Tuesday, August 8, 2023

World's First Nuclear Reactor at the University of Chicago.

Construction of CP-1, or Chicago Pile Number One, was constructed under the University of Chicago's Stagg Field football stadium (1893–1957) in an abandoned squash court. Mankind first harnessed the energy of the atom on December 2, 1942. Fermi's pile produced only ½ watts of power. It constantly emits radiation.

Envisioned by famous physicist Enrico Fermi, CP-1 was a crude, ugly contraption of 330 tons of graphite bricks surrounding 5 tons of unrefined uranium metal. It had no shielding to protect the scientists operating it, but it was nonetheless a major breakthrough in developing nuclear weapons. Fermi successfully achieved a controlled atomic chain reaction.

Despite its crudeness, CP-1 was a major breakthrough in nuclear science. It showed that it was possible to produce a controlled nuclear chain reaction and paved the way for developing atomic weapons and nuclear power plants.

As the use of CP-1 improved, concern for the safety of its operators (and the thousands of nearby students) promoted a move a few miles to the west to the Cook County Forest Preserves, Lemont, Illinois, named 'Site A.'
Chicago Pile Number One or CP-1

The scientists dismantled CP-1, moved it to Site A, and reassembled it into a cube about 25 feet high and 30 feet on each base. This time, Fermi added a few safety elements. Five-foot concrete walls surrounded its sides. Six inches of lead and 50 inches of lumber acted as a lid.

Site A is about 20 acres in size and contains the buried remains of Chicago Pile-1.
Plot M is 150x140 foot (21K sq. ft.) area that is the radioactive waste dumpsite.

This redesigned reactor was named Chicago Pile-2 (CP-2). It was still a crude device but much safer than CP-1. CP-2 was used for research on nuclear weapons and other applications of atomic energy.

A year later, CP-3 joined CP-2. CP-3 was a more advanced reactor that used heavy water (H³O+) instead of graphite to slow nuclear reactions. CP-3 was used for research on nuclear power plants.
"World's First Nuclear Reactor," followed by a summarized history of Argonne. Photo: Forest Preserves of Cook County, IL.

For a decade, scientists conducted hundreds of experiments using these primitive reactors. The experiments ranged from nuclear weapons to biomedical research to sustained atomic energy.

The work at Site A and Argonne National Laboratory (which grew out of the Metallurgical Laboratory at the University of Chicago) laid the foundation for the development of nuclear science and technology. 

The two reactors, CP-2 and CP-3, were shut down in 1954. The most radioactive and dangerous elements of the reactors were disposed of by the Oak Ridge Laboratory in Tennessee. 
U.S. Department of Energy, 1974.

The reactor was buried in 1954 an extremely deep hole, and the surrounding area was designated as a radioactive waste dumpsite.

In the 1940s and 50s, visitors to the Red Gate Woods often encountered well-armed military police. The MPs would question the confused strangers, check IDs, and search pockets. Then without an apology or explanation, the confused visitors would be ordered firmly to leave the area and not return.

In the early 1980s, amid the nuclear disasters at Three Mile Island and Chornobyl, the City of Chicago asked Greenpeace surveyors to test the burial grounds at Site A. The surveyors were horrified to find islands of radioactive elements dotting the Site. The City requested help from the federal government, but their request was denied. However, when the information about the radioactive contamination went public, there was an outcry from the community. People who had spent years strolling, picnicking, and riding horseback in the woods near Site A were outraged to learn that they had been exposed to dangerous radiation. 

The federal government eventually gave the City $30 million to fence off, analyze, and decontaminate the Site. A decade later, their efforts transformed Site A into a safe, recreational area where people can enjoy the outdoors without fear of radiation exposure. However, the Site is still monitored annually for radiation levels. 

The Legacy of Site A and Plot M is foremost a reminder of the early days of the nuclear age. It's a testament to the ingenuity of the scientists who developed the world's first atomic reactor. And most importantly, reminds us of the dangers of nuclear technology.

In 1976, the public learned there was radioactive material in Red Gate Woods (Site A). The United States Department of Energy (DOE) released a report that found low levels of tritium in three wells in the area. Tritium is a radioactive isotope of hydrogen that is produced by nuclear reactors. The DOE concluded that the tritium likely came from Site A, which had been used for atomic research during World War II.

The DOE's report sparked a public outcry. The Illinois Department of Public Health (IDPH) conducted its own investigation and found that the wells' tritium levels were elevated but posed no immediate health risk to the public. However, the IDPH recommended that the DOE take steps to further study and clean up the Site.

The DOE continued to study Site A in the years that followed. In 1994, the DOE and the Argonne National Laboratory (ANL) began a significant cleanup effort at the Site. As part of the cleanup, 500 cubic yards (135 tons) of radioactive waste was removed and sent to the Hanford Site for disposal. By 2002, the IDPH had determined that the remaining materials posed no danger to public health.

Today, Site A is a fenced-off area within Red Gate Woods. There are signs in the parking lot that warn visitors about the radioactive material on the Site. However, the IDPH has determined that it is safe for people to visit the area as long as they stay on the trails, do not disturb the soil, and, most importantly, DO NOT DIG.

Compiled by Dr. Neil Gale, Ph.D.

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