium fuel cycle is that use of it would allow an evolutionary development of current reactor designs toward designs which would use uranium more and more efficiently. Thus both the HTGR and the CANDU could probably be upgraded to at least near-breeder status. [33] In fact ERDA is currently funding what is intrinsically a more difficult development project: the upgrading of the Shippingport light water cooled reactor to the status of a breakeven breeder reactor-a reactor which utilizes uranium as efficiently as the proposed LMFBR but unlike the LMFBR does not breed significant amounts of surplus fissionable material to fuel new reactors. [33] With ERDA's projected growth rate for the U.S. nuclear power capacity and its estimates of U.S. uranium reserves, it would probably be impossible to introduce HTGR's or CANDU's rapidly enough to prevent a severe uranium shortage with the LMFBR. In fact in the short term uranium supply and enrichment capacity problem might be exacerbated by the introduction of uranium conserving reactors since many designs have greater initial fuel requirements than conventional reactors although their requirements for makeup fuel are less. In such designs it might be a decade after initial operation before the net savings began to accrue. [33] If the nuclear power growth rate turns out to be significantly slower or U.S. uranium resources are found to be significantly larger. however, then this option might prove to be quite attractive. An added incentive for exploring it is provided by the fact that the uranium-thorium fuel cycle might have advantages over the uranium-plutonium fuel cycle with respect to environmental contamination and/or safeguards against diversion of fuel materials to use in nuclear explosives. 2. OTHER BREEDER REACTORS In addition to the LMFBR two other breeder reactor concepts have been seriously put forward by U.S. nuclear energy technologists: the molten salt breeder reactor (MSBR) and the gas cooled fast breeder reactor (GFBR). Molten Salt Breeder Reactor (MSBR).-The molten salt breeder reactor is a concept which has been developed and embodied in a small test reactor at Oak Ridge National Laboratory. It is a reactor which operates on a thorium fuel cycle with thermal neutrons. It is promoted from a near breeder to breeder status by having its fuel in molten form mixed with the coolant. This makes it possible to purify and reevele the fuel continuously thereby keeping neutron capturing impurities at a lower level than would be feasible with a solid fueled reactor. Over the past several years the MSBR development program has been maintained at a level sufficient to conduct research and devel a potential backup to solid fuel breeder reactors. [34] In the administration's proposed fiscal 1977 budget no funds are included for the continuation of the development of the MSBR. Gas Cooled Fast Breeder Reactor-This is a concept developed principally by the General Atomics Co. with some utility and Federal support. The idea is to combine the helium coolant and prestressed concrete pressure vessel technology developed by General Atomics for the HTGR with the LMFBR fuel technology being developed by ERDA. The helium coolant of the GFBR would interfere less with the passage of neutrons from fuel rod to fuel rod in the reactor core than would the liquid sodium coolant in the LMFBR. As a result the GFBR would have a somewhat higher breeding ratio. The GFBR would have the safety disadvantage, however, that its coolant would be under high pressure and would consequently be expelled in case of a rupture in the pressure vessel. Currently the LMFBR concept is receiving the overwhelming percentage of breeder reactor development funding, both in the United States and elsewhere. Some experts have suggested that it may prove to be a false economy not to have developed more aggressively an alternative breeder concept if the LMFBR development program produces a reactor which is either not sufficiently safe or economic or if the plutonium economy proves to be unacceptable for either environmental or safeguards reasons. In such a case a thermal breeder reactor or near breeder based on the thorium economy would differ in enough respects from the LMFBR so that it might not encounter the same objections. V. ECONOMICS A breeder system reactor would only require about 2 percent as much uranium to be mined as a light-water reactor per kilowatt-hour of energy generated. The fact that this would stretch U.S. uranium resources has already been mentioned. It would also be an economic advantage, however, which would increase as high-grade uranium ores became depleted and the price of uranium increased. On the other hand, the capital costs for LMFBR's would probably be higher than those of a light-water reactor. (See app. F.) Dr. John J. Taylor, then vice president and general manager for Advanced Nuclear Energy Systems at the Westinghouse Electric Corp., the prime contractor for the Clinch River LMFBR demonstrator reactor told the subcommittee on June 6, 1975, that he believed that a commercial LMFBR in 1990 would have a plant capital cost than a water reactor of equivalent capacity $125 higher per kilowatt generating capacity-1982 dollars. [35] Similar conclusions had been arrived at by the Studies and Evaluation Group of Oak Ridge National Laboratory. [36] In order for the first LMFBR's to be a commercial success, it would be necessary for their capital cost disadvantage to be made up by savings in fuel costs. The subcommittee heard testimony from Dr. Thomas R. Stauffer, an economist at Harvard University, on this point. [37] Stauffer presented a preview of an analysis of the economics of the LMFBR done by himself, R. S. Palmer (General Electric), and H. L. Wycoff (Commonwealth Edison Co.) for the Breeder |