Sintered body for radiation shielding material, radiation shielding material, and method for producing the same

Patent metadata

Field	Value
Publication number	US-12362075-B2
Application number	US-202117407853-A
Country	US
Kind code	B2
Filing date	Aug 20, 2021
Priority date	Apr 16, 2021
Publication date	Jul 15, 2025
Grant date	Jul 15, 2025

Abstract

As a sintered body for a radiation shielding material, which can effectively shield mainly low-energy-level neutrons, that is, thermal neutrons and lower, slow neutrons, and has excellent physical properties such as bending strength and Vickers hardness, leading to high machining strength, a sintered body for a radiation shielding material comprising LiF ranging between 99 wt. % to 5 wt. %, and one or more fluorides selected from among MgF 2 , CaF 2 , AlF 3 , KF, NaF, and/or YF 3 ranging between 1 wt. % to 95 wt. %, having physical properties of a relative density of 92% or more, a bending strength of 50 MPa or more, and a Vickers hardness of 100 or more, is provided.

First claim

The invention claimed is:

1. A sintered body for a radiation shielding material, comprising:
over 95 wt. % to 99 wt. % of LiF, and
1 wt. % to 5 wt. % of one or more fluorides selected from the group consisting of MgF 2 , CaF 2 , AlF 3 , KF, NaF, and YF 3 ,
wherein the sintered body has a relative density of over 92%,
wherein the sintered body has a bending strength of 50 MPa or more, and
wherein the sintered body has a Vickers hardness of 100 or more.

2. The sintered body for a radiation shielding material according to claim 1 ,
wherein 0.1-5 wt. % of a boron compound selected from the group consisting of B 2 O 3 , B(OH) 3 , LiB 3 O 5 , and Li 2 B 4 O 7 is further added as a boron isotope 10 B, and/or
wherein 0.1-2 wt. % of a gadolinium compound selected from the group consisting of Gd 2 O 3 , Gd(OH) 3 , and GdF 3 is added as a gadolinium isotope 157 Gd.

3. The sintered body for a radiation shielding material according to claim 1 , wherein the radiation is a neutron beam.

4. The sintered body for a radiation shielding material according to claim 2 , wherein the radiation is a neutron beam.

5. A radiation shielding material, which is formed by machining the sintered body for a radiation shielding material according to claim 1 .

6. A radiation shielding material, which is formed by machining the sintered body for a radiation shielding material according to claim 2 .

7. The radiation shielding material according to claim 5 , wherein the shielding material formed by machining the sintered body has a thickness of 100 mm or less in a radiation irradiation field, has thermal neutron shielding performance expressed as a value obtained by dividing a thermal neutron flux outgoing from the shielding material (N1) by a thermal neutron flux incident on the shielding material (N0) that is a thermal neutron attenuation factor (N1/N0) of 1/100 or less.

8. The radiation shielding material according to claim 6 , wherein the shielding material formed by machining the sintered body has a thickness of 100 mm or less in a radiation irradiation field, has thermal neutron shielding performance expressed as a value obtained by dividing a thermal neutron flux outgoing from the shielding material (N1) by a thermal neutron flux incident on the shielding material (N1) that is a thermal neutron attenuation factor (N1/N0) of 1/100 or less.

9. The sintered body for a radiation shielding material according to claim 1 , wherein the one or more fluorides include both MgF 2 and CaF 2 .

Assignees

• Univ Tsukuba
• Aist
• Daico Mfg Co Ltd

Inventors

• Kumada Hiroaki
• Kitamura Naoyuki
• Nakamura Tetsuyuki
• Ikeda Takeshi

Classifications

• C04B2235/661

  Multi-step sintering · CPC title

• C04B2235/656

  characterised by specific heating conditions during heat treatment · CPC title

• C04B2235/612

  Machining · CPC title

• C04B2235/604

  Pressing at temperatures other than sintering temperatures · CPC title

• C04B2235/5436

  micrometer sized, i.e. from 1 to 100 micron · CPC title