ML20206K620
| ML20206K620 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 04/15/1987 |
| From: | Trevors G NEBRASKA PUBLIC POWER DISTRICT |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| RTR-NUREG-0619, RTR-NUREG-619 CNSS877179, TAC-43402, NUDOCS 8704170012 | |
| Download: ML20206K620 (3) | |
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COOPER NUCLEAR STATION Nebraska Public Power iistrict
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CNSS877179 April 15, 1987 U.S. Nuclear Regulatory Commission Document Control Desk Washington, D.C.
20555
Subject:
Report of Cooper Nuclear Station Feedwater Nozzle Examinations per NUREG 0619.
Gentlemen:
In accordance with Section 4.4.3.1(2) of NUREG 0619, "BWR Feedwater Nozzle and Control Rod Drive Return Line Nozzle Cracking", the following report of ultrasonic and visual examinations of the feedwater nozzles and spargers at Cooper Nuclear Station is presented.
(a) There have been eight startup/ shutdown cycles at Cooper Nuclear Station since the latest visual examination of the feedwater spargers in 1984, and 16 startup/ shutdown cycles since the latest ultrasonic examination of the feedwater nozzles in 1982.
There have been a total of 109 s*tartup/
shutdown cycles at Cooper Nuclear Station since the initial startup of the plant in 1974.
NOTE:
A deviation occurred in the ultrasonic examination interval (as specified in Table 2 of NUREG 0619) when this exam was inadvertently omitted from the 1984/1985 outage Inservice Inspection schedule. This omission was detected by the utility during the Fall 1986 refueling outage.
Consequently, the required ultrasonic examinations were immediately performed with satisfactory results.
No deviations in the visual or liquid penetrant examination intervals occurred.
Corrective actions are being reviewed to prevent recurrence of this deviation.
(b)
In 1990, Cooper Nuclear Station removed the feedwater nozzle cladding and installed double-piston-ring, triple-thermal-sleeve spargers.
Subsequent to this, baseline ultrasonic and liquid penetrant examinations were performed per Cooper Nuclear Station and General Electric procedures. No cracks or recordable indications were identified during these examinations.
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4 U.S. Nuclear R guletory Commission April 15, 1987 Page 2 In 1982, the feedwater nozzles and spargers were examined by ultrasonic and visual methods, respectively, per Cooper Nuclear Station and General Electric procedures. No cracks or recordable indjcations were identified during these examinations.
In 1983 and 1984, the feedwater spargers were virually examined per the aforementioned procedures.
No cracks or recordable indications were identified during these examinations.
(c) There have been no changes to procedures or systems that would affect the feedwater temperature or flow.
(d) There were no recordable indications identified from ultrasonic and visual examinations of the feedwater nozzles and spargers in the 1986 examination.
(e) Cooper Nuclear Station does not utilize a leakage monitoring device.
(f) There were no crack-like indications identified from ultrasonic examinations performed in 1986. The following procedures were used for the ultrasonic examination of the three examination zones in each feedwater nozzle.
Zone Procedure Region
- 1 GE #NIRZl-W812 Inner radius of nozzle-to-vessel junction.
For Zones 1 and 2, a manual pulse-echo ultrasonic technique was used.
This examination method utilizes an angle beam shear wave technique to identify crack indications.
For Zone 3, a manual pulse-echo ultrasonic technique was used to examine the inner bore region of the feedwater nozzles.
This examination method requires the use of circumferentially directed shear waves scanned in two opposite directions around the inner bore of the nozzle to identify crack indications.
Personnel performing the aforementioned ultrasonic examinations were certified to at least Level I and trained on a nozzle mock-up utilizing the techniques described herein.
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- U.S.. Nuclear R2gulatory Commission April 15, 1987
'Page'3-1 Please contact E. M. Mace, Engineering Manager at Cooper Nuclear Station, if you should require additional information regarding this matter.
Sincerely, G. A Trevors i
Division Manager of Nuclear Support GAT:SSF:ss cc: NRC Regional Office Region IV NRC Resident Inspector Cooper Nuclear Station 1
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