ML16154A683
| ML16154A683 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 10/12/1994 |
| From: | Steven Rudisail, Shymlock M NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML16154A681 | List: |
| References | |
| 50-269-94-26, 50-270-94-26, 50-287-94-26, NUDOCS 9411010087 | |
| Download: ML16154A683 (12) | |
See also: IR 05000269/1994026
Text
R EGU
UNITED STATES
NUCLEAR REGULATORY COMMISSION
REGION II
101 MARIETTA STREET, N.W., SUITE 2900
ATLANTA, GEORGIA 30323-0199
Report Nos.:
50-269/94-26, 50-270/94-26 and 50-287/94-26
Licensee: Duke Power Company
422 South Church Street
Charlotte, NC 28242
Docket Nos.:
50-269, 50-270, and 50-287
License Nos.:
Facility Name:
Oconee Nuclear Station Units 1, 2 and 3
Inspection Conducted: August 29 - September 2, and
September 12 -
16, 1994
Inspector: 2. -1-7
' 4
S.'Date
Signed
Approved b
1ymoc
,i
/LM.P'Shymlock, W1ief
.t in
Plant Systems Section
Engineering Branch
Division of Reactor Safety
SUMMARY
Scope:
This special announced inspection was conducted to review and assess the
adequacy of corrective actions for a violation, deviations and findings
identified during the Electrical Distribution System Functional Inspection
(EDSFI) of NRC Inspection Report 50-269/93-02, 50-270/93-02, and 50-287/93-02.
Temporary Instruction 2515/111, Electrical Distribution Follow-up Inspection
was used for guidance during this inspection.
Results:
In the areas inspected a violation was identified. In response to Deviation
93-02-01, the licensee issued a procedure to semiannually verify the
corrective action of locking valves open on Keowee cooler heat exchangers.
The licensee had failed to perform this verification. This was identified as
violation 94-26-01 (paragraph 3.4).
Violation 93-02-01, Failure to Classify
Feeder Circuit Breakers as Safety Related was closed. Corrective actions were
Enclosure
9411010087 941013
PDR ADOCK 05000269
2
determined to be adequate. Deviation 93-02-02 was not closed. Corrective
actions identified by the licensee had not been completed. Inspection of
cable identified in the corrective action was not scheduled for completion
until October 31, 1995. A modification to separate cables for 2LP-19 and 2LP
20 was scheduled for the Unit 2 refueling outage EOC14. The findings of the
EDSFI were collectively identified as IFI 93-02-03. The response to these.
findings and the applicable corrective action was reviewed. Most calculations
required to be revised in response to the findings were not complete and
therefore not reviewed. Other corrective actions were also incomplete.
Overall, the inspector considered the progress of the corrective actions to be
slow. These items were addressed in a management meeting between Duke Power
and the NRC on September 29, 1994. At that meeting Duke Power identified a
completion date of November 1995 for the outstanding items associated with the
EDSFI. The inspector closed IFI 93-02-03 to document the items completed in
response to EDSFI findings.
IFI 94-26-02 was opened for further review of
incomplete finding responses.
IFI 93-02-04, Items Identified for Further NRC Review was closed.
Additionally, IFI 93-20-04, Alarm Circuit/Control Circuit Interface was
reviewed and closed. Corrective actions for this item were reviewed and
determined to be satisfactory.
REPORT DETAILS
1.
Persons Contacted
Licensee Employees
- M. Abercrombie,.Keowee Operations
- M. Bailey, Regulatory Compliance
- S. Burton, Keowee Operations
- J. Davis, Engineering Manager
- B. Dolan, Safety Assurance Manager
- T. Grant, Electrical Engineering
- T. Ledford, Supervisor, Electrical Engineering
T. Lee,-Operations Support
- C. Little, Supervisor, Electrical Engineering
M. Miller, Electrical Engineering
- G. Rothenberger, Operations Superintendent
- R. Severance, Mechanical Engineering
BS.
Townsend, Keowee Operations
Other licensee employee contacted during this inspection included
craftsmen, engineers, technicians, and administrative personnel.
NRC Employees
P. Harmon, SeniorResident Inspector
- L. Keller, Resident Inspector
- K. Poertner, Resident Inspector
- Attended exit interview
Acronyms and abbreviations used throughout this report areidentified in
the last paragraph.
2.
Background
During January 25 through March 5, 1993, the NRC conducted the
Electrical System Distribution Functional Inspection (EDSFI).
The
purpose of this inspection was to assess the capability of the Oconee
Electrical Distribution System to perform it functions during operating
and accident conditions.
The conclusion of the EDSFI team was that the
electrical distribution system would perform its intended function
pending further analysis and testing bythe licensee.
During the EDSFI
inspection a violation and several deviations were identified.
Additionally, findings identified during the EDSFI were collectively
identified as IFI 93-02-03.
3.
Review of Corrective Action for Violation and Deviations (TI 2515/111)
The inspector reviewed a violation and three deviations identified at
Oconee during the EDSFI.
These items are discussed in the following
paragraph.
2
3.1
(Closed) Violation 93-02-01, Failure to Classify Feeder Circuit Breakers
as Safety Related, was issued for failure to classify feeder circuit
breakers from the startup transformers to the Reactor Coolant Pump
busses or the 4.16 kV load shed circuit breakers feeding non-safety
related loads as safety related. Duke Power responded to this violation
and denied the examples cited were a violation of NRC requirements.
However, Duke Power agreed to enhance the maintenance and testing of the
subject circuit breakers commensurate with the requirements for safety
related circuit breakers. The NRC responded that the enhancement of the
circuit breaker testing and maintenance would place the licensee in
compliance with the NRC requirements.
The inspector reviewed the licensee implementation of the maintenance
and testing of the circuit breakers as safety related. Nuclear Station
Directive NSD B.1 307, QA Condition Structures, Systems and Components
was revised to require 6.9 kV Switchgear TA and TB to be maintained and
tested as QA-1. The NSD was also revised to require 4.16 kV switchgear
Procedure IP/0/A/2001/003A, Inspection and
Maintenance of 4.16kV and 6.9kV ACB's was also reviewed. This procedure
had been revised to require Quality Control requirements and inspection
of maintenance activities as required for QA-1 components.
Additionally, work orders were reviewed for performance of maintenance
on circuit breakers. Work order 93082223 was issued for maintenance on
circuit breaker 1TE-06. This work order required the replacement of the
puffer tubes on the circuit breaker. The inspector verified that this
work order accomplished the work as required for QA-1 work activities
and the replacement of parts met the requirements for QA-1 work
activities. Violation 93-02-01 was closed.
3.2
(Open) Deviation 93-02-02, Item 1, Deviation from FSAR Color Coding
Requirements for Cables was one of three examples of a deviation
identified during the EDSFI. The first example was identified as power
cables 1XS2 and 1XS48 not being correctly color coded.- These cables run
from the motor control centers 1XS1 and 1XS2 to transformer CT4 cooling
fans.
Final Safety Analysis Report (FSAR) section 8.3.1.3 states that
motor control center (MCC) 1XS1 power and control system cable are color
coded gray and that MCC 1XS2 cables are color coded yellow. Contrary to
this requirement, both cables were color coded black.
The licensee responded to this deviation and agreed that it was a
deviation from the requirements of the FSAR and an oversight during
initial installation. The licensee considered the color coding was
intended to ensure separation during installation. The separation
requirements are for mutually redundant cables to be run in separate
trays. The cables are routed in different cable trays until they reach
the block house of the CT4 transformer. The cable is interlocked armor
type cable. The licensee determined the impact of failure of both
cables and concluded that should they fail the transformer would
continue to operate as designed with only a small impact on transformer
life. Alarms are available to indicate loss of power to the fans and
high oil and winding temperature in the transformer. Operator action
3
would be required upon receipt of alarms. The licensee concluded that
the impact on safety due to the cable being color coded black was
insignificant. The inspector agreed with this conclusion. The licensee
proposed additional corrective action to perform an inspection of all
plant, switchyard, and Keowee cables fed from safety related busses not
previously identified as having mutually redundant safety related
functions. These cables will be inspected to ensure that they are not
routed in the same tray with other cables with redundant functions.
This action is scheduled to be completed by October 31, 1995. This
deviation remains open.
3.3
(Open) Deviation 93-02-02, Item 2, identified mutually redundant cables
for Unit 2 emergency core cooling isolation valves 2LP-19 and 2LP-20 as
being routed in the same cable tray. This was contrary to the
requirements of FSAR section 8.3.1.4.6.2. The licensee agreed that this
was a deviation.
The corrective action for this deviation was to perform a modification
to separate the cables.. Minor modification OE-5990 was prepared to
separate the cables. This modification was scheduled to be performed
during Unit 2 refueling outage (RFO) (EOC14) scheduled for the fall of
1994. The inspector reviewed this modification and the scope of work to
be accomplished during its performance. This modification will
accomplish the required corrective action. Inspection of Unit 1 and
Unit 3 cable for valves LP-19 and LP-20 were performed and the
separation problem did not exist. The licensee proposed additional
corrective action to perform an inspection of all plant, switchyard, and
Keowee cables fed from safety related busses not previously identified
as having mutually redundant safety related functions. These cables
will be inspected to ensure that they are not routed in the same tray
with other cables with redundant functions. This action was scheduled
to be completed by October 31, 1995. This deviation will remain open
pending completion of the modification and inspection.
3.4
(Closed) Deviation, 93-02-02, Item 3, identified examples of heat
exchanger cooler piping that did not have a provision for relief of
overpressure. United States of America Standards (USAS) 831.1, section
101.4.2 requires either design of the piping to withstand overpressure
conditions or a means of pressure relief be provided. FSAR section
3.2.2.2 established the design criteria for Keowee system cooler piping
as USAS B 31.1.0 section 101.4.2. The Keowee turbine guide bearing oil
cooler, generator thrust bearing cooler, and generator air coolers were
not designed with the ability.to withstand increased pressure in an
isolated mode. The licensee agreed that this was a deviation.
The proposed corrective action was to lock open the outlet valves in
accordance with Operation Management Procedure (OMP) 1-17.
This
requires semi-annual verification that the valves are locked. To
accomplish this verification, a new procedure was prepared and issued to
provide for semiannual verification of the locked valves. Keowee
procedure OP/A/2000/45, Lock Verification was issued to accomplish this
action. During this inspection the inspector reviewed the results of
4
the semi-annual verification of lock position. The licensee had not
performed the procedure since issuance on June 29, 1993, and had no
record of its performance at the time of issuance. The procedure was
performed September 1, 1994, following this determination. The
inspector reviewed the results of the procedure and confirmed that the
valves required to be locked open were in the appropriate locked
position. This was identified as Violation 94-26-01, Failure to
Accomplish Procedure for Corrective Action. This example of the
deviation was closed.
4.
Review of Inspector Follow-up Items (IP 37550)
The inspector reviewed the items identified at Oconee as Findings.
These items are discussed in the following paragraphs.
4.1
(Closed) IFI 93-02-03, EDSFI findings consisted of six findings with
several issues identified in each finding. Finding 1 of the IFI
identified a lack of integrated testing for the Oconee emergency power
system and a lack of testing to demonstrate the design capability of the
power source. Several features of the.emergency power source had not
been tested. The overhead path from Keowee and the switchyard isolation
relays of the Emergency Grid Protection system had not been tested. The
Keowee Hydro Emergency Start test procedure PT/0/A/0620/16 was
identified as not performing tests in accordance with FSAR section
8.3.1.1.1. Also, the composite of all Keowee testing was identified as
not bounding the design requirements.
The licensee response to Finding 1 was reviewed by the inspector.
Testing of the switchyard isolation relays has been accomplished.
During the subsequent RFO for Unit 2, test procedure PT/0/A/0610/022 was
performed on May 22, 1993.
The NRC witnessed this testing as documented
in NRC Inspection report 50-369, 270, 287/93-19. This was an integrated
test of the overhead power path which included the isolation relays.
The second channel of the switchyard isolation relays was tested during
the RFO for Unit 1 on May 24, 1994. These test results were reviewed
with no discrepancies identified.
FSAR section 8.3.1.1.1 states that each Keowee hydro unit generator is
equipped with a volt-per-cycle limiting feature which permits it to
accept full emergency power load as it accelerates from zero to full
speed. The licensee addressed the NRC concern that this FSAR
requirement was not being met by the present mode of testing. Procedure
PT/0/A/0620/016 verifies that the Keowee unit will reach rated speed and
voltage within the required 23 seconds as required by the FSAR. This
test was performed annually. The ability to reject load and separate
from the grid was demonstrated every RFO since January 1992, by
PT/0/A/0610/O1J. This test also demonstrates the ability to reconnect
to the overhead power path and properly align the underground path. The
results of PT/0/A/0610/01J prior to 1987 were provided to demonstrate
the ability to accept loading and accelerate to full speed and voltage
as required.
PT/0/A/0610/022 was performed to demonstrate the ability
to place loads on the generators which exceed the emergency loads. This
5
II
procedure loaded a Reactor Coolant Pump onto the Keowee unit. This load
was measured as 9 MVA steady state and 47 MVA inrush.
The inspector concluded the testing described above satisfactorily
demonstrated the ability of the Keowee units to meet their design
requirements. Finding 1 of IFI 93-02-03 was closed.
4.1.1
Finding 2 was an identification of analyses, studies and
calculations which were not complete or had not been performed.
There were ten elements identified in this finding. Only one
element will be closed.
Item 1 of this finding identified that calculation OSC-2059, 4160
Voltage Study, may not have bound the worst case. The revision to
this calculation was not complete. This item will remain open.
Item 2 identified that no analysis or test was available to verify
the rapid transfer timing was correct. An analysis was scheduled
to document transfer adequacy. This analysis was not complete.
Item 2 of this finding will remain open.
Item 3 identified that a transient voltage study for the 4kV
safety loads when supplied by the Lee or Central substation was
not available. The licensee responded that a calculation to
demonstrate dynamic modeling of the Lee and Central power sources
would be completed. During this inspection this item was not
complete. This item will remain open.
Item 4 identified that a study to review control cable length and
the size of fuses that protect them had not been conducted. The
licensee responded that the load study calculation of OSC-2059
would address fuse adequacy. This item was not complete during
the follow-up and this item will remain open.
Item 5 identified that the Kewoee 600V Auxiliary Power System
Voltage Analysis did not evaluate maximum and minimum expected
voltages. The licensee planned calculation KC-UNIT-1-2-0095 to
address voltage adequacy in the auxiliary power system. This item
was not complete and will remain open.
Item 6, concerned the lack of an analysis to support that the
Keowee auxiliaries would not be damaged by overvoltage or
overfrequency when supplied by one Keowee unit. The inspector
reviewed the actions completed for this finding. One calculation
had been completed. The calculation to demonstrate the effect of
overvoltages and overfrequencies on the Keowee auxiliaries was
complete. The calculation OSC-5701, Oconee Keowee Overhead Path
Analysis identified weaknesses that limit the percent power the
Keowee units can generate to .the grid and the alignment of the
Keowee units. These concerns are being addressed in modification
NSM 52966 currently being reviewed by NRC. This item will remain
open.
6
Item 7 identified the need for the full scope and completion of
component calculations for Keowee. Calculations to resolve this
item were not complete. This item will remain open.
Item 8 identified the lack of an analysis to support the
assumption that Oconee safety loads could properly perform during
an overfrequency transient lasting 40-50 seconds. The licensee
plans to complete an analysis to support this assumption. This
item is not complete and will remain open.
Item 9 of this finding identified that calculations for the Safe
Shutdown Facility are not complete. These calculations are
scheduled for completion by December 1994. This item will remain
open.
Item 10 identified the need for more rigorous testing of the
minimum required pickup voltage for components of the Switchyard
125 VDC system to support calculations.
Calculations had
demonstrated acceptable voltage levels at each component with the
exception of one case. This case was the pickup voltage to the
Cutler Hammer Type M relay. The licensee now purchases the type M
relays from a third party supplier. Test results are provided
which document ability of the relays to operate within the range
of voltage determined from the Oconee calculation.
The inspector
reviewed this documentation. This item was closed.
Other calculations and studies required for completion of the
actions addressing this finding were in various stages of
development. The inspector did not review draft calculations.
Theses items are all scheduled for completion by November 1995 and
will be reviewed after that date.
These incomplete actions
addressing this finding are identified as Inspector Follow-up
Item, IFI 94-26-02,
EDSFI Finding Items Not Closed During Follow
up Inspection.
4.1.2
Finding 3 identified examples of inadequate control of drawings
and setpoint documents. Inaccuracies were identified in Keowee
mechanical support system flow diagrams and drawings of Keowee air
systems were not available.
The inspector reviewed the corrective actions for the drawing
deficiencies. The following drawings were reviewed: KFD-105A
1.1, Unit 1 Flow Diagram of Governor Oil System, KFD-105A-2.1,
Unit 2 Flow Diagram of Governor Oil System, KFD-101A-1.1, Unit 1
Flow Diagram of the Turbine Guide Bearing Oil System, KFD-101A
2.1, Unit 2 Flow Diagram of the Turbine Guide Bearing Oil System,
KFD-103A-1.1, Unit 1 Flow Diagram of High Pressure Oil System,
KFD-103A-2.1, Unit 2 Flow Diagram of High Pressure Oil System,
KFD-100A1.1, Unit 1 Flow Diagram of Turbine Generator Cooling
System, and KFD-100A1.1, Unit 1 Flow Diagram of Turbine Generator
7
Cooling System. All drawings had been revised to correct the
deficiencies identified during the EDSFI inspection. Finding 3,
item 1 was closed.
Item 2 of this finding noted that bulletins, information notices.
and generic letters had not been reviewed for applicability to
Keowee: The licensee initiated a comprehensive review of
operating experience documents for applicability to Keowee. This
review was completed and actions items have been identified for
any missed items discovered during the review. This item was
scheduled for completion by November 1995 and will remain open.
Item 3 identified that there was not a controlled setpoint
document available at Keowee except for electrical relay settings.
Corrective actions for this item are not complete.
This portion
of the finding will remain open.
4.1.3
Finding 4 identified areas where additional licensee actions were
warranted to complete corrective actions.
Item 1 of this finding
was that the response to the Keowee governor system to postulated
failures was not fully analyzed.
Item 2 of this finding
identified that implementation of a setpoint revision to the Loss
of Field relay at Keowee had not been completed.
The inspector reviewed minor modification OE-6215 which
implemented a setpoint change for the Loss of Field relay in
accordance with the results of design calculation, OSC 4300.
Item
2 of Finding 4 was closed.
The licensee responded to the concern that postulated failures of
the Keowee governor had not been analyzed. The Keowee governor
system single failure analysis had been completed. An enhancement
to the governor's availability was still under review. A
modification to add a DC powered governor oil pump was being
planned.
Item 1 of Finding 4 will remain open.
4.1.4
Finding 5 identified Keowee engineering analyses which were not
sufficiently comprehensive and specific values had not been
established that would bound design criteria. All credible
failure modes for the Keowee governor control system and the
voltage regulator had not been considered. The basis for
bypassing trip functions during emergency start of the Keowee unit
was not fully analyzed or documented. The effect of frequency of
the electric power supplied by Keowee to ECCS pump motors had not
been fully evaluated and acceptable voltage and frequency
limitations for Keowee electrical auxiliaries and the emergency
power system should be defined.
The inspector reviewed calculation KC-Unit 1-2-0098, Keowee
Governor Mechanical Single Failure Analysis. The analysis
methodology did not differ from the original memorandum to file
reviewed during the EDSFI that documented the results of the
8
single failure review of the governor. The licensee initiated a
design study to further examine the bypassing of trip functions
during an emergency start. This study was not complete at the
conclusion of thi.s inspection. Finding 5 will remain open.
4.1.5
Finding 6 identified design features and mechanical components at
Keowee that were not being tested. Weaknesses were identified in
the testing of lubricating oil systems at Keowee. Pressure
switches in the carbon dioxide fire protection system were not
being tested or calibrated. Valves which were required to change
position for Keowee to provide emergency power were not included
on the Keowee active valve list. These valves were 1 and 2 OG-7
which were the float valves for the governor oil tank and the
check valves of the ACB air accumulators. Weaknesses were
identified in the testing procedures associated with ACBs 1, 2, 3,
and 4.
The inspector reviewed the corrective action for this finding.
Procedure IP/1/A/0400/023, Unit No. 1 C02 Fire Protection Pressure
Switch Calibration and IP/2/A/0400/023, Unit No. 2 C02 Fire
Protection Pressure Switch Calibration were developed for the
calibration of the pressure switches in the Kewoee fire protection
system. Procedure MP/O/A/2000/059, Periodic Test of the C02
System Generator No. 1 and Procedure MP/O/A/2000/060, Periodic
Test of the C02 System Generator No. 1 were developed for testing
of the Kewoee fire protection system. These procedures are
implemented and were reviewed and the inspector did not identify
any concerns. Minor modifications OE-5586 and OE-5597 had been
completed to install the necessary valves and test tee for testing
of the fire protection system. These modifications were reviewed
and no problems were identified.
The inspector also reviewed completed work orders for the testing
of oil level switches in the Keowee system. These work orders had
been completed to ensure that all oil level switches in oil
systems effecting operability at Keowee were calibrated. The
inspector found the calibrations satisfactory.
Procedure revisions to remove weaknesses from the procedure for
testing the Keowee Air Circuit Breakers was not complete. The
actions to determine which Keowee equipment will be added to the
Inservice Testing (IST) program was still incomplete. These
incomplete actions will be identified under IFI 94-26-02.
4.2
(Closed) IFI 50-269/93-20-04, Alarm Circuit/Control Circuit Interface
(IP 92701)
The inspector reviewed IFI 93-20-04 which was opened after Unit 1
experienced a turbine driven emergency feedwater pump (TDEFWP) auxiliary
oil status alarm in the control room. Investigation of the problem by
Work Order 40704C revealed blown fuses in the TDEFWP auxiliary oil pump
start circuit. The TDEFWP was declared inoperable because the automatic
9
start feature of the pump was defeated if the auxiliary oil pump is out
of service. The cause of the blown fuses was identified as a shorted
alarm relay AR-15. Problem Investigation Process (PIP) No. 1-093-0545
was opened to determine corrective action for this problem and track its
resolution.
The inspector reviewed the corrective actions associated with the PIP.
A modification to add parallel fuses across the existing fuses was
completed on Unit 1 and 3 by minor modification OE-6080 and minor
modification OE-6082 respectively. Minor modification OE-6081 was
outstanding for Unit 2. The modification prevented a blown fuse in the
indication portion of the circuit from disabling the pump start circuit.
IFI 93-20-04 was closed.
7.
Exit Meeting (IP 30703)
The inspection scope and results were summarized on
September 16, 1994, with those individuals indicated in paragraph 1.
The inspector described the areas inspected and discussed in detail the
inspection findings. There was no dissenting comments received from the
licensee. Proprietary information is not contained in this report.
(Opened)
Violation 50-269/94-26-01, Failure to Perform Procedure as
Corrective Action
(Opened)
Inspector Follow-up Item,-IFI 94-26-02, EDSFI Finding Items
Not Closed During Follow-up Inspection
(Closed)
Inspector Follow-up Item, IFI 93-02-03, EDSFI Findings
(Closed)
Inspector Follow-up Item, IFI 93-02-04, EDSFI Items
Identified for NRC Review
(Closed)
Inspector Follow-up Item, IFI 93-20-04, Alarm
Circuit/Control Circuit Interface
0I
10
8.
Acronyms and Abbreviations
C02
Carbon Dioxide
EDSFI
Electrical Distribution System Functional Inspection
Inservice Testing
IP
Inspection Procedure
KFD
Keowee Flow Diagram
kV
Kilovolts
Motor Control Center
MVA
Mega Volt Amperes
NRC
Nuclear Regulatory Commission
Nuclear Reactor Regulation
NSD
Nuclear Station Directive
Quality Assurance
Refueling Outage
TDEFWP
Turbine Driven Emergency Feedwater Pump
VDC
Volts Direct Current