# Nuclear Power for dummies - can someone explain? **URL:** \ **Category:** Factual Questions\ **Created:** [January 30, 2003, 3:17pm UTC](https://boards.straightdope.com/t/nuclear-power-for-dummies-can-someone-explain/151619 "2003-01-30T15:17:39Z")\ **Posts on this page:** 19\ **Page:** 2
**Author:** ![minor7flat5](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/minor7flat5/32/258_2.png) [@minor7flat5](https://boards.straightdope.com/u/minor7flat5)\ **Post date:** [February 1, 2003, 1:13am UTC](https://boards.straightdope.com/t/nuclear-power-for-dummies-can-someone-explain/151619/21 "2003-02-01T01:13:32Z")
> [@](#): > > \*Originally posted by Tranquilis \* > \*\ ***minor7flat5** , when’d you go to NNPS? 😉 \*\* '86 🆒 And you? ---
**Author:** ![Tranquilis](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tranquilis/32/3639_2.png) [@Tranquilis](https://boards.straightdope.com/u/Tranquilis)\ **Post date:** [February 1, 2003, 2:25am UTC](https://boards.straightdope.com/t/nuclear-power-for-dummies-can-someone-explain/151619/22 "2003-02-01T02:25:23Z")
Class 8501. 🆒 Protype at S1C 🆒 😛 🆒 ---
**Author:** ![minor7flat5](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/minor7flat5/32/258_2.png) [@minor7flat5](https://boards.straightdope.com/u/minor7flat5)\ **Post date:** [February 1, 2003, 3:20am UTC](https://boards.straightdope.com/t/nuclear-power-for-dummies-can-someone-explain/151619/23 "2003-02-01T03:20:29Z")
> [@](#): > > \*Originally posted by Tranquilis \* > \*\*Class 8501. 🆒 > > Protype at S1C 🆒 😛 🆒 \*\* 8604, D1G I am curious how many other readers are familiar with what we are talking about. ---
**Author:** ![Triskadecamus](https://avatars.discourse-cdn.com/v4/letter/t/b19c9b/32.png) [@Triskadecamus](https://boards.straightdope.com/u/Triskadecamus)\ **Post date:** [February 1, 2003, 3:39am UTC](https://boards.straightdope.com/t/nuclear-power-for-dummies-can-someone-explain/151619/24 "2003-02-01T03:39:14Z")
Navy Nuc Power School? Tris ---
**Author:** ![bbeaty](https://avatars.discourse-cdn.com/v4/letter/b/c0e974/32.png) [@bbeaty](https://boards.straightdope.com/u/bbeaty)\ **Post date:** [February 1, 2003, 4:20am UTC](https://boards.straightdope.com/t/nuclear-power-for-dummies-can-someone-explain/151619/25 "2003-02-01T04:20:05Z")
Hey, take a look: Natural U-235 reactor in ancient streambed [http://www.alamut.com/proj/98/nuclearGarden/bookTexts/Lovelock\_Oklo.html](http://www.alamut.com/proj/98/nuclearGarden/bookTexts/Lovelock_Oklo.html) Comparison of Oklo natural reactor to modern versions [http://www.physics.isu.edu/radinf/oklo.htm](http://www.physics.isu.edu/radinf/oklo.htm) Oklo fossil reactor FAQ [http://www.curtin.edu.au/curtin/centre/waisrc/OKLO/index.shtml](http://www.curtin.edu.au/curtin/centre/waisrc/OKLO/index.shtml) ---
**Author:** ![Tranquilis](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tranquilis/32/3639_2.png) [@Tranquilis](https://boards.straightdope.com/u/Tranquilis)\ **Post date:** [February 1, 2003, 7:25pm UTC](https://boards.straightdope.com/t/nuclear-power-for-dummies-can-someone-explain/151619/26 "2003-02-01T19:25:13Z")
> [@](#): > > \*Originally posted by minor7flat5 \* > \*\*8604, D1G > > I am curious how many other readers are familiar with what we are talking about. \*\* D1G Ball! 😃 Naval Nuclear _Propulsion_ School. Orlando, Florida (then). Prototype Reactors are for hands-on training, to turn the theory into _knowledge_ (and weed out the people who were book-smart, practice-dumb). S1C == **S** ubmarine Reactor, **1** st **C** ombustion Engineering design. D1G == **D** estroyer (Cruiser) Reactor, **1** st **G** eneral Electric design ---
**Author:** ![wnorthr](https://avatars.discourse-cdn.com/v4/letter/w/ecccb3/32.png) [@wnorthr](https://boards.straightdope.com/u/wnorthr)\ **Post date:** [February 4, 2003, 5:14pm UTC](https://boards.straightdope.com/t/nuclear-power-for-dummies-can-someone-explain/151619/27 "2003-02-04T17:14:22Z")
Is that windsor plant still there? I went in 75. ---
**Author:** ![cybersnark](https://avatars.discourse-cdn.com/v4/letter/c/b9e5f3/32.png) [@cybersnark](https://boards.straightdope.com/u/cybersnark)\ **Post date:** [February 4, 2003, 5:19pm UTC](https://boards.straightdope.com/t/nuclear-power-for-dummies-can-someone-explain/151619/28 "2003-02-04T17:19:02Z")
Here’s an online nuclear reactor simulator; can YOU prevent the meltdown? [http://www.ida.liu.se/~her/npp/demo.html](http://www.ida.liu.se/~her/npp/demo.html) ---
**Author:** ![yoyodyne](https://avatars.discourse-cdn.com/v4/letter/y/a9a28c/32.png) [@yoyodyne](https://boards.straightdope.com/u/yoyodyne)\ **Post date:** [February 5, 2003, 4:28am UTC](https://boards.straightdope.com/t/nuclear-power-for-dummies-can-someone-explain/151619/29 "2003-02-05T04:28:53Z")
8002, S1C 😃 ---
**Author:** ![Cortana](https://avatars.discourse-cdn.com/v4/letter/c/eb8c5e/32.png) [@Cortana](https://boards.straightdope.com/u/Cortana)\ **Post date:** [February 5, 2003, 4:56am UTC](https://boards.straightdope.com/t/nuclear-power-for-dummies-can-someone-explain/151619/30 "2003-02-05T04:56:07Z")
8807 S5G (at least… I THINK it was 8807… been so long) and an ELT at that… ---
**Author:** ![minor7flat5](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/minor7flat5/32/258_2.png) [@minor7flat5](https://boards.straightdope.com/u/minor7flat5)\ **Post date:** [February 5, 2003, 2:33pm UTC](https://boards.straightdope.com/t/nuclear-power-for-dummies-can-someone-explain/151619/31 "2003-02-05T14:33:42Z")
> [@](#): > > \*Originally posted by Cortana \* > \*\*8807 S5G (at least… I THINK it was 8807… been so long) > and an ELT at that… \*\* ELT as well 🆒 ---
**Author:** ![critter42](https://avatars.discourse-cdn.com/v4/letter/c/7ba0ec/32.png) [@critter42](https://boards.straightdope.com/u/critter42)\ **Post date:** [February 10, 2003, 4:16pm UTC](https://boards.straightdope.com/t/nuclear-power-for-dummies-can-someone-explain/151619/32 "2003-02-10T16:16:24Z")
9202, S1C I was in the next-to-last class to go through Windsor (or 2nd-to-last class - can’t remember for sure, but I know it was shut down in '93). I heard from one of the instructors that came to my ship after shutdown that when they did radiographic testing on the pipes, about the only thing holding Main Steam 1 together was the lagging 🙂 critter42 ---
**Author:** ![critter42](https://avatars.discourse-cdn.com/v4/letter/c/7ba0ec/32.png) [@critter42](https://boards.straightdope.com/u/critter42)\ **Post date:** [February 10, 2003, 4:22pm UTC](https://boards.straightdope.com/t/nuclear-power-for-dummies-can-someone-explain/151619/33 "2003-02-10T16:22:21Z")
> [@](#): > > \*Originally posted by critter42 \* > \*\*9202, S1C > > I was in the next-to-last class to go through Windsor (or 2nd-to-last class - can’t remember for sure, but I know it was shut down in '93). I heard from one of the instructors that came to my ship after shutdown that when they did radiographic testing on the pipes, about the only thing holding Main Steam 1 together was the lagging 🙂 > > critter42 \*\* Oh, forgot to add - wire-biter here 🙂 critter42 ---
**Author:** ![robby](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/robby/32/11048_2.png) [@robby](https://boards.straightdope.com/u/robby)\ **Post date:** [March 29, 2004, 12:57am UTC](https://boards.straightdope.com/t/nuclear-power-for-dummies-can-someone-explain/151619/34 "2004-03-29T00:57:38Z")
Apologies for resurrecting an old thread, but I just wanted to say that I had no idea there were so many ex-Navy nukes around here. –robby (9107, D1G) ---
**Author:** ![ralph124c](https://avatars.discourse-cdn.com/v4/letter/r/8797f3/32.png) [@ralph124c](https://boards.straightdope.com/u/ralph124c)\ **Post date:** [March 29, 2004, 6:10pm UTC](https://boards.straightdope.com/t/nuclear-power-for-dummies-can-someone-explain/151619/35 "2004-03-29T18:10:36Z")
The Canadian-designed reactor (CANDU) is able to run on unenriched uranium. Is this a big advantage? If these are such a good idea, why isn’t this design more common? Also, the gas-cooled reactors (they use helium or carbon dioxide as the coolant)-are these better than PW reactors? Finally-can a reactor be built that is totally foolproof? I mean-it would shut itself down automatically, without human intervention, in the event of a coolant leak, etc.? ---
**Author:** ![minor7flat5](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/minor7flat5/32/258_2.png) [@minor7flat5](https://boards.straightdope.com/u/minor7flat5)\ **Post date:** [March 29, 2004, 8:38pm UTC](https://boards.straightdope.com/t/nuclear-power-for-dummies-can-someone-explain/151619/36 "2004-03-29T20:38:58Z")
> [@ralph124c](#): > > Finally-can a reactor be built that is totally foolproof? I mean-it would shut itself down automatically, without human intervention, in the event of a coolant leak, etc.? How odd! I get to talk about decay heat in two different threads on the same day… Of course, there can never be a foolproof anything. That said, in most cases, reactors will shut themselves down when anything untoward happens (e.g. loss of coolent flow). The main problem, as I see it, is that even though the rods are at the bottom of the core, you aren’t out of the woods yet. Most of the random fission products created by fission are unstable and begin to decay as soon as they are formed. This decay process generates copious amounts of heat that must be removed from the core, for obvious reasons. The decay heat is generally a substantial fraction of the power level prior to shutting down. Consequently, whenever you shut down a reactor, normally or unexpectedly, you must still provide coolant flow to remove this decay heat. There are, of course, systems and backups of systems for providing this cooling in emergency situations, but the fact remains: some means of cooling must be present for a certain amount of time after shutdown. If all backup systems are hosed, the reactor will get really hot. ---
**Author:** ![sailor](https://avatars.discourse-cdn.com/v4/letter/s/a587f6/32.png) [@sailor](https://boards.straightdope.com/u/sailor)\ **Post date:** [March 29, 2004, 9:21pm UTC](https://boards.straightdope.com/t/nuclear-power-for-dummies-can-someone-explain/151619/37 "2004-03-29T21:21:11Z")
\>\> It is the job of the moderator to slow down neutrons That might explain why the moderators are required to wear those tinfoil hats 🙂 ---
**Author:** ![Cerowyn](https://avatars.discourse-cdn.com/v4/letter/c/82dd89/32.png) [@Cerowyn](https://boards.straightdope.com/u/Cerowyn)\ **Post date:** [March 29, 2004, 9:47pm UTC](https://boards.straightdope.com/t/nuclear-power-for-dummies-can-someone-explain/151619/38 "2004-03-29T21:47:15Z")
> [@ralph124c](#): > > The Canadian-designed reactor (CANDU) is able to run on unenriched uranium. Is this a big advantage? If these are such a good idea, why isn’t this design more common? CANDU reactors do in fact run on un-enriched uranium, but require heavy water (D[sub]2[/sub]O, with the deuterium isotype of hydrogen). IIRC, it’s a toss-up as to which is more expensive to produce, enriched uranium or heavy water, although I have to go with D[sub]2[/sub]O as the less dangerous of the two. Atomic Energy of Canada, Limited (AECL) lists [ten operational](http://www.aecl.ca/index.asp?menuid=21&miid=211&layid=3&csid=70) CANDU 6 units (plus one under construction). In all, they list [eleven locations around the world](http://www.aecl.ca/index.asp?menuid=21&miid=197&layid=3&csid=55) with CANDU reactors. ---
**Author:** ![Polycarp](https://avatars.discourse-cdn.com/v4/letter/p/82dd89/32.png) [@Polycarp](https://boards.straightdope.com/u/Polycarp)\ **Post date:** [March 29, 2004, 9:53pm UTC](https://boards.straightdope.com/t/nuclear-power-for-dummies-can-someone-explain/151619/39 "2004-03-29T21:53:46Z")
> [@sailor](#): > > \>\> It is the job of the moderator to slow down neutrons > > That might explain why the moderators are required to wear those tinfoil hats 🙂 LOL! That does explain a lot! 🙂 Actually, I’m posting to add in a small detail that seems to have escaped being mentioned in the above discussion: To achieve chain-reaction fission, whether in a reactor or a bomb, you require to have a concentration of a _fissionable isotope_. (While any isotope other than protium (H-1) can be fissioned, “fissionable isotope” here is a term of art, describing an isotope that naturally undergoes fission at an appreciable rate in the presence of neutrons.) Only one isotope exists in nature in any reasonable quantity which meets this description: Uranium-235. And in nature, it’s diluted in U-238 to approximately a 1:114 ratio. However, at least two other isotopes can be easily created from relatively common nuclides of elements: U-233, from Th-232, and Pu-239, from U-238 – the latter of which you have on hand in quantity from concentrating the U-235 to a pile-worthy degree. (I think U-234 is also fissionable, but it’s an order of magnitude rarer than U-235, which is itself less than 1% of natural uranium.) There are also numerous fissionable transuranic nuclides, but the only one I know of with any practical use is Americium, I believe isotope 241 – which could be used to make very small nuclear weapons and “portable” piles. [Previous page](https://boards.straightdope.com/t/nuclear-power-for-dummies-can-someone-explain/151619.md?page=1)