ML19340A122

Proposed Tech Spec 4.1 Re Operational Safety Review Permitting More Conservative Recalibr of Nuclear Instrumentation

ML19340A122
Person / Time
Site:	Oconee
Issue date:	05/06/1977
From:	DUKE POWER CO.
To:
Shared Package
ML19340A114	List: ML19340A112 ML19340A122
References
NUDOCS 7911250042
Download: ML19340A122 (2)

Text

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i- 4.1 0PERATIONAL SAFETY REVIEW Applicability Applies to items directly related to safety limits and limiting conditions for operation.

Obiective To specify the frequency and type of surveillance to be applied to unit equip-ment and conditions.

Specification 4.1.1 The frequency and type of surveillance required for Reactor Pro-tective System and Engineered Safety Feature Protective System instrumentation shall be as stated in Table 4.1-1.

4.1.2 Equipment and sampling test shall be performed as detailed in Tables 4.1-2 and 4.1-3.

4.1.3 Using the Incore Instrumentation System, a power map shall be made to verify expected power distribution at periodic intervals not to exceed ten gffective full power days.

Bases Failures such as blown instrument fuses, defective indicators, and 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 systems, when the unit ~is in operation, the minimum checking fr4 uency 3 stated is deemed adequate for reactor system instrumentation..

Calibration is performed ~to assure the presentation and acquisition of ac-curate information. The_ nuclear flux'(power range)' channels amplifiers are calibrated (during steady-state operating conditions) when indicated neutron power and core thermal power dif fer by more than two percent. During non-steady-state operation, the nuclear flux enannels amplifiers are calibrated each shift.to compensate for instrumentation drift and-changing rod patterns <

and core physics parameters.

, Channels subject only to " drift". errors induced within the instrumentation itself can tolerate longer intervals between calibrations. Process system

' instrumentation errors induced by drif t can be expected to remain within acceptable' tolerances if recalibration'is performed at the. intervals specified.

Substantial calibration shif ts within a channel (essentially a. channel

-failure) are revealed during routine checking and testiag procedures. Thus, the minimum calibration frequencies set forth are considered acceptable.

4.1-1

_ 7 911250 Cfj2.

o Table 4.1-1 INSTRUMENT SURVEILLANCE REQUIREMENTS . ,

Channel Description Check -Test Calibrate Remarks-

1. Protective Channel NA HD NA Coincidence Logic

2. Control Rod Drive NA M0 NA Trip Breaker

3. _ Power Range Amplifier' ES(l) NA (1) (1) Heat balance check each shif t. Ileat [

balance calibration whenever indi-cated core titermal power' exceeds neutron

-power by more than 2 percent.

4. Power Range ES. H0 M0(1)(2) (1) Using incore instrumentation.-

," (2) Axial offset upper and lower chambers y after each startup if not done pre-w-

vlous week.

5. Intermediate Range ES(l) PS NA (1) When in scrilce.

6. Source Range ES(1) PS NA (1) When in service.

7. Reactor-Coolant' ES HO AN Temperature i

8. liigh Reactor Coolant ES HO AN '--

Pressure

9. Low Reactor Coolant ES M0 AN Pressure

, 10. Flux-Reactor Coolant ES M0 AN Flow Comparator

11. Reactor Coolant Pressure ES M0 AN Temperature Comparator