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Home NRC Library Document Collections Events, Reports Associated with Part 21 Reports 1997

Part 21 Report - 1997-361

 
 


ACCESSION #: 9705120050



                                   AUTOMATIC VALVE

                         41144 vincent Court      Novi MI USA 48375-1924

                     Internet Address          www.automaticvalve.com

               Telephone 810.474.6700        Facsimile 810.474.6732

          World Class Air Valves and Controls



To: JOHN MACKINNON                 From: TODD HUTCHINS



Company NRC                        Date & Time: 5/2/97 3:34:09 PM



Fax number: +1 (301)816.5151       Pages: 5



Subject: 10CFR21 NOTIFICATION



GOOD AFTERNOON:



ATTACHED IS OUR 10CFR21 NOTIFICATION AND CORRECTIVE ACTION PER OUR

DISCUSSION/MESSAGE.  WE APOLOGIZE FOR THE TROUBLE AND

INCONVENIENCE THIS

MAY CAUSE.



IF YOU REQUIRE ADDITIONAL INFORMATION, PLEASE CONTACT ME.



BEST REGARDS, TODD.



DATE: May 2, 1997



SUBJECT: 10CFR21 NOTIFICATION OF POTENTIAL DEFECT



Addressees: All users of safety related solenoid valves manufactured by

Automatic Valve (AV) incorporating AC solenoids.



Purpose: AV is issuing this information notification to alert addressees

of the potential for degraded performance and/or life expectancy of their

AC solenoid valves if they exhibit a buzzing instead of humming sound

when energized.



Definitions: BUZZ - any audible metallic clicking sound or sound greater

in frequency and intensity than a hum.  HUM - sound similar in frequency

and intensity to florescent lights from an approximate 3 foot distance in

a general office noise environment.



Background: After installation of 89 AC solenoid valves by Vermont Yankee

(VY) in September 1996, BC Current of VY advised Todd Hutchins of AV that

5 valves made noise when energized (#06-11 louder than the rest).  AV

assumed this noise to be normal AC hum since no known product or customer

complaint failure had ever been received by AV due to AC hum or buzz.

Because of the preceding assumption and facts, AV took no action at that

time.  All AC solenoids hum to some extent.



April 24, 1997 VY obtained scram times during an auto scram of their

plant.  These scram times averaged identically to the original 1996

times.  However, valve #06-11 took approximately.246 seconds (5 times)

longer.



April 25, 1997 VY sent AV valve #06-11 for a failure analysis and

visually inspected the internal components of any buzzing solenoids (VY

event report #97-0424).



April 28, 1997 AV issued VY an initial root cause report (#2531 attached)

and shipped replacement solenoid parts that had been 'noise' tested.

Definitions of noise were developed based on VY experience and AV

analysis of returns.



After interviews with AV inspection personnel, it was clear that valves

at AV had been inspected for 'noise' but this had been done unofficially

without any consistent acceptance/rejection criteria.  Dimensional

differences between solenoids that buzz and hum are not detectable.  This

was confirmed with 2 solenoid valve competitors.  Definitions for

acceptable AC hum and rejectable buzz for AC solenoids have now been

added to inprocess inspection points and final test procedures at AV.



Recommendation: Even though the solenoid valve functioned, it was

significantly slower due to the amount of metallic by-product from the

buzzing solenoid plunger.  Regardless of the manufacturer, solenoids

should be checked for buzzing noises as it could degrade the performance

and potentially the life of the valve.  Any rebuilding of anyone's

solenoid valves should require a 'noise' test.  Since 1970 AV has not

been advised of a single safety related AV product failure due to this

cause.  VY confirmed this with their check of the NPRDS.



AV will retest, recertify, and reship at no charge any suspect product.

AV will replace and reship at no charge any component found to be field

defective.



This information intends to fulfill Automatic Valve's obligation under

10CFR21 and is being sent with all attachments to all known customers who

have purchased AC solenoid valves with 10CFR21 imposed on their purchase

order.



Should you have any additional questions, please feel free to contact me.



Very truly yours,

AUTOMATIC VALVE CORPORATION



Todd Hutchins

President



REQUIREMENTS:



NUMBER: CORRECTIVE ACTION #2531



Type of Problem: Part B7122-145    [] Procedure        Date: 04-25-1997



Who found Problem: [] AV   [] Supplier  [] Distributor      Customer

Company: VERMONT YANKEE (VY)       Contact Name: BC Current

Address:                           Phone: 802-258-5457  Fax: 802-258-5544



1. Team Working on Problem: Leader: D. S. Swinton

     T. TROY                                 Members: K. W. Armstrong,



2. Describe Problem (initial Concern and Symptoms): The plunger on

     solenoid number 1 failed to return to it's de-actuated position in a

     timely manner when the solenoid was de-energized.  As a consequence,

     air exhausted from the piston in the main valve slower than normal

     (reference VY event report #97-0424).  Upon examination, the top of

     the solenoid plunger was found to be severely worn and had formed a

     peened edge around the top of the plunger.  This edge interfered

     with the plunger guide and caused the plunger to drag.  The customer

     reported very loud buzzing of this solenoid at original

     installation.



     Initial examination of the valve also revealed black dust.

     Laboratory analysis of this dust confirmed it to be 400 series

     stainless steel - the same material from which the plunger is

     constructed.



     Acknowledged by: K. W. Armstrong   Title: VP Quality Systems



                                                         Date: 04-27-1997



3. Contain Symptom (Action): Verify that existing valves are free of

     buzzing (metallic clicking as opposed to 60 cycle hum) by testing

     the plunger in a minimum of 8 positions and leaving the solenoid

     energized for a minimum of 4 hours.  Replace the plunger guide,

     spring, and plunger on all units that exhibit any buzzing (shipped

     4-28 and 4-29).



     Similar units have been in commercial use for over 40 years and

     identical units used for utility service for over 27 years and this

     is the first reported or known incidence of such a condition due to

     the solenoid being continuously energized.



     Approved by: K. W. Armstrong   Title: VP Quality Systems



                                      Est. Date:      Act Date: 4-27-1997



4. Root Cause/s of Problem: (initial assessment)

     Loud audible buzzing of the solenoid indicates that the solenoid

     plunger was moving while in the energized condition and that this

     movement caused premature and severe wear of the plunger.



Approved by: K. W. Armstrong  Title: VP Quality Systems



                                     Est. Date:       Act Date: 4-27-1997



5. Corrective Action:

     Since dimensional inspection cannot differentiate solenoids that

     buzz vs hum, add 'noise' test at in-process and final inspection

     points as part of material dedication process.



     Test Conducted to Verify It: VY event report #97-0424 indicates

     solenoid noise remained consistent for 6 months.  AV added

     additional 4 hour burn-in test to replacement units for VY with no

     change in noise.



     Approved by: K. Armstrong     Title: VP Quality Systems



                                       Est. Date:     Act. Date: 05-01-97



6. Implementation (Describe and Include Applicable CN Numbers):

     Added noise test to AC solenoid prints for in-process control and to

     final inspection procedure (CN #7413).



     Approved by: K. Armstrong     Title: VP Quality Systems



                                        Est. Date:    Act. Date: 05-01-97



7. Corrective Action to System to Prevent Recurrence:

     Not yet assessed.



     Approved by:        Title     Est. Date: 05-30-97 Act. Date:



8. Verification (Describe):



     Approved by:        Title:    Est. Date:          Act. Date:



GENERAL INFORMATION or OTHER            EVENT NUMBER: 32253



LICENSEE: AUTOMATIC VALVES CORPORATION  NOTIFICATION DATE:  05/01/97

CITY:     NOVI           REGION: 3      NOTIFICATION TIME:  16:14 [ET]

COUNTY:                  STATE: MI      EVENT DATE:         04/25/97

LICENSE#:                AGREEMENT: N   EVENT TIME:         00:00[EDT]

DOCKET:                                 LAST UPDATE DATE:   05/02/97



                                             NOTIFICATIONS



                                        KATHLEEN DOLCE (R1) RDO

                                        DICK WESSMAN        EO

NRC NOTIFIED BY: TODD HUTCHINS          MARK RING (R3)      RDO

HQ OPS OFFICER: JOHN MacKINNON          VERN HODGE (RVIB)   NRR

                                        AL CHAFFEE          NRR

EMERGENCY CLASS: NOT APPLICABLE         RICH BARRETT        IRD

10 CFR SECTION:

CCCC 21.21          UNSPECIFIED PARAGRAPH



                               EVENT TEXT



PART 21 REPORT REGARDING FAILURE OF SCRAM SOLENOID PILOT VALVES

ISSUED BY

AUTOMATIC VALVES CORPORATION, NOVI, MICHIGAN.



IN SEPTEMBER, 1996, AUTOMATIC VALVES CORPORATION (AVCO) WAS NOTIFIED

BY

VERMONT YANKEE THAT A SCRAM SOLENOID PILOT VALVE WAS MAKING A

BUZZING

SOUND (RATHER THAN A HUMMING SOUND) WHEN ENERGIZED.  AVCO

DISCOUNTED THE

REPORT AND TOOK NO ACTION AT THAT TIME BECAUSE ALL AC SOLENOIDS

HUM TO

SOME EXTENT AND THEY ASSUMED THIS NOISE TO BE A NORMAL AC HUM SINCE

NO

KNOWN PRODUCT OR CUSTOMER COMPLAINT FAILURE HAD EVER BEEN

RECEIVED BY

AVCO DUE TO AC HUM OR BUZZ.



ON 04/24/97, WHILE VERMONT YANKEE WAS PERFORMING SCRAM TIME TESTING,

THE

CONTROL ROD ASSOCIATED WITH THE NOISY SCRAM SOLENOID PILOT VALVE

#06-11-

118 (WHICH HAD BEEN NOISY FOR THE LAST SIX MONTHS) HAD A SCRAM TIME

THAT

WAS SLOWER THAN THE OTHER CONTROL RODS THAT WERE BEING TESTED,

BUT WAS

WITHIN THE TECHNICAL SPECIFICATION TIME LIMITS.



AVCO HAS DETERMINED THAT THE NOISE WAS DUE TO METALLIC VIBRATION

WITHIN

THE SCRAM SOLENOID PILOT VALVE WHICH CAUSED THE VALVE PERFORMANCE

TO

DEGRADE.  DURING PAST ACCEPTANCE TESTS, AVCO DID NOT USE AUDIBLE

NOISE

EMANATING FROM THE SCRAM SOLENOID PILOT VALVES AS AN ACCEPTANCE

CRITERION.  AVCO HAS CHANGED THEIR PROCEDURES TO USE THIS CRITERION.

AVCO HAS SUPPLIED SCRAM SOLENOID PILOT VALVES TO 20 - 25 NUCLEAR

POWER

PLANTS IN THE UNITED STATES.



***UPDATE AT 1640 ON 05/02/97 BY AVCO TODD HUTCHINS TAKEN BY

MacKINNON***



AFTER INTERVIEWS WITH AVCO INSPECTION PERSONNEL, AVCO MANAGEMENT

PERSONNEL DETERMINED THAT VALVES AT AVCO HAD BEEN INSPECTED FOR

"NOISE"

BUT THIS HAD



                        (Continued on next page)



LICENSEE: AUTOMATIC VALVES COR            PAGE # 2 OF EVENT NUMBER: 32253



BEEN DONE UNOFFICIALLY WITHOUT ANY CONSISTENT

ACCEPTANCE/REJECTION

CRITERIA.  DIMENSIONAL DIFFERENCES BETWEEN SOLENOIDS THAT BUZZ AND

HUM

ARE NOT DETECTABLE.  THIS WAS CONFIRMED WITH TWO AVCO SOLENOID

VALVE

COMPETITORS.  DEFINITIONS FOR ACCEPTABLE AC HUM AND REJECTABLE BUZZ

FOR

AC SOLENOIDS HAVE NOW BEEN ADDED TO IN-PROCESS INSPECTION POINTS

AND

FINAL TEST PROCEDURES AT AVCO.



AVCO RECOMMENDATION: EVEN THOUGH THE SOLENOID VALVE FUNCTIONED,

IT WAS

SIGNIFICANTLY SLOWER DUE TO THE AMOUNT OF METALLIC BY-PRODUCT

FROM THE

BUZZING SOLENOID PLUNGER.  REGARDLESS OF THE MANUFACTURER,

SOLENOIDS

SHOULD BE CHECKED FOR BUZZING NOISES AS IT COULD DEGRADE THE

PERFORMANCE

AND POTENTIALLY THE LIFE OF THE VALVE.  ANY REBUILDING OF ANY

SUPPLIER'S

SOLENOID VALVES REQUIRE A 'NOISE" TEST.  SINCE 1970, AVCO HAS NOT BEEN

ADVISED OF A SINGLE SAFETY RELATED AVCO PRODUCT FAILURE DUE TO THIS

CAUSE.  VERMONT YANKEE CONFIRMED THIS WITH A CHECK OF THE NUCLEAR

PLANT

RELIABILITY DATA SYSTEM.



AVCO WILL RETEST, RECERTIFY, AND RESHIP AT NO CHARGE ANY SUSPECTED

PRODUCT.  AVCO WILL REPLACE AND RESHIP AT NO CHARGE ANY COMPONENT

FOUND

TO BE FIELD DEFECTIVE.



THE OPERATIONS OFFICER NOTIFIED R1DO (MICHAEL MODES), R2DO (CHUCK

CASTO),

R3DO (MARK RING), R4DO (JOE TAPIA) & NRR VERN HODGE.



*** END OF DOCUMENT ***

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