ML19317D270

Proposed Tech Spec 3.5.2 Re Control Rod Group & Power Distribution Limits & Table 4.1-2 Re Min Equipment Test Frequency

ML19317D270
Person / Time
Site:	Oconee
Issue date:	09/25/1978
From:	DUKE POWER CO.
To:
Shared Package
ML19317D269	List: ML19317D268 ML19317D270
References
NUDOCS 7911190651
Download: ML19317D270 (7)

Text

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3.5.2 Control Rod Group and Power Distribution limits Apolicability This specification applies to power distribution and operation of control rods during power operation.

Objective To assure an acceptable core power distribution during power operation, to set a limit on potential reactivity insertion from a hypothetical control rod ejec-tion, and to assure core suberiticality after a reactor trip.

Specification 3.5.2.1 Shutdown Margin

2. The available shutdown margin shall be greater than 1% ik/k with the highest worth control rod fully withdrawn.

b. If the shutdown margin is less than 1% ik/k, then within 1 houn initiate and continue boration until the required shutdown mar-gin is restored. The requirements of specification 3.5.2.5.c shall be met.

3.5.2.2 Movable Control Assemblies

a. All control (safety and regulating) rods shall be operable and positioned within nine (3) inches of their group average height.

b. A control rod shall be declared inoperable if any of the follow- 1 1

ing conditions exist for that rod:

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1. The control rod cannot be moved due to excessive fric: ton or l mechanical interference, or cannot perform its intended trip function.

2. The control rod cannot be located by either absolute or re- i lative position indication or by in or out limi: ligh s.

3. The control rod is misaligned wi:h i:s group average by more than nine (9) inches.

4. The control rod does not meet the .xercise requirements of Specification 4.1.

5. The control rod does not meet the :od trip insertion times of Specification 4.7.1.

6. The control rod does not meet the rod program verifica ion of Specification 4.7.2.

3.5-6 3e11190 . .- -- .

c. If a control rod is dsclared inoperable by being immovable due to excessive friction or mechanical interference or known to be un-trippable then:

1. Within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> verify that the shutdown margin requirement of Specification 3.5.2.1 is satisfied and,

2. Within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> place the reactor in the hot standby condition.

d. If a control rod is declared inoperable due to causes other than addressed in 3.5.2.2.c above then:

1. Within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> either restore the rod to operable status or,

2. Continue power operation with the control red declared in-operable and

a. Within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> verify the shutdown margin require-ment of Specification 3.5.2.1 with an ad-dicional allowance for the withdrawn worth of the inop-erable rod and,

b. Either reactor thermal power shall be reduced to less than 60% of the allowable power for the reactor coolant pump combination wi:hin 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and the Nuclear Overpower Trip Setpoints, based on flux and flux / flow / imbalance, shall be reduced within the nex: 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> to 65.5% of thermal power value allowable for the reactor coolant pump combination or,

c. Position the remaining rods in the affected group such that the inoperable rod is =aintained within allow-able group average limits of Specification 3.5.2.2.s and the withdrawal limits of Specification 3.5.2.5.c.

e. If more than one control red is inoperable or misaligned, the reactor shall be shut down to the hot standby condition within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

3.5.2.3 The wornhs of single inserted control rods during criticality are limited by the restrictions of Specifi:ation 3.1.3.5 and :he control red position limits defined in Specification 3.5.2.5.

3.5.2.4 Quadrant Power Til

a. Except for physics :ests, the maximum positive quadrant power tilt shall not exceed :he Steady State Limit of Table 3.5-1 during power operation above 15% full power.

b. If the maximum positive quadrant power tilt exceeds the Steady State Limit but is less than or equal to the Transient Lini:

j of Table 3.5-1, then:

i 3.5-7

_ . _ . _ , _ _ _ _ .,. _ ~ _ _ _ , _ _ , _ _ - _ . . _ _ _ _ _ ___ __. _ __.- _ ._. ,_

1. Eithr: tha quadrant powar tilt shall be reduced within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> to within its Steady State Limit or

2. The reactor thermal power shall be reduced below the power level cutoff (as specified in Specification 3.5.2.5) and further reduced 2% thermal power for each 1% of quadrant power tilt in excess of the Steady State Limit, and the Nuclear Overpower Trip Setpoints, based on flux and flux /

flow imbalance, shall be reduced within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> by 2%

thermal power for each 1% til in excess of the Steady State Limit. If less than four reactor coolant pumps are in operation, the allowable thermal power for the reactor coolant pump combination shall be reduced by 2% for each 1% excess tilt.

c. Quadrant power til shall be reduced within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to within its Steady State Limit or,

1. The reactor thermal power shall be reduced within the next 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> to less than 60% of the allowable power for the re-actor coolant pump combination and the Nucles: Overpower Trip Setpoints, based on flux and flux / flow imbalance, shall be re-duced within the next 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> to 65.5% of the thermal power value allowa'ile for the reactor coolant pump combination.

d. If the quadrant power til exceeds the Transient Limit but is less than the Maximum Limit of Table 3.5-1 and if there is a simultaneous indication of a misaligned control rod then:

1. Reactor thermal power shall be reduced within 30 minutes at least 2% for each 1% of the quadrant power til in ex-cess of the Steady State Limit.

2. Either quadrant power tilt shall be reduced within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> to within its Transient Limit or,

3. The reactor thermal power shall be reduced within the next 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> to less than 60% of the allowable power for the re-actor coolant pump combination and the Nuclear Cverpower Trip Setpoints, based on flux and flux / flow imbalance, shall be re-

[ duced within the next i hours to 65.5% of the thermal power l value allowable for the reactor coolant pump combination.

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! e. If the quadrant power tilt exceeds the Transient Limit but is less than the Maximum Limit of Table 3.5-1, due to causes other than simultaneous indication of a misaligned control rod then:

1. Reactor thermal power shall be reduced within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> to less i

than 60% of the allowable power for the reactor coolant pump combination and the Nuclear Overpower Trip Setpointa, based on flux and flux / flow imbalance, shall be reduced within the next 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> to 65.5% of the thermal power value allowable for the reacecr coolant pump cembination.

3.5-8

f. If the maximum positive quadrant power tilt exceeds the Maximum Limit of Table 3.5-1, the reactor shall be shut down within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. Subsequent reactor operation is permitted for the purpose of measurement, testing, and corrective action provided the ther-mal power and the Nuclear Overpower Trip Setpoints allowable for the reactor coolant pump combination are restricted by a reduc-tion of 2% of thermal power for each 1% tilt for the maximum tilt observed prior to shutdown.

g. Quadrant power tilt shall be monitored on a minimum frequency of once every 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> during power operation above 15% full power.

3.5.2.5 Control Rod Positions

a. Technical Specification 3.1.3.5 does not prohibit the exercising of individual safety rods as required by Table 4.1-2 or apply to inoperable safety rod limits in Technical Specification 3.5.2.2.

b. Except for physics tests, operating rod group overlap shall be 25%

5% between two sequential groups. If this limit is exceeded, cor-rective measures shall be taken inmediately to achieve an acceptable overlap. Acceptable overlap shall be attained within two hours or the reactor shall be placed La a hot shutdown condition within an additional 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

c. Position limits are specified for regulating and axial power shap-ing concrol rods. Except for physics tests or exercising control rods, the regulating control rod insertion / withdrawal limits are specified on figures 3.5.2-1A1 and 3.5.2-1A2 (Unit 1); 3.5.2-131, 3.5.2-132 and 3.5.2-133 (Unit 2); 3.5.2-1C1, 3.5.2-1C2 and 3.5.2-IC3 (Unit 3) for four pump operation, and on figures 3.5.2-1A1 and 3.5.2-2A2 (Unit 1); 3.5.3-231, 3.5.2-232 and 3.5.2-233 (Unit 2);

3.5.2-2C1, 3.5. 2-2C2 and 3.5.2-2C3 (Unit 3) for two or three pump operation. Also, excepting physics tests or exercising control l

rods, the axial power shaping control rod insertion / withdrawal limits are specified on figures 3.5.2-4A1, and 3.5.2-4A2 (Unit 1);

3.5.2-481, 3.5.2-4B2, ann 3.5.2-4B3 (Unit 2) ; 3.5.2-4C1, 3.5. 2-

! 4C2, and 3.5.2-4C3 (Unit 3).

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If the control rod position limits are exceeded, corrective measures shall be taken immediately to achieve an acceptable control rod posi-tion. An acceptable control rod position shall then be attained

within two hours. The minimum shutdown margin required by Specifi-i cation 3.5.2.1 shall be maintained at all times.

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3.5-9

3.5.2.6 Xsnan Ranctivity Except for physics tests, reactor power shall not be increased above the power-level-cutoff shown in Figures 3.5.2-1A1, and 3.5.2-1A2 for Unit 1; .?igures 3.5.2-131, 3.5.2-132, and 3.5.2-133 for Unit 2; and Figures 3.5.2-1C1, 3.5.2-1C2, and 3.5.2-1C3 for Uni 3 unless one of the following conditions is satisfied:

1. Xenon reactivity did not deviate more than 10 percent from the equi-librium value for operation at steady state power.

2. Xenon reactivity deviated more than 10 percent but is now within 10 percent of the equilibrium value for operation at steady state rated power and has passed its final maximum or minimum peak during is ap-proach to its equilibrium value for operation at the power level cut-off.

3. Except for xenon free startup (when 2. applies), the reactor has oper-ated within a range of 37 to 92 percent of rated thermal power for a period exceeding 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.

3.5.2.7 Reactor power imbalance shall be monitored o'n a frequency not to exceed two hours during power operation above 40 percent rated power. Except

or physics tests, imbalance shall be maintained within :he envelope de fined by Figures 3.5. 2-3A 1, 3.5. 2-3A2, 3.5. 2-331, 3.5. 2-332, 3.5. 2-333, 3.5.2-3C1, 3.5.2-3C2, and 3.5.2-3C3. If the imbalance is not within the envelope defined by these figures, corrective measures shall be taken to achieve an acceptable imbalance. If an acceptable imbalance is not achieved withic two nours, reactor power shall be reduced until imbalance limits are met:

3.5.2.3 The control rod drive patch panels shall be locked at all :imes with limited access to be authorized by the manager or his designated alternate.

3.5-13

Bases Operation at power with an inoperable control rod is permitted within the limits provided. These limits assure that an acceptable power distribution is maintained and that the potential effects of red misalignment on associ-ated accident analyses are minimized. For a rod declared inoperable due to misalignment, the red with the greatest misalignment shall be evaluated first.

Additionally, the position of the rod declared inoperable due to misalignment shall not be included in computing the average position of the group for deter-mining the operability of rods with lesser misalignments. When a control rod is declared inoperable, boration may be initiated to achieve the existance of 1% ik/k hot shutdown margin.

The power-imbalance envelope defined in Figures 3.5.2-3A1, 3.5.2-331, 3.5.2-3B2, 3.5.2-3B3, 3.5.2-3C1, 3.5 2-3C2 and 3.5.2-3C3 is based on LCCA analyses which have defined the zaximum linear heat rate (see Figure 3.5.2-5) such that the maximum clad temperature will not exceed the Final Acceptance Criteria. Cor-rective measures will be taken immediately should the indicated quadrant tilt, rod position, or imbalance be outside their specified boundary. Cperation in a situation that would cause -he Final Acceptance Cri:eria to be approached should a 10CA occur is highly improbable because all of :te pcwer distribu-tion parameters (quadrant tilt, rod position, and imbalance) must be at their 1 mits while simultaneously all other engineering and uncertainty factors are also at their limits.** Conservatism is introduced by application of:

2. Nuclear uncertainty factors

5. Thermal calibration

c. Fuel densification power spike factors (Units 1 and 2 only) 1

d. Hot rod manufacturing tolersuce factors

e. Fuel rod bowing power spike factors The 25% : 5% overlap between successive control rod groups is allowed since the worth of a rod is lower at the upper and lower part of the stroke. Con-trol rods are 2::anged in groups or banks defined as follows:

Grouc Functica 1 Safety 2 Safety 3 Safety 4 Safety 5 Regula ting 5 Regulating 7 Ienon ::ansient override 3 A?SR (axial power shaping bank) vvActual operating limits depend on vnether or act incore or excore detectors are used and taet: respective instrument calibration errors. The m2 hod used to define the operating limits is defined in plant operating proced' res.

1 3.5-11

Table 4.1-2 MINIMLH EQUIPMENT TEST FRICUENCY Item Test Frequencv

1. Control Rod Movement (I) Movement of Each Rod Monthly l

2. Pressurizer Safety Valves Setpoint 50*. Annu-ally

3. Main Steam Safety Valves Setpoint 25* Annu-ally 4 Refueling System Interlocks Functional Prior to Refueling S. Main Steam Stop Valves (1) Movement of Each Stop Monthly Valve

6. Reactor Coolant System ( ) Evaluate Daily Leakage

7. Condenser Cooling '4ater Functional Annually System Gravity Flow Test

3. High Pressure Service Functional Monthly

'4ater Pumps and Power Supplies

9. Spent Fuel' Cooling System Functional Prior to Refueling

10. High Pressure and low (3) Pressure Injection System and Prior To Testing l

(1) Applicable only when the reactor is critical l

Applicable only when the reactor - olant is above 200 07 and at a steady-

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! (2) i state temperature and pressure.

(3) Operating pumps excluded.

i 4.1-9 I

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