Penn State University’s Breazeale Reactor Celebrates 60 Years

Thomas Wellock
Historian

pennstateLast month, Pennsylvania State University’s Breazeale Research Reactor celebrated its 60th anniversary as the nation’s oldest licensed reactor. The Breazeale reactor has been invaluable in research, training, and in establishing Penn State’s well-regarded nuclear engineering program. As part of the Atoms for Peace program, it trained foreign engineers as reactor operators and tested fuel integrity for reactors exported to other nations.

It is a historic marker of early reactor development.

In the early 1950s, universities raced to build research reactors. North Carolina State College jumped ahead when it contracted with the Atomic Energy Commission (AEC) to build a reactor that started up in 1953. By 1955, 14 schools had applied to the AEC for the license required of new reactors under the Atomic Energy Act of 1954.

Penn State had two important assets in this race: money and William Breazeale. Penn State’s board of trustees committed ample funds for construction and operation. To win AEC approval, Penn State followed NC State’s successful strategy of raiding the AEC for faculty talent and a reactor design.

An electrical engineer by training, Breazeale had worked for several years at Oak Ridge National Laboratory supporting the design of thorium and uranium-fueled reactors. His signal accomplishment was in leading the design team for the Bulk Shielding Reactor, the prototype of the “swimming pool” research reactors built at Penn State and facilities around the world. Penn State hired Breazeale to serve as its first-ever professor of nuclear engineering.

The swimming pool reactor was safe, inexpensive, and startlingly simple. Engineers just placed the reactor fuel at the bottom of a tank 30 feet deep so that the water served as a source of cooling and radiation shielding. Faculty and students could stand on a platform directly over the reactor to operate and view it.

Nevertheless, the AEC’s Advisory Committee for Reactor Safeguards (ACRS) made the path to licensing approval so challenging that a frustrated Breazeale once suggested the Committee did not “view the [reactor] hazard problem in its proper perspective.” It wasn’t the last time that ACRS safety concerns were challenged by applicants and vendors.

Earlier this month, NRC Chairman Stephen Burns (right) visited Penn State and toured the reactor. He's standing here with Kenan Unlu, Ph.D., Professor of Nuclear Engineering.
Earlier this month, NRC Chairman Stephen Burns (right) visited Penn State and toured the reactor. He’s standing here with Kenan Unlu, Ph.D., Professor of Nuclear Engineering.

The ACRS fretted over the potential for theft of the fuel, power excursions, and the proximity of the reactor to college housing. The reactor’s 3.6 kilograms of highly enriched fuel posed a safeguards risk, and the Committee demanded a combination of security guards and radiation monitors to protect it. Penn State had to carry out fuel test program and moved the reactor further away than planned from faculty housing. The ACRS also required an emergency plan for notifying local authorities, public evacuation, and cleanup.  Ironing out these issues delayed licensing. When President Dwight Eisenhower gave the college’s commencement address in June 1955, he could only look down into an empty tank with no fuel.

But persistence led to success. On the morning of August 15, Breazeale and doctoral student Robert Cochran started the reactor for the first time. Both veteran Oak-Ridge operators, their approach to criticality was careful but confident enough that they paused so that Cochran could run to the registrar’s office. At 11:30 a.m., the reactor went critical. Then Breazeale and Cochran shut down the reactor and stored the fuel in a vault for two weeks. It was, after all, summer vacation.

The Breazeale reactor reminds us how much reactor safety has changed while staying the same. Its 1955 license was just two pages of conditions. When Penn State renewed it in 2009, the license had grown to 60 pages. Safety regulation is more complex today, but the inherent safety of Breazeale’s reactor remains as important today as it was in 1955.

Part II: Ensuring Safety in the First Temple of the Atom

Thomas Wellock
NRC Historian
 

https://www.lib.ncsu.edu/specialcollections/digital/text/engineAs noted in Part I of this story on the NC State research reactor, the Atomic Energy Commission (AEC) was very anxious to promote the world’s first civilian reactor. But its enthusiasm was tempered by the challenge of placing a reactor safely on a busy college campus and developing an approval process for non-AEC reactors.

The AEC turned to its Reactor Safeguard Committee, the forerunner of today’s Advisory Committee on Reactor Safeguards. The Committee was formed in 1947 to evaluate the safety of new reactors proposed by AEC laboratories and contractors.  “The committee was about as popular—and also necessary—as a traffic cop,” recalled Safeguard Committee Chairman Edward Teller.

The Committee’s most significant contribution was establishing a conservative approach to safety given the engineering uncertainty of that era. “We could not follow the usual method of trial and error,” Teller said. “The trials had to be on paper because the actual errors could be catastrophic.” The Committee developed a “simple procedure” of challenging a reactor designer to write a “hazard summary report” that imagined the worst “plausible mishap”—soon known as a “maximum credible accident”—and demonstrate the reactor design could prevent or mitigate it.

Five NC Stte physics professors designed the reactor. Here, in the reactor control room (left to right front row) are Clifford K. Beck and Arthur C. Menius, Jr. Standing is Newton Underwood, three unidentified students, Arthur Waltner and Raymond L. Murray.
Five NC State physics professors designed the reactor. Here, in the reactor control room, (left to right front row) are Clifford K. Beck and Arthur C. Menius, Jr. Standing is Newton Underwood, three unidentified students, Arthur Waltner and Raymond L. Murray.

The Committee focused on several hazards, including a surge in the chain reaction called a reactor “runaway,” a catastrophic release of radioactive material from fire, sabotage, or an earthquake, and hazards from routine operation that might result from leaks or inadvertent exposures. The Committee asked NC State to address these concerns in a “hazards summary report.”

To meet the Committee’s desire for inherent safety, NC State proposed a “water boiler” reactor, which was believed to have “student-proof” safety margin given its strongly “negative coefficient” of reactivity that limited greatly the possibility of a runaway. NC State also developed interlocks and an extremely dense concrete shielding to discouraged sabotage.

In order for NC State to commit the funds to such a long-term project, it needed an early approval. This created a dilemma since the college did not yet have a detailed, complete design.  The AEC used a two-step conditional approval that was similar to its later construction permit/operating license process. In step one, construction did not begin until NC State addressed the most important design safety issues. When it did, the AEC agreed by contract to supply enriched fuel. The fuel was not delivered, however, until NC State resolved all outstanding safety questions and a final inspection took place. With that, the first civilian reactor in history went critical in September 1953.

The AEC approach to safety at NC State foreshadowed many later regulatory practices. As important as the 1954 Atomic Energy Act is to current regulatory practice, it is interesting to see that many of the critical elements have even deeper roots back toward the beginning of the atomic era.

 

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