program for making periodic assessments of performance. Review of headquarters divisions' inspection programs continued.

Foreign Activities

Methods were developed for assisting execution of the safeguard provisions of agreements for cooperation between the United States and individual nations. Initial visits were made under this program.

Reactor Development

Substantial progress was made during the January-June reporting period on the Commission's programs to advance the technology of civilian and military power reactors.

Seven power reactor experiments were operating and the Shippingport Atomic Power Station, which was dedicated by the President on May 26, was operating at its full power of 60,000 net electric kilowatts. Major construction was started on the Experimental Breeder Reactor No. 2, the last of the experimental power reactors in the 5-year program approved by the Congress in 1954. Results of design studies were sufficiently promising to warrant continuing the development program on the liquid metal-fueled reactor, with construction planned. to start in 1959. A design study was initiated to evaluate the potential of gas-cooled power reactors using moderately enriched uranium. Facilities were under construction and others were planned to advance the work on using plutonium as a reactor fuel.

The fifth contract was signed in the industry-Government cooperative program calling for design and construction of prototype power reactors. Contracts for construction of two other reactors were being negotiated under the Power Demonstration Reactor Program, and bases of agreements on two others were before the Congress. Development work continued on a tenth reactor. One project was cancelled after studies showed it was not promising in the size proposed.

The keel was laid for the first nuclear-powered merchant ship, fabrication of its propulsion plant went forward, and other work was continued aimed at assisting introduction of nuclear-powered ships into international commerce.

General engineering and development continued in support of the reactor industry. After an extensive testing program, the Engineering Test Reactor began operating at its full design power. In the reactor safety program a 50 kilowatt test reactor reached a momentary power level of more than 500,000 kilowatts without sustaining damage.

Development and construction continued on reactors required for

various military applications, including production of power and heat at remote bases, and propulsion of naval vessels and of manned and unmanned aircraft. Three nuclear-powered submarines were operating and have steamed a total of 182,000 miles, 133,000 miles while submerged; one made a transatlantic voyage sub merged throughout the trip. An additional nuclear-powered submarine was launched and 18 were being built. In addition, a guided missile cruiser and an aircraft carrier utilizing eight reactors were being built.

CIVILIAN POWER REACTORS

Civilian power reactor work in the United States reached a new level of maturity during the last 6 months with experimental operation of seven reactor experiments, routine power operation of the Shippingport Atomic Power Station, and continued progress in the private and cooperative programs for construction and operation of full-scale nuclear powerplants.

The seven experimental reactors which operated are: Experimental Boiling Water Reactor (EBWR), Boiling Reactor Experiment No. 4 (BORAX-4), Homogeneous Reactor Experiment No. 2 (HRE−2), Experimental Breeder Reactor No. 1 (EBR-1), Sodium Reactor Experiment (SRE), Organic Moderated Reactor Experiment (OMRE), and the Vallecitos Boiling Water Reactor (VBWR). The Vallecitos reactor was built and is owned by General Electric Co; the others were wholly or primarily Commission financed.

The civilian power effort has definitely advanced to much firmer ground as a result of this encouraging operating experience and the direction of development required to achieve economic nuclear power can now be charted with more certainty.

Experimental Reactors

Shippingport Atomic Power Station. The Shippingport Atomic Power Station, the nation's first large-scale nuclear powerplant to generate electricity for civilian purposes, was dedicated on May 26 at Shippingport, Pa., the proceedings being carried on a nationwide television network.

President Eisenhower from the White House used a neutron source to send an impulse to Shippingport which opened the main turbine throttle valve of the plant to generate electricity from the 60,000 kilowatt plant for homes, stores, and industrial plants of the Pittsburgh

area.

In his remarks, the President said, "It is with pride in what has been accomplished at Shippingport-and with equal confidence in

the future that I now dedicate this Shippingport Atomic Power Station to the cause of scientific progress-the cause of peace.

"The plant represents what can be done, not only in America but throughout the world to put the atom to work for the good of mankind, not its destruction * * * It represents the hope of our people that the power of the atom will be able to open up a vast new world of peaceful development; that atomic power will ease mankind's burdens and provide additional comfort for human living."

In an address at the reactor dedication, Chairman Strauss said, "As the years pass, nuclear powerplants of greater size and even more sophisticated technology than this great plant will be completed. Some of them are far along in construction. Nevertheless, this Shippingport plant will always hold the proud title as the first of the world's large-scale nuclear power stations built and operated exclusively for peaceful purposes. The Duquesne Light Company, the Westinghouse Electric Corporation, and those who direct those great enterprises have performed a signal service to the nation. Their courage and their enterprise have made American industrial history."

The reactor first achieved criticality on December 2, 1957, 15 years to the day after the first experimental atomic pile built by Enrico Fermi and his associates attained a chain reaction. The Shippingport plant first produced electricity on December 18, and on a test basis it delivered 60,000 net kilowatts of electricity on December 23.

During the first 3 weeks of January, this pressurized water reactor plant was maintained in a subcritical condition but at operating temperature and pressure while various tests involving the performance of the core and plant systems were carried out. During the last week in January and the first week in February the plant was shut down for routine maintenance and to perform minor modifications.

Critical operation was resumed on February 5 for the performance of core physics tests. The plant was brought to power on February 10. During the remainder of February and the first 2 weeks of March the plant was operated at various power levels up to 60,000 kilowatts net electrical output, supplying power to the system of the Duquesne Light Co., which is operating the plant under contract to the Commission. Valve operating system tests, response of the plant to variation in load, neutron flux measurements, instrument calibration, and other operational and physics tests were successfully conducted in conjunction with power operation.

The third week of March was devoted to physics and control rod drive tests which involved both subcritical and critical operation. During the remainder of March and until April 28 the plant was again operated at various power levels supplying the Duquesne Light Co.

Shippingport dedication. Admiral H. G. Rickover, Chief of Naval Reactors Branch, Atomic Energy Commission; Lewis L. Strauss, Chairman, U. S. Atomic Energy Commission; Honorable Henry Dworshak, U. S. Senator (Idaho); James E. Van Zandt, U. S. Representative from Pennsylvania; Philip A. Fleger, Chairman of the Board, Duquesne Light Co. at the Shippingport Atomic Power Station during dedication ceremonies May 26, 1958.

system. Physics tests which required continuous high power operation were performed during the week of April 28.

As of June 30, the plant had delivered nearly 38 million net kilowatthours of electricity to the Duquesne system.

Boiling water reactors. Since the first Boiling Reactor Experiment (BORAX-1) demonstrated the basic stability of boiling water systems in 1953, the Commission has continued development of the BORAX series and BORAX-4 is presently in operation at the National Reactor Testing Station. Late in 1956, the Experimental Boiling Water Reactor (EBWR), a pilot-plant boiling water power reactor complete with turbine generator, began operation at Argonne National Laboratory. This was about a year and a half after start of construction.

469978-58-7

Recent operating results from the EBWR and BORAX-4 have been most encouraging. Among major results are the following: (a) The EBWR was operated stably at 62 thermal megawatts, more than 3 times its nominal design rating of 20 megawatts, without major modification. It is planned to operate this plant at still higher power levels after installation of a larger core and additional heat removal equipment. This large increase in power has been possible because the natural circulation of water in the core has been much greater than was once thought possible, and because the increasing amount of steam in the reactor core caused by the high power operation has not resulted in instability as was originally expected. In this connection, BORAX-4 operated stably with more than 7 percent of its total reactivity contained in steam voids the highest level yet achieved in a boiling water

reactor.

(b) Turbine maintenance in the EBWR has proved to be routine in spite of the fact that saturated steam is fed directly from the reactor to the turbine. There has been little or no pitting of the turbine blades and residual radioactivity in the turbine has been so low that direct maintenance is possible. Even under the severe test of experimental operation of EBWR and BORAX-4 with the ruptured oxide fuel elements, radioactivity carryover to the turbine was small. During routine experiments in early May, excessive vibration was detected in the EBWR turbine. A subsequent examination of the turbine revealed that one turbine blade and its shroud were broken loose from the rotor. This is believed to have been a fatigue failure which is not related to the nuclear portion of this plant. The necessary repairs have been made and operation of the plant has resumed.

(c) Experiments in BORAX-4 have demonstrated that boiling reactors can operate stably with uranium oxide or thorium oxide fuels. There had originally been some concern that the poorer heat transfer characteristics of oxide fuels as compared with metallic fuels would adversely affect reactor stability. Among the advantages of oxide fuels is their ability to withstand very high exposures at high operating temperatures. In event of a failure of protective cladding on fuel elements, they also are much less reactive with the water coolant than are metallic fuels.

These encouraging operating results have pointed the way to additional methods of improving boiling water reactor systems. Modifications in core geometry promise to increase the natural circulation of coolants beyond the high levels already attained and thereby increase their heat output. Forced circulation of the coolant is a