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Lovelock and Pu-240[edit]

A question has arisen on the James Lovelock article, about the sentence This is because the Plutonium-239 from a nuclear reactor power plant is contaminated with a significant amount of Pu-240, so it is not weapons-grade. It is easier to enrich Uranium than than to separate the Pu-240 from the Pu-239. that was removed from there as unsupported. This article appears to discuss the same matter, though from my reading of it, it does not state that reactor-Pu can't be used; and it isn't sourced either William M. Connolley (talk) 09:44, 23 November 2007 (UTC)

Which part of the quote is being questioned? The statements you quote here are standard and uncontroversial, and the Lovelock article even does appear to have a reference for them, but the conclusion that reactor grade plutonium is of little use for bombs is debatable, although conventional wisdom and frequently stated. You might want to look at Reactor grade plutonium nuclear test, Nuclear weapons design and Weapons-grade among others. Also, fusion boosting which is used anyway in all modern nuclear weapons mitigates the predetonation problem from Pu-240. --JWB (talk) 22:19, 23 November 2007 (UTC)
Thanks for the comment. The article *now* has "although reactor-grade plutonium can successfully be used in weapons[10][11]." [1] in it, which rather alters the previous sense, and I think fits with what you are saying William M. Connolley (talk) 22:51, 23 November 2007 (UTC)

Can CANDU do or can't do?[edit]

It is stated that a pressurized heavey water reactor can be used to manufacture 238 PU. A CANDU is a pressurized heavy water reactor but you say it would burn the 238 PU rather than produce it? So if it can't make PU why not? Could a country easily modify or adapt a CANDU reactor to create PU? If there is no problem with CANDU technology why did the Canadians quickly say they wouldn't give the Iranians a CANDU reactor. If it can't do, then we should be happy to give it to them. (talk) 04:52, 14 August 2009 (UTC)

CANDU reactors are equipped with automated online refuelling equipment that cannot be operated in a manual mode without obvious modification. AECL says that the equipment cannot be modified for a higher duty cycle, which would be necessary for efficient 239Pu extraction, without impaired reliability. The result of the axial and radial shuffling of fuel through the core is that the bundles all end up with relatively high burnup. AECL says that it would require 50x the fuel bundles (100), versus a PWR (2), to gather a critical mass of Pu. Depending on the weapon design, this may over or under-represent the material target for a weapons program racing to test. The takeaway may be that CANDU cannot be used to covertly supply a weapons program under safeguards. VmZH88AZQnCjhT40 (talk) 01:52, 1 May 2014 (UTC)

Half-life of plotonium-239[edit]

The plutonium article says: The most important isotope of plutonium is plutonium-239, with a half-life of 24,100 years. This article says 24200, so which one is correct? (talk) 12:51, 8 May 2011 (UTC)

Numerical error in "Sum" and "Energy converted into heat"[edit]

Is it really possible for the reactor to extract more energy than the total energy released from the fission? (211.5 MeV vs 207.1 MeV) — Preceding unsigned comment added by (talk) 15:55, 8 July 2011 (UTC)

Internal energy of neutron's emited in fission makes that possible. — Preceding unsigned comment added by (talk) 17:48, 17 January 2018 (UTC)


Can someone check that the amount of energy released by one Pu-239 fissioning is really 211.5 MeV? If that is true AND the critical mass is 5-10 kg, the minimum yield you'd be able to get out of a Pu-239 nuke would be 100-200 kilotons, several orders of magnitude too high. Perhaps someone can explain this seeming contradiction? Quodfui (talk) 01:00, 20 November 2012 (UTC)

Never mind, not all of it fissions. Quodfui (talk) 01:08, 20 November 2012 (UTC)

Hazards, Proliferation[edit]

This statement:

"Its storage, as fuel or as nuclear waste, must be very secure."

is too vague. It would obviously refer only to weapons grade Plutonium. However, unless a IFR was being used to dispose of unwanted weapons grade Plutonium, weapons grade Plutonium would not be being used for fuel for a IFR. It is even more questionable for "nuclear waste" since Plutonium refined from nuclear waste is always reactor grade Plutonium with less than 60% Plutonium-239 and a large percentage of Plutonium-240.

Wikipedia should be careful not to perpetrate the myth that nuclear weapons can be produced from nuclear waste unless Wikipedia is taking an anti-nuclear power position (which is propaganda). There is no neutral position here, only the truth, which is that is is not possible. Weapons grade Plutonium is at least 90% 239 and contains less than 7% 240. Slightly lower grades can make an explosive, but reactor grade with less than 60% 239 simply cannot.

Tyrerj (talk) 15:21, 26 March 2015 (UTC)


Corrected blatantly incorrect claim that "less than 1mg of plutonium ingested would cause cancer". Inhaled plutonium is very dangerous but fortunately it's very unlikely to be gaseous. According to the (cited!) Bernard Cohen's book he has offered to eat as much plutonium on live tv as an anti-nuclear activist will eat caffeine. He considers 800mg to be pretty safe level or "similar risk as WWII soldier". — Preceding unsigned comment added by Barleyman74 (talkcontribs) 09:42, 18 May 2016 (UTC)

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