ML20066J761
| ML20066J761 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 02/20/1991 |
| From: | ENTERGY OPERATIONS, INC. |
| To: | |
| Shared Package | |
| ML20066J758 | List: |
| References | |
| NUDOCS 9102270002 | |
| Download: ML20066J761 (2) | |
Text
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TECilNICAL SPECIFICATION BASIS CilANGES s
t, r2 9102270002 910220
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10ther channels are subject only to "drif t" errorv 3nduced within the
~
" '. instrumentation itself and, consequently-can tolerate longer intervals between calibrations.
process system instrumentation errors induced by
. drift can be expected to remain within acceptable tolerances if recalibration is performed once every 18 months.
Substantial calibration sFifts within a channel (essentially a channel failure) will be revealed during routine checking and testing procedures.
Thus, minimum calibration frequencies for the nucicar flux (power range) channels, and once every 18 months for the process system channels is considered acceptable.
lesting On-line t.esting of reactor protective channel and EPIC channels is required once every 4 weeks on a rotational or staggered basis.
The rotation scheme is designed to reduce the probability of an undetected failure existing within the system and to minimire the likelihood of the same systematic test errors being introduced into each redundant channel.
The rotation schedule for the reactor protective channels is as follows:
Channels'A, B, C, D Before Startup if the individual channel rotational frequency has been discontinued or if outage activities could potentially have affected the operability of one or more channel Channel A One Week After Startup Channel B Two weeks After Startup Channel C Three Weeks After Startup Channel 0-Four Weeks After Startup The reactor protective system instrumentation and'EFIC test cycle is continued with one channel's instrumentation tested each'wcek.
Upon detection of a failure that prevents trip action, all instrumentation associated with the protective channels will be tested after which the rotational test cycle is started again.
If actuation of a safety
. channel occurs, assurance will be required that actuation was within the limiting safety system setting.
The protective channels coincidence logic and control rod drive trip
. breakers are trip tested every four weeks.
The trip test checks all
. logic combinations and is to be performed on a rotational basis.
The logic and breakers of the four protective channels shall be trip tested prior to startup and their individual channels trip tested on a cyclic basis.
Discovery of a failure requires the testing of all channel logic and breakers, af ter which the t. rip test cycle is started again.
l i
l Amendment No. 25,/91 68