ML16154A807
| ML16154A807 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 07/12/1995 |
| From: | Crlenjak R, Harmon P NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML16154A806 | List: |
| References | |
| 50-269-95-11, 50-270-95-11, 50-287-95-11, NUDOCS 9507200034 | |
| Download: ML16154A807 (17) | |
See also: IR 05000269/1995011
Text
SREGj
UNITED STATES
NUCLEAR REGULATORY COMMISSION
REGION II
101 MARIETTA STREET, N.W., SUITE 2900
ATLANTA, GEORGIA 30323-0199
Report Nos.: 50-269/95-11, 50-270/95-11 and 50-287/95-11
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 Conducte
ay 28 - J e 24, 1995
Inspectors * A ,Z
q
E. 'HarmsSenior R ident Inspector
ate Signed
W. K. Poertner, Resident Inspector
L. A. Keller, Resident Inspector
P. G.
phrey, Re ide
t Inspector
Approved by:
WFV. Crle r
f
Date Signed
Reactor Projects Branc 3
SUMMARY
Scope:
This routine, resident inspection was conducted in the areas of
plant operations, maintenance and surveillance testing, onsite
engineering, and plant support. It included an inspection of open
items and licensee event reports.
Results:
One violation, one inspector followup item, and one programmatic
strength were identified. In addition, a weakness in designating
the proper Quality Assurance (QA) classification was identified in
the licensee's work control system.
In the operations area, Unit 3 mid-loop activities were conducted
safely. The licensee's program, which included redundant
instrumentation, containment controls and contingency plans, was
well implemented, paragraph 2.c.
In the area of maintenance, a weakness in designating the proper
QA classification was identified in the licensee's work control
system, paragraph 3.a.(5). An inspector followup item was
identified regarding the QA level assigned to Condenser
ENCLOSURE 2
9507200034 950712
PDR ADOCK 05000269
2
Circulating Water (CCW) pump breaker maintenance activities,
paragraph 3.a.(7).
In the area of engineering, a violation was identified involving
the failure to initiate the Problem Investigation Process (PIP) in
a timely manner for a problem with containment isolation valves,
paragraph 4.a.
In the area of plant support, licensee management's support of
efforts to reduce Unit 3 outage dose was considered a strength,
paragraph 5.c.
ENCLOSURE 2
REPORT DETAILS
1.
Persons Contacted
Licensee Employees
B. Peele, Station Manager
- E. Burchfield, Regulatory Compliance Manager
D. Coyle, Systems Engineering Manager
- J. Davis, Engineering Manager
T. Coutu, Operations Support Manager
- W. Foster, Safety Assurance Manager
- J. Hampton, Vice President, Oconee Site
- D. Hubbard, Maintenance Superintendent
- B. Jones, Training Manager
C. Little, Electrical Systems/Equipment Manager
- J. Smith, Regulatory Compliance
- G. Rothenberger, Operations Superintendent
R. Sweigart, Work Control Superintendent
Other licensee employees contacted included technicians, operators,
mechanics, security force members, and staff engineers.
- Attended exit interview.
2.
Plant Operations (71707)
a.
General
The inspectors reviewed plant operations throughout the reporting
period to verify conformance with regulatory requirements,
Technical Specifications (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, instrument & electrical
(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,
ENCLOSURE 2
2
housekeeping, security, equipment status, and radiation control
practices were observed.
b.
Plant Status
Unit 1 operated at full power throughout the reporting period.
Unit 2 operated at full power throughout the reporting period.
Unit 3 operated at full power until June 6, 1995, when the unit
began a scheduled 35-day end of cycle refueling outage.
c.
Mid-Loop/Reduced Inventory Activities
During the Unit 3 End Of Cycle 15 Refueling Outage (U3EOC15), the
licensee reduced Reactor Coolant System (RCS) inventory and
reached the mid-loop operations level on June 12, 1995. This was
done for the purpose of installing nozzle dams in the steam
generators. The inspectors reviewed the licensee's program prior
to the reduction of RCS inventory and verified that the
requirements were met while operating at the reduced inventory
levels as specified in Operations Procedure OP/3/A/1103/11,
Draining And Nitrogen Purging Of RC System, Enclosure 3.6,
Requirements For Reducing RXV Level To < 50" On LT-5. This
procedure stipulated the sequence and steps required for reduction
of RCS inventory and mid-loop operation. It further specified the
precautions and limitations to be adhered to while in mid-loop.
Step 1 of Enclosure 3.6 specifically addressed the ability to
establish containment closure. The licensee implemented a
Shutdown Protection Plan for the outage which required containment
closure to be maintained except as necessary to bring materials
and tools in and out of the reactor building. The Plan further
required that penetrations be closed, except for those with
temporary cables installed, as necessary for outage activities
such as steam generator tube testing and maintenance.
The inspector verified that the requirement for two independent
trains of RCS level monitoring was met while at reduced inventory.
This was accomplished by the use of two permanently installed
instruments (LT-5A and LT-5B) and two temporary ultrasonic
instruments. Level indications were displayed in the control room
on the LT-5A and LT-5B indicators, the Inadequate Core Cooling
Monitor, and on the Operations Aid Computer.
The inspector verified that two trains of core exit thermocouples
were available and utilized while at reduced inventory, as well as
the two sources of inventory makeup and cooling were available for
operation. The inspector reviewed the licensee's contingency
ENCLOURE 2
3
plans to repower vital busses from available alternate electrical
power supplies in the event of a loss of the primary source.
The licensee was at reduced inventory for approximately 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br />.
During the time that Unit 3 was in a reduced inventory status, the
licensee implemented and maintained the requirements specified by
procedure, and the operation at reduced inventory was accomplished
without incident. The inspector concluded that this reduced
inventory evolution was well coordinated and controlled.
Within the areas reviewed, licensee activities were satisfactory.
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 work orders (WO) were examined to verify that
proper authorization and clearance to begin work was given,
cleanliness was maintained, exposure was controlled, equipment was
properly returned to service, and limiting conditions for
operation were met.
Maintenance activities observed or reviewed in whole or in part
are as follows:
(1) Replace RCS High Point Vents, WO 95005775
The inspector witnessed part of a modification (NSM-32927)
that added a dedicated shutdown vent line to the Unit 3
quench tank from the existing Unit 3 High Point Vent (HPV)
system. The activity observed was the replacement of
existing HPV valves 3RC-19 and 3RC-38 with new class "A"
Anderson Greenwood 1-inch manual globe valves. In addition
to observing portions of the work in the field, the
inspector reviewed the licensee's 10CFR5O.59 evaluation for
the modification, reviewed the work order, verified that the
manufacturer's certificate of conformance for these valves
matched the specifications called for in the licensee's
purchase order, and verified that the control room drawings
reflected the new piping configuration. All activities
observed, and all documentation reviewed, were satisfactory.
(2) Perform Bench Test on 3BS-2, WO 94089245
The inspector observed the post maintenance test conducted
on Unit 3 building spray valve 3BS-2. The test was
conducted in accordance with procedure IP/O/A/3001/11F,
Limitorque Actuator Testing Using KALSI Engineering Test
ENCLOSURE 2
4
Bench. This test measured the developed torque by the valve
operator at various voltages. For the test conducted at 75%
voltage, the developed torque was 718 ft-lbs in the open
direction and 728 ft-lbs in the close direction. Both
measured values were below the calculated value of 754 ft
lbs. The licensee initiated a Problem Investigation Process
(PIP) for this discrepancy. This PIP concluded that the
developed torque was adequate for this motor operated valve
to meet all design basis requirements. As of the end of the
inspection period the licensee was still trying to resolve
the difference between the predicted and actual torque
values. The inspector concluded that the test was conducted
in accordance with the procedure and that actions taken to
resolve test deficiencies were appropriate.
(3) Replace 3HP-410 With Item No. DMV-1023, WO 94093641
The inspector observed replacement of Unit 3 High Pressure
Injection valve 3HP-410 on June 16, 1995. The effort
involved cutting out the existing valve and installing the
new one. The inspector noted that the work was performed in
accordance with Minor Modification OE-7089. The inspector
reviewed the hot work permit for the welding process that
was included as part of the work package. All work observed
was determined to meet acceptable standards.
(4) Repair 3BS-1 Seat Leak, WO 95019948
The inspector observed repair of Unit 3 building spray valve
3BS-1 on June 16, 1995. The valve bonnet was being re
installed on the valve body. The effort was in accordance
with MP/0/A/1200/002A, Valve - Globe - Pressure Seal and
Bolting Bonnet Disassembly, Repair, and Reassembly.
Additional procedures were provided with the work package
which included MP/O/A/1200/001D, Valves - NRC - 89-10
Replacing and Adjusting Packing, and MP/0/A/1210/007,
Operator - Limitorque SMB/SB Series - Removal and
Replacement. The work effort reviewed was in accordance
with plant procedures and documentation was updated to the
current work status.
(5) Inspect and Clean The A HPSW Pump Strainer, WO 95029083
The inspector reviewed activities performed to inspect and
clean the strainer at the suction of the High Pressure
Service Water (HPSW) pump. Maintenance procedure,
MP/0/A/1800/003, Flanges - Torquing, was attached as part of
the work package which listed the torquing values and
tightening sequence for the replacement of the strainer
flange. However, the procedure torque values were not
ENCLOSURE 2
S
5
utilized since the gasket was rubber. The values were
changed by the system engineer from 581 psi to 100 psi.
The inspector noted that the work package was designated as
non-QA. The inspector questioned the appropriateness of
work on the HPSW system to non-QA standards. As a result,
the licensee evaluated the classification and determined
that it should have been classified as QA level III.
Since
the standards were essentially the same for QA level III
classification work and non-safety work, the inspector
concluded that there was no safety impact. The inspector
concluded that the failure to appropriately classify this
work constituted a weakness in the licensee's work control
system.
(6) Replacement of NI-2 and NI-4, WO 93052259
The inspector observed portions of the replacement of Unit 3
nuclear instrumentation NI-2 and NI-4. The inspector
concluded the work activity was in accordance with Nuclear
Station Modification NSM-32909, which provided the guidance
for the replacement of a source range (NI-2) and
intermediate range (NI-4) detector with Gamma-Metrics system
full scale operating range detectors. The inspector
concluded that the work activity was performed to acceptable
standards.
(7) Replace Broken Fuse Block in 3TC-4, WO 95032254
The inspector observed corrective maintenance activities
associated with the replacement of a broken fuse block in
4160 volt switchgear 3TC. During the maintenance activity
the original installed fuses did not fit the replacement
fuse block. The original fuses were type K fuses and the
replacement fuse block required type R fuses. The
replacement fuse block was supplied by the vendor as a
direct replacement for the existing fuse block. The
maintenance personnel reinstalled the old fuse block (with
original fuses) and initiated a PIP to determine the
appropriate replacement fuses and the means of documenting
appropriate replacement fuses on drawings.
The PIP also
identified that no documentation existed to control the
replacement of fuses for the safety-related switchgear. The
fuse replacement program is essentially a like-for-like
process. When a different type fuse is required, design
information specifying the original fuse is frequently
unavailable or inadequate. This substantially complicates
the process for specifying a new fuse.
ENCLOSURE 2
6
While reviewing the work order the inspector questioned the
Quality Assurance (QA) level identified on the work order.
The work order stated that the work activity was non-QA.
The broken fuse block was associated with the control power
for the 3A Condenser Circulating Water (CCW) pump and the
fuse block is part of the feeder breaker for this pump.
This breaker is required to open during a load shed
condition. Subsequent discussions with the licensee
determined that the replacement parts were QA parts.
The licensee had originally considered the breaker
non-QA, but had committed to the NRC to maintain and test
the breaker to QA requirements as a result of a violation
(50-269,270,287/93-02-01) issued during the Electrical
Distribution System Functional Inspection (NRC Inspection
Report 50-269,270,287/93-02). The licensee stated that the
non-QA specification on the work order was based on the
initial QA classification, but that the work activity was
identified as being conducted to QA requirements based on
the NRC commitment. Pending completion of the licensee PIP
evaluation and review of control power QA requirements by
the inspectors, this item is identified as Inspector
Followup Item 50-269,270,287/95-11-01:
Pump Breaker Activities.
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.
Surveillance activities observed or reviewed in whole or in part
are as follows:
(1) High Pressure Injection Pump Test, PT/2/A/0202/11
The inspector observed performance testing of the Unit 2
high pressure injection pumps and associated check valves on
June 14, 1995. The purpose of the test was to demonstrate
operability of the equipment required to meet Technical
Specification requirements. The inspector concluded that
testing activities were performed according to the procedure
and acceptance criteria were met.
(2) Motor Driven Emergency Feedwater Pump Test, PT/1/A/0600/13
The inspector observed surveillance activities associated
with the 1A Motor Driven Emergency Feedwater pump. The
performance test implements the requirements of ASME Section
XI. The inspector concluded that the testing activities
ENCLOSURE 2
7
were performed in accordance with the procedure and the
procedure acceptance criteria were met.
(3) Unit 3 Mainfeeder Bus 1 Lockout Test, TT/3/A/0610/013
The inspector observed a test of the Unit 3 Mainfeeder Bus
- 1 (MFB1) lockout relays. These relays were energized by
manually operating initiating relays (current and
differential). All activities observed were satisfactory.
The inspector concluded that this test verified that the
Unit 3 MFB1 lockout relays operated properly.
Within the areas reviewed, the failure to provide the appropriate QA
category to a HPSW work activity was identified as a weakness in the
licensee's work control system, paragraph 3.a.(5). An Inspector
Followup Item was identified regarding the QA level assigned to CCW pump
breaker maintenance activities, paragraph 3.a.(7).
4.
Onsite Engineering (37551)
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.
a.
Failure To Initiate Problem Investigation Process (PIP) In A
Timely Manner
On May 23, 1995, Revision 2 of Oconee Calculation OSC-2061, Oconee
Unit 3 Voltage and Load Study, was signed as an approved
engineering document. Section 4.0 of this calculation indicated
that with the 230 KV switchyard supplying Unit 3 via Startup
Transformer CT3, coincident with a Loss Of Coolant Accident
(LOCA), the computed minimum voltages at the motor terminals for
motor-operated valves (MOVs) 3HP-3, 3HP-4, and 3HP-20 were below
the computed minimum operating voltages previously analyzed.
These three valves are part of the High Pressure Injection system
which receive an Engineered Safeguards (ES) signal to close
following an accident requiring containment isolation.
The licensee's vehicle for resolving operability questions or
conditions adverse to quality is the PIP. Nuclear System
Directive 208, Problem Investigation Process (PIP), is the
controlling document for the PIP. NSD 208, Appendix E, indicates
that the discovery of a condition which calls into question the
current or past operability of a system or component, required to
be operable by TS, requires the initiation of a PIP. Therefore,
the fact that the operability of these containment isolation
valves was in question should have resulted in the immediate
initiation of a PIP. In fact, Section 4.0, "Conclusions And
ENCLOSURE 2
8
Recommendations," of OSC-2061 states in part that "A PIP item must
be generated on the new minimum voltages for the three above-named
MOVs..."
However, a PIP for this issue was not initiated until
June 6, 1995 (PIP 3-095-0663). The licensee subsequently
completed an analysis which showed that the three MOVs in question
had been operable at the new minimum starting voltage. However,
due to the lack of margin for 3HP-20 (less than 10 percent), the
licensee replaced 315 feet of motor feeder cable with cable of
less resistance (#6 AWG versus #10 AWG).
The inspectors first became aware of the issue on June 7, 1995,
upon reading PIP 3-095-0663. The inspectors recalled that the
subject calculation (OSC-2061) was part of a group of Emergency
Power Upgrade Project calculations that were completed several
weeks earlier, and therefore questioned the timeliness of this
PIP. In response to the inspector's inquiry, licensee management
stated that they were unaware that this issue was several weeks
old. The inspectors noted that the applicable Technical
Specification action statement (TS 3.6) time frame for containment
isolation valves was 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The inspectors concluded that the
15 days taken by the licensee to initiate the PIP for this problem
did not meet the requirements of NSD 208, and was not commensurate
with the safety significance of containment isolation valves. The
licensee agreed that their PIP initiation for this problem was not
timely, and indicated that it was their expectation that a problem
that brought into question the operability of a safety-related
system or component would result in the immediate initiation of a
PIP. As of the end of the inspection period, the licensee was
still investigating the failure to initiate a PIP in a timely
manner. This matter is identified as Violation 287/95-11-02:
Failure to Initiate a PIP in a Timely Manner.
b.
Emergency Power Upgrade Project Items
Keowee Hydro Station was designed, constructed, and maintained to
hydroelectric standards. The hydro station was not originally
under the Nuclear Generation Department management, and
documentation and programmatic controls have not been consistent
with nuclear industry standards. Over the years several events
and internal/external assessments resulted in a growing list of
commitment items. These included the May 15, 1992, Self-Initiated
Technical Audit (SITA), October 1992 loss of offsite power event,
Electrical Distribution System Functional Inspection (EDSFI), and
the Design Basis Document (DBD) review program. In order to
manage the list of commitment items, the licensee initiated the
Oconee Emergency Power Upgrade Project.
This upgrade project provides for the engineering analyses,
procedure upgrades, maintenance program development, and
configuration documentation/upgrade for the Keowee Hydro Station
ENCLOSURE 2
III9
and the Emergency Power Path of Oconee Nuclear Station. The
licensee stated that this project will fully incorporate Keowee
into the Oconee nuclear maintenance program and satisfy all open
commitment items. The project contains approximately 160
individual items.
During this inspection period the inspectors reviewed the
following project items:
(1) Investigate Need For MG-6 Relay Covers (Item #32)
This item was the result of two MG-6 relay failures during
September 1992 that were attributed to dirty contacts. The
licensee subsequently determined that relay covers would not
prevent the type of contact fouling which occurred in these
two instances; therefore, they decided not to install relay
covers. The inspector noted that there have been over 500
Keowee Hydro Unit starts since September 1992 without
further MG-6 relay problems. The inspector concluded that
the licensee's decision not to install relay covers was
acceptable.
(2) Inspect Westinghouse Electromechanical Relays for Stress
Cracks (Item #43)
A Westinghouse vendor notice (VIL-W 89-25) documented that
the moving contact holder in certain Westinghouse
electromechanical relays had developed stress cracks.
Westinghouse stated in their notice that the relays subject
to this stress cracking were probably manufactured during
the years 1981-1983. Keowee Hydro Station relaying systems
were installed during the period from 1970 through 1972.
Although no problems were anticipated, the licensee
inspected the contact holders for Westinghouse relays. No
problems were identified as a result of the licensee's
inspection. The inspector concluded that the licensee's
actions were adequate.
(3) Revise Loss of Power Abnormal Procedure, AP/1/A/1700/11,
(Item #31)
The 1992 electrical distribution SITA identified an
inconsistency within AP/1/A/1700/11 regarding the amount of
time required to establish RCS makeup and primary to
secondary heat transfer, in order to prevent core damage.
The licensee subsequently revised the procedure. The
inspector reviewed the latest revision of the procedure and
concluded that the changes effectively eliminated the SITA
concern.
ENCLOSURE 2
10
(4) Development of Alarm Indications for Loss of Control Power
to Keowee Air Circuit Breakers (Item #64)
In response to problems with loss of control power to Keowee
Air Circuit Breakers (ACBs) going undetected for a prolonged
period of time, the licensee developed Nuclear Station
Modification (NSM) ON-52944. This NSM will, when
implemented, provide Operations the ability to diagnose
control power failures on ACB-5,6,7 & 8 in a timely manner.
This modification will add an alarm relay (1 each) to the
close coil control circuit of ACB-5,6,7, & 8 to indicate
loss of 125 VDC control power. The inspector verified that
the new relays will be safety-related and will provide
isolation between the safety power supply and the non-safety
alarm outputs. The inspector reviewed the final scope
document for this NSM and concluded that it was adequate.
This NSM is scheduled for implementation during October
1995.
Within the areas reviewed, a violation was identified regarding the
failure to initiate the Problem Investigation Process in a timely manner
for a problem which called into question the operability of containment
isolation valves, paragraph 4.a.
5.
Plant Support (71750, 40500, and 64704)
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.
Fire Protection
The inspectors reviewed the Oconee Nuclear Station Fire
Protection/Prevention Program. The review included Site Directive
(SD) 3.2.7, Control Of Combustible Materials; SD 3.2.8, Fire
Brigade Organization And Training; SD 3.2.9, Reporting Of Fire
Protection Impairment; and SD 3.2.10, Hot Work Permit
Authorization Directive. Program operability requirements were
specified in Section 16.9, Auxiliary Systems - Fire Protection
Systems, of the Selected Licensee Commitment (SLC) Manual which
specified the surveillance requirements and compensatory measures
for impaired equipment and fire barriers.
The inspector routinely observed housekeeping throughout the plant
during the inspection period. The areas observed were kept clean
and the use of fire hazard materials appeared to be minimized.
The inspector noted that fire extinguishers and hose stations were
inspected by the licensee within the allowable inspection time
period. Hot work permits reviewed by the inspector were adequate.
The inspector witnessed a fire drill on May 16, 1995, that
ENCLOSURE 2
simulated a fire in the basement of the Unit 3 turbine building.
All documents reviewed, and activities observed were satisfactory.
The inspector reviewed a fire protection audit, SA-95-24(ON)(RA),
dated May 8, 1995 through June 8, 1995. The audit utilized the
services of a consultant fire protection engineer. The audit
identified several strengths and weaknesses. The inspector
verified that the audit concerns were documented in the licensee's
PIP for resolution. The inspector concluded that this audit was
adequate and represented good self-assessment in the area of fire
protection.
The inspector concluded that the licensee's fire protection
program was adequate, and that in general, the implementation of
the program was in accordance with the program requirements.
b.
Unit 3 Failed Fuel
During cycle 15, Unit 3 had high reactor coolant system.(RCS)
activity. Based on the cycle 15 radiochemistry the licensee
estimated that there were 3 to 4 failed fuel pins with likely
secondary hydride failures. During this inspection period Unit 3
began a scheduled refueling outage (3EOC15), in which the entire
core underwent an ultrasonic examination. The ultrasonic test
(UT) revealed that 22 fuel pins had failures. These 22 pins were
located in 16 different fuel assemblies. Of these 16 assemblies,
13 were first burn assemblies (19 fuel pins), 3 second burn
assemblies (2 fuel pins), and 1 third burn assembly (1 fuel pin).
The majority of the failed fuel pins (19 of 22) were replaced with
new uranium dioxide rods using standard fuel reconstitution
techniques. Two of the pins had such extensive damage that a
complete recaging of their associated fuel assemblies was
required. The failed pin in the third burn assembly was not
replaced since that assembly was not being returned to the core.
Based on the nature of the failures the licensee concluded that
they were not debris induced.
The inspectors witnessed portions of the UT and reconstitution
effort and concluded that the activities observed were
satisfactory. As of the end of the inspection period the licensee
was still evaluating why their estimate for the number of failed
pins was greatly underestimated and what was the cause of the
failed fuel.
c.
Unit 3 Outage Dose Reduction Efforts
Due to operating the previous cycle with failed fuel there were
high fission product and activation inventories throughout systems
which came into contact with Unit 3 reactor coolant. The high
amount of activity associated with Unit 3 provided the likelihood
ENCLOSURE 2
- II12
of high outage dose. In order to reduce outage dose the licensee
incorporated several shutdown chemistry practices designed to
maximize the cleanup of the RCS during cooldown. These shutdown
chemistry practices included the addition of temperature holds
during the cooldown process designed to maximize the chemical
reactions that take place during certain phases of the shutdown.
This was followed by hydrogen peroxide addition (crudburst) to
achieve acid oxidizing conditions which further dissolved
activation products from RCS piping. After hydrogen peroxide
addition, a 40 hour4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> purification was undertaken to remove these
activation products through the purification demineralizer system.
The acid oxidizing phase of the crudburst allowed the removal of
approximately 738 curies of cobalt from the RCS.
The cooldown temperature holds were incorporated into the Unit 3
outage schedule after a licensee review of elevated dose rate
events at Catawba and McGuire Nuclear Stations following
accelerated shutdowns. This review indicated that there was a
relationship between accelerated cooldowns and elevated shutdown
dose rates. Therefore, the licensee established: (1) a 6-hour
hold at hot shutdown; (2) a 6-hour hold at 350 degrees fahrenheit;
and (3) a 16-hour hold prior to the addition of hydrogen peroxide.
These holds prevented the formation of particulates which deposit
in the RCS and cause elevated dose rates. Approximately 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />
were added to the Unit 3 critical path activity due to these
chemistry holds and the prolonged purification evolution.
The inspectors observed that these chemistry holds resulted in
lower dose rates than that experienced during the previous outage
(3EOC14). This was significant considering the activity levels
going into this outage were much higher than the previous outage.
The inspectors concluded that the licensee's willingness to
substantially extend their outage critical path schedule in order
to reduce dose was an example of management commitment to their
ALARA program. Additionally, the inspectors concluded that the
licensee's incorporation of lessons learned from the Catawba and
McGuire outages to be an example of good self-assessment.
Within the areas reviewed, licensee activities were satisfactory. The
licensee's efforts to reduce Unit 3 outage dose was considered a
strength (paragraph 5.c).
ENCLOSURE 2
13
6.
Inspection of Open Items (92902, 92903 and 92904)
The following open items were reviewed using licensee reports,
inspection record review, and discussions with licensee personnel, as
appropriate:
a.
(Closed) Violation 287/93-31-03, Failure To Evaluate Materials For
Fire Loading
The inspectors had identified equipment and scaffolding in the
penetration rooms where flammable plastic had been used as wrap
for those items. The licensee was notified of the condition and
was responsive in the removal of the material. In addition, the
licensee reviewed the use of combustible materials in accordance
with Site Directive 3.2.7 with all groups of personnel involved
with the use of this material. The inspectors determined the
licensee's actions to be acceptable for correcting the issue and
preventing recurrence.
b.
(Closed) Violation 269,270,287/93-31-02, Inadequate 50.59
Evaluation
This violation identified that an inadequate 50.59 evaluation was
performed to implement a modification to the Keowee breaker
control logic to allow operation of both Keowee Hydro Units to the
electrical grid for power generation purposes. The 50.59
evaluation should have determined that a Technical Specification
(TS) change was required prior to implementation of the
modification. The corrective action associated with this
violation included revising Nuclear System Directive (NSD) 209,
10CFR 50.59 Evaluations, to clarify and emphasize the need to
consider new TS surveillances when performing safety evaluations.
The inspectors verified that NSD 209 had been revised.
c.
(Closed) Violation 269,270/93-23-01, Failure To Follow Procedures
To Maintain Configuration Control
This violation addressed the failure of Maintenance personnel to
properly control the configuration of lifted leads during
maintenance activities on a control power panelboard. When the
lifted leads were improperly reterminated, alternate power to the
panelboard was not available when the normal power supply was
tripped. This resulted in a reactor trip, which is described in
the closure evaluation of Licensee Event Report (LER) 269-93-08,
detailed in paragraph 7.b of this inspection report. The
inspector verified that the corrective actions for this violation
and the LER were implemented.
ENCLOSURE 2
14
7.
Review of Licensee Event Reports (92700)
The below listed Licensee Event Reports (LER) were reviewed to determine
if the information provided met NRC requirements. The determination
included: adequacy of description, compliance with Technical
Specification and regulatory requirements, corrective actions taken,
existence of potential generic problems, reporting requirements
satisfied, and the relative safety significance of each event. The
following LERs are closed:
a.
(Closed) LER 269/93-04, A Postulated Single Failure During a
LOCA/LOOP May Result In The Loss Of Post Accident Cooling Due to A
Design Deficiency
On April 5, 1993, the inspectors identified that the control logic
associated with the condenser circulating water (CCW) pump
discharge valves was not single failure proof. Loss of the CCW
system would isolate the primary suction flow path for the low
pressure service water (LPSW) pumps.
This issue was discussed in NRC Inspection Report 269,270,
287/93-13. To correct the immediate single failure vulnerability,
the licensee opened the CCW cross connect valves to align multiple
water supplies to the LPSW pumps. Subsequent corrective actions
included performing a single failure analysis on the CCW supply to
the LPSW system, modification of the CCW pump discharge valve
control circuitry to eliminate the single failure vulnerability,
and implementing administrative controls on Keowee lake levels.
The inspector verified that the above actions had been completed.
b.
(Closed) LER 269-93-08, Inappropriate Actions Result In Loss Of
Vital Power Panelboard And A Reactor Trip
Unit 1 tripped from 100% power on August 23, 1993, when power to a
Unit 1 AC and DC control power panelboard was lost. The power
loss occurred when technicians attempted to switch the
panelboard's power to the alternate source for routine
surveillance. The panelboard's alternate power supply electrical
leads were later found to have been reversed or rolled during
previous maintenance activities. This configuration control error
resulted in the alternate supply's diode arrangement blocking
current flow to the panelboard.
The licensee determined that maintenance technicians had
incorrectly relanded leads during a May 18, 1993, maintenance
activity. Since they were not required to perform continuity
checks or other post-maintenance verifications, the problem went
undetected until the time of the event.
ENCLOSURE 2
15
Corrective actions included revising Maintenance Directive 4.4.13,
I&E Configuration Control Work Practices on November 20, 1993, to
provide specific guidance for marking leads and termination points
during lifted lead evolutions. In addition, a Quality Steering
Team (QST) was formed to review the Post Maintenance Testing
program. As a result of the QST recommendations, a new Nuclear
Station Directive NSD 208, Testing, was issued to provide guidance
for Post Maintenance Testing.
The inspector verified the changes were incorporated into the
Oconee Maintenance program. This item is closed.
8.
Exit Interview
The inspection scope and findings were summarized on June 28, 1995, with
those persons indicated in paragraph 1 above. The inspectors described
the areas inspected and discussed in detail the inspection findings. 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
Inspector Followup Item
Open
269,270,287/95-11-01
Activities (paragraph 3.a.(7))
Violation 287/95-11-02
Open
Failure to Initiate a PIP in a
Timely Manner (paragraph 4.a)
Violation 287/93-31-03
Closed
Failure To Evaluate Materials For
Fire Loading (paragraph 6.a)
Violation
Closed
Inadequate 50.59 Evaluation
269,270,287/93-31-02
(paragraph 6.b)
Violation
Closed
Failure To Follow Procedures To
269,270/93-23-01
Maintain Configuration Control
(paragraph 6.c)
Closed
A Postulated Single Failure During a
LOCA/LOOP May Result In The Loss Of
Post Accident Cooling Due to A
Design Deficiency (paragraph 7.a)
LER 269-93-08
Closed
Inappropriate Actions Result In Loss
Of Vital Power Panelboard And A
Reactor Trip (paragraph 7.b)
ENCLOSURE 2