IEEE 387-2017 pdf download

IEEE 387-2017 pdf download.IEEE Standard for Criteria for Diesel Generator Units Applied as Stand by Power Supplies for Nuclear Power Generating Stations.
3. Definitions
For the purposes of this document, the following terms and definitions apply. The iEEE Standards Dictionary Online should be consulted for terms not defined in this clause.
acceptable: Demonstrated to be adequate by the safety analysis of the plant.
continuous rating (of diesel-generator unit): The electric power output capability that the diesel- generator unit can maintain in the service environment for 8760 h of operation per year with only scheduled outages for maintenance.
design basis event/accident: Postulated events used in the design to establish the performance requirements of the structures, systems, and components. A postulated event or accident that a nuclear facility shall be designed and built to withstand without loss to the systems, structures, and components necessary to improve public health and safety.
design load: That combination of electric loads (kW and kvar), having the most severe power demand characteristic, which is provided with electric energy from a diesel-generator unit for the operation of engineered safety features and other systems required during and following shutdown of the reactor. Design load may include the term power factor.
diesel-generator unit: An independent source of standby electrical power that consists of a diesel-fueled internal combustion engine (or engines) coupled directly to an electrical generator (or generators); the associated mechanical and electrical auxiliary systems; and the control, protection, and surveillance systems.
start demands: All valid and inadvertent starts, including all starts that are followed by load-runs, whether by automatic or manual initiation. Included is a start-only situation where the emergency diesel generator is started, but no attempt is made to load the emergency diesel generator. See the following exeptions:
start demand failures:
• Any failure within the emergency diesel generator system that prevents the generator from achieving a specified frequency (or speed) and voltage within specified time allowance is classified as a valid start failure. For monthly surveillance tests, the emergency diesel generator can be brought to rated speed and voltage in the time recommended by the manufacturer to reduced stress and wear.
• Any condition identified during maintenance inspections (with the emergency diesel generator in the standby mode) that would definitely have resulted in a start failure if a demand had occurred shall count as a valid start demand and failure.
load-run demands: To be valid, the load-run attempt shall follow a successful start and meet one of the following criteria (see the exceptions below):
a) A load-run of any duration that results from a real (i.e., not a test) automatic or manual signal
b) A load-run test to satisfy the plant’s load and duration test specifications
c) Other operations (e.g., special tests) in which the emergency diesel generator is planned to run for at least 1 h with at least 50% of design load
load-run demand failures: A load-nm failure shall be counted when the emergency diesel generator starts but does not pick up the load and run successfully. Any failure during a valid load-run demand shall count (see the exceptions below). For monthly surveillance tests, the emergency diesel generator can be loaded at the rate recommended by the manufacturer to reduce stress and wear. Any condition identified during maintenance inspections (with the emergency diesel generator in the standby mode) that definitely would have resulted in a load-nm failure if a demand had occurred shall count as a valid load-nm demand and failure.
Exceptions: Unsuccessful attempts to start or load-mn shall not count as valid demands or failure when they can definitely be attributed to any of the following:
a) Any operation of a trip that would be bypassed in the emergency operating mode (e.g., high coolingwater temperature trip)
b) Malfunction of equipment that is not required to operate during the emergency operating mode (e.g., synchronizing circuitry).