United States Nuclear Regulatory Commission - Protecting People and the Environment

ACCESSION #:  9504110135

                                      Exhibit B          
                                      ENC-QE-40
                                      Revision 9
                                      Page 1 of 3
    
TO:       Nuclear Licensing Manager

Subject:  Part 21 Notification 9505-Regarding Automatic Switch Company
          (ASCO) Pilot Solenoid Valve Model # NP8323A20V

LaSalle Site Support Engineering has evaluated the subject document and
determined that the defect/noncompliance is reportable under the
requirements of 10CFR Part 21. The attached report has been prepared for
submittal to the NRC, and should be submitted by    to the NRC Operations
Center.

Questions regarding this report should be directed to William C. 
Kirchhoff x2927.

                                             NED Engineer


                                             NED Supt./Supervisor


                                             NED Manager

President and Chief Operating Officer
Senior Vice President, Nuclear Operations
Vice President BWR Operations
Vice President PWR Operations
Vice President Nuclear Engineering and Construction
General Manager Nuclear Services
General Manager Quality Programs and Assessments
Nuclear Station Managers
Nuclear Engineering Managers  
Safety Assessment Manager
Manager of Quality Assurance/Nuclear Safety
Part 21 Coordinator
ENC Regulatory Assurance Supervisor


                                                  Exhibit B
                                                  ENC-QE-40           
                                                  Revision 9
                                                  Page 2 of 3

10CFR 50 Part 21 Notification 
Deficiency of ASCO Dual Solenoid Valve Model # NP8323A20V, Manufactured
by the Automatic Switch Company and used at LaSalle County Station 
Part 21 file # 9505

* Applicability

This notification is submitted in accordance with the requirements of 
10CFR 21, Section 21.1(b), 21.3a(3), and 21.3d(4).

* Identification of Facility and Component

This defective component was identified only at Commonwealth Edison's
LaSalle County Station. The effected solenoid valves are used on Main
Steam Isolation Valves (MSIV) 1(2)B21-F022 A/B/C/D and 1(2)B21-F028
A/B/C/D as part of the actuating mechanism.

* Identification of Component Manufacturer

The ASCO Dual Solenoid Valve Model NP8323A20V is manufactured by the
Automatic Switch Company (ASCO). 

*Nature of Defect 

The ASCO Model # NP8323A20V valve is a dual coil, three-way solenoid
valve used at LaSalle as a pilot valve which controls the opening and
closing of the MSIVs. A root cause investigation has attributed two
recent failures of the MSIVs to close to the ASCO pilot solenoid valves. 
In particular, internal sticking of the "B" core assembly to the plugnut,
which prevented the valves from changing state.  It is believed that a
foreign material acted as an adhesive film. This substance was determined
to be Nyogel 775A grease.  It is unknown how the Nyogel 775A came to this
location. According to information provided by ASCO. Nyogel is used in
the valve. Entry of Nyogel 775A from sources external to the valve were
investigated and considered implausible.

* Safety Significance

Failure of the ASCO NP8323A20V pilot solenoid valve to shift position
when de-energized would prevent the automatic or manual fast closure of
the main steam isolation valves. The safety function of the MSIVs as
described in LaSalle's Technical Specification Basis Section 3.4.4.7 
Main Steam Line Isolation Valves describes the safety function as
minimizing potential leakage paths from the containment in case of a
steamline break to limit release of fission products and to ensure that
the core is not uncovered following line breaks. The MSIVs function is
also described in the Technical Specification Basis 3/4.6.3 Primary
Containment Isolation Valves to


                                             Exhibit B
                                             ENC-QE-40
                                             Revision 9
                                             Page 3 of 3

ensure that the containment atmosphere will be isolated from the outside
environment in the event of a release of radioactive material to the
containment atmosphere or pressurization of the containment.

*Time of Discovery

February 18, 1995

*Corrective Actions

Unit Two

*Outboard ASCO Pilot Solenoid valves have been replaced with Valcor 3-way
solenoid valves as had been previously scheduled for this current outage
(L2R06).

*Inboard ASCO Pilot Solenoid valves have been replaced with new ASCO
valves assembled without grease.

Unit One

*Engineering has performed an operability evaluation and recommended
increasing the testing frequency of the MSIV's to 60 days.  The cycling
of the valves is believed to break the cohesion (binding formation) which
decreases the sticking probability.  Operating has chosen a more
conservative testing frequency of 30 days.  

*LaSalle plans for next Unit One refueling outage include the replacement
of the inboard ASCO valves with new ASCO valves assembled without grease
and the replacement of the outboard ASCO valves with Valcor solenoid
valves.

*Number and Location of All Defective Components

The effected solenoid valves are used on Main Steam Isolation Valves
(MSIV) 1(2)B21-F022 A/B/C/D and 1(2)B21-F028 A/B/C/D.

*Technical Contracts

William C. Kirchhoff, LaSalle Site Support Engineering
Charles J. Bohan, LaSalle Site Support Engineering

Questions Pertaining to this notification should be addressed to:
     Eric Steckhan
     NETS Part 21 Coordinator
     Commonwealth Edison Company
     1400 Opus Place, Suite 400
     Downers Grove, IL 60515
     (708) 663-7437


                          PART 21 SUMMARY SHEET

In accordance with Part 21 you, as an officer of CECo, are being informed
of the following situation:

A defect in the ASCO NP8323A20V Dual Solenoid valve manufactured by the
Automatic Switch Company was identified.  These ASCO valves are used at
LaSalle as a pilot valve which controls the opening and closing of the
MSIV's.  A root cause investigation has attributed two recent failures of
the MSIVs to close to the ASCO pilot solenoid valves.  In particular,
internal sticking of the "B" core assembly to the plugnut, which
prevented the valves from changing state.  It is believed that this
foreign material acted as an adhesive film.  This substance was
determined to be Nyogel 775A grease, It is unknown how the Nyogel 775A
came to this location.  According to information provided by ASCO, Nyogel
is used in the valve.  Entry of Nyogel 775A from sources external to the
valve were investigated and considered implausible.

LaSalle is the only user in the CECo system that uses this model valve.
Failure of the ASCO NP8323A20V pilot solenoid valve to shift position
when de-energized would prevent the automatic or manual fast closure of
the main steam isolation valves

Corrective Actions:

Unit Two

*Outboard ASCO Pilot Solenoid valves have been replaced with Valcor 3-way
solenoid valves as had been previously scheduled for this current
refueling outage (L2R06).

*Inboard ASCO Pilot Solenoid valves have been replaced with new ASCO
valves assembled without grease.

Unit One

*Engineering has performed an operability evaluation and Operating has
increased the testing frequency of the MSIV's to every 30 days.  The
cycling of the valves is believed to break the cohesion (binding
formation) which decreases the sticking probability.

*LaSalle plans for next Unit One refueling outage include the replacement
of the inboard ASCO valves with new ASCO valves assembled without grease
and the replacement of the outboard ASCO valves with Valcor solenoid
valves.

If you require further information regarding this notification, please
direct them to William C. Kirchhoff, LaSalle Site Support Engineering,
extension 2927.

CECo Company Officer Informed at             am/pm on
The NRC was notified at                 on             and verified by


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Page Last Reviewed/Updated Thursday, March 29, 2012