Protecting People and the EnvironmentUNITED STATES NUCLEAR REGULATORY COMMISSION
ACCESSION #: 9703270188
NIAGARA MOHAWK
G E N E R A T I O N NINE MILE POINT NUCLEAR STATION/LAKE ROAD, P.O.
BUSINESS GROUP BOX 63, LYCOMING, NEW YORK 13093/TELEPHONE
(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
NPF-69
Subject: Part 21 - Borg-Warner Pressure Switches
Gentlemen:
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
MJM/KLL/kap
Enclosure
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
ATTACHMENT
1. Name and address of the individual or individuals informing the
Commission.
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-
C051M
o Operator Model Numbers 85960, 86060, 86080, and 86040 (BWIP
Part Number 86819), NMPC purchase order numbers NMP2-P304Y and
NMP2-C051M
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
comply.
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.
1
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
switches.
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.
2
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
switches.
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-
140.
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.
2GTS*MOV3A-ACT
2GTS*MOV3B-ACT
2SWP*TV35A-ACT
2SWP*TV35B-ACT
2HVK*TV21A-ACT
2HVK*TV21B-ACT
2HVK*TV22A-ACT
2HVK*TV22B-ACT
3
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.
2HVK*TV21B-ACT
2HVK*TV22A-ACT
2HVK*TV22B-ACT
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
switches.
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.
4
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