BSEP-96-0432, Submits Results of Core Shroud re-insp Completed During Refueling Outage 10 (B111R1).Cracking Is Typical IGSCC in Heat Affected Zone of Welds.Forwards Rev 0 to ESR 96-00160, ...Evaluation,B111R1 Core Shroud Insp
| ML20135E304 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 12/03/1996 |
| From: | Turkal M CAROLINA POWER & LIGHT CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20135E306 | List: |
| References | |
| BSEP-96-0432, BSEP-96-432, NUDOCS 9612110148 | |
| Download: ML20135E304 (3) | |
Text
l i
1 e*
CP&L y.m i
Carolina Power & Light Company P.O. Box 10429
)
Southport, NC 28461-0429 December 3,1996 j
SERIAL: BSEP 96-0432 U. S. Nuclear Regulatory Commission ATTENTION: Document Control Desk Washington, DC 20555 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NO.1 DOCKET NO. 50-325/ LICENSE NO. DPR-71 CORE SHROUD RE-INSPECTION RESULTS Gentlemen:
The purpose of this letter is to submit the results of core shroud re-inspections for the Brunswick i
Steam Electric Plant, Unit 1. These core shroud re-inspections were completed during the Unit 1 Refueling Outage 10 (B111R1). The Core Shroud Reinspection Plan for this refueling outage was submitted to the NRC staff by letter dated July 5,1996 (Serial Number BSEP 96-0245). of this letter provides the Unit 1 inspection results and evaluation.
The results of the inspections completed during the Unit 1 Refueling Outage 10 indicate that the reported cracking is typical intergranular stress corrosion cracking located in the heat affected zone of the welds. Using the results obtained during these inspections, a review of the core shroud structural capacity has been performed using the criteria established by tne BWRVIP in two NRC-approved documents, GE-NE-523-113-0894,"BWR Core Shroud Inspection and Flaw Evaluation Guidelines," Revision 1 and GE-NE-523-113-0894, Supplement 1, *BWR Core Shroud i
Distributed Ligament Length Computer Program." Based on the criteria contained in these documents, welds H1 lower, H4, H5, H6a, H6b, and H7 meet the L criteria for at least 2000 days of operation (i.e., three operating cycles). For the weld H1 upper, a limit load analysis was used to qualify the region for one cycle (600 days). This analysis was performed using j
actual ultrasonic testing (UT) depth data and assuming the uninspected regions are cracked to a starting depth of 0.44 inches (the average depth of the cracking found in the inspected regions of the weld H1 upper). No credit was taken for the backing fillet weld. Based on these inspections and evaluations, the condition of the core shroud does not impose restrictions to the operation of Brunswick Unit 1 during this operational cycle (Cycle 11).
Please refer any questions regarding this submittal to Mr. William Murray at (910) 457-2842.
[
]
Sincerely,
/
Mark A. Turkal Supervisor-Licensing Brunswick Nuclear Plant 090 @,
9612110148 961203 PDR ADOCK 05000325 PDR p
0 f
Document Control Desk l
BSEP 96-0432 / Page 2 i
WRM/wrm Enclosure 1.
ESR 96-00160, Revision 0, B111R1 Core Shroud Inspections cc:
U. S. Nuclear Regulatory Commission ATTN.: Mr. Stewart D. Ebneter, Regional Administrator 101 Marietta Street, N.W., Suite 2900 Atlanta, GA 30323-0199 Mr. C. A. Patterson NRC Senior Resident inspector - Brunswick Units 1 and 2:
U.S. Nuclear Regulatory Commission ATTN.: Mr. David C. Trimble, Jr. (Mail Stop OWFN 14H22) 11555 Rockville Pike Rockville, MD 20852-2738 The Honorable H. Wells Chairman - North Carolina Utilities Commission l
P.O. Box 29510 Raleigh, NC 27626-0510 i
l
\\
l l
]
ENCLOSURE 1 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NO.1 l
DOCKET NO. 50-325 LICENSE NO. DPR-71 NRC GENERIC LETTER 94-03, CORE SHROUD RE-INSPECTION RESULTS r
l i
i i
ENGINEERING SERVICE REQUEST (ESR) 96-00160, REVISION O j
B111R1 CORE SHROUD INSPECTIONS i
t i -
l
-