Text

Amends 174 & 151 to Licenses DPR-53 & DPR-69,respectively, Revising TSs Relating to Reactivity Control Systems to Provide Clarification & Simplification for Control Element Assemblies
	ML20127D152
Person / Time
Site:	Calvert Cliffs
Issue date:	09/03/1992
From:	Capra R; Office of Nuclear Reactor Regulation
To:	;
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ML20127D156	List: ML20127D152; ML20127D162;
References
	NUDOCS 9209110222
	Download: ML20127D152 (30)
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8 UNITED STATES g,

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%,,,,,8 BALTIMORE GAS AND ELECTRIC COMPANY DOCKET NO. 50-317 CALVERT CLIFFS N1(1 EAR POWER PLANT UNIT NO. 1 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No.174 License No. DPR-53 1.

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

A.

The application for amendment by Baltimore Gas and Electric Company (the licensee) dated Fetruary 13, 1992, complies with the standards 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 confocmity with the application, the provisions of the Act, and the rules and regulations 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 conducted in compliance with the Commission's regulations; D.

The issuance of this amendment will not be inimicT1 to the common defense and security or to the health and safety of the public; and E.

The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commission's regulations and all applicable requirements have been satisfied.

2.

Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment, and paragraph 2.C.(2) of Facility Operating License No. DPR-53 is hereby amended to read as follows:

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r-c (2) Technical Snecificationi The Technical Specifications contained in Appendices A and B, as revised through Amendment No.174, are hereby incorporated in the license.

The licensee shall operate the facility in accordance with the Technical Specifications.

3.

This license amendment is effective as of the date of its issuance and shall be implemented within 30 days, FOR THE NUCLEAR REGULATORY COMMISSION f Q u. l,

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obert A; pra, Director Project Directorate I-l Division of Reactor Projects - 1/11 Office of Nuclear-Reactor Regulation

Attachment:

Changes to the Technical Specifications Date of Issuance: Septster 3,1992 I'

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UNITED STATES o

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NUCLEAR REGULATORY COMMISSION

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I BALTIMORE GAS AND ELECTRIC _ COMPANY l

DOCKET NO. 50-318 j

CALVERT CLIFFS NUCLEAR POWER PLANT. UNIT NO. 2 f

AMENDMENT TO FACILITY OPERATING llCJNSE j

l Amendment No.151 l

License No. DPR-69 l

l 1.

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

A.

The application for amendment by Baltimore r,as and Electric Company (the licensee) dated February 13, 1992, cc... plies with the standards and requirements of the Atomic Energy Act of 1954, as amer.ded (the Act) and the Commission's rules and regulations set forth in 10 CFR Chapter I; B.

The facility will opcate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C.

There is reasonable as>urance (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 conducted in compliance with the Commission's regulations; D.

The issuance of this 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 amendment is in accordance with 10 CFR Part 51 of the Commission's regulations and all applicable requirements have been satisfied.

2.

Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment, and paragraph 2.C.2 of Facility Operating License No. DPR-69 is hereby amanded to read as follows:

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Technical Specifications The Technical Specifications contained in Appendices A and B, as revised through Amendment No.151, are hereby incorporated in the license.

The licensee shall operate the facility in accordance with the Technical Specifications.

3.

This license amendment is effective as of the date of its issuance and shall be implemented within 30 days.

FOR THE NVCLEAR REGULATORY COMMISSION

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LL' ldo,f cc H bertA apra, Directo

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Projecf irectorate 1-1 Divisi of_ Reactor Projects - 1/11 Office of Nuclear Reactor Regulation

Attachment:

Changes to the Technical Specifications.

Date of Issuance: Septater 3,1992

ATTACHMENT TO LICENSE AMENDMENTS AMENDMENT NO.174 FACILITY OPERATING LICENSE NO. DPR-53 AMENDMENT NO.151 FACILITY OPERATING LICENSE NO. OPR-69 DOCKET NOS. 50-317 AND 50-318 Revise Appendix A as follows:

Remove Paaes Insert Paaes 3/4 1-1 3/4 1-1 3/4 1-4 3/4 1-4 3/4 1-5 3/4 1-5 3/4 1-24 3/4 1-24 3/4 1 3/4 1-25 3/4 1-26 3/4 1-26 3/4 1-27 3/4 1-27 3/4 1-33 3/4 1-33 B3/4 1-1 B3/4 1-1 83/4 1-3 B3/4 1-3 B3/4 1-4 B3/4 1-4 B3/4.1-5 B3/4 1-5 B3/4 1-6 B3/4 1-6 l

l i:

3/4.1 REACTIVITY CONTROL SYSTEMS 3/4.1.1 BORAT10N CONTROL SHUTDOWN MARGIN - T,,, > 200'F LIMITING CONDITION FOR OPERATION 3.1.1.1 The SHUTDOWN MARGIN shall be equal to or greater than the limit line nf Figure 3.1.1-1.

APPLICABILITY:

MODES 1, 2**, 3 and 4.

l ACTION:

With the SHUTDOWN MARGIN less than the limit line of Figure 3.1.1-1*, innediately initiate and continue boration at t 40 gpm of 2300 ppm boric acid solution or equivalent until the required SHUTDOWN MARGIN is restored.

SURVEILLANCE REQUIREMENTS 4.1.1.1.1 The SHUTDOWN MARGIN shall be determined to be equal to or greater than the limit line of Figure 3.1.1-1*:

a.

Within one hour after detection of an inoperable CEA(s) and at least once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months thereafter while the CEA(s) is inoperable.

If the inoperable CEA is untrippable, the above required SHUTDOWN MARGIN shall be increased by an amount at least equal to the withdrawn worth of the untrippable CEA(s).

b.

When in MODES 1 or 2', at least once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months by verifying that CEA group withdrawal is within the Transient Insertion Limits of Specification 3.1.3.6.

l Adherence to Technical Specification 3.1.3.6 as specified in Surveillance Requirement 4.1.1.1.1 assures that there is sufficient l

available SHUTDOWN MARGIN to match the Sil0TDOWN MARGIN requirements l

of the safety analyses.

See Special Test Exception 3.10.1.

I With K,,, t 1.0.

CALVERT CLIFFS - UNIT 1 3/4 1-1 Amendment No. 174

4 3/4.1 REACTIVITY CONTROL SYSTEMS 3/4.1.1 B0 RATION CONTROL SHUTDOWN MARGIN - T,, s; 200*F LIMITING CONDITION FOR OPERATION 3.1.1.2 The SHUTDOWN MARGIN shall be 13.0% Ak/k, and when pressurizer level is less than 90 inches from bottom of the pressurizer, all sources of non-borated water shall be 5 88 gpm.

APPLICABILITY: H0DE 5.

I ACTION:

a.

With the SHUTDOWN HARGIN < 3.0% Ak/k, immediately initiate and continue boration at t 40 gpm of 2300 ppm boric acid solution or equivalent until the required SHUTDOWN HARGIN is restored, b.

With the pressurizer drained to < 90 inches and all sources of l

non-borated water > 88 gpm, immediately suspend all operations involving positive reactivity changes while the SHUTDOWN MARGIN is increased to compensate for the additional sources of non-borated water or reduce the sources of non-borated water to 5 88 gpm.

SURVEILLANCE REQUIREMENTS 4.1.1.2.1 The SHUTDOWN FMRGIN shall be determined to be 13.0% Ak/k:

a.

Within one hour after detection of an inoperable CEA(s) and at least once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months thereafter while the CEA(s) is inoperable.

If the inoperable CEA is untrippable, the above required SHUTDOWN MARGIN shall be increased by an amount at least equal to the withdrawn worth of the untrippable CEA(s).

l 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 concentratica, 2.

CEA position, CALVERT CLIFFS - UNIT 1 3/4 1-4 Amendment No. 174

3/4.1 REACT!YITY CONTROL SYSTEMS 1

SURVEllLANCE REQUIREMENTS (Continued) 3.

Reactor Coolant System average temperature, 4.

Fuel burnup based on gross thermal energy generation, 5.

Xenon concentration, and 6.

Samarium concentration.

4.1.1.2.2 With the pressurizer drained to < 90 inches determine:

I a.

Within one hour and every 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months thereafter that the level in the Reactor Coolant System is above the bottom of the hot leg nozzles, and b.

Within one hour and every 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months thereafter that the sources of non-borated water are < 88 gpm or the SHUTDOWN MARGIN has been increased to compensate for the additional non-borated water sources.

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CALVERT CLIFFS - UNIT 1 3/4 1-5 Amendment No. 174

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3/4.1 REACTIVITY CONTROL SYSTEMS 3/4.1.3 MOVABLE CONTROL ASSEMBLIES Ful? Lenath CEA Position LIMITING CONDITION FOR OPERATION t

3.1.3.1 The CEA Motion Inhibit and all shutdown and regulating CEAs shall be OPERABLE with each CEA of a given group positioned within 7.5 inches (indicated position) of all other CEAs-in its grou?.

APPLICABILITY: MODES 1* and 2*.

ACTION:

a.

With one or more CEAs (regulating or shutdown) inoperable due. to being untrippable, be in at least HOT STANDBY within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months , b.

With the CEA Motion Inhibit inoperable, within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months either:

- 1.. Restore the CEA Motion Inhibit to OPERABLE status, or 2.

Fully withdraw all CEAs in groups 3 and 4 and withdraw the l

I CEAs in group 5 to less than 5% insertion, or 3.

Be-in at least HOT STANDBY.

c.

With one regulating CEA inoperable due.to causes other than

[

addressed by ACTION a, above, and inserted beyond the Long Tenn Steady State Insertion Limits' but within. its above-specified alignment requirements, operation in MODES 1 and-2 may; continue for up to 7 days per occurrence with a total' accumulated time of 5 14 days per calendar year.

d.- With one_ CEA (regulating-or :hutdown) inoperable due to causes l

other than addressed by-ACTION a, above, but within its abov-specified alignment requirements and either fully withdrawn or within the Long Tem Steady State Insertion Limits if'in CEA group 5, operation in MODES 1 and 2 may continue.

See Special.: Test Exceptions 3.10.2 and 3.10.4.

CALVERT CLIFFS - lJNIT 1 3/4 1-24 Amendment No. 174 x -

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3/4.1 REACTIVITY CONTROL SYSTEMS LIMITING CONDITION FOR OPERATION (Continued) e.

With one CEA (reguleting or shutdown) misaligned from any other CEA in its group by less than 15 inches, operation in MODES I and 2 may continue, provided that the misaligned CEA is restored to within its specified alignment requirements within one hour, otherwise implement Action g.

f.

With one CEA (regulating or shutdown) misaligned from any other l

CEA in its group by 15 inches or more, operation in MODES 1 and 2 may continue, provided that the misaligned CEA is restored to within its specified alignment requirements within the time allowance determined by the Better Axial Shape Selection System (BASSS) or, if the BASSS time allowance is unavailable, the time allowance shown in Figure 3.1.3-1, otherwise implement Action 9 l

If Figure 3.1.3-1 is used, the pre-misaligned F' value used to determine the allowable time to realign the CEA from Figure 3.1.3-1 shall be the latest measurement taken within 5 days prior to the CEA misalignment.

If no measurements were taken within 5 days prior to the misalignment, immediately implement Action 9 l

CALVERT CLIFFS - UNIT 1 3/4 1-25 Amendment No. 174

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3/4.1 REACTIVITY CONTROL SJSTEM,5 LIMITING CONDITION FOR OPERATION (Continued) g.

With one CEA (regulating or shutdown) not within its specified alignment requirements at the conclusion of the time allowance pennitted by Actions e, f or h, immediately start to implement the following actions:

1.

If the THERMAL POWER level prior to the misalignment was greater than 50%'of RATED THERMAL POWER, THERMAL POWER shall be reduced to less than the greater of:

a) 50'4 of RATED THERMAL POWER

)

b) 75% of the THERMAL POWER level prior to the misalignment within one hour after exceeding the time allowance pennitted by Actions e, f or h.

2.

If the THERMAL POWER level prior to the misalignment was

-5 50% of RATED THERMAL POWER, maintain THERMAL POWER no higher than-the value prior to the misalignment.

If negative reactivity insertion is required to reduce THERMAL POWER, boration shall be used. Within one hour after i

establishing the' appropriate THERMAL POWER as required above, either:

.1.. Restore the CEA to within its specified alignment I

requirements, or 2._ Declare'the CEA inoperable. After declaring the CEA inoperab'e, POWER OPERATION may continue for.up to 7 days per occurrence with a total accumulated time of 514 days per calendar year provided that withi_n one hour after declaring the CEA inoperable, the remainder of the CEAs in the group o

with the inoperable CEA are aligned to within 7.5 inches of the inoperable CEA while:

a) maintaining the all_owable CEA sequence and insertion limits shown-on Figure 3.1.3-2; for a regulating CEA, and with the THERMAL POWER level restricted pursuant to Specification 3.1.3,6 during subsequent operation, or y

b) maintaining the_ remainder of_the CEAs-_in a shutdown group withdrawn to at least 129 inches.

1 CALVERT CLIFFS - UNIT 1 3/4 1-26 Amendment No. 174

3/4.1 REACTIVITY CONTROL SYSTEMS 4

LIMITING CONDITION FOR OPERATION (Continued) h.

With more than one CEA (regulating or shutdown) misaligned and each misaligned CEA is within 15 inches of any other CEA in its group (indicated position) restore the misaligned CEAs to within their specified alignment requirements within one hour, otherwise immediately declare the misaligned CEAs inoperabie and implement Action i.

If only one CEA (regulating or shutdown) remains misaligned at the end of one hour, implement Action g,

i. With more than one CEA (regulating or shutdown) inoperable tir with more than one CEA (regulating or shutdown) misaligned and any one or more of the misaligned CEAs is 15 inches (indicated position) or more from any other CEA in its group, be in at least NOT STANDBY within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months .

SURVEILLANCE-REQUIREMENTS 4.1.3.1.1 The position of each CEA shall be determined to be within 7.5 inches (indicated position) of all other CEAs in its group at least once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months except during time intervals when the Deviation Circuit and/or CEA Motion Inhibit are inoperable, then verify the individual CEA positions at least once per 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months .

4.1.3.1.2 Each CEA not fully inserted shall be determined to be OPERABLE

- by inserting it at least 7.5 inches at least once per 31 days.

For the purposes of perfont.ing this CEA operability test, if the CEA has an inoperable position indication channel, the alternate indication system (pulse counter or voltage dividing network) will be used to monitor position.

If a direct position indication (full out reed switch or voltage dividing network) cannot be restored within ten minutes from the commencement of CEA motion, or CEA withdrawal exceeds the surveillance testing insertion by > 7.5 inches, the position of the CEA shall be assumed

- to have been > 15 inches from its group at the commencement of CEA motion.

4.1.3.1.3 The CEA Motion-Inhibit shall be demonstrated OPERABLE at least once per 31 days by' a functional test which verifies that the circuit maintains the CEA group overlap and sequencing requirements of

- Specification 3.1.3.6 and that the circuit also prevents any CEA from being misaligned from all other CEAs in its group by more than 7.5 inches (indicated position).

l l

CALVERT CLIFFS - UNIT 1 3/4 1-27 Amendment No. 174 lu.

4 3/4.1 REACTIVITY CONTROL SYSTEMS 3/4.1.3:

MOVABLE-CONTROL ASSEMBLIES Shutdown CEA-Insertion Limit LIMITING CONDITION FOR OPERATION j

3.1.3.5 'All shutdown CEAs-shall be withdrawn to at least 129.0 inches.

APPLICABILITYi MODES I and 2*'.

ACTION: With one or more shutdown CEA(s) withdrawn, except for I

surveillance' testing pursuant to Specification 4.1.3.1.2 to less than

- 129.0 inches, consider the CEA(s) misaligned, and _imediately apply Specification 3.1.3.1; Actions e, f, h, or i as appropriate.

SURVEILLANCE REQUIREMENTS 4.1.3.5 Each shutdown CEA shall be-determined to-be withdrawn to at-least 129.0 inches:

a. - Within 15 minutes prior to withdrawal of any CEAs in regulating groups during an approach to reactor criticality, and b.

At least once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months thereafter.

f.- -

1

. See-Special Test Exception 3.10.2.

- With K,n t 1 0.

- CALVERT: CLIFFS. -UNIT..1 3/4 1-33 Amendment No.-174 e,r tw+-vv www ww,------w,..w-wry.--v.,-o,-

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l 3/4.1 REACTIVITY CONTROL SYSTEMS BASES 3/4.1.1 BORATION CONTROL 3/4.1.1.1 and 3/4.1.1.2 SHUTDOWN MARGIN A sufficient SHUTDOWN MARGIN ensures that 1) the reactor can be made subcritical from all operating conditions, 2) the reactivity transients associated with postulated accident conditions are controllable within acceptable limits, and 3) the reactor will be maintained sufficiently subtritical to preclude inadvertent criticality in the shutdown condition.

The, st limiting SHUTDOWN MARGIN requirement at beginning of cycle is detemined by the requirements of several transients, including Boron Dilution and Steam Line Rupture.

The SHUTDOWN MARGIN requirements for these transients are relatively small and nearly the same.

However, the most limiting SHUTDOWN MARGIN requirement at end of cycle comes from just one transient, the Steam Line Rupture event.

The requirement for this transient at end of cycle is significantly larger than that for any other event at that time in cycle and, also, considerably larger than the most limiting requirement at beginning of cycle.

The variation in the most limiting requirement with time in cycle has been incorporated into Technical Specification 3.1.1.1, in the fom of a specified SHUTDOWN MARGIN value which varies linearly from beginning to end of cycle.

This variation in specified SHUTDOWN MARGIN is conservative relative to the actual variation in the most limiting requirement.

Consequently, adherence to Technical Specification 3.1.1.1 provides assurance that the available SHUTDOWN MARGIN at anytime in cycle will exceed the most limiting SHUTDOWN MARGIN requirement at that time in cycle.

Without the specified SHUTDOWN MARGIN available, imediate boration is required (by Specifications 3/4.1.1.1 or 3/4.1.1.2) that is at least equivalent to boration from the refueling water tank, at its minimum boric acid concentration, via a charging pump, at its minimum flow rate.

For example, lower flow rates with highcr boric acid concentration could also provide the equivalent boration, but should be verified as equivalent prior to use.

In MODE 5, the reactivity transients resulting from ar.y event are minimal and do not vary significantly during the cycle.

Therefore, the specified SHUTDOWN MARGIN in H0DE 5 via Tecnnical Specification 3.1.1.2 has been set equal to a constant value which is determined by the requirement of the most limiting event at any time during the cycle, i.e., Boron Dilution with a

the pressurizer level less than 90 inches and the sources of non-borated water restricted. Consequently, adherence to Technical Specification 3.1.1.2 provides assurance that the available SHUTDOWN MARGIN will exceed the most limiting SHUTDOWN MARGIN requirement at any time in cycle.

3/4.1.1.3 Boron Dilution i

A minimum flow rate of at least 3000 GPM provides adequate mixing, prevents stratification and ensures that reactivity changes will be gradual during boron concentration reductions in the Reactor Coolant System. A CALVERT CLIFFS - UNIT 1 B 3/4 1-1 Amendment No. 174

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3/4.1 REACTIVITY CONTROL SYSTEMS BASES repair or corrective action may be completed without undue risk to overall facility safety from injection system failures during the repair period.

The boration capability of either system is sufficient to provide a SHUTDOWN MARGIN from all-operating conditions of 3.0% ok/k after xenon decay and cooldown to 200 F.

The maximum boration capability requirement occurs at EOL from full power equilibrium xenon conditions and requires boric acid solution from the boric acid tanks, the concentration and vclume of which are met by the range of values given in Specifications 3.1.2.8 and 3.1.2.9, or 55,627 gallons of 2300 ppm borated water from the refueling water tank. However, to be consistent with the ECCS requirements, the RWT is required to have a minimum contained volume of 400,000 gallons during

-MODES 1, 2,.3 and 4.

The maximum boron concentration of the refueling water tank shall be limited to 2700 ppm and the maximum boron concentration of the boric acid storage tanks shall be limited to 8% to preclude the possibility of boron precipitation in the core during long term ECCS cooling.

With the RCS temperature below 200 F, one injection systeni is acceptable without single failure consideration on the basis of the stable reactivity condition of the reactor and the additional restrictions prohibiting CORE ALTERATIONS and positive reactivity change in the event the single injection system becomes inoperable.

The boron capability required below 200 F is based upon providing a 3%

Ak/k SHUTDOWN MARGIN after xenon decay and cooldown from 200 F to 140 F.

This condition requires either boric acid solution from the boric acid tanks, the requirements of which are met by Specification 3.1.2.7, or 9,844 gallons of 2300 ppm borated water from the refueling water tank.

The OPERABILITY of one Boron Injection System during REFUELING ensures that this system is available for reactivity control while in MODE 6.

-3/4.1.3 MOVABLE CONTROL ASSEMBLIES The specifications of this section ensure that (1) acceptable power distribution limits are maintained. (2) the minimum SHUTDOWN MARGIN is maintained, and (3) the potential effects of a CEA ejection accident are limited to acceptab!e levels.

The ACTION statements' which permit limited variations from the basic requirements are accompanied by additional restrictions which ensure that the original criteria are met. A regulating or shutdown CEA is considered to be misaligned if it is more than 7.5 inches from any other CEA in its group, however, a shutdown CEA is also considered to be misaligned if it is withdrawn to less than 129 inches even if it is within 7.5 inches of all other-CEAs in its _ group.

For the purposes of the Technical Specifications, a dual assembly, connected to a single CEA drive mechanism, is considered L

to be a single CEA (e.g., dual shutdown CEAs connected to a single drive l

mechanism).

CALVERT CLIFFS-- UNIT 1 B 3/4 1-3 Amendment No 174

- _=.

4 3/4.1 REACTIVITY CONTROL SYSTEMS BASES The ACTION statements applicable to an untrippable CEA and to a large l

misalignment (215 inches) of two or more CEAs, require a prompt shutdown of the reactor since either of these conditions may be indicative of a possible loss of mechanical functional capability of the CEAs and in the event of an untrippable CEA, the loss of SHUTDOWN MARGIN. A CEA is considered untrippable when it is known that the CEA would not be insertable in response to a Reactor Protection System signal or is known to be ininovable due to excessive friction er mechanical interference.

For small misalignments (< 15 inches) of the CEAs, there is 1) a small degradation in the peaking factors relative to those assumed in generating LCOs and LSSS setpoints for DNBR and linear heat rate, 2) a small effect on the time dependent long tenn power distributions relative to those used in generating LCOs and LSSS setpoints for DNBR and linear heat rate, 3) a small effect on the available SHUTDOWN MARGIN, and 4) a small effect on the ejected CEA worth used in the safety analysis.

Therefore, the ACTION statement associated with the smal'. misalignment of a CEA permits a one hour time interval during which attempts may be made to restore the CEA(s) to within their alignment requirements prior to initiating a reduction in THERMAL POWER. The one hour time limit is sufficient to (1) identify causes of a misaligned CEA, (2) take appropriate corrective action to realign the CEAs and (3) minimize the effects of xenon redistribution.

Overpower M rgin is provided to protect the core in the event of a large misalignment (215 inches) of a single regulating or shutdown CEA.

I However, this misalignment would cause distortion of the core power distribution.

The Reactor Protective System would not detect the degradation in radial peaking factors and since variations in other system parameters (e.g., pressure and coolant temperature) may not be sufficient to cause trips, it is possible that the reactor could be operating with process variables less conservative tnan those assumed in generating LCO and LSSS setpoints.

The ACTION statement associated with a large CEA misalignment requires prompt action to realign the CEA to avoid excessive margin degradation.

If the CEA is not recligned within the given time constraints, ACTION is specified which will preserve margin, including reductions in THERMAL POWER.

For a single CEA misalignment, the time allowance to realign the CEA (Figure 3.1.3-1 or as determined by BASSS) is permitted for the following reasons:

1.

The margin calculations which support the power distribution LCOs for DNBR are based on a steady-state P, as specified in Technical Specification 3.2.3.

2.

When the actual P, is less than the Technical Specification value, additional margin exists.

CALVERT CLIFFS - UNIT 1 B 3/4 1-4 Amendment No. 174

3/4.1 1E. ACTIVITY CONTROL SYSTEMS BASES 3.

This additional margin can be credited to offset the increase in 3-P, with time that will occur following a CEA misalignment due to g

xenon redistribution.

4.

If an P,, measurement has not been taken recently (within 5 days),

a pre-misaligned value of 1.70 is assumed and no time for realignment is permitted.

g The requirement w reduce power level after the time limit of Figure 3.1.3-1 o ^, the timc limit detemtrad by BASSS is reached offsets the conta a g increase in P, that can occur due to xenon redistribution. A power reduction is not required below 50% power. Below 50's power there is sufficient conservatism in the DNB power distribution LCOs to completely offset any, or any additional, xennn redistribution effects.

The ACTION statements applicable to misaligned or inoperable CEAs include requirements to align the OPERABLE CEAs in a given group with the inoperable CfA. Conformance with these alignment requirements brings the core, within a short period of time, to a configuration consistent with that assumed in generating LCO and LSSS setpoints.

However, extendea operation with CEAs significantly inserted in the core may lead to perturbations in 1) local burnup, 2) peaking factors, and 3) available SHUTDOWN MARGIN which are more adverse than the conditions assumed to exist in the safety analyses and LCO and LSSS setpoints determination.

Therefore, tme limits have been imposed on operation with inoperable CEAs to preclude such adverte conditions from developing.

There are five different operating modes for control of CEAs; Off, Manual Individual, Manual Group, Manual Sequential and Automatic. The Manual Sequential mode is applicable to only the regulating CEAs and the Automatic mode is disabled and not used fe both regulating and shutdown CEAs.

CtEMBILITY of the CEA position indicators is required to detemine CEA positions and thereby ensure compliance with the CEA alignment and insertion limits and ensures proper operation of the rod block circuit.

The CEA " Full In" and " Full Out" limits provide an additional independent means for detennining the CEA positions when the CEAs are at either their fully inserted or fully withdrawn positions. Therefore, the OPERABILITY and the AC110N statements applicable to inoperable CEA position indicators permit continued operations when positions of CEAs with inoperable indicators can be verified by the " Full In" or " Full Out" limits.

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

These verification frequencies are adequate for assuring that the applicable LCOs are satisfied.

CALVERT CLIFFS - UNIT 1 B 3/4 1-5 Amendment No. 174

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5. ! _

L /4.1~ REACT 1Y1TY CONTROL SYSHRR 3

+

BASESJ The surveillance requirements affecting CiAs with inoperable position Indication channels allow 10 minutes for testing each affected CEA. This-

-time limit was selected so that.1)- the-time would be long enough for the

required testing. and 2) if all position indication were lost during testing, the time would be short enough to allow a power reduction to 75%-

- of maximum allowable THERML POWER within two-hours from when the testingwas initiated.- The time limit ensures CEA misalignments occurring during _CEA. testing are corrected within the time requirements required by existing specifications.

The maximum CEA drop'. time restriction lis consistent with the assumed CEA drop time used in the safety-analyses. Measurement with; T,, t 515"F end with all reactor coolant-oumps operating ensures that the m,easured drop times will be-representative of insertion times experienced during a e

reactor trip at operating conditions.

The LSSS set 96fnts and the' power distribution LCOs were generated based upon a' core burnup which would be achieved with'the core operating in an essentially unrodded configuration. Therefore, the CEA insertion limit specifications require that during M00ES'1 und 2, the full length CEAs be Lnearly: fully; withdrawn.

The-amount of CEA-insertion-pennitted by the

Steady State? Insertion Limits of Specification 3.1.3.6 willnot have'6 significant effect _upon the unrodded burnup assumption but will still

' provide Lsufficient; reactivity' control. - The Transient Insertion Limits of Specification 3.1.3.6' are provided to ensure that (1) acceptable power

= distribution limits are maintained, (2) the minimam SHUT 00WN MRGIN -is maintained, end (3)-the potential effects af-a CEA ejection accident are limited to ace.eptable levels; however long term operation at these insertica limits could have adverse effects on core power distribution during subsequent operation in an enrodded configuration.

t>,

t f

s 5

CALVERT: CUFFS.- UNIT 1 B 3/4 1-6 Amendment No. 174 l

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3/4.1 REACTIVITY CONTROL SYSTEMS 3/4.1.1 HORATION CONTROL SHUTDOWN MARGIN - T,,, > 200'F LIMITING CONDITION FOR OPERATION 3.1.1.1 The SHUTDOWN MARGIN shall be equal to or greater than the limit line of. Figure 3.1.1-1.

6PPLICABILITD MODES 1, 2**, 3 and 4.

l e

ACTION: With the SHUTDOWN MARGIN less than the iimit line of 9 3.1.1-1*, immediately initl ate and continue boration at t 40 gpm of 1?nm boric acid solution or equivalent until the required SHUTDOWN-

]

- M is restored.

m G LLANCE REQUIREMENTS 4.1 1.1.1 The SHUTDOWN MARGIN shall be determined to be equal to or 4

j '

greater than the limit line of-Figure 3.1.1-1*:

L a.

Within one t our after detection of an inoperable CEA(s) and at least once p r 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months thereafter while the CEA(s) is L

. inoperable.

If the inoperable CEA is-untrippable, the above -

l.-

p' required SHU1 OWN MARGIN shall be increased by an amount at least y

equal.- to the vithdrawn worth of the untrippable:CEA(s).

j b.-.

When in MODES -1 or 2', at least once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months by verifying D

i that CEA group withdrawal is within'the Transient Insertion

(

Limits 'of Specification 3.1.3.6.

l --

g s

Adherence to Technical Specification 3.1.3.6 as specified in s

4 Surveillance Requirement 4.1.1.1.1 assures.that there is sufficient E

available SHUTDOWN MARGIN to match the_ SHUTDOWN MARGIN requirements E,

'of the safety: analyses.

See-Special Test Exception 3.10.1.

With K,n 2 1 0.

[

CALVERT CLIFFS - UNIT 2 3/4 1-1 Amendment No. 151-i.

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1 l

s l

3/4.1 REACTIVITY CONTROL SYSTEMS 3/4.1.1 BORAT10N CONTROL SHUTDOWN MARGIN - T,,, s 200 F LIMITING CONDITION FOR OPERATION 3.1.1.?

The SHUTDOWN HARGIN shall be 13.0% Ak/k, and when pressurizer level is iess than 90 inches from bottom of the pressurizer, all sources of non-borated water shall be 5 88 gpm.

APPLICABILITY:

MODE 5.

I i

ACTION:

I a.

With the SHUTDOWN KARGIN < 3.0% Ak/k, immediately initiate and continue boration at t 40 gpm of 2300 ppm boric acid solution or equivalent until the required SHUTDOWN KARGIN is restored.

b.

With the pressurizer drained to < 90 inches and all sources of

{

non-borated water > 88 gpm, immediately suspend all operations involving positive reactivity changes while the SHUIDOWN HARGIN is increased to compensate for the additional sources of non-borated water or reduce the sources of non-borated water to 5 88 gpm.

I SURVEILLANCE REQUIREMENTS

}

4.1.1.2 1 The SHUTDOWN MARGIN shall be determined to be 13.0% Ak/k:

l

~

a.

Within one hour after detection of an inoperable CEA(s) and at least once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months thereafter while the CEA(s) is inoperable. If the inoperable CEA is untrippable, the above l

required SHUTDOWN MARGIN shall be increased by an amount at least equal to the withdrawn worth of the untrippable CEA(s)

{

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.

CEA position, i

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CALVERT CLIFFS - UNIT 2 3/4 1-4 Amendment No. 151 l

i 3/4.1 REACTIVITY CONTROL SYSTEMS SURVEILLANCE REQUIREMENTS (Continued) 3.

Reactor Coolant System average temperature, 4.

Fuel burnup based on gross thermal energy generation, 5.

Xenon concentration, and 6.

Samarium concentration.

4.1.1.2.2 With the pressurizer drained to < 90 inches determine:

l a.

Within one hour and every 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months thereafter th:t the level in the Reactor Coolant System is above the bottom of the hot leg nozzles, and b.

Within one hour and every 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months thereafter that the sources of non-borated water are < 88 gpm or the SHUTDOWN MARGIN has been increased to compensate for the additional non-borated water sources.

1 CALVERT CLIFFS - UNIT 2 3/4 1-5 Amendment No. 151

o 3/4.1 REACTIVITY CONTROL SYSTEMS 3/4.1.3 MOVABLE CONTROL ASSEMBLIES Full Lenoth CEA Position LD:ITING CONDITION FOR OPERATION 3.1.3.1 The CEA Motion Inhibit and all shutdown and regulating CEAs shall be OPERABLE with each CEA of a given group positioned within 7.5 inches (indicated position) of all other CEAs in its group.

APPLICABILITY: MODES 1* and 2*.

ACTION:

a.

With one or more CEAs (regulating or shutdown) inoperable due to being untrippable, be in at least HOT STANDBY within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months .

b.

With the CEA Motion Inhibit inoperable, within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months either:

1.

Restore the CEA Mction Inhibit to OPERAELE status, or 2.

Fully withdraw all CEAs in groups 3 anu 4 &nd withdraw the l

CEAs in group 5 to less than 5% insertion, or 3.

Be in at least HOT STANDBY.

c.

With one regulating CEA inoperable due to causes other than l

addressed by ACTION a above, and inserted beyond the Long Term Steady State Insertion Limits but within its above specified alignment requirements, operation in MODES I and 2 may continue for up to 7 days per occurrence with a total accumulated time of

< 14 days per calendar year.

d.

With one CEA (regulating or shutdown) inoperable due to causes l

l other than addressed by ACTION a above, but within its above l

specified alignment requirements and either fully withdrawn or L

within the Long Term Steady State Insertion Limits if in CEA L

group 5, operation in MODEI 1.and 2 may continue.

L i

See Special Test Exceptions 3.10.2 and 3.10.4.

CALVERT CLIFFS - UNIT 2 3/44-24 Amendment No. 151

3/4.1 REACTIVITY CONTROL SYSTEMS LIMITING CONDITION FOR OPERATION (Continued) e.

With one CEA (regulating or shutdown) misaligned from any other CEA in its group by less than 15 inches, operation in H0 DES 1 and 2 may continue, provided that the misaligned CEA is restored to within its specified alignment requirements within one hour, otherwise implement Action 9 f.

With one CEA (regulating or shutdown) mi igned from any other l

CEA in its group by 15 inches or more,

..ation in MODES 1 and 2 may continue, provided that the misaligned CEA is restored to within its specified alignment requirements within the time allowance determined by the Better Axial Shape Selection System (BASSS) or, if the BASSS time allowance is unavailable, the time allowance shown in Figure 3.1.3-1, otherwise implement Action 9 l

If Figure 3.1.3-1 is used, the pre-misaligned P, value used to determine the allowable time to realign the CEA from Figure 3.1.3-1 shall be the latest measurement taken within 5 days prior to the CEA misalignment.

If no measurements were taken within 5 days prier to the misalignment, ininediately implement Action g.

CALVERT CLIFFS - UNIT 2 3/4 1-25 Amendment No. 151

^

- " m 3/4.1 REACTIVITY CONTROL SYSTEMS-LIMITING CONDITION FOR OPERATION (Contin rl) g.

With one CEA (regulating or shutdown) not within its specified alignment requirements at the conclusion of the time allowance pemitted by Actions e, f or h, immediately start to implement the following actions:

If the THERMAL POWER level prior to the misalignment was

1..

greater than 50% of RATED THERMAL POWER, THERMAL POWER shall be reduced to less than the greater of:

a) 50% of RATED THERMAL POWER-b) 75% of the THERMAL POWER level prior to the misalignment within one hour after exceeding the time allowance permitted by Actions e, f or h.

2.

If the THERMAL POWER level prior to the misalignment was

$ 50% of RATED THERMAL POWER, maintain THEP"AL POWER no higher than the value prior to the misalignment.

If= negative reactivity insertion is required to reduce THERMAL POWER, boration shall be used. Within one' hour after establishing the appropriate THERMAL POWER as required above, either:

1.

Restore the CEA to within its specified alignment j

' requirements. or 2.

Dechre the CEA inoperable. After declaring the CEA inoperable, POWER OPERATION may continue for up to 7 days-per occurrence with a total-accumulated time of-5 14 days per celendar year provided that within one hour after declaring the CEA inoperable, the remainder-of the CEAs in the group r

- with the inoperable CEA are aligned to withir. 7.5 inches of the' inoperable CEA while:

a) maintaining the allowable CEA sequence and insertion limits shown on Figure 3.1.3-2; for a regulating CEA, and with the THERMAL POWER level restricted pursuant to Specification 3.1.3.6 during subsequent-operation,:or b) maintaining the remainder of the CEAs in a shutdown group withdrawn-to at least 129 inches.

1 CALVERT CtlFFS - UNIT 2 3/4 1-26 Amendment No. 151

3/4.1 REACTIVITY CONTROL SYSTEMS

^

LIMITING CONDITION FOR OPERATION (Continued) h.

With more than one CEA (regulating or shutdown) misaligned and each misaligned CEA is within 15 inches of any other CEA in its group (indicated position) restore the misaligned CEAs to within their specified alignment requirements within one hour, otherwise imediately declare the misaligned CEAc inoperable and implement Action 1.

If only one CEA (regulating or shutdown) remains misaligned at the end of one hour, implement Action 9 1.

With more than one CEA (regulating or shutdown) inoperable or with more than one CEA (regulating or shutdown) misaligned and any one or more of the misaligned CEAs is 15 inches (indicated position) or more from any other CEA in its group, be in at least HOT STANDBY within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months .

SURVEILLANCE REQUIREMENTS 4.1.3.1.1 The position of each CEA shall be determined to be within 7.5 inches (indicated position) of all other CEAs in its group at least once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months except during time intervals when the Deviation Circuit and/or CEA Motion Inhibit are inoperable, then verify the individual CEA positions at least once per 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months .

4.1.3.1.2 Each CEA not fully inserted shall be determined to be OPERABLE by inserting it at least 7.5 inches at least once per 31 days.

For the purposes of performing the CEA operability test, if the CEA has an inoperable position indication channel, the alternate indication system (pulse counter or voltage dividing network) will be used to monitor position.

If a direct position indication (full out reed switch or voltage dividing network) cannot be restored within ten minutes from the commencement of CEA motion, or CEA withdrawal exceeds the surveillance testing insertion by > 7.5 inches, the position of the CEA shall be assumed to have been > 15 inches from its group at the comencement of CEA motion.

4.1.3.1.3 The CEA Motion Inhibit shall be demonstrated OPERABLE at least l

once per 31 days by a functional test which verifies that the circuit l

maintains the CEA group overlap and sequencing requirements of l

Specification 3.1.3.6 and that the circuit also prevents any CEA from being l

misaligned from all other CEAs in its group by more than 7.5 inches (indicated position).

l l

l CALVERT CLIFFS - UNIT 2 3/4 1-27 Amendment No. 151 l

l

3/4.I' REACTIVITY CONTROL SYSTEMS 3/4.1.3

_ MOVABLE CONTROL ASSEMBLIES' Shutdoin CEA Insertion Limit-1

- LIMITING CONDITION-F0R OPERATION 3;1.3.5 ? All shutdown CEAs shall be withdrawn to at least 129.0 inches.

-APPLICABILITY: ' MODES ~1 and 2".

ACTION: With one or more shutdown CEA(s) withdrawn, except for l

surveillance testing pursuant to Specification 4.1.3.1.2, to less than 129.0 inches,- consider the CEA(s) misaligned,'and-immediately apply Specificction 3.1.3.1; Action e, f, h or i, as appropriate.

I SURVEILLANCE REQUIREMENTS 4.1.3.5 'Each. shutdown CEA shall be determined to=be withdrawn to at least 129.0 inches:

-a. -Within 15 minutes prior to withdrawal of.any CEAs in regulating groups during an approach to reactor criticality, and b.

At.least once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months .thereafter.-

m M

See Special Test-Exception 3.10.2.

Wi th K,,, > 1.0.

CALVERT-CLIFFS - UNIT 2 3/4 1-33 Amendment No. 151 A

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s-w~

4 3/4.1 REACTIVITY CONTROL SYSTEMS BASES 3/4.1.1 BORAT10N CONTROL 3/4.1.1.1 and 3/4.1.1.2 SHUTDOWN MARGIN A sufficient SHUTDOWN MARGIN ensures that 1) the reactor can be made subcritical from all operating conditions, 2) the reactivity transients associated with postulated accident conditions are controllable within acceptable limits, and 3) the reactor will be maintained sufficiently subcritical to preclude inadvertent criticality in the shutdown condition.

The most limiting SHUTDOWN MARGIN requirement at beginning of cycle is determined by the requirements of several transients, including Boron Dilution and. Steam Line Rupture.

The SHUTDOWN MARGIN requirements for these transients are relatively small and nearly the same. However, the most limiting SHUTDOWN MARGIN requirement at end of cycle comes from just one transient, the Steam Line Rupture event. The requirement for this transient at end of cycle is significantly larger than that for any other event at that time in cycle and, also, considerably larger than the most limiting requirement at beginning of cycle.

The variation in the most limiting requirement with time in cycle has been incorporated into Technical Specification 3.1.1.1, in the form of a specified SHUTDOWN MARGIN value which varies linearly from beginning to end of cycle.

This variation in specified SHUTDOWN MARGIN is conservative relative to the actual variation in the most limiting requirement.

Consequently, adherence to Technical Specification 3.1.1.1 provides assurance that the available SHUTDOWN MARGIN at any time in cycle will exceed the most limiting SHUTDOWN MARGIN requirement at that time in cycle.

Without the specified SHUTDOWN MARGIN available, immediate boration is required (by Specifications 3/4.1.1.1 or 3/4.1.1.2) that is at least equivalent to boration from the refueling water tank, at its minimum boric acid concentration, via a charging pump, at its minimum flow rate.

For example, lower flow rates with higher boric acid concentrations could also provide the equivalent boration, but should be verified as equivalent prior to use.

In MODE 5 the reactivity transients resulting from any event are minimal and do not vary significantly during the cycle. Therefore, the specified SHUTDOWN MARGIN in MODE 5 via Technical Specification 3.1.1.2 has been set equal to a constant value which is determincd by the requirement of the most limiting event at any time during the cycle, i.e., Boron Oilution with the pressu.izer level less than 90 inches and the sources of non-borated water restricted. Consequently, adherence to Technical Specification 3.1.1.2 provides assurance that the available SHUTDOWN MARGIN will exceed the most limiting SHUTDOWN MARGIN requirement at any time in cycle.

CALVERT CLIFFS - UNIT 2 B 3/4 1-1 Amendment No. 151

['

-3/4.1 REACTIVITY CONTROL SYSTEMS BASES The ACTION statements which permit limited variations from the basic requirements are accompanied by additional restrictions which ensure that the original criteria are met. A regulating or shutdown CEA is considered to be misaligned if it is more than 7.5 inches from any other CEA in its group, however, a shutdown CEA is also considered to be misaligned if it is withdrawn to less than 129 inches even if it is within 7.5 inches of 'all other CEAs in its group.

For the purposes of the Technical Specifications, a dual assembly, connected to a single CEA drive mechanism, is considered to be a single CEA (e.g., dual shutdown CEAs connected to a single drive i

mechanism).

The ACTION statements applicable to an untrippable CEA and to a large j

misalignment (2,15 inches) of two or more CEA3, require a prompt shutdown of the reactor since either of these conditions may be indicative of a possible loss of mechanical functional capability of the CEAs and in the event of an untrippable CEA, the loss of SHUTDOWN MARGIN. A CEA is considered untrippable when it is known that the CEA would not be insertable in response to a Reactor Protection System signal or is known to be imovable due to excessive friction or mechanical interference.

For small misalignments (< 15 inches) of the CEAs, there is 1) a small degradation in the peaking factors relative to ' hose assumed in generating LCOs and LSSS setpoints for DNBR and linear heat rate, 2) a small effect on the time dependent long term power distributions relative to those used in generating LCOs and LSSS setpoints for DNBR and linear heat rate, 3) a small effect on the available SHUTDOWN MARGIN, and 4) a small effect on the ejected CEA worth used in the safety analysis. Therefore, the ACTION statement associsted with the small misalignment of a CEA permits a one hour: time interval during which attempts may be made to restore the CEA(s) to within their alignment requirements prior to inititting a reduction in THCRMAL POWER. The one hour time limit is sufficient to (1) identify -

causes ofca misaligned CEA, (2) take appropriate corrective actica to realign the CEAs and (3) minimize the effects of xenon redistribution.

Overpower margin is provided to protect the core in the event of a large misalignment (t 15 inches) of a single regulating or shutdown CEA.

l However, this misalignment would cause distortion of the core power distribution. The Reactor Protective System would not detect the degradation in radial peaking factors and since variations in other system parameters (e.g.,- pressure and coolant temperature) may-not be sufficient to cause trips,.it is possible that the reactor could be operating with process variables less conservative than those assumed in generating LCO.

and LSSS setpoints. The ACTION statement associated with a large CEA misalignment requires prompt action to realign the CEA to avoid excessive margin degradation.

If the CEA is not realigned within the given time constraints, action is specified which will preserve margin, including reductions in THERMAL POWER.

CALVERT CLIFFS - UNIT 2 B 3/4 1-4 Amendment No. 151

9 3/4.1 REACTIVITY CONTROL SYSTEMS BASES For a single CEA misalignment, the time allowance to realign the CEA (Figure 3.1.3-1 or as determined by BASSS) is permitted for the following reasons:

1.

The margin calculations which support the power distribution LCOs for DNBR are based on a steady-state Fl as specified in the Technical Specification 3.2.3.

2.

When the actual F! is less than the Technical Specification value, additional margin exists.

3.

This additional margin can be credited to offset the increase in F[ with time that will occur following a CEA misalignment due to xenon redistribution.

4.

If an F[ measurement has not been taken recently (within 5 days),

a pre-misaligned value of 1.70 is assumed and no time for realignment is permitted.

- The requirement to reduce power level after the time limit of Figure.3.1.3-1 or the time limit detemined by BASSS is reached offsets the continuing increase in F! that can occur due to xenon redistribution. A power reduction is not_ required below 50% power. Below 50% power there is sufficient conservatism in the DNB power distribution LCOs to completely offset any, or any additional, xenon redistribution effects.

The ACTION statements applicable to misaligned or inoperable CEAs include requirements to align the OPERABLE CEAs in a given group with the inoperable CEA.

Conformance with these alignment requirements brings the core, within a short period of time, to a configuration consistent with that assumed in generating LC0 and LSSS setpoints.

However, extended operation with CEAs significantly inserted in the core may lead to pecturbations in 1) local burnup, 2) peaking factors, and 3) available SHUTDOWN MARGIN which are more adverse than the conditions assumed to exist in the safety analyses and LC0 and LSSS setpoints detemination.

Therefore, time limits have been imposed on operation with inoperable CEAs to preclude such adverse conditions from developing.

There are five different operating modes for control of CEAs; Off, Manual Individual, Manual Group, Manual Sequential and Automatic. The Manual Sequential mode is applicable to only the regulating CEAs and the Automatic mode is disabled and not used for both regulating and shutdown CEAs.

OPERABILITY cf the CEA position indicators is required to determine CEA positions and thereby ensure compliance with_the CEA alignment and insertion limits and ensures proper operation of the rod block circuit.

The CEA ' Full In" and " Full Out" limits provide an additional independert

. means for determining the CEA positions when the CEAs are at either their fully ir.serted or fully withdrawn positions.

Therefore, the OPERABILITY CALVERT CLIFFS - UNIT 2 B 3/4 1-5 Amendment No. 151

3/4.1 REACTIVITY CONTROL SYSTEMS BASES and the ACTION statements applicable to inoperable CEA position indicators permit continued operations when positions of CEAs with inoperable indicators can be verified by the " Full In" or " Full Out" limits.

CEA positions and OPERABILITY of the CEA position indicators are required to be verified on a nomina.1 basis of once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months with more frequent t-rifications required if an automatic monitoring channel is inoperable.

These verification frequencies are adequate for assuring that the applicable LCOs are satisfied.

The surveillance requirements affecting CEAs with inoperable position indication channels allow 10 minutes for testing each affected CEA. This time limit was selected so that 1) the time would be long enough for therequired testing, and 2) if all position indication were lost during testing, the time would be short enough to allow a power reduction to 75%

of maximum allowable THERMAL POWER within two hours from when the testing was initiated. The time limit ensures CEA misalignments occurring during CEA testing are corrected within the time requirements required by existing specifications.

The maximum CEA drop time restriction is consistent with the assumed CEA drop time used in the accident analyses. Measurements with T., > 515 and with all reactor coolant pumps operating ensures that the measu, red drop

, times will be representative of insertion times experienced during a reactor trip at operating conditions.

The LSSS setpoints and the power distribution LCOs were generated based upon a core burnup which would be achieved with the core operating in an essentially unrodded configuration. Therefore, the CEA insertion limit specifications require that during MODES I and 2, the full length CEAs be nearly fully withdrawn. The amount of CEA insertion pennitted by the Steady State. Insertion Limits of Specification 3.1.3.6 will not have a significant effect upon the unrodded burnup assumption but will still provide sufficient reactivity control. The Transient Insertion Limits of Specification 3.1.3.6 are provided to ensure that (1) acceptable power distribution limits are maintained (2) the minimum SHUTDOWN MARGIN is maintained, and (3) the potential effects of a CEA ejection accident are limited to acceptable levels; however, long term operation at these insertion limits could have adverse effects on core power distribution during subsequent operation in an unrodded configuration.

CALVERT CLIFFS - UNIT 2 B 3/4 1-6 Amendment No. 151

ML20127D152

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