ML16154A835
| ML16154A835 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 10/03/1995 |
| From: | Crlenjak R, Harmon P NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML16154A834 | List: |
| References | |
| 50-269-95-18, 50-270-95-18, 50-287-95-18, NUDOCS 9510180353 | |
| Download: ML16154A835 (16) | |
See also: IR 05000269/1995018
Text
UNITED STATES
NUCLEAR REGULATORY COMMISSION
REGION II
101 MARIETTA STREET, N.W., SUITE 2900
ATLANTA, GEORGIA 30323-0199
Report Nos.: 50-269/95-18, 50-270/95-18 and 50-287/95-18
Licensee:
Duke Power Company
422 South Church Street
Charlotte, NC 28242-0001
Docket Nos.:
50-269, 50-270 and 50-287
License Nos.: DPR-38, DPR-47 and DPR-55
Facility Name: Oconee Units 1, 2 and 3
Inspection Conducted: July 30 - Sept mber 9, 1995
Inspectors:
0
V. t. Harmon, Senior esident Inspector
Date Signed
L. A. Keller, Resident Inspector
P. G. Humphrey, Resident Inspector
L. Wien, Project Manager
Approved by:
_
_
_
__
_
_
_
-
R. V. Clenjak, Chie
Date Signed
Reactor Projects Branch 3
SUMMARY
Scope:
This routine, resident inspection was conducted in the areas of
plant operations, maintenance and surveillance testing, onsite
engineering and plant support.
Results:
In the operations area, the inspectors were concerned with the
number and increased frequency of configuration control errors. A
violation with six examples was identified for inadequate
configuration control.
The inspectors concluded that the large
number of examples of inadequate configuration control represented
a programmatic weakness, paragraph 2.e. Prompt corrective actions
taken by the Unit 3 control room operators following a heater
drain pump trip avoided a reactor trip, paragraph 2.f.
In the maintenance area, concerns were identified regarding the
implementation of a Keowee modification. Concerns included
inadequate planning, lack of management oversight, and lack of
configuration control, paragraph 3.a.(3). The prompt and
comprehensive effort to locate and eliminate a DC ground at Keowee
was identified as a strength, paragraph 3.a.(6).
Enclosure 2
9510180353 951013
PDR ADOCK 05000269
2
In the engineering area, vendor-supplied valve data resulted in a
calculation error for the predicted Low Pressure Injection (LPI)
flow rates during accident conditions. Due to recent
modifications, the LPI systems were operable; however, they were
considered technically inoperable prior to the modifications,
paragraph 4.
In the plant support area, the inspectors reviewed the results of
the licensee's efforts at reducing personnel radiation dose for
the Unit 3 refueling outage. Outage doses were substantially
lower than previous outages, paragraph 5.a. Plant Operating
Review Committee meetings were well organized and placed
appropriate emphasis on safety, paragraph 5.b.
Enclosure 2
REPORT DETAILS
1.
Persons Contacted
Licensee Employees
- E. Burchfield, Regulatory Compliance Manager
T. Coutu, Operations Support Manager
- D. Coyle, Systems Engineering Manager
J. Davis, Engineering Manager
- W. Foster, Safety Assurance Manager
- J. Hampton, Vice President, Oconee Site
D. Hubbard, Maintenance Superintendent
- C. Little, Electrical Systems/Equipment Manager
B. Peele, Station Manager
G. Rothenberger, Operations Superintendent
- J. Smith, Regulatory Compliance
- R. Sweigart, Work Control Superintendent
Other licensee employees contacted included technicians, operators,
mechanics, security force members, and staff engineers.
- Attended exit interview.
Acronyms and abbreviations used throughout this report are identified in
the last paragraph.
2.
Plant Operations (71707)
a.
General
The inspectors reviewed plant operations throughout the reporting
period to verify conformance with regulatory requirements, TS, and
administrative controls. Control room logs, shift turnover
records, temporary modification log, and equipment removal and
restoration records were reviewed routinely. Discussions were
conducted with plant operations, maintenance, chemistry, health
physics, I&E, and engineering personnel.
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 complement of licensed personnel on each shift
inspected met or exceeded 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.
2
b.
Plant Status
Unit 1 operated at or near full power throughout the inspection
period.
Unit 2 operated at or near full power throughout the inspection
period.
Unit 3 operated at full power until August 14, 1995, when it
tripped due to a problem with the control rod drive system. The
unit returned to full power the following day. On August 31,
1995, power was reduced to 76 percent due to an entry into TS 3.7.3 (see paragraph 3.a.(3)). The unit returned to full power on
September 1, but reduced power to 59 percent on September 2, in
order to repair a leak on the 3A Feedwater Pump seal water piping.
The unit returned to full power the following day and continued at
full power throughout the remainder of the inspection period.
C.
Unit 1 Control Rod Drive System Patch Panel Unlocked
On July 8, 1995, at 10:15 a.m., operators discovered the Unit 1
CRD System Patch Panel was unlocked. This panel is required by TS 3.5.2.7 to be locked at all times after confirmation of proper rod
operation and sequence. The licensee entered LCO 3.0, which
requires plant shutdown within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> unless the condition is
rectified and the LCO exited. The licensee determined the panel
lock to be broken, and placed a security guard at the panel at
1:00 p.m. At that time, the LCO was exited. The lock was
repaired at 4:10 p.m.
The Station Manager decided to re-confirm proper rod operation and
sequence by completing procedure IP/1/A/0330/002D, Control Rod
Patch Verification Test. This test was completed satisfactorily
at 9:16 p.m. The decision to perform the verification test was
appropriate and conservative.
This issue will be addressed further during review of associated
LER 269/95-05, Breach of Technical Specification Due To Unlocked
Control Rod Patch Panel, submitted August 7, 1995.
d.
Unit 3 Reactor Trip
Oconee Unit 3 tripped from 100 percent reactor power on August 14,
1995, at approximately 4:45 a.m. The unit tripped on a variable
low pressure/temperature signal resulting from a reactor coolant
system low temperature condition that occurred when the group 5
control rods unexpectedly dropped into the core. The CRD
programmer was suspected of causing the rod drop since the
remaining electrical equipment, unique to the rod group, was
Enclosure 2
- I
3
checked out and no problems were identified. The programmer was
replaced and returned to the vendor for further testing. In
addition, a temporary modification was implemented to monitor the
power supply to the CRD programmer for future evaluations.
The plant responded to the trip appropriately and all systems
performed as expected. The inspectors responded to the unit
following the trip and observed the operator activities in
progress. The operators performed effectively in responding to
the trip and stabilizing the plant.
On the evening of August 14, 1995, the inspectors attended the
PORC meeting. The committee members agreed to restart the unit
subject to the replacement of the programmer. The licensee
decision to allow plant restart was based on the evaluations from
the post trip reviews.
The inspectors reviewed the post trip report and determined that
the licensee had adequately addressed the issues identified.
e.
Inadequate Configuration Control
During the inspection period, the inspectors became concerned by
the number and increased frequency of loss of configuration
control events by the licensee. The inspectors noted these
problems through direct observation and review of the licensee's
PIP data base. The licensee's management was also concerned by
these events and initiated a formal root cause investigation to
consider the specifics of each incident and assess the adverse
trend. As of the end of the inspection period, the licensee's
investigation was still in progress. The specifics for the more
significant events are as follows:
-
On June 25, 1995, the feeder breaker for Unit 2 Low Pressure
Injection Valve, 2LP-2, was inadvertently opened. This
motor operated valve is normally closed at power and is
opened during shutdown (<450 psi) to establish decay heat
removal.
The Unit 2 Reactor Operator quickly discovered the
loss of power to 2LP-2 by noting that its control board
indication was not illuminated following a control room
board walkdown. The operator first changed the indicator
bulb and determined the bulb was not the problem. Upon
further investigation, the Unit 2 operators determined that
VOTES testing of 3LP-2 was ongoing.
The licensee's investigation revealed that a technician
associated with the 3LP-2 valve testing had inadvertently
opened the breaker for 2LP-2. Upon realizing his mistake,
the technician reclosed the breaker for 2LP-2 without
notifying operations. The technician's inadvertent breaker
Enclosure 2
4
manipulation caused 2LP-2 to be without power for 42
minutes. The licensee generated PIP-6-095-0781 to determine
the root cause and necessary corrective actions.
In addition to the original configuration control error, the
inspectors were concerned that the technician reclosed the
breaker without notifying operations. In response to this
concern, licensee management stated that it was their
expectation that any employee, upon discovering a
configuration control error, would inform operations and not
manipulate plant equipment. The loss of configuration
control for 2LP-2 is identified as Example 1 of Violation
50-269,270,287/95-18-01, Inadequate Configuration Control.
On June 20, 1995, the licensee discovered two LPSW valves
mispositioned. These valves (3LPSW-337 and 3LPSW-342) were
found in the open position despite attached red safety tags
which indicated the required position for the valves as
closed. This is identified as Example 2 of Violation
50-269,270,287/95-18-01.
On June 21, 1995, during a refueling outage, the licensee
discovered that Unit 3 feedwater valves 3FDW-141, 142, 143,
and 144 were removed from the system with the red safety
tags attached. This constituted a breach of the tagging
boundary and is identified as Example 3 of Violation 50
269,270,287/95-18-01.
On July 16, 1995, during the startup from a refueling
outage, the 3B2 Reactor Coolant Pump lower bearing oil
cooler temperature came into alarm. The licensee's
subsequent investigation determined the LPSW inlet and
outlet valves (3LPSW-106 and 3LPSW-236) to the oil cooler
were throttled. These valves were required to be in the
full open position. The mispositioning of 3LPSW-106 & 236
is identified as Example 4 of Violation 50-269,270,287/95
18-01.
On August 1, 1995, the licensee's maintenance organization
found a Red Tag attached to the wrong component. The Red
Tag (OPS-95-2209-4) was hung on "Feeder Bkr for MCC XOD3-1"
and should have been on "XOD3 Alt Incoming FDR Bkr."
The
failure to properly tag and open the correct breaker is
identified as Example 5 of Violation 50-269,270,287/
95-18-01.
On August 30, 1995, the inspectors observed numerous
discrepancies between the position of Keowee sliding links
and their associated configuration control tags (see
paragraph 3.a.(3)). The failure to maintain configuration
Enclosure 2
5
control for Keowee sliding link R95 is identified as Example
6 of Violation 50-269,270,287/95-18-01.
The inspectors concluded that the safety significance of each
example, when taken individually, was minor. However, the large
number and increased frequency of configuration control problems
were indicative of a programmatic weakness. The inspectors noted
that licensee management was also concerned by the recent problems
with configuration control and had devoted resources to determine
root cause(s).
f.
Loss of 3D2 Heater Drain Pump
The inspectors observed operator actions in the Unit 3 control
room on August 29, 1995, when the suction valve to the 3D2 Heater
Drain Pump closed due to problems with the 302 heater level
control system. This caused a trip of the 3D2 Heater Drain Pump
and initiated a transient in the feedwater system which could have
resulted in a reactor trip. However, due to prompt corrective
actions taken by the control room operators, the plant avoided a
reactor trip. This transient occurred during a lineup change to
the feedwater system. The inspector noted that the operators
conducted a thorough briefing prior to the lineup change during
which they discussed possible plant responses. The inspector
concluded that the pre-evolution briefing was a key element in the
operators effective response, and that the operator response to
this plant challenge was prompt and effective.
Within the areas reviewed, one violation with six examples regarding
inadequate configuration control was identified. The inspectors
concluded that the large number of examples of inadequate configuration
control represented a programmatic weakness, paragraph 2.e. Operators
demonstrated alert watchstanding by quickly identifying the loss of
power to valve 2LP-2, paragraph 2.e. Prompt corrective actions taken by
the control room operators following a heater drain pump trip avoided a
reactor trip, paragraph 2.f.
3.
Maintenance and Surveillance Testing (62703 and 61726)
a.
Maintenance activities were observed and/or reviewed during the
reporting period to verify that work was performed by qualified
personnel and that approved procedures adequately described work
that was not within the skill of the craft. Activities,
procedures and WOs were examined to verify that proper
authorization and clearance to begin work were given, cleanliness
was maintained, exposure was controlled, equipment was properly
returned to service, and LCOs were met.
Enclosure 2
6
Maintenance activities observed or reviewed in whole or in part
are as follows:
(1) Unit 2, ATWS Mitigation AMSAC/DSS Logic Test, WO 95056264
On August 10, 1995, the inspector observed activities in
progress during the performance of IP/O/B/0276, ATWS
Mitigation AMSAC/DSS Logic Test. The activity was performed
on Unit 2 which provides a means for testing the logic of
the AMSAC/DSS. The exercise, which was required to be
performed bi-annually with the reactor operating at power,
was performed to acceptable standards.
(2) Purification Of Emergency FDWPT Oil, OP/2/A/1106/24
The inspector reviewed activities in progress to purify the
lubrication oil for the Unit 2 Turbine Driven Emergency
Feedwater Pump on August 3, 1995. The effort, which is
required to be performed on a quarterly basis, was in
accordance with procedure OP/2/A/1106/24, Purification Of
Emergency FDWPT Oil, and was performed to acceptable
standards.
(3) Modification of Keowee Units 1 & 2 Overspeed Protective
Circuitry, TN/5/A/2966/BL1/02
On October 12, 1992, the licensee discovered a single
failure vulnerability for the Keowee units due to the "zone
overlap" of certain differential current protective relays
(LER 269/92-16). On January 11, 1993, the on-going "Keowee
Single Failure Analysis" identified the technical
inoperability of the KHUs while generating to the grid
during certain power/lake level combinations, due to turbine
overspeed (LER 269/93-01). These vulnerabilities resulted
in the inability to simultaneously generate both KHUs to the
grid. Therefore, modification NSM-52966 was initiated to
eliminate the vulnerabilities. This modification required
NRC approval, which was granted by letter dated August 15,
1995. In a letter dated February 27, 1995, the licensee
committed to complete the modification within thirty days of
NRC approval.
Oconee's NSRB recently made an issue of Oconee's failure to
meet commitments to the NRC in a timely manner. Based on
the NSRB emphasis on meeting commitments, the licensee felt
it important to complete the modification within 30 days of
August 15, 1995. While the issue of Oconee not meeting
commitments was valid, this specific 30 day commitment was
arbitrary and extending the work beyond 30 days would not
have adversely affected safety.
Enclosure 2
7
The procedure for implementing the modification of the
Keowee units overspeed protective circuitry is
TN/5/A/2966/BL1/02. It took approximately 10 months to
develop and is very extensive (379 pages).
This procedure
was completed on August 10, 1995, and was approved on August
20, 1995. The procedure was given to Work Control
Scheduling on August 21, 1995, with the expectation that
work would begin that weekend (August 25).
The schedulers
subsequently came up with a schedule of 69 hours7.986111e-4 days <br />0.0192 hours <br />1.140873e-4 weeks <br />2.62545e-5 months <br /> to complete
the overhead path LCO portion of the work. The associated
TS LCO for the overhead path work (TS 3.7.2) allowed the
overhead path to be out of service for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. The fact
that there was only three hours scheduled margin from
exceeding the LCO was apparently never communicated to
Safety Assurance or to the Oconee PORC.
The overhead path LCO was entered at 10:01 p.m., on August
28, 1995. Work was proceeding according to schedule when on
August 30, 1995, the resident inspectors identified problems
with work practices associated with the modification.
Specifically, there were six discrepancies noted between the
position of sliding links and the configuration control tags
(blue tags) associated with these links, and there were
numerous "uncontrolled" drawings at the work site intermixed
with "controlled" drawings. The resident staff informed
Oconee management of these deficiencies. After confirming
the findings, the licensee subsequently stopped work at 1:30
p.m., on August 30, 1995. The licensee implemented various
short-term corrective actions to verify all links affected
by the modification were in the correct position and tagged
as required, and removed all uncontrolled drawings from the
immediate work area. A PORC meeting was convened that
afternoon to discuss whether or not to fully complete the
work activity or to back out of the procedure in order to
restore overhead path operability prior to the LCO expiring.
It was at this PORC meeting that the majority of licensee
management first understood that the work stoppage placed
them in jeopardy of exceeding the LCO. It also became
apparent that in order to back out of the procedure, a major
change to the procedure would have to be written overnight.
Although a rough contingency plan had been considered prior
to beginning the work (i.e., they knew the step in the
procedure from which they could back out), a specific back
out procedure was not developed ahead of time. The PORC
decided that despite the uncertainties associated with
backing out of the procedure, it was prudent to pursue the
back out option. It was also at this PORC meeting that the
Compliance Department was directed to begin preparing a NOED
package in case there were problems with backing out of the
modification or with operability testing.
Enclosure 2
8
Work was resumed at 11:30 p.m., on August 30, 1995 (10 hour1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br />
delay).
Problems were experienced executing the back out
from the modification such that the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> LCO expired
(10:01 p.m.) and TS 3.7.3 was entered. TS 3.7.3 required
the shutdown of all three Oconee units within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> if
the overhead path is not returned to service. The licensee
requested a NOED from TS 3.7.3 in order to extend the time
to shut down the units from 12 to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> so that the units
could be shut down sequentially rather than in parallel.
The NRC gave approval to extend the time to shut down the
units from 12 to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The back out procedure and
operability testing were successfully completed in the early
morning hours of September 1, 1995. TS 3.7.3 was exited at
2:36 a.m., on September 1, 1995. Prior to exiting TS 3.7.3,
Unit 3 had reduced power to 76 percent (Units 1 & 2 remained
at 100 percent).
The inspectors were concerned with various aspects of the
modification implementation including scheduling, work
control, configuration control and management oversight.
The inspectors concluded that the licensee's commitment to
complete the modification within 30 days was made without
fully considering the scope of the work involved. The
inspectors concluded that the 30 day commitment resulted in
inadequate time for Work Control to plan and schedule a very
complex and comprehensive work activity. The inspectors
further concluded that appropriate contingency plans for
backing out of the work were not developed in sufficient
detail prior to beginning the work. This contributed to
exceeding the LCO in that the back out procedure did not
anticipate several equipment responses that required
significant LCO time to resolve.
Additionally, the inspectors concluded that management
oversight was minimal until the inspectors identified work
process errors. There was only one supervisor assigned to
oversee the modification implementation even though the work
was being accomplished on a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> basis by two teams (day
shift and night shift). Given the importance of the work
activity and the pressures of schedule, greater management
oversight would have been appropriate. Additionally, the
inspectors considered having "uncontrolled" drawings
intermixed with controlled drawings at the work site a poor
work practice.
After the inspector pointed out the examples of
discrepancies between the blue tags and sliding link
positions, licensee personnel determined that all but one
were the result of the technicians neglecting to
remove/update the tag after closing a link per the
Enclosure 2
9
controlling procedure. However, for one of the examples
(sliding link R95), the licensee personnel erroneously
concluded that the closed link (which conflicted with the
blue tag) should have been opened per the controlling
procedure and therefore opened the link. In reality, the
procedure (step 8.45) required the link to be closed.
Therefore, in an effort to correct a perceived misposition
problem, the licensee personnel created an actual
mispositioned link. As previously addressed in paragraph
2.e. of this report, the failure to maintain configuration
control for Keowee sliding link R95 is identified as Example
6 of Violation 50-269,270,287/95-18-01.
The inspectors noted that there was not a consistent
understanding among station personnel on the purpose and
programmatic aspects of blue tags. The inspectors noted
that the only written description of blue tags and their
usage was contained in Maintenance Directive 4.4.13, ONS I&E
Configuration Control Work Practices. The inspectors
concluded that this directive did not contain sufficient
information to ensure configuration control would be
maintained. For example, the directive did not address when
to hang or remove the tag, or how to handle multiple
components on the same tag.
In response to the concerns raised over exceeding the 72
hour LCO and the request for a NOED, the licensee agreed to
postpone any further work on the modification until a root
cause assessment was completed. The licensee chartered an
incident investigation team composed of non-Oconee Duke
Power personnel to investigate the event. As of the end of
the inspection period the licensee's investigation was not
complete.
(4) Bi-Annual Inspection of Keowee Unit 2 Turbine, WO 95026904
On August 7, 1995, the inspector accompanied licensee
personnel on an inspection of the Keowee Unit 2 spiral case
and turbine. The inspector noted that the area was free of
debris and that there was no apparent damage to any of the
turbine blades and wicket gates. All activities observed
were satisfactory.
(5) Keowee Unit 2 Turbine Guide Bearing Temperature Instrument
Calibration, WO 95039370
On August 23, 1995, the inspector observed portions of this
calibration activity in progress. The inspector verified
that the work was being accomplished in accordance with an
approved procedure, that all test equipment was properly
Enclosure 2
10
calibrated, and that the Keowee operator was aware of the
work in progress. All activities observed were
satisfactory.
(6) Keowee Unit 2 Ground Hunt, WO 95067298
On August 28, 1995, the annunciator for Keowee Unit 2 DC
positive ground came into alarm. The inspector observed the
subsequent ground hunting efforts and concluded that the
ground hunt received adequate support from Oconee
Engineering and I&E personnel.
The inspector noted that
even though Keowee Unit 2 was technically operable, an
operability run was performed to verify the ground had no
effect on unit operation. The inspector considered this a
conservative decision. The operability run was successful
and upon securing the unit, the annunciator cleared. The
alarm later recurred and the licensee was able to determine
the cause to be a pinched wire in the field breaker.
Replacement of this wire successfully eliminated the ground.
The inspector concluded that the licensee's prompt and
extensive ground hunting effort constituted a strength in
corrective maintenance.
(7) Route Chiller Discharge To CCW, WO 59011388
The inspector observed activities in progress during the
implementation of Nuclear Station Modification NSM 52990 on
August 3, 1995. The effort involved a piping and valving
modification to reroute the cooling water discharge (Low
Pressure Service Water) from the Auxiliary Building Air
Handlers to the Units 1 and 2 Condenser Circulating Water
(CCW) discharge piping. The air handler discharge was
previously routed to the Chemical Treatment Pond. The work
document referenced MP/0/B/1810/015, Welding-Piping And
Valve Removal and Replacement Of Class "G", "H", and QA
Condition 3, which was being utilized for the activity. The
inspector determined the work was in accordance with
approved procedures.
b.
The inspectors observed surveillance activities to ensure they
were conducted with approved procedures and in accordance with
site directives. The inspectors reviewed surveillance
performance, as well as system alignments and restorations. The
inspectors assessed the licensee's disposition of any
discrepancies which were identified during the surveillance.
Enclosure 2
11
Surveillance activities observed or reviewed in whole or in part
are as follows:
(1) Reactor Building Spray Pump Test, PT/2/A/0204/07
The inspectors observed performance testing of the Unit 2
Reactor Building Spray Pumps. The quarterly test was
conducted on August 22, 1995, to demonstrate operability of
the pumps. The inspectors verified that the appropriate LCO
status was entered as required during the time that the
testing was in progress. The results of the test were
within acceptable tolerances and the test was performed to
acceptable standards.
(2) Keowee Unit 2 Load Rejection Test, TT/O/A/620/08
The inspectors observed testing of Keowee Unit 2 performed
on September 3, 1995. The test was performed following
modification work to verify that Unit 2 would disconnect
when supplying power to the grid and realign to a "speed no
load" condition in the event of an emergency start signal
from ONS. The testing was required to verify operability of
the unit as an emergency power supply to ONS when generating
power to the grid. The testing was successful and the unit
performed as expected.
(3) Keowee Unit 2 Operability Verification, OP/O/A/1106/19
On September 1, 1995, the inspector observed the operability
test of Keowee Unit 2 to the overhead path. The inspector
observed that the test was conducted in accordance with
procedures and achieved acceptable results.
Within the areas reviewed, concerns were identified regarding the
implementation of a Keowee modification. Concerns included inadequate
planning, lack of management oversight, and lack of configuration
control, paragraph 3.a.(3). The prompt and comprehensive efforts to
locate and eliminate a DC ground at Keowee were identified as a
strength, paragraph 3.a.(6).
4.
Onsite Engineering (37551 and 92903)
During the inspection period, the inspectors assessed the effectiveness
of the onsite design and engineering processes by reviewing engineering
evaluations, operability determinations, modification packages and other
areas involving the Engineering Department.
On June 21, 1995, technicians observed that the LPI header A and B
throttle valves had different stroke lengths. Further investigation
revealed that a vendor-supplied drawing had provided an erroneous flow
Enclosure 2
12
coefficient for the two valves. This error resulted in a non
conservative value for the LPI pump runout calculation for the Loss of
Coolant Accident/Loss of Offsite Power event. On July 24, 1995, the
licensee declared that all three units' LPI systems had been inoperable
in the past during a period when the valves had been powered by non
safety power and no credit could be taken for valve operator
performance. During that time, operating personnel may not have been
able to throttle LPI flow during an event and prevent pump runout. The
power to the Unit 2 valves was upgraded to safety-related in 1993, and
Units 1 and 3 in 1994. After upgraded power was provided, assurance for
valve operator performance and thus valve throttling was provided to
control flows and prevent pump runout. Therefore, the operability
concern was no longer valid.
This issue will be addressed further during review of associated LER 269/95-06, Low Pressure Injection System Technically Inoperable Due To
Design Error, issued August 23, 1995.
Within the areas reviewed, licensee activities were satisfactory.
5.
Plant Support (71750 and 40500)
The inspectors assessed selected activities of licensee programs to
ensure conformance with facility policies and regulatory requirements.
During the inspection period, the following areas were reviewed:
a.
Radiological Controls and Health Physics
The inspectors reviewed the licensee's efforts at dose reduction
during the Unit 3 refueling outage, which was completed July 23,
1995. The licensee expected high total dose accumulation for the
outage due to the unusually high Reactor Coolant System (RCS)
activity levels. RCS activity in Unit 3 had been high for
virtually the entire cycle due to failed fuel pins.
The licensee implemented several measures designed to reduce the
outage dose in accordance with ALARA. These included increased
RCS crud burst and cleanup times during shutdown, as well as
special prophylactic measures at critical access points.
As a result of these efforts, the total accumulated personnel dose
was 164 REM, a record low for a refueling outage at Oconee. The
licensee's efforts to reduce the RCS activity levels was cited as
a strength in inspection report 50-26,270,287/95-11. The results
achieved over the course of the refueling outage confirm the
effectiveness of those efforts.
Enclosure 2
13
b.
Self-Assessment
During the inspection period, the inspectors attended routine and
special PORC meetings. The PORC members were well prepared for
the meetings which addressed a wide range of technical and
programmatic issues. The meetings were well organized, candid
dialogue was encouraged, and emphasis was placed on safety.
Within the areas reviewed, licensee activities were satisfactory.
6.
Exit Interview
The inspection scope and findings were summarized on September 13, 1995,
with those persons indicated in paragraph 1 above. The inspectors
described the areas inspected and discussed in detail the inspection
findings addressed in the Summary and listed below. No dissenting
comments were received from the licensee. The licensee did not identify
as proprietary any of the material provided to or reviewed by the
inspectors during this inspection.
Item Number
Status
Description/Reference Paragraph
Violation 269,270,287/
Open
Inadequate Configuration Control,
95-18-01
Six Examples (paragraph 2.e)
7.
As Low As Reasonably Achievable
Accident Mitigation System Actuation Circuitry
Anticipated Transients Without Scram
CFR
Code of Federal Regulations
Condenser Circulating Water
Control Rod Drive
Direct Current
Diverse Scram System
FDWPT
Feedwater Pump Turbine
I&E
Instrument & Electrical
KHU
Keowee Hydro Unit
LER
Licensee Event Report
LCO
Limited Condition for Operability
Loss of Coolant Accident
Low Pressure Injection
Low Pressure Service Water
Notice Of Enforcement Discretion
Nuclear Safety Review Board
NSM
Nuclear Station Modification
Oconee Nuclear Station
Plant Operating Review Committee
Problem Investigation Process
Enclosure 2
14
Roentgen Equivalent Man
TS
Technical Specifications
Work Order
Enclosure 2