ML20236F416
| ML20236F416 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 10/19/1987 |
| From: | Harrell P, Reis T, Westerman T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | |
| Shared Package | |
| ML20236F382 | List: |
| References | |
| 50-285-87-27, NUDOCS 8711020132 | |
| Download: ML20236F416 (5) | |
See also: IR 05000285/1987027
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APPENDIX A
U.S. NUCLEAR REGULATORY COMMISSION
REGION IV
NRC Inspection Report:
50-285/87-27
License:
Docket:
50-285
Licensee:
Omaha Public Power District (0 PPD)
1623 Harney Street
Omaha, Nebraska
68102
Facility Name:
Fort.Calhoun Station (FCS)
Inspection At:
Inspection Conducted:
September 23 through October 2, 1987
Inspectors:
7 h.
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P. H. Harrell, Senior Resident Reactor
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Inspector
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7. Reis, Resident Reactor Inspector
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Approved:
T. F. Westerman, Chief, Projects Section 8
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Inspection Summary
Inspection Conducted September 23 through October 2, 1987 (Report 50-285/87-27)
Areas Inspected:
Routine, unannounced inspection of the instrument air system.
Results:
One potential violation was identified (inoperability of emergency
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diesel generators, paragraph 2).
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DETAILS
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1.
Persons Contacted
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- R. Andrews, Division Manager, Nuclear Production
- W. Gates, Plant Manager
- C.~Brunnert, Supervisor, Operations Quality Assurance
- M. Core, Supervisor, Maintenance
- T. Dexter, Supervisor, Security
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- J. Fisicaro, Supervisor, Nuclear Regulatory and Industry Affairs
J. Foley, Supervisor, I&C and Electrical Field Maintenance
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H. Faulhaber, Manager, Electrical Engineering,. Generation Station
Engineering
- J. Gasper, Manager, Administrative and Training Services
- L. Gundrum, Plant Licensing Engineer
- R. 'Jaworski, Section Manager, Technical Services
J. Kecy, Acting Reactor Engineer
R. Kellogg, Technical Services Engineer
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M. Klanderud, Licensing Engineer
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.L. Kusek, Supervisor, Operations
D. Munderloh, Plant Licensing Engineer
- T. McIvor,' Supervisor, Technical
R. Mueller, Plant Engineer
- A. Richard, Manager, Quality Assurance
G. Roach, Supervisor, Chemical and Radiation Protection
- R. Scofield, Supervisor, Outage Projects
- D. Trausch, Nuclear Production Engineer
S. Willrett, Supervisor, Administrative Services Security
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- Denotes attendance at the monthly exit interview.
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The NRC inspector also contacted other plant personnel including operators,
technicians, and administrative personnel.
2.
Instrument Air System
On September 23, 1987, the licensee performed a regularly scheduled
surveillance test on Emergency Diesel Generator (EDG) 2 to prove
operability in accordance with Technical Specification (TS) 2.7
requirements.
EDG 2 was loaded as specified in the test procedure and
approximately 9 minutes later the EDG tripped off due to high temperatures
in the engine cooling water system.
The licensee tagged out EDG 2 and performed trouble shooting activities to
determine the cause of the trip.
As a result of the troubleshooting, the
licensee determined that the most likely cause of the event was the
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failure of the exhaust damper on the diesel radiator to open.
Without the
damper open, no radiator. cooling air flow was available and the engine
cooling water temperatures increased.
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The licensee disassembled the air motor used for opening and closing the
radiator exhaust damper and found an accumulation.of water in the motor
air accumulator. They found that the pilot valve used to direct air into
the motor was coated with a gummy substance.
The radiator exhaust damper
air motor' uses the plant instrument air system as a prime mover.
The
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licensee, cleaned up and reassembled.the. air motor on EDG 2.
Subsequent
testing on the EDG 2 damper indicated the damper operated satisfactorily.
Discussions continued between.the NRC resident inspector and the licensee,
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and on the' afternoon of September 23, 1987, the licensee decided to block
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the radiator exhaust damper for both EDGs open to ensure that the EDGs
would be available for operation should emergency onsite power be required
during an event.. Since the radiator exhaust damper on EDG 2 had failed to
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operate on demand, no assurance could be provided that the damper on EDG 1
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would operate,-if required.
The licensee subsequently disassembled the air motor on EDG 1 and found
similar circumstances as was noted with EDG 2 air motor.
Water was found
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in the air accumulator and the internals of the air moter were also coated
with a gummy substance.
The plant instrument air system provides a supM y of air to the dampers on
each diesel via a common header.
During July 1987, while performing a
surveillance test on the fire sydtem, water entered the instrument air
system through an interface between the air and fire water system.
The
air was used as part of a " dry pipe" system in the fire main. When the
licensee realized that water had entered the instrument air system, a
systematic blowdown of the system air lines and accumulators was performed
to remove the water from the system.
The air system blowdown was
established by review of the applicable piping drawings to determine the
accumulators and air piping risers to be checked for the presence of
water.
However, the piping drawings did not show the installation of the
accumulators for the EDG air motors.
For this reason, the air
accumulators were not checked for the presence of water.
This oversight
resulted in the apparent failure of the damper on EDG 2 to operate on
demand. Water in the air system provided a potential common mode failure
due to the detrimental affects of the water on components designed to
operate using dry air.
TS 2.7 states, in part, that the reactor shall not be heated up or
maintained at temperatures above 300 F unless both diesel generators are
The Definitions section of the TS states, in part, that a component shall
be operable when it is capable of performing its specified function.
Implicit in this definition, shall be the assumption that all necessary
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auxiliary equipment that are required for the component to perform its
function are also capable of performing their related support function.
Therefore, EDG 2 was considered to be inoperable in that auxiliary equipment,
the radiator exhaust damper, failed to perform its support function.
Also, no assurance,could be provided that the radiator exhaust damper for
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EDG 1 would perform its support function due to both dampers being
susceptible to the common mode failure of water.in the instrument air
system.
This is considered to be an apparent violation of NRC
requirements (285/8727-01).
In. addition, potential weaknesses involving
the adequacy of the plant instrument air system design and the adequacy-
of the' licensee's corrective actions, once the problem was know to exist
in July 1987, need to be addrassed.
Subsequent to the failure of the EDG2 to operate on demand and discussions
with the NRC, the licensee continued to perform corrective actions _to
ensure that all the water was removed from the air system and to verify
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that all safety related components functioned normally,
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3.
Exit Interview
The NRC inspectors met with Mr. R. L. Andrews (Division Manager - Nuclear
Production) and other members of the licensee staff at the_end of this
inspection.
At this meeting, the NRC inspectors summarized the scope of
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the inspection and the findings.
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APPENDIX B
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PROPOSED ENFORCEMENT CONFERENCE AGENDA
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' OMAHA PUBLIC' POWER DISTE,CT
OCTOBER 29,19d7
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'L. J. Callan
I.
Introduction and Purpose of Meeting
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Introduction of water into the instrument air
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system
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II.
Licensee Presentation
OPPD Staff--
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III.'NRC Comments-
L. J. Callan
-IV.
D.'A. Powers
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V.
Licensee Response
(.0 PPD Staff
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VI.
Closing Comments
L. J. Callan
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