ML19308A185
| ML19308A185 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 12/19/1978 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Goodwin C PORTLAND GENERAL ELECTRIC CO. |
| References | |
| NUDOCS 7812290085 | |
| Download: ML19308A185 (1) | |
Text
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UNITED STATES
[ 9, NUCLEAR REGULATORY COMMISSION 3 J. I '
REGION V 0,
NE SUITE 202, WALNUT CREEK PLAZA o
1990 N. C ALIFORNIA BOULEVARD
- e,,*
WALNUT C REEK. CALIFORNI A 94596 December 19, 1978 Docket No. 50-344 Portland General Electric Company 121 S. W. Salmon Street Portland, Oregon 97204 ~
Attention: Mr. Charles Goodwin Assistant Vice President Gentlemen:
The enclosed IE Bulletin No. 78-14 is forwarded to you for information.
No written response is required. If you desire additional infomation regarding this matter, please contact this office.
Sincerely, q6b$-
R. H. Engelken Director
Enclosures:
1.
List of IE Bulletins Issued in 1978 cc w/ enclosures:
l4 B. Withers, PGE F. C. Gaidos, PGE F. Miller, Dept. of Energy Salem, Oregon r;,~
7 St ??9aus-
_m UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCDENT WASHINGTON,
?.
20555 December 19, 1978 IE Bulletin No. 78-lk DEIERIORATION OF BUNA-N COMPONENTS IN ASCO SOLENDIDS Description of Circu= stances:
Following a reactor scram at the Monticello Nuclear Power Station on July 27, 1978, one control rod was determined to have a slov scrat insertion time. While measuring the average control rod scrat insertion times (as required by Technical Specifications), the sate control rod failed to scra=.
Subsequent investigation revealed that a Buna-N disc Stall in the scran pilot valve solenoid core assenbly had fractured.
pieces of the Buna-N caterial vedged between the core assembly and the valve pilot body.
Th..s prevented proper movement of the core assently (plunger), and thus prevented the valve from properly venting control air fro: the scra= valves. A similar event occurred during scrat testing on June 5, 1978. On both occasions the control rod failed tc seras during control rod surveillance testing.
In these instances, had a seras occurred during normal operation of the reactor, the affected solenoid valves.
rods vould have inserted by stction of the backup sera The reactor was placed in cold shutdown on July 28, 1978. All of the pilot solenoid valves and scra= backup valves were disassembled scrat and inspected.
Six additional fractured Buna-N discs were found, all in scram pilot solenoid valves. Northern States Power Co=pany replaced the plunger Buna-N discs in all 2L2 scra= pilot valves and the 2 backup scram valves.
In addition to the Monticello failures, similar events were recently reported fro: the Big Rock Point and Pilgric facilities.
At Eig Rock Point, two failures were experienced in October while at Pilgric one failure was found in July and two in December. All of these failurer vere encountered during surveillance testing.
General Electric had previou,1y issued Service Infor=ation Letters, SIL 128 (March 31, 1975) and SIL 128 Revision 1 (January 30, 1976),
una-N components addressing the deterioration t i
in CRD scram pilot valves. Th progran be adopted which repla g pilot valves on a regularly se g DUPLICATE DOCUMENT Entire document previously entered into system under:
^= 7El?ZA 023o No of pages:
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