The 1950s was a busy decade for nuclear power and safety research. The commercial Light Water Reactor (LWR) industry has its roots with the research performed in parallel by the AEC and U.S. Nuclear Navy. The Advisory Committee on Reactor Safeguards review the activities both to assure the safety of these projects. The government maintained tight control over atomic information. This became a hinderance to advancing this technology and with Eisenhower's Atom's for Peace speech, the veil of secrecy of this knowledge began to be lifted.

The Advisory Committee on Reactor Safeguards

To oversee the safety aspects, the AEC established the Advisory Committee on Reactor Safeguards (ACRS) in 1948. In the beginning the ACRS was strictly an advisory body with no statutory authority; however, in 1957, as the result of a very public rift between the ACRS and the AEC, this was changed.
Dr. Edward Teller was appointed the committee's first chairman. ACRS defined their purpose as an instrument towards preventing any future loss of life, particularly with regular industrial operations. The committee believed that there was no alternative to extreme caution - particularly, given that the images of the aftermath of WWII where still on the minds of all people, a single accident in an industrial nuclear reactor could wreck hopes for the peaceful atom. Their service to the AEC was to review every proposal for a reactor. Each proposal required a special evaluation that provided answers to two questions: What is the maximum credible accident? What are the consequences of a maximum credible accident?

To answer these questions, the ACRS heeded the lessons learned from the Industrial Revolution - that the total engineering reality is the reactor itself; hence, the final guide toward safety had to be experience in actual use. Therefore, the ACRS proposed to the AEC that they establish, in a deserted location, an experimental facility where scientists and engineers could cause nuclear reactors to malfunction in practically any manner imaginable. The AEC's initial response was skepticism; however, the arguments eventually prevailed and the National Reactor Testing Station was established in Idaho in 1949.

The destruction of reactors in Idaho could only represent part of the solution of reactor safety. The main difference between the Idaho reactors and a real reactor accident is that in the latter a lot of radioactivity would accumulate, a condition very difficult to reproduce. Real cases never can be mocked-up in a completely faithful manner. There must be three solid bases for confidence: careful calculation, observation of the contrived malfunctions, and thorough discussion correlating the two.

To the frustration of many ACRS members, the mandate of the Atomic Energy Act of 1946 to uphold the secrets of the atom slowed real progress for a peaceful atom. In addition, Dr. Teller expressed his opinion that without openness in revealing knowledge and potential dangers of nuclear energy, public acceptance would be weak. Such openness would have to wait a few more years. In the meanwhile real progress would become responsibility of the Department of the Navy.

A Vision for a New Navy

The Navy's goal was much more focused - to develop a nuclear propulsion plant. Westinghouse was awarded a huge contract to begin the development and ground was broken in the spring of 1950 at the Bettis Atomic Power Laboratory outside of Pittsburgh, Pennsylvania. Not to be left out, General Electric was later awarded a similar contract at the Knolls Atomic Power Laboratory (KAPL) near Schenectady, New York. Given that this project was first of kind, the Westinghouse and GE teams would face many technological challenges.

The basic concept of nuclear propulsion sounds simple - just put enough uranium, enriched to the proper amount of the fissile uranium-235 isotope, into fuel elements; and the fissioning of the uranium will produce heat. Drive a coolant over these hot fuel elements to generate steam that will then drive a turbine, which turns a propeller shaft. The accelerator for this engine would be control rods for adjusting the fissioning rate.

Despite this seemingly simple design, many decisions had to be made. The key safety issues for the Naval and Bettis teams were system reliability and radiation shielding. While not an obvious safety issue, the reliability of a naval propulsion system becomes a safety issue if a failure means lives are stranded in a hazardous or hostile environment.

The first big decision for the Navy was to be the choice of reactor coolant. Three options were available: pressurized water, helium gas, and liquid sodium. The gas option was thrown out early because of its low specific heat, its availability, and its containability; however, a "beauty contest" began between pressurized water and liquid sodium. Bettis forged ahead with the pressurized water reactor (PWR) and KAPL worked on the liquid sodium Submarine Intermediate Breeder (SIR) project. While KAPL did eventual complete the "Seawolf" submarine (1957) with a SIR installed, Admiral Hyman Rickover was uncomfortable with the design primarily over the concern that a leak of liquid sodium might make contact with water which would lead to an explosion. Hence, the Bettis PWR was adopted for Rickover's navy.

Early on it became clear to Rickover that to do the job right, a prototype had to be built. The AEC provided 400,000 acres of the National Reactor Testing Station (NRTS) in Idaho. Rickover was very aggressive to build a machine in a very short time. By mid-1952 the design of the Mark I plant was frozen and in March of 1953, the Mark I reactor went critical. A few months later it would reach full power.

Unveiling the Atom for Eisenhower's Atoms of Peace

If commercial nuclear power has a birthday, it was December 8, 1953. That was the day President Dwight Eisenhower gave his "Atoms for Peace" speech. In that speech he proposed the establishment of the International Atomic Energy Agency for the purpose of devising "methods whereby this fissionable material would be allocated to serve the peaceful pursuits of mankind. Experts would be mobilized to apply atomic energy to the needs of agriculture, medicine and other peaceful activities. A special purpose would be to provide abundant electrical energy in the power-starved areas of the world."

Shortly after Eisenhower's speech, the U.S. Congress passed the 1954 Atomic Energy Act. This legislation permitted for the first time, the wide use of atomic energy for peaceful purposes. The Act essentially ended the government's monopoly on technical data and began efforts to support the growth of a private commercial nuclear industry. Specifically, the AEC was "to encourage widespread participation in the development and utilization of atomic energy for peaceful purposes." The Act also assigned the AEC three major roles: to continue its weapons program, to promote the private use of atomic energy for peaceful applications, and to protect public health and safety from the hazards of commercial nuclear power.

At that time U.S. officials view the development of peaceful uses of nuclear power as an issue of national security. Other countries had begun this advancement and some believed that power hungry countries might align themselves with the USSR if it won the nuclear power race.

Shortly after the 1954 Atomic Energy Act went into effect, Duquesne Light Company was given permission to pursue the design and construction of what would become the first "commercial" nuclear power plant (this plant was built and owned by the government and operated by Duquesne). Shippingport, Pennsylvania was the site chosen and ground was broken in September 1954. The contractor for this reactor was Westinghouse; which relied heavily on the experience their engineers and scientist had gained through the work on the Naval projects.

Safety Research in Full Swing

To accomplish the goals outlined in the 1954 Atomic Energy Act, the AEC had to aggressively expand the understanding of the atom and an acceptable reactor design. This prompted a huge expansion in nuclear research both domestically and around the world. While the uncertainty of discovery lead many researchers to follow fruitless ideas, the focus of safety research eventually converged on the following topics:

[A synopsis of the significant research and accomplish of this period can be found by expanding the bullets to the left of each subject.]

During this decade a large number of reactors were built specifically for safety research. The table below outlines the landmark reactors and their contribution to safety research.

During this decade a large number of reactors were built specifically for safety research. The table below outlines the landmark reactors and their contribution to safety research. Expand the table entries for more information about these reactors by clicking the reactor name.

Major Reactor Projects of the 1950s

December 20, 1951 The Experimental Breeder Reactor - 1. World's first usable amount of electricity from nuclear energy
June 2, 1952 The Zero Power Reactor. First power reactor criticality accident - over exposes four people.
March 31, 1952 The first reactor built expressly for testing reactor core and fuel materials achieved startup on March 31, 1952.

March 30, 1953 The initial power run of the prototype reactor (S1W) for the first nuclear submarine, the Nautilus, was conducted.
July 22, 1954 First destructive test of a reactor results in a partial core melt
Fall 1954 Built to test transient performance of boiling water power reactors.
June 9, 1955 Destructive test program continues. Reactor also produces electricity for the town of Arco, Idaho.
  Built for experience with operating power plant.
  Built for experience with operating power plant.
June 11, 1955 Built to follow up BORAX experiments
Dec 1, 1956 Experimental Boiling Water Reactor achieves criticality
Feb 23, 1959 Transient Reactor Test Facility goes critical. Used to study the effects of simulated reactor accidents on fuel and components.

Shakedown for Commercial Nuclear Power

No doubt the early success of nuclear power research sponsored by the AEC paid off a quick dividend in the form of the worlds first nuclear power system; however, the reward would only be for the U.S. Department of Defense. For the technology to make the leap from a special government project to the private citizen took some politicking and good timing. The politicking came from nuclear powers number one proponent - Admiral Rickover. His original goal was the development of a large nuclear power system capable of servicing a vessel the size of an aircraft carrier. The Department of Defense had approved this project and work began in 1953; however, DOD officials later decided the price tag was too high and cancelled the project.

Rickover's plan to one day see the Navy's capital ship powered by nuclear energy was in jeopardy. A determined Rickover had to set a new course to achieve his vision. His first goal was to oversee the development of a reactor large enough to power the navy's largest vessels. DOD had rejected this plan; however, President Eisenhower was making overtones with respect to his coming "Atom's for Peace" speech. Rickover had his "in." If, as Eisenhower had suggested, the atom would one day be harnessed to benefit mankind, why not now? Afterall, the pressurized water reactor was a proven technology!

With this argument, Rickover approached the AEC and the Joint Committee on Atomic Energy (JCAE) to sell them on the idea of a pressurized water central power station. Other issues surfaced in this debate. For the proponents there was the fact that 1) billions had been spent on nuclear energy-related research for producing weapons and warships and nothing for peaceful venture, 2) Britain had already began such a project, and 3) we need to stay ahead of the Russians. For the opponents there was 1) the concern that Rickover's pressurized water reactor was not the best choice, 2) the project would still have military overtones (Rickover himself), and 3) no regulation suitable for a commercial scale plant had been formulated. In light of recent events, Rickover successfully sold the idea. In 1954 the U.S. Congress passed the Atomic Energy Act of 1954 to define the conditions and assign authority to permit the privatization of nuclear power.

The AEC put out a Request for Proposals on what would be a joint AEC/vendor/utility project. Of the nine proposals, it was the one from Duquense Light Company of Pittsburgh that was chosen. They would team up with Westinghouse and Bettis to build a central station near the town of Shippingport near Pittsburgh. In September of 1953 ground was broken at Shippingport in dramatic fashion with the wave of an "Atomic Wand" from President Eisenhower over a Geiger Counter that was used to send a signal over a telephone line to an unmanned bulldozer positioned to dig. On December 23, 1957, less than four and a half years after the construction contract had been signed, the Shippingport nuclear power plant reached full power and was providing electricity to Pittsburgh.

The Shippingport reactor was originally design to output 230 MW thermal, 60 MW electric; however, design features were included to increase output to 100 MW electric. The reactor core was composed of both highly enriched and natural uranium fuel elements assembled into a right-circular cylinder. The active portion of the core was about six feet high and about six feet seven inches in diameter. The core was of the seed-and-blanket design - over 24 assemblies containing over 1900 highly enriched uranium fuel elements (seed) were intermixed with assemblies containing the remaining 95000 natural uranium fuel elements. Primary coolant at 2000 psia was carried into the reactor vessel by 3 or 4 loops depending on the power level. Design steam pressure was set at 600 psia - the highest reasonable figure for existing reactor technology at that time.

Westinghouse was not the only player poised in the creation of nuclear industry. General Electric's involvement with its relationship with Knolls Atomic Power Laboratory and Argonne National Laboratory also was preparing to enter this new industry. While Westinghouse was first to break ground on large-scale nuclear power the citizens of Pittsburgh, General Electric cornered the first commercial nuclear power plant order from the Commonwealth Edison Company of Chicago. This would become the Dresden Station. However, before breaking ground on that project they believed that a small development plant was needed to assure the success of the full-scale Dresden plant. This development plant would become the Vallecitos Boiling Water Reactor. Ground was broken in June 1956 and would be completed by June 1957. Even though the Shippingport project had all the resources of the U.S. government behind it, it was the Vallecitos plant that received Power Reactor License No. 1 by the AEC.

The Vallecitos BWR was a much smaller project than Shippingport. It had a designed power output of 20 MW thermal to turn a turbine producing 5 MW electric. The thermal power was later increase to more than 30 MW. The reactor core originally contained plate-type enriched uranium fuel elements configured into a 3 ft by 3 ft right-circular cylinder. The VBWR was unique in that it could operate with both a direct (steam deliver directly to turbine) or dual cycle (reactor heat is transferred to a secondary system via a steam generator). In addition, the system design was conducive to both forced and natural circulation.

The technical objective of both Shippingport and Vallecitos was threefold:

1) To serve as a tool for the development, demonstration, and testing of reactor designs, cores, controls, and associated systems and components.

2) To provide a training ground in the construction and operation of boiling water reactors and aid in the development of experienced engineers and technicians essential to the construction of nuclear reactors.

3) To provide reliable information concerning load response characteristics, safety and fuel economy and to provide an operating prototype which can be used to demonstrate actual performance of a nuclear power reactor.

Both Westinghouse and General Electric gained a considerable amount technical expertise with their first venture into commercial nuclear power. They would both be able to build on this expertise as the first of many orders began coming to the two vendors. For GE they would spend the rest of the 1950s supporting the Dresden reactor project, for Westinghouse, they would get their first order from the Yankee Atomic Electric Company. Both companies would finish these reactors during 1960.

With the construction of these two plants began an important evolution in the safety culture for the nuclear power industry - the public hearing. By mandate of the U.S. government, the public was given a 30-day period during which people could intervene and ask for a public hearing. For a democratic society this is an important forum for airing opinions and concerns. The rules for calling a public hearing basically permitted anyone to call a public hearing following any change in the licensing application. The naivete of this young industry would later get burn by this procedure as professional "interveners" figured out how to exploit the public hearing process to delay construction and raise the price tag. However, in the early years of commercial nuclear power, the public hearing process was an integral mechanism for communicating with the public.


1) J. W. Simpson, Nuclear Power from Underseas to Outer Space, American Nuclear Society, La Grange Park, Illinois, 1995.

2) T. J. Thompson and J. G. Beckerley, The Technology of Nuclear Reactor Safety, Volume 1, MIT Press, Cambridge, Massachusetts, 1964.

3) A. W. Kramer, Boiling Water Reactors, Addison-Wesley, Reading, Massachusetts, 1958.

4) E. Teller, Energy from Heaven and Earth, W. H. Freeman and Company, San Francisco, 1979.

5) WASH-740, Theoretical Possibilities and Consequences of Major Accidents in Large Nuclear Power Plants, United States Atomic Energy Commission, March 1957.

6) "Operational Power Reactors," Nucleonics, September, 1955.


7a) "Controlling the Atom: The Beginnings of Nuclear Regulation, 1946-1962, University of California Press, 1984.