ML18153B325
| ML18153B325 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 09/17/1993 |
| From: | Julian C, Shymlock M NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML18153B324 | List: |
| References | |
| 50-280-93-21, 50-281-93-21, NUDOCS 9309280171 | |
| Download: ML18153B325 (14) | |
See also: IR 05000280/1993021
Text
Report Nos. :
UNITED STATES
NUCLEAR REGULATORY COMMISSION
REGION 11
101 MARIETTA STREET, N.W.
ATLANTA, GEORGIA 30323
50-280/93-21 and 50-281/93-21
Licensee: Virginia Electric and Power Company
Glen Allen, VA
23060
Docket Nos.:
50-280 and 50-281
Facility Name:
Surry 1 and 2
License Nos.:
Inspection Conducted: August 16-20, 1993
Inspector:---:~.,...--=---*
..... ~----.-*-~o/~~b--:----=-~-~~~~~~~~~~
M. Shymlock,'~hief
Plant Systems Section,
Division of Reactor Safety
Accompanying Personnel:
R. Moore
S. Rudisail
N. Salgado
Approved by: cL,,L~
'
~*c. Juli an, Chief
Engineering Branch
Division of Reactor Safety
SUMMARY
Scope:
~;_/6-93
Date Signed
Date Signed
This routine, announced, reduced scope inspection of the licensee's EDS was
conducted to assess the corrective actions taken and planned in response to
findings identified during their self-assessments. The adequacy of the
licensee's assessment process was also reviewed.
Results:
The inspection concluded that the licensee's EDSFA was adequate to assess the
design and functional capability of their EDS.
The independent review
verified the licensee's conclusion that the EDS met it's design and functional
capability.
EDSFA findings were adequately identified, tracked, and addressed
for corrective actions.
In the areas inspected, violations or deviations were not identified .
9309280171 930917
ADOCK 05000280
G
REPORT DETAILS
1.
Persons Contacted
2.
Licensee Employees
- R. Bilyeu, Licensing Engineer
- H. Blake, Supervisor, Design, Electrical Engineering
- R. Blount, Superintendent, Station Engineering
- A. Brown, Supervisor, Nuclear Training
- D. Christian, Assistant Station Manager, Operations and Maintenance
- R. Cross, Coordinator, Nuclear Procedures
- J. Downs, Superintendent, Outage and Planning
- G. Flowers, Manager, Nuclear Electrical Engineering
- D. Georgianna, Supervisor, Systems Protection
- G. Jones, Design, Electrical Engineer
- A. Keagy, Superintendent, Station Materials
- J. LaFlam, System Engineer
- J. McCarthy, Assistant Station Manager, Nuclear Safety & Licensing
- W. McCloskey, Supervisor, Design, Mechanical Engineering
- D. O'Connor, System Engineer
M. Phillips, Electrical Engineer
- R. Rasnic, Corporate Supervisor, Mechanical Engineering
J. Ruddy, Senior Electrical Engineer
- V. Shifflett, Licensing Engineer
- E. Smith, Jr., Manager, Quality Assurance
- W. Stallings, Corporate Supervisor, Electrical Engineering
- J. Surface, Senior Staff Engineer
- G. Thompson, Superintendent, Maintenance (Acting)
- J. Waddil, Staff Engineer, Mechanical
Other licensee employees contacted during this inspection included
craftsmen, engineers, operators, and technicians.
NRC Employees
- M. Branch, Senior Resident Inspector
- Attended Exit Interview
Acronyms and abbreviations are listed in the last paragraph.
Introduction
In a letter to the NRC dated June 3, 1993 the licensee requested that the
Electrical Distribution System Functional Inspection (EDSFI) scheduled
for Surry be waived.
The licensee indicated that prior to the EDSFI at
North Anna their Corporate Nuclear Safety (CNS) group, with assistance
from outside consultants, performed an internal EDSFA at North Anna.
Following that effort and the NRC's EDSFI at North Anna, the CNS group
performed a similar assessment of Surry's electrical distribution system.
That assessment included applicable questions and the lessons learned
3.
2
from the NRC's EDSFI and their own internal assessment of North Anna.
Based on this effort a corrective action tracking database for these
issues was developed. This database has been used to track the
resolution of these issues as well as other electrical issues that were
identified.
During the week of June 28, 1993, the Section Chief of the Plant Systems
Section in the Division of Reactor Safety in Region II visited the
licensee's facility. This visit was for the purpose of reviewing the
licensee's self-assessment and to look at some corrective actions.
Further discussions on this matter were conducted with selected licensee
staff and NRC Management in the Regional Office on July 28, 1993. A
decision was made by NRC Management to reduce the scope of the EDSFI at
Surry.
Conclusions
The licensee's self-assessments were well developed and performed by
knowledgeable individuals. The scope of the EDSFA was similar to that of
the NRC's EDSFI Temporary Instruction 2515/107.
It was concluded that
the scope of the EDSFA was adequate to assess the design and capability
of the EDS.
Independent reviews of specific aspects of the EDS were
performed by the inspectors and verified the adequacy of the licensee's
conclusions. A strength was noted in the area of interface between
station and substation personnel in communication and control of work
activities in the switchyard.
The inspectors reviewed the EDSFA results and corrective actions taken
since the conclusion of the EDSFA.
Overall, the licensee has responded
to the EDSFA findings satisfactorily. The licensee was continuing to
assess the status of corrective actions and calculation revisions to
enhance the design of the EDS at Surry.
The licensee developed a database system that categorizes the identified
issues into six areas (Calculations, Procedural, Programmatic, Setpoint,
System Design, and Documentation).
The database is used to track
completion of corrective actions. It includes EDSFA issues, North Anna
EDSFI questions, and self-identified electrical issues. This is a very
useful system.
At the end of the inspection the corrective action status
of the 791 identified issues indicated that only 55 remained open.
The EDSFA scope was adequate to assess the adequacy of the design and
functional capability of the EDS mechanical support systems.
Findings
were appropriately identified, tracked, and addressed for corrective
actions. Mechanical systems were adequately designed and maintained to
support the EDS.
Accident equipment electrical loads were properly
determined.
The emergency diesel generator load testing performed in 1989 was
identified as a strength. The inspector noted however, that no endurance
testing has been accomplished for the EDGs to challenge their capability
for an extended run at rated load.
3
A weakness was identified in the fuel oil chemistry monitoring program in
that particulate analysis of the oil did not provide a specification or
action level. The inspector noted an example where this parameter
exceeded typical values and no actions were taken.
Calculations were not available to verify that all safety related equip-
ment spaces' ambient temperatures did not exceed equipment specifi-
cations. This was identified by the licensee and corrective actions were
in progress.
Review of bounding conditions indicated no apparent
operability concerns.
The EDSFA evaluation of EDS seismic applications was rigorous and
findings were adequately addressed.
4.
EDS Review
The inspectors reviewed the electrical calculations. The calculations
were reviewed with respect to the corrective actions to findings identi-
fied in the EDSFA or in the calculational upgrade program being performed
by the licensee. Limited system walkdowns were performed to assess
material conditions of the EDS.
4.1 Offsite Power System
The licensee conducted a Switchyard Equipment Reliability Assessment
between May 1992 and September 1992. This assessment included the
review of electrical equipment, transmission and distribution
interconnecting lines, and protective relaying equipment in the
switchyard. This effort was performed by Commercial Operations
personnel who were knowledgeable in this field. Their goal was to
identify switchyard equipment conditions and problems that may
affect the overall reliability of the switchyard. The inspectors
reviewed this effort and some corrective actions identified to
address specific concerns. This assessment was very thorough,
complete and objective. The corrective actions were being properly
implemented.
The follow-up of the CNS Switchyard Follow-up Assessment dated
April 28, 1992, was also reviewed. It was noted that the site and
Substation Maintenance had taken corrective actions to address
specific concerns and recommendations identified in the assessment.
A strength was noted in the area of interface between station and
substation personnel in communication and control of work activities
in the switchyard.
Several modifications to the switchyard electrical distribution
system at Surry were referenced in the request from the licensee to
waive the EDSFI inspection at Surry.
One of these modifications was
the 34.5 kV Bus No. 5 Modification.
Due to an event which occurred
in the switchyard on August 26, 1991, the Substation and Protection
Department was assigned the task of evaluating the switchyard
configuration and making recommendations if improvements were
\\.
4
warranted.
The resulting evaluation identified two problems which
needed correction. The first problem identified was with the
existing switchyard configuration. This configuration resulted in a
fault on the switchyard Station Service Transformer No. 1 (SSTX#l)
secondary causing activation of plant emergency systems.
The second
problem identified was that the SSTX#l was directly connected to Bus
- 5 without a means of disconnect. This was disadvantageous because
personnel would be required to enter the switchyard to physically
isolate SSTX#l from Bus No. 5 in the event of a failure of the
transformer. This results in additional time with the Reserve
Station Service Transformers out of service.
As a result of the
identification of these problems, a Design Change Package was
developed to evaluate and document switchyard modifications to
eliminate the problems.
The modification to address these problems involved the
reconfiguration of 34.5 kV switchyard Bus #5.
SSTX#l was changed to
an open-wye open-delta connected transformer.
This reconfiguration
included adding a grounding transformer to the secondary of the 500
kV to 34.5 kV transformer No. 1, and installing a set of load break
fused cutout switches between 34.5 kV Bus No. 5 and the primary
bushings of SSTX#l.
This allows disconnection of SSTX#l from the
Bus No. 5.
r
4.2 Onsite Electrical Systems
Medium Voltage System Calculations
The inspectors reviewed calculation EE-0034, Surry Voltage Profiles.
This calculation was recently completed to verify and document
sufficient starting and running voltages existed at the emergency
4.16 kV and 480 V busses. This calculation superseded previous
calculations.
Calculation EE-0034 was developed from Auxiliary Design Optimization
Program (ASDOP).
The inspector reviewed this calculation to ensure
that the results demonstrated adequate voltage for the 4.16 kV and
480 V distribution systems for the system alignments modeled.
During the review of the calculation the inspectors expressed
concern for a system alignment in which the calculated voltage level
had a narrow margin. This narrow voltage margin was on the 480 V
Bus lJ which supplied the containment spray and low head safety
injection pumps.
The calculation demonstrated an available voltage
of 348.97 V.
The required starting voltage was 348.83.
The
inspector requested further examination of this voltage calculation.
The inspector determined that the calculation contained both
conservative and non-conservative assumptions and could not justify
the acceptance of the narrow margin.
The low head safety injection
pump is a 300 hp motor. This was previously a 250 hp motor but when
the pump motor was replaced the smaller size was not available .
This additional load on the bus resulted in the narrow voltage
5
margin.
Licensee engineering personnel had analyzed the voltage
torque-speed curves for the 300 hp pump motor and determined the
motor would accelerate the load at this calculated voltage.
Discussion with licensee personnel indicated that if the required
starting voltage was not available initially, sufficient voltage
would be available prior to the protective devices tripping the
breaker for this motor.
Licensee personnel generated an additional
computer run that demonstrated that once the high head safety
injection pump started on the 4.I6 kV bus, voltage levels would
increase on the 480 V bus to ensure that the lowhead safety injec-
tion pump and the containment spray pump would have sufficient
starting voltage prior to any breakers tripping. The inspectors
agreed that this adequately resolved the voltage concerns of this
calculation.
The inspectors reviewed calculation EE-0502, 4.I6 kV Degraded
Voltage and Undervoltage Relay Setpoints.
EE-0502 determined the
4.I6 kV degraded voltage and loss of voltage relay setpoints for the
4.I6 kV emergency busses.
The original basis for these degraded
voltage and undervoltage setpoints was developed by Stone and
Webster Engineering Corporation {SWEC).
The SWEC calculation relied
on assumptions and did not investigate the influence of voltage
drops down to 480 V Motor Control Center {MCC) loads in sufficient
detail. The licensee revised the degraded voltage section of
EE-0502 to ensure that there was adequate voltage to pick-up all
contactors in the Class IE MCCs, and the minimum continuous running
voltage was supplied to all Class IE motors on the medium and low
voltage emergency busses.
EE-0502 concluded that the degraded
voltage setpoint could be increased to improve motor terminal
voltages.
EE-0502 was being revised to reflect the recommendation.
The licensee will properly coordinate the revision of EE-0502 with
the revision of calculation EE-0034, Surry Voltage Profiles. Until
the TSs are amended to reflect a new degraded setpoint, the 480 V
loads' terminal voltages range from 85% to 90% of rated voltage.
These terminal voltages result when the 4.I6 kV bus voltage is at
the degraded voltage setpoint minus the Channel Statistical Analysis
{CSA).
The licensee determined that the motors are still operable
because no overload protection would activate in this voltage range.
The licensee's calculation revision also concluded that the loss of
voltage setpoints were adequate for the existing setting. The
inspectors identified no deficiencies with the ongoing revision of
EE-0502.
The inspectors reviewed calculation EE-0334, Surry Emergency Bus
Fault Current Analysis.
This calculation provided an updated
review of available fault currents on the emergency 480 V and 4.I6
kV systems for comparison to the existing MCC, loadcenter and
switchgear duty ratings. This calculation was performed using the
ASDOP software. The results of this calculation indicate that the
4.I6 kV switchgear breakers are adequately sized to interrupt the
calculated fault currents. For the 480 V system, the calculations
6
demonstrated adequate breaker interrupting ratings for the 480 V
load centers. However, for the 480 V MCCs the calculation demon-
strated that the available fault current exceeded the ratings of the
The circuit breakers were rated at
14,000 A interrupting capacity. They are Westinghouse type FA and
FB circuit breakers.
The calculated fault current was 19,029 A for
a maximum MCC bus voltage of 506 V.
The licensee had conducted a study which determined the
manufacturer's ratings for these breakers was conservative. Actual
ratings for these breakers was 16,600 A for the breaker only.
With
the circuit breaker in combination with a motor starter the
interrupting capacity was 19,000 A.
The results of the study have
been presented to the NRC for consideration. The same issue exists
at the North Anna Power Station. A study with similar conclusions
was also performed for the North Anna Power station. Both of these
studies will be reviewed further by the NRC.
Calculation EE-0372, Surry Non-emergency Bus Fault Current Analysis
was also reviewed. This calculation computed the available faults
for the 4.16 kV and 480 V non-emergency busses.
The results demon-
strated adequate interrupting ratings for the non-emergency power
system with the exception of some molded case circuit breakers.
The
same concern for available interrupting capacity existed on these
breakers as in the 480 V emergency system discussed in the previous
paragraph.
The inspectors reviewed the coordination and protection scheme for
the AC Distribution system. Calculations EE-0335, Relay Settings
for Feeder Breakers on Busses lH and lJ (4160 V), -EE-0313, Relay
Settings for the Protection of Safety Bus lJ at Surry, and EE-0312,
Relay Settings for the Protection of Safety Bus lH at Surry were
reviewed.
The results of these calculations demonstrated adequate
relay setting for acceptable coordination. The licensee's engineers
are considering a revision to the settings of these relays on busses
lH and lJ to improve the coordination of the stub bus breakers with
the EDG output breakers.
The inspectors considered that the review
of these relay settings was satisfactory.
Calculation EE-0497, Safety Related 480 V Load Center Coordination
was performed to review and document the overcurrent protection and
coordination for the 480 V safety related load centers. The
licensee concluded that adequate coordination exists. Several
instances of miscoordination were identified in the calculation but
were not determined to be safety significant. The inspectors agreed
with this determination.
Low Voltage DC System Calculations
The inspectors reviewed calculation EE-0499, DC Vital Bus Short
Circuit Current. The purpose of EE-0499 was to evaluate the maximum
fault current on the 125 VDC busses. Charger contributions and
7
maximum electrolyte temperature effects were included when
determining the worst case fault currents.
EE-0499 was initiated to
re-evaluate the fault currents calculated in SWEC calculation
14937.16-E-l, DC Vital Bus Short Circuit Current.
The worst case
fault current calculated was 19,745 A on Bus 28 with two chargers
connected. The results of EE-0499 concluded that under normal plant
operating conditions, the fault currents available to the DC busses
are within the breaker's interrupting ratings.
The licensee's EDSFA identified a concern with the fault current
available when all four UPSs and one battery are connected to the
cross-tied busses.
The fault current available from the four UPSs
was calculated to be 1752 A.
If the cross-tie breaker was closed
this bus would be exposed to the fault contribution of four
chargers, and would allow a current of 20621 A on DC Bus 28. This
would exceed the manufacturer's rating of 20,000 A at 250 VDC for
the breakers. The licensee did not consider this to be an unsafe
condition because the Westinghouse data sheets for the HFB breakers
indicated an interrupting rating of 20,000 A at 250 VDC.
The
breakers at Surry are used in a 125 VDC application.
The licensee
concluded that since interrupting ratings have an inverse
relationship to voltage, a rating higher than 20,000 A would be
available when applied on 125 VDC.
Westinghouse indicated to the
licensee that the HFB breakers were capable of safely interrupting
faults in excess of 20550 A at 125 VDC.
The calculation was
conservative because cable resistances for the cables fed from the
feeder busses to the chargers were not considered in the fault
study. This resistance would lower the fault contribution from the
chargers.
Thus the calculation approach and the breaker's
interrupting rating was adequate.
The inspectors reviewed calculation EE-0046, Surry VDC Loading
Analysis.
The purpose of EE-0046 was to verify the actual loading
on each 125 VDC Distribution Cabinet, confirm battery sizing, and
determine voltage levels at the distribution panels. The load cycle
determined by EE-0046 differed from the calculations which were used
to originally size the station batteries. However, the batteries
were still adequately sized* to satisfy the load cycle required at
the station under a worst case accident condition. The calculation
concluded that the voltage levels for the 125 VDC system are capable
of operating the station equipment as required.
The inspectors con-
cluded that EE-0046 demonstrated that adequate voltage was available
for the 125 VDC system. It was also noted that the 125 VDC
Calculation Upgrade Program (CUP) will develop a detailed model of
the 125 VDC system including loads, load parameters, load operating
requirements for the station batteries. The model will include the
battery duty cycle, voltage drops, fault currents, jumpered cell
analysis, and input to the battery charger sizing analysis.
The inspectors noted that the licensee had installed a non-safety
battery~ This battery is located in a separate building outside'the
turbine building. The battery installation reduced the previous
8
loading of the station's vital batteries by assuming some of the
non-safety loads.
The licensee designated this particular battery
as the "Black Battery". The inspectors assessed that this was a
good approach to increase the load margin on the station's vital
batteries. The inspectors also conducted a limited walkdown
inspection of the black battery room and no problems were
identified.
The inspectors reviewed calculation EE-0493, Black Battery Short
Circuit Duty. The purpose of EE-0493 was to evaluate the maximum
fault current at the*black battery.
EE-0493 was initiated to re-
evaluate the fault currents which were included in older SWEC
calculations. EE-0493 included fault current contributions from the
battery chargers, the emergency oil pump, and the air side seal oil
pump.
The breakers located on the black battery busses have an
interrupting rating of 20,000 A at 250 VDC, and have been previously
determined to have an interrupting rating of at least 20,000 A at
125 VDC.
The calculation concluded that the maximum available fault
current including motor and charger contributions with the maximum
electrolyte temperature effects was 16764.40 A at the 125 VDC
distribution cabinet 1-1.
The licensee concluded that the fault
currents calculated were less than the interrupting ratings of the
circuit breakers. Therefore, the 125 VDC protective devices had
adequate interrupting capacities. The inspectors also noted that
the 125 VDC CUP model will also include the black battery .
5.
MECHANICAL SYSTEMS
The inspector reviewed the mechanical area of the licensee's EDSFA to
determine if the scope was adequate to appropriately assess the design
and functional capability of EDS mechanical support systems.
The EDSFA
findings and associated corrective actions were reviewed.
Additionally
the inspector accomplished an independent review of various mechanical
areas such as accident equipment electrical loads, Emergency Diesel
Generator (EDG) maintenance and testing, and fuel oil chemistry
monitoring.
Documents reviewed included the licensee's EDSFA, EDSFA
follow-up report, Updated Final Safety Analysis Report (UFSAR),
maintenance procedures and documentation, mechanical system calculations
and design information.
5.1 Accident Equipment Load Values
The inspector reviewed the licensee's calculations for accident
equipment electrical load values for safety related pumps and fans.
These values provided input to the EDG loading calculations.
Calculation EE-0035, EDG Loading Analysis, revision 1, listed
equipment load values. Calculation EE-0029, Surry Electrical Load
List, revision O, provided the basis for these load values and
included safety related pump and fan curves.
The inspector verified
accident flow values with the Design Basis Documents (DBDs) and the
5.2
9
The inspector concluded that the accident equipment load
values were appropriately determined and input to the EDG load
calculation.
EDG Testing and Maintenance
The inspector reviewed the licensee's design and test documentation
which verified the EDG capability to meet its design load require-
ments. Additionally, the inspector reviewed maintenance activity on
the EDGs.
The licensee conducted comprehensive load testing with
resistive load banks in 1989 to verify accident loading capability.
Calculation EE-0045, EDG Voltage and Frequency Response, revision 0,
documented EDG response characteristics to worst case loading. This
test verified the EDG ability to provide adequate starting and
running voltages for safety related equipment.
The EDG frequency
and voltage criteria of Regulatory Guide 1.9, Selection, Design, and
Qualification of Diesel Generator Units Used as Standby Electric
Power Systems at Nuclear Power Plants, revision 2, were used as
acceptance criteria for testing.
The load testing was accomplished on EDG 3 and equivalency of EDGs 1
and 2 was verified. Equivalency was established by performance of
maintenance and minor modifications recommended by the EDG vendor,
Morrison-Knudsen.
Primarily, the voltage regulators were calibrated
and tested and the governors were modified to assure equivalent
response.
The equivalency was documented in Report No. 5714-2R,
Maximum Cold Diesel Load Carrying Capability, revision I, by
Morrison-Knudsen.
The vendor recommended a restriction on initial
loading of the EDG to account for cold start conditions. It was
recommended that the pressurizer heater load be delayed for two to
three minutes.
The licensee delayed the loading of pressurizer
heaters for 180 seconds.
The inspector reviewed the load sequencing
logic for the heaters and verified that the load was delayed 180
seconds.
The inspector concluded that EDG load capability testing
was a strength.
The inspector noted that no endurance testing had been accomplished
for the EDGs to assure their capability to run at rated load for an
extended period of time, as could be required in an accident
condition.
The longest documented continuous run was 18 hours2.083333e-4 days <br />0.005 hours <br />2.97619e-5 weeks <br />6.849e-6 months <br /> on
February 29, 1992.
Two hours were at rated load and the remainder
was at 900 kW.
The operating logs indicated that operating
parameters stabilized, however this run did not approximate the
conditions of an extended run.
An endurance run was not required by
TS.
The licensee met all TS operability requirements for the EDGs.
Review of maintenance demonstrated that the licensee performs
adequate routine maintenance to maintain the design capability of
the EDGs.
The inspector reviewed the work orders which documented
performance of the last 18 month service inspection of each EDG .
Work orders 3800118417, 3800132112, and 3800118418 documented
10
inspection results for EDGs 1, 2, and 3, respectively.
The inspec-
tions and maintenance accomplished implemented vendor recommenda-
tions and the results met recommended acceptance criteria.
Overall, the inspector concluded that the EDGs were adequately
maintained and TS operability requirements were met.
The
reliability of the EDGs was good at 0.99 and unavailability was
limited to approximately 53 hours6.134259e-4 days <br />0.0147 hours <br />8.763227e-5 weeks <br />2.01665e-5 months <br /> for 1993.
The 1989 load testing
provided assurance of the EDG loading capability.
An endurance test
would provide further assurance of the EDGs accident capability.
5.3
EDG Support Systems
Air Start System
The EDSFA reviewed the air start system design. A finding in this
area identified that the design requirement stated in the UFSAR
regarding the three start capability of the system had not been
adequately verified. The testing previously performed did not
initiate the test from the air receiver 165 psi low pressure alarm
point.
In response to the finding the licensee performed an
appropriate test on the EDG 2 air start system and verified this
design requirement. Similar testing was scheduled for the next unit
1 refueling outage to verify the requirement on EDGs 1 and 3.
The
inspector noted that the licensee did not directly monitor air start
system air quality, however adequate routine start up testing of the
EDGs would identify a degrading system capability.
Fuel Oil System Capacity
The inspector reviewed the fuel oil storage calculations and the
scope of the licensee's review in this area. Calculations 01039.34-
10-M-3, EDG Base and Day Tank 3 Hour Usable Fuel Oil Supply,
revision O, and 01039.3410-M-2, Underground Fuel Oil Storage Tank 7-
Day Useable Fuel Oil Supply, revision 0, demonstrated that adequate
fuel oil capacity existed to meet design and TS requirements.
The
EDSFA identified that the TS minimum day tank level requirement of
290 gallons did not meet the UFSAR design statement of a minimum 3
hour capacity.
The licensee's corrective action was to initiate a
TS change to require a minimum 594 gallons requirement which was the
3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> volume.
The inspector concluded that the fuel oil system met
system design and functional requirements and the findings were
appropriately identified and resolved.
Fuel Oil Chemistry Monitoring
The inspector reviewed the licensee's program for monitoring of fuel
oil quality and identified a weakness in this area.
The licensee
had a history of fuel oil quality concerns.
Biological fouling was
identified in 1989 after which the tanks were cleaned and a biocide
was added to the oil. A particulate problem was identified in 1991
as a result of frequent EDG fuel filter changes.
As a corrective
11
action the onsite fuel oil was cleaned with a portable filtration
system and the fuel oil vendor was changed.
The new vendor provided
a consistently higher grade of fuel oil. Additionally, in 1992, the
licensee added particulate analysis to the chemistry parameters
which were.monitored.
The program weakness was that the licensee
provided no limiting specification for this parameter. A "typical
value" of 10 mg/1 was referenced in the chemistry manual monitoring
program, Nuclear Plant Chemistry Manual, section 52.10.
The EPRI
guide in this subject area, Electrical Power Research Institute
Guide for Nuclear Power Plant Maintenance, Storage and Handling of
Fuel Oil for Standby*Oiesel Generator Systems, August 1988,
recommended a maximum value for this parameter of 10 mg/1.
The inspector reviewed fuel chemistry analysis results for 1992 and
1993. These results demonstrated that the particulate content of
the oil in the above ground storage tank and one of the underground
tanks exceeded the "typical value" in the first quarter of 1993.
No
action was taken to re-sample the tanks until the next routine
sample in the following quarter. The second quarter sample analysis
indicated values were below the "typical value" of 10 mg/1.
Based
on the previous history of fuel quality problems at Surry, this lack
of response to an indication of fuel quality problems was considered
a weakness which was attributable to the lack of a limiting
specification for this parameter *
Heating Ventilation and Air Conditioning (HVAC)
The inspector reviewed the EDSFA HVAC scope, corrective actions for
findings, and available calculations which demonstrated the adequacy
of the HVAC systems' design. The control room and safety related
switchgear room calculation was completed and verified that HVAC
system design ensured that equipment ambient temperature specifica-
tions were not exceeded. This calculation was 02071.2110-M-2,
Control Room Envelope Heat Load.
The HVAC calculations for other
safety related equipment spaces had not been developed. This was an
EDSFA finding.
The inspector verified that these calculations were
being developed as corrective action for this finding.
The
scheduled completion date for the calculations was December, 1993.
The inspector reviewed test and design information to verify that no
operability concerns existed. Operating logs demonstrated that
ambient temperatures for the EOG room with the EOG at rated load
during summer operation stabilized at 89 degrees F.
The logs were
dated July 17, 1992. Site meteorological information indicated that
anticipated site maximum outside temperature was 93 degrees F,
Based on this information it was improbable that EOG room tempera-
tures would exceed the 120 degree F equipment rating. The charging
pump room was
assumed to be the most limiting safety related pump
room because it had the largest pump, 600 horse-power, _and lowest
12
ventilation flow, 7000 cubic feet per minute.
Historical
temperature data for this space demonstrated that ambient
temperatures did not exceed equipment specifications.
Overall, HVAC for safety related equipment spaces was adequately ad-
dressed by the EDSFA.
Findings were appropriately identified and
addressed.
Identified problems were related to a lack of documenta-
tion to verify system capacity.
No apparent operability concerns
were identified.
Seismic Issues
The inspector reviewed the EDSFA scope and assessment of the EDS
seismic applications. The licensee identified examples of unquali-
fied seismic category 2 over qualified category 1 equipment in the
EDG rooms.
These included the steam piping and heaters for space
heating, and overhead lights. The licensee evaluated the piping and
heaters using Seismic Qualification Utility Group (SQUG) criteria
and determined this equipment was adequate to sustain anticipated
seismic stress. Calculation SEQ-1278, EPL Lighting Evaluation dated
November 17, 1992 was developed to assess the lighting. A minor
modification installing additional lighting fixture supports was
accomplished with Engineering Work Request EWR 89-373.
The air start system air receiver pressure switch and connecting
tubing were identified as not seismically qualified.
This tubing
connected into the seismically qualified portion of the system
upstream of the air compressor/receiver check valve.
The tubing was
evaluated and portions upgraded to meet the seismic criteria of the
plant piping standard 831.1.
The tubing which could not be fully
qualified was upgraded with supports to increase seismic capability
and permanent modifications were scheduled under EWR 89-762.
The inspector concluded that the EDSFA accomplished a sufficiently
rigorous review of EDS seismic applications.
Identified findings
were appropriately addressed.
6.
Exit Meeting
The inspection scope and results were summarized on August 20, 1993, with
those persons indicated in paragraph 1.
The inspectors described those
areas inspected.
Proprietary information is not contained in this
report. Dissenting comments were not received from the licensee .
13
7.
Acronyms and Abbreviations
A
- Amperes
ASDOP - Auxiliary System Design Optimization Program
CSA
- Channel Statistical Analysis
- Corporate Nuclear Safety
CUP
- Calculation Upgrade Program
- Design Basis Documents
- Direct Current
EOG
EDS
- Electrical Distribution System
EDSFA - Electrical Distribution System Functional Assessment
EDSFI
Electrical Distribution System Functional Inspection
- Electrical Power Research Institute
- Engineering Work Request
GDC
- General Design Criteria
- Heating Ventilation and Air Conditioning
kV
- Kilovolts
kW
- Kilowatts
- Motor Control Center
mg\\l
- milligrams per liter
- Seismic Qualification Utility Group
SSTX
- Station Service Transformer
- Stone and Webster Engineering Corporation
TS
- Technical Specification
UFSAR - Updated Final Safety Analysis Report
V
- Volts
VDC
- Volts Direct Current