ML20126B852
| ML20126B852 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 12/14/1992 |
| From: | Gagliardo J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | |
| Shared Package | |
| ML20126B835 | List: |
| References | |
| 50-298-92-22, NUDOCS 9212220245 | |
| Download: ML20126B852 (15) | |
See also: IR 05000298/1992022
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APPENDIX B
U.S. NUCLEAR REGULATORY COMMISSION
REGION IV
Inspection Report: 50-298/92-22 Operating License: DPR-46
Licensee: Nebraska Public Power District
P.O. Box 499
Columbus, Nebraska 68602-0499
Facility Name: Cooper Nuclear Station
Inspection At: Brownville, Nebraska
Inspection Conducted: October 4 through November 14, 1992
Inspectors: R. A. Kopriva, Senior Resident Inspector
W. C. Walker, Resident Inspector
J. M. Keeton, Operator Licensing
Approv ' #o yL 2. _['1 '
. Gagliardo,' liTeT7T jects section C at
Inspection Summar_y
Areas Inspected: Routine, unannounced inspection of onsite response to
events, operational safety verification, surveillance observations, followup,
and onsite review of licensee event reports.
Resulu:
e Overall, the licensee operated the facility safety (paragraphs 2 and
3.5).
- The licensee's evaluation and corrective actions to address the water
hammer event in Residual Heat Removal System B on October 22,-1992, were
prompt and appeared to be good (paragraph 2),
o Housekeeping was improving. Licensee management was addressing this
issue (paragraph 3.2). ;
e A compressed gas cylinder was not properly controlled on the refueling -
floor for an extended period of time. This is a violation
(paragraph 3.2),
e One example of improper control of visitors was identified. This is a
violation (paragraph 3.4).
- Surveillance tests were performed well. The licensee personnel involved
were knowledgeable of the tasks required and their actions were good
(paragraph 4.3).
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- The maintenance activity to repair and inspect the faulty diesel
generator fuse holders was good (paragraph 5.1).
s The licensee appropriately addressed, from a safety perspective, the use
of a process can in the spent fuel pool (paragraph 6.3).
- Licensed operator training weaknesses were observed in command, control,
and communications; however, the licensee was aware of the problems and
was actively pursuing their corrective actions program. The simulator
evaluators were very professional and exhibited good evaluation skills.
Examination material was very good and in accordance with the standard.
The licenset operators appeared to be safety-conscious and competent
(paragraph 6.5).
Summar.y of Inspection Findings:
e Violation 298/9222-01 was opened (paragraph 3.2).
e Violation 298/9222-02 was opened (paragraph 3.4).
- Inspection Followup Item 298/9034-02 was closed (paragraph 6.1).
e Unresolved Item 298/9219-01 was closed (paragraph 6.2).
e Unresolved Item 298/9219-02 was closed (paragraph 6.3).
- Licensee Event Reports92-008, 92-012, and 92-013 were closed
(paragraph 7).
Attachments (and/or Enclosures):
e Attachment 1 - Persons Contacted and Exit Meeting
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DETAILS
1 PLANT STATUS $
At the beginning of this inspection period, the plant was operating at
53 percent power and in single-loop operation. On October 1, 1992, Reactor
Recirculation Motor-Generator Set B had tripped due to a faulty resistor and
two faulty diodes. The components were replaced and the motor-generator set
was restarted. The unit returned to full power on October 5. At the end of
this inspection, the plant was operating at 100 percent power.
2 ONSITE RESPONSE TO EVENT (93702)
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Residual Heat Removal System B Inoperable
On October 22, 1992, Residual Heat Removal System B was declared inoperable
during performance of Surveillance Procedure 6.3.5.1, "RHR Test Mode
Surveillance Operation Quarterly Inservice Test," Revision 35.
During the surveillance, Residual Heat Removal Pump B was run, determined to
be acceptable, and shut down. Pump D was then aligned according to the
procedure, which took approximately 5 minutes. Upon the starting of Pump D, a
loud noise was heard. The licensee investigated the source of the noise and
located a leak on the 958 foot elevation of the reactor building, at the
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flange for Pressure Maintenance System Check Valve 19. The check valve was
located in a 4-inch line which is part of the auxiliary ccndensate system,
which provides pressure maintena e o r the residual heat removal system.
Approximately 50 gallons of wat e had leaked out of the system into the
reactor building. Licensee empsoyees bserved that the bonnet gasket on Check
Valve 19 was unseated. They pr3ce h to walk down the remainder of the
pressure maintenance system and (Qsm ed two pipe supports which had been
deformed from-the event and als seve al pipe hangers which were misaligned.
The licensee determined that the n. <et faih re and pipe damage were caused by
a water hammer.
The licensee reviewed past water hammer events that have occurred in boiling
water reactors, conducted system walkdowns, and assov.ed the impact the water
hammer had on the residual heat removal system. The licensee repaired the
pipe supports that were damaged and the check valve which was found to be
I leaking due to the ';ent. The check valve was functionally -tested and found
to be satisfactory. Documentation was provided which showed that the event
had not compromised the system pressure boundary integrity in its repaired
configuration.
The licensee determined that the event was caused by valving out the pressure
maintenance system when switching over from Pump B to Pump D during the
surveillance test. A procedure change had been made which requires that the
pressure maintenance system remain in service during pump changeover. The
L inspectors reviewed the licensee's corrective actions and found them
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appropriate.
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Conclusions
The licensee's evaluation and corrective actions were prompt and appeared to
be good.
3 OPERATIONAL SAFETY VERIFICATION (71707)
3.1 Control Room Observations
The inspectors observed operational activities throughout this inspection
period to verify that proper control room staffing and control room
professionalism were maintained. Control room shift supervisor log book, tag
out log book, and control room balance-of-plant log book entries were reviewed
to verify that appropriate entries were made. The licensee's control of these
activities was good.
3.2 Plant Tours
The inspectors toured various areas of the plant to verify that proper
housekeeping was being maintained. Housekeeping was found to be improving,
but su4e areas remained where additional improvement was needed. The
licensee's increased efforts for improving housekeeping were evident and
management was continuing to review this activity.
On October 5, the inspectors found an unsecured, wheeled fire extinguisher in
the reartor building on the 958-foot elevation and questioned the licensee as
to what effect a seismic event would have on the unsecured fire extinguisher.
Approximately 15 feet separated the fire extinguisher cart from Fuel Pool
Cooling Instrument Rack 25-16 containing essential equipment. The licensee ;
performed a seismic analysis to determine whether the subject fire
extinguisher could have interacted with essential equipment. The analysis
concluded that it would be unlikei) that the extinguisher would topple during
a seismic event. However, if it did tip over, there was no essential
eauipmerit located where it could interact with the extinguisher.
As a conservative measure, the licensee secured the extinguisher. In
addition, the licensee reviewed six other wheeled fire extinguisher locations
within the plant to determine possible interaction of those extinguisbers with
essential equipment. The licensee concluded that no concerns existed with the
six other wheeled fire extinguishers. The inspectors reviewed the licensee's
actions and considered them to be appropriate.
On October 6,1992, during a walkdown of the reactor building, the inspector
identified a gas cylinder in the northwest quadrant of the refueling floor j
which was roped to the two-wheel cart used for transporting the gas cylinder.
The gas cylinder was not secured to a fixed restraint, the cart was not a
wheeled cart of approved design for storage or use, and the wheels of the cart
were not blocked or locked. At the time of discovery the inspector could not
identify a use for the cylinder or the status of the cylinder (i.e., whether
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it was full or empty). Under certain conditions, the cylinder could become a
missile and damage equipment or personnel on the refueling floor or equipment l
in the fuel pool. ;
The licensee determined that the gas cylinder was helium and that it had been
used on April 11 to leak test the reactor pressure vessel . surveillance
specimen shipping cask in accordance with Special Procedure 92-022. The
special procedure did not include specific precautions or instructions for-
handling, storage, or removal of the gas cylinder- The licensee removed the .
gas cylinder from the refueling floor. The protective cap was in place on the
cylinder and it was partially, if not completely, depressurized.
Title 10 CFR Part 50, Appendix B, Criterion V, states that activities
affecting quality shall be prescribed by documented instruction, 3rocedures,
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or drawings of a type appropriate to the circumstances and shall ae
accomplished in accordance with these instructions, procedures, or drawings.
Procedure 0.7, Revision 8, " Flammable, Combustible, and Chemical Material
Control," paragraph-8.3.2.2.0, states that, during storage and use, gas
cylinders shall be individually secured to a fixed suppor.t by a restraint, and
paragraph 8.3.2.3 states that use of wheel-mounted carts of approved design
are permitted for certain uses of gas cylinders. .The helium gas cylinder had
been on the refueling floor since approximately April 11 and on October 6 was
not secured to a fixed support and was not on a wheel-mounted cart of approved
design. This is a violation.(298/9222-01).
3.3 Radiological Protection Observations
The inspectors verified that selected radiological protection activities were
in conformance with facility policies, procedures, and regulatory
requirements. Radiation and/or contaminated areas were properly posted and
controlled.
3.4 Security Program Observations
On October 5, the inspectors observed a repairman, with a visitor's badge, on
the_ first floor of the administration building, in a room with two separate
access points, and he was not within the line of sight of his escort. One
access point would have allowed the repairman to leave the-work area-unseen by !
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the escort and obtain access to other areas within the protected area. ..The-
inspectors asked the repairman about his escort. The repairman thought he
could identify his escort, but was uncertain where the escort was. The
inspectors located the escort. The escort had assumed that the access door
leading from the work room to other areas within the plant was closed. After o
being questioned by the inspectors,=the door was closed. However, there was ,
no way to lock this door which would prevent the repairman from exiting :
unobserved. The inspectors promptly reported the situation ~to station !
security and a security officer was dispatched to review the situation. l
The inspectors reviewed the licensee's escort training and training
documentation. The escort training lesson plan and Visitor / Tour Station l
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Access Procedure 1.15 provided instructions to escorts to maintain positive
control of visitors. The individual responsible for escorting the repairman
had received the training. The licensee counseled the individual responsible
for escorting the visitor to ensure understanding of proper escort procedures,
On October 5, Security Event Report 92-224 was completed, which outlined the
event details. immediate corrective actions included providing an escort for
the repairman and sending a security guard to the incident location to review
the situation. The licensee also counselled the individual, emphasizing
instructions regarding visitor control requirements. The licensee was
reviewing the procedures to determine their adequacy, and long-ierm corrective
actions had not been established at the end of this report period.
Title 10 CFR 50.34(c) requires that each application for a license to operate
a production or utilization facility shall include a physical security plan.
The Cooper Nuclear Station Physical Security Plan, Section 1.5.2, requires
that escorts exercise and maintain control of their visitors at all times.
Cooper- Nuclear Station Operations Manual, Plant Services Procedure 1.15, ,
" Visitor / Tour Station Access," Revision 8, Section 4.2.1, states that an
escort is responsible to exercise and maintain control of the visitor at all
times, The failure to exercise and maintain control of a visitor (i.e., an
individual not authorized by the licensee to enter protected areas without an
escort) while the visitor was working within the protected area on October 5,
1992, is a violation of NRC requirements (298/9222-02).
3.5 Conclusions
- Overall, the licensee operated the facility safely,
- Housekeeping was improving. Licensee management was addressing this
issue.
- A compressed gas cylinder was not properly controlled on the refueling
floor for an extended period of time. This is a violation.
- One example _of- improper control of visitors was identified. This is a
violation.
-4 SURVEILLANCE 0BSERVATIONS (61726)
4.1 Undervoltage Relays and Rela _y Timers Functional Test
On October 16, 1992, the inspector observed the performance of Surveillance-
Procedure 6.2.2.1.10. "4160V Buses If and 1G Undervoltage Relays and Relay
Timers Functional Test," Revision 18.
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Operators appeared to be following the surveillance procedure both locally and
in the control room. Good communications were noted between the control room
operators and individuals performing the surveillance. In reviewing the
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procedures the inspector noted that proper signatures and approvals were .
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evident. During the surveillance the inspector observed that the conditions
inside the 4160V breaker cabinets were clean. ;
4.2 Reactor Core isolation Coolina Steam line Hiah Flow Calibration and
Functional Test
On October 28 the inspectors observed performance of Surveillance
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Procedure 6.2.2.6.1 " Reactor Core Isolation Cooling Steam Line High Flow
Calibration and Functional Test," Revision 21. The inspector observed an-
instrument mechanic performing the calibration of the differential pressure
switches which are used to monitor reactor core isolation cooling steam line
fl ow. The instrument mechanic was adhering to the procedure and-m..intained
good communications with the control room operators-throughout the
surveillance. The instrument mechanic was conscientious in complying with
good radiological practice as he routinely changed protective gloves during
his manipulation of the valves associated with the differential pressure
switches. The surveillance was completed satisfactorily with no anomalies
encountered.
4.3 Conclusions
The surveillances observed were performed well. The licensee personnel:
involved were knowledgeable of the tasks required and executed these tasks
sufficiently to comply with the procedures. The inspectors found the licensee
actions, as they pertained to these surveillances, to be good,
5 MAINTENANCE OBSERVATION (62703)
On November 10, 1992, during a routine surveillance run of Emergency Diesel
Generator 1, it was noted that.the air start solenoid to_one bank of air
cylinders had not actuated. Upon'further investigation, the licensee found
the fuse holder for that solenoid to be loose.
The inspectors observed the corrective: maintenance activity to repair the fuse
holder and the panel inspections-to check other fuse holders that may have-
experienced similar problems. The licensee did not -identify any addition
examples.of this deficiency. The inspectors verified ~that the workers *
obtained proper authorization to perform the work, _that control room operators
were cognizant.of the maintenance activity, that workers followed'the
maintenance instructions, and that appropriate safety. precautions were taken
for work in energized panels. The inspector observed the postmaintenance
functional check of the solenoid and verified proper operation. The
inspectors noted that the electrical cabinets were clean. No unacceptable-
. conditions were identified.
5.1 Conclusion
The maintenance activity to repair and inspect _ i - >olders was good.
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6 FOLLOWUP (92701)
6.1 (Closed) Inspection Followup Item 298/9034-02: Entry into a Technical
Specification Limittna Condition for Operation During the Performance of
Surveillance Testing
The resident inspectors reviewed a licensee memorandum dated April 17, 1991,
which outlined proposed technical guidance and reflected existing policy on
the subject of entering Technical Specification. action statements during the
performance of surveillance testing. The licensee had identified several
cases where procedures could disable a safety function during the performance
of a routine test. As a result, several procedures were revised. Certain
Technical Specification surveillance requirements have been amended to change
the test frequency to allow the performance of the st/veillance procedures
during refueling shutdowns instead of performing these at power.- Also, a
Technical Specification amendment eliminated the testing of certain systems
and components following the failure of a redundant system or component, a
practice which could result in the removal from service of the only operable
system or component. The licensee has taken further action to address the
issue of operability during the performance of surveillance procedures by
organizing a task force to identify additional required changes in the
surveillance program and Technical Specifications.
6.2 _(Closed) Unresolved Item 298/9219-01: Implementina Organizational Change
without Having Amended the Technical Specifications
The licensee implemented a site reorganization on July 20, 1992, and had not
revised their Technical Specifications to reflect the changes in the
reorganization. On October 8, the licensee submitted their-Technical
Specification amendment to the Commission. Inspectors reviewed, for the time
between reorganization and submittal of the amendment, the person assigned
full. time responsibility for the operation of the facility as specified in
Technical Specification 6.1.1. The inspectors concluded that the licensee met
Technical Specification 6.1.1 during this time period.
6.3 LClosed) Unresolved item 298/9219-02: Potential Failure to Perform a
10 CFR 50.59 Review for Eauipraent Placed on Ten of Empty Spent Fuel Racks
On September 25, 1992, during a plant walkdown, the inspector identified a
process can located on top of empty spent fuel racks. The process can was
used as part of the licensee's spent fuel pool cleanup project. The
inspectors questioned whether a 10 CFR 50.59-evaluation for the process can
pertaining to its location on the spent fuel racks had been performed.
The process can was 2 feet in diameter by 4 feet long with a fully loaded
weight of.approximately 800 pounds. An engineering evaluation had been
performed prior to placement of the can on the spent fuel racks, to ensure
that the racks would handle the fully loaded weight of the can. Also, the
licensee considered the possibility of damaging fuel assemblies should a
seismic event or industrial accident happen. Interaction between the can and
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spent fuel assemblies was not deemed to be credible _because of the 20-foot
distance between the can and the storage racks containing spent fuel.
The licensee concluded that the calculated design basis seismic force would
overcome the friction between the process can and the spent fuel rack before
tipping the can, therefore, the can would remain upright-and horizontal
movement would be limited because of the oscillating nature of a seismic
event. lhe can was submerged in water which had a dampening effect on any
movement of the can. If the process can were to slice or roll far enough to
impact fuel bundles, damage to the fuel assemblies would not be expected. The
fuel manufacturer estimated that it would take 250 foot-pounds of downward
impact loading to damage one fuel rod. further, the licensee's_ Refuel
Accident Radiological Effects Calculation (No, NEDC 88-171), which assumes
111 rods to be broken, concludes that the resulting lifetime-thyroid and whole
body dose would be less than 1 percent of the NRC 10 CFR Part 100 reactor
siting criteria. The relationship between a vertical drop loading and a side
loading (assuming the process can moves horizontally) would not be one to one.
The 800 pound process can would have to free-fall approximately 34 feet- to
damage 111 fuel rods. This amount of energy would not be attainable for the
configuration and controls the licensee had in place for the process can. If
the can were to move in a direction away from the spent fuel, it could
possibly fall into the cask pad area of the fuel pool. This accident would be
significantly less severe than the shipping cask drop accident analyzed in
Burns & Roe Calculation 2520-02.
Concerns for loose parts-(i.e., if the can were to topple over) falling into
the spent fuel pool or even potentially being transported into the reactor
have been addressed in bounding analysis previously completed for the site.
The licensee concluded that, with the procedures being used, the location of
the process can in the spent fuel pool, and the previous analysis performed,
all safety questions / concerns pertaining to the process can had been
addressed.
The inspectors concluded that the licensee's evaluation of the use of the
process can was appropriate.
6.4 Licensed Operator Requalification Program Evaluation
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On November 4 and 5, 1992, the resident inspector and a Region-based inspector
observed some requalification examinations, interviewed on-shift' supervisors,
and reviewed training and testing material. . Also, the licensed operators were
observed during the simulator examinations to determine if they were
conducting activities in a manner conducive to protection of the public health
and safety.
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The following previously identified weaknesses (from NRC Inspection
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Report 50-298/9102) were specifically addressed either by direct observation,
interviews, or by reviewing training program records:
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e Crew command, control, and communication
e Adequacy of simulator scenarios
e Operators' ability to establish shutdown cooling
e Operators' ability to diagnose conditions
Some communications weaknesses were seen during this inspection:
e During one scenario, the supervisor directing panel activities was not
concise in his directives. A lack of uniformity in communication among
crews was seen,
o During another scenario, a supervisor directed an operator to establish
torus spray. The operator could not get torus spray started and did not
inform the supervisor, who assumed that the torus was being sprayed.
The communications problems observed were compensated by actions of the
operators such that safety problems did not develop and mitigation strategies
were not degraded. The facility managers stated that initiatives were in
progress to improve communications. This was primarily being done in the
evaluation sessions during the requalification training. There was no formal
classroom presentation geared to defining a communications policy.
Training Guide NTG 318, " Command and Control" and operations directive, "CNS
Communications," were developed to address command and control. However,
there did not appear to be a formal method to define -their interrelationship.
Command and control training had been incorporated into the evaluation
sessions during requalification training, but there were no formal classroom
presentations scheduled to address this area.
A review of the training and testing material used for this requalification
cycle showed that the material was current-and that mechanisms were in place
to update the material. The simulator scenarios developed for this. evaluation
were in accordance with the guidelines stated in NUREG-1021, " Operator-
L.icensing Examiner Standards," Revision 7. Critical task identification and
task standard definitions were very good. A review of the graded written-
examinations indicated that they were developed based on the sample-plan' and
that they discriminated at the proper level.
During the simulator scenarios and walkthroughs, conditions existed that
required establishing shutdown cooling. The operators were able to perform
all operations necessary to ' accomplish shutdown cooling. No errors were
noted.
The licensed operators observed during the simulator and walkthrough
examinations demonstrated the ability to diagnose events and conditions. No.
errors were observed.
The facility evaluators conducted the dynamic simulator and walkthrough
examinations professionally and in accordance with the standards. The
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evaluators were able to function autonomously without management interference
or visible constraints. During simulator evaluation sessions that were ,
observed, the lead examiner elicited full participation from all evaluators.
Facility evaluations were consistent with their program guidance, and the
licensee took appropriate measures to preserve examination integrity.
Other observations made by the inspectors and connunicated to the licensee
include:
e Shift technical advisor rotation policy and involvement during
requalification examinations was not fully understood by the shift
Crews.
e Simulator difficultly with P-1 printout has contributed to negative
training. Rather than following up when a P-1 was not obtained, the
crew assumed it was a simulator problem and simulated having a. printout.
- At one point during a shift crew scenario, both reactor operators were
behind the control panels at the same time.
e Based on inspectors' observations, the licensee has made progress to
increase operations' sense of ownership in training.
Areas of strength that were identified include:
- Evaluators were very professional and exhibited good evaluation skills,
o Examination material was very good and in accordance with the standard.-
- Licensed operators took a serious professional approach to the annual
evaluation.
Although weaknesses were seen in command, control, and communications, the
licensee was aware of the problems and was actively pursuing their corrective
actions program. The licensed operators appeared to be' safety-conscious and
competent.
6.5 Conclusions
e The licensee appropriately addressed, from a safety perspective, the use
of a process can in the spent fuel pool.
- Licensed operator training weaknesses were observed in command, control,
and communications; however, the licensee was aware of the problems and
was actively pursuing their corrective actions program. The simulator
evaluators were very professional and exhibited good evaluation skills.
Examination material was very good and in accordance with the standard.
The licensed operators appeared to be safety-conscious and competent.
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7 ONSITE REVIEW 0F LICENSEE EVENT REPORTS (92700)
7.1 (Closed) Licensee Event Report 298/92-008: Inoperability of the High
Pressure Coolant Injection System Due to Stem Nut Wear of a Motor-
Operated Valve
This licensee event report documented the licensee's determination that the
high pressure coolant injection valve, HPCI-MOV-58, which is the pump suction
valve from the torus, was not stroking properly. During the running of
Surveillance Procedure 6.2.2.3.4, "HPCI Suppression Chamber and Emergency
Condensate Storage Tank Water Level Calibration and Functional / Functional Test
and Water Initiation," Revision 25, both HPCI-MOV-58 and HPCI-MOV-17,-the pump
suction valve from the emergency condensate storage tank, could have been
closed. The system logic for these two valves is such that one of them should
always remain in an open position to provide suction for emergency core
cooling through the high pressure coolant injection system.
The licensee concluded that, had the high pressure coolant injection system
been required, it would have functioned as designed for as long as 10 minutes
before tripping off on low suction pressure. The most limiting accident
requiring operation of the high pressure coolant injection system is a small
break loss-of-coolant accident and, for accident analysis purposes, high
pressure coolant injection is considered inoperable. The response of the
plant to the small break loss-of-coolant accident has been predicted in~ the
latest accident analysis.
The licensee replaced the worn stem nut and reset the limit and torque switch
settings. The licensee established acceptance criteria for stem nut thread
inspection, but had not yet revised the maintenance procedure. The licensee
committed to provide detailed instructions for performing stem nut inspections
in the Limitorque maintenance procedures. Also, all_ Generic Letter 89-10
safety-related motor-operated valves with rising stems which have original
stem nuts installed are being identified. Following the above activities, a
representative sample of the motor-operated valves identified will have their
stem nuts inspected to determine whether a potential motor-operated valve stem
nut wear problem. exists.
The inspector reviewed the documentation of the completed corrective' actions
and concluded that the licensee's actions were appropriate.
7.2 (closed) Licensee Event Report 298/92-012: Inoperability of Reactor
Core Isolation Coolina Motor-Operated-Valve Due to Water Intrusion into
the Motor Operator
This_ event involved the surveillance testing on_the outboard _ steam supply
isolation valve to the reactor core isolation cooling system. As part of the
surveillance, the outboard isolation valve was closed but failed to reopen
when required. Upon investigation, moisture was discovered in the limit
switch box which caused the valve to not open. A hair-line crack was found in
the flexible conduit installed to protect the wiring between the limit switch
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compartment and the terminal box. This crack was near a steam packing leak
which allowed moisture to enter the conduit line and travel into the limit
- switch box. The inboard and outboard isolation valves were both normally
open. The inboard isolation valve was operable.
The licensee reduced power for ALARA purposes so that entry into the steam
tunnel for repair of the valve could be made safely. The corrective actions
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included drying out limit switch internals and replacing the valve motor
degraded terminal blocks. A tee drain was installed n- the limit switch
compartment cover to provide a drain path for any fF moisture
accumulation, and a shield was installed around the .uit in the immediate
vicinity of the motor-operated valve. The licensee pians to replace the-
cracked conduit during the 1993 refueling outage and to inspect other motor--
operated valve installations where flexible conduit containing motor-operator
leads may be in close proximity to valve packing glands.
The inspectors reviewed the documentation of the completion of the licensee's
corrective actions and concluded that the licensee appropriately addressed
safety.
7.3 (Closed) Licensee Event Report 298/92-013: Error in Limiting Single
Failure Assumption for the Emergency Core Coolina System Performance
Analysis
This event involved the discovery of a nonconservativo assumption in the '
emergency core cooling system performance analysis, under postulated design
basis loss-of-coolant accident conditions. The nonconservative assumption was
that the most limiting single failure was the_ failure-of one low pressure
coolant injection subsystem injection valve. During the licensee's review of
their design basis reconstitution program, they determined several failure
modes existed for the 125-Vdc power system which would result in a more
limiting single failure condition than previously analyzed. The licensee's
immediate corrective action was to. reduce power toward hot shutdown in 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />
and cold shutdown in 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br /> as required by Technical Specifications,-and a
Notification of Unusual Event was declared. Prior to achieving hot shutdown,
a vendor analysis indicated that meeting the design basis for emergency core
cooling systems was possible with certain operating restrictions. An -
- operating restriction of 90 percent power was imposed and remained in effect. ;
until modifications were completed which restored the validity of the original
'
assumptions-used in the emergency core cooling system performance loss-of-
coolant analysis.
On September 14, 1992, the licensee completed Design Change 92-141B which
allowed control of low pressure coolant injection and -reactor recirculation
discharge valves to be independent of the 125-Vdc battery system and, thus,_
not subject to failure due to loss of one 125-Vdc battery system.
The inspector observed changes made to the 250-Vdc control power and verified
documentation for completion of the design change.
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8 MANAGEMENT MEETINGS (30702)
On September 25, 1992, the Region IV Regional Administrator and members of his
staff accompanied the resident inspectors on a site tour and attended a
presentation by the licensee. The licensee presentation included site
communications, quality assurance training, and their deficiency reporting
program, followed by an open discussion between the licensee and the NRC
staff.
On October 1 and 2, the Division Director for the Division of Reactor Projects
was onsite for a site tour and discussions with select members of the .-
licensee's staff.
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ATTACHMENT 1
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1 PERSONS CONTACTED
1.1 Li_censee Personnel
R. L. Beilke, Radiological Support Manager l
'
L. E. Bray, Regulatory Compliance Specialist
R. Brungardt, Operations Manager
M. A. Dean, Nuclear Licensing and Safety Supervisor
J. W. Dutton, Nuclear Training Manager
C. M. Estes, Senior Manager of Operations
J. R. Flaherty, Engineering Manager
R. L. Gardner, Plant Manager
M. D. Hamm,_ Security Supervisor
H. T. Hitch, Plant Services Manager
R. A. Jansky, Outage and Modifications Manager -
E. M. Mace, Senior Manager Site Support
J. H.-Meacham, Site Manager
C. R. Moeller, Acting Technical Staff Manager
S. M. Peterson, Senior Manager of Operations
G. E. Smith, Quality Assurance Manager
M. E. Unruh, Maintenance Manager
R. L. Wenzl, NED Site Engineering Manager
The personnel listed above attended the exit meeting held on November 16,
-1992. In addition to the personnel listed above,_the inspectors contacted
other personnel during this inspection period.
2 EXIT MEETING
An exit meeting was conducted on November 16, 1992. During this meeting, the
inspectors reviewed the scope and findings of this report. The. licensee did-
not identify as proprietary any information provided to,_or reviewed by, the
inspectors.
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