Power Systems

Network Systems Engineering Corp. (NSEC) has extensive experience with the design and implementation of power systems at nuclear power stations. These systems are designed to meet all regulatory requirements, including:

  • IEEE Standard 308-1980, Standard Criteria for Class 1E Power Systems for Nuclear Power Generating Stations
  • NUREG/CR-0509: Emergency Power Supplies for Physical Security Systems

NSEC can develop comprehensive power system specifically designed to address specific plant system and regulatory requirements. Our engineers work with our Clients to develop the following:

  1. Conceptual Design

The conceptual design starts with the development of a block diagram depicting the proposed power distribution system. In order to determine the minimum size for the load centers including any uninterruptible power supplies, a preliminary list of is generated using conservative load estimates. A one-line operating diagram is then created to depict the overall distribution system.

  1. Preliminary Detailed Design

During the Design Phase, a detailed equipment list is created for all UPS and non-UPS equipment utilizing conservative load estimates. The conservative sizing of the UPS is verified and the number of load centers and recommended locations is identified. Optimal voltage levels for the power distribution system is then determined. The detailed load list is utilized to determine the minimum size requirements for power feeder cables. Conduit size is determined based on National Electrical Code requirements. Conduit and cable installation drawings are then developed along with associated circuit schedules. A preliminary three-line diagram is also created.

A preliminary load flow model of the security power distribution system can then be developed using OTI’s Electrical Transient Analysis Program (ETAP). Critical equipment design characteristics such as short circuit current levels, cable size and voltage drop between source and load is evaluated using the ETAP model.

A comprehensive list of design issues affecting other systems (for example, HVAC loading, fire loading, ventilation requirements, and so on) or affecting equipment operation (that is,  battery room ventilation, diesel fresh air intake, diesel fuel oil venting) is also be developed.

  1. Equipment Selection

NSEC will work with its Clients to select required power system equipment that meets the requirements of the Preliminary Detailed Design. Equipment to be addressed includes:

  • Automatic Transfer Switches
  • Battery
  • Battery Rack
  • Battery Charger
  • Uninterruptible Power Supply
  • Load Centers
  • Diesel generator

NSEC will support its Clients during the equipment procurement process, including interfacing with vendors, developing procurement specifications/drawings, and evaluating vendor quotations.

  1. Final Detailed Design

NSEC will create the following design/construction documents to support installation of the power system:

  1. Electrical Connection Drawings
  • One-line diagrams
  • Three-line diagrams
  • Elementary wiring diagrams
  • Control schematics
  • Circuit schedules
  1. Equipment Mounting Drawings
  • Battery Rack
  • Automatic Transfer Switch
  • Battery Charger
  • Uninterruptible Power Supply
  • Load Centers
  1. Miscellaneous Drawings
  • Load Center Schedules
  • Equipment alarm and tamper switch connection diagrams
  1. System Analyses

NSEC can also perform a complete analysis of the power system, including the analyses:

  • Coordination analysis
  • Short circuit analysis
  • Arc flash analysis
  • Voltage drop analysis
  • Battery sizing calculation
  • Battery charger sizing calculation
  • Battery hydrogen generation calculation
  • Heat generation calculations (based on equipment locations)
  • Diesel generator starting capability
  • Diesel generator fuel consumption

NSEC engineers can develop all plant change documentation in accordance with Plant Procedures. Our engineers are fully cognizant of all regulations affecting the implementation of plant equipment.

NSEC maintains a fully qualified Appendix B Quality Assurance Program and is capable of performing engineering design work on “safety-related” systems. NSEC also maintains a fully qualified Safeguards Information Program which meets all aspects of 10CFR73.21.

See Experience Summary for other information.