ML20049J238

Safety Evaluation Supporting Amend 72 to License DPR-3

ML20049J238
Person / Time
Site:	Yankee Rowe
Issue date:	03/08/1982
From:	Office of Nuclear Reactor Regulation
To:
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ML20049J232	List: ML20049J231 ML20049J235 ML20049J238 ML20049J240
References
NUDOCS 8203120293
Download: ML20049J238 (2)

Text

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4 3/4.2 POWER DISTRIBUTION LIMITS

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PEAK LINEAR HEAT GENERATION' RATE LIMITING CONDITION FOR OPERATION 3.2.1 The peak linear heat generation rate (LHGR) shall not exceed the limits of Figure 3.2-1 during steady state operation.*

l APPLICABILITY:

MODE 1.

ACTION:

With the peak LHGR exceeding the limits of Figure 3.2-1; Within 15 minutes reduce THERMAL POWER to not more than that a.

fraction of the THERMAL POWER allowable for the main coolant pump combination in operation, as expressed telow:

Fracticn of THERMAL POWER =.

Limitino LHGR Peak Full Power LHGR b.

Within 4 hcurs reduce the Power Range and Intermediate Pcwer Range Neutren Flux high trip setptint to < 10S% of the fraction of THERMAL POWER allcwable for the main coolant pump combir.ation.

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SURVEILLANCE REOUIREMENTS I

4.2.1.1 The peak LHGR shall be determined to be within the limits of Figure 3.2-1 using incere instrumentation to obtain a pcwer distribution map:

Priortoinitialoperationabove75%ofRATEdTHERMALPOWER s.

after each fuel loading, and b.

At least once per 1,000 EFPH.

The provisions of Specification 4.0.4 are not applicable.

c.

• 0peration in the 3-Leep mode is not permitted uritil appropriate LOCA actlyses for this mcde have been approved by the NRC.

YANKEE-ROWE 3/4 2-1 AmendmentNo.ff,'g'72 8203120293 820308 PDR ADOCK 05000029 P

PDR I

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[0l!ER DISTRIl!UTIOiJ !.!MI TS SURVE!!.LA JCE uEQUIREME!1TS (Cont inued) 4.2.1.2 The below factors shall be included in the calculation of peak full power LHCR:

te.

Heat flux power peaking factor, Fy,measuredusingincore power > 10%.

inst rumentation a t a b.

Effect of inserting the control group f rom its position a-t the time of measurement to it s insertion limit, F1 as shown in Figure 3.2-2.

The rod insertion limit is shown in Figure 3.1-1.

c.

The multiplier for xenon redistribution is a f unction of core lif etine as given in Figure 3.2-3.

In addition, if control rod Group C is inserted below 75 inches, allowable power may not be regained until power has been at a reduced level defined below for at least twenty-f our hours with control rod Group C between 75 and 90 inches.

Reduced power = allowable f raction of full power times multiplier given in Figure 3.2-4.

Exceptions:

1.

If the rods are inserted below 75 inches and power does not go below the reduced power calculated above, hold at the lowest attained power level for at least twenty-four hours with control rod Group C between 75 and 90 inches before returning to allowable power.

2.

If the rods are inserted below 75 inches and ero power is held for more than fourty-eight hours, no reduced power level need be held on the way to the allowable f raction of f ull power.

d.

Shortened stack height factor, 1.009.

e.

'casurement uncertainty 1

1.05, when at least 17 incore detection system neutron detector j

thimble s a re OPERABLE, or 2.a.

1.068, when less than 17 incore detection system neutron detector thimbles are OPERABLE, or b.

1.080, when less than 12 incore detection system neutron detection thimbles are OFERABLE.

Y A::KE E-RO'.!E 3/4 2-2 A.me n d me n t y',,53',

72

POWER DISTRIBUTION l.IMITS SURVE L LLANCE REQUIREMENTS 4.2.2.1 F shall be determined to be within its limit by:

q Using the movable incore detectors to obtain a power distribution map:

a.

1.

Prior to initial operation above 75% of RATED THERMAL POWER a f ter each f uel loading, ano 2.

At least once per 1000 Effective Full Fower Hours.

b.

Increasing the measured F component of t'he power distribution map q

by:

1.

4% to account for engineering tolerances,

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2.

5%, when at least 17 incore detection system -neutron detector thimbles a re OPERABLE, to accour.t for measurement uncertainty, I

6.8%, when less than 17 incore detec' tion' system neutron 3.a.

detector thimbles are OPERABLE, to account for measurement uncertainty, b.

8.0%, when less than 12 incore detection system neutron detector thimbles a re OPERABLE, to z.ccount for measurement uncertainty, and 4.

3% to account for fuel densification.

4.2.2.2 When F is measured pursuant to Specification 4.10.2.2, an overall shall be obtained f rom a power distribution map and increased by:

c measured F q 1.

4% to account for engineering tolerances, 2.

5%, when at least 17 incore detection system neutron detector thimbles are OPERABLE, to account for measurepent uncertainty, 3.a.

6.8%, when les s the n 17 incore de tec t io:- syster: neutron detector thimbles are OPERABLE, to account for measurement uncertainty, b.

8.0%, when less than 12 incore detection system n.eutron detector thimbles are OPERABLE, to account for measurement uncertainty, and 4.

3% to account for f uel densification.

are not applicable.

4.2.2.3 The provisions of Specification 4.0.4 YANKEE-ROWE 3/4.2-9, Amc.td me n t No. % 72

c-POWER DISTRIBUTION LIMITS hUCLEAR ENTHALPY RISE HOT CHANNEL FACTOR - F g LIMITINC CONDITION FOR OPERATION

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3.2.3 F

shall be limited by the following relationship:

H g _ 4 80 D.0 + 0.2 0-W 1

F where P = THERMAL POWERRATED THERMAL POWER, and APPLICABILITY:

MODE 1 ACTION:

With F exceeding its limit:

g a.

Reduce THERMAL POWER to less than 50% of RATED THERFAL POWER i

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within 2. hours and reduce the Power Range and Intermediate Power Range Neutron Flux-high trip setpoints to < 55% of PATED THERMAL POWER within the nex't a bours, I

b.

Demonstrate through in-core mapping that F.u is w'ithin its limit within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> af ter exceeding the timit or reduce THERMAL POWER to less than 5% of RATED THERMAL POWER within the, next 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />, and i

i Identify and correct the cause of the out of limit condition c.

prior to increasing THERMAL POWER above the reduced limit required by a or b, abovg; subsequent POWER OPERATION may proceed l

provided that F,,, is demonstrated through in-core napping to be within its lir:iit at a nominal 50", of RATED THERFAL POWER prior to exceeding.this THERMAL POWER, at a nominal 75" of RATED THERFAL POWER prior to exceeding this THERFAL power and within.24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> af ter attaining 95% or greater RATED THERFAL POWER.

i YANKEE-ROWE 3/42-i0

POWEl: D I STR II?UT IOf LIMITS SURVEILLAtCE REQUIREMENTS 4.2.3.1 Fygshallbedeterminedtobewithinitslimit by using the movable incore detectors to obtain a power distribution map:

Prior to operation above 75% RATED TilEP. MAL POWER af ter each f uel a.

loading, and b.

At least once per 1000 Effective Full Power Hours.

not applicable.

c.

The provisions of Specification 4.0.4 are 4.2.3.2 ThemeasuredFy;;of4.2.3.1aboveshallbeincreased, for measurement uncertainty, by:

a.

5%, when at least 17 incore detection syatem neutron detector thimbles a re OPERABLE, or b.

6.8%, when less than 17 incore detection system neutron detector thimbles a re OPERABLE, or 8.0%, when less than 12 incore detection system neutron detector c.

thii,bles a re OPERABLE.

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Y A NKE E-R O'.JE 3/4 2 Acendment tio. j,f, p3', 72

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l POWER DISTRIBUTION LIMITS

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DNB PAR METERS LIMITING CONDITION FOR OPERATION 3.2.4 'The following DNB related parameters shall be maintained within the limits shown on Table 3.2-1:

a.

Main Coolant System Inlet Temperature.

b.

Main Coolant System Pressure c.

Main Coolant System Total Flow Rate APPLICABILITY: MODE 1 ACTION:

With any of the above parameters exceeding its limit, restor s the param-eter to within its limit within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> or reduce -THERMAL POWER to.less than 5% of RATED THERMAL POWER within the next 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.

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SURVEILLANCE REQUIREMENTS 4.2.4.1 Each of the parameters of Table 3.2-1 shall be verified'to be within their limits at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

4.2.4.2 The Main Coolant System tocal flow rate shall be determined to be w,ithin' its limit b; measurement at least once per 18 months.

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<l YANKEE-ROWE 3/4 2 12

INSTRU?tENTATION INCORE DETECTION SYSTE!!

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a 3.3.3.2 The incore detection system ; hall be OPERABLE with:

a.

At least twelve (12) neutron detector thimbles OPERABLE, b.

A minimum of two (2) OPEPABLE neutron detector thimbles per core quadrant, c.

Sufficient OPERABLE movable neutron detectors, drive, and readout equipment to map these thimbles, and d.

At least ten (10) OPERABLE radial position thermocouples with an OPERABLE thermocouple in at least one of the two calculated hottest instrumented fuel assemblies.

EXCEPTION:

For Cycle 15, Items a. and b. above are not requf ted if operation is at or beyond 4000 ftWD/rff,U.,However, there should be at least nine (9) detector thimbles OPERABLE and a minimum of one (1) OPERABLE neutron detector thimbles per quadrant.

APPLICABILITY: When the incore detection system is used for core power distribution measurements.

ACTION:

With the incore detection system inoperable, do not use the system for the above. applicable monitoring or calibration functions. The provisions of Specifications 3.0.3 and 3.0.4 are not applicablq.

SUE'.'EILLANCE REOUIREMENTS 4.3.3.2 The incore neutron detectors shall be demonstrated OPERABLE by normali::ing each detector output to be used within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> prior to its use for core power distribution =casurements.

YANKEE-RCUE 3/4 3-23 Amendment flo. #f,.5{ 72

s INSTRUMENTATION METEOROLOGICAL INSTRUMENTATION LIMITING CONDITION FOR OPERATION I

3.3.3.3 'The meteorological monitoring instrumentation channels shown in Table 3.3-5 shall be OPERABLE.,

APPLICABILITY:

At all times.

ACTION:

h'ith one or more required meteorological monitoring channels inoperable i

tor more than 7 days, prepare' and submit a Special Report to the Commission I

pursuant to S'pecification 6.9.6 within the next 10 days outlining the cause of the malfunction and the plans for restoring the channel (s) to OPERABLE status.

The provisions of Specifications 3.0.3 and 3.0.4 are not applicablp.

s SURVEILLANCE REOUIREMENTS f

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" 3.3.3 Each of the above meteorological monitoring instrumentation channels shall be demonstrated OPERABLE by the performance of the CHANNEL CHECK and CHANNEL CALIBRATION operations at the frequencies shown in Table 4.3-4.

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f T ANKE E-ROWE 3/4 3 g(

o UNITED STATES y

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NUCLEAR REGULATORY COMMISSION

,g 6# g E WASHINGTON, D. C. 20S$5 v

e SAFETY EVALUATION BY THE OFFICE OF NUCLEAR-REACTOR REGULATION SUPPORTING AMENDMENT NO. 79 TO FACILITY OPERATING LICENSE NO. DPR-3 YANKEE NUCLEAR POWER STATION (YANKEE-ROWE)

YANKEE ATOMIC ELECTRIC COMPANY l

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DOCKET NO. 50-29

1.0 INTRODUCTION

By letters dated February 9,1982 and February 25, 1982 Yankee Atomic Electric Company (the licensee) requested a change to the Technical Specifications' appended to Facility Operating License No. DPR-3 for the Yankee Nuclear Power Station. This change would reduce the minimum number of operable incore neutron detector thimbles for the remainder i

of Cycle 15.

The measurement uncertainty would be increased if fewer than the present minimum number of detector thimbies were used.

2.0 DISCUSSION AND EVALUATION The present technical specification requires that twelve neutron detector thimbles be operable with at least two per core quadrant whenever the system is used for core power distribution measurements. The proposed technical specification would require a minimum of nine neutron detector thimbles with at least one per core quadrant. The measurement uncertainty would be increased from 6.8 percent to 8.0 percent.

The incore neutron detector system is required to be used every 1000 MWD /MTU for core power distribution measurements.

The measured linear heat generation l

rate and peaking factors obtained from these power distribution measurements are compared with technical specification limits.

Since Yankee now has 'only twelve. detector thimbles operable, the technical specification change is needed so they can conplete the ' cycle if additional detector thimbles should fail (thirteen were operable when Cycle 15 began).

A similar technical specification change was made from a minimum of 17 to 12 in 1978 (Amendment No. 53, issued on November 24, 1978'). At that time the measurement uncertainty was increased from 5 percent to 6.8 percent. The proposed technical specification change is only for the remainder of Cycle 15 because Yankee plans to repair the neutron detector thimbles during the next refueling outage. At least 16 thimbles should be operable at the begin-(

ning of Cycle 16.

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z,,,

We have reviewed how incore measurements are mad and how the various core parameters are calculated. The additional measurement uncertainty is appropriate.

In addition, if detectors fail such that a particular area of the core is not-well measured, the quadrant rotation option as well as the normal full core method of calculating parameters will be used. The most con 3ervative values would then be used to compare,with technical specification li.mits. We have concluded that this is an acceptable mea'ns for determining the power distribution and that the technical specifi-cation change is, therefore, acceptable.

3.0 ENVIRONMENTAL CONSIDERATION

We have determined that the amendment does not a' Sorize a change in effluent types or total amounts nor an increase in power level and will not result in any significant environmental impact.

Having made this determination, we have further concluded that the amendment involves an action which is insignificant from the standpoint of environmental impact and, pursuant to 10 CFR 151.5(d)(4), that an envir-onmental impact state-ment or negative declaration and environmental impact appraisal need not be prepared in connection with the issucnce of this amendment.

4.0 CONCLUSION

We have concluded, based on the considerations discussed.above, that:

(1) because the amendment does not involve a significant increase in the probability or consequences of accidents previously considered and'does not involve a significant decrease in a safety margin, the amendment does not invol',e a significant hazards consideration, (2) there is reasonable assurance that the health and safety of the public will not be endangered

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by operation in the proposed manner, and (3) such activities will be conducted in compliance with the Commission's regulations and the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.

- 5.0 ACKNOWLEDGEMENTS The following NRC staff members contributed to this evaluation.

R. Caruso - Operating Reactors Branch #5 M. Chatterton - Core Performance Branch Date:

March 8, 1982 4

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