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I Nuclear reactors and nuclear bombs

  1. Sep 18, 2016 #1
    First, where does the STEAM get it's energy from? The only answers I'll find it the typical, silly, "e=mc2", "from the nuclear fission". Well, heat doesn't just magically GET RELEASED, it needs to be transferred somehow. My guess is that the neutrons and other radioactive materials released in the moderator transfer energy to it causing it to heat up. is that the case?

    Second, what's happening in an atomic bomb? yes a nuclear reaction occurs and mass is turned into energy, but what exactly causes that quick expansion and the red 'fire' that you see?

    Thank you in advance :D
  2. jcsd
  3. Sep 18, 2016 #2
  4. Sep 18, 2016 #3


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    Most of the released energy is in the fast fission products. They slow down and their energy gets converted to heat via elastic collisions in the material.
    Also heat: the bomb material gets extremely hot.
  5. Oct 16, 2016 #4
    Hi! I realize this is a little late, but energy from the fission is transferred to the primary coolant. Depending on the type of reactor, this coolant can be a few different types of substances, but because I am familiar with it, I generally think of it as pressurized, light water. The energy from the coolant is then transferred to the secondary system containing water. This is where the steam comes from! Fuel>Primary Coolant>Secondary Steam!
    There are MANY other parts to a nuclear reactor and its systems. Feel free to ask me any more questions!
  6. Feb 20, 2017 #5
    thank you for the information.
    in this real time,,what is more powerful than this nuclear weapon? and if there are how's it works? and if its possible turn into powerplans?
  7. Feb 21, 2017 #6
    There are links in the post #2, use them
  8. Feb 21, 2017 #7
    Yes, a nuclear power station generates power by very carefully controlling nuclear reactions.
    An exploding nuclear bomb is doing the same reactions, but in that case there is intentionally no control at all.
  9. Feb 21, 2017 #8


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    The person or country that owns it. (obviously I don't understand what you mean by "this" nuclear weapon).
  10. Feb 21, 2017 #9
    yes you are absolutely right about the persons and or country who owns it. but that is politically view. how about in scienctic view especially in physics sciential? and about "this" just ignore it.
  11. Feb 21, 2017 #10
    Science has nothing to say about politics.
    Any bomb is a device which causes damage.
    At best science can predict how much damage a bomb will cause in a given situation.
  12. Feb 22, 2017 #11


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    Well I didn't want to mention politics, just to make clear that the question was somewhat off... There's always the ability to make more powerful bombs than the already existing ones, but people don't actually need them. The gain is worse than the pay.
  13. Feb 22, 2017 #12


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    I'm not sure, but I think you are missing an important point. Nuclear particles flying around explain the chain reaction that releases the energy, but they are not the way that the energy is transmitted. Energy can be transmitted as electromagnetic radiation. That's how the Earth gets energy from the nuclear reaction in the Sun.
    Tremendous electromagnetic radiation heats everything around it and turns it to plasma.
    Last edited: Feb 22, 2017
  14. Feb 22, 2017 #13

    stefan r

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    Did you mean energetic or powerful?
    6.3×1013 J Yield of the Little Boy atomic bomb dropped on Hiroshima in World War II (15 kilotons)
    4.2×1015 J Energy released by explosion of 1 megaton of TNT

    700 GW – biomed: humankind basal metabolic rate as of 2013 (7 billion people).
    18.1 TW – tech: average total power consumption of the human world in 2013

    2.5 kilos of anti-matter has more energy than the largest nuclear blast. Total energy from the sun hitting earth in one second is close to that. So a big mirror might be what you are looking for. You can curve mirrors to heat a small area. Yes that can be turned into a powerplant or plan.

    A bunch of astronomy stuff is more powerful. Typical solar flare has more energy than several hundred million large nukes.
  15. Feb 25, 2017 #14


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    The thermal energy in a nuclear reactor or nuclear weapon comes from the kinetic energy of the fission products when a nucleus of a fissile species, usually an isotope of U, Pu or other heavy element, absorbs a neutron and fissions. Fission of U-235, where U-235 absorbs a neutron and becomes an excited U-236 nucleus, which then fissions (about 84% of the time) if it does not decay by gamma emission (about 16% of the time).

    In addition to the kinetic energy of the fission products, there are decay radiations, e.g., beta and gamma rays. The chain reaction refers to neutron production from fission. One fission produces 2 or 3 neutrons, and when a reactor is critical, at least one neutron must survive in order to produce a subsequent fission. Most of the energy from fission and decay is deposited in the fuel (about 2.5 to 3% of the energy is deposited in the coolant and structural material). The thermal energy is conducted to the coolant and then subsequently transferred through a steam generator to a secondary steam generating system, as is the case for a PWR, or the coolant can boil in the core of the reactor, as in a BWR. The steam is used to drive a steam turbine, which is connected to an electrical generator. There are also gas-cooled and liquid metal cooled reactors, and in order to produce steam, the thermal energy would have to be transferred to a water-based steam system. See Rankine cycle.

    In the case of a nuclear detonation, the energy release occurs in a matter of microseconds, and much energy is expressed as photons - from infrared to gamma radiation.
  16. Feb 25, 2017 #15
    The heat is coming from two sources, a little bit from the kinetic energy of the fission process, but mostly from decay heat, which is generated when the radiation created by the decay of the radioactive material interacts with other materials, such as the coolant within your reactor. This coolant, commonly water, is circulated through the system and around the core, and becomes quite hot during operation, until it is brought into the relatively cool steam chamber where its heat is leached off by the surrounding water and used to boil the water. When the water in the steam chamber boils, it creates a positive pressure within the steam chamber, which turns the turbine between the steam chamber and the condenser chamber and generates power. Once in the condenser chamber, the steam cools and converts back to water, which can then be pumped back into the steam chamber to be used again. It is surprisingly simple actually. Here is a picture.

  17. Feb 26, 2017 #16
    nice and interesting ,,,now I can more realized that how did the nuclear plant work. thank you and very appreciate
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