II will include the further development and engineering needed for the construction of the final plant and actual operation of the plant. The aqueous homogeneous reactor appears to have real promise for central station application for several reasons, including (1) the possibility of attaining a breeding ratio of unity or near unity resulting in low fuel costs; (2) inherent safety resulting from a negative temperature coefficient of reactivity; and (3) the possibility of a continuous fuel reprocessing obviating the plant shutdown time needed by solid fuel element reactors for refueling. These indicated advantages led to the setting up of the PAR project through an agreement signed by the two companies on July 25, 1955.

Under this agreement, P. P. & L. and Westinghouse each appointed a representative with authority to carry on the project with an appropriation of $5.5 million over the period ending in 1958.

Shortly after the project got underway, the Union Carbide Nuclear Co. became a third member of the team and assumed the responsibility for the chemical reprocessing and waste disposal studies.

The project is now composed of 75 engineers and scientists and 35 technicians, for a total of 110 technical personnel, in addition to which Carbide is to supply 12 man-years of effort.

PAR has, at Pittsburgh, extensive laboratory and testing facilities, including physical chemistry laboratories, slurry preparation laboratories, and a large operation area for setting up and testing prototype plant equipment. Through January 1957, expenditures for the project, including firm commitments, amounted to $3.2 million. This does not include expenditures made by Carbide or the substantial outlays by other companies doing development work for PAR on a customer service basis at no charge to PAR. It is now estimated that the entire $5.5 million allocated to the phase I portion of the program will be spent by January 1958.

The PAR project has to date concentrated on the single region reactor concept using a slurry mixture of uranium oxide and thorium oxide in heavy water. This approach dovetails with, but avoids duplication of, the work of Oak Ridge National Laboratory on the two-region concept, which is designed to use a core of uranyl sulfate solution surrounded by a thorium oxide slurry blanket. Before final decision is made regarding phase II the relative merits of the singleregion and two-region concepts will be evaluated.

The major technical feasibility questions which must be answered for a slurry-type reactor are (1) whether the slurry can be handled in the complicated mechanical and hydraulic systems required in such a plant, and (2) whether adequate components can be developed for use in such systems.

Our attack on the problem of handling slurries has been very intensive. The slurry needed for a single-region reactor consists of a mixture of about 250 grams of thorium oxide and 10 grams of uranium oxide per kilogram of water. If allowed to stand without any form of agitation the solid particles of thorium and uranium quickly settled to the bottom of the container leaving essentially pure

water above them.

Typical of the extensive development facilities, are 13 loops, operating or under construction, for testing the behavior of slurries under various operating conditions. By the end of 1957 about $1.3 million

will have been invested in such equipment. These loops vary in size; our largest installation is to be a 10-inch-diameter loop operating at 600° F., 2,000 pounds per square inch and a flow of 4,000 gallons per minute which is one-half the proposed design flow for one loop of the final plant.

Preliminary answers to many of the important questions of handling and use of such slurries in high-pressure systems have been obtained. We now have firsthand experience on how such systems act if circulation is stopped and the slurry allowed to settle on the pipe and component walls.

Similarly, tests have been carried out to determine how to drain such a system after shutdown and information obtained on how much flushing and redraining is necessary to obtain quantitative recovery of the fuel of thorium and uranium initially charged into the loop.

The results from all of these tests have been uniformly encouraging, and strongly support the feasibility of actual powerplant operation. Even though much needs to be done on the properties of slurries under radiation, we now feel that for relatively pure slurries we can solve the handling problems facing us.

A special high-pressure and temperature slurry circulating loop to be placed in the new Oak Ridge research reactor in 1957 (ORR) is now being fabricated. This program is being jointly sponsored by ORNL and PAR to determine the effects of reactor irradiation on the behavior of slurries.

The second area of concentrated development work is the design and testing of components for use in slurry systems. Such equipment must be designed to meet two very unusual requirements. Flowing slurry may settle and clog equipment, also all equipment will become very radioactive as a result of plant operation. Therefore, the equipment must be designed so that repair or replacement work can be carried out by remotely operated tools.

The component development program was set up along three distinct lines. First, facilities and experiments were developed for testing prototype equipment such as circulating pumps, valves, makeup pump, heat exchangers, and instrumentation. Second, feasibility design studies of components for the full-scale plant were started either within Westinghouse or other manufacturers of large equipment. Third, steps were taken to deal with special problems of remote maintenance.

As regards prototype development purposes, four test loops have been constructed and tested in conjunction with valves, pressurizers, instrumentation, letdown devices, and various types of pumps.

As regards feasibility analysis of the construction of full-scale components, the best example of this type of activity is the design of the pressure vessel. Preliminary work indicated this vessel should be 10 to 15 feet in diameter and capable of withstanding a design pressure of 2,500 pounds per square inch. At the start of the project, it was not clear that equipment large enough to fabricate such a vessel was available anywhere in the entire country. As a result of design studies made for the PAR project by several pressure-vessel manufacturers, we have now determined the manufacturing feasibility of such vessels and are proceeding on the detailed design. Similar studies are well underway on most of the other major components of the final plant.

The remote maintenance of this equipment is also being examined in detail. As mentioned previously, once the plant has been operated, all the primary system components and piping become intensely radio active and cannot be approached by personnel for even the shortest period of time. This means that if a piece of equipment is to be re moved and replaced, it must be done using heavy-duty mechanical hands, remotely operated cranes, television equipment and special tools designed for the particular task. It must be remembered that the equipment being handled in this case is large, full-scale equipment and not laboratory-scale components. The feasibility of carrying out such tasks on a practical basis is a major question that must be answered before any large homogeneous reactor plant can be built A large maintenance demonstration facility is now being designated to determine experimentally that such components can be disassembled and repaired using only remotely operated tools. It is intended that once such techniques have been developed they will be tested by actu ally maintaining the large loop completely remotely.

In addition to this work, we have been doing considerable plant engineering. We have undertaken preparation of a series of overall reference designs to determine the nuclear design of the reactor, nec essary flowsheet data and physical layout of the plant. The purpos of these reference designs is to provide some guide in estimating ranges of capital costs. Our first design has been completed; the second is underway and we expect to finish the third by the end of phase I.

Our present outlook on estimated power costs is covered by the full statement I have already filed with the committee on pages 17 to 19 of that statement.

The results of our plant engineering work have been both encourag ing and discouraging. The detailed reference designs have indicated that many of the auxiliary systems needed for this type plant ar considerably more complicated than previously assumed. On the other hand, the results of our development program on the corrosion erosion of materials by slurries indicates our initial design parameters for slurry velocity were probably much too conservative and as a result our primary system piping can be decreased in size.

In summary, the PAR project has grown from an infant organiza tion in August 1955 to a relatively large development and engineering group. After approximately 19 months of concentrated effort, we feel that we have made definite progress. We must recognize, however that we are looking ahead to the unknown. Many unsolved problems and a tremendous amount of work lie ahead. In proceeding with the project, all of us hope that we will bring this research and develop ment program to a successful conclusion.

The CHAIRMAN. Dr. Shoupp, your statement is somewhat enlight ening. I believe you are the first witness to appear before this com mittee and discuss, in a technical manner, the type of reactor that you are building and trying to get into operation.

Mr. Van Zandt?

Representative VAN ZANDT. Doctor, where is this project located! Dr. SHOUPP. The technical work on the project is being done at the laboratories of the Westinghouse Electric Corp., in Pittsburgh, Pa. Representative VAN ZANDT. Why did you select this type of a

reactor?

Dr. SHOUPP. The reactor appeared to us, after our original investigation, to offer prospects of economic nuclear power.

The prime interest to us that led us to this speculation was the reduced fueling cost for this type of reactor, since it avoids the fabrication of the solid-fuel elements.

Representative VAN ZANDT. Can you give us some figures on the

cost?

Dr. SHOUPP. Well, I wish that I could. This is just what we are in process of determining in our phase I program. Our phase I program is set up to do enough preliminary design and analysis to enable us to get these preliminary costs.

Now, we work on cost data every day, but we do not have enough of them to add up to provide a cost number.

Representative VAN ZANDT. Can you make a guess, comparing on a percentage basis, the cost of the slurry of uranium as fuel, as against the solid fuel?

Dr. SHOUPP. Well, now, some of the uncertainties in these fueling costs are just the way that the uranium itself would be handled. You remember, here, that we have a mixture of uranium and thorium in this machine, and we start out with a large amount of highly enriched uranium. As time goes on, we burn this highly enriched uranium and make uranium 233 from the thorium. So the cost of the thorium and uranium and the credits for uranium 233 are very difficult for us to determine. But we hope-and it is our objective, not necessarily realizable to obtain a breeding ratio of 1. This means we hope to create as much uranium 233 as uranium 235 we destroy or burn up in the reactor.

If this is the case, our primary costs will be the costs for rental of fuel. Costs for heavy water that we use in this reactor, of course, would also enter in. But the fueling costs should be comparatively low. Added to this is an unknown that we are trying to get our teeth into at the moment; namely, the operation and maintenance costs for such a plant and for such a reactor. This is something we just do not know at all now.

The CHAIRMAN. You feel that your process would be cheaper to operate than one where you have to reprocess the solid fuel; is that right?

Dr. SHOUPP. Yes. We will still have to reprocess the fuel in this type of plant. However, herein is one of the big advantages of this type plant. We hope to be able to do the reprocessing on site. Now, we are studying the feasibility for shipping the burned fuel away and reprocessing it, but it appears to us at the moment that the reprocessing plant should be located on site.

The costs of doing the processing are very difficult to come by, because they vary enormously with the size of plant as well as with the many technical considerations involved. These reprocessing costs for this type of plant, even though they are, I think, much simpler than in the solid-fuel case, are still unknown.

The CHAIRMAN. Where do you test your fuels?

Dr. SHOUPP. Where do we do the testing of our fuels? Under irradiation, sir?

The CHAIRMAN. Yes.

Dr. SHOUPP. Well, under irradiation, to my knowledge, no one has yet operated a flowing slurry loop in a reactor. We work very

closely with the Oak Ridge National Laboratory and we are planning to put into the Oak Ridge Research reactor the first flowing slurry loop as a joint project with the Oak Ridge National Laboratory. I would like to ask Dr. Johnson precisely when the loop is to go into

service.

Between September 1 and January 1, I believe, we will have the first operating slurry loop in a reactor.

Now, the tests other than radioactive, which are probably more complicated than in the radiation case, are being done on the slurries in our own laboratories in Pittsburgh. And a very large amount of effort is going on at Oak Ridge. However, the primary Oak Ridge effort is on the two-region homogeneous reactor, and our work em. phasizes the one-region reactor. There is a considerable mutual interest and a mutual crossflow of information. But we are doing quite different jobs that only partially overlap.

The CHAIRMAN. Are you receiving full cooperation from the Laboratory?

Dr. SHOUPP. We are receiving excellent cooperation at the Oak Ridge National Laboratory.

Representative VAN ZANDT. Doctor, can you got into a little more detail as far as phase I is concerned?

Dr. SHOUPP. Yes. Phase I is to determine the feasibility of contin uing the detailed engineering and construction of the final plant.

At the end of phase I, we would expect ot be able to make roughly the following remark: that we have now determined that the plant can, or cannot, be engineered at that time. We will not know the solution to all our problems, but we know what the problems are, and we know that we can solve them.

The CHAIRMAN. You are not in a class alone.

Representative VAN ZANDT. The reason I asked the question, Doctor, was because I think you are making a very intelligent approach to this overall problem.

In regard to the financing, based on what you have said in your statement: $5.5 million has been made available for 1958, or to 1958. Dr. SHOUPP. Ending in 1958.

Representative VAN ZANDT. Do you have any program of financing the program for 1958, and beyond that year?

Dr. SHOUPP. Well, if the answer to phase I has been determined favorably--and it may come early in 1958, or it may come later-we then have plans for financing further development of this type of plant.

Possibly Mr. Busby would like to comment on that, from the Pennsylvania Power & Light Co. standpoint.

Mr. BUSBY. Well, we are in the process of trying to determine through phase I what is the basis of future action. And certainly as Dr. Shoupp has said, if the results of phase I, whenever that comes to its concluding point, are satisfactory, then that provides us with a basis for evaluating the program and, I should think, going ahead with the program.

Representative VAN ZANDT. Based on present-day costs, can you give us an ultimate cost of the plant?

Dr. SHOUPP. Well, again, this is just the information we hope to get a reasonable estimate for at the conclusion of phase I of the pro