ML20237A653
| ML20237A653 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 12/03/1987 |
| From: | Boardman J, Gagliardo J, Seidle W, Tapia J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | |
| Shared Package | |
| ML20237A627 | List: |
| References | |
| 50-285-87-30, EA-87-210, NUDOCS 8712150148 | |
| Download: ML20237A653 (8) | |
See also: IR 05000285/1987030
Text
EA 87-210
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APPENDIX
l!.S. NUCLEAR REGULATORY COMMISSION
REGION IV
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NRC Inspection Report:
50-285/87-30
Operating License: DPR-40
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Docket:
50-285
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Licensee: Omaha Public Power District (0 PPD)
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1623 Harney Street
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Omaha, Nebraska 68102
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Facility Name:
Fort Calhoun Station, Unit 1 (FCS)
Inspection At:
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Inspection Conducted:
November 2-6, 1987
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Inspectors:
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N/JE[i/
W.C.SeidlegChief,OperationalPrograms
Date
Section, Division of Reactor Safety
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(MW
n /So[T'7
J. J.' Boardman, Reactor Inspector, Operational
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Rtograms Section, Division of Reactor Safety
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D
, Pr'ojectflingineer, Project
_wi
n Is /n
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apict
Datd
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ion A, DivisioY of Reactor Projects
Accompanied
By:
A. B. Beach, Deputy Director, Division of
Reac or Projects
exit interview on
fNovep}ber6,1987
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Approved:
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Date f
)3, 3 /)
J(E.G(gliardo, Chief,OperationsBranch
Division of Reactor Safety
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8712150148 871210
ADDCK 05000285
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Inspection Summary
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Inspection Conducted November 2-6, 1987 (Report 50-285/87-30)
Area Inspected:
Special, unannounced inspection of licensee corrective actions
in response to water intrusion into the Instrument Air System.
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Results: Within the area inspected, one violation was identified (failure to
establish procedures as required by Technical Specification 5.8.1, paragraph 2.c
of this report).
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DETAILS
1.
Persons Contacted
Licensee
- R. Andrews, Division Manager, Nuclear Production
- W. Gates, Plant Manager
- S. Gambhir, Section Manager, Generating Station Engineering
- M. Core, Supervisor, Maintenance
- J. Fisicaro, Supervisor, Nuclear Regulatory and Industry Affairs
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- T. Patterson, Manager, Technical Support
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- J.-Gasper, Manager, Administrative and Training Services
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- R. Jaworski, Section Manager, Technical Services
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K. Miller, Supervisor, Mechanical Maintenance
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- L. Kusek, Supervisor,.0perations
- D. Matthews, Supervisor, Licensing
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- L. Gundrum, Plant Licensing Engineer
- T. McIvor, Supervisor, Technical
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R. Mueller, Plant Engineer
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- A. Richard, Manager, Quality Assurance
- M. Eldem, Manager, Mechanical Engineering, Genere',ing
Station Engineering
"G. Roach, Supervisnr
- S. Willret, Supervisor, Administrative Services and Security
M. Ellis, I&C Supervisor
- R. Scofield, Supervisor, Outage Projects
C. Ovici, Senior Engineer
NRC
- B. Beach, Deputy Director, Division of Reactor Projects, Region IV
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- P. Harrell, Senior Resident Inspector
- T. Reis, Resident Inspector
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- Denotes attenCance at the exit interview on November 6, 1987.
The NRC inspectors also interviewed additional licensee personnel during
the inspection period.
2.
Licensee Corrective Action Program for Systems Important te Saf^'*
The NRC inspectors accomplished a performance oriented revit- nt the
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licensee's corrective action responses to the events involvit.;
- er in
the Instrument Air (IA) System occurring on July 6, August 25, and
September 23, 1987, with the following findings (see NRC Inspection
Report 50-285/87-27 for a detailed discussion of these events):
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a.
July 6,1987, Event - Introduction of Fire System Water into the
Instrument Air Syste.n as a Result of Inadequate Licensee Procedures
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for the Testing of a Fire System Deluge Valve
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The NRC inspectors found that for the period of July 6-8, 1987,
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licensee actions to blowdown water from the IA System and to
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determine the extent and amount of water intrusion were neither
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accomplished in accordance with approved procedures nor documented
to permit subsequent analysis.
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Interviews and discussions with licensee personnel did not reveal any
involvement of Shift Technic,al Advisors (STAS) with the actions and
decisions following this event, or the events of August 25 and
September 23, 1987.
No approved procedures were identified which were in effect either at
the time of the event or subsequently that addressed analysis and
corrective actions of abnormal conditionc for systems which are
important to safety.
There was no documentation of Plant Review Committee (PRC)
involvement until August 6, 1987.
Discussions with licensee
personnel indicated that at the time of, and subsequent to, the event
the absence of the Plant Manager and the Operations Supervisor
precluded having the quorum required for a PRC meeting.
The acting
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plant manager, when interviewed by the NRC inspectors, did not
indicate that he considered the event significant and could not
recall whether he contacted offsite-licensee management, or requested
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offsite technical assistance at the time of the event.
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As discussed in NRC Inspection Roport 50-285/87-27, licensee
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personnel did not take corrective action to determine that the
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IA system met its design base dew point of -20 F until late October
1987.
In addition, as determined by subsequent tests, the initial
readings were incorrect.
The first two instruments used to determine
dew point were neither in the licensee's metrology program, nor had
calibration stickers. One instrument was used without having
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approved site procedures; the other instrument was apparently not
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designed for measurement of extremely low dew points.
The above findings reveal weaknesses in the implementation of
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corrective action.
b.
Review of Licensee's Actions After the July 6, 1987, Event to
Determine Operability of Safety-Related Components, the Adequacy of
the Justification for Continued Operation (JCO), and Component
Design Adequacy
The NRC inspectors reviewed equipment operability after the July 6,
1987, event and licensee actions to verify the operability of the
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plant.
This review was specifically concerned with the effect of
water on components required to maintain the plant in a safe
condition.
The first step taken in this effort was to review Abnormal Operating
Procedure (A0P) No. 17 " Loss of Instrument Air System." As noted in
item G of Appendix A to Enforcement Action (EA)87-210, which is part
of NRC Inspection Report 50-285/87-27, this procedure was found to
be inadequate in that it did not address the affect.of loss of ~-
instrument air on all safety-related equipment.
The results of the
review during this inspection disclosed that the procedure.did not
list all safety-related valves equipped with safety-related air
accumulators (21) and conversely, it contained valves which have air
accumulators not considered to be safety-related (44).
The purpose
of this procedure is to describe the actions to be taken following a
complete loss of the IA System.
As such, this procedure should have
been utilized when responding to the intrusion of water into the
1A System by identifying-those valves required to maintain the plant
in a safe condition, which may have been adversely affected.
After
this identification, the operability of the valves could have been
immediately addressed. As noted in Item B of Appendix A to EA 87-210,
the licensee did not' commence a formal documented program for determining
operability until 3 days after the July 6 event.
In order to assess the impact of water intrusion into the IA System,
it became necessary to generate a list identifying which components
may have been affected.
From this list it was learned that there are
78 valves with air accumulators -in the plant and that 34 of these are
safety-related. Of the 34 valves, 21 require air accumulators to
fail-safe and mitigate the consequences of a design basis accident,
while 13 valves require the air accumulator to provide repositioning
of the valve after the accident.
The results of the three formal blowdown programs were then reviewed
with particular attention given to determination of the extent of
migration of the water.
For each of the 34 safety-related valves, it
was determined if water was found and if the valve-was tested for
operability by cycling after each phase of blowdown. No failures of
the valves in question were identified during the cycling program.
For those air-operated valves that were not tested, the licensee
issued a JC0 providing assurance that the plant will. continue to
operate safely until-those-remaining valves can be cycled. This
document was reviewed by the NRC inspectors and found to provide a
sufficient and correct explanation for allowing continued operation.
In September 1985 the NRC performed a Safety Systems Outage and
Maintenance Inspection (SSOMI) at Fort Calhoun Station.
In response
to a SS0MI finding, OPPD committed to a test program for valves with
air accumulators installed to verify that the air accumulators
functionally met their design basis criteria. OPPD's first steps in
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satisfying their commitment was to determine how many times the
valves would be expected to be repositioned and how long the accumulator
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would have to maintain the valve position.
It was determined that
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22 valves would be required to function for 1,000 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> using their
air accumulators after a large break LOCA.
In that it is unlikely
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that an accumulator can maintain pressure for such a long period,
OPPD has taken the position that modification to the valve operators
or a redefinition of their design functions should be considered.
Pending such action, the licensee issued a JC0 supporting operation
through the next cycle.
The NRC inspectors looked into the determination of the boundary of
the IA System with respect to the statement that the loss of
instrument air alone does not result in any safety function being
compromised.
The NRC inspection focused nn the adequacy of the accumulators,
solenoids, and check valves to perform their intended function. This
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review identified a check valve test program conducted to assure the
operability of check valves.
It was determined that of the 34 valves
of concern, only 12 have had a check valve operability test.
Three
of the 12 check valves tested failed to maintain air pressure. One
of the 3 valves failed twice. This information was not considered in
the generation of the JC0 and is considered an open item (285/8730-01)
pending the revision of the JC0 to incorporate what effect, if any,
the noted failure rate will have on the justification to continue
operation.
On October 29, 1987, during the enforcement conference held in the
NRC Region IV offices, OPPD maintained that by the end of the day on
July 6, full operability had been restored (see pages 1-10 of OPPD
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Letter LIC-87-744 to NRC Region IV Administrator). This conclusion
appears to be in error based on the following factors:
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(1) the initial actions only included a generic blowdown of
regulators,
(2) the actions taken by the licensee did not define specific valves
which were important to safety, and
(3) no valves were cycled to verify operability until July 9, 1987.
Operability was ultimately assured as a result of the systematic
thr ee-phase blowdown program.
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c.
August 25, 1987, Event - Introduction of Demineralized Water (DW)_
Into the IA System Via an Unapproved Modification Between the DW
and IA Systems in the Water Treatment Room
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Until questioned by the NRC inspectors, licensee personnel had
developed no documented, technically verified scenario adequately
explaining the introduction of DW into the IA System in the water
treatment room.
Discussions with different licensee personnel
resulted in apparently conflicting information.
Cause of water intrusion into .the IA System included:
The earlier (estimated as 1980) installation of an unapproved
modification that allowed interconnection of the DW and
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IA Systems.
This modification consisted of a solenoid valve, >.
timer, a manually operated IA valve, and clear plastic tubing
which was used to connect the modification.
The connection to
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the DW system was to a port in the wall of the body of CV-86, a
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diaphram valve which was used as a check valve for this
application. Once each day during the DW demineralized
back-wash cycle, the solenoid valve in the modification was
opened for approximately 22 minutes by the timer.
During this
22-minute period the DW system pressurized the modification up
to the added IA manual valve, which was closed, but not tagged.
The purpose of this unauthorized modification was not known, and
the person involved with it is deceased. This modification did
not appear on DW or.IA Piping and Instrumentation Drawings (P& ids)
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according to licensee personnel.
The system pressure of tne DW
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system was approximately 109 psig; that of the IA System was
approximately 101 psig. As a result, the actual interconnection
of the DW and IA Systems would result in intrusion of DW at a
rate of about 0.09 gpm. When drain valves in the IA System were
open with the DW/IA systems interconnected, the intrusion rate
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could increase to approximately 0.7 gpm.
After accomplishment on August 24, 1987, of corrective
maintenance (replacement of a section of clear plastic tubing
which was leaking) on the unauthorized modification, a
maintenance mechanic opened the previously closed (but untagged)
manually operated IA valve which had isolated the DW system from
the IA System during previous back-flush cycles.
Since the DW
system was not in the demineralized back-flush cycle, water did
not flow from the DW system into the IA System at that time.
During the next demineralized back-flush cycle, shortly after
midnight on August 25, 1987, the solenoid valve in the
modification opened causing DW intrusion into the IA System.
The NRC inspectors found that the licensee had no documented
procedure or policy which prohibited the repositioning of any
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safety-related, valve, damper, switch, circuit breaker, or other
control device by maintenance personnel without specific approval.
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Fort Calhoun Station TS 5.8.1 requires that procedures be
established, implemented, and maintained that meet or exceed the
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minimum requirements of ANSI N18.7-1972, Sections 5.1 and 5.3, and
Appendix A of Regulatory Guide 1.33.
ANSI N18.7-1972, Section 5.1.6.1, requires that maintenance which can
affect the performance of safety-related equipment shall be in
accordance with written procedures; Section 5.3.5(3), under
post-maintenance return to service, requires that instructions shall
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be included (or referenced) for returning equipment to normal
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operating status, giving special attention to systems the.t can be
defeated by leaving valves, breakers, or. switches mispositioned.
The licensee's failure to have a written procedure or instruction' to
preclude the mispositioning of valves, breakers, or switches' constitutes-
an apparent violation of the above requirement (285/8730-02).
d.
September 23, 1987, Event - Failure of Emergency Diesel
Generator (EDG) No. 2 Cooling System Exhaust Damper to Open Resulting
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in the Shut-Down of EDG No. 2 Due to High Temperature
Licensee personnel stated that the failure of the damper to open was
caused by the restriction of a pilot valve orifice. The restriction
was a tightly adhering annular build-up of foreign matter. This
matter could not be dissolved using acetone, water, nitric acid, or
hydrochloric acid.
It was ultimately removed by licensee' personnel
by reaming the orifice. The foreign matter was then disposed of
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without analysis.
This action precluded determining the source
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of the foreign matter. Data presented to the NRC on October 29, 1987,
indicates that there were previous instances of " plugged orifices."
This is another example of the ineffectiveness of the licersee's
corrective action program to correct and prevent recurrence of
conditions which are adverse to quality.
3.
Exit Interview
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The NRC inspectors met with the licensee representatives denoted in.
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paragraph 1 and the NRC resident inspectors at the conclusion of the
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inspection on November 6, 1987. The NRC inspectors summarized the,
purpose, scope, and findings of the inspection.
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