ML20217M487

Proposed Tech Specs Changing Order of Channel Rotation During Outage for Scheduling Flexibility,While Still Requiring Rotation Schedule to Be Established for Operating Cycle

ML20217M487
Person / Time
Site:	Arkansas Nuclear
Issue date:	04/28/1998
From:	ENTERGY OPERATIONS, INC.
To:
Shared Package
ML20217M484	List: 1CAN049806, Application for Amend to License DPR-51,changing Order of Channel Rotation During Outage for Scheduling Flexibility, While Still Requiring Rotation Schedule to Be Established for Operating Cycle ML20217M487
References
NUDOCS 9805050017
Download: ML20217M487 (3)

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Proposed ANO-1 Technical Specification Bases Pages; I

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9905050017 990429 PDR 'ADOCK 05000313 P PDR

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BASES (continued) n Under the terms of this specification, the more resti 'ctive requirements of the Technical Specifications take precedence over the ASME Boiler and br'essurd Vessel Code-and applicable Addenda. The requirements of Specification 4.0.4 to perform surveillance activities before entry into an operational mode or other specified condition takes precedence over the ASME Boiler and Pressure Vessel Code provision which allows pumps and valves to.be tested up to one week after return to normal operation. The Technical Specification definition of OPERABLE does not allow a grace period before a component, that is not capable of performing its specified function, is declared inoperable and takes precedence over the ASME Boiler and Pressure Vessel Code provision which allows a valve to be incapable of performing its specified function for up to-24 hours before being declared inoperable.

4.1 Bases l Check Failures such as blown instrument fuses, defective indicators, faulted amplifiers which result in " upscale" or "downscale" indication can be easily recognized by simple observation of the functioning of an instrument or system. Furthermore, such failures are, in many cases, revealed by alarm or annunciator Action. Comparison of output and/or state of independent channels measuring the same' variable supplements this type of built-in surveillance. Based on experience in operation of both conventional and nuclear plant systems, when the plant is in operation, the minimum checking frequency stated is deemed adequate for reactor system instrumentation.

Calibration Calibration shall be performed to assure the presentation and acquisition of accurate information. The nuclear flux (power range) channels shall be  !

calibrated at least twice weekly (during steady state operating conditions) against a heat balance standard to compensate for instrumentation drift. During nonsteady state operation, the nuclear flux channels shall be calibrated d .ily to compensate for instrumentation l drift and changing rod patterns and core physics parameters.

Amendment No. 161 67e Revised by NRC Letter Dated

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Other channels are subject only to " drift" errors induced 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

're*calibfation is performed once every 18 months.

Substantial calibration shifts within a channel (essentially a channel failure) will be revealed during routine checking and testing procedures.

Thus, minimum calibration frequencies for the nuclear flux (power range) channels, and once ev for the process system channels is considered acceptable,ery

'. 18 months Testing on-line testing of reactor protective channel and EFIC 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 minimize the likelihood of the same systematic test errors being introduced into each redundant channel.

All reactor protective channels will be tested 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 channels. A rotation will then be established to test the first Channel one week after startup, the second Channel two weeks after startup, the third channel three weeks after startup, and the fourth Channel four weeks after startup.

The established reactor protective system instrumentation and EFIC test cycle is continued with one channel's instrumentation tested each week.

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, after which the trip test cycle is started again.

Amendment No. 24, 91 68 Revised by NRC Letter Dated-4/12/01