ML19318B791
| ML19318B791 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 05/14/1980 |
| From: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | Eric Turner HOUSTON LIGHTING & POWER CO. |
| References | |
| NUDOCS 8006300062 | |
| Download: ML19318B791 (1) | |
Text
a a-i.N LPDR TIC v UNITED STATES.
/s ** ** t o,,'o, NUCLEAR REGULATORY COMMISSION NSIC CENTRAL FILES
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ARLINGTON, T EX AS 76012 o, ;p.% ~ %T.-
y May 14. 1980
'In Reply Refer To:
RIV Docket Nos. 50-498/IE Circular'No. 80-12
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50-499/IE Circular No. 80-12 Houston Lighting & Power Company ATTN: Mr. E. A. Turner, Vice President Power Plant Construction and Technical Services Post Office Box 1700 Houston, Texas 77001 Centlemen:
The enclosed IE Circular No. 80-12, is forwarded to you for information..If there are any questions related to your understanding of the suggested actions, please contact this office.
Sincerely,
- Q,' /
I f t'
. )G t
Karl V.
eyfrit Director
Enclosures:
1.
IE Circular No. 80-12 2.
List of Recently Issued IE Circulars f
80.06800061
SSINS No.: 6830 UNITED STATES Accession No.:
NUCLEAR REGULATORY COMMISSION 800505005; 0FFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 IE Circular No. 80-12 Date:
May 14, 1980 Page 1 of 2 VALVE-SHAFT-TO-ACTUATOR KEY MAY FALL OUT OF PLACE WHEN MOUNTED BELOW HORIZONTAL AXIS Description of Circumstances:
Tennessee Valley Authority has identified and reported to the NRC a nonconformance on a Bettis Robot-Arm actuator installed on a Pratt Butterfly Valve at the Sequoyah nuclear plant.
It is reported (ref. attached 10 CFR 50.55(e) report) that a valve became inoperable when the valve-shaft-to-actuator key fell out of place.
It is further noted that the orientation of this valve assembly was such that the operator was on the bottom of the valve (below the horizontal axis).
The Pratt Butterfly Valve furnished with Bettis actuator is designed with a press-fit keyway connection valve /actustor. We believe other manufacturer's connections may be of similar construction and therefore subject to c.his failure mode.
On May 1, 1980, Pratt Company sent letters to their customers who have these connections (enclosed list). They recommended that their customers review their installation of such connections, and if the keyway is oriented below horizontal, make one of the following field modifications:
1.
Add a spacer bushing, or shim plate to fill the void between the top of the shaft and the indicating plate on the actuator.
2.
Locally upset the end of the valve shaft in the area sf the keyway using a hand punch in such a way that the key could not work loose.
3.
Install new keys of longer length which extend above the end of the valve shaft whereby the key is up to the actuator plate and could not slip down if inverted.
Recommended Action for Licensee Cons'E s
MENT We request that all plants make the connections similar to the above des not supplied by those particular man Entire document previously entered into system under:
are susceptible to failure, one of h Q[CC((
appropriate action should be taken t ANO l
No. of pages:
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