Managing Electrical Power for a Nuclear Reactor System

• US 20140152098A1
• Filed: 03/12/2013
• Published: 06/05/2014
• Est. Priority Date: 12/04/2012
• Status: Active Grant

• Current Assignee: NuScale Power, LLC.
• Original Assignee: NuScale Power, LLC.
• Inventors: Hough, Ted
• Granted Patent: US 9,305,671 B2
• Time in Patent Office: Days
• US Class Current: 307/23
• CPC Class Codes: G21D 1/00 Details of nuclear power plant control G21D3/00
• CPC Class Codes: G21D 3/04 Safety arrangements emergency protection of reactor G21C9/00
• CPC Class Codes: H02J 2310/18 The network being internal to a power source or plant
• CPC Class Codes: H02J 3/0073 for providing alternative feeding paths between load and source when the main path fails, e.g. transformers, busbars
• CPC Class Codes: H02J 9/06 with automatic change-over , e.g. UPS systems
• CPC Class Codes: H02J 9/062 for AC powered loads
• CPC Class Codes: Y02E 30/00 Energy generation of nuclear origin
• CPC Class Codes: Y02E 30/30 Nuclear fission reactors
• CPC Class Codes: Y04S 10/52 Outage or fault management, e.g. fault detection or location

Abstract

An electrical power system for a nuclear power facility includes an active alternating current (AC) power bus configured to be electrically coupled to a plurality of engineered safety feature (ESF) loads of a plurality of nuclear power systems, each of the ESF loads configured to fail to a safe position upon loss of primary AC power; a critical battery system electrically coupled to the active AC bus, the critical battery system comprising a plurality of valve regulated lead acid (VRLA) batteries; and a primary AC power source electrically coupled to the active AC bus.

Claims

1. An electrical distribution system for a nuclear power plant, comprising:

at least one primary alternating current (AC) power source;

a first plurality of AC loads of a plurality of nuclear reactor systems of the nuclear power plant, each of the first plurality of AC loads comprising a critical electrical load of the plurality of nuclear reactor systems that is configured to fail to a safety position based on a loss of electrical power from the primary AC power source;

a first AC power bus that is electrically coupled to the at least one primary AC power source, the first plurality of AC loads, and a first critical battery system that comprises one or more non-qualified battery sources;

a second plurality of AC loads of the plurality of nuclear reactor systems, each of the second plurality of AC loads comprising a non-critical electrical load of the plurality of nuclear reactor systems; and

a second AC power bus that is electrically coupled to the at least one primary AC power source, the second plurality of AC loads, and a non-critical battery system that comprises one or more qualified battery sources.

2. The electrical distribution system of claim 1, wherein the first plurality of AC loads comprise engineered safety feature (ESF) electrical loads, and the one or more non-qualified battery sources of the first critical battery system comprise valve regulated lead acid (VRLA) batteries.

3. The electrical distribution system of claim 1, wherein the second plurality of AC loads comprise active post-accident monitoring (PAM) electrical loads and common electrical loads, and the one or more qualified battery sources comprise vented lead acid (VLA) batteries.

4. The electrical distribution system of claim 3, wherein the non-critical battery system comprises:

a first battery train electrically coupled to a first channel of the second AC power bus; and

a second battery train electrically coupled to a second channel of the second AC power bus, each of the first and second battery trains comprising one or more qualified battery sources that comprise VLA batteries.

5. The electrical distribution system of claim 4, further comprising a third battery train electrically coupled to both of the first and second channels of the second AC power bus, the third battery train comprising one or more qualified battery sources that comprise VLA batteries.

6. The electrical distribution system of claim 1, wherein the first critical battery system is sized to supply AC power to the first plurality of AC loads for about 24 hours based on a loss of electrical power from the primary AC power source.

7. The electrical distribution system of claim 1, wherein the non-critical battery systems is sized to supply AC power to the second plurality of AC loads for about 72 hours based on a loss of electrical power from the primary AC power source.

8. The electrical distribution system of claim 1, further comprising:

a third AC power bus that is electrically coupled to the primary AC power source, the first plurality of AC loads, and a second critical battery system that comprises one or more non-qualified battery sources.

9. The electrical distribution system of claim 1, wherein each of the nuclear power systems comprises a passively cooled modular nuclear reactor.

10. A method for providing power to a nuclear power plant, comprising:

providing at least one primary alternating current (AC) power source;

providing a first plurality of AC loads of a plurality of nuclear reactor systems of the nuclear power plant, each of the first plurality of AC loads comprising a critical electrical load of the plurality of nuclear reactor systems that is configured to fail to a safety position based on a loss of electrical power from the primary AC power source;

electrically coupling a first AC power bus to the primary AC power source, the first plurality of AC loads, and a first critical battery system that comprises one or more non-qualified battery sources;

providing a second plurality of AC loads of the plurality of nuclear reactor systems, each of the second plurality of AC loads comprising a non-critical electrical load of the plurality of nuclear reactor systems; and

electrically coupling a second AC power bus to the second plurality of AC loads and a non-critical battery system that comprises one or more qualified battery sources.

11. The method of claim 10, wherein the first plurality of AC loads comprise engineered safety feature (ESF) electrical loads, and the one or more non-qualified battery sources of the first critical battery system comprise valve regulated lead acid (VRLA) batteries.

12. The method of claim 10, wherein the second plurality of AC loads comprise active post-accident monitoring (PAM) electrical loads and common electrical loads, and the one or more qualified battery sources comprise vented lead acid (VLA) batteries.

13. The method of claim 12, further comprising:

electrically coupling a first battery train of the non-critical battery system to a first channel of the second AC power bus; and

electrically coupling a second battery train of the non-critical battery system to a second channel of the second AC power bus, each of the first and second battery trains comprising one or more qualified battery sources that comprise VLA batteries.

14. The method of claim 13, further comprising:

electrically coupling a third battery train of the non-critical battery system to both of the first and second channels of the second AC power bus, the third battery train comprising one or more qualified battery sources that comprise VLA batteries.

15. The method of claim 10, further comprising:

sizing the first critical battery system to supply AC power to the first plurality of AC loads for about 24 hours based on a loss of electrical power from the primary AC power source.

16. The method of claim 10, further comprising:

sizing the non-critical battery systems to supply AC power to the second plurality of AC loads for about 72 hours based on a loss of electrical power from the primary AC power source.

17. The method of claim 10, further comprising:

electrically coupling a third AC power bus to the primary AC power source, the first plurality of AC loads, and a second critical battery system that comprises one or more non-qualified battery sources.

18. The method of claim 10, further comprising:

detecting a loss of primary AC power from the at least one primary AC power source;

adjusting at least a portion of the first plurality of AC loads to their respective safety positions;

supplying AC power to the portion of the first plurality of AC loads from the one or more non-qualified battery sources through the first AC power bus; and

supplying AC power to the second plurality of AC loads from the one or more qualified battery sources through the second AC power bus.

19. The method of claim 18, further comprising:

detecting a restoration of primary AC power from the at least one primary AC power source;

supplying AC power to the portion of the first plurality of AC loads from the at least one primary AC power source through the first AC power bus; and

supplying AC power to the second plurality of AC loads from the at least one primary AC power source through the second AC power bus.

20. An electrical power system for a nuclear power facility comprising:

an active alternating current (AC) power bus configured to be electrically coupled to a plurality of engineered safety feature (ESF) loads of a plurality of nuclear power systems, each of the ESF loads configured to fail to a safe position upon loss of primary AC power;

a critical battery system electrically coupled to the active AC bus, the critical battery system comprising a plurality of valve regulated lead acid (VRLA) batteries; and

a primary AC power source electrically coupled to the active AC bus.

21. The system of claim 20, further comprising:

a common AC power bus configured to be electrically coupled to a plurality of comprise active post-accident monitoring (PAM) electrical loads and common electrical loads of the plurality of nuclear power systems; and

a passive battery system electrically coupled to the common AC bus, the passive battery system comprising one or more vented lead acid (VRLA) batteries.

22. The system of claim 20, wherein the critical battery system comprises a first portion of the plurality of VRLA batteries and a second portion of the plurality of VRLA batteries, each of the first and second portions of the plurality of VRLA batteries electrically coupled separately to the active AC power bus through respective switches.