John W. Landis, President Gulf General Atomic Company Son Diego, California 92138
Fusion Power Hallmark of the 27st century
T o those of you just getting used to the idea that nuclear fission is replacing fossil fuels as an energy source for generating electric power, it may seem premature to he talking about an even more advanced energy sourcecontrolled thermonuclear fusion. But there is considerable justification for this seemingly visionary diversion. Firsta little background. About a year ago, President Nixon announced his intention to give the highest priority in the national energy program to development of the fast breeder reactor, which, as you know, is an advanced concept of the fission type that produces more fissionable material than i t consumes. The breeder, in combination with other varieties of fission reactors like the high-temperature gas-cooled reactor, will make i t feasible for us to "burn" the large quantities of low-grade thorium and uranium ores that are available in many areas of the world and, unless we are unable to solve its complex safety and design problems, will provide us with a low-cost energy source for many decades. Why then, one might ask, should we listen to pleas for immediate increases in financial sumort for fusion development in the United States? ~ndeed,there are those who are inclined. considerine the limited research dollars available for nuclear energy, to throw even more support to the hreeder Droeram a t the exoense of the fusion roe ram-their reasoniig 6eing that aLsuccessful breeder would allow plenty of time and elbow room for fusion development. I believe that there is a serious flaw in this sort of reasoning. We need the hreeder reactor and should vigorously pursue its development. I t will fill one of the most desperate needs of mankind in a critical period of history. But many would agree it is not the ultimate answer to the world's energy requirements. For one thing, it generates large amounts of highly radioactive material, material that must he stored in failproof containers for centuries. For another, its fuel-plutonium-is highly toxic and therefore must he carefully, continuously, and expensively safeguarded. For these and other reasons, the promise of a cleaner, safer, more economic, and practically inexhaustible energy source through controlled thermonuclear fusion cannot be ignored. It must he pursued relentlessly. The eventual benefits are so great that even on a crass present-worth basis, expenditure of great sums of money today in pursuit of this goal is warranted. The Energy Problem The future roles of hoth fission and fusion can more clearly he seen if we review for a moment the enormous trilateral problem of (1) vastly increasing energy demands. (2) ~oor-aualitv . . and diminishing" conventional fuel supplies, and (3) a deteriorating environment. The mowth of enerev use in the United States has been 'Talk given before the California Association ot Chern~stryTeachers. University of California. San Diem California. Mav 12.1973.
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phenomenal, far outpacing our rapid growth in population.' For example, in the decade from 1958 to 1968, annual consumption rose from about 40,000 trillion Btu to 62,000 trillion Btu-an increase of over 50%. Many experts expect this rate of growth to continue and predict that annual consumption will reach 170,000 trillion Btu by the year 2000. If this expectation is borne out, we shall expend the fantastic total of 3.4 x 101s Btu in the 32-yr period between 1968 and 2000. This would he equivalent to the energy contained in 590 billion barrels of crude oil or 170 billion tons of average grade coal (assuming 20 million Btu per ton), and would be almost three times as much as the energy expended in the 32 yr prior to 1968. The demand for electric energy is climbing quite a hit more rapidly than for other types of energy and will probably constitute 40% of the total by the end of the century. The Federal Power Commission estimates that the electric power industry will have to plan, finance, build, and put into operation some 1600 million kW of additional electric generating capacity by that time. This represents an increase of over fiue times our total 1970 capacity of about 300 million kW. In view of the vast amount of energy already consumed in the United States and the increasing amount called for in the near future, it should come as no surprise to anyone that we shall soon he straining our fossil-fuel resources to the utmost. Although danger of running completely out of these fuels is not imminent, we are already experiencing difficulty in meeting the demand for clean-burning natural gas and low-sulfur oil and coal. The proven reserves of natural gas in the nation, exclusive of Alaska, are about 259.6 trillion ft3, which is only a 12-yr supply. Even if the predicted new finds materialize, these reserves are expected to drop to a 10-yr supply by 1974 and even lower in the ensuing few years. Our proven domestic oil reserves are down to between a 7- and 8-yr supply and will continue to fall steadily. Coal is plentiful, hut economic and envimnmental considerations prevent the use of most of it-although new methods of sulfur removal both from powerplant stacks and from the coal itself during processing are being developed and could improve this situation. Tied in closely with our need for more enerw is our deep concern over the quality of our environment. The use of fossil fuels to generate electricity has added considerably to air contagination throughout much of the country. There are many days when we simply ask too much of our respiratory systems. This situation will he greatly alleviated by the use of nuclear energy. I shall not dwell on the problem of environmental pollution. More words have been generated about this problem in the last few years than in all preceding history, and I will spare you further repetition of things you already know. One important point that is sometimes overlooked, however, is that the only convenient form of energy for the multitudinous recycling and purification systems needed to solve this problem is electricity-and, as I have implied, the most sensible source of electricity is the nuclear pair-fission and fusion. I do not intend to slur or slight coal in this regardmerely recognize its limitations. It will he around a long
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time and utilities will use i t heavily in certain areas and under certain conditions. Much work remains to be done, however, to insure that it meets the rigorous air-contamination requirements of the National Environmental Policy Act of 1969. Fission as an Energy Source
In my view, present-day "light-water" reactors have come along just in time to save our nation from grave shortages of fossil fuels and from a disastrous increase in air pollution. These reactors will soon he supplemented by the high-temperature gas-cooled reactors that I have already mentioned. The latter, because of their higher efficiencies. better utilization of fuel. and lesser quantities of radioactive effluent, are more acceptable power-genetatinz systems from both the environmental and the economic standpoints, hut they will stretch our nuclear fuel reserves a t the most only by a factor of eight. Thus they are by no means the ultimate answer to the nation's (or the world's) energy-supply problem-just as the breeder reactors are not. The breeder reactors, however, are a step farther down the road. They will stretch our supplies of nuclear fuel by about a factor of 40 and consequently will come much closer to satisfying the huge demands of future societies for power, an appetite that as I have indicated will be tmly horrendous. The scientific feasibility of the breeder reactor has been proven. The first electric power from fission was, in fact, delivered by a reactor of this type, EBR-1, way back in 1951-although the power level was only about 100 kW. Since then, EBR-2 and a commercial prototype, the Enrico Fermi plant on the Detroit Edison Company system, have established beyond doubt that breeder reactors will work. Proof of economic feasibility is a different story, however. In view of the complex safety and design problems that I have referred to, this will take quite a number of years. The most educated guesses being made today are that these reactors will not be delivering competitive power until about 1990. In the breeder, to give you a capsule summary just for the record, fertile material (U-238 or Th-232) is transformed into new fissile material (Pu-239 or U-233) by excess neutrons from the fission reaction. Typically, the core of the reactor, containing both fissile and fertile material, is encompassed by more fertile material, either thorium or uranium, in what is euphemistically called a "blanket." One of the quantitative measures of the transformation from fertile to fissile material is known as "douhling time." This is defined as the time required for the reactor to convert enough fertile material to fissile material to both refuel itself and provide enough fuel to run another reactor of the same size. Doubling time for breeders of the "fast" or unmoderated type-the type that I shall confine my discussion to-ranges from seven to fifteen years. Decisions made by the AEC about twelve years ago led to the choice of liquid metal as the preferred coolant for fast breeder reactors; hence the name Liquid Metal Fast Breeder Reactor (LMFBR). The lion's share of the dollars assigned to the national breeder program by the AEC has therefore gone into this kind of system. An attractive alternative, however, is helium cooling, which is being developed quite independently of the AEC by Gulf General Atomic under what is known as the Gas-Cooled Fast Reactor (GCFR) Program. This program is being jointly supported by a large group of utilities and GGA's parent corporation, Gulf Oil. Helium cooling has both advantages and disadvantages when compared with sodium cooling. The principal advantages are 1) Helium has a negligible interaction with neutrons and therefore permits a higher breeding ratio (faster transmutation).
2) Because it is chemically inert and does not become significantly radioactive, helium facilitates maintenance and obviates the need for an intermediate cooling loop and an inert atmosphere in the reactor containment. 3) Helium cannot boil or form local voids and thus eliminates severaLdifficultcore-design problems found in the LMFBR. 4) Due to helium's high transparency, visual control during fueling and maintenance operations is possible. 5) There can be no total loss of coolant with helium because the reactor containment, filled with air, is always designed for an equilibrium condition of at least 2 atm.
The principal disadvantages are 1) Natural-convection cooling with helium is insignificant, thus creating the need for a combined main circulation system and backup circulation system which literally never fails. 2) More power is required to circulate helium than sodium for a given plant rating. 3) Failure of a pressure envelope containing helium at 70-1W atm can result in a rapid pressure drop with a corresponding increase in the difficulty of providing forced cooling. This requires an extremely reliable and redundant reactor vessel equipped with flaw limiters at each penetration.
The extensive know-how obtained from the high-temperature gas-cooled reactors a t Peach Bottom in Pennsylvania and Fort St. Vrain in Colorado has already been put to good use in solving these problems-which leads to an important point: Development of the GCFR will take only a fraction of the money being put into the LMFBR. This comes about because the GCFR is not based on new technology. The technology of the nuclear-steam-supply and containment systems is but an adaptation of that already proven for the high-temperature gas-cooled reactor. The fuel used will be essentially the same as that for the LMFBR. The cost of adding the GCFR to the national breeder program would therefore be relatively small. If this step were taken-that is, if the GCFR were added to the national breeder program-the public would reap a t least two major benefits: (1) competition between two different technologies instead of just between detaildesign and manufacturing skills, and (2) an alternate route to success in the vital breeder area. Fusion as an Energy Source
Let us turn now from the breeder reactor, which we are reasonably confident will someday take its turn at playing the leading role in the continuing drama of energy supply, to the potentially far better energy source that I am here to talk about-controlled thermonuclear fusion. This yet-to-be-developed concept, as I have said, offers us the promise of a safer, more economic, and, for all practical purposes, infinite source of electric energy, and may he the answer to many of our environmental problems as well. Perhaps we should take a few minutes before getting into the details of the fusion program to summarize the bases for these rather grandiose claims. The fusion fuel cycle will create very little radioactive waste because the chief radioactive product, tritium, will be recycled. The structural material of a fusion reactor will probably become quite "hot," and it may have to be discarded ~eriodicallv.but this should be a minor consideration compared to disposing of a fission reactor's waste. Thermal efficiencies of first-zeneration fusion plants will be comparable to those of the most modern fossil-fuel installations and high-temperature gas-cooled reactors (about 40%). Later plants will use direct-conversion devices and could have thermal efficiencies of up to 90%, thus practically eliminating the problems related to discharge of waste heat to the environment. At any given time, a fusion reactor will contain only enough fuel for about a second of operation. Consequently, a runaway is impossible. The stored magnetic energy will pose a rather serious hazard, but this should be of no Volume 50, Number 10, October 1973 / 659
greater magnitude than those created by the high pressures in present-day power plants. The inherent safetv advantaees of fusion reactors clearlv will also he economic advantages. The cost of transporting and storine radioactive wastes will be relatively low. Eneineered sacguards, control devices, and s a f e t i instrumentation will be relatively simple. Additionally, these reactors can he located virtually in the heart of population centers, thereby cutting transmission costs and making the reject heat available for sundry industrial and commercial applications, such as desalination and refrigeration. So much for the rationale of fusion development. Development of the Fusion Reactor
The physics problems involved in proving the scientific feasibility of a fusion reaction are well documented,2,3 so I will touch on them only briefly here. Most effort to date (representing a total of over a billion dollars worth of research work around the world, with about four hundred million having been spent here in the United States) bas been in the area of magnetic confinement. Recently laser technology has entered the picture; however; and the possibility of laser-heating an endless stream of small pellets of solid deuterium-tritium to thermonuclear conditions before they have time to disassemble is under intensive study. Nevertheless, laser-fusion methods are in quite an embryonic state, so I doubt that anyone in the field has formed more than an intuitive judgment regarding the practicality of the laser system, particularly as to the cost of supplying very accurately timed, large slugs of power to the continuous series of fuel pellets and the feasibility of transporting the heat-energy to a prime mover. With respect to the work on magnetic confinement, the immediate goal is to sustain a controlled fusion reaction for about 1 sec. For a fusion reaction to occur at all, even for a trillionth of a second, the positively charged nuclei involved must have velocities of approximately 100,000,000 cm/sec, corresponding to particle energies of 10 keV, to overcome their natural repulsion and get close enough together for the nuclear forces to take over. T o achieve these velocities by thermal means, temperatures of from 50,000,000 to 100,000,000"K are required. Relatively low densities of about 10'5 particles/cm3 are a necessarv condition a t these temoeratures. A major breakthrough in t h e attempt to prove the scientific feasibility of fusion occurred in 1969 when the Russian ~ o k a m a k - 3device, which uses a toroidal-shaped magnetic container, achieved a confinement time of 0.02 sec a t 5,000,000"K. This was ten times the previous maximum confinement time. This achievement by the Russians gave new heart to fusion researchers all around the world. Here in the United States, where programs are under way in four national laboratories, several universities, and a t Gulf General Atomic, primary emphasis now is on Tokamak-like devices, and fusion research leaders generally agree that, given adequate funding, scientific feasibility will he demonstrated by 1980. Once i t has been demonstrated, however, we will still he faced with the much thornier task of proving the economic advantage of converting fusion energy to useful power. Many of these problems have barely been defined, much less dealt with. I t is this important area that we now turn to.
vestigation provide a preview of some, hut by no means all, of the problems that must be licked. Two isotopes of hydrogen-deuterium and tritium-are involved in the fuel cycle currently receiving the most attention. The D-T cycle, as it is called, is favored chiefly because it requires lower temperatures than the other attractive cycles, such as deuterium/deuterium and deuterium/helium-3. The D-T reaction produces 8090 of its energy in the form of 14-MeV neutrons and the remainder in the form of charged helium-4 nuclei. Thus one main problem is conversion of the neutron energy to usable heat. I t is expected that the helium-4 particles will be trapped in the plasma, partially compensating for radiation losses. Conversion of the neutron enerev -.must be done bv. olac. ing suitable absorption materials and cooling systems around the olasma. These materials are usuallv referred to as the "reactor blanket." This structure invo1;es a host of engineering tradeoffs, as I shall try to point out. Since the plasma is a relatively good vacuum, the metal surface surroundine it is identified as the "vacuum wall." This structure, too,ls a complicated exercise in design. And of coune, the confinement of the plasma in an efficient way is one of the most demanding assignments ever laid before U. S. technologists. Let us take a look a t some of the basic requirements of the reactor hlanket, the vacuum wall, and the plasmaconfinement scheme.
Converting Fusion Energy to Useful Power
1) A provision for breeding tritium will have to be made because it does not occur naturally in appreciable quantities and producing it by other means would he too expensive. The reactions of Li-6 with slow neutrons and Li-7 with fast neutrons yield adequate amounts of tritium for fusion purposes. Therefore, the reactor blanket probably will incorporate a large amount of lithium. In effect, then, the primary fuels for the D-T fuel cycle will be deuterium and lithium. Neutron ealculations for typical blanket designs show that breeding ratios of 1.2 to 1.5 are reasonably attainable. These ratios are high enough for any foreseeable fusionpower economy. 2) Bath the vacuum wall and the reactor blanket will most probablv have to he located within the magnetic field. This field. generated by electric coils accounting for ;significant fraction of the total reactor cost, poses an extremely frustrating dilemma. Our thinking now is that superconducting coils operating at very low temperatures must he used. Because of the sensitivity of cryogenic systems to temperature, the heat load in these coils must he kept very small. In particular, they must not only be thermally insulated, they must also be shielded from radiation. The best way to provide this shielding is t o use the reactor blanket. This dictates a minimum thickness of 1-2 m for the blanket, which in turn increases the size of the eoils and the magnitude of their currents-and therefore their sensitivity to temperature and other transients. And so on around the vicious circle. 3) Neutron damage is a serious problem for hoth fission and fusion reactors, hut the fusion reactor undoubtedly bas the worse situation. Not only is most of its energy concentrated in its neutrans, those neutrons are about ten times as energetic as fission neutrons (14 MeV versus 1-2 MeV). These high-energy neutrons produce significant atomic displacements in structural materials and also significant quantities of helium and hydrogen thmugh n-p and n-a reactions. Hopefully, most of the displacements will anneal out, and the hydrogen will diffuse out, a t operating temperatures. Helium, however, may collect in voids, forming huhbles, and considerably alter the basic properties of the structural materials in both the vacuum wall and the reactor hlanket. There are no 14-MeV neutron sources available today with sufficient intensity to provide a test bed far fusion structural materials. It may be that we shall have to wait for the operation of higb-power fusion reactors themselves to learn what we need to know about neutron effects. The solution t o the neutron-damage problem is obviously either to develop resistant materials or to
The construction and operation of hoth experimental and demonstration fusion-reactor plants will be necessary. In these stages, realistic solutions to the vast array of engineering prohlems will have to be developed. The fuel cycles and plasma-confinement methods presently under in-
ZRose, D. J., "Controlled Nuclear Fusion: Status and Outlook," Science. 172. No. 3985,797 (1971). 3 Gough, W. C., and Eastlund, B. J., "The Prospects of Fusion Power,"Sei. Am., 224, No. 2,50 (1971).
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provide for frequent replacement of components. The relative merits of these two approaches are of course not clear, since we do not have the basic information required for an evaluation. 4) The question of cooling the blanket and using the heat far power production has many possible answers. Liquid lithium has heen proposed as the working fluid because lithium is required for tritium breeding. Use of lithium would create grave difficulties, however, including that of the large flow-resistance generated when a good conductor is pumped across a strong magnetic field. Use of lithium-beryllium fluoride would reduce this resistance because it has less electrical conductivity than pure lithium, but the presence of fluorine might overshadow any benefits that would accrue. Also, the tritium breeding ratio would be reduced and large amounts of gamma radiation would result from inelastic scattering of neutrons. This radiation would add greatly to the heat load in the superconducting coils and perhaps raise the operating temperature of the vacuum wall beyond the limits of known alloys. The use of pressurized helium as a coolant not only has some of the advantages that I have cited for fission reactors, but also, because helium is a nonconductor, has the additional advantage of not producing counter magnetic fields. The mechanical requirements of helium cooling include incorporation of tubing in the reactor blanket, which would somewhat increase the size of the reactor. This slight penalty would be compensated far many times over, however, by the ease with which helium crosses magnetic lines and the capability for coupling with direct-cycle gas turbines and dry cooling towers that it provides. There are many ideas as to how a fusion-powered electric generating station might be laid out. At Gulf General Atomic we have envisaged a system employing a reactor of the Doublet configuration and helium cooling, with the power heing produced in closed-cycle gas turbines and the waste heat heing rejected to a water-purification plant. The Doublet concept, which I shall explain in a moment, was invented by a GGA scientist, Tihiro Ohkawa. An artist's rendition of a full-scale version of a reactor of this type is shown in Figure 1. The approximate size of this device is 30 X 30 ft for a unit in the nominal range of 1000 MW(e). (The balance of size versus power has not been carefully worked out and the numbers aiven are only Note the two . ap~roximate.) .. dark coils surrounding the plasma region. A current in the inner (primary) coil with periods on the order of seconds induces a current in t h e plasma, which provides heat through ohmic resistance. It is hoped that this heat will brine the olasma UD to ienition temperature (approximatlly IOO,.OOO,OOO~K for tG D-T reaction). ~f it ddei not, auxiliarv heatina will have to be employed. The outer (superconducting confinement) coil keeps the plasma in its prescribed "orbit." Of special significance is the hour-glass or embryo shape of the plasma region. This is a unique characteristic of the Doublet confinement scheme. This shape gives rise to a
quadrapole-like magnetic-field configuration and yields a considerable advantage in plasma stability and confinement efficiency. By contrast the Tokamak has a circular plasma cross-section and a much lower confinement efficiency. The superior characteristics of the Doublet configuration are evident from the following: The hot plasma has a pressure in the range of 50 to 100 psi, which must he contained by the magnetic field. To have stable conditions in either the Doublet or Tokamak configuration, the confining or restraining magnetic-field pressure must he considerably larger than the plasma pressure. In the Tokamak, the overpressure factor must be about 100; in the Doublet i t must be only from 10 to 20. Thus, for confinement of a 50-psi plasma, Tokamak requires a magnetic-field pressure of 5000 psi while, optimistically, Doublet requires something like 500 psi. These magnetic-field pressures are crucial. They must be supported by the structure for the magnetic-field windings just as gas pressure must be supported by a pressure vessel. Thus, heavv structures operating a t cwoaenic temperatures wiil he required, which aggravates t h e dilemma I have already mentioned. This and other considerations may actually preclude the scaling up of Tokamak to power-reactor size, whereas Doublet, with its smaller magnetic field, probably can he scaled up. Figure 2 illustrates the power end of a fusion plant employing a direct-cycle gas turbine. Included are the reactor, turbine, circulators, cooler for heat rejection, and regenerative heat exchanger to increase plant efficiency. The helium-cooled concept has been studied to determine what performance can he expected when the helium is coupled either to a direct-cycle gas turbine or to a secondary steam turbine. It has not yet been decided which of these two alternatives will be used. If temperatures do not exceed 800°C, the steam cycle provides the better efficiency -up to 40%. If the system is designed to produce hot gases in the range of 900-100O0C, however, the direct-cycle gas turbine yields the better efficiency-up to 55%. Use of a gas turbine also has the environmental advantage of allowing reject heat to be discharged directly to the atmosnhere throueh drv - cooline" towers. which would essentially eliminate the need for cooling water. The simplicity and resultant economies of a direct-cycle plant are significant. Hopefully, the components developed in the fission-power program for such a plant will be directly applicable to the f&in-power program.
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Future Fusion Power Programs
As can readily be seen from the complex problems involved and the mammoth scientific and engineering effort
POWER CYCLE
Figure 1. Doublet concept of fusion reactor
Figure 2. The power cycle of a fusion plant u s n g a drect-cycle gas turbine.
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necessary to solve them, nuclear fusion for the production of electric power is not just around the comer. The histories of other capital equipment indicate that i t takes a development effort of a t least 30 yr to hring a new concept from the scientific feasihility stage to a point where it is a major factor in the economy. Although fusion reactors are not starting from scratch (much of the technology already developed for fission reactors will he applicable to them), I doubt that they will break this 30-yr harrier. In summary, I believe that a number of energy sources for electric power generation will coexist for many years. As in the past, however, (wood was the dominant fuel supply in the 1860s, giving way to coal by 1900, which in turn bowed to oil and natural gas in the 1950's, which in turn are yielding to light-water reactors right now) the dominance of one source over another will gradually shift. Economic and environmental considerations will he the prime factors determining the rapidity and direction of these shifts. In the near future, advanced converter reactors, such as the high-temperature gas-cooled reactor, will compete with existing sources. Then the first-generation hreeder n ewith-and reactors will take their d a c e in line. c o m.~ e t i.. perhaps symbiotically khpporting-the advanced converters. Fusion reactors should join the spectrum shortly after the turn of the century. The proposed schedule a t Gulf General Atomic for research and development leading to a fusion reactor is typical 1) Doublet 11, which went into operation in late 1971, is now producing the experimental data needed for the design of a fol-
low-on device large enough to prove scientific feasibility. It will he kept in service through 1976. 2) Doublet JII will be put into operation hy 1977; scientific feasibility tests will be run through 1979. 3) A reactor experiment will he built in the 1980s far start-up in 1988. 4) A demonstration plant will be built in the 1990s for start-up in 2000.
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5) A commercial plant will he constructed during the fint decade ofthe next century for operation by 2010.
The major point I would like to make is that the principal energy sources of the future, both fission and fusion, are equally important and that each will have its "day" in history. Fusion research should he given a high priority now if the schedule I have just outlined is to he met and we are to avail ourselves of its great benefits a t the earliest possible date. This does not mean necessarily that funding should he sharply increased. I t means primarily that we should look ahead, plan a sensible program, and follow it! This proposal may sound optimistic in view of recent federal budget cutbacks, hut I think i t is time we put some of our national goals in proper perspective. Reputable engineers have estimated that we can develop commercial fusion reactors a t a cost of $4-5 billion dollars. This is far less than we have spent on sending men to the moon. With energy production of such overriding importance to our nation, and even to the survival of man on this planet, there should he no question about fully supporting the fusion program. I t is clear that the sooner we find out about its feasibility the better, and half-way measures may very well find us with too little, too late, should political, economic, or technical difficulties further delay the hreeder. We stand now with the opportunity and the time to learn how to t a p this vast new energy source. The stakes -including world survival-are the highest, and the price is a bargain. Future historians would judge us rather harshly, I should think, if we failed to accept this challenge. Shakespeare, whose ancient hut immortal words keep reminding modem man that wisdom is timeless, expressed these thoughts well when he said There is a tide in the affairs of men which, taken at the flood, leads on to fortune: omitted. all the vovaee . of their life is bound in shallows and in miseries. 'on such a full sea are we now afloat and we must take the current when it serves or lose our ventures. ~
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