NASA's Basement Nuclear Reactor
cylonlover writes "If Joseph Zawodny, a senior scientist at NASA's Langley Research Center, is correct, the future of energy may lie in a nuclear reactor small enough and safe enough to be installed where the home water heater once sat. Using weak nuclear forces that turn nickel and hydrogen into a new source of atomic energy, the process offers a light, portable means of producing tremendous amounts of energy for the amount of fuel used. It could conceivably power homes, revolutionize transportation and even clean the environment."
If you RTFA you find it is not expected to produce objectionable byproducts like regular reactors. It says that unlike fission and fusion reactions that depend on the strong nuclear force for their energy this is drawing energy from the weak nuclear force. Like fusion though it appears to be mostly in the experimental stage and is years away from practical application. One difficulty they have is they need to generate vibrations in the 5-30 THz range which the researcher calls "the valley of inaccessibility".
There was a colloquium at CERN last year, see http://indico.cern.ch/conferenceDisplay.py?confId=177379
you will find the presentation about the Widom-Larsen-Srivastava that TFA talks about.
you will also find the slides about the Mitsubishi Heavy Industries transmutation experiment (and the Toyota replication of it) http://indico.cern.ch/getFile.py/access?resId=5&materialId=slides&confId=177379
As mentioned above it was also presented at the American Nuclear Society's winter meeting in Nov 2012:
"Replication experiments have been performed in some universities or institutes mainly in Japan. T.Higashiyama et al. of Osaka University observed transmutation of Cs into Pr in 2003[7]. H.Yamada et al. performed similar experiments using Cs and detected increase of mass number 137 by TOF-SIMS. They used a couple of nano-structured Pd multilayer thin film and observed the increase of mass number 141 (corresponding to Pr) only when 133Cs was given on the Pd sample [8]. N. Takhashi et al., the researchers of Toyota Central R&D Labs, presented that they detected Pr from the permeated Pd sample using SOR x-ray at Spring-8 and the detected Pr was confirmed by ICP-MS and TOF-SIMS [8]." http://newenergytimes.com/v2/conferences/2012/ANS2012W/2012Iwamura-ANS-LENR-Paper.pdf
All kinds of information nuclear reactions and decay is available in "Nuclides and Isotopes", a chart of the nuclides published by KAPL (Knowles Atomic Power Laboratory). I recommend the "chart" in book form as it comes with a bunch of nuclear physics discussion. Based on the description in the article Ni+n=Cu+e. There is only one stable isotope of Ni that has a chance of going through this process and resulting in a stable isotope of copper and that is Ni62. Ni62 is only 3.63% of naturally occurring nickle. The most abundant isotope is Ni58 (68.07%) and it will go to Ni59 with addition of a neutron and will beta decay to Co59. Ni59 has a 7600 year half life so you could continue to change it to Ni60 then Ni61 then Ni62, but all of this wouldn't happen instantaneously as stated in the article (I guess you could start an enrichment plant so you are only using Ni62, but that cost a lot of money and energy and would have to be factored into the energy balance of the final "reactor"). These types of reactions don't take place in nature because the stable isotopes are already at the bottom of the "valley of stability" (have a minimum mass or maximum binding energy, see pages 27-28 of the 16th edition of the "Nuclides and Isotopes"). I guess it is possible that the 30THz vibrations change the local laws of physics, but I will remain skeptical until there is more than speculation. The article states, "LENR is a very long way from the day when you can go out and buy a home nuclear reactor. In fact, it still has to be proven that the phenomenon even exists, but hundreds of experiments worldwide indicate that heat and transmutations with minimal radiation and low energy input do take place with yields of 10 to 100 watts." TFA states that they are not even sure if the phenomenon exists and it doesn't provide the total energy input to the system so you can't tell if 10-100W is noise or error in the measuring equipment (this is one of the things that was going on in the cold fusion of years past).
GENERATION 27: The first time you see this, copy it into your sig on any forum and add 1 to the generation.
For the purpose of this post, I'll accept that they can convert protons to neutrons as described, although I'm very dubious about this.
Here is a table of nickel isotopes.
Here is the first source I found for neutron cross sections of nickel isotopes (pdf). (See figure 12, look at the left hand side of each 'destruction channels for ??Ni' plot for what low energy (thermal) neutrons will do.)
Cross sections are in barns, and are approximate as I'm eyeballing them off a logarithmic scale.
58Ni [stable, 68% abundant] (0.006 barn) -> 59Ni [-> 59Co, 76000 yr half life]
59Ni [unstable but long lived] (0.02b) -> 59Co [stable] or (0.005b) ->56 Fe [stable] or (0.004b) -> 60Ni [stable]
60Ni [stable, 26%] (0.006b) -> 61Ni [stable]
61Ni [stable, 1%] (0.002b) -> 62Ni [stable]
62Ni [stable, 4%] (0.006b) -> 63Ni [->63Cu, 100yr]
63Ni [unstable] (0.001b)-> 64Ni [stable]
64Ni [stable, 1%] (0.004b) -> 65Ni [->65Cu, 2.5 hr]
None of the cross sections are hugely larger than the others, so all these reactions will occur with reasonable frequency. So irradiating nickel with thermal neutrons, you are going to produce radioactive 59Co (76000yr), 63Ni (100yr) and 65Ni (2.5hr). The 65Ni isn't a problem - turn off the reactor, wait a couple of days, and it will all be gone. The 59Co is only a bit of a problem - with such a long half life, it isn't very radioactive. The 63Ni however is nasty. Like 137Cs (30yr) from the Fukashima reactors, the half life is short enough to be quite radioactive but long enough that you can't just wait it out. Finally, the nickel won't be 100% pure, so you have to worry about what neutron irradiation will do to the impurities.
The 65Ni means when you turn off your reactor, it will continue to produce residual heat for hours.
The article gives the impression that weak nuclear reactions aren't dangerous, but this is not so. If it were, nuclear reactor waste wouldn't be dangerous.
This reactor will be producing ionizing radiation when running (mostly gamma rays, some beta rays mostly from 65Ni decay, and a tiny amount of alpha particles from 59Co(n,a)56Fe.) This will require some pretty heavy shielding to stop it. (A good sized water bath should work, every 7cm of water halves the radiation and you want hot water anyhow. But concrete is less prone to leak away.) You'd also need to worry about stray neutrons, although I expect that can be fixed with a thin layer of something that has very high thermal neutron cross section and no dangerous daughter products.
In short, I don't think I want this in my basement.
Quattuor res in hoc mundo sanctae sunt: libri, liberi, libertas et liberalitas.
LENR is a very long way from the day when you can go out and buy a home nuclear reactor. In fact, it still has to be proven that the phenomenon even exists
But what about all those reactors that blew up or melted (in TFA)? Or were they cheating and just bombarding the nickel with slow neutrons? One would think that if they produced an exothermic reaction even one time and weren't complete Pons and Fleishman nutcases they'd be able to pick up the beta (if not gamma) signature of the events. I'm also a bit curious as to just where the energy produced "comes out". They assert that no gamma rays happen. They get electron and neutrino out. Presumably we're talking about order of MeV/event, so the reaction produces order of MeV electrons (we hope, as energy going into neutrinos is gone forever) and a certain amount of lattice recoil in the now-copper nucleus. MeV electrons seem to have enough energy to produce an electron-positron cascade and convert at least some of the energy into X-rays (ionizing radiation). Probably relatively easily stopped (as is the beta itself) but the process would likely not be "radiation free". Finally, those same electrons seem as though they have the right general range of energy to be captured by the hydrogen nuclei (or would, if they didn't scatter on the way in and if there was any sort of cross-section) leaving open the possibility that the electrons themselves would create the requisite electron excitation and some sort of chain reaction might be possible.
Interesting idea, in other words, but TFA doesn't clarify the underlying physics to the point where it is really intelligible.
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Even when the experts all agree, they may well be mistaken. --- Bertrand Russell.