Fast reactor with primary and backup control rods

Patent metadata

Field	Value
Publication number	US-11854709-B2
Application number	US-202117185009-A
Country	US
Kind code	B2
Filing date	Feb 25, 2021
Priority date	Feb 28, 2020
Publication date	Dec 26, 2023
Grant date	Dec 26, 2023

Abstract

A fast reactor core includes a sodium plenum installed above the fuel. The sodium plenum is capable of reducing a void reactivity. During operation, a tip of a primary control rod is inserted in a core fuel region, and a tip of a backup control rod is arranged near an upper end of the sodium plenum.

First claim

What is claimed is:

1. A core of a fast reactor including a sodium plenum installed above a core fuel, comprising:
a core fuel region in which the core fuel is disposed;
a sodium plenum region in which the sodium plenum is disposed;
a primary control rod; and
a backup control rod;
wherein only a lower tip of the primary control rod is inserted into an upper end of the core fuel region in a normal operation state of the fast reactor, and
in the sodium plenum region, in which the sodium plenum is disposed above an upper end of the core fuel region, only a central portion of the primary control rod above the lower tip of the primary control rod and only a lower tip of the backup control rod are arranged in the sodium plenum region in the normal operation state of the fast reactor,
wherein the lower tip of the backup control rod is arranged at a position substantially same as an upper end of the sodium plenum for operation.

2. The core of a fast reactor according to claim 1 , wherein
in a radial direction of the core, the core fuel region has an inner core fuel region arranged on a center side and an outer core fuel region arranged around the inner core fuel region, and
in an axial direction of the core, a length of a fuel rod of an inner core fuel assembly loaded in the inner core fuel region is shorter than that of a fuel rod of an outer core fuel assembly loaded in the outer core fuel region, and a length of the sodium plenum on the inner core fuel assembly is longer than that of the sodium plenum on the outer core fuel assembly.

3. The core of a fast reactor according to claim 2 , wherein
a radial blanket region radially outward of the outer core fuel region, and a shield region radially outward of the radial blanket region are provided.

4. The core of a fast reactor according to claim 3 , wherein
a gas expansion module assembly is provided between the outer core fuel region and the radial blanket region.

Assignees

• Hitachi Ge Nuclear Energy Ltd

Inventors

• Fujimura Koji
• Fujimata Kazuhiro
• Fuchita Sho
• Miwa Junichi

Classifications

• G21C1/02 Primary

  Fast fission reactors, i.e. reactors not using a moderator {; Metal cooled reactors; Fast breeders} · CPC title

• G21C1/03

  cooled by a coolant not essentially pressurised, e.g. pool-type reactors · CPC title

• G21C3/28

  with fissile or breeder material in solid form within a non-active casing · CPC title

• G21C1/024

  where the core is divided in zones with fuel and zones with breeding material · CPC title

• G21C7/08

  by displacement of solid control elements, e.g. control rods · CPC title