View source for Information Notice 1993-42, Failure of Anti-Rotation Keys in Motor-Operated Valves Manufactured by Yelan

{{Adams
| number = ML031070501
| issue date = 06/09/1993
| title = Failure of Anti-Rotation Keys in Motor-Operated Valves Manufactured by Yelan
| author name = Grimes B
| author affiliation = NRC/NRR
| addressee name = 
| addressee affiliation = 
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| license number = 
| contact person = 
| document report number = IN-93-042, NUDOCS 9306030147
| document type = NRC Information Notice
| page count = 12
}}
{{#Wiki_filter:"-
                                   UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555 June 9, 1993 NRC INFORMATION NOTICE 93-42:     FAILURE OF ANTI-ROTATION KEYS IN MOTOR-OPERATED

VALVES MANUFACTURED BY VELAN

==Addressees==
All holders of operating licenses or construction permits for nuclear power

reactors.

==Purpose==
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information       of

notice to alert addressees to potential problems resulting from the failure

anti-rotation keys in motor-operated globe valves manufactured by Velan forValve

Corporation. It is expected that recipients will review the information to

applicability to their facilities and consider actions, as appropriate, avoid similar problems. However, suggestions contained in this information  or

notice do not constitute NRC requirements; therefore, no specific action

written response is required.

==Description of Circumstances==
On March 28, 1993, Wisconsin Public Service Corporation, the licensee for

Kewaunee Nuclear Power Plant, reported that during motor-operated valve (MOV)
dynamic testing on March 27, 1993, one of two redundant safety injection

recirculation valves to the refueling water storage tank failed to close

completely. Investigation revealed that the anti-rotation device, an L-shaped

key between the valve stem and the yoke bushing (Attachment 1), had broken.

The shorter part of the broken L-shaped key had apparently worked its way The

toward the valve stem and had jammed the valve stem, preventing closing.

valve that failed was a 2-inch bonnetless globe valve manufactured by Velan and

Valve Corp. The licensee inspected all nine similar motor-operated valves and

found that six had broken anti-rotation keys. The inspections were visual can

did not require disassembly of the motor-operated valve. Failures usually

be observed on normally closed valves, since the broken long leg of the

L-shaped key slides down partially and becomes visible below the yoke bushing.

According to the licensee, the keys failed in a brittle manner. The fractures

began on either side of the key at the sharp radius of the inside corner of

the L-shaped key and propagated into the body of the key. Machining of the

sharp inside corner of the L-shaped key may have contributed to the failure of

the anti-rotation keys by producing high stresses in the corner of the keys.

It is likely that the rotational action of the valve stem impacted on both

sides of the key, exceeding the impact strength of the material at the sharp

radius of the key.

9306030147        POR SIE Wr;c-c 913o0&i                              93o0wt

41       'C1301q3                       in     le- //                 A

IN 93-42 June 9, 1993 In 1990, at the Maine Yankee Atomic Power Station, anti-rotation

4-inch MOVs manufactured by Velan failed. Maine Yankee                      keys in

the licensee, discovered that spare keys supplied by          Atomic     Power    Company, valves were not of the proper hardness; they were RockwellVelan    for   several     of the

harder Rockwell C-59 as originally specified. Valves               C-20   instead     of the

wrong anti-rotation keys installed were disassembled,      that    may   have   had   the

replaced the Rockwell C-20 keys with keys made of the and the licensee

non-conforming keys that were removed showed signs         correct material. The

During post-maintenance testing, several of the new   of   significant wear.

the corner of the 'L" shape. This happened because      (hardened)       keys broke at

the

adaptor plate was too tight considering the service-related   keyway     in the valve

occurred to the rest of the keyway. Maine Yankee engineers          wear   that had

larger keyways should be cut in the adaptor plate to                specified      that new

breaking when the valve is actuated. The licensee         prevent     the   key   from

valves and then tested the valves to ensure that they repaired all the affected

operated satisfactorily.

Before testing MOYs at Prairie Island this past winter, globe valves also discovered anti-rotation key failures an inspection of Velan

in 16 valves) in similar systems. Because of the              (2 broken keys found

location of the break on the

anti-rotation key, and the length of the key and key

Power Company, the licensee, believed that the broken slot, Northern States

still perform their intended function and that the         anti-rotation keys would

short leg of the L-shaped key) would not interact     broken     piece (i.e., the

impede valve operation. This is at variance with    with     the   valve stem so as to

above. The licensee added a step to their generic   the    Kewaunee      event discussed

procedure to inspect, clean, debur, and lubricate     actuator      replacement

anti-rotation devices.

Discussion

On April 5, 1993, Velan issued the attached (Attachment

#SB-106. This bulletin recommends that the anti-rotation2) Service Bulletin

for possible wear which could result in failure and               keys be inspected

given to replacing the keys at the earliest convenient  that    consideration        be

keys, which have been supplied by Velan for the              time.      The  replacement

past 24 years, are made of

material meeting American Iron and Steel Institute

opposed to 440C stainless steel (440C SS). AISI       (AISI) 4140 alloy steel, as

4140 is significantly tougher

than 440C SS. According to Velan, the material was

4140 is easier to procure and to heat treat properly.   changed to 4140 because

this bulletin to all U.S. nuclear utilities. On               Velan plans to send

between the NRC staff and Velan subsequent to the   the   basis     of conversations

and because of the hardness of anti-rotation keys    issuance       of  the bulletin, made

suggests that both the keys and the keyways be inspected     out    of  440C   SS, Velan

deterioration. The experience cited above indicates             for    damage    and

material in anti-rotation keys can lead to failures,      that    the   use   of  brittle

may not always be impaired.                               although      valve   operation

_     a

IN 93-42 June 9, 1993 This information notice requires no specific action or written response. If

you have any questions about the information in this notice, please contact

the technical contact listed below or the appropriate Office of Nuclear

Reactor Regulation (NRR) project manager.

Brian K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

Technical contact:  David C. Fischer, NRR

(301) 504-2728 Attachments: ('                       w      )
1. Figure 1, Velan Valve and Anti-Rotation Key

2. Velan Service Bulletin #SB-106
3. List of Recently Issued NRC Information Notices

N-
                                               Attachment 1 IN 93-42 June 9, 1993 VELAN VALVE AND ANTI-ROTATION KEY

STEM,
         11/X_ 5 ACME-2G-L.H.

PITCH: .200
         LEAD: .200                                       BUSHING

KEYWAY

VALVE.,
                            BUSHING

STEM

Attachment 2
                                     -_                    IN 93-42 June 9, 1993 _,VEAS

- SERVICE BUlll              ~-                I#SB-1 i

SUBJECT:-GLOBE VALVE STEM ANTROAIIO          KEY

This is to advise you that an "LI shaped, globe valve stem anti- rotation key failed at Kewaunee Nuclear Plant. The valve in question

is a 2; Motor operated globe valve originally supplied to drawing

137.116/1.

The valves affected are those Motor Operated Globe valves requiring a

key installed in mounting flange which prevents the stem from

rotating. Globe valves which have been supplied with torque arms are

not affected by this failure.

Based on the incident at Kewaunee Nuclear Plant we recommend that keys

be inspected for possible wear which could result in failure.

Consideration should also be given to replacing keys at your earliest

possible convenience with new keys.        These new keys are supplied in

material meeting AISI 4140. This material replaces the 440C grade

which several project drawings call up.

Replacement keys which have been supplied by us during the last 2 1/2 years have been from this new material. If these have been installed, only regular periodic verification will be required. If no inspection

and or replacements has been made, we recommend that key. be replaced.

For additional information or replacement keys, please contact:
                           Velan valve Corp.

550 McArthur

Montreal, Quebec

H4T 1X8 Attn t Nuclear Division

Phone: 514-748-7743 Pax s 514-342-2311 Nilaeon

Ic -  esident, Quality Assurance               Manager, nuclear Division

-       p--v..

pa--.

1  of 1  I

0
I'Tiril 5f 1993    By

l

My:   .I. Francois

3.1. Francois  Ilew      0o         1"..    1 of 1 I

'-I

Attachment 3 IN 93-42 June 9, 1993 Page l'of I

LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

Information                                   Date of

Notice No.             Subject                 Issuance    Issued to

93-41          One Hour Fire Endurance        05/28/93     All holders of OLs or CPs

Test Results for Thermal                    for nuclear power reactors.

Ceramics Kaowool, 3M

Company FS-195 and

3M Company Interam E-50
                Barrier Systems

93-40          Fire Endurance Test            05/26/93    All holders of OLs or CPs

Results for Thermal                         for nuclear power reactors.

Ceramics FP-60 Fire

Barrier Material

93-39          Radiation Beams from           05/25/93    All holders of OLs or CPs

Power Reactor Biolog-                       for nuclear power reactors.

ical Shields

93-38          Inadequate Testing of          05/24/93    All holders of OLs or CPs

Engineered Safety                          for nuclear power reactors.

Features Actuation

System

93-37          Eyebolts with Indeter-         05/19/93    All holders of OLs or CPs

minate Properties In-                       for nuclear power reactors.

stalled in Limitorque

Valve Operator Housing

Covers

93-36          Notifications, Reports,         05/07/93    All U.S. Nuclear Regulatory

and Records of Misadmin-                    Commission medical

istrations                                  licensees.

93-35          Insights from Common-           05/12/93    All holders of OLs or CPs

Cause Failure Events                        for nuclear power plants

(NPPs).

93-34,         Potential for Loss of           05/06/93    All holders of OLs or CPs

Supp. 1        Emergency Cooling                           for nuclear power reactors.

Function Due to A

Combination of

Operational and Post- Loca Debris in Contain- ment

OL = Operating License

CP = Construction Permit

IN 93-42 June 9, 1993 This information notice requires no specific action or written response. If

you have any questions about the information in this notice, please contact

the technical contact listed below or the appropriate Office of Nuclear

Reactor Regulation (NRR) project manager.

Original signed by

Brian K. Grimes

Brian K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

Technical contact:   David C. Fischer, NRR

(301) 504-2728 Attachments:
1. Figure 1, Velan Valve and Anti-Rotation Key

2. Velan Service Bulletin #SB-106
3. List of Recently Issued NRC Information Notices

*See previous concurrence sheet

*EMEB:DE:NRR      *SC/EMEB:DE:NRR    *RPB:ADM               *C/EMEB:DE:NRR

DCFischer         EJSullivan         TechEd                 JANorberg

4/15/93           4/16/93            4/15/93                4/19/93 I0
*C/EMCB:DE:NRR    *C/RVIB:DRIL       *DRS:RIII              *D/DE:NRR

JRStrosnider      LJNorrholm         GCWright               JERichardson

4/20/93           4/20/93            4/21J.3                4/23/93
*OGCB:DORS:NRR    *C/OGCB:DORS:NRR

RJKiessel         GHMarcus

05/03/93          05/12/93            II /93 DOCUMENT NAME:  93-42.IN

IN 93-XX

April 22, 1993 Even though a broken anti-rotation key does not always impair valve operation, it is a concern to the NRC that anti-rotation keys made of such brittle

material (440C SS) are used in safety-related valves.

This information notice requires no specific action or written response. If

you have any questions about the information in this notice, please contact

the technical contact listed below or the appropriate Office of Nuclear

Reactor Regulation (NRR) project manager.

Brian K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

Technical contact:     David C. Fischer, NRR

(301) 504-2728 Attachments:
       1.     Figure 1, Velan Valve and Anti-Rotation Key

2.     Velan Service Bulletin #SB-106
       3.     List of Recently Issued NRC Information Notices

Document Name:
       *See previous concurrence sheet

*EMEB:DE:NRR       *SC/EMEB:DE:NRR    *RPB:ADM          *C/EMEB:DE:NRR

DCFischer          EJSullivan         TechEd            JANorberg

4/15/93             4/16/93            4/15/93          4/19/93
*C/EMCB:DE:NRR     *C/RVIB:DRIL        *DRS:RIII        *D/DE:NRR

JRStrosnider       LJNorrholm          GCWright         JERichardson

4/20/93             4/20/93            4/21/93          4/23/93 OGCB:DORS:NRR      C/OGCB:DORS:NRR     D/DORS:NRR r

RJKiessel          GHMarcusHkiM        BKGrimes -
   / /93             f /taL/93            / /93 u

IN 93-XX

April 22, 1993 Even though a broken anti-rotation key does not always impair valve operation, it is a concern to the NRC that anti-rotation keys 'made of such brittle

material (440C SS) are used in so many safety-related valves.

This information notice requires no specific action or written response. If

you have any questions about the information in this notice, please contact

the technical contact listed below or the appropriate Office of Nuclear

Reactor Regulation (NRR) project manager.

Brian K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

Technical contact:   David C. Fischer, NRR

(301) 504-2728 Attachments:
      1.     Figure 1, Velan Valve and Anti-Rotation Key

2.     Velan Service Bulletin #SB-106
      3.     List of Recently Issued NRC Information Notices

Document Name:
      *See previous concurrence sheet

*EMEB:DE:NRR       *SC/EMEB:DE:NRR    *RPB:ADM          *C/EMEB:DE:NRR

DCFischer          EJSullivan         TechEd            JANorberg

4/15/93            4/16/93            4/15/93           4/19/93
*C/EMCB:DE:NRR     *C/RVIB:DRIL       *DRS:RIII         *D/DE:NRR

JRStrosnider       LJNorrholm         GCWright          JERichardson

4/20/93            4/20/93            4/21/93           4/23/93 OGCB:DORS:NRR      C/OGCB:DORS:NRR    D/DORS:NRR

===RJKiessel          GHMarcus           BKGrimes===
  / /93              / /93              / /93

IN 93-XX

114r    -Paige3,   1993 hardness of anti-rotation keys made out of 440C SS, Velan suggests that both

the keys and the keyways be inspected for damage and deterioration.

Even though a broken anti-rotation key does not always impair valve operation, it is a concern to the NRC that anti-rotation keys made of such brittle

material (440C SS) are used in so many safety-related valves.

This information notice requires no specific action or written response. If

you have any questions about the information in this notice, please contact

the technical contact listed below or the appropriate Office of Nuclear

Reactor Regulation (NRR) project manager.

Brian K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

Technical contact:   David C. Fischer, NRR

(301) 504-2728 Attachments:
       1.    Figure 1, Velan Valve and Anti-Rotation Key

2.     Velan Service Bulletin #SB-106
      3.     List of Recently Issued NRC Information Notices

Document Name:
      *See previous concurrence sheet

*EMEB:DE:NRR       *SC/EMEB:DE:NRR   *RPB:ADM          *C/EMEB:DE:NRR

DCFischer          EJSullivan        TechEd            JANorberg

4/15/93            4/16/93           4/15/93           4/19/93
*C/EMCB:DE:NRR     *C/RVIB:DRIL      *DRS:RIII         *D/DE:NRR

JRStrosnider       LJNorrholm        GCWright          JERichardson

4/20/93            4/20/93           4/21/93           4/23/93 OGCB:DORS:NRR4,    C/OGCB:DORS:NRR   D/DORS:NRR

===RJKiessel          GHMarcus          BKGrimes===
g/gJ/93 MQ<          / /93             / /93

Document Name:G:\FISCHER\VELAN.IN  CDoo  t1-1 1I.c"641 Ott FRv

EMEB:DE:NRR    8         :NRR        RPB:ADM                  C:& rgRR

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RJKiessel           GHMarcus                  BKGrimes

/ /93                 / /93                       / /93}}

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