Document: NUREG-0800
Document ID: e1169529-d2cb-4947-9efe-b23d927f4aa9
Document Type: srp
Title: NUREG40800
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052350520.pdf
Revision Date: 2023-06
Chapter: 8
Section ID: 8
CFR Part: 
CFR Title: 

Content:
ltage protection a per bus basis to preclude source; utilized and shall be physically connected to the Class 1E switchgear. be provided for each division of shall include coincidence logic on spurious trips of the offsite power 4) The voltage sensors shall automatically initiate the disconnec- tion of offsite power sources whenever the voltage set point and time delay limits (cited in item L.b.2 above) have been exceeded; 5) Capability for test and calibration during power operation shall be provided. 6) Annunciation must be provided in the control room for any bypasses incorporated in the design. d) The Technical Specifications shall include limiting conditions for operations, surveillance requirements, trip setpoints with minimum and maximum limits, and allowable values for the second-level volt- age protection sensors and associated time delay devices. 2. The Class 1E bus load shedding scheme should automatically prevent shedding during sequencing of the emergency loads to the bus. The load shedding feature should, however, be reinstated upon completion of the load sequenc- ing action. The technical specifications must include a test requirement to demonstrate the operability of the automatic bypass and reinstatement features at least once per 18 months during shutdown. In the event an adequate basis can be provided for retaining the shed feature during the above transient conditions, the setpoint the Technical Specifications for the first level of undervoltage tion (loss of offsite power) must specify a value having maximum minimum limits. The basis for the setpoints and limits selected documented. load value in protec- and must be 3. The voltage levels at the safety-related buses should be optimized for the maximim and minimum load-conditions that are expected throughout the anticipated range of voltage variations of the offsite power sources by appropriate adjustment of the voltage tap settings of the intervening transformers. The tap settings selected should