Nuclear Reactor Pulse

A Triga nuclear reactor getting supercritical! And I was standing up on the top of a nuclear explosion!

Category:

Science & Technology

Tags:

• nuclear
• reactor
• pulse
• explosion
• physics

[Garrett85]

E' un reattore nucleare didattico presso un università statunitense.

[riccardobevilacqua]

Tutto corretto quello che scrivi, Garrett85, tranne una cosa: il reattore dove ho girato questo video si trova a Vienna! (ma ce n'é uno uguale anche a Pavia, tuttora funzionante!)

[Gregiorp]

I dont get it what am I..(00:12)...WOAH AWESOME

[ApolloWasReal]

@wog222 Yes indeed. Reactors differ enormously in their various 'coefficients' - whether the reactor power tends to go up or down as it heats up, runs dry of coolant, etc. Chernobyl had numerous design flaws and incompetent operators unaware of the safety rules. It went supercritical and the power shot to ~100x normal. These research reactors have very strong negative temperature coefficients that make this impossible, but they're not useful for power generation for the same reason.

[wog222]

@ApolloWasReal That is cool - there is so much more to reactors then I ever would of thought. So if you pulse the wrong type of reactor you will have a bad day.

[ApolloWasReal]

@wog222 Many (but not all) reactors use water for yet another purpose: neutron moderation. That slows down the neutrons emitted from fission to make them more likely to trigger another fission. That's actually not the case in this research reactor; the moderator is the hydrogen in the uranium hydride fuel. The fuel heats it instantly, unmoderating and slowing the reaction. That's what makes pulsing this reactor safe. It'd be very unsafe in a reactor with a separate moderator.

[ApolloWasReal]

@wog222 Most nuclear plants are near large bodies of water (lakes, oceans, rivers) not because they need water to make steam for their turbines. That water is easily recycled. The real reason is to increase thermodynamic efficiency, the fraction of reactor heat energy that becomes electricity. The hotter the steam and the cooler the condenser, the greater that efficiency. Since about 2/3 of the reactor heat is still wasted, that's a LOT of cooling water!

[wog222]

@ApolloWasReal Thanks for your reply's. That is interesting to me that water is used for shielding and for cooling. Oh, and also steam. I assume that is why the nuke plants are near water.

[ApolloWasReal]

@wog222 The real hazard from both a nuclear reactor and spent nuclear fuel is their gamma radiation. They're photons, just like light and X-rays, except they're far more energetic than even X-rays. What makes them dangerous is that they're ionizing but not TOO ionizing. So it takes heavy shielding to absorb enough of their energy to protect people beyond. Fortunately, water is a very good shield that's also cheap, transparent and easy to store and move.

[ApolloWasReal]

@wog222 Beta particles are just energetic electrons. Any charged particle can be ionizing if it's energetic enough, as these are. That means it can rip up molecules like those in your body. Fortunately, beta particles are so ionizing that they quickly give up their energy when they hit something -- even air -- so they can't penetrate very far. So as long as the beta-emitting material is outside you it's not very dangerous. But if it gets inside you, then it can be pretty bad.

[ApolloWasReal]

@wog222 Beta particles are just energetic electrons. Any charged particle can be ionizing if it's energetic enough, as these are. That means it can rip up molecules like those in your body. Fortunately, beta particles are so ionizing that they quickly give up their energy when they hit something -- even air -- so they can't penetrate very far. So as long as the beta-emitting material is outside you it's not very dangerous. But if it gets inside you, then it can be pretty bad.

[wog222]

@ApolloWasReal are beta particles really "bad" to come in contact with?