Kodak Secretly Operated a Nuclear Device in Its Basement for Decades, and It Was a Marvel of Engineering

In a guarded basement of an office in Rochester, New York, a refrigerator-sized nuclear device quietly emitted neutrons for Eastman Kodak for three decades. But after it was shut down and hauled away, one of the employees mentioned it to a journalist. The news spread, editorial offices started getting alarming phone calls, and even CNN jumped on the story: Kodak had been using weapons-grade uranium deep within its labyrinthine research laboratories.

But the truth about the reactor was stranger and simultaneously less sensational than the headlines suggested.

The Birth of CFX

In 1975, Kodak launched the nation's first californium flux multiplier (CFX). While it didn't live up to the science-fiction expectations its name evoked, it employed a clever nuclear engineering trick to provide Kodak's R&D department with a sufficient neutron flux for materials analysis.

What CFX Was Used For

CFX served two purposes: neutron activation analysis and neutron radiography. The first allowed Kodak to test chemicals for impurities. When a sample is bombarded with neutrons, its elements form radioactive isotopes that emit gamma rays. Researchers could measure gamma ray energy levels to precisely determine a sample's composition.

Having such analysis capabilities on hand was convenient, but neutron radiography was practically a superpower for a private company. Although it works similarly to X-ray, neutrons interact with nuclei, while X-rays interact with electrons. This means that while X-rays are a powerful tool for examining heavy elements with many electrons, lighter elements and compounds such as water or film are washed out of images. With neutrons, it's different. If an X-ray shows a crack in a pipe, neutrons will show the leak.

How the Device Generated Neutrons

What was truly impressive was how Kodak's apparatus obtained its neutron flux. It used the spontaneous fission of californium-252 (Cf-252). This laboratory-made isotope emits neutrons the way a husky sheds fur in July. However, this neutron source was too expensive to use on its own in the apparatus (today it costs about $30,000 per milligram). So the CFX designers turned to a standard fission source: highly enriched uranium (HEU).

Neutrons came from a tiny Cf-252 source — about 3.1 milligrams at the core of the device — and passed through 52 plates of highly enriched uranium. Behind lead shielding, the neutrons collided with HEU atoms, forming unstable nuclei. Often, but not always, these would decay into lighter fragments, releasing an additional two or three neutrons in the process. By the time the flux reached the sample port, its intensity was 30 times higher than that of the Cf-252 alone.

Not a Reactor — Subcritical by Design

At first glance, this might seem surprisingly similar to a nuclear reactor: uranium fuel plates, fission neutrons, heavy shielding. The crucial difference is that the CFX was specifically designed to remain subcritical, so that each fission produced fewer neutrons than needed to sustain a chain reaction. Without the Cf-252 feeding it, the process dies out.

From 1975 to 2006, CFX operated within its half-meter-thick walls and in accordance with government-approved safety protocols. Approximately every seven years, the Cf-252 source was replenished. And, aside from a hiccup with license renewal in 1980, the device caused no stir until a local newspaper reported on its existence — it wasn't a secret, just not something anyone advertised.

The 2012 Media Storm

Unsurprisingly, when news of Kodak's CFX swept across the US in 2012, most media outlets focused on the danger of HEU rather than its ability to generate neutron flux. Indeed, it's hard to imagine that private corporations can be trusted with the material from which atomic bombs are made today. But CFX was installed during a period of nuclear optimism, when it was normal for leading universities to operate reactors, and ambitious companies sought to harness atomic energy.

According to Kodak and government officials, the CFX in its bunker was a strictly regulated, non-hazardous system. The greatest danger arose during decommissioning in 2007. The old CFX was the industrial lab equivalent of an asbestos-wrapped pipe in your basement. It's perfectly safe until you decide to get rid of it.

Decommissioning Challenges

And while the Cf-252 component weighed roughly the same as a snowflake, the HEU weighed a more substantial one and a half kilograms. And although building an atomic bomb requires approximately 45 kg of this material, there is concern that bad actors could collect enough small batches to build a weapon. Under the watchful eye of the Department of Energy, the plates were carefully transported to government storage. Security was maintained such that no public document indicates who exactly transported the plates or how they were moved using protocols involving tongs and plexiglass shields, which surprisingly do an excellent job of slowing down neutrons and the alpha radiation of HEU.

Legacy

The real story of Kodak's flux multiplier is more of a technical curiosity than a conspiracy. It was a brilliant Cold War-era engineering project, subject to strict government oversight and tucked beneath a corporate campus. Kodak has long since sold the building, and the space has long been declared safe, despite a few isotopes activated in the concrete. But it's a reminder that cutting-edge technology was once radioactive.