Text

Amend 5 to License NPF-87,revising TS for Facility to Increase Required Min Shutdown Margin for Operational Mode 5 for Cycle 2 Operation
	ML20085M820
Person / Time
Site:	Comanche Peak
Issue date:	10/18/1991
From:	Black S; Office of Nuclear Reactor Regulation
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TEXAS UTILITIES ELECTRIC COMPANY, ET AL.*

COMANCHE PEAK STEAM ELECTRIC STATION, UNIT 1 DOCKET NO. 50-445 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 5 License No. NPF-87 1.

The Nuclear Regulatory Commission (the Commission) has found that:

A.

The applicat*7n for amendment by Texas Utilities Electric Company (TV Electric. acting for itself and as agent for Texas Municipal Power Agency (licerisees) dated August 9,1991, complies with the str'dards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commission's rules and regulations set forth in 10 CFR Chapter I; B.

The facility will operate in conformity with the apolication, as amended, the provisions of the Act, and the rules rod regulations L

of the Commission; C.

There is reasonable assurance:

(i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be col.ucted in compliance with the Commission't regulations; D.

The issuance of this license amendment will not be inimical to the common defense and security or to the health and safety of the public; and E.

The issuance of this ame.'- nt is ?q accordance with 10 CFR Part 51 of the Commission's rege 'acion, ar.: all applicable requirements have been satisfied.

The curre7t owners of the Comanche Peak Steam Electric Station are:

Texas Utilities Electric Company and Texas Municipal Power Agency.

Transfer of ownership from Texas Municipal Power Agency to Texas Utilities Electric Company was previously authorized by Amendment Nc. 9 to Construction Permit CPPR-126 on August 25, 1988 to take place in 10 installments as set forth in the Agreement attached to the application for Amendment dated March 4, 1988.

At the completion thereof, Texas Municipal Power Agency will no longer retain any ownership interest.

J 9111120243 911018 PDR ADOCK OU

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2.

Accordingly, the license is amended by changes to the Technical Specifi-cations Ts indicated in the attachment to this license amendment and Paragraph 2.C.(2) of Facility Operating License No. NPF-87 is hereby amended to read as follows:

2.

Technical Specifications The Technical Specifications contained in Appendix A, as e~ sited through Amendment No.

5, and the Environmental Protec % Plan 9

contained in Appendix B, both of which are attached hereto, are hereby incorporated in the license.

The licensee shall operate the facility in accordance with-the Technical Specifications and the Environmental Protection Plan.

3.

The license amendment is effective as of its date of issuance to be implemented within 30 days of issuance.

FOR THE NUCLEAR REGULATORY COMMASSION 3

Suzann ek, Director Project Directorate IV-2 Division of Reactor Projects _- III/IV/V Office of Nuclear Reactor Regulation

Attachment:

Changes to the Technichi Specifications Date of Issuance:

October 18, 1991 i

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ATTACHMENT TO LICEN5_E,r;ENDMENT NO. 5 1

4 rACILITY OPERATING LICENSE NO. NPF 87 DOCKET NO. 50 445 Revise Appendix A Technical Specifications by removing the pages identified below and inserting the enclosed pages.

The revised pages are identified by amendment number and contain marginal lines indicating the area of change.

The corresponding overleaf pages are also provided to maintain document completeness.

REMOVE INSERT 3/4 1-3 3/4 1-3 3/4 1-8 3/4 1-8 b

3/4 1-10 3/4 1-10 3/A 1-12 3/4 1-12 B 3/4 1-1 B 3/4 1-1 B 3/4 1-3 B 3/4 1-3 1

h ATTACHMENT TO LICENS2 AMENDMENT,NO. 5 FACILITY OPERATING LICENSE NO. NPF-87 DOCKET N3.50-44J Revise Appendix A Technical Specifications by removing the pages identified below and inserting the enclosed pages.

The revised pages are identified by amendment number and contain marginal lines indicating the area of change.

The corresponding overleaf pages are also provided to maintain document completeness.

REMOV_E INSERT 3/4 1-3 3/4 1-3 3/4 1-8 3/41-8 3/4 1-10 3/4 1-10 3/4 1-12 3/4 1-12 B 3/4 1-1 B 3/4 1-1 B 3/4 1-3 B 3/4 1 3 i

REACTIVITY CONTROL SYSTEMS l'

e SHUTDOWN MARGIN - T LESS THAN OR EQUAL TO 200 F avg LIMITING CONDITION FOR OPERATION 3.1.1. 2 The SHUTDOWN MAR 3IN shall be greater than or equal to 1.3% Ak/k.

APPLICABILITY:

MODE 5.

ACTION:

With the SHUTDOWN MARGIN less than 1.3% Ak/k, immediately initiate and continue boration at greater than or equal to 30 gpm of a solution containing greater than or equal to 7,000 ppin boron or equivalent until the required SHUTDOWN MARGIN is restored.

SURVEILLANCE REQUIREMENTS 4.1.1.2 The SHUTOOWN MARGIN shall be determined to be greater than or equal i

to 1.3% Ak/k:

Within 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months after detection of an inoperable control rod (s) and a.

at least once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months thereafter while the tod(s) is inoperable.

If the inoperable cntrol rod is immovable or untrippable, the SHUTDOWN MARGIN shall be verified acceptable with an increased allowance for the withdrawn worth of the immovable or unteippable contrcl rod (s); and e

b.

At least once per 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months by consideration of the following factors:

1)

Reactor Coolant System boron concentration, 2)

Control rod position, 3)

Reactor Coolant System average temperature,-

1)

Fuel burnup based on gross thermal energy generation, 5)

Xenon concentration, and 6)

Samarium concentration.

s COMANCHE PEAK - UNIT 1 3/4 1-3 Amendment No.

5

m-REACTIVITY CONTROL SYSTEMS MODERATOR TEMPERATURE COEFFICIENT i

LIMITING CONDITION FOR OPERATION

~

3.1.1.3 The t.oderator temperature coefficient (MTC) shall be:

Less positive than 0 ak/k/*F for the all rods withdrawn, beginning a.

~

of cycle life (BOL),-hot zero THERMAL POWER condition; and b.

Less negative than -4.0 x 10 4 Ak/k/*F - for the all rods withdrawn, end of cycle life (EOL), RATED THERMAL POWER condition.

APPLICABILITY:

Specification 3.1.1.3a. - MODES I and 2* only**.

Specification 3.1.1.3b. - MODES 1, 2, and 3 only**.

ACTION:

With the MTC more positive than the limit of Specification 3.1.1.3a.

a.

above, operation in MODES 1 and 2 may proceed provided:

1.

Control rod withdrawal limits are established and maintained sufficient to restore the MTC to.less oositive than 0 ak/k/*F within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months or be in HOT STANDBY within the next 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months .

These withdrawal limits shall be in addition to the insertion limits of Specification 3.1.3.6; 2.

The control rods are maintained within the withdrawal limits established above until a subsequent calculation verifies that

.the MTC has been restored to within its limit for the all rods withdrawn condition; and 3.

A Special Report is prepared and submitted to the Commission, pursuant to Specification 6.9.2,' within 10 days, describing the value of the measured MTC, the interim control rod withdrava1 limits, and the predicted avecage core burnup necessary for restoring the lositive MTC to within its limit for the all rods withdrawn condition.

b.

With the MTC more negative than the limit of Specification 3.1.1.3b.

above, be in HOT SHUTDOWN within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months .

i

With K,ff greater than or emial to 1

- see Special Test Exceptions Specification 3.10.3.

COMANCHE PEAK - UNIT 1 3/4 1-4 r

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REACTIVITY CONTROL SYSTEMS 4

3/4.1.2 BORATION SYSTEMS FLOW PATH - SHUTDOWN LIMITING CONDITION FOR OPERATION 3.1.2.1 As a minimum,~one of the following boron injection flow paths sball l j be OPERABLE and capable of being powered from an OPERABLE emergency power source:

a.

A flow path from the boric acid storage tanks via either a boric acid transfer pump or a gravity feed connection and a charging pump to the e

Reactor Coolant System if the boric acid storage tank in Specification 3.1.2.5a. is OPERABLE, or b.

The flow path from the refueling water storage tank via a centrifugal charging pump to the Rea: tor Coolant System if the refueling water storage tank in Specification 3.1.2.5b. is OPERABLE.

APPLICABILITY:

MODES 5 and G.

ACTION:

With none of the above flow' paths OPERABLE or capable of being powered from an OPERABLE emergency power source, suspend'all operations involving CORE ALTERATIONS or positive reactivity changes.

SURVEILLANCE REQUIREMENTS 4.1.2.1 At least cne of tue above required flow-paths ;5all be demonstrated OPERABLE:

a.

At least once per 7 days by verifying that the temperature of the flow path is greater than or equal to 65'r when a flow path from the boric acid storage tanks is used, and b.

At least once per 31 days by verifying that each valve (manual, power-operated, or automatic) in the flow path that is not locked, sealed, or otherwise secured.in position, is in its correct position.-

COMANCHE PEAK - UNIT 1 3/4 1-7

REACTIVITY CONTROL SYSTEMS FLOW PATHS - OPERATING LIMITING CONDITION FOR OPERATION 3.1.2.2 At least wo of the following three boron injection flow paths shall be OPERABLE:

a.

The flow path from the boric acid storage tanks via either a boric acid transfer pump or a gravity feed connection and a charging,nua.p to the Reactor Coolant System (RCS), and b.

Two flow paths from the refueling water storage tank via centrifugal charging pumps to the RCS.

APPLICATION:

MODES 1, 2, 3, and 4.*

ACTION:

With only one of the above,equired boron injection flow paths to the RCS OPERABLE, restore at least two boron injection flow paths to the RCS to GPERABLE status within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months or be in at least HOT STANDBY and borated to a SHUTDOWN MARGIN equivalent to at least 1.3% ak/k at 200 F within the next 6 hour6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months s: restore at least two flow paths to OPERABLE status within the next 7 days or be in COLD SHUTJ0WN within the next 30 hours3.472222e-4 days 0.00833 hours 4.960317e-5 weeks 1.1415e-5 months .

SURVEILLANCE REQUIREMENis 4.1.2.2 At least two of the above required flow paths shall be demonstrated OPERABt.E:

At least once per 7 days by verifying that the temperature of the a.

flow path from the boric acid storage tanks is greater than or equal to 65 F when it is a required water source; b.

At least once per 31 days by verifying that each valve (manual, power-operated, or automatic) in the flow path that is not locked, sealed, or otherwise secured in position, is in its correct position; and At least once per 18 months by veritying that the flow path required c.

by Specification 3.1.2.2a. delivers at least 30 gpm-to the RCS.

"A maximum of two charging pumps shall be OPERABLE whenever the temperature of one or more of the RCS cold legs is less than or equal to 350*F except when Specification 3.4.8.3 is not applicable.

An inoperable pur.p may be energized for testing provided the discharge of the pump has bacq % olated from the RCS by a closed isolation valva (c) with power removed fuo it.e valve operator (s) or by a manual isolation valve (s) securea in the cica,J position.

4 -

COMANCHE PEAK - UNIT 1 3/4 1-8 Amendmant No. 5

R_E_ ACTIVITY CONTROL SYSTEMS E

CHARGING PUMP - SHUTDOWN LIMITING CONDITION FOR OPERATION 3.1.2.3 At least one charging pump in the boron injection flow path required by Specification 3.1.2.1 shall be OPERABLE and capable of being powered from an OPERABLE emergency power source.

APPLICABILITY: MODES 5 and 6.

ACTION:

With no charging pump OPERABLE or capable of being powered from an OPERABLE emergency power source, suspend all operations involving CORE ALTERATIONS or positive reactivity changes.

SURVEILLANCE REQUIREMENTS 4.1.2.3.1 At least once per 92 days the above required positive displacement charging pump shall be demonstrated OPERABLE by verifying that the flow path regt. ired by Specification 3.1.2.la is capable nf delivering at least 30 gpm to the RCS; or 4.1.2.3.2 The above required centrifagal charging cumo shall be cemonstrated OPERABLE by verifying, on recirculation flow, that a differential pressure across the pump of greater than or equal to 2370 psid is developed when tested pursuant to Specification 4.0.5.

4.1.2.3.3 A maximum of two charging pumps shall be GPERABLE, ane charging pump shall be demonstrated inoperable

at least once per 31 days, except when the reactor vessel head is removed, by verifying that the W.or circuit breakers are secured in the open position.

.[

An inoperable pump may be energized for testing provided the discharge of the pump has been isolated from the RCS by a closed isolation valve (s) with power removed from the valva operator (s) or by a manual isolation valve (s) secured in the closed position.

COMANCHE PEAK ' UNIT 1 3/4 1-9 j

REACTIVITY CONTROL SYSTEMS CHARGING PUMPS - OPERATING LIMITING CONDITION FOR OPERATION 3.1.2.4 At least two centrifugal charging pumps shall be OF ERABLE.

APPLICABILITY:

MODES 1, 2, 3*, and 4** *.

ACTION:

With only one charging pump OPERABLE, restore at least two charging pumps to OPERABLE statas within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months or be in at least HOT STANDBY and borated to a SHUTDOWN MARGIN equivalent to at least 1.3% Ak/k at 200*F within the next l

6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months ; restore at least two charging pumps to OPERABLE status within the next 7 days or be in COLD SHUTDOWN within the next 30 hours3.472222e-4 days 0.00833 hours 4.960317e-5 weeks 1.1415e-5 months .

SURVEILLANCE REQUIREMENTS 4.1.2.4.1 The required centrifugal charging pump (s) shall be demonstrated OPERABLE by testing pursuant to Specification 4.0.5.

4.1.2.4.2 The required positive displacement charging pump shall be demonstrated OPERABLE by testing pursuant to Specification 4.1.2.2.c.

4.1 2.4.3 Whenever the temperature of one or more af the Reactor Coolant System (RCS) cold legs is less than cr equal to 350 F, a maximum of two charging pumps shall be OPERABLE, except when Specification 3.4.8.3 is not applicable.

When required, one charging pump shall be demonstrated inoperable # at least y

once per 31 days by verifying that the motor circuit breakers are secured in the open position.

The provisions of Specifications 3.0.4 and 4.0.4 are not applicable for entry into MODES 3 and 4 for the charging pump declared inoperable pursuant to Specification 3.1.2.4 provided the chargir,g pump is restored to OPERABLE status within 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months after entering MODE 3 or prior to the temperature of one or more of the RCS cold itgs exceeding 375*F, whichever comes first.

- In MODE 4 the positive displacement pump may be used in lieu of one of the required centrifupal charging pumps.

n inoperable pump may be energized for testing provided the discharge of A

n the pump has been isolated from the RCS by a closed isolation valve (s) with power removed from the valve operator (s) or Ly a manual isolation valve (s) secured in the closed p)sition.

COMANCHE PEAK - UNIT 1 3/4 1-10 Amendment No. 5

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REACTIVITY CONTROL SYSTEMS BORATE 0 WATER SOURCE - SHUTD0'..c 1.IMITINGCONDITIONFOROPERATION 3.1.2.5 As a minimum, one of the following borated water sources shall be OPERABLE:

a.

A boric acid storage tank with:

1)

A minimum indicated borated water level of 10% when using the boric acid transfer pump, 2)

A minimum indicated borated water level of 20% when using the gravity feed connection, 3)

A minimum boron concentration of 7000 ppm, and 4)

A minimum solution temperature of 65*F.

a b.

The refueling water storage tank (RWST) with:

1)

A minimum indicated borated water level of 24%,

2)

A minimum boron concentration of 2000 ppm, and 3)

A minimum solution temperature of 40*F.

APPLICABILITY:

MODES 5 and 6.

ACTION:

Wit'n no borated water source OPERABLE, suspend-all cperations involving CORE ALTfRATIONS or positive reactivity changes.

4 SURVEILLANCE REQUIREMENTS 4.1.2.5 The above required borated water sw ice shall be demonstrated OPERABLE:

a.

At least once per 7 days by:

1)

Verifying the boron concentration of.the _ water, o

2)

Verifying"the indicated borated water level, and 3)

Verifying the boric acid storage tank solution temperature when it is the source of borated water, b.

At least once per 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months by verifying the RWST temperature when it is the source of borated water and the outside air temperature is less than 40*F.

COMANCHE PEAK - UNIT 1 3/4 1-11

REACTIVITY CONTROL SYSTEMS B0 RATED WATER SOURCES - OPERATING LIMITING CONDITION FOR OPERATION 3.1.2.6 Asaminimum,thefollowingboratedwatersource(s)shallbdOPERABLE as' required by Specification 3.1.2.2:

a.

A boric acid storage tank with:

1)

A minimum indicated borated water level of 50%,

2)

A minimum boron concentration of 7000 ppm, and 3)

A minimum solution temperature of 65 F.

b.

The refueling water storage tank (RWST) with:

1)

A minimum indicated borated water level of 95%,

2)

A boron concentration between 2000 ppm and 2200 ppm, 3)

A minimum solution temperature of 40 F, and 4)

A maximum solution temperature of 120 F.

APPLICASILITY:

MODES 1, 2, 3, and 4.

ACTION:

With the Soric acid storage tank inoperable and being used as one a.

of the above required borated water sources, restore the tank _to OPERABLE status within 72-hours or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and borated to a SHUTDOWN MARGIN equivalent to at least 1.3% Ak/k at' 200 F; restore the boric acid storage tank to OPERABLE status within the next 7 days or be in COLD SHUTDOWN within the next 30 hcurs.

b.

With the RWST inoperable, restore the tank to OPERABLE status within 1 hours1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months or ba in at least HOT STANDBY within the next 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and in COLD SHUTOOWN within the following 30 hours3.472222e-4 days 0.00833 hours 4.960317e-5 weeks 1.1415e-5 months .

COMANCHE PEAK - UNIT 1 3/4 1-12 Amendment No. 5

3/4.1 REACTIVITY CONTROL SYSTEMS J

BASES 3/4.1.1 B0 RATION CONTROL 3/4.1.1.1 and 3/4.1.1.2 SHUTDOWN MARGIN A sufficient SHUIDOWN MARGIN ensures that:

(1) the reactor can be made subtritical from all operating conditions, (2) the reactivity transients associated with postulated accident conditions are controllable within accepta'le limits, and (3) the reactor will De maintained sufficiently subcritical to precit de inadvertent criticality in the shutdown condition.

SHUTDOWN MARGIN requirements vary throughout core life as a function nf fuel depletion, RCS bo on concentration, and RCS T,yg.

The most restrictive candition occurs at EOL, with f,yg at no loading operating temperature, and is associated with a postulated steam line break accident and resulting uncon-trolled RCS cooldown.

In the analysis of this. accident, a minimum SHVlDOWN MARGIN of 1.6% Ak/k is required to control the reactivity transient Accordingly, the SHUTDOWN MARGIN requirement is based upon this lim l ting condition and is consistent with FSAR safety _ analysis assumptions.

With T,yg less than 200 F, a SHUTDOWN MARGIN of 1.3% Ak/k provides adequate protection and is based on the reselts of the boron dilution accident analysis.

Since the actual overa?1 core reactivity balance mparison required by 4.1.1.1.2 cannot be performed until after criticality is attained, this comparison is not required (tnd tha provisions of Specification 4.0.4 are not applicable) for entry into any Operational Mode within the first 31 EFP0 following initial fuel ioad or refueling.

3/4.1.1.3 MODERATOR TEMPERATURE COEFFICIEhi The limitations on moderator temperature coefficient (MTC) are provided to ensure that the value of this coefficient remains within the limiting condition assumed in the TSAP. accident and transient analyses.

The +RC values of this specification are applicable to a specific set of plant conditions; accordingly, verification of MTC values at conditions other than those explicitly stated will require extrapolation to those conditions in order to permit an accurate comparison.

The most negative MTC value equivalent to the most positive moderator density coef ficient (MDC) was obtained by incrementally correcting the MDC used in the FSAR analyses to nominal operating conditions.

These corrections i

i COMANCHE PEAK - IINIT 1 B 3/4 1-1 Amendment No. 5 7

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RCACTIVITY CONTROL SYSTEMS i,

BASES l

MODERATOR TEMPERATURE COEFFICIENT (Continued) invo~1ved subtracting the incremental change in the MDC associated with a core condition of all Pods inserted (most positive MDC) to an all rods withdrawn condition and, a conversion for the rate of change of moderator density with temperature at RATED THERMAL POWER conditions.

This value of the MDC was then transformed into the limiting MTC value -4.0 x 10 4 ok/k/*F.

The MTC value of -3.1 x 10 4 Ak/':/*F represents a conservative value (with corrections for burnup and soluble boron) at a core condition of 300 ppm equilibrium boron concentt etion.'ind is obtained by making these corrections to the limiting MTC l

value of -4.0 x 10 4 Ak/k/*F.

l l

The Surveillance Requirements for measurement of the MTC at the beginning l

and near the end of the fuel cycle are adequate to confirm that the MTC remains l

within its limits since this coefficient changes slowly due principally to the reduction in RCS boror concentration associated with fuel burnup.

l 3/4.1.1.4 MINIMUM TEMPERATURE FOR CRITICALITY (his speci'ication ensures that the reactor will not be made critical with the Reacts laat System average temperature less than 551*F.

This limitation is req.

ad to ensure:

(1) the moderator temperature coefficient i

is within it analyn d temperature range, (2) the trip instrumentation is within its normal operating range, (3) the pressurizer is capable of being in an OPERABLE status with a steam bubble, and (4) the reactor vessel is above i u minimum RTNDT temperature.

I 3/4.1.2 B0 RATION SYSTEMS The Boron Injection System ensures that negative reactivity control is available during each mode of facility operation.

The components required to perform this function include:

(1) borated water sources, (2) charging pumps, (3) separate flow paths, (4) boric acid transfer pumps, and (5) an emergency power supply from OPERA 3LE diesel gener ors.

With the RCS average temperature above 200*F, a minimum of two boron injection flow paths are required to ensure single functional capability 4 the event an assumed failure renders one of the flow paths inoperable.

The boration capability of either flow path is sufficient to provide a SHUTDOWN MARGIN from expected operating conditions of 1.6% Ak/k efter xenon decay and cooldown to 200 F.

The maximum expected boration capability requirement cccurs at EOL from full power equilibrium xenon conditions and requirer 15,700 gallons of 7000 ppm borated water from the beric acid storage tanks or 70,702 p!1ons of 2000 ppm borated water from the refueling water storage tank O WST).

COMANCHE' PEAK - UNIT 1 B 3/4 1-2

~

I REACTIVITY CONTROL SYSTEMS BASES B0 RATION SYSTEMS (Continued)

With the RCS temperature below 200 F, one Boron Injection System is ac'eptable without single failure consideration on the basis of the stable c

reactivity condition of the reactor and the additional restrictions prohibiting CORE ALTERATIONS and positive reactivity changes in the event the single Boron Injection System becomes inoperable.

The limitation for a maximum of two charging pumps to be OPERABLE and the requirement to verify one charging pump to be inoperable below 350 F provides assurance that a mass addition pressure transient can be relieved by the operation of a single PORV.

The limitation for minimum solution temperature of the borated water sources are sufficient to prevent boric acid crystallization with the highest allowable boron concentration.

The boron capability required below 200*F is sufficient to provide a SHUTDOWN MARGIN of 1.3% ak/k after xenon decay and cooldown from 200*F to 140 F.

This condition requires either 1,100 gallons of 7000 ppm borated water from the boric acid storage tanks or 7,113 gallons of 2000 ppm borated water from the FWST.

l As listed below, the required indicated levels for the boric acid storage tanks and the RWST include allowances for required / analytical volume, unusable volume, measurement uncertainties (which include instrument error and tank tolerances, as applicable), system configuration requirements, and other required volume.

Tank MODES Ind.

Unusable Required Measurement System Other Level Volume Volume Uncertainty Config.

(gal)

RWST 5,6 24%

45,494 7,113 4% of span 57,857 N/A 1,2,3,4 95%

45,494 70,702 4% of span N/A 357,535*

Boric 5,6 10%

3,221 1,100 6% of span N/A N/A Acid 5,6 20%

3,221 1,100 6% of span 3,679 N/A Storage (gravity feed)

Tank 1,2,3,4 50%

3,221-15,700 6% of span N/A N/A The OPERABILITY of one Boron Injection System during REFUELING ensures that this system is available for reactivity control while in MODE 6.

l

Additional volume required to meet Specification 0.5.4.

l COMANCHE PEAK - bNIT 1 B 3/4 1-3 Amendment No.

5

REACTIVITY CONTROL SYSTEMS

^

4 BASES

.e 3/4.1.3 MOVABLE CONTROL ASSEMBLIES The specificaticns of this section ensure that:

(1) acceptable power distri-bution limits are maintained, (2) the minimum SHUTDOWN MARGIN is maintained, and (3) the potential effects of rod misalignment on associated accident analyses are limited.

OPERABILITY of the control rod position indicators is required to.

determine control rod positions and thdreby 1.asure compliance with the control rod alignment c.nd insertion limits.

Verification that the Digital Rod Position p

Indicator agrees with the demanded position within i 12 steps at 24, 48, 120, f

and 228 steps withdrawn for the Control Banks and 18, 210, and 228 steps with-drawn for the Shutdown Banks provides assurances that the Digital Rod Position Indicator is operating correctly over the full range of indication.

Since the Digital Rod Position Indication System does not indicate the actual shutdown rod position between 18 steps ar.d 210 steps, only points in the indicated rar.gss.

are picked for verification of agreement with demandea position.

The ACTION statements which permit limited variations from the basic requirements are accompanied by additional restrictions which ensure that the original design criteria are met. Misalignment of a rod requires aeasurement of peaking factors and a restriction in THERiiAL POWER.

These ru crictions pro-vide assurance of fuel rod integrity during continued operation.

In aduition, those safety analyses affected by. misaligned rod are reevaluated to confirm that the results remain valid during future operation.

For Specification 3.1.3.1 ACTIONS b and e it is incumbent upon the plant to verify tne trippability of the inoperable control red (s).

This may be by verification of a control system failure, usually electrical in nature, or-(

that the failure is associatad with the control rod stepping cechanism.

In 1

the event the plant is unable to varify the rod (s) trippability, it must be assumed to be untrippable and thus fall under the requirements of ACTION a.

Assuming a controlled shutdown from 100% RATED THERMAL POWER, this allows approximately four hoers for this verification.

The maximum rod drop time restriction is consistent with the assumed rod drop time used in the safety analyses. Heasurement with T,yg greater than or equal to 551*F and with all reactor coolant pumps operating ensures that the measured drop times will be representative-of insertion times experienced during a Reactor trip at operating conditions.

Control rod positions and OPERABILITY-of the rod position-indicators are required to be verified en a nominal basis of once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months with more fre-quent verifications required if an automatic monitoring channel is inoperable.

These verification frequencies are adeoutta for assuring thr.t the applicable LCOs are satisfied.

COMANCHE PEAK - UNIT 1 B 3/4 1-4

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ML20085M820

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