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Proposed Tech Spec Changes,Modifying Actions & Surveillance Requirement for Tech Spec 3/4.2.4, Quadrant Power Tilt Ratio
	ML20006F444
Person / Time
Site:	Trojan File:Portland General Electric icon.png
Issue date:	02/16/1990
From:	; PORTLAND GENERAL ELECTRIC CO.
To:	;
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ML20006F290	List: ML20006F289; ML20006F442; ML20006F444;
References
	NUDOCS 9002280036
	Download: ML20006F444 (3)
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LCA 193 Attachment B s.

't Page 1 of 4 POWER DISTRIBUTION LIMITS l

QUADRANT POWER TILT RATIO 1

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LIMITING CONDITION FOR OPERATION 3.2.4 THE QUADRANT POWER TILT RATIO sh'all not exceed 1.02.

ARPLICABILITY: MODE 1 ABOYE 50% OF RATEQ THERMAL POWER' ACTION:

a.

With the QUADRANT POWER TILT RATIO determined to exceed 1.02 but < 1.09:

t-Within 2 hour2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months s:

a)

Either reduce the QUADRANT POWER TILT RATIO to L

within its limit, or from RATED THERb%L POWER b)

Reduce THERMAL POWER at least 3Pfor each 15 of indicated -QUADRANT POWER TILT RATIO in excess of 1.0 and similarly reduce the Power Range Neutron Flux-High Trip Setpoints within the next 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months .

3.

Verify that the QUADRANT POWER' TILT RA'rIO is within its -

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limit within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months after exceeding the limit.or reduce THERMAL POWER to less than 50% of RATED THERMAL POWER within the next 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months and reduce the. Power Range Neutron Flux-High Trip setpoints to < 55% of RATED THERMAL POWER within the next 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months .

4.

Identify and correct the cause of the out of limit con-dition prior to increasing THERMAL POWER; subsequent POWER' OPERATION above 50% of RATED THERMAL power may proceed provided that the QUADRANT POWER TILT RATIO is verified for 12 ho n or-l within its limit at least once per hour %ntil verified i-

. acceptable at 955.or greater RATED THERMAL POWER.

b.

With the QUADRANT POWER TILT RATIO detensined to exceed-1.09-1 due to misalignment-of either a control or shutdown rod:

TMert X from RATED THERbRL POWER 2.

leduce THERMAL POWER at least 39'for each 15 of indi-cated QUADRANT POWER TILT RATIO in excess of 1.0, within' E minutes.

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See Special Test Exception 3.10.2.

TROJAN-UNIT 1 3/4 2-10 Anendment No. N h

Q4a rch,3, 19h

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9002280036 900216 PDR ADOCK 05000344 P

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Attachment B-J Page 2 of 4 3

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POWER DISTRIBUTION LIMITf WG CONDITION FOR OPERATION (Continued) 3.

Verify that the OUADRANT POWER TILY RATIO is within its limit within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months af ter exceeding the limit or reduce THERMAL POWER to less than 505 of RATED THERMAL POWER within the next 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months and reduce the Power Range Neutron Flux-Migh trip 5etpoints to 5 555 of RATED THERMAL POWER within the next 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months .

4.[!dentify and correct the cause of the out of limit con-citiore prior to increasing THERMAL POWER; subsequent i

POWER OPERATION above 50% of RATED THERMAL POWER may proceed provided that the QUADRANT POWER TILT RATIO is/ or 72 h0W 04 f

verified within its limit at least once per hou Nun verified acceptable at 955 or greater RATED THERMAL POWER.

i c.

With the QUADRANT POWER TILT RATIO determined to exceed 1.0g due to causes other than the misalignment of either a control or shutdown rod:

1Mert X i

2.

Reduce THERMAL POWER to less than 505 of: RATED THERMAL 1.

POWER within 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months and reduce the Power Range Neutron Flux-High Trip 5etpoints to 1 655 of RATED THERMAL POWER l

7 within the next 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months .

3.

Identify and correct the ccuse of the out of limit con-dition prior to increasing THERMAL POWER: subsequent POWER OPERAT!0N above 50% of RATED THERMAL POWER may proceed provided that the QUADRANT POWER TILT RATIO is verifiedj for 12 how or within its limit at least once per hourWuntil verified at 955 or greater RATED THERMAL POWER.

d.

The provisions of Specification 3.0.4 are not applicable.

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SURVEILLANCE REQUIREMENTS

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4.2.4^ The GUADRANT POWER TILT RATIO shall be determined to be within the L

limit above 505 of RATED THERMAL POWER by:-

a.

Calculating the ratio at least once per 7 days.when the alarn is OPERA 8LE.

I" b.

Calculating the ratio at least once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months during steady state operation when the-alare is inoperable.

c.

Using the movable incere detectors to determine the GUADRANT POWER TILT RATIO at least once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months when one Power IM ott Y Range Channel is inoperable &' THERMAL POWER is > 75 percent of RATED THERMAL POWER.

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TROlAN-UNIT 1 3/4 2-11 Amendment No. 79 O CMay 11, 1H D G2._

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LCA-193J

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.1. -- Calculate the QUADRANT POWER T1LT RATIO at least once per hour untit either:

7 a) The QUADRANT POWER TILT RATIO is reduced to scLthin i

its linLt, or

- b). THERMAL POWER is reduced t.o less than 50% of RATED THERh%L' 7"

PNER.

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,4.2.4.2 ' The QUADRANT POWER TILT RATIO shall b'c detcrmined to be scLthin the.

finLt when above 75 percent of RATED THERhkL POWER with one Power Range Channet inoperable by[using the movable incore detectors-to confirm that.the normatized

st mmetric power distribution, obtained from.the 4 pairs of"stjmmetric thimble j

. Locations,-is consistent with.the indicated QUADRANT POWER -TILT RATIO a.t icast.

.once per;12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months '.

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LCA 193 f

Attachment B

-TI' Page 4 of 4

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F POWER DISTRIBUTION LIMITS BASES i

WhenRCSflowrateandF$Haremeasured,noadditionalallowancesare necessary. prior to comparison with the limits of Figure 3.2-3 agd 3.2-4.

Measurement errors of 3.5% for RCS total flow rate and 4% for FAH have been allowed for in determination of the design DNBR value.

The safety analysis DNBR values include a 14.4% margin for conservatism.

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The offect of rod bow on DNBR has been determined to be a <1.5% penalty.

L5' The available margin more than offsets the effect of rod bow and no penalty is required on FaH or DNBR.

-3/4.2.4 OVADRANT POWER TILT RATIO

.The quadrant power tilt ratio limit assures that the radial power distribution satisfies the design values used in the power capability analysis.

Radial power distribution measurements are made during startup testing and periodically during powe.r operation.

The limit of 1.02 at which corrective action is required provides

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DNB and linear heat generation rate protection with x-y plane power tilts.

A limiting tilt of 1.025 can be tolerated before the margin for uncertainty in F0 is depleted. The limit of 1.02 was selected to provide an allowance l

for the uncertainty associated with the indicated power tilt. y s

The 2-hour time allowance for operation with a tilt condition greater than 1.02 but less than 1.09 is provided to allow identification and correc-tion of a dropped or misaligned rod.

In the event such action does not i

correct the tilt, the margin for uncertainty on Fg is reinstated by reducing the power by 3 percent for each percent of tilt.in excess.of.1.0.

"The Nuclear Instrumenta. tion System atarun setpoints may be set at 1.03 since historicat data has shown that the stue tilt ratio will be less than 1.02.

b TROJAN-UNIT 1 B 3/4 2-5 Amendment 20, ##, 48, 704 (May 24, 19 %

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ML20006F444

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