Device for passive protection of a nuclear reactor

• US 10,643,755 B2
• Filed: 04/05/2016
• Issued: 05/05/2020
• Est. Priority Date: 06/01/2015
• Status: Active Grant

• Current Assignee: State Atomic Energy Corporation Rosatom
• Original Assignee: State Atomic Energy Corporation Rosatom
• Inventors: Slesarev, Igor Sergeevich, Leonov, Viktor Nikolaevich, Kubintsev, Boris Borisovich, Rodina, Elena Aleksandrovna, Chernobrovkin, Yuriy Vasilevich, Shevchenko, Aleksey Borisovich
• Primary Examiner(s): Garner, Lily C
• Application Number:
  US15/578,950
• Publication Number:
  US 20180174693A1
• Time in Patent Office: 1,491 Days
• CPC Class Codes: G21C 15/18 Emergency cooling arrangements; Removing shut-down heat
• CPC Class Codes: G21C 3/326 comprising fuel elements of different composition; comprising, in addition to the fuel elements, other pin-, rod-, or tube-shaped elements, e.g. control rods, grid support rods, fertile rods, poison rods or dummy rods
• CPC Class Codes: G21C 7/22 by displacement of a fluid or fluent neutron-absorbing material , e.g. by adding neutron-absorbing material to the coolant
• CPC Class Codes: G21C 7/24 Selection of substances for use as neutron-absorbing material
• CPC Class Codes: G21C 9/024 Rupture diaphragms
• CPC Class Codes: G21C 9/033 by an absorbent fluid
• CPC Class Codes: Y02E 30/30 Nuclear fission reactors

Abstract

The invention relates to nuclear reactor protection systems and can be used when building nuclear reactors, in particular, the fast neutron reactors. The Technical result of the invention consists in the expansion of 5 functional capabilities of the negative reactivity passive insertion device by securing its reliable actuation in various emergency conditions. The device has two vessels located in a common enclosure one under another with a ring-shape hollow space between the vessels and the enclosure to let the heat carrier flow. Fuel elements are located in the ring-shape hollow space, as well as the tooling for the heat carrier flow formation to cool the fuel elements and heat the upper vessel. The upper vessel is located above the reactor core and is divided with an internal partition wall to the central cylindrical and ring-shape hollow spaces. The partition wall has low thermal conductivity in the transverse direction. In the central hollow space of the upper vessel the cadmium isotope is mainly located, while in its ring-shape space—mercury. Lower vessel is mainly located in the active core of the reactor and filled with inert gas. The vessels and are connected with a pipe with a partition, made in the form of buckling rapture disc.

Claims

1. A device for nuclear reactor passive protection comprises:

two vessels located in a common enclosure one under another,

an upper vessel is located above a reactor core and has an internal partition wall forming a central hollow space and an annular hollow space that are interconnected with each other in their upper parts, wherein the central hollow space is partially filled with a molten cadmium and the annular hollow space is partially filled with a molten mercury;

an upper annular hollow space is formed between the upper vessel and the enclosure;

a lower vessel is located in the reactor core and is filled with an inert gas;

a lower annular hollow space is formed between the lower vessel and the enclosure, the lower annular hollow space encloses fuel elements;

the vessels are interconnected by a partitioned pipe where the partition is made in the form of a buckling rapture disc,

wherein lower annular hollow space and the upper annular hollow space are interconnected with each other and configured to allow for a heat carrier flow to cool down the fuel elements and heat the upper vessel.

2. The device according to claim 1, characterized in that the molten mercury comprises mercury isotope ¹⁹⁹Hg, and the molten cadmium comprises cadmium isotopes ¹¹¹Cd and/or ¹¹³Cd.

3. The device according to claim 1 characterized in that the internal partition wall is made of two layers separated by a gas heat-insulating gap.

4. The device according to claim 1, characterized in that a lower pipe shell is located between the lower vessel and the fuel elements for shaping the heat carrier flow to cool the fuel elements, wherein the lower pipe shell has a transverse partition wall at the top, wherein the transverse partition wall intersects a central part of the lower annular hollow space.

5. The device according to claim 1, characterized in that an upper pipe shell is located between the upper vessel and the enclosure for shaping the heat carrier flow to heat the upper vessel, wherein the upper pipe shell has a transverse partition wall at the bottom, wherein the transverse partition wall intersects a peripheral part of the lower annular hollow space.

6. The device according to claim 4, characterized in that a hollow space is formed between the lower vessel and the lower pipe shell, and a hollow space is formed between the enclosure and the upper pipe shell, wherein the hollow spaces are interconnected with each other via at least one pipe channel.

7. The device according to claim 1, characterized in that the shape and the size of the enclosure in its cross-section match the shape and the size of the reactor fuel assembly.

8. The device according to claim 7, characterized in that the enclosure has a hexagonal cross-section.

9. The device according to claim 4, characterized in that the cross-sectional shape of the lower pipe shell matches the shape of the enclosure.

10. The device according to claim 5, characterized in that the cross-sectional shape of the upper pipe shell matches the shape of the upper vessel.

11. The device according to claim 1 characterized in that pipe elements containing a neutron moderator are located between the lower vessel and the lower pipe shell.

12. The device according to claim 11, wherein the neutron moderator is beryllium oxide.