ML20059H827

Application for Amend to License DPR-69 by Incorporating Changes to Extend Use of Current Heatup & Cooldown Curves to Allow Operation Beyond 12 EFPY

ML20059H827
Person / Time
Site:	Calvert Cliffs
Issue date:	11/01/1993
From:	Denton R BALTIMORE GAS & ELECTRIC CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20059H829	List: ML20059H827 ML20059H835
References
NUDOCS 9311100237
Download: ML20059H827 (5)

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l' BALTIMORE GAS AND ELECTRIC 1650 CALVERT CLIFFS PARKWAY . LUSBY, MARYLAND 20657-4702 RoetstT E. DcNTON vect PRtstoENT NUCLEAR rNERGY (4to) ireo-4 4 BS  !

November 1,1993 1 U. S. Nuclear Regulatory Commission Washington,DC 20555 A1TENTION: Document Control Desk

SUBJECT:

Calvert Cliffs Nuclear Power Plant Unit No. 2; Docket No. 50-318 License Amendment Request; Extension of Unit 2 Heatup and Cooldown Curves

REFERENCES:

(a) Ixtter from Mr. R. E Denton (BG&E) to NRC Document Control Desk (NRC), dated February 16, 1993, Response to Request for AdditionalInformation Regarding Response to the 1991 PTS Rule (b) Ixtter from Mr. D. G. Mcdonald, Jr. (NRC) to Mr. R. E Denton *

(BG&E), dated May 24, 1993, Response to the 1991 Pressurized Hermal Shock (PTS) Rule,10 CFR 50.61, Calvert Cliffs Nuclear Power Plant, Unit No. 2 Pursuant to 10 CFR 50.90, the Baltimore Gas and Electric Company (BG&E) hereby requests an Amendment to Operating License No. DPR-69 by incorporating the changes described below into the Technical Specifications for Calvert Cliffs Unit No. 2.

4 DESCRIPTION ,

The proposed amendment would revise the Technical Specifications for Unit 2 to extend the use of the current heatup and cooldown curves to allow operation beyond 12 effective full power years (EFPY). ,

i HACKGROUND ,

i During the NRC's review of the Unit 2 Pressurized Thermal Shock (PTS) Rule response, additional  ;

information on the material chemistry for Unit 2 was needed for the NRC Staff review. On  !

February 16,1993, BG&E provided the requested information (Reference a). This response j provided the best estimate for the amount of copper and nickel in weld seams 2-203-A, B, and C as requested by the Staff. The NRC Staff concluded in the Safety Evaluation enclosed with 9311100237 DR 931101 l p ADOCK 05000318 fr ,i i  !

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Reference (b) that sufficient information from the welds that are similar to weld seams 2-203-A, B,  !

and C has been provided by BG&E to support its best estimate values of 0.16 weight percent copper l and 0.10 weight percent nickel for the subject weld seams. F The new values for copper and nickel content substantially improve the embrittlement projections  !

for Unit 2 weld 2-203-A, B, and C, the limiting weld in the Pressure-Temperature (P-T) limit  :

calculations. Current P-T limits assume a 0.12 percent copper and 1.01 percent nickel, and a fluence of 1.69x1019 n/cm2 (E>1 MeV). When the new metal values are used, plate D-8906-1 becomes limiting and the P-T limits are bounding for peak fluences up to 192x1019 n/cm 2 (E>1 MeV) at the  !

inside surface of the reactor vessel. Based on current fluence predictions, this fluence will extend the  !

applicability of the existing curves to approximately 13.8 EFPY. Since the vessel embrittlement is  !

actually based on fluence and not EFPY, we find it more appropriate to also base the heatup and l cooldown curves (Technical Specification Figures 3.4.9-1 and -2) on fluence. .

He current 12 EFPY heatup and cooldown curves for Unit 2 will expire at the earliest in mid-  !'

June 1994. This proposed change will extend the applicability of these curves to mid-1996.' During the 1995 refueling outage, a variable-setpoint low temperature overpressure protection (VLTOP) system is scheduled to be installed at Unit 2 to increase the allowable operating pressure band in the Minimum Pressure and Temperature (MPT) region. A License Amendment Request will be submitted at a later date proposing new heatup and cooldown curves and Low Temperature Overpressure Protection (LTOP) controls for Unit 2 to support the scheduled modifications to the  !

LTOP system (a similar request has already been submitted for Unit 1). This proposed change to l extend the current m es will allow the use of these current curves until the VLTOP system is -

implemented.  ;

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REOUESTED CIIANGE Change Unit 2 Technical Specifications Figure . 3.4.9-1 and Figure 3.4.9-2 and Technical Specification 3/4.4.9.3 and associated Bases as shown on the marked-up pages attached to this tra.."nittal.

l SAFI'lY ANALYSIS  !

Operation within the appropriate heatup and cooldown curves ensure that 10 CFR Part 50, i Appendix G P-T limits for the reactor pressure vessel will not be violated. The heatup and cooldown ,

curves are conservatively developed in accordance with the fracture toughness requirements of [

10 CFR Part 50, Appendix G, as supplemented by the American Society of Mechanical Engineers Boiler and Pressure Vessel Code Section III, Appendix G.

The proposed change to the Technical Specifications will extend the applicability of the existing l heatup and cooldown curves and rates from 1.69x1019 n/cm2 (E>1 MeV)-to 1.92x1019 n/cm l (E>1 MeV) to allow operation past the 1995 Unit 2 refueling outage. This extension is possible due -

to the new values approved for Unit 2 weld 2-203-A, B, and C (Reference b). This proposed change does not result in any changes to the LTOP controls currently in use for Unit 2.  ;

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- An additional change is being proposed for clarification. The operable high pressure safety injection l (HPSI) pump required in Technical Specificgtion 3/4.4.9.3 must be under manual control when the

• RCS temperature is less than or equal to 305 F and the reactor coolant system is vented to less than eight square inches. Manual control of the HPSI is achieved by placing the handswitch in pull-to- j 1

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4 Document Control Desk November 1,1993

.Page 3 lock, which will prevent the pump from starting automatically. This is currently controlled in plant i procedures and stated in footnotes for Specification 3.53 and Table 33-3. The revision to Technical Specification 3/4.4.93 ensures that when the HPSI pump is not in use, its handswitch is in pull-to- l; lock. His revision does not change the intent of the Technical Specification and is added for clarification only. His revision was approved for the Unit 1 Technical Specification in License Amendment No.177, dated December 22,1992.

DETERMINATION OF SIGNIFICANT HAZARDS The proposed change has been evaluated against the standards in 10 CFR 50.92 and has been determined to not involve a significant hazards censideration, in that operation of the facility in accordance with the proposed amendments:

1. Wou'd not involve a significant increase in the probability or consequences of an accident prev'ously evaluated.

Operation within the appropriate heatup and cooldown curves ensures that the 10 CFR Part 50, Appendix G, Pressure-Temperature (P-T) limits for the reactor pressure vessel will not be violated while operating at low temperature. The heatup and cooldown cunes are conservatively developed in accordance with the fracture toughness requirements of 10 CFR Part 50, Appendix G, as supplemented by the American Society of Mechanical Engineers Boiler and Pressure Vessel Code Section III, Appendix G. New values for the copper and nickel content have been approv d for the critical Unit 2 weld, which substantially improve the embrittlement projections for the limiting weld in the P-T limit calculations. His change extends the applicability of the current heatup and cooldown cunes until mid-1996. The proposed change will not result in any changes to the LTOP controls. Adding the requirement to Specification 3/4.4.93 to ensure the operable high pressure safety injection (HPSI) pump's handswitch will be placed in pull-to-lock when not in use is only a clarification and does not change the intent of the specification. This requirement for the operable HPSI pump is currently in footnotes for Specification 3.53 and Table 33-3. Herefore, the proposed dange does not involve a significant increase in the. +

probability or consequences of an accident previously evaluated.

2. Would not create the possibility of a new or different type of accident fmm any accident  ;

previously evaluated.

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Re proposed change to extend the current cun es to allow operation beyond 12 effective full power years (EFPY) does not represent a significant change in the configuration or operation of the plant. Specifically, no new hardware is being added to the plant as part of .

the proposed change, no existing equipment is being modified, nor are any different types of operations being introduced. The approval of the new chemistry for the limiting weld  ;

facilitates an extension of the applicability of the existing Unit 2 heatup and cooldown cunes.

His proposed change will not change any of the existing Unit 2 LTOP controls. - The addition of the requirement to have the HPSI pump's handswitch in pull-to-lock when not in use is only a clarification of the existing requirements. Therefore, the proposed change does not create the possibility of a new or different type of accident from any accident presiously evaluated.

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3. Would not involve a significant reduction in a margin ofsafety.

The proposed change will not affect the existing Appendix G limits. The extension of the -!

heatup and cooldown curves is a consequence of the new chemistry values for the limiting weld. The proposed change will not affect any margin of safety since the heatup and cooldown curves will continue to protect the Appendix G limits for all postulated transients. ,

The clarification to Specification 3/4.4.9.3 to require the operable HPSI pumps handswitch i be placed in pull-to-lock when not in use does not change the intent of the Specification.

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

i ENVIRONMENTAL ASSESSMENT The proposed amendment would change requirements with respect to the installation or use of a facility component located withm 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 i 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 l exposure. Therefore, the proposed amendment is eligible for categorical exclusion as set forth in j 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. ,

SCIIEDULE ,

i This change is requested to be approved and issued by May 15,1994 to allow implementation of the '

revised curves before the current curves expire. If the proposed revised curves are not approved prior to Unit 2 reaching the assumed peak fluence for the 12 EFPY, Unit 2 will be required to be shutdown. '

s SAFETY COMMITTEE REVIEW [

These proposed changes to the Technical Specifications and our determination of significant hazards  ;

have been reviewed by our Plant Operations and Safety Review Committee and OffSite Safety  !

Review Committee. They have concluded that implementing these changes will not result in an  :

undue risk to the health and safety of the public. j

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Document Control Desk

- November 1,1993 Page 5 Should you have any questions regarding this matter, we will be pleased to discuss them with you.

Very truly yours, L

STATE OF MARYLAND :

TO WIT : '

COUNTY OF CALVERT  :

I hereby certify that on the M ay of a Notary Public of the State of Maryland in and for Obkr ,1993, before me the subscriber,

( b /ty r t C o u d v ,

personally appeared Robert E. Denton, being duly sworn, and states that he is Vice P(esident of the +

Baltimore Gas and Electric Company, a corporation of the State of Maryland; that he provides the >

foregoing response for the purposes therein 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 Notarial Se:d:

Notary Public

'Ay Commission Expires: Ad 40' '

Datej RED /DJM/ dim nttachment: (1) U' nit 2 Technical Specification Revised Pages cc: D. A. Brune, Esquire J. E. Silberg, Esquire R. A. Capra, NRC . -

D. G. Mcdonald, Jr., NRC ,

T. T. Martin, NRC P. R. Wilson, NRC R. I. Mclean, DNR J. II. Walter, PSC I

i f