ML20207T626
| ML20207T626 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 03/04/1987 |
| From: | William Orders, Peebles T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML20207T607 | List: |
| References | |
| 50-369-87-05, 50-369-87-5, 50-370-87-05, 50-370-87-5, NUDOCS 8703240190 | |
| Download: ML20207T626 (9) | |
See also: IR 05000369/1987005
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UNITED STATES '
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NUCLEAR REGULATORY COMMISSION
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REGION 11
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101 MARIETTA STREET, N.W.
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ATLANTA, GEORGI A 30323
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Report Nos.: 50-369/87-05 and 50-370/87-05
Licensee: Duke Power Company
422 South Church Street
Charlotte, NC 28242
Docket Nos.:
50-369 and 50-370
License Nos.: NPF-9 and NPF-17
Facility Name: McGuire 1 and 2
Inspection Conducted: January 21, 1987 - February 20, 1987
Inspec or:
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W. Orders, fenior Resident Inspector-
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Dat'e' Signed
Accompanying Personnel:
S. Guenther
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Approved by:
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M T. A. Peebles, Section Chief
Date Signed
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Division of Reactor Projects
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SUMMARY!,
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Scope: This routine unannounced inspection' involved ~the areas,of operationi
safety verification, surveillance testing, maintenance activ_ities, and follow-up
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of previous enforcement actions / inspection findings.
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Results: Of the areas inspected, one violation was identified. in the area of
surveillance procedure adequacy.
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REPORT DETAILS
1.
Licensee Employees Contacted
- T. McConnell, Plant Manager
- B. Travis, Superintendent of Operations
- D. Rains, Superintendent of Mairtenance
B. Hamilton, Superintendent of Technical Services
- N. McCraw, Compliance Engineer
- M. Sample, Superintendent of Integrated Scheduling
N. Atherton, Compliance
- R. White, Instrument and Electrical Maintenance
- S. Copp, Maintenance Planning
- B. Gragg, Performance / Production Specialist
Other licensee employees contacted included construction craftsmen,
engineers, technicians, operators, mechanics, security force members, and
office personnel.
2.
Exit Interview
The inspection scope and findings were summarized on February 23, 1987
with those persons indicated in paragraph 1 above. One violation concerning
the adequacy of a Slave Relay Test procedure, and two unresolved items
(UNR), concerning the determination of system / component operability and
the control of temporary modifications were discussed. The inspectors
reviewed proprietary information during the course of their inspection,
however, no proprietary information is contained within this report.
3.
Unresolved Items
An unresolved item (UNR) is a matter about which more information is
required to determine whether it is acceptable or may involve a violation
or deviation. Two new UNRs are discussed in this report.
4.
Plant Operations (71707, 71710)
The inspection staff reviewed plant operations during the report period,
to verify conformance with applicable regulatory requirements. Control
room logs, shift supervisors' logs, shift turnover records and equipment
removal and restoration records were routinely reviewed. Interviews were
conducted with plant operations, maintenance, chemistry, health physics,
and performance personnel.
Activities within the control room were monitored during shifts and at
shift changes. Actions and/or activities observed were conduc7ed as
prescribed in applicable station administrative directives. The esmplement
of licensed personnel on each shift met or exceeded the minimum required
by Technical Specifications.
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Plant tours taken during the reporting period included, but were not
limited to, the turbine buildings, auxiliary building, units 1 and 2
electrical equipment rooms, units 1 and 2 cable spreading rooms, and the
station yard zone inside the protected area.
During the plant tours, ongoing activities, housekeeping, security,
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equipment status and radiation control practices were observed.
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Unit 1 Operations
The unit began the reporting period at full power and maintained that
operating status until the afternoon of January 30, 1987, when both
trains of containment air return and hydrogen skimmer fans (VX) were
determined to be inoperable due to a design deviation, thereby invoking
the requirements of Technical Specification (TS) 3.0.3.
A unit shutdown
was commenced but was terminated shortly thereafter when the licensee
obtained an eight-hour extension of the shutdown action statement. The
licensee believed (and the NRC concurred) that the design deviation,
which raised doubts about the operability of the VX system, could be
promptly corrected and that the safety hazard associated with continued
operation for that period of time was less than that associated with
a plant shutdown and restart transient.
The licensee was, however,
unsuccessful in completing the repairs within the eight-hour extension
period and resumed a unit shutdown later that evening. Work on the VX
system was completed early on January 31, and the load reduction was
secured at about 83 percent power. The details surrounding the VX system
design deviatin and the associated enforcement implications are discussed
in NRC Special Inspection Report Nos. 50-369,370/87-04.
Unit I was returned to full power and remained there until February 12,
1987, when repeated low level alarms in the IB reactor coolant pump's
upper oil reservoir necessitated a reduction in power to about 10 percent
to allow a containment entry to determine whether the alarms were caused
by faulty instrumentation or an oil leak. An oil leak was confirmed and
the unit was placed in Mode 2 (hot standby) while repairs were made. The
licensee took advantage of the shutdown to make repairs to the main
feedwater (CF) pump turbine high pressure steam stop valves.
The same
valves on the Unit 2 CF pumps had failed to close properly during a trip
on January 20.
Unit I was placed back on line on February 14 and was operating at about
58 percent power at 3:57 p.m. on February 16 when a fire was detected
under the high pressure (hp) main turbine.
The licensee declared a
Notification of Unusual Event (NOVE) at 4:07 p.m. , as required by the
plant's Emergency Plan.
The fire, which was caused by oil-soaked
insulation covering the lower portion of the hp turbine, was brought under
control at about 4:07 p.m.,
but was not extinguished until 5:00 p.m.
because of the hostile and confined environment beneath the turbine. The
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unit remained on line throughout the incident, and the NOUE was
terminated. A search for the source of the oil, which caused the fire,
failed to locate an active leak and led the licensee to conclude that the
oil had been spilled during turbine maintenance in the last outage.
Shortly after resuming full power operation on February 17, the licensee
detected a significant increase in the sodium ion concentration in the
entire secondary system. This forced a reduction in load to 30 percent
until the source of the contamination could be isolated and the sodium
concentration reduced. A leak was discovered in a plant heating water
converter, which allowed corrosion inhibiting chemicals in the heating
water system to return to the condensate storage tank with the condensed
auxiliary steam.
Feed and bleed operations restored normal sodium ion
concentrations late on February 17, and full power was reached during the
morning of February 18.
Unit 1 tripped from 100*4 power at 8:26 p.m. on February 18, when the IC
reactor coolant pump's safety and power supply breakers tripped due to a
ground fault relay (50-G) actuation.
This resulted in a reactor trip,
since power was above the permissive (P-8) setpoint.
All systems
functioned normally during the trip and the unit was maintained in hot
shutdown (Mode 3) until the cause of the ground fault could be found. The
fault was traced to a failed surge capacitor in the motor's power supply,
which was readily replaced with a spare from another unit in the Duke
System. The. unit was restarted and placed back on line at 6:30 a.m. on
February 20.
Unit 2 Operations
Unit 2 began the reporting period in Mode 3, having sustained a reactor
trip on January 20, 1987, as discussed in NRC Inspection Report
Nos. 50-369, 370/87-02. The 2A CF pump suffered significant damage to its
shaft and seals and some casing damage as well. The unit was restarted on
January 24 and operated at about 58 percent power, the maximum capability
with a single operable main feedwater pump, while the 2A CF pump underwent
repair.
On January 30, Unit 2 entered TS 3.0.3, when both trains of VX were
declared inoperable.
The ensuing chain of events essentially parallels
those previously discussed under Unit 1 Operations, except that Unit 2
power was reduced to about 53 percent prior to restoring VX system
operability and exiting TS 3.0.3.
Repairs to the 2A CF pump were complete on February 4 and a load increase
was commenced but had to be terminated when the outboard bearing on the
pump exhibited a high operating temperature.
The pump was, once again,
removed from service and the bearing was replaced. The unit returned to
full power operation on February 6, and operated at essentially full power
for the remainder of the reporting period.
No violations or deviations were identified.
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5.
Surveillance Testing (61726)
Selected surveillance tests were analyzed and/or witnessed by the
inspector to ascertain procedural and_ performance adequacy and conformance
with applicable Technical Specifications.
Selected tests were witnessed to ascertain that current written approved
procedures were available and in use, that test equipment in use was
calibrated, that test prerequisites were met, that system restoration was
completed and test results were adequate.
a.
Containment Spray Heat Exchanger Performance Testing
While reviewing the Unit 2 Performance Test (PT) Log on February 11,
1987, the inspector noted that PT/2/A/4208/04B, " Train 2B Containment
Spray Heat Exchanger Performance Test", had been entered in the log
at 1:10 p.m., on February 9, but had not yet been completed. Part of
that PT involves heating up the refue.?g water storage tank (FWST)
with installed electric heaters to create a heat load so that a
containment spray (dS) heat exchanger heat balance can be performed.
The FWST heaters normally are interlocked to trip off at a temperature
below that necessary to perform an adequate capacity test / heat balance
on the NS heat exchanger. Step 8.5 of the PT directs that a lead be
lifted in the heater control circuitry so that the heaters remain
energized to elevate the FWST temperature to approximately 92 degree
Fahrenheit (F). This step requires independent verification to ensure
that adequate administrative controls are maintained over the lifted
lead.
The Unit 2 FWST heater control lead was lifted in accordance with
the PT during the evening of February 9 and the Operations Staff
was advised to monitor FWST temperature to ensure that the 100
degree Fahrenheit (F) Technical Specification limit was not exceeded.
Through an apparent misunderstanding, the Unit 1 Operations Staff
was _ led to believe that an NS heat exchanger capacity test was also
scheduled for Unit 1.
lhey noted, however, on the evening of
February 10, that the Unit 1 FWST heaters were cycling to maintain
normal temperature rather than remaining on continually to raise the
temperature in preparation for the anticipated heat balance test.
Believing that the Performance Group had erred by failing to lift the
FWST heater control lead, the Operations Staff had the Unit I lead
lifted.
Station Directive (SD) 4.4.2, " Control of Temporary Modifications",
defines a " lifted lead" as a conductor previously utilized as an
active system component that is temporarily disconnected and includes
it in a list of fourteen types of temporary modifications (e.g.,
mechanical jumpers, temporary blank flanges). Activities associated
with a test under the direction of an approved procedure (e.g. ,
PT/2/A/4208/04B) may be excluded from the requirements of the
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directive if the procedure includes appropriate steps for the
installation and removal of the temporary change,
including
provisions for independent verification.
The Unit 1 FWST heater control lead lifted on February 10 was not
removed in accordance with the administrative controls established
by SD 4.4.2, nor was the lead lifted under the guidance of the NS
heat exchancer PT.
During the exit interview the licensee's
representatives informed the inspectors that the Unit 1 FWST heater
lead had been lifted under the guidance of IP/0/A/3090/02,
" Controlling Procedure for Instrument and Electrical Troubleshooting",
which incorporates provisions for independent verification and
documentation of lifted leads. As of February 24, the licensee has
been unable to produce .the completed copy of that proceddre,
therefore, this matter will remain unresolved.
This UNR 369/87-05-01:
Resolve whether administrative controls were used to lift FWST heater
b.
Slave Relay Testing
Both units were on line on the morning of February 4,1987, and the
"B" train of the control room ventilation and chill water (VC/YC)
system was operating in its normal configuration, with train
"B" of
Unit 2 nuclear service water (RN) supplying the heat sink. The
"A"
train of VC/YC was out-of-service at the time and appropriately
logged.as inoperable in the Technical Specifications Action Item Log
(TSAIL).
The "B" VC chiller condenser can be aligned to receive RN flow from
either Unit's
"B"
train essential RN supply header.
However,
regardless of which unit is supplying the RN, the "B" VC condenser
discharge can only return to the Unit 1
"B" train essential RN return
header and must pass through valve 1RN-2978, the header isolation
valve.
1RN-2978, if not already open, will cycle to the open
position in response to a safety injection signal.
That safety
function is periodically tested during performance of the " Slave
Relay Test" procedure, PT/1/A/4200/28.
PT/1/A/4200/28 was in progress on February 4, 1987. Step 12.54.4 of
that PT directs the operator to ensure that IRN-2978 (among other
valves) is closed so that when its associated slave relay is
energized (Step 12.54.5) it can be verified to open (Step 12.54.6) as
designed. When 1RN-297B was closed it blocked the return path of RN
cooling water from the
"B"
VC chiller condenser and initiated a
protective trip of the chiller unit.
Step 12.54.1 of the PT directed the operator to " ensure RN Pump 18 is
off and all necessary loads are being fed from Train A".
This failed,
however, to address the fact that the "B" VC chiller can be aligned
to the "2B" essential RN header, as it was on February 4, and resulted
in an unnecessary trip of the "B" VC chiller, an engineered safety
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feature.
This placed both units in a precarious situation since the
"A" train of VC/YC was already out-of-service, and may have forced a
shutdown of both units pursuant to the requirements of TS 3.0.3 if
the "B" VC chiller had not restarted.
PT/1/A/4200/28 proved to be deficient, in that it failed to
adequately address the necessary VC/YC and RN system alignments to
preclude a protective trip of the "B" VC chiller when its heat sink
was removed.
Step 12.54.1 addressed the alignment of the Unit 1 RN
System, but failed to recognize and address the interface between the
Unit I and 2 RN trains as it relates to VC condenser cooling. This
procedural inadequacy is considered to be a violation of TS 6.8.1.
This is Violation 369,370/87-05-02:
TS 6.8.1 - Inadequate slave
relay test caused VC chiller trip on loss of RN flow.
A second NRC concern, relative to this incident, involves the
licensee's
interpretation
and evaluation
of component / system
operability.
In its response to a previous NRC violation
(369/85-03-03,370/85-03-02), the licensee sttted that future chiller
trips would result in the chiller being declared inoperable. During
this incident, however, the
"B"
VC chiller was not declared
inoperable when it tripped, and the units did not enter TS 3.0.3,
despite the fact that the cause of the chiller trip was not
immediately known and it was not a foregone conclusion that the
chiller could be readily restarted.
These concerns, regarding system operability, were discussed at
length with licensee management at the McGuire facility.
The
inspector was also given the opportunity to review a new Station
Directive which is being developed to provide additional operator
guidance on making operability determinations.
The inspector's
concerns regardir.g the Duke Power Company philosophy on the
operability of tripped rotating equipment have been relayed to
NRC Region II and the Office of Nuclear Reactor Regulation for
resolution.
This is UNR-369,370/87-05-03:
Resolve caoncerns re
operability of tripped rotating equipment.
One violation was identified, as described in paragraph 5.b. above,
and no deviations were identified.
6.
Maintenance Observations (62703)
Routine maintenance activities were reviewed and/or witnessed by the
resident inspection staff to ascertain procedural and performance adequacy
and conformance with applicable Technical Specifications.
The selected activities witnessed were examined to ascertain that, where
applicable, current written approved procedures were available and in use,
that prerequisites were met, that equipment restoration was completed and
maintenance results were adequate.
No violations or deviations were identified.
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7.
Follow-up on Previous Enforcement Actions / Inspection Findings
(92701,92702)
(Closed) UNR 369,370/86-38-01 - Investigate the validity of licensee
statements regarding the transfer of power supplies for shared nuclear
service water (RN) components.
The resident inspectors discussed the
matter with the individual who prepared and presented the RN briefing on
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December 11, 1986, and advised him of the NRC's concerns regarding the
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seriousness of making false statements to the NRC.
The NRC's concerns
were acknowledged and subsequently allayed by written correspondence from
the licensee which satisfactorily clarified the questionable statements.
(Closed) IFI 369,370/86-30-05 - Review the licensee's evaluation of the
source of tritiated water in the sanitary waste system on October 2, 1986.
This matter was reviewed by the Region II Radiological Effluents and
Chemistry Section during the period from November 3-12, 1986. Violations
50-369,370/86-32-02 and -03 were issued as a result of that inspection.
(Closed) IFI 370/86-35-01 - Review the licensee's investigation of the
loss of power to 6900 volt switchgear 2TA on November 20, 1986.
On that date, Construction Maintenance Division (CMD) technical support
personnel were performing a preliminary field survey of a nuclear station
modification (NSM) which would add three new load centers to the shared
600 VAC power system. As part of this modification, CMD craft personnel
had pulled cables to the top of 6900 volt switchgear cubicle 2TA11 for
connection to a current transformer inside.
CMD technical support
personnel were investigating to determine if the current transformer could
be relocated from the bottom to the top of the cubicle where the cables
would enter.
A CMD technical specialist initially went to the front of switchgear
cubicle 2TA11 which was labeled as a spare cubicle. He observed neither
status light (red or green) was illuminated indicating there was no
control power to the cubicle.
He also determined the breaker inside had
been racked out. He, went to the back of the cubicle, removed the cover,
and found the curr911t transformer at the bottom of the cubicle and a
potential transformer at the top. The potential transformer was labeled
as a " Normal Source POT Transformer", and the technical specialist assumed
it was associated with the spare cubicle.
Unaware the potential trans-
former was actually associated with the normal incoming breaker for
6900 volt bus 2TA, he pulled open the transformer door and consequently
de-energized the potential transformer.
The normal incoming breaker
immediately tripped on undervoltage and incoming power to bus 2TA was
lost. Reactor Coolant Pump 2A, powered by bus 2TA, began coasting down
and thc reactor tripped on low reactor coolant system flow.
The CMD technical specialist had nine years of electrical experience in
the nuclear industry and took precautions to ensure there was no control
power to the cubicle and that the breaker was racked out.
However, he
incorrectly assumed the potential transformer in the top of switchgear
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cubicle 2TA11 was only associated with that cubicle. This personnel error
was mitigated by the fact that the potential transformer was not adequately
labeled and that. Design Engineering personnel had incorrectly designated
in .the NSM that the cables enter the cubicle through the top instead of
the bottom where the current transformer was located.
Because the NSM
was being implemented with the unit on-line, the location of the cables
led the CMD technical specialist to believe the potential transformer
was not energized.
The licensee has placed improved labels and warnings in the potential
transformers for the 6900 volt and 4160 volt buses, and the incident was
reviewed with CMD staff and craft personnel. The Station Manager has also
issued a memorandum to all Nuclear Production Department and CMD personnel
directing them to obtain proper permission prior to opening any electrical
equipment for inspection. This IFI is considered closed.
No violations or deviations were identified.
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