ML17261B233
| ML17261B233 | |
| Person / Time | |
|---|---|
| Issue date: | 04/14/1978 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| To: | |
| References | |
| IEB-78-05, IEB-78-5, NUDOCS 7910010658 | |
| Download: ML17261B233 (14) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.
C.
20555 IE Bulletin No. 78-05 Date:
April 14, 1978 Page 1 of 2 MALFUNCTIONING OF CIRCUIT BREAKER AUXILIARY CONTACT MECHANISM - GENERAL ELECTRIC MODEL CR105X Description of Ci r cumstances:
The Sacramento Municipal Utility District recently reported a problem encountered with the operation of the GE Model CR105X auxiliary contact mechanism installed in a 480 volt circuit breaker.
Investigation into the cause for the inability to shutdown a booster supply fan (SF-A-7) in the control room emergency air conditioning system revealed that an auxiliary contact (GE Model CR105X) had failed in the closed position, preventing the fan's power supply circuit breaker from opening.
The specific cause for failure was binding of the plunger arm due to burrs and nicks on its surface.
An investigation was conducted by the licensee to determine the extent of usage of this type auxiliary contact in other circuits throughout the reactor power plant.
Approximately fifty (50) positions in the nuclear service motor control centers were identified as having a similar type auxiliary contact mechanism.
It was also determined that many of the affected systems which require contact operation similar to that described above, either permit or provide a safety feature function during emer-gency conditions.
An example of this type application is auxiliary contacts that must open to permit closing of certain safety related valves from 480 volt motor control centers.
The attached GE Service Advice Letter and associated instruction/drawing sheet were sent to all nuclear power reactor facilities by GE Field Service Offices.
The letter, together with the instruction/drawing sheet identifies the problem and provides the recommended corrective action.
qE
IE Bulletin No. 78-05 Date:
April 14, 1978 Page 2 of 2 Action To Be Taken By Licensees and Permit Holders:
For all power reactor facilities with an operating license or construc-tion permit:
l.
If you have received the enclosed General Electric letter and instruction/drawing sheet addressing the auxiliary contact mech-anism problem, and if you have these devices in use at your facility, it is requested'hat you describe what corrective action you have taken.
2.
If you have not received the enclosed GE documents before, it is requested that you describe what action you plan to take if the GE CR105X auxiliary contact mechanism is in use or planned for use in safety systems at your facility(ies).
3.
Facilities having an operating license should report in writing, within 45 days, and facilities with construction permits within 60
- days, the results of action taken or planned with regard to Items 1
and 2 above.
Your written reply should also include the date when such actions were or will be completed.
Reports should be sub-mitted to the Director of the appropriate NRC Regional office and a
copy should be forwarded to the U. S. Nuclear Regulatory Commission, Office of Inspection and Enforcement, Division of Reactor Operations Inspection, Office of Inspection and Enforcement, Mashington, D. C.
20555.
Approved by GAO, 8180225 (R0072); clearance expires 7/31/80.
Approval was given under a blanket clearance specifically for identified generic problems.
Attachments:
1.
GE Letter 2.
GE Control and Instruction Sheet
lN STRU CTt ONS LQSX AUXILIARYCONTACT (CHANGiOUTOF PL.UNGER ARMAND INSULATION) for nema size 0 8 1 magnetic starters and contactors REMOVING OVERLOADRELAYBRACKET(SE Ff 1) 1.
Rcmove all cfcctricaf power fram device.
2.
Olsxsscmbfe device by pressing on the coil while pulling out an
'he cail retainers.
Move retainers back and away from caiL 3.
Grasp movable portion af magnet and pull out. removing magnet asscmbiy. coil, molded cover and inovable arm in one inotian.
{HOTrt On revcrscrs or multispced starters, this magnet asscinbly is linked to the mechanical interlock arm between cantactars and should be tipped toward interlock anti ta facilitate easy fcmovaL) 4.
Rcmove avcrfaxd relay bracket by sliding'lt out of the keyed sets m the molded base.
(NOTE: lf any wires are toa short to chaw easy renmaL temporarily disconnect these.)
S.
Rcmove overload relay from bracket by loosening screw on bottom of overload brackeL V.4~Pe OVERLQAO RELAYsiCXWrlHC SRACKET -'
4(
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CHANGING PLUNGER ARM 4 INSULATION(SEE FfG 2)
Slide plunger assembly out of auxiliary contact block. by lifting upend out.
2.
Select the new plunger arm that is bent the someway as the onc insta fle(L 3.
Loosen screw an plunger ta release metal arm but OO HOT REMOVE SCRHV FROM PHENOL]C PLVNGER (OR PLUNGERS).
4.
Mount new plunger arin on plunger, Fasten arm to plunger with screw (ar plunger pa !ifinstalling double aux. blocks).
5.
Applythin caat ot acrashell gmase along plunger guides.
6.
Reinstall plunger assembly incontact block.
7.
Reassemble overload to mounting bracket.
Remove aver{cad
~ fnsulation and install new. (NOTE: Overload msulation must be rcmaved and replaced with new insula tian su pplicd withkit) 8.
Remount complete aSSenibly on cantactor base.
I 9.
Reconnect any wires prcviausly rcmove(L 1(L Reassemble magnet assemofy ta contact base (on revcrscrs or multis~ be sure to interiack this asMmbfy with mcchxnicaf interlock arm. Check lortree movement of armature asscmblics and macha nica',inter focks).
11.
Observe that auxiliary contact plunger assemblies are cycrating properly'aiL RETAIHEfCS
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It has been brought to our attention that a potential binding problem may exist with the 1QQ Line CR105X... auxiliary interlocks mounted on HENA size 00, 0 and 1 cortactors, starters, or reversers used in control equipment manufactured by General Electric Co. (including 7700 Line motor control centers) and other control equipment manufacturers.
The interlocks involved are used on the following devices.
CR105A, -B., -C, -H, -J, -K, -R, -S with additional suffix letters and numbers (contactors)
CR106A, -B, -C, -H, -J, -K, -R, -S with additional suffix letters
.and numbers (starters)
CR109A, -B, -C. -H, -J, K, -R, -S with additional suffix letters and numbers (reversing starters)
If any of these devices are currently used in your installations, you should obtain replacement parts to correct this condition by forwarding the following information to my attention:
I l.
Complete catalog (CR) numbers on device nameplate.
2.
guantity of each device catalog number.
3.
Are the auxiliary interlocks mounted on the left side, right side, or both sides of the device?
How many are there at each location?
Since the General Purpose Control Department of the General Gectric Co.
does not know all applications of these interlocks,'t is assumed that some may he in "critical" applications and should be changed out as soon as possible, while those in non-critical applications ntay be changed out at some routine maintenance period.
Since these interlocks are on devices which have been in service for over one (1) year and are out of our normal warranty period, we feel a
fair and equitable solution would require that the necessary parts and instructions for the'uggesfed changeout be provided by Gt; at no expense to the user, At your earliest convenience, please provide me with the information requested in par agraph 2 of this letter so that the necessary parts may be provided.
This information should be forwarded to:
General Electric Company P. 0.
Box 2913 Bloomington, Illinois 61701 Attention:
Nr. John E. Corbitt Product Service (Dial Conn:
8 325-4416, or 4294)
Attachment 1
Page 1 of 1
ENCLOSURE 2
LISTING OF IE BULLETINS ISSUED IN 1978 IE Bulletin No. 78-05 April 14, 1978 Bulletin Subject No.
Date Issued Issued To 78-01 78-02 78-03 78-04 Flammable Contact-Arm Retainers in G.E.
CR120A Relays Terminal Block gualification Potential Explosive Gas Mixture Accumula-tions Associated with BWR Offgas System Operations Environmental qua 1 i-fication of Certain Stem Mounted Limit Switches Inside Reactor Containment I/16/78 I/30/78 2/8/78 2/21/78 All Power Reactor Facilities with an Operating License (OL) or Construc-tion Permit (CP)
All Power Reactor Facilities with an Operating License (OL) or Construc-tion Permit (CP)
All BWR Power Reactor Facilities with an Operating License (OL)
All Power Reactor Facilities with an Operating License (OL) or Construc-tion Permit (CP)
Page 1 of 1
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ROCHESTER GAS AND ELECTRIC CORPORATION I~,
~
S9 EAST AVENUE, ROCHESTER, M.Y. 146d9 I.EON D. WHITE. JR.
VICE PRESIDENT
'I C LC P H0 N C ar Ci COOC VIC 546-2700 March 3, 1978 Mr. Boyce H. Grier, Director U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement Region I 631 Park Avenue King of Prussia, Pennsylvania 19406
Subject:
IE Bulletin No 78-04, Environmental Qualification of Certain Stem Mounted Limit Switches Inside Containment,,
R. E. Ginna Nuclear Power Plant, Unit No.
1 Docket. No. 50-244
Dear Mr. Grier:
This letter is in response to IE Bulletin 78-04, requesting that we determine if the NAMCO D2400X or EA-170-302 SNAP LOCK stem mounted limited switches are utilized at our facility in any safety related application in primary containment.
A detailed review has been made of all safety related electrical equipment subject to severe environmental conditions during design basis events in response to the letter of December 23, 1977 from Victor Stello, Jr. regarding the level of environmental qualifica-tion of electrical equipment at, Ginna Station.
A report on this review was submitted on February 24, 1978.
In the course of this review all safety related valves subject to DBE effects were checked for the use of stem mounted limit switches and it was determined that, there are none at Ginna Station.
Very truly yours, L. D. Whi e, Jr.
P,IC REGS
+ Ci+
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4'ocket'No. 50-244 i
UNITED STATES NUCLEAR REGULATORY COMMISSION REGION I 631 PARK AVENUE ICING OF PRUSSIA, PENNSYLVANIA 19406 Febvuary 21, 1978
~+WC~ F(t.es Rochester Gas and Electric Corporation ATTN:
Nr. Leon D. White, Jr.
Yice President Electric and Steam Production 89 East Avenue Rochester, New York 14649 Gentlemen:
Enclosed is IE Bulletin No. 78-04 which requires action by you with regard to your power reactor facility(ies) having an operating license or a construction permit.
Should you have questions regarding. this Bulletin or the actions required, please contact this office.
Sincerely, Boyce vier Director
Enclosures:
l.
List of IE Bulletins Issued in 1978 cc w/encls:
L. S.
Lang, Plant Superintendent J.
W. Witte, gC Engineer Lex K. Larson, Esquire