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.

 

Part I — The First Temple of the Atom: The AEC and the North Carolina State Research Reactor

Thomas Wellock
NRC Historian

 

In January 1955, Newsweek reported, “It is the envy of thousands of scientists and hundreds of college presidents. It has made Raleigh, North Carolina’s capital, an atomic mecca, attracting such disparate types as President Celal Beyar of Turkey, a band of junketing North Carolina peanut growers, some German school teachers, as well as a procession of industrialists from all over the world.”

https://www.lib.ncsu.edu/specialcollections/digital/text/engineAll had come to see the world’s first research reactor open for public view at North Carolina State College (NC State).

Proposed by NC State in 1950, the reactor was an audacious idea when the most basic information about the fission process was a Cold-War secret. Industry and universities were unwilling to pursue civilian applications of nuclear energy that required expensive security clearances.

Where others saw obstacles, Clifford Beck spied an opportunity. A physicist at NC State, Beck proposed to the Atomic Energy Commission the nation’s first nuclear engineering program built around a declassified reactor.

His timing was perfect. The announcement in September 1949 that the Soviet Union had exploded an atomic bomb tipped the debate within the AEC toward those who favored declassifying atomic secrets. Former AEC Chairman David Lilienthal called on the AEC to “free the atom” for U.S. industrial use.

AEC officials were elated with Beck’s proposal since it provided them with a concrete reason to declassify reactor information. They assured him they were “practically unanimous” that it would be approved. In late 1950, the AEC made public for the first time information on fission research and small research reactors, including the NC State reactor.

Taking advantage of its status as the world’s only public reactor, NC State included a viewing auditorium with thick water-shielded windows so the public could see nuclear energy was, as Beck claimed, “just another type of tool, not something mysterious and super-secret.” In the first year of operation, the reactor had more than 6,000 visitors who came to see a reactor that was “guarded by nothing more than a physics student with a guest book.” One intrigued journalist dubbed it “The First Temple of the Atom.”

NC State Observation Room
NC State Observation Room

Ending secrecy cleared only the first hurdle for NC State. The AEC had to confront difficult safety and security questions.

In 1950, the 1946 Atomic Energy Act strictly limited uses of fissionable material. How could the agency provide bomb-grade fuel to a civilian reactor? How could it prevent sabotage of an unguarded reactor? How could the AEC ensure safe operation on a densely populated college campus? And who in the AEC should approve the reactor?  In answering these questions, the agency foreshadowed many of the later practices it followed in licensing nuclear power reactors. We will turn to that story on Wednesday.

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