TechBBN TECH
Uranium cubes show Nazi Germany's reactor fell short
A study in PNAS Nexus examined only two surviving cubes from the Haigerloch reactor, and found Germany's stocks of uranium and heavy water fell far short.
Watch it as it aired: Kenji Moonfield and Vera Bullock on this story, from BBN Newsroom at 2:09 PM ET. Cartoon anchors, real headline: the facts are ScienceDaily's, the jokes are ours.

At a glance
- First reported by ScienceDaily: “The uranium cubes that exposed Nazi Germany’s nuclear failure”.
- Covered on BBN on Tuesday, October 20, 2026, at 2:09 PM ET on BBN Newsroom, by Kenji Moonfield and Vera Bullock.
- Topics: Nazi Germany.
- BBN covered this story before: Still no Jets stream answer, but Schick keeps scoring in Germany (October 18).
The real story
The reporting behind this segment. The headlines belong to the outlets; read the original before you believe or share anything.
What BBN said about it

Vera Bullock · Co-AnchorSurviving uranium cubes and wartime documents show Nazi Germany never had enough uranium or heavy water to make its reactor work, ScienceDaily reports.

Kenji Moonfield · Internet & Trends CorrespondentThe reactor, called B8, held six hundred sixty-four uranium cubes hung on chains in heavy water, in a rock cellar in Haigerloch.

Vera Bullock · Co-AnchorResearchers estimate a working version needed about three point one tons of uranium, and B8 had roughly one and a half.

Vera Bullock · Co-AnchorThat's a strong foundation to build on.

Kenji Moonfield · Internet & Trends CorrespondentHalf the uranium, on chains. It's the world's worst hanging mobile.

Vera Bullock · Co-AnchorThe reactor's multiplication factor was calculated at zero point nine four. A chain reaction needs one.

Kenji Moonfield · Internet & Trends CorrespondentSo ninety-four percent of the way there?

Vera Bullock · Co-AnchorSomewhere a spokesman is saying zero point nine four is a chain reaction in beta.

Kenji Moonfield · Internet & Trends CorrespondentThe catch is that the study only examined two cubes, and one of them was found in a filing cabinet in two thousand eleven.

Vera Bullock · Co-AnchorSo the filing cabinet outperformed the reactor.
More Shorts
All videos →The story so far
- Nuremberg scare traced to a radio problem, not a hijacking · The Washington Times
- France and Germany seal EU car deal · Financial Times
- Germany: Running out of fuel on the autobahn can get you fined. · Wikipedia
- France, Germany strike bargain on Made in Europe, car emissions · POLITICO.eu
- Key player in false Talarico rumor has history of online posts… · The Guardian
- Still no Jets stream answer, but Schick keeps scoring in Germany · Yahoo Sports
- Uranium cubes show Nazi Germany's reactor fell short (this story)
From the archive: everything BBN aired on Tuesday, October 20, 2026 · the Tech archive · all months


Photo: Roger Templeman · CC BY-SA 2.0 · Wikimedia Commons · altered by BBN, shared under CC BY-SA 2.0
Photo: uncredited National Park Service employee · Public domain · Wikimedia Commons
Photo: Jensflorian · CC BY-SA 4.0 · Wikimedia Commons · altered by BBN, shared under CC BY-SA 4.0
Photo: USDAgov · Public domain · Wikimedia Commons · altered by BBN
Photo: Lyles BBQ, Smile and Learn - English, The Flat Top King… · Public domain · Wikimedia Commons · altered by BBN