ML19345G187
| ML19345G187 | |
| Person / Time | |
|---|---|
| Site: | Satsop |
| Issue date: | 03/02/1981 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Dobson D WASHINGTON PUBLIC POWER SUPPLY SYSTEM |
| References | |
| NUDOCS 8103170006 | |
| Download: ML19345G187 (1) | |
Text
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UNITED STATES NUCLEAR REGULATORY COMMISSION o
,E REGION V 1990 N. CALIFORNIA Bout EVARD
- g,, e,&g SulTE 202, WAuduT CREEN PLAZA WALNUT CR EEK. CALIFORNIA 94506 March 2, 1981 c
en e
Docket Nos.30-508, 50-509 1/lRO G pgg
. Washington Public Power Supply System g
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P. O. Box 1223 p
Elma, Washington 98541 Attn: Mr. Dale Dobson, Acting Program Director Gentlemen:
The enclosed circular is forwarded for your infonnation. No written response to this circular is required.
If you have any questions related to this matter, please contact this office.
Sincerely, yk 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 G. C. Sorensen, WPPSS 8103170 @
SSINS No.: 6830 Accession No.:
80082202/1 IEC 81-03 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 i
March 2, 1981 IE Circular No. 81-03: IN0PERABLE SEISMIC MONITORING INSTRUMENTATION Description 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, approximatcly 25 to 75 miles from the Humboldt Bay Power Plant facility.
There were 12 separate seismic events above 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 knockea down, one highway overpass that collapsed, and unspecified damage that occurred 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 indicate i 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 schec'uled for routine servicing one week af ter the earthquake);
a buildup of dirt and dust appeared to uake 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 l
data.
l l
On January 24, 1980, an earthquake measuring 5.5 on the Richter Scale occurred about 10 miles north of Lawrence Live:more Laboratory (near San Francisco, California). Numerous af tershocks also occurred with one measuring 5.2 on January 26. The damage to civil structures was considered minor.
Rancho Seco Nuclear Plant, located approximately 45 miles northeast of the earth-quake area, reported no physical damage, although plant personnel felt slight building motion.
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' these earthquakes.
During this
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.n system was inoperable because on.
For the other instruments, 4
DUPLICATE DOCUMENT 1 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 ANOhddh2kh3-7{
No. of pages:
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