ML20071N296

Application for Amends to Licenses DPR-53 & DPR-69, Incorporating TS 3.9.1, Refueling Operations,Boron Concentration

ML20071N296
Person / Time
Site:	Calvert Cliffs
Issue date:	08/02/1994
From:	Denton R BALTIMORE GAS & ELECTRIC CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20071N301	List: ML20071N296 ML20071N304
References
NUDOCS 9408050188
Download: ML20071N296 (7)

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Bahimore Gas and E:lectric Company Calvert Clijp Nuclear Power Plant Vice President Nuclear I:ncrgy 1630 Calver1 Clif]s Parkway Lusby, Afaryland20657 410 $86 2200 ht.4155 Local 4I0 260.1453 Baltimore August 2,1994 l

U. S. Nuclear Regulatory Commission Washington, DC 20555 ATTENTION:

Document Control Desk SUllJECT:

Calvert Cliffs Nuclear Power Plant Unit Nos.1 & 2; Docket Nos. 50-317 & 50-318 l

License Amendment Request; Clarification of Actions to Restore Refueling l

Shutdown Margin Pursuant to 10 CFR 50.90, the Baltimore Gas and Electric Company hereby requests an Amendment to Operating License Nos. DPR-53 and DPR-69 by the incorp; ration of the changes described below into the l

j Technical Specifications for Calvert Cliffs Unit Nos. I and 2.

DESCRIPTION Technical Specification 3.9.1, " Refueling Operations, Boron Concentration", provides actions to be taken if I

the Reactor Coolant System (RCS) boron concentration falls below its limit. This Action statement needs clarification when the required refueling boron concentration is greater than 2300 ppm. In addition, Technical Specification 3.1.2.7, " Borated Water Sources - Shutdown," could be construed to allow the Mode 6 Refueling Water Tank boron concentration to be less than that required to restore the RCS boron concentration to its limit by the Action statement of Specification 3.9.1. This proposed license amendment will revise the Action of Technical Specification 3.9.1 and the requirements of Technical Specification 3.1.2.7 to clarify the requirements when the required refueling boron concentration is greater than 2300 ppm.

BACKGROUND During refueling operations (e.g., Mode 6), Calvert Clifts Technical Specification 3.9.1, " Refueling Operations - Boron Concentration," requires that the boron concentration of all filled portions of the RCS and the refueling pool be sufficient to maintain ketTS 0.95. The boron concentration necessary to achieve this core reactivity is specified in the Core Operating Limits Report. This amount of shutdown margin is suflicient to ensure that the core will remain suberitical during core alterations and anticipated accidents.

In the event that the boron concentration falls below the required concentration, the Action of j

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Document Control Desk August 2,19')4 l

Page 2 Specification 3.9.1 requires that core alterations or positive reactivity changes be immediately ceased, and j

that boration 2 40 gpm of 2300 ppm boric acid, or its equivalent, be continued until the boron j

concentration is within its limit. (Forty gpm is the flow rate of one charging pump. The 2300 ppm value l

came from an earlier version of the Specification that required that the boron concentration be the greater j

of 2300 ppm or the concentration required to maintain a k grs 0.95.) If the boron concentration limit is i

e greater than 2300 ppm, it is obvious that borating at 2300 ppm will not restore the required concentration.

The operator must interpret the "or its equivalent" phrase in the Action to require boration at a higher concentration in order to restore the required refueling boron concentration.

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Baltimore Gas and Electric Company expects higher capacity factors at Calvert Cliffs in the future, and reload cores may routinely require a shutdown boron' concentration greater than 2300 ppm. Therefore, we propose to revise the Action of Specification 3.9.1 to climinate a specific flow rate and boron concentration and, instead, require immediate boration until the boron concentration is restored within its limit. The j

proposed Action is the same as that in the corresponding Technical Specification in NUREG-1432, Standard Technical Specifications for Combustion Engineering Plants, September 1992.

i Specification 3.1.2.7, " Borated Water Sources - Shutdown," gives the operability requirements for borated water sources including the Refueling Water Tank (RWT), in Modes 5 and 6. It specifies minimum water i

i volume, minimum temperature, and minimum boron concentration. The mini *num boron concentration is given as 2300 ppm. While this minimum value is correct for Mode 5, a larger boron concentration may bc i

necessary in Mode 6. The RWT is the preferred borated water source for restoring the required boron concentration as required by the Action of Specification 3.9.1. Therefore, the RWT boron concentration in i

Mode 6 should at least be that required by Specification 3.9.1. The proposed change will separate the l

boron concentration requirements in Specification 3.1.2.7.

In Mode 5, 2300 ppm will continue to be j

required. In Mode 6, the boron concentration limit for the RWT will be the boron concentration limit given i

in Specification 3.9.1.

i These changes will clarify the actions and requirements on boron concentration when in Mode 6.

R_EOUESTFD CIIANGE Revisc Technical Specifications 3.9.1 and 3.1.2.7 and the BASES to Specification '.l.2.7 as described in Attachments (1) and (2) for Calvert Cliffs Units 1 and 2, respectively, i

i SAFETY ANALYSIS During refueling operations, the reactivity condition of the core is maintained consistent with the initial conditions assumed for the boron dilution event in the accident analysis (Updated Final Safety Analysis Report Section 14.3) and is sufficient to ensure the core remains suberitical during core alterations. The Technical Specifications require that the boron concentration be maintained to ensure a k r5 0.95.

ef Should the refueling boron concentration drop below the Technical Specifications limit, the current Technical Specifications require boration at 2 40 gpm of 2300 ppm borie acid solution, or its equivalent, until the boron concentration is restored to within its limit. liowever, the Technical Specifications also

Document Control Desk August 2,1994 Page 3 allow the refueling boron concentration limit to be greater than 2300 ppm. In that circumstancc, the operator must interpret the "or its equivalent" phrase to require boration at a boron concentration sufficient to restore the RCS boron concentration to within its limit. The proposed change will revise the action to explicitly require the operator to immediately initiate actions to restore the boron concentration to within its limit.

The proposed change has no effect on plant safety. The refueling shutdown margin and the initial conditions of the accident analysis will continue to be met. The specified flow rate and boric acid solution concentration have been removed from the Action. The specific flow rate has been replaced with a requirement to "immediately

. initiate actions to restore the boron concentration to within its limit." This requires that the opciator restore plant conditions to within the Technical Specification limit as quickly as possible. which is more restrictive than the current Action. The concentration of the boric acid solution to be used is dependent on the boron concentration limit given in the COLR, so a specific concentration should not be specified in the Action. The boron dilution analysis does not assume a specific reactivity insertion rate to mitigate the event. Therefore, the proposed change does not change the intent of the current Action statement.

Specification 3.1.2.7 requires a minimum RWT boron concentration of 2300 ppm in Modes 5 and 6. In Mode 5, the borated water source requirements are based on providing sufficient shutdown margin after xenon decay and cooldown from 2000F to 1400F. In Mode 6, the borated water sources are needed to provide reactivity control. As described above, the core reactivity requirements for Mode 6 are given by Specification 3.9.1, so a RWT boron concentration greater than 2300 ppm may be required if the Specification 3.9.1 refueling boron concentration is greater than 2300 ppm. Therefore, we propose to split the boron concentration requirement in Specification 3.1.2.7.

In Mode 5, 2300 ppm will still be the requirement. In Mode 6, the RWT boron concentration limit will be that required by Specification 3.9.1.

This will ensure that the RWT is available as a borated water source in Mode 6 if called upon by the Action of Specification 3.9.1. Note that there is no equivalent specification in NUREG-1432.

The potential increase in boron concentration will not have an adverse effect on the RWT. The maximum boron concentration for the RWT is given in BASES 3/4.1.2 as 2700 ppm. Specification 3.9.1 boron concentration limits are not expected to exceed approximately 2500 ppm and will not exceed 2700 ppm without consideration of the impact on the RWT.

'Ihis change has no impact on plant safety.

Currently, Baltimore Gas and Electric Company administratively requires that the RWT boron concentration be maintained above the limit in Specification 3.9.1. The proposed change, and the revision to the BASES of Specification 3.1.2.7, makes the relationship between Specifications 3.1.2.7 and 3.9.1 in Mode 6 explicit instead ofimplicit.

Document Control Desk August 2,1994 Page 4 DETERMINATION OF SIGNIFICANT IIAZARDS The proposed change has been evaluated against the standards in 10 CFR 50.92 and has been determined to not involve a significant hazards consideration, in that operation of the facility in accordance with the proposed amendments:

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Would not involve a sigmficant increase in the probability or consequences of an accident previously evaluated.

During refueling operations, the reactivity condition of the core is maintained consistent with the initial conditions assumed for the boron dilution event in the accident analysis (Updated Final Safety Analysis Report Section 14.3) and is suf0cient to ensure the core remains suberitical during core alterations. Technical Speci0 cation 3.9.1 requires that the boron concentration be maintained to ensure a k rr 5 0.95. Should the boron concentration drop e

below the Technical Specifications limit, the Action requires horation at a speciDed flow rate and boron concentration until the boron concentration is restored to within its limit. Refueling boron concentrations higher than the concentration specified by the Action in Specification 3.9.1 are allowed by the Technical Specifications and clarification of the Action for that circumstance is needed. The proposed change eliminates the speelned flow rate and boron concentration in the Action and substitutes a directive to immediately initiate action to restore the boron concentration to within its limits. The accident analysis does not assume a specific baration rate, but only assumes that the operator acts to terminate the dilution.

Therefore, the consequences of the event are unchanged. In addition, the proposed change revises the boron concentration limit on the Refueling Water Tank in Mode 6 to make the boron concentration limit on the tank the same as the boron concentration limit on the reactor coolant system. This will ensure that the RWT will contain water of a sufficient boron concentration to respond to a boron dilution event.

The proposed change does not change the boron concentration or shutdown margin required by Specification 3.9.1 and continues to meet the initial conditions of the boron dilution event.

Therefore, the probability of a boron dilution event is not increased. Furthermore, the revised action ensures that the appropriate actions for a boron dilution event will be taken and that a borated water source of sufficient concentration is available to respond to that event. Therefore, the consequences of a boron dilution event are not increased.

Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated 2.

Would not create the possibility of a r-

.np unt type of accident from any accident previously evaluated.

The proposed change does not represent a significant change in the con 0guration or operation of the plant. The proposed actions will result in the same operator actions as the current Technical Specifications. The minimum boron concentration of the Refueling Water Tank in Mode 6 may be increased above the current value, but the concentrations will be within the analyzed maximum concentration for that tank.

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Document Control Desk August 2,1994 Page 5 l

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Therefore, the proposed change does not create the possibility of a new or different type of accident

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l from any accident previously evaluated.

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Would not imvive a significant reduction in a margin ofsafety.

He margin of safety provided by Specification 3.9.1 is to ensure that the core remains suberitical during a boron dilution event and during core alterations. The proposed change does not alter the required shutdown rnargin or significantly change the actions to '., taken if that shutdon margin is lost. The proposed change ensures that all assumed borated water sources will have sufficient l

boron concentration to respond to a boron dilution event.

Therefore, the proposed change does not involve a significant reduction in a margin of safety.

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ENVIRONMENTAI, ASSESSMENT l

The proposed amendment would change requirements with respect to the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 or changes to an inspection or surveillance requirement. We have determined that the proposed amendment involves no significant hazards consideration, and that operation with the proposed amendment would result in no significant change in the types or significant increases in the amounts of any effluents that may be released offsite, and in no significant increase in individual or cumulative occupational radiation exposure. Therefore, the proposed amendment is eligible for categorical exclusion as set forth in 10 CFR 51.22(c)(9) Pursuant to 10 CFR 51.22(b) no emironmental impact statement or environmental assessment is needed in connection with the approval of the proposed amendment.

SCIIEDUI,E This change is requested to be approved and issued by January 3,1994. We desire to clarify these requirements prior to the next refueling outage. liowever, issuance of this amendment is not currently identified as having an impact on outage completion or continued plant operation.

SAFETY COMMITTEE REVIEW These proposed changes to the Technical Specifications and our determination of significant haz rds have been reviewed by our Plant Operations and Safety Review Committee and Offsite Safety Review I

Committee. They have concluded that implementation of these changes will not result in an undue risk to the health and safety of the public.

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Document Control Desk August 2,1994 Page 6 Should y ou have any further questions regarding this matter, we will be pleased to discuss them with you.

Very truly yours, I

STATE OF MARYLAND

TO WIT:

COUNTY OF CALVERT I hereby certify that on the _

day of 61US

, 19 before me, the subscriber, a (k /tfrI Oounh

, personally U

Notary Public of the State of Mary and in and for appeared Robert E. Denton, being duly sworn, and states that he is Vice President of the Iditimore Gas and Electric Company, a corporation of the State of Maryland; that he provides the foregoing response for the purposes theicin set forth; that the statements made are true and correct to the best of his knowledge, information, and belief; and that he was authorized to provide the response on behalf of said Corporation.

WITNESS my Hand and Notaria' Seal:

[

Notary Public My Commission Expires:

doit/

8 Dajd RED /BDM//dtm Attachmente (1)

Unit i Technical Specification Revised Pages (2)

Unit 2 Technical Specification Revised Pages cc:

D. A. Brune, Esquire J. E. Silberg, Esquire M. K. Boyle, NRC D. G. Mcdonald, Jr., NRC T. T. Martin, NRC P. R. Wilson, NRC R. I. McLean, DNR J. II. Walter, PSC