ML19323D621
| ML19323D621 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 04/21/1980 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Dunn C DUQUESNE LIGHT CO. |
| References | |
| NUDOCS 8005220035 | |
| Download: ML19323D621 (1) | |
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$31 PARK AVENUE e7 MING OP PRUS$1 A. PENNSYLVANI A 19406 April 21, 1980 Docket No. 50-334 Duquesne Light Company ATTN:
Mr. C. N. Dunn Vice President Operations Division 435 Sixth Avenue Pittsburgh, Pennsylvania 15219 Gentlemen:
The enclosed IE Information Notice No. 80-15, " Axial (Longitudinal) Oriented Cracking in Piping," is forwarded to you for information.
No written response is required.
If you desire additional information regarding this matter, please contact this office.
Sincerely, N
Boyce H. Grier
" Director
Enclosures:
1.
IE Information Notice No. 80-15 2.
List of Recently Issued IE Information Notices CONTACT:
L. E. Tripp (215-337-5282) cc w/encls:
F. Bissert, Technical Assistant Nuclear R. Washabaugh, QA Manager J. Werling, Station Superinteident G. Moore, General Superintendent, Power Stations Department J. J. Carey, Director of Nuclear Operations R. Martin, Nuclear Engineer J. Sieber, Superintendent of Licensing and Compliance, BVPS 8005s20075
I ENCLOSURE 1 SSINS No.:
6870 Accession No.
UNITED STATES 8002280660 i
NUCLEAR REGULATORY COMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 I
IE Information Notice No. 80-15 Date:
April 21, 1980 Page 1 of 1 AXIAL (LONGITUDINAL) ORIENTED CRACKING IN PIPING On March 8, 1980, the Commonwealth Edison Company reported to the NRC that slight leakage was observed from the "A" loop core spray injection piping during a reactor coolant system leakage test at their Quad-Cities Unit 2 Nuclear Power Station.
The source of leakage was subsequently identified to be located adjacent to a shop weld joining a 90* elbow and a wedge section of elbow material used to extend the elbow to 105*.
Subsequent ultrasonic inspec-tions revealed additional cracking in several other elbows in "A" and "B" core j
spray loops.
The cracks ate located adjacent to welds and oriented transverse to the weld in the axial (longitudinal) piping direction.
The affected elbows have been removed and currently failure analyses are in progress.
Preliminary results from liquid penetrant examinations of the elbow interior surface in the counter bore / weld root area revealed axial oriented cracks on both sides of the weld in the counter bores adjacent to the weld roots.
From the limited metallography performed to date, the cracking mode appears to be intergranular stress corrosion cracking.
The cracking, however, only appears to be slightly branched.
A determination as to whether or not the cracking extends into and across the welds cannot be made at this time.
It is significant to point out that these service sensitive lines, as defined by NUREG 313, had been examined on an augmented basis per NUREG 313 requirements.
Two of the affected welds were inspected ultrasonically at the current outage prior to the leakage being observed at the pressure test with no indication of cracking reported.
Further ultrasonic examinations, using standard ASME Section XI methods, performed after discovery of the leak clearly revealed the cracking (approximately 100% over the reference level).
Licensees are requested to inform NDE inspection personnel of the above stated information and to emphasize the need for care when performing circumferential UT scans of the weld and adjacent areas in piping components.
Particular importance should be stressed when the examinations are performed on BWR service sensitive 304 stainless steel piping and on PWR 304 stainless steel piping in stagnant systems.
This Information Notice is provided as an early notification of a possibly significant matter that is still under review by the NRC staff.
It is expected that recipients will review the information for possible applicability to their facility.
No specific action or response is requested at this time.
If you have any questions regarding this matter, please contact the Director of the appropriate NRC Regional Office.
l
ENCLOSURE 2 IE Information Notice No. 80-15 Date:
April 21, 1980 Page 1 of 1 RECENTLY ISSUED IE INFORMATION NOTICES Information Subject Date Issued to Notice No.
Issued 80-05 Chloride Contamination of 2/8/80 All Power Reactor Facil-Safety Related Piping and ities with an Operating Components License (OL) or Construction Permit (CP) and applicants for a CP 80-06 Notification of Signif-2/27/80 All Power Reactor Facil-icant Events ities with an OL and applicant for OL 80-07 Pump Fatigue Cracking 2/29/80 All Power Reactor Facil-ities with an OL or CP 80-08 The States Company Sliding 3/7/80 All Power Reactor Facil-Link Electrical Terminal ities with an OL or CP Block 80-09 Possible Occupational Health 3/7/80 All Power Reactor Facil-Hazard Associated with Closed ities with an OL or CP Cooling Systems for Operating Power Plants 80-10 Partial Loss of Non-Nuclear 3/7/80 All Power Reactor Facil-Instrument System Power Sup-ities with an OL or CP ply During Operation i
80-11 Generic Problems With ASCO 3/14/80 All Power Reactor Facil-Valves in Nuclear Applica-ities with an OL or CP, tions including Fire Pro-Fuel Fabrication and tection Systems Processing Facilities 80-12 Instrument Failure causes 3/31/80 All Power Reactor Facil-Opening of PORV and Block ities with an OL or CP Valve 80-13 General Electric Type SBM 4/2/80 All Power Reactor Facil-Control Switches - Defective ities with an OL or CP CAM Followers 80-14 Safety Suggestions from 4/2/80 All Power Reactor Facil-Employees ities with an OL or CP, Fuel Fabrication and Processing Facilities and Materials Priority 1 Licensees
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