ML20197G129

Safety Evaluation Accepting Revised Withdrawal Schedules for Plant,Units 1 & 2

ML20197G129
Person / Time
Site:	Calvert Cliffs
Issue date:	12/15/1997
From:	NRC (Affiliation Not Assigned)
To:
Shared Package
ML20197G115	List: ML20197G110 ML20197G129
References
NUDOCS 9712300380
Download: ML20197G129 (5)

Text

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. WAsMINeToN, D.C. 3000H001 SAFETY EVALUATION SY THE OFFICE OF NUCLEAR REACTOR REGULATION BALTIMORE GA8 AND ELECTRIC COMPANY'8 REVISION TO THE REACTOR VESSEL SURVElLLANCE CAP 8ULE WITHDRAWAL SCHEDULE FOR CALVERT CLIFFS NUCLEAR POWER PLANT. UNIT NOS.1 & 2 i

DOCKET NOS. 50-317 AND 50-318

1.0 INTRODUCTION

In a letter dated June 20,1997, Gehimore Gas and Electric Company (BGE) submitted, for NRC approval, their proposed withdrawal schedule, which was based on the American Society for Testing and Materials (ASTM) E185 70 and E185 82 recommendations and reflected updated fluence information from the surveillance capsules removed in 1992 and 1993 from Calvert Cliffs Units 1 and 2, respectively.

2.0 BACKGROUND

The surveillance program for Calvert Cliffs Units 1 and 2 was implemented to monitor the radiation-induced changes in the mechanical and impact properties of the pressure vessel materials. This surveillance program was established in accordance with 10 CFR Part 50, Appendix H, and ASTM E185 70. By letter dated October 27,1995, the licensee provided a revision to the reactor vessel surveillance capsule withdrawal schedule for Calvert Cliffs Units 1 and 2. This request was made in accordance with Appendix H of 10 CFR Part 50, and not as a license amendment request, since the surveillance capsule withdrawal schedule was no longer part of the Calvert Cliffs Technical Specifications.

Subsequently, by letter dated February 23,1996, the licensee withdrew the request for approval l that was indicated in the October 27,1995, letter. By letter dated June 20,1997, the licensee .

resubmitted for approval, pursuant to Appendix H of 10 CFR Part 50, a revision to the schedule for withdrawal of reactor vessel surveillance capsules for Calvert Cliffs Units 1 and 2.

BGE has included 6 capsules, of which 5 are scheduled for removal and 1 is standby, in the -

reactor vessel surveillance program for each of the Calvert Cliffs units. In addition, BGE has included a supplemental surveillance capsule for Unit 1 in its proposed surveillance capsule withdrawal schedale.

For Units 1 and 2, the capsules at the 263' location were removed for the first interval instead of the 97' capsules as was called for by the originally approved schedule. NRC approval for this

, change was provided for Units 1 and 2 in the letters dated February 2,1982, and December 23,

-1992, respectively, in each unit, the surveillance capsule at the 97' location was removed for .

the second interval instead of the capsule located at the 104* location, as was called for by the

' schedule approved in 1982. NRC approval for this chan9e to the Unit 1 and Unit 2 withdrawal schedules was provided in letters dated March 11,1992 and December 23,1992, respectively.

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L . In accordance with the ' current Unit 1 capsule withdrawal schedule, the 284' capsule is scheduled to be removed next. However, the most recent fluence analyses show that the lead .

factor for this capsule is low, and it will not be able to attain enough fluence by the end of the current license to meet any of the fluences recommended by ASTM E185-70 or-82. Therefore, in the revised withdrawal schedule for Unit 1, N was proposed that the 83' capsule be withdrawn

, instead. The 83' capsule has a higher lead factor than the 284* capsule and can reach a l fluence recommended by the ASTM standard by the year 2004. The two capsules comain j

identical dosimetry, temperature monitors, and surveillance materials.

BGE also provided its proposed withdrawal schedule for the supplemental surveillance capsule, j placed in the Unit i reactor vessel at the 263' location, following the withdrawal of the original i capsule. The supplemental surveillance program will provide additional surveillance data for the  !

l Unit 1 axial weld seams 2 203 A, B, and C. Axial seems 2 203 A, B, and C were fabricated by Combustion Engineering using weld wire heat numbers 202g1 and 12008. When removed in the

year 2000, the capsule will be sectioned into two halves, with one-half removed for testing. The l' . second half will be reconstituted for reinstallation in the 263' location and will be removed for

= final analysis in the year 2012.

Data from this program will be used to verify the embrittlement observed at low to intermediate fluence levels from the wold samples in the McGuire Unit 1 surveillance program. The weld i

samples in the McGuire Unit 1 surveillance program are being used to determine the

! embrittlement in the viel seems 2-203-A, B, and C in Calvert Cliffs Unit i because they were fabricated using the same weld wire heat numbers as the intermediate shell axial welas in Calvert Cliffs Unit 1, heat numbers 202g1 and 12008. The supplemental surveillance capsule

, test results will support the application of the McGuire Unit 1 surveillance data to predict the embrittlement of Unit 1 weld seams 2-203 A, B, and C.

3.0 EVALUATION Appendix H to 10 CFR Part 50, " Reactor Vessel Material Surveillance Program Requirements,"

include criteria to monitor changes in the fracture toughness properties of ferritic materials in the reactor vessel beltline region of light water nuclear power reactors which result from exposure of these materials to neutron irradiation and the thermal environment. Appendix H to 10 CFR Part 50 endorses ASTM E185, " Surveillance Tests for Nuclear Reac. tor Vessels." Appendix H states that "the design of the surveillance program and the withdrawal schedule must meet the requirements of the edition of ASTM E185 that is current on the issue date of the ASME Code to

which the reactor vessel tsas purchased.

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- As indicated in the Calvert Cliffs Updated Final Safety Analysis Report, the Calvert Cliffs Units 1 4 and 2 surveillance programs comply with 10 CFR Pa:150, Appendix H, and ASTM E185-70.

! Because this edition 'of the standard was current at the time the reactor vessels were purchased, the Calvert Cliffs Units 1 and 2 surveillance capsule withdrawal schedules satisfy the requirements of Appendix H to 10 CFR Part 50. In addition, the licensee has implemented the

- ASTM E185-82 Standard, to the maximum extent possible, for the remaining capsules in the Calvert Cliffs Units 1 and 2 withdrawal schedules. The staff verified that the subject withdrawal schedules satisfy the requirements of ASTM E185-70.

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3-By ASTM E185 70, it is recommended that the capsules be withdrawn at thrse or more separate times. The first capsule withdrawal shall correspond to the neutron exposure of the reactor vessel at no greater than 30 percent of its design life. The other capsule withdrawal shall correspond to the neutron exposure of the reactor vessel near the end of its design life. BGE has included 6 capsules, of which 5 are scheduled for removal and 1 is standby, in the reactor -

vessel surveillance program for each of the Calvert Cliffs units, in addition,- BGE has included a - y supplemental surveillance capsule for Unit 1 in its proposed surveillance capsule withdrawal  !

schedule.

Currently, the licensee has tested 2 capsules for each of the units. The staff verified that a capsule from each of the Calvert Cliffs Units 1 and 2 corresponood to the neutron exposure of

= the reactor vessel at no greater than 30 percent of its design life. The licensee has also

- scheduled for the testing of 3 additional capsules for each of the units. BGE has scheduled the

remaining 3 capsules of each unit to follow the recommended schedule of ASTM E185-82 to the maximum extent possible. The stan verified that a capsule from each unit is scheduled to be withdrawn which will correspond to the neutron exposure of the reactor vessel near the end of its design life. The end of license fluences for Calvert Cliffs Units 1 and 2 are 4.31E19 and 3.88E19, respectively. A list of the status of the Calvert Cliffs Units 1 and 2 surveillance capsules is provided in Enclosure 2.

The staff evaluated the withdrawal schedule for Calvert Cliffs Units 1 and 2 and determined that the withdrawal schedules were prepared in accordance with Appendix H to 10 CFR Part 50. The staff verified that the proposed capsule withdrawal schedule complied with ASTM E185-70 ano

, ASTM E185 82 to the maximum extent possible. The staff also found the schedule for the supplemental surveillance program acceptable.

4.0 CONCLUSION

l Based on the staff's review of BGE's submittal, the staff found that the revised v.1thdrawal schedules are acceptable for Calvert Cliffs Units 1 and 2. The proposed withdrawal schedules satisfy the ASTM E185 70 Standard. Since this edition of %e standard wcs current at the time the reactor vessels were purchased, the Calvert Cliffs Units 1 and 2 surveillance capsule l - withdrawal schedules satisfy the requirements of Appendix H to 10 CFR Part 50. Therefore, the

, staff approves the revised withdrawal schedules for Calvert Cliffs Units 1 and 2.

5.0 REFERENCES

1. ' Letter from Mr. C.H. Cruse (BGE) to NRC Document Control Desk, dated June 20,1997, "Resubmittal of Request for Approval: Revision to Reactor Vessel Surveillance Capsule Withdrawal Schedule."

2. United States of America Nuclear Regulatory C,ommission, Memorandum and Order, CLI l 13, Docketed and Served December 6,1996, in the Matter of the Cleveland Electric illuminating Company, Perry Nuclear Power Plant, Unit 1, Docket No. 50-440-OLA 3.

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3. _ Code of Federal Regulations, Thie 10, Part 50, Appendix H, " Reactor Vessel Material Surveillance Program Requirements," December 1995.

a. American Society for Testing and Materials, " Standard Recommended Practice for Surveillance Tests for Nuclear Reactor Vessels," ASTM E185 70.

5. American Society for Testing and Materials, " Standard Recommended Practice for Surveillance Tests for Nuclear Reactor Vessels," ASTM E185-82.

6. NUREG-1511. " Reactor Pressure Vessel Status Report," Dscomber 1994.

Pdncipal Contributor: M. Khanna Date: December 15, 1997 i

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. STATUS OF CALVERT CLIFFS L' NIT 1 SURVEILLANCE CAPSULES CAPSULEIDf TARGET FLUENCE STATUS AZIMUTHAL POSITION -  ;

263* 0.62E19 TESTED >

97* 2.64E19 TESTED 83* 3.47E19 TO BE TESTED 4 104' 3.14E19 TO BE TESTED 277' 4.31E19 TO BE TESTED 284' - STANDBY STATUS OF CALVERT CLIFFS UNIT 2 SURVEILLANCE CAPSULES CAPSUL.E IDI TARGET FLUENCE STATUS AZIMl1 THAL POSITION 263* 8.06E18 TESTED

, 97* 1.85E19 TESTED 224' 2.04E19 TO BE TESTED 104* 3.02E19 TO BE TESTED 277' 3.88E19 TO BE TESTED 83* - STANDBY STATUS OF CALVERT CLIFFS UNIT 1 SUPPLEMENTAL SURVEILLANCE CAPSULES

. CAPSw .!1D/ TARGET FLUENCE STATUS

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AZIMUTHAL POSITION S1 1.00E19 TO BE TESTED S2 1.93E19 TO BE TESTED Enclosure 2