United States Nuclear Regulatory Commission - Protecting People and the Environment

ACCESSION #: 9703270188




                                (315) 349-2660 FAX (315) 349-2605

MARTIN J.  McCORMICK JR. P.E.           March 20, 1997

Vice President                          NMP2L 1696

Nuclear Engineering

U.  S.  Nuclear Regulatory Commission

Attn: Document Control Desk

Washington, DC 20555

RE: Nine Mile Point Unit 2

Docket No.  50-410


Subject:  Part 21 - Borg-Warner Pressure Switches


Pursuant to 10CFR Part 21, Reporting of Defects and Noncompliance,

Niagara Mohawk Power Corporation (NMPC is submitting the attached report.

NMPC had previously notified the Commission of this issue on February 20,

1997, via telephone and facsimile.  The attached report contains the

information required by 10CFR21.21(c)(4).

                                        Very truly yours,

                                        Martin J.  McCormick Jr.

                                   Vice President Nuclear Engineering



xc:  Mr.  H.  J.  Miller, NRC Regional Administrator

     Mr.  S.  S.  Bajwa, Acting Director, Project Directorate I-1, NRR

     Mr.  B.  S.  Norris, Senior Resident Inspector

     Mr.  D.  S.  Hood, Senior Project Manager, NRR

     Records Management


1.   Name and address of the individual or individuals informing the


     Mr.  Martin J.  McCormick Jr.

     Niagara Mohawk Power Corporation

     Nine Mile Point Nuclear Station

     P.  O.  Box 63, Lake Road

     Lycoming, NY 13093

2.   Identification of the facility, the activity or the basic component

     supplied for such facility or such activity within the United States

     which fails to comply or contains a defect.

     The affected components are the following Borg Warner Pressure

     Switches (BWIP) supplied to Niagara Mohawk Power Corporation (NMPC

     and installed in Nine Mile Point Unit 2 (NMP2):

     o    Operator Model Number 85430 (BWIP Part Number 88743), NMPC

          purchase order number NMP2 - P304Y

     o    Operator Model Numbers 85960, 86060, and 86040 (BWIP Part

          Number 88739), NMPC purchase order numbers NMP2-P304Y and NMP2-


     o    Operator Model Numbers 85960, 86060, 86080, and 86040 (BWIP

          Part Number 86819), NMPC purchase order numbers NMP2-P304Y and


3.   Identification of the firm constructing the facility or supplying

     the basic component which fails to comply or contains a defect.

     Enertech of Brea, California, supplied the subject switches to NMP2.

4.   Nature of the defect or failure to comply and the safety hazard

     which is created or could be created b such defect or failure to


     Several BWIP pressure switches have failed during operation and

     initial calibration.  An evaluation has concluded that the switches

     are unable to consistently hold the correct reset point.  According

     to the manufacturer, the subject switches do not have an accurately

     adjustable reset value.  The relationship between the setpoint of

     the switches and their reset point is not linear nor consistent

     between different switches of the same model.  They are designed to

     operate with a maximum setpoint and minimum reset window only.  Due

     to the non-linear reset, setpoint drift over time may place the

     switches outside their acceptable tolerances.  As a result, an

     excessively high number of the switches are not consistently able to

     be initially calibrated to the desired setpoint, and once installed

     and calibrated, several failures have been experienced as the result

     of setpoint drift.


     The subject switches were supplied and recommended by the vendor as

     replacements for the original switches of the same model.  The

     vendor is aware of the specific setpoints associated with each

     switch part number ordered by Niagara Mohawk.  However, instead of

     providing switches designed to operate at the specific setpoint and

     reset, the vendor supplied replacement switches made to operate

     somewhere within the maximum setpoint and reset range for all

     switches of this type.  Initial calibration of newly installed

     switches is then required to set each switch to its required

     operating range.  It is during this initial calibration that a

     majority of the problem switches are rejected due to difficulties

     experienced in achieving the acceptable operating ranges for the


     Each of the operators identified under section (2) has BWIP switches

     within its hydraulic controls.  The effect of a switch failure on a

     given operator is a function of the switch application within the

     operator hydraulic control circuit; i.e., a valve failing open and

     unable to close, a valve failing closed and unable to open, or a

     valve failure in place.

     For the Control Building Chilled Water System (HVK) or Service Water

     System (SWP), due to their design and application, switch failure

     would cause the associated valve to fail in an intermediate open

     position and unable to modulate.  SWP valves 2SWP*TV35A and 35B

     provide temperature control for the control and relay room chillers.

     HVK valves 2HVK*T21A, 21B, 22A, and 22B provide individual

     temperature control for air conditioning units in both the control

     room and relay rooms.  If these valves were to fail, control/relay

     room temperature potentially could increase beyond its acceptable

     design range over a period of time if corrective action were not

     taken.  While control or relay room overheating (due to BWIP switch

     failure) is considered to be a less credible event than a Standby

     Gas Treatment System (GTS) system failure, these NMP2 components are

     being reported since this type of system reaction is possible.  It

     is to be noted that redundant air conditioning units are available

     in addition to the ability to manually control cooling flow if

     required.  However, under design basis assumptions neither are

     credited as being available.

     For GTS (2GTS*MOV2A, 2B, 3A, 3B, 28A, 28B, and 2GTS*PV5A, 5B), a

     pressure switch failure would prevent correct actuator response.

     Since the subject valves are located on the entrance, exit, cross-

     tie, and recirculation lines around each Standby Gas Filter Train,

     the system may not be able to perform its intended safety functions.

     Notwithstanding the fact that all systems are redundant and the

     ability exists to manually control flow around SWP valves 2SWP*TV35A

     and 35B, a deviation exists with the pressure switches for HVK, SWP,

     and GTS systems in that, assuming the coincident common-mode failure

     of switches or a second unrelated single failure (as required by the

     design basis and Part 21 guidelines), the switches potentially

     create a substantial safety hazard as defined by Part 21.  In

     addition, the excessively high failure rate during the initial

     calibration does constitute a substantial safety hazard as defined

     by Part 21.


     Presently an engineering operability determination is in place that

     documents reasonable assurance that the switches will operate as

     required.  This determination is based on having passed initial

     calibration testing (where most of the problem switches have been

     identified and rejected), positive test data trends of installed

     switch calibrations, and implementation of additional administrative

     controls which have established the calibration frequency of the

     BWIP switches at 18 months.  Previous to these actions, switches

     were adjusted when necessary during actuator preventive maintenance

     or when problems were experienced with the actuator.  NMP2 has

     experienced a significantly decreasing trend in failures of

     installed switches since initiating the 18-month calibrations of the


     This evaluation concludes that although operable at this time, under

     the guidance of Part 21, the BWIP pressure switches are reportable.

5.   The date on which the information of such defect or failure to

     comply was obtained.

     Niagara Mohawk identified the defect on February 18, 1997, as a

     potential Part 21 reportable condition.  The investigation was

     conducted in accordance with Nuclear Licensing Procedure NLAP-IRG-


6.   In the case of a basic component which contains a defect or fails to

     comply, the number and location of all such components in use at,

     supplied for, or being supplied for one or more facilities or

     activities subject to the regulations in this part.

     The following table lists the affected NMP2 components and the

     corresponding BWIP part numbers.

                 TABLE: Affected Switches and Components

                           NMPC Part 21 Report

NMP2 Component ID#                 Procurement Information

2GTS*MOV2A-ACT      Pressure, operator model #85430, originally supplied

                    on NMPC purchase order nos.  NMP2-P304Y, BWIP P/N

2GTS*MOV2B-ACT      88743.  Spare/replacement parts originally supplied

2GTS*MOV3A-ACT      under NMPC purchase order number NMP2-P304Y shall

2GTS*MOV3B-ACT      be qualified to BORG Warner Test Report No.  2125,

                    Rev.  B

2GTS*MOV28A-ACT     Pressure, operator model #85960, 86060, and 86040,

                    originally supplied on NMPC purchase order nos.

2GTS*MOV28B-ACT     NMP2-P304Y and NMP2-C015M BWIP P/N 88739.  Spare/

2GTS*PV5A-ACT       replacement parts originally supplied under NMPC

2GTS*PV5B-ACT       purchase order numbers NMP2*P304Y and NMP2-C051M

2GTS*MOV2A-ACT      shall be qualified to BORG Warner Test Report Nos.

2GTS*MOV2B-ACT      2125, Rev. B and 2140 Rev. A.










TABLE: Affected Switches and Components

NMPC Part 21 Report

NMP2 Component ID#                      Procurement Information

2GTS*MOV28A-ACT     Pressure, operator model #85960, 86080, 86060, and

                    86040, originally supplied on NMPC purchase order

2GTS*MOV28B-ACT     nos. NMP2-P304Y and NMP2-C051M, BWIP P/N

                    86819.  Spare/replacement parts originally supplied

2SWP*TV35A          under NMPC purchase order numbers NMP2-P304Y and

2SWP*TV35B          NMP2-C051M shall be qualified to BORG Warner Test

                    qualified to BORG Warner Test Report Nos. 2125,

2HVK*TV21A-ACT      Rev.  B and 2140 Rev.  A.




Number of BWIP Switches by NMP2 System No.:

GTS  - 22 switches

SWP  - 6 switches

HVK  - 12 switches

7.   The corrective action which has been, is being, or will be taken;

     the name of the individual or organization responsible for the

     action; and the length of time that has been or will be taken to

     complete this action.

     An operability determination was performed which verified that the

     affected components and systems in the plant were operable.  The

     determination is based on rejection of most of the bad switches

     during initial calibration, the absence of actuator failures since

     October 1996, and the significantly decreasing trend in switch

     failures following the establishment of 18-month calibrations of the


     NMP2 will either replace the subject switches with switches designed

     to operate at the specific setpoints required or replace the

     affected actuators with a different model.  The projected date for

     completion of the corrective actions is May 1, 1998.  Until

     corrective actions are completed, periodic surveillances will

     continue to verify operability of the affected NMP2 components.

8.   Any advice related to the defect or failure to comply about the

     facility, activity, or basic component that has been, is being, or

     will be given to purchasers or licensees.

     Surveillance frequencies of the affected actuators and/or switches

     should be increased as necessary to control setpoint drift.



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