ML16148A823
| ML16148A823 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 08/17/1993 |
| From: | Binoy Desai, Harmon P, Lesser M, Poertner W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML16148A822 | List: |
| References | |
| 50-269-93-21, 50-270-93-21, 50-287-93-21, NUDOCS 9309070262 | |
| Download: ML16148A823 (9) | |
See also: IR 05000269/1993021
Text
RE4
UNITED STATES
NUCLEAR REGULATORY COMMISSION
REGION II
101 MARIETTA STREET, N.W.
ATLANTA, GEORGIA 30323
Report Nos.: 50-269/93-21, 50-270/93-21 and 50-287/93-21
Licensee:
Duke Power Company
422 South Church Street
Charlotte, NC 28242-0001
Docket Nos.: 50-269, 50-270, 50-287, 72-4
License Nos.: DPR-38, DPR-47, DPR-55, SNM-2503
Facility Name: Oconee Nuclear Station
Inspection Conducted: June 27 - July 24, 1993
Inspector:
2q
tf
k P. E. Harmon, Senior Resident Inspector
Datt Signed
Y B. B Desai, Resident Inspector
Date Signed
- W. K.
rtner, Resident Inspector
Da
Signed
Approved by.
-//9 3
M. 5. esser, Section Chief
Date Signed
SUMMARY
Scope:
This resident inspection was conducted in the areas of plant
operations, surveillance testing, maintenance activities, Keowee
issues, inspection of open items, and review of licensee event
-reports.
Results:
One violation was identified involving an inadequate modification
procedure. The installation instructions and post modification
testing were inadequate and allowed valve 2RC-4 to be rewired with
the open indication light in the safe shutdown facility
disconnected. The modification was implemented in 1990.
9309070262 930818
PDR ADOCK 05000269
G
REPORT DETAILS
1.
Persons Contacted
Licensee Employees
- H. Barron, Station Manager
S. Benesole, Safety Review Manager
- K. Chea, Instrument and Electrical Section Manager
D. Coyle, Systems Engineering Manager
- J. Davis, Safety Assurance Manager
T. Coutu, Operations Support Manager
B. Dolan, Manager, Mechanical/Nuclear Engineering
W. Foster, Superintendent, Mechanical Maintenance
J. Hampton, Vice President, Oconee Site
D. Hubbard, Component Engineering Manager
- H. Lefkowitz, System Engineer
C. Little, Superintendent, Instrument and Electrical (I&E)
M. Patrick,. Regulatory Compliance Manager
B. Peele, Engineering Manager
- S. Perry, Regulatory Compliance
- G. Ridgeway, Operations
- K. Rohde, Electrical Engineer
G. Rothenberger, Operations Superintendent
R. Sweigart, Work Control Superintendent
Other licensee employees contacted included technicians, operators,
mechanics, security force members, and staff engineers.
NRC Resident Inspectors
b
Harmon
l
Poertner
B. Desai
NRC Personnel
W. Miller
- Attended exit interview.
2.
Plant Operations (71707)
a.
General
The inspectors reviewed planteoperations throughout the reporting
period to verify conformance with regulatory requirements,
Technical Specifications (TS), and administrative controls.
Control room-logs, shift turnover records, the temporary
modification log and equipment removal and restoration records
were reviewed routinely. Discussions were conducted with plant
operations, maintenance, chemistry, health physics, instrument &
S electrical (I&E), and engineering personnel.
2
Activities within the control rooms were monitored on an almost
daily basis.
Inspections were conducted on day and night shifts,
during weekdays and on weekends. Inspectors attended some shift
changes to evaluate shift turnover performance. Actions observed
were conducted as required by the licensee's Administrative
Procedures. The number of licensed personnel on each shift
inspected met or surpassed the requirements of TS. Operators were
responsive to plant annunciator alarms and were cognizant of plant
conditions.
Plant tours were taken throughout the reporting period on a
routine basis. During the plant tours, ongoing activities,
housekeeping, security, equipment status, and radiation control
practices 'were observed
b.
Plant Status
Unit 1 operated at power during the entire reporting period.
Unit 2 commenced the reporting period in a power escalation from a
scheduled refueling outage and operated at power during the
remainder of the reporting period.
Unit 3 operated at power during the entire reporting period.
c.
Unit 2 Loss of Seal Injection
On June 30, 1993, at approximately 10:30 a.m., the Unit 2 control
room operator received a call from maintenance personnel
indicating that the packing gland stud for valve 2HP-64, reactor
coolant pump 2A1 seal injection throttle valve, had broken during
maintenance activities to adjust the packing gland. Approximately
two minutes later the packing blew out of the valve, resulting in
a contaminated seal injection system leak of approximately 25 gpm
into the auxiliary building and a subsequent contamination of two
workers in the area. The operators in the control room entered
abnormal operating procedure AP/2/1700/14, Loss of Normal Makeup
or Letdown. The operators isolated seal injection to all four
reactor coolant pumps and secured and isolated high pressure
injection (HPI) pump 2B to terminate the leakage. The RCS leak
was effectively terminated at approximately 11:00 a.m.
The
licensee determined that approximately 550 gallons of water had
spilled into the auxiliary building due to the packing leak from
During the event the operators increased component cooling water
flow to the reactor coolant pump seals and stationed an operator
to monitor seal temperatures and flows until seal injection could
be reestablished. Seal temperatures increased approximately 30
degrees and stabilized. The licensee replaced the broken packing
gland stud and established normal reactor coolant pump seal
injection at approximately 10:38 p.m.
3
The licensee made a four-hour nonemergency event notification to
the NRC operations center at 12:58 p.m. The notification was made
because the licensee started the 2A HPI pump prior to securing and
isolating the 2B HPI pump. The licensee's initial interpretation
was that a manual engineered safety features actuation had
occurred when the second HPI pump was started. The licensee later
determined that the event was not reportable and retracted the
notification on July 20, 1993, after discussions with the NRC.
The licensee plans to submit a special report describing the event
and subsequent actions.
The licensee sent the failed studs to the materials lab for a
failure analysis. Preliminary results indicate that the stud
failure was induced by hydrogen embrittlement possibly caused by
an inadequately heat-treated cadmium-plated stud. Additionally,
there are indications that misalignment may result when the
packing is tightened. The licensee is still reviewing this item
and has initiated the problem investigation process to resolve and
document the problem.
d.
Unit 3 Low Pressure Service Water Pump Failure
On June 30, 1993, at 4:11 a.m., low pressure service water (LPSW)
pump 3A tripped during normal operation while energized and
supplying flow to the Unit 3 LPSW system.
LPSW pump 3B was
available for operation during this event.
Concurrent with the
trip at 4:11 a.m. several alarms were received in the Unit 3
control room and a momentary dimming of the control room lighting
occurred. The control room operators observed that the LPSW
header pressure low alarm was illuminated and that the 3A LPSW
pump had tripped. The operators immediately started the 3B LPSW
pump to restore flow and dispatched a non-licensed operator (NLO)
to the turbine building to investigate the 3A LPSW pump trip. The
NLO found the 3A LPSW pump motor discolored and the power leads
separated from the motor. The NLO also found the pump motor
breaker tripped from an instantaneous overcurrent on the X phase.
The licensee declared the 3A LPSW pump inoperable and commenced
preparations to replace the pump motor with a spare motor. -With
the 3A LPSW pump inoperable the licensee entered a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />
limiting condition for operation (LCO). The licensee replaced the
3A LPSW pump motor and returned the pump to service at 11:46 p.m.
the same day.
The licensee determined that the 3A LPSW pump failed because of
pump motor winding insulation breakdown, which caused a short on
the X phase motor winding. The 3A LPSW motor had been installed
during initial plant construction and had not shown signs of
excessive degradation or wear prior to failing.
Se.-
Pressurizer Block Valve Open Indication not Available in the Safe
Shutdown Facility.
04
On June 30, the licensee determined that valve 2RC-4, pressurizer
relief block valve, had not been stroked from the safe shutdown
facility (SSF) before Unit 2 was returned to operation from the
scheduled refueling outage. PT/2/A/600/24, SSF Valve Control
Transfer Verification, was performed prior to restart of the unit;
however, the procedure step requiring that 2RC-4 be cycled from
the SSF control room contains a caution statement that the step
should not be performed if the pressurizer PORV is being utilized
as the low temperature overpressure requirement. Based on this
statement 2RC-4 was not cycled from the SSF control room. There
was nothing in the procedure to ensure that valve 2RC-4 is stroked
prior to startup.
While performing the PT on June 30 the operators noted that the
open indication light for 2RC-4 was not illuminated when power was
transferred to the SSF.
2RC-4 valve position indication at the
SSF is available only when the valve is powered through the SSF
control room. A work request was written to investigate why the
valve open indication light was not illuminated. Subsequent to
the restart of the unit the licensee determined that the valve
open light was not wired. The valve had been rewired in 1990 for
a torque switch bypass modification and the open indication had
been inadvertently deleted.
The inspectors reviewed the modification package for the torque
switch bypass modification and held discussions with design
engineering. Procedure TN/2/A/2622/01/CL5, Torque Switch Bypass
Modification for Valves 2HP-115, 2AS-102, 2MS-47, and 2RC-4,
implemented the design modification that deleted the valve open
indication in the SSF. The procedure was inadequate because the
modification rewired valve 2RC-4 and deleted the valve open limit
switch contacts without instruction to install the required jumper
to provide indication in the safe shutdown facility. The
engineering department was aware that jumper installation was
required and the jumper was indicated on the wiring diagrams.
However, the modification package did not contain instructions to
install the jumper. The modification was implemented and tested
in October 1990 and the post modification testing did not reveal
that the valve was wired incorrectly. The inspectors concluded
that multiple opportunities existed to either prevent or detect
the modification error. The failure to provide adequate
instructions to perform the torque switch bypass modification on
valve 2RC-4 is identified as Violation 270/93-21-01: Inadequate
Modification Procedure.
The licensee evaluated the operability of valve 2RC-4 with the
open indication light not wired and determined that the valve
could still perform its intended function. The licensee is
developing a procedure for installing the required electrical
jumper and cycling the valve from the SSF control room. The
licensee has initiated the problem investigation process and plans
5
to revise PT/2/600/24 to require that valve 2RC-4 be operated from
the SSF control room every refueling outage.
One violation was identified.
3.
Surveillance Testing (61726)
Surveillance tests were reviewed by the inspectors to verify procedural
and performance adequacy. The completed tests reviewed were examined
for necessary test prerequisites, instructions, acceptance criteria,
technical content, authorization to begin work, data collection,
independent verification if required, handling of deficiencies noted,
and review o'f completed work. The inspectors witnessed the tests, in
whole or in part, to verify that approved procedures were available;
test equipment was calibrated; prerequisites were met; tests were
conducted according to procedure; test results were acceptable; and
systems restoration was completed.
a.
MP/1/A/2000/33, Unit 1 Electro Mechanical Relay ACB Trip test.
This procedure prescribes a quarterly test on the electro
mechanical trip circuitry for Keowee Unit 1 air circuit breakers
(ACBs) 1 and 3. The inspectors reviewed the completed procedure
and verified that the acceptance criteria were met.
b.
PT/O/A/0400/05, SSF AuxiliaryService Water Pump Test. This
quarterly pump test is required by ASME Section XI and Technical
Specification 4.20.1. The inspectors witnessed the test
performance and verified that the acceptance criteria were met and
were in accordance with the licensee's inservice inspection
program.
No violations or deviations were identified.
4.
Maintenance Activities (62703)
Maintenance activities were observed and/or reviewed during the
reporting period to verify that (1)
work was performed by qualified
personnel, and (2) approved procedures adequately described work that
was not within the skill of the trade. Activities, procedures, and work
requests were examined to verify that proper authorization to begin work
was given, provisions for fire were made, cleanliness was maintained,
exposure was controlled, equipment was properly returned to service, and
limiting conditions for operation were met.
WR 38915C, Replace 3A LPSW Pump Motor. The inspectors monitored work
activities in progress and reviewed the post maintenance testing
performed prior to returning the pump to service. The work activities
were conducted proficiently and expeditiously.
No violations or deviations were identified.
5.
Keowee Issues
6
The inspector verified that procedural guidance was available for
operators at the Keowee Hydro Station covering emergency and off-normal
situations. Written procedures for abnormal station operations were not
available during the loss of offsite power event of October 19, 1992.
Abnormal Procedure AP/O/A/2000/001, Keowee Station Natural Disasters,
issued January 30, 1990, covers tornados and flooding. This procedure
was the only emergency or abnormal procedure available at the time of
the event.
Abnormal Procedure AP/0/2000/002, Keowee Station Emergency Start, issued
February 23, 1993, covers emergency starts, abnormal alignments, and
failures of the Keowee station to provide emergency power as designed.
This guidance includes verification of proper operation and alignments,
actions to manually align and start equipment, and notification to the
Oconee control room and Keowee technicians if actions taken are
unsuccessful.
Included in this procedure are instructions for the
Oconee control room to dispatch an Oconee operator to the Keowee station
to align the "Local-Remote" switch on the Keowee panel to "Remote" if
the Keowee operator is unable to start the Keowee units during emergency
situations. Transferring the controls to Remote allows operators to
manually start the Keowee units from the Oconee control room.
6.
Inspection of Open Items (92701) (92702)
The following open items were reviewed using licensee reports,
inspection record review, and discussions with licensee personnel, as
appropriate:
a.
(Closed) Violation 269/92-23-01: Containment Isolation Valve
Found Open. The licensee responded to this violation by letter
dated November 18, 1992. Licensee Event Report (LER) 269/92-13
was.also submitted to the NRC. The inspector reviewed the
corrective actions stated in the LER as well as the violation
response. Based on the inspector's review of the actions
pertaining to LER 269/92-13 as described in paragraph 7.a of this
report, this item is closed.
b.
(Closed) Unresolved Item 269,270,287/92-23-02: Keowee Single
Failure Criteria. This item addressed single failure requirements
for the Keowee emergency power sources and power paths. The
electrical distribution system functional inspection (EDSFI)
reviewed the operation and single failure requirements for the
Keowee units and emergency power paths. Based on the EDSFI review
the inspectors consider this item closed.
7.
Review of Licensee Event Reports (92700)
The Licensee Event Reports (LERs) listed in this section were reviewed
to determine if the information provided met NRC requirements. The
inspector considered the adequacy of description, compliance with
Technical Specification and regulatory requirements, corrective actions
7
taken, existence of potential generic problems, reporting requirements
satisfied, and the relative safety significance of each event. The
following LERs were reviewed:
a.
(Closed) LER 269/92-13, Technical Specification Violation Due to
Lack of Containment Integrity Resulting From A Defective
Procedure. Containment isolation valve 1N-107 was discovered in
the open position on September 8, 1992. The valve was immediately
returned to its closed position as required. The valve had been
in the open position since June 1992. A defective procedure was
identified as the root cause of the valve being in an abnormal
position. The inspectors verified that the following corrective
actions were taken to prevent recurrence:
-
OP/1/A/1103/02, RCS Filling and Venting, was revised to
require the valve to be verified closed.
-
OP/1/A/1102/01, Controlling Procedure for Unit Startup, was
revised to prescribe the performance of the containment
integrity checklist after procedures that affect manual
containment isolation valves have been completed.
b.
(Closed) LER 269/92-04, Reactor Trip Results From Low Main
Feedwater Pump Discharge Pressure Due to Management Deficiency.
The reactor trip that occurred on May 8, 1992, was caused by less
than-adequate'training and lack of a task specific procedure. The
inspectors verified the following corrective actions to prevent
recurrence:
OP/1/A/1106/02, Condensate and Feedwater System, was revised
to include guidance on reducing Hotwell level.
-
The Alarm response Manual for Hotwell Level Emergency High
Statalarm (1SA6/C-12) was revised to refer to
OP/1/A/1106/02.
-
The lesson plan for the condensate and feedwater system was
revised to include training on hotwell oscillations.
c.
(Closed) LER 269/92-08, Equipment Failure and Inappropriate Action
Result in the Concurrent Inoperability of Both Onsite Emergency
Power Sources and a Technical Specification Violation. This event
occurred on July 17, 1992. Keowee Unit 1 was out of service for
planned maintenance and Keowee Unit 2 was deemed to be inoperable
when a blown fuse associated with ACB 8 was discovered. Following
the discovery of the inoperability of both Keowee units the
Standby buses were not energized by Lee Gas Turbines within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />
as required by TS.
The blown fuse was eventually replaced and Keowee Unit 2 was
declared operable. The root causes associated with this event
were classified as Equipment Failure and Inappropriate Action.
8
The inspectors verified the following corrective actions
associated with this event.
Keowee's breaker status checklist was revised to include
additional breaker and indicator status for each breaker.
-
OP/O/A/1107/03 was revised to include notification to Lee
Steam Station of the time the gas turbines are required to
be in service; a notification step also was included earlier
in the procedure.
-
Training was given to Lee Steam Station personnel concerning
initiating a start of the second gas turbine if the primary
turbine does not start or trips after initial start.
-
A rounds and turnover procedure was initiated to enhance
monitoring of Keowee Hydro equipment.
Training was given to Keowee personnel on the new Keowee
procedures, checklists, and the time constraints of
Technical Specifications.
-
A root cause analysis was performed on the failed fuse.
Though the results were not conclusive, the licensee decided
to phase out this type of fuse. No target date has been
established.
-
The inspectors reviewed PIP 92-293, which is investigating
the possibility of modifying the circuit associated with
breaker indication.
8.
Exit Interview
The inspection scope and findings were summarized on July 27, 1993, with
those persons indicated in paragraph 1 above. The inspectors described
the areas inspected and discussed in detail the inspection findings.
The licensee did not identify as proprietary any of the material
provided to or reviewed by the inspectors during this inspection.
Item Number
Description/Reference Paragraph
Violation 270/93-21-01
Inadequate Modification Procedure
(Paragraph 2.e).