The France patent FR2553560 was lapsed in 1998, as notification of lapse. The patent is valuable. I think it is used in MOX plant. I would like to know the reason of lapse of the valuable patent. How can I do that?

  • It should be noted that the questioner is very likely the same Akihiko Inoue listed as an inventor on the cited patent. It seems Mr. Inoue has an extensive list of patents to his name.
    – Eric S
    Commented Apr 28, 2018 at 13:37
  • I have to know the detail of the lapse of France version FR2553560 rather than the Japanese version because the Japanese version was maintained to the lifetime. Commented Apr 30, 2018 at 16:15
  • As far as I can see, your only option is to contact the assignee.
    – Eric S
    Commented May 1, 2018 at 1:36
  • I have already contacted with the assignee. They, however do not respond to my question. Commented May 1, 2018 at 5:17
  • I suspect that the registration of Japanese version of the patent was transferred to AREVA Japan from assignee JAERI and maintained during the lifetime of the patent. French version of the patent was lapsed due to the nonpayment of patent fee on the basis of the contract beteween JAERI and AREVA Commented May 4, 2018 at 0:27

1 Answer 1


Short of asking the assignee of the patent: Japan Atomic Energy Research Institute, there is no way to know why they allowed the patent to lapse. Generally the reason for allowing a patent to lapse is that the patent owner no longer feels the patent fees are justified by the income or protection derived by the patent. Perhaps no one in France was "dissolving plutonium dioxide or a mixed oxide of uranium and plutonium" using the described method after 1998? It should be noted that the patent would have expired anyway on October 12th, 2003.

  • Thanks for your answer. You are right on the basis of the facts about the lapse of this patent. However, I believe that the patent was valuable until lapsed. There is no reason for nonpayment of patent fee. The assignee, JAERI reject display of the reason of the lapse for the patent. The MOX fuel prepared by this method, dissolving PuO2 in nitric acid, exists now in Takahama nuclear reactor of Japan. Commented Apr 28, 2018 at 21:10
  • @AkihikoInoue As far as I could tell, the Japanese equivalent patent didn’t lapse.
    – Eric S
    Commented Apr 28, 2018 at 22:05
  • The Japanse equivalent patent was lapsed in 1997 April before the lapse of France patent FR2553560 Commented Apr 28, 2018 at 22:42
  • MOX fuel is prepared by French company AREVA Commented Apr 28, 2018 at 23:16
  • @AkihikoInoue I have no knowledge of this field. It might be that AREVA already had a contract with JAERI so that maintaining the French patent was not necessary.
    – Eric S
    Commented Apr 29, 2018 at 15:50

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