ML19345G186
| ML19345G186 | |
| Person / Time | |
|---|---|
| Site: | Washington Public Power Supply System |
| Issue date: | 03/02/1981 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Mazur D WASHINGTON PUBLIC POWER SUPPLY SYSTEM |
| References | |
| NUDOCS 8103170005 | |
| Download: ML19345G186 (1) | |
Text
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((b st.m u co Utit (ED STATES
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[ y g #/:. s (f(,g NUCLEAR REGULATORY COMMISSION REGION V
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1990 N. CALIFORNIA BOULEVARD o,
%, *' Q SUITE 202. WALNUT CREEK PLAZA
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WALNUT CREE K, CALIFORNIA 94596 March 2, 1981 Docket Nos. 50-460, 50-513 80 t"-
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Washington Public Power Supply System D
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P. O. Box 968 g4
[j 3000 George Washington Way
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Richland, Washington 99352 3'p,
Attn: Mr. D. W. Mazur Program Director, WNP-1/4 Gen ^lemen:
Tha enclosed circular is forwarded for your information. No written response to this circular is required.
If you have any questions related to this matter, please contact this office.
Sincerely, R. H. Engelken Director
Enclosure:
1.
IE Circular No. 81-03 2.
List of IE Information Notice Recently Issued cc w/ enclosures:
M. E. Witherspoon, Quality Assurance Director, WPPSS G. C. Sorensen, WPPSS 8103170Ogg
SSIflS fio. : 6830 Accession fio.:
8008220271 IEC 81-03 UflITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ErlFORCEMENT l
WASHIfiGTON, D.C.
20555 f! arch 2, 1981 IE Circular flo. 81-03: INOPERABLE SEISMIC MONITORING INSTRUMENTATIO!!
Descripticn of Circumstances:
On November 8, 1980, an earthquake occurred off the coast near Eureka, California.
The earthquake was reported to have a magnitude of 7.0 on the Richter Scale at the epicenter, approximately 25 to 75 miles from tFe Humboldt Bay Power Plant facility. There were 12 separate seismic events a! ave a magnitude of 3.5 that occurred within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of the earthquake, the largest event measuring 5.2.
Reported damage to structures included several houses that were moved off supporting posts, various chimneys that were knocked down, one highway overpass that collapsed, and unspecified damage that occurre6 at two pulp mills. There were three potentially different sources of plant response data: three sets of magnetic tape triaxial accelograph recorders; three sets of triaxial film recorders (passive device); and one set of triaxial response spectrum recorders (passivedevice). A review of the records from these instruments indicated the following: the magnetic tape triaxial recorders did not produce useful records due to a degraded low-voltage power supply in the recording system (previously scheduled for routine servicing one week after the earthquake);
a buildup of dirt and dust appeared to make inoperable six of the nine film recorders (the readings from the other three are considered highly unreliable and were not obtained from the same set of triaxial recorders); the triaxial response spectrum recorder was the only instrument believed to produce reliable i
data.
On January 24, 1980, an earthquake measuring 5.5 on the Richter Scale occurred about 10 miles north of Lawrence Livermore Laboratory (near San Francisco, Calif 6rnia). Numerous aftershocks also occurred with one neasuring 5.2 on January 26. The damase to civil structures was considered minor. Rancho Seco Nuclear Plant, loca9d approximately 45 miles northeast of the earth-quake area, reported no pnysical damage, although plant personnel felt slight building motion.
Ra
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- g these earthquakes.
During this on system was inoperable because ion.
For the other instruments, DUPLICATE DOCUMENT al cable problems. Whether the or not is unclear because the Entire document previously site did not trigger.
Records entered into system under:
ions from 1 to 1.5 g and 0.1 g xNo 8$08MGd.7 /
N o. of pages:
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