# "Thorium metal scrap" can explode? (1956 pic) **URL:** \ **Category:** Factual Questions\ **Created:** [August 7, 2026, 7:15pm UTC](https://boards.straightdope.com/t/thorium-metal-scrap-can-explode-1956-pic/1032217 "2026-08-07T19:15:15Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![Timz](https://avatars.discourse-cdn.com/v4/letter/t/6a8cbe/32.png) [@Timz](https://boards.straightdope.com/u/Timz)\ **Post date:** [August 7, 2026, 7:15pm UTC](https://boards.straightdope.com/t/thorium-metal-scrap-can-explode-1956-pic/1032217/1 "2026-08-07T19:15:15Z")
How did [this](http://digitalarchives.queenslibrary.org/browse/explosion-sylvania-electric-company) happen? What did Sylvania do with thorium? ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [August 7, 2026, 7:18pm UTC](https://boards.straightdope.com/t/thorium-metal-scrap-can-explode-1956-pic/1032217/2 "2026-08-07T19:18:18Z")
Thorium is highly flammable if it is finely powdered, or in small turnings. Maybe that’s what happened. ---
**Author:** ![Marvin\_the\_Martian](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/marvin_the_martian/32/2898_2.png) [@Marvin\_the\_Martian](https://boards.straightdope.com/u/Marvin_the_Martian)\ **Post date:** [August 7, 2026, 8:13pm UTC](https://boards.straightdope.com/t/thorium-metal-scrap-can-explode-1956-pic/1032217/3 "2026-08-07T20:13:02Z")
Thorium was a fuel used in some early commercial reactors: > **[Thorium-based nuclear power](https://en.wikipedia.org/wiki/Thorium-based_nuclear_power)** > > Thorium-based nuclear power generation is fueled primarily by the nuclear fission of the isotope uranium-233 produced from the fertile element thorium. A thorium fuel cycle can offer several potential advantages over a uranium fuel cycle\[a\]—including the much greater abundance of thorium found on Earth, superior physical and nuclear fuel properties, and reduced nuclear waste production. Thorium fuel also has a lower weaponization potential because it is difficult to weaponize the uranium-233 tha... Sylvania was involved in developing commercial-scale thorium fuel. ---
**Author:** ![Ancient\_Nerd](https://avatars.discourse-cdn.com/v4/letter/a/ed655f/32.png) [@Ancient\_Nerd](https://boards.straightdope.com/u/Ancient_Nerd)\ **Post date:** [August 7, 2026, 8:34pm UTC](https://boards.straightdope.com/t/thorium-metal-scrap-can-explode-1956-pic/1032217/4 "2026-08-07T20:34:19Z")
> [@Marvin\_the\_Martian](#): > > Thorium was a fuel used in some early commercial reactors: Richard Nixon made the call to focus on development of Uranium 235 for Nuclear power because a byproduct of the reaction is Plutonium 239 which can be used to make bombs. The Uranium design uses boiling water under pressure for cooling. The Thorium design uses a molten salt. ---
**Author:** ![gnoitall](https://avatars.discourse-cdn.com/v4/letter/g/bb73d2/32.png) [@gnoitall](https://boards.straightdope.com/u/gnoitall)\ **Post date:** [August 7, 2026, 8:47pm UTC](https://boards.straightdope.com/t/thorium-metal-scrap-can-explode-1956-pic/1032217/5 "2026-08-07T20:47:23Z")
> [@beowulff](#): > > Thorium is highly flammable if it is finely powdered, or in small turnings. > **[Pyrophoricity](https://en.wikipedia.org/wiki/Pyrophoricity)** > > A substance is pyrophoric (from Ancient Greek: πυροφόρος, pyrophoros, 'fire-bearing') if it ignites spontaneously in air at or below 54 °C (129 °F) (for gases) or within five minutes after coming into contact with air (for liquids and solids). Examples are organolithium compounds and triethylborane, as well as actinides. Pyrophoric materials are often water-reactive as well and will ignite when they contact water or humid air. They can be handled safely in atmospheres of argon or (with a fe The c... ---
**Author:** ![Isilder](https://avatars.discourse-cdn.com/v4/letter/i/cc9497/32.png) [@Isilder](https://boards.straightdope.com/u/Isilder)\ **Post date:** [August 11, 2026, 3:03pm UTC](https://boards.straightdope.com/t/thorium-metal-scrap-can-explode-1956-pic/1032217/6 "2026-08-11T15:03:56Z")
I couldn’t get to the OP’s URL . But the incident is this > **[Sylvania Electric Products explosion](https://en.wikipedia.org/wiki/Sylvania_Electric_Products_explosion)** > > On the morning of July 2, 1956, three explosions involving scrap thorium occurred at the Sylvania Electric Products' Metallurgical Laboratory in Bayside, (now Bay Terrace) Queens, New York. Nine people were injured, some severely. One 28-year-old employee, Oliver Blaber, died on August 6, 1956. Workers described three fireballs. Sylvania was experimenting with large-scale production of thorium metal from thorium dioxide. Part of the process of shutting down this experiment was the reprocessing a... ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [August 11, 2026, 3:24pm UTC](https://boards.straightdope.com/t/thorium-metal-scrap-can-explode-1956-pic/1032217/7 "2026-08-11T15:24:44Z")
Uranium, too, is highly pyrophoric. ---
**Author:** ![ASL\_v2.0](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/asl_v2.0/32/3525_2.png) [@ASL\_v2.0](https://boards.straightdope.com/u/ASL_v2.0)\ **Post date:** [August 11, 2026, 5:01pm UTC](https://boards.straightdope.com/t/thorium-metal-scrap-can-explode-1956-pic/1032217/8 "2026-08-11T17:01:50Z")
> [@Ancient\_Nerd](#): > > The Uranium design uses boiling water under pressure for cooling. The Thorium design uses a molten salt. That by itself could be a reason to prefer uranium. And of course you can create a liquid metal cooled reactor with uranium as well if you really want. It’s been done, even operationalized relatively early in the development of nuclear power: > **[S2G reactor](https://en.wikipedia.org/wiki/S2G_reactor)** > > The S2G reactor was a naval reactor used by the United States Navy to provide electricity generation and propulsion on warships, and the only liquid metal cooled reactor yet deployed by the US Navy. The S2G designation stands for: An S2G was the initial power plant of USS Seawolf (SSN-575). This was one of three sodium cooled reactors (the core was moderated) ordered for the Seawolf program at the same time as three PWR units were ordered to support the USS Nautilus (SSN-571) program; In each cas... [https://www.usni.org/magazines/naval-history-magazine/1992/march/technical-report-seawolfs-sodium-cooled-power-plant](https://www.usni.org/magazines/naval-history-magazine/1992/march/technical-report-seawolfs-sodium-cooled-power-plant) The USSR also used liquid metal cooled reactors, perhaps most notably on the Alfas. ---
**Author:** ![Ancient\_Nerd](https://avatars.discourse-cdn.com/v4/letter/a/ed655f/32.png) [@Ancient\_Nerd](https://boards.straightdope.com/u/Ancient_Nerd)\ **Post date:** [August 12, 2026, 7:14am UTC](https://boards.straightdope.com/t/thorium-metal-scrap-can-explode-1956-pic/1032217/9 "2026-08-12T07:14:32Z")
> [@ASL\_v2.0](#): > > That by itself could be a reason to prefer uranium. If something goes wrong and it gets too hot, the pressure of boiling water can increase to the point where it explodes. That is what happened at Fukushima. The molten salt is at atmospheric pressure. ---
**Author:** ![ASL\_v2.0](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/asl_v2.0/32/3525_2.png) [@ASL\_v2.0](https://boards.straightdope.com/u/ASL_v2.0)\ **Post date:** [August 12, 2026, 8:11am UTC](https://boards.straightdope.com/t/thorium-metal-scrap-can-explode-1956-pic/1032217/10 "2026-08-12T08:11:30Z")
> [@Ancient\_Nerd](#): > > If something goes wrong and it gets too hot, the pressure of boiling water can increase to the point where it explodes. That is what happened at Fukushima. That is not what caused the explosion at Fukushima. > The molten salt is at atmospheric pressure. Molten salt also has a nasty habit of turning solid if you can’t keep the temperature up. Which is not optimal for a coolant. I’d also imagine it has its own unique problems when it comes to radioactivity. Look, I will not pretend to be an expert on Boiling Water Reactors of the type they had at Fukushima or Liquid Metal Cooled Reactors. My experience is limited to a particular variety of Pressurized Water Reactors. But just from what you are saying here, I think you might have some misconceptions about nuclear power in general.