CP-1 at 80: The events of December 2, 1942

December 1, 2022, 12:01PMNuclear News

On the eve of the 80th anniversary of the first controlled nuclear chain reaction, Nuclear Newswire is back with the second of three prepared #ThrowbackThursday posts of CP-1 coverage from past issues of Nuclear News.

On November 17, we surveyed the events of 1942 leading up to the construction of Chicago Pile-1, an assemblage of graphite bricks and uranium “pseudospheres” used to achieve and control a self-sustaining fission reaction on December 2, 1942, inside a squash court at the University of Chicago’s Stagg Field.

Today we’ll pick up where we left off, as construction of CP-1 began on November 16, 1942.

CP-1 at 80: Preparing for the first controlled nuclear chain reaction

November 17, 2022, 3:08PMNuclear News
From left, the cover of the December 1962 issue of NN, featuring a model and a medal, both displayed at the 1962 ANS Winter Meeting; a photo of CP-1 during construction, as published in the November 1992 issue of NN; the opening page of a chronological account of CP-1, published in November 1992 to mark the 50th anniversary.

As we approach the 80th anniversary of controlled nuclear fission, Nuclear Newswire is prepared to deliver not one but three #ThrowbackThursday posts of CP-1 highlights unearthed from past issues of Nuclear News.

ANS was founded in 1954, nearly 12 years after the first controlled nuclear chain reaction was achieved on December 2, 1942, inside a pile of graphite and uranium assembled on a squash court at the University of Chicago’s Stagg Field. By 1962, ANS was prepared to “salute the 20th anniversary of the first chain reaction” at their Winter Meeting, displaying a model of Chicago Pile-1 and presenting a specially cast medal to Walter Zinn, a representative of Enrico Fermi’s scientific team. Over the years, ANS has continued to mark significant anniversaries of CP-1 at national meetings and in NN.

A critical shift in low-dose radiation research and communication

July 2, 2021, 2:15PMUpdated December 30, 2021, 7:15AMNuclear NewsSusan Gallier
A hot cell at Argonne National Laboratory was used to demonstrate a process for purifying molybdenum-99, an important diagnostic medical isotope. (Photo: Wes Agresta/ANL)

The biggest impact of radiation in our lives may come not from radiation itself, but from regulations and guidelines intended to control exposures to man-made sources that represent a small fraction of the natural radiation around us.

Decades of research have been unable to discern clear health impacts from low levels of ionizing radiation, leading to calls for a new research program—one with a strategic research agenda focused on how the scientific understanding of the health effects of low doses (below 100 millisievert) and low dose rates (less than 5 mSv per hour) can best be augmented, applied, and communicated.