ML19209A437
| ML19209A437 | |
| Person / Time | |
|---|---|
| Site: | Humboldt Bay, Diablo Canyon |
| Issue date: | 09/13/1979 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Crane P PACIFIC GAS & ELECTRIC CO. |
| References | |
| NUDOCS 7910040019 | |
| Download: ML19209A437 (1) | |
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UNITED STATES I
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1990 N. CALIFORNI A DOULEVARD Y
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WALNUT CREEK, CALIFORNIA 94596 September 13, 1979 Docket tios. 50-133 50-275 50-323 Pacific Gas and Electric Company 77 Beale Street San Francisco, California 94106 Attention: Mr. Philip A. Crane, Jr.
Assistant General Counsel Gentlemen:
The enclosed IE Circular fio. 79-19 is fontarded to you for information.
fio written response is required. Should you have any questions related to your understanding of this matter, please contact this office.
Sincerely, hi,% y6b~
R. H. Erw ii e
Director
Enclosures:
1.
IE Circular tio. 70-19 2.
List of IE Circulars issued in the Last Six Months cc w/ enclosures:
W. Barr, PG&E gf} { W. Raymond, PG&E R. Ramsay, PG&E - Diablo Canyon E. Weeks, PG&E, Humboldt Bay J. Worthington, PG&E N 7910040o/7
v SSIMS: 6830 Accession No: 7908220111 UNITED STATES t!UCLEAR REGULATORY COMMISS10fl 0FFICE OF INSPECTION Atl0 ErlFORCEMENT WASHINGTON, D. C. 20555 September 13, 1979 IE Circular No. 79-19 LOOSE LOCKING DEVICES ON ItiGERSOLL-RAND PUMP IMPELLERS Description of Circumstances: Three reports have been submitted to the NRC regarding the loosening of locking devices on the impellers of pumps manufactered by the Ingersoll-Rand Company. The first report was subinitted as a significant deficiency (10 CFR 50.55(e)) by Arkansas Power and Light Company in letters of flarch 17, 1978 and May 9, 1978. The licensee reported excessive noise and vibrations in both Low Pressure SC sty Injection (LPSI) pumps during the preoperational test program on Unit 2 of Arkansas fluclear One (ANO). It was discovered that the washers, jam nut and cap nut used to retain the impellers were missing on botn pumps (Ingersoll-Rand Type 8X20WD). The licensee's corrective action involyed the installation of a tab washer. This corrective action was, also, taken on the containment spray pumps (Ingersoll-Rand Type 6X23WD) because of similarity of design. The second report was submitted by Duke Power Company in a licensee event report (LER 50-287/78-23) dated JanJary 24, 1979. The symptoms wera similar to those observed at ANO Unit 2 in that high vibration was detected in a reactor building spray pump (Ingersoll-Rand Type 4X11A) for Oconee Unit flo. 3. The licensee found that the impeller had worked loose. The corrective action included a revision to the mainteinance procedure to specify torque requirements. The ttird report was 10 CFR 21 Report flo. 79-01 submitted by Portland General Electric Co. on April 16, 1979. This report identified a deficiency that may exist in the Trojan fluclear Plant containment spray pumps (Ingersoll-Rand Type 6X23WD) in that there is a potential for the impeller lock nut to loosen. The potential deficiency was identified because of the similarity of the containment spray pumps design to the residual heat removal (RHR) pumps (Ingersoll-Rand Type 8X20WD) and the discovery of a loose lock nut on an RHP. pump during pump maintenance. The corrective action was to provide a positive mechanical lock on the impeller nut. j j g 4 ,r} y Westinghouse fluclear Service Division has i.;ued a Technical Bulletin to Westing-house plant owners on loose lock nuts ' ~ ~ " ' -d ""r pumps. Excerpts from that Technical 8' Engineering, Inc. has, also, informed DUPLICATE DOCUMENT same problem in a letter dated March 1 Enclosure fio. 2. Entire document previously entered
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