ML17304A339

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Proposed Tech Specs,Revising Section 2.2.1 Re Core Protection Calculator Auxiliary Trip Setpoint
ML17304A339
Person / Time
Site: Palo Verde  Arizona Public Service icon.png
Issue date: 08/08/1988
From:
ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:
Shared Package
ML17304A338 List:
References
NUDOCS 8808180273
Download: ML17304A339 (4)


Text

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'" SAFETY LIMITS ANO LIMITING SAFETY SYSTEMS SETTINGS BASES e

S DNBR " Low (Continued)

'-.The DNBR, the trip variable, calculated by the CPC incorporates various uncer-

".- .," tainties to assure a trip is initiated prior "to violation of tuel design limits.routines and dynamic compensation These uncertainties and dynamic compensa-

,tion routines ensure that a reactor trip occurs when the calculated core ONBR-

.
, is sufficiently greater than 1.24 such that the decrease in calculated core
"','">'..', '-.'.. DNBR after the trip will not result in a violation of the DNBR

" ';","'" -'" CPC uncertainties related to DNBR cover CPC input measurement uncertainties, Safety Limi.

'.-; algorithm modelling uncertainties, and

"".., ".-',.uncertainties. Dynamic compensation is computer equipment processing provided in the CPC calculations for the effects of coolant transport delays, core heat flux delays (relative to

" changes in core power), sensor time delays, and protection system equipment

. time delays.

',indicated 4t I

The DNBR algorithm. used in the CPC is valid only within the limits be'tow and operation outside of these limits will result in a CPC initiated trip.

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a. 'CS Cold Leg Temperature-Low > 470'F
b.  ; RCS Cold Leg Temperature-High < 610 F

'-'. . .Axial Shape Index-Positive . Not more positive than + 0.5 Axial Shape Index.-Negative . Not more negative than - 0.5 e.'ressurizer Pressure-Low >.1860 psia

':.  ; .,~'~', f. "'ressurizer Pressure-High < 2388 psia Integrated Radial Peaking Factor-Low cll ~n an ce *

h. Integrated Radial Peaking +,00 Factor High .28

,", .",'- i. '. equality Hargin-Low

.','. 'team Generator Level - Hi h I

. The Steam Generator Level " High trip is provided to protect the turbine

,... 'from excessive moisture carry over. Since the turbine is automatically

';-;-',"'-"'.tripped when the reactor is tripped, this trip provides a reliable means for

,"g 'roviding protection to the turbine from excesssive moisture carryover. This

'=

.trip s setpoint does not correspond to a safety limit, and provides protection in the event of excess feedwater flow. The setpoint is identical to the main

"-',.'.-"; " steam isolation setpoint. Its functional capability at the specified trip setting enhances the overall reliability of the reactor protection system.

8808i80273 880808

  • PDR AOOCN, 95000528 p PNU t

PALO VERDE - UNIT 1 B 2-6 'AMENDMENT NO. 24

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)NTROLLED BY USER Q

~s SAFETY LIMITS ANO LIMITING SAFETY SYSTEMS SETTINGS BASES DNBR - Low (Continued)

The ONBR, the trip variable, calculated by the CPC incorporates various uncer-tainties and dynamic compensation routines to assure a trip is initiated prior to violation of fuel design limits. These uncertainties and dynamic compensa-tion routines ensure that a reactor trip occurs when the calculated core DNBR is sufficiently greater than 1.24 such that the decrease i'n calculated core DNBR after the trip will not result in a violation of the ONBR Safety Limit.

CPC uncertainties related to ONBR cover CPC input measurement uncertainties, algorithm modelling uncertainties, and computer equipment processing uncertainties. Dynamic compensation is provided in the CPC calculations for the effects of coolant transport delays, core heat flux delays (relative to changes in core power), sensor, time delays, and protection system equipment time delays.

The ONBR algorithm used in the CPC is valid only within the limits indicated below and operation outside of these limits will result in a CPC initiated trip.

Parameter UUiUY1

a. RCS Cold Leg Temperature-Low > 470'F
b. RCS Cold Leg Temperature-High < 610 F C. Axial Shape Index-Positive Hot more positive than + 0.5
d. Axial Shape Index-Negative Not more negative than - 0.5
e. Pressurizer Pressure-Low > 1860 psia
f. Pressurizer Pressure-High < 2388 psia
g. Integrated Radial Peaking Factor-Low > 1.28 ch<~g~ + O
h. Integrated Radial Peaking Factor-High zP QQ equality Margin-Low Steam Generator Level - Hi h The Steam Generator Level - High trip is provided to protect the turbine from excessive moisture carry over. Since the turbine is automatically tripped when the reactor is tripped, this trip provides a reliable means for providing protection to the turbine from excesssive moisture carryover. This trip's setpoint does not correspond to a safety limit, and provides protection in the event of excess feedwater flow. The setpoint is identical to the main steam isolation setpoint. Its functional capability at the specified trip setting enhances the overall reliability of the reactor protection system.

PALO VERDE - UNIT 2 B 2-6. AMENDMENT NO. 19

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