Protecting People and the EnvironmentUNITED STATES NUCLEAR REGULATORY COMMISSION
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 ***
