ML19323F645
| ML19323F645 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 05/14/1980 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Mattimoe J SACRAMENTO MUNICIPAL UTILITY DISTRICT |
| References | |
| NUDOCS 8005290268 | |
| Download: ML19323F645 (1) | |
Text
,
f(C ps** P%,,o UNITED STATES
- g
[ *4 NUCLEAR REGULATORY COMMISSION 3.*'().n ff j
/,r e REGION V t
0,
[
' 1990 N. CALIFORNI A BOULEVARD b
%, ** U o
SulTE 202, WALNUT CREE K PLAZA
,,,o WALNUT CREE K, CALIFORNIA 94596 May 14, 1980 Docket No. 50-312 Sacramento Municipal Utility District P. O. Box 15830 j
Sacramento, California 95813 Attention: Mr. John J. Mattimoe Assistant General Manager Gentlemen:
The enclosed Circular No. 80-12, is forwarded to you for information.
If there are any questions related to your understanding of the suggested actions, 4
please contact this office.
Sincerely, h[
.~ G.*n R. H. Engelken Director
Enclosures:
1.
IE Circular No. 80-12 2.
l.ist of Recently Issued IE Circulars cc w/ enclosures:
R. J. Rodriguez, SMUD L. G. Schwieger, SMUD l
l l
i
SSIflS flo. : 6830 UllITED STATES Accession flo.:
flUCLEAR REGULATORY COMMISS10ft 8005050052 0FFICE OF IflSPECTI0fl AtlD EllFORCEMEflT WASHIflGT0fl. D.C.
20555
,k-Q / >AA a May 14, 1980
'[
IE Circular flo. 80-12 VALVE-SHAFT-TO-ACTUATOR KEY MAY FALL OUT OF PLACE WHEfl MOUflTED BELOW HORIZ0flTAL AXIE Description of Circumstances:
Tennessee Valley Authority has identified and reported to the flRC a nonconformance on a Bettis Robot-Arm actuator installed on a Pratt Butterfly Valve at the Sequoyah nuclear plant.
It is reported (ref. attacSed 10 CFR 50.55e 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 / actuator. We believe other manufacturer's connections may be of similar construction and therefore subject to this t
failure mode.
(
On May 1,1980, ?ratt Company sent letters to their customers who have these l
connections (enclosed list). They recommended that their customers review their installatiov of such connections, and if the keyway is oriented below horizontal, make ole of the following field modifications:
1.
Add a spacer bushing, or shim plate to fill the void between the top of the shaf t and the Mdicating plate on the actuator.
2.
Locally upset the end of the valve shaft in the area of 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.
i j
Recommended Action for Licensee Consideration:
We request that all plants make the above recont. ended inspection of all connections similar to the above described Bettis/Pratt connection, whether or not supplied by those particular manufacturers.
If connections are found that are susceptible to failure, one of the above recommended accions or other appropriate action should be taken to correct the potential problem.
No written response to this Circular is required.
If you desire additional information regarding this matter, contact the Director of the appropriate f!RC Regional Office.
L l
J i
ATTACHMENT 1 SEQU0YAH NUCLEAR PLANT UNITS 1 AND 2 NCR 19P 10 CFR 50.55(c)
REPORT NO. 1 (FINAL)
LOOSE KEY IN BETTIS ROBOT-ARM VALVE ACTUATORS i
Description of Condition A containment isolation valve in Unit 1 became inoperable when the key which locks the actuator to the valve shaft fell out of place. This problem could occur with Bettis Robot-Arm valve actuators (model numbers 732C-SR80, 721C-SR60, 521C-SR60, CB525-SR60) when installed upside down'or sideways. With the valve shaft mounted below horizontal, there is a potential for the key to work I
itself loose.
Safety Implications If the valve actuator were to fall out, it would result in a loss of valve control.
Since these valve actuators are on safety-related valves, this-condition could have adversely affected or reduced the redundancy of safety-related systems.
Corrective Action i
TVA has identified 51 suspect operators in the Purge Air System, Emergency Gas Treatment System and the Chilled Water System.
Those operators that are installed so that the key can work loose will have spacer bushings installed in the actuator as recommended by the vendor.
Installation of the spacer bushings will be completed before fuel loading. All TVA design project managers are being asked to ensure that this problem does not occur at other TVA nuclear plants.
t t
1
=w w4-
ATTACHMENT 2 LIST OF ADDRESSEES FOR MAY 1 LETTER FROM HENRY PRATT COMPANY Metropolitan Edison - Three Mile Island #2 i
Arkansas Power & Light Arkansas Nuclear One 1 i
Wisconsin Public Service - Pioneer Service Kewaunee Northern States Power - Prairie Island 1 & 2 3
Baltimore Gas & Electric - Calvert Cliffs 1 & 2 Florida Power Corporation - Crystal River #3 Florida Power & Light - St.
Lucie #1 & 2 Toledo Edison - Davis-Besse #1 Alabama Power Company - Joseph M. Farley 1 & 2 Tennessee Valley Authority - Sequoyah 1 & 2 4
Pennsylvania Power & Light - Susquehanna 1 & 2 Mississippi Power & Light - Grand Gulf 1 & 2 L
Cleveland Electric Illuminating Company - Perry 1 & 2 Commonwealth Edison Company - Zion 1 & 2 l
Rochester Gas & Electric - Robert E. Ginna 1 Westinghouse Hanford/FFTF Westinghouse - Phillipines Northeast Utilities - Millstone #3 Tennessee Valley Authority - Stride 1
f E
A
,.-..,n-
~
IE Circular flo. 80-12 Enclosure May 14, 1980 RECEllTLY ISSUED IE CIRCULARS Circular Subject Date of Issued to No.
Issue 80-11 Emergency Diesel Generator 5/13/80 All holders of a power Lube Oil Cooler Failures reactor CL or CP 80-10 Failure to Maintain 4/29/80 All holders of Reactor Environmental Qualification OLs and cps of Equipment 1
80-09 Problems With Plant Internal 4/28/80 All' holders of a power
)
Communications Systems reactor OL or CP j
1 80-08 BWR Technical Specification 4/13/80 All General Electric Inconsistency - RPS Response BWR's holding a power Time reactor OL 80-07 Problems with HPCI Turbine 4/3/80 All holders of a power 011 System reactor OL or CP i
80-06 Control and Accountability 4/14/80 Medical licensees in Systems for Implant Therapy Categories G and G1 Sources 80-05 Emergency Diesel-Generator 4/1/80 All holders of a power Lubricating 011 Addition and reactor OL or CP Onsite Supply 80-04 Securing of Threaded Locking 3/14/80 All holders of a power Devices on Safety-Related reactor OL or CP 4
Equipment 80-03 tection from Toxic Gas 3/6/80 All holders of a hazards power reactor OL 80-02 Nuclear Power Plant Staff 2/1/80 All holders of Reactor Work Hours Ols, including research and test reactors, and cps 80-01 Service Advice for GE 1/17/80
'icensees of Inductio1 Disc Relays nuc u r power reactor operat!ng facilities and holders of nuclear power reactor cps
._