Trivia

Hard

The Interior Of Nuclear Reactor Cores Glow What Color?

Blue
Yellow
Red
Green
Cherenkov radiation glowing in the core of the Advanced Test Reactor.
Argonne National Laboratory/Flickr

Answer: Blue

Pop culture depictions of glowing green radioactive materials like the “ooze” in Teenage Mutant Ninja Turtles or the green glow of radiation at Homer’s nuclear reactor job in The Simpsons have done a remarkable job of cementing the idea in peoples’ heads that radiation is green, green, and more green.

So you might be very surprised to find out that the interior of a nuclear reactor doesn’t glow green at all, but an incredibly serene blue color that belies the danger found therein. The blue glow found in water-submerged nuclear reactor cores is called “Cherenkov radiation”, named after Soviet researcher Pavel Cherenkov, and is a form of electromagnetic radiation emitted when a charged particle passes through a dielectric medium at a speed greater than the phase velocity of light in that medium. In layman’s terms, the glow results from electrons freed during the nuclear reaction zipping along at very high speeds through the water.

Why blue instead of another color on the visible spectrum? Cherenkov radiation is very high frequency and the majority of it isn’t even visible to the human eye (but is in the ultraviolet range just outside the edge of the visible spectrum). The blue we see is the very lowest end of the frequency emitted by the reaction and, just over the frequency line, so to speak, from ultraviolet, and we see it as very bright blue.

Trivia

Easy

What Common Thing Was Known As “Devil’s Rope” Shortly After It Was First Created?

Trivia

Very Hard

This 1990s Television Show Ushered In The Era Of Sophisticated Title Sequences?

Trivia

Easy

Which Of These Colors Appears With The Highest Frequency In National Flags?

Trivia

Easy

Which Author Was Forced To Bring One Of His Beloved Characters Back To Life After Years Of Public Pressure?

Trivia

Very Hard

Which Of These Colas Was Originally Called “Brad’s Drink” Before Assuming Its Modern Name?

Trivia

Very Hard

The Best Selling Movie Soundtrack Of All Time Was For The Movie?

Trivia

Hard

The Country With The Most World Heritage Sites Is?

Trivia

Easy

Which Modern Day Actor Landed A Role Portraying His Very Distant And Famous Cousin?

Trivia

Very Hard

What Was The World’s First Code-Breaking Computer?

Trivia

Hard

What Was The Deadliest Airship Disaster Of All Time?