Radioactive waste processing method

Patent metadata

Field	Value
Publication number	US-10629316-B2
Application number	US-201615559736-A
Country	US
Kind code	B2
Filing date	Mar 22, 2016
Priority date	Mar 20, 2015
Publication date	Apr 21, 2020
Grant date	Apr 21, 2020

Abstract

Provided is a fission product processing method for selectively transmuting only a long-lived radionuclide from fission products. The method for processing radioactive waste includes the step of extracting, from the radioactive waste, the isotopes without isotope separation, the isotope elements including radionuclides of fission products and having a common atomic number, and the step of irradiating the isotopes with high-energy particles generated by an accelerator to produce nuclear transmutation of a long-lived radionuclide of the radionuclides into a short-lived radionuclide with a short half-life or a stable nuclide re-utilizable as a resource.

First claim

The invention claimed is:

1. A method for processing radioactive waste, comprising:
a step of extracting a group of isotopes having a same atomic number from the radioactive waste, followed by no separation process of isotopes from the extracted group, the extracted group including a radionuclide and stable nuclides; and
a step of generating a neutron (n) by an accelerator and irradiating the neutron (n) to the isotopes, so as to produce nuclear transmutation of a first nuclide as a long-lived radionuclide into a second nuclide as a stable nuclide, while suppressing nuclear transmutation of a third nuclide into the first nuclide by setting a value of irradiation energy of the neutron (n) within such a range that a (n, 2n) reaction cross section of the first nuclide is equal to or larger than 10 times as large as a (n, 2n) reaction cross section of the third nuclide,
and
wherein the isotopes, the first nuclide, the second nuclide, and the third nuclide are defined as below:
selenium (Se) isotopes, Se-79, Se-78, and Se-80, respectively;
palladium (Pd) isotopes, Pd-107, Pd-106, and Pd-108, respectively;
zirconium (Zr) isotopes, Zr-93, Zr-92, and Zr-94, respectively;
krypton (Kr) isotopes, Kr-85, Kr-84, and Kr-86, respectively; or
samarium (Sm) isotopes, Sm-151, Sm-150, and Sm-152, respectively.

2. The radioactive waste processing method according to claim 1 , further comprising:
after the extracting step and before the irradiating step, a step of increasing or decreasing a ratio of isotopes having an odd number of neutrons with respect to isotopes having an even number of neutrons in the extracted group of isotopes, by inducing an isotopic shift phenomenon in the extracted group of isotopes.

Assignees

• Riken

Inventors

• Fujita Reiko
• Otsu Hideaki
• Matsuzaki Teiichiro
• Sakurai Hiroyoshi
• Shimoura Susumu
• Mizuguchi Koji
• Oigawa Hiroyuki
• Ozawa Masaki
• Nitta Koji

Classifications

• G21F9/00 Primary

  Treating radioactively contaminated material; Decontamination arrangements therefor · CPC title

• G21G1/08 Primary

  accompanied by nuclear fission · CPC title

• H05H6/00

  Targets for producing nuclear reactions (supports for targets or objects to be irradiated G21K5/08 {; preparation of tritium C01B4/00; targets, e.g. pellets for fusion reactions by laser or charged particles beam injection H05H1/22}) · CPC title

• G21K5/08

  Holders for targets or for other objects to be irradiated · CPC title

• G21G1/10

  by bombardment with electrically charged particles (irradiation devices G21K5/00) · CPC title