Nuclear power plant that can automatically close a steam safety relief valve upon determination of exhaust pipe leakage

Patent metadata

Field	Value
Publication number	US-10438707-B2
Application number	US-201715420407-A
Country	US
Kind code	B2
Filing date	Jan 31, 2017
Priority date	Feb 5, 2016
Publication date	Oct 8, 2019
Grant date	Oct 8, 2019

Abstract

An atomic power plant is provided including a primary containment vessel (PCV) 1 , a reactor pressure vessel (RPV) 3 , a main steam line 4 , two steam safety relief valves (SRVs) 6 , a pressure suppression pool (S/P) 8 , an SRV exhaust pipe 9 which is connected to a quencher 10 , a temperature measuring instrument 12 which measures a temperature inside the quencher 10 , an SRV controller 13 which controls opening and closing of the SRVs 6 . After a lapse of predetermined time from when the SRV 6 is opened, in a case where it is determined that a temperature detected by the temperature measuring instrument 12 is equal to or smaller than a predetermined threshold value, the SRV controller 13 causes the SRV 6 to which the temperature measuring instrument 12 detecting the temperature leads, to be closed and to be prohibited from being opened.

First claim

The invention claimed is:

1. An atomic power plant comprising:
a primary containment vessel;
a reactor pressure vessel which is disposed inside the primary containment vessel and internally accommodates a core;
a main steam line which is connected to the reactor pressure vessel and leads to a turbine;
at least two or more steam safety relief valves which are independently connected to the main steam line;
a pressure suppression pool which is provided inside the primary containment vessel;
an exhaust pipe in which one end is connected to each of the steam safety relief valves and the other end is connected to a quencher below a water level of the pressure suppression pool;
a condition detector,
wherein the condition detector is in fluid communication with the at least two or more steam safety relief valves,
wherein the condition detector is associated with a steam safety relief valve of the at least two or more steam safety valves,
wherein the condition detector is configured to detect, from inside the quencher or from inside the exhaust pipe at a location below the water level of the pressure suppression pool, a condition of steam leakage from the exhaust pipe while the steam safety relief valve is open; and

a control unit,
wherein the control unit controls opening and closing of the at least two or more steam safety relief valves,
wherein the control unit is configured to determine while the steam safety relief valve is open, whether a condition of steam leakage is detected by the condition detector after lapse of a predetermined time period from when the steam safety relief valve was opened,
wherein the control unit causes, responsive to a positive determination of a condition of steam leakage, the steam safety relief valve to be closed and to be prohibited from being opened.

2. The atomic power plant according to claim 1 ,
wherein the condition detector includes a temperature measuring instrument,
wherein the temperature measuring instrument measures a temperature inside the quencher,

wherein the control unit is configured to determine, while the steam safety relief valve is open, whether a temperature detected by the temperature measuring instrument after lapse of the predetermined time period is equal to or smaller than a predetermined threshold value,
wherein, while the steam safety relief valve is open, a temperature inside the quencher being equal to or smaller than the predetermined threshold value is associated with a condition of steam leakage,
wherein the control unit causes, responsive to a positive determination of a detected temperature being equal to or smaller than the predetermined threshold value, the steam safety relief valve to be closed and to be prohibited from being opened.

Assignees

• Hitachi—Ge Nuclear Energy Ltd
• Hitachi Ge Nuclear Energy Ltd

Inventors

• Kito Kazuaki
• Matsuzaki Takahisa
• Ikegawa Tomohiko

Classifications

• G21C15/18

  Emergency cooling arrangements; Removing shut-down heat · CPC title

• G21C9/004 Primary

  Pressure suppression · CPC title

• G21C1/084

  Boiling water reactors · CPC title

• G21C9/012 Primary

  by thermal accumulation or by steam condensation, e.g. ice condensers · CPC title

• Y02E30/40

  Cross-Sectional Technologies · mapped topic