This standard establishes time response design criteria for safety-related operator
actions to be used in the design of light water
reactor (LWR) nuclear power plants. The criteria are used to determine the minimum response time intervals for safety-related operator actions
that are taken to mitigate design basis events (DBEs) which result in an automatic reactor trip.
This standard specifies time requirements that
are to be met to receive credit in the safety
analysis for operator actions that initiate or
control safety-related functions.
Specifically, the criteria provide bases:
(1) For establishing certain requirements for
determining whether a particular action to initiate or control a safety-related system might be accomplished by operator action or must be accomplished by an automatic action.
(2) For determining when design modifications can obviate the need for automatic actions that would otherwise be required.
(3) For general guidance for hardware, such as instrumentation, controls, indicators, and
annunciators necessary to support safety-related operator actions.
ANS 58.8-1994(R2008) history
1970ANSI/ANS 58.8-2019 Time Response Criteria for Manual Actions at Nuclear Power Plants