ML20154G354
| ML20154G354 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 10/05/1998 |
| From: | Dromerick A NRC (Affiliation Not Assigned) |
| To: | Cruse C BALTIMORE GAS & ELECTRIC CO. |
| Shared Package | |
| ML20154G358 | List: |
| References | |
| TAC-MA2456, NUDOCS 9810130133 | |
| Download: ML20154G354 (5) | |
Text
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1 UNITED STATES g-j NUCLEAR REGULATORY COMMISSION s
o WASHINGTON, D.C. 20es6 0001 October 5,1998 Mr. Charles H. Cruse Vice Fresident Nuclear Energy-Baltimore Gas and Electric Company Calvert Cliffs Nuclear Power Plant 1650 Calvert Cliffs Parkway Lusby, MD 20657
SUBJECT:
CALVERT CLIFFS NUCLEAR POWER PLANT, UNIT NO. 2 - EVALUATION OF THE PRESSURIZER INSTRUMENT NOZZLE REPAlR (TAC NO MA2456)
Dear Mr. Cruse:
By letter dated August 4,1998, the Baltimore Gas and Electric Company (the licensee) submitted, for NRC review, its flaw tolerance evaluation for an assumed flaw in the inboard l
Instrument weld of the pressurizer for Calvert Cliffs Nuclear Power Plant, Unit No. 2. During a j
walkdown while Unit 2 was in hot standby (Mode 3), the licensee detected leakage from the pressurizer upper level tap (instrument nozzle 2-LT-110-X). As a result, the licensee performed ultrasonic (UT) examination of the pressurizer vessel shell. The inspection results showed no defects in the vessel shell. However, no UT examination was performed on the weld of the pressurizer instrument nozzle. In the subsequent repair, the licensee welded the outboard portion of the nozzle to a weld pad on the outside of the pressurizer head to form a new pressure i
boundary for the coolant. No repair of the inboard instrument weld where the leakage was identified was performed. Instead, the licensee utilized the evaluation procedure and criteria in Appendix A of Section XI of the American Society of Engineers (ASME) Code to demonstrate that the assumed crack is acceptable without repair for the design life of the vessel which includes 500 heatups and cooldowns.
The NRC staff completed the review and concluded that the flaw tolerance evaluation meets the rules of the ASME Code. Since the predicted number of heatups and cooldowns needed to i
reach the allowable flaw depth is far greater than the number of design cycles, the staff concluded that the pressurizer of Calvert Cliffs Unit 2 should be able to operate with a flaw in the instrument weld. However, to ensure that the flaw does not grow to s critical size during the remaining life of the pressurizer, the staff has requested the licensee to provide an inspection plan for future outages. The licensee indicated in a letter dated August 25,1998, that it will perform an inspection in the next outage and will make the results of the inspection available to the NRC. In addition, the licensee is committed to provide an action plan for inspection of the l
pressurizer instrument nozzle weld flaw by February 26,1999. The staff will review all information at that time and determine whether the unit can be operated with a flaw in the l
instrument weld to the expiration of the license.
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Enclosed is the staff's safety evaluation. BGE followed the procedure and criteria in Appendix A of Section XI of the ASME Code in demonstrating that the pressurizer of Calvert Cliffs Unit 2 should be able to operate with a flaw in the instrument weld. The quality in preparing the submittal is very good. This completes the staffs effort for TAC No. MA2456.
Sincerely, l
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Alexander W. Dromerick, Senior Project Manager Project Directorate 1-1 Division of Reactor Projects - 1/l1 Office of Nuclear Reactor Regulation Docket No. 50-318
Enclosure:
Safety Evaluation ec/w enc!: See next page i
i
October 5,1998 C.' Cruse Enclosed is the staffs safety evaluation. 3GE followed the procedure and criteria in Appendix A of Section XI of the ASME Code in demonstrating that the pressurizer of Calvert Cliffs Unit 2 should be able to operate with a flaw in the instrument weld. The quality in preparing the submittal is very good. This completes the staff's effort for TAC No. MA2456.
l Sincerely, l'
l-l Originel Signed by:
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Alexander W. Dromeric.k Senior Project Manager Project Directorate 1-1 Division of Reactor Projects - 1/II
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Office of Nuclear Reactor Regulation l
. Docket No. 50-318 l
Enclosure:
Safety Evaluation cc/w encl: See next page DISTRIBUTION:
Seeket Fileg PUBLIC
. PDi-1 R/F
~ J. Zwolinski S. Bajwa l
S. Little A. Dromerick S. Sheng T. Harris (e-mail only, TLH3) safety evaluation i
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ACRS C.. Hehl, Region i l!-
- DOCUMENT NAME: G:\\CC1-2\\MA2456.LTR To receive a copy of this document, indicate in the box: "C" = Copy wi'.hout attachment / enclosure "E" = Copy with
' attachment / enclosure "N" = No copy -
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SLitt W SBajwe /f/7 DATE AF7/)f/96 09/lS/98 W/ f/98 '
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Octobsr 5,1998 i
C. Cruse l Enclosed is the staffs safety evaluation. BGE followed the procedure and criteria in Appendix A of Section XI of the ASME Code in demonstrating that the pressurizer of Calvert Cliffs Unit 2 should be able to operate with a flaw in the instrument weld. The quality in preparing the submittalis very good. This completes the staffs effort for TAC No. MA2456.
t Sincerely, Original Signed by:
Alexander W. Dromerick, Senior Project Manager Project Directorate 1-1 Division of Reactor Projects - 1/ll Office of Nuclear Reactor Regulation Docket No. 50-318
Enclosure:
Safety Evaluation cc/w encl: See next page l
DISTRIBUTION:
Docket File PUBLIC PDI-1 R/F J. Zwolinski S. Bajwa S. Little A. Dromerick S. Sheng T. Harris (e-mail only, TLH3) safety evaluation OGC ACRS C. Hehl, Region i DOCUMENT NAME: G:\\CC1-2\\MA2456.LTR To receive a copy of this document, indicate in the box: "C" = Copy without attachment / enclosure "E" = Copy with attachment / enclosure "N" = No copy 0FFICE Mgp(-A// /
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NAME AQrJnWJck/rst SLitt W SBaJn ef/7 DATE M/(f?98 09/l%/98 99/ f/98 '
l OfficiM Record Copy I
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s Mr. Charles H. Cruse.
j Baltimore Gas & Electric Company Calvert Cliffs Nuclear Power Plant i-cc' i
President Mr. Joseph H. Walter, Chief Engineer i
Calvert County Board of Public Service Commission of i
Commissioners Maryland 175 Main Street Engineering Division Prince Frederick, MD 20678 6 St. Paul Centre Baltimore, MD 21202-6806 James P. Bennett, Esquire j.
Counsel Kristen A. Burger, Esquire Baltimore Gas and Electric Company Maryland People's Counsel P.O. Box 1475 6 St. Paul Centre Baltimore, MD 2n J3 Suite 2102 Baltimore, MD 21202-1631 Jay E. Silberg, Esquire 3
Shaw, Pittman, Potts, and Trowbridge Patricia T. Bimie, Esquire 2300 N Street, NW Co-Director Washington, DC 20037 Maryland Safe Energy Coalition P.O. Box 33111 L
Mr. Bruce S. Montgomery, Director Baltimore, MD 21218
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NRM l
Calvert Cliffs Nuclear Power Plant Mr. Loren F. Donatell l
1650 Calvert Cliffs Parkway NRC Technical Training Center Lusby, MD 20657-4702 5700 Brainerd Road 2
Chettanooga, TN 37411-4017 i
Resident inspector 4
U.S. Nuclear Regulatory i
Commission P.O. Box 287 J
St. Leonard, MD 20685 i
. Mr. Richard I. McLean, Manager
- Nuclear Programs Power Plant Research Program Maryland Dept. of Natural Resources -
Tawes State Office Building,83 Annapolis, MD 21401 Regional Administrator, Region i U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 a
.