ML20236H408
| ML20236H408 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 06/15/1998 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML20236H370 | List: |
| References | |
| 50-424-98-04, 50-424-98-4, 50-425-98-04, 50-425-98-4, NUDOCS 9807070201 | |
| Download: ML20236H408 (15) | |
See also: IR 05000424/1998004
Text
- _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ - _
.-
e
U. S. NUCLEAR REGULATORY COMMISSION (NRC)
REGION II
Docket Nos. 50-424 and 50-425
tr License Nos. NPF-68 and NPF-81
Report No: 50-424/98-04, 50-425/98-04
Licensee: Southern Nuclear Operating Company, Inc.
Facility: Vogtle Electric Generating Plant (VEGP) Units 1 and 2
- Location: 7821 River Road
Waynesboro. GA 30830
Dates: April '19,1998 through May 16, 1998
Inspectors: J, Zeiler.' Senior Resident Inspector
M. Widmann. Resident Inspector
K. 0'Donohue. Resident Inspector
- . Approved by: P. Skinner. Chief
Reactor Projects Branch 2
'--
Division of. Reactor Projects
,
t >
I
L.
1:
L
Enclosure 2
~
~ 9907070201 990615
PDR ADOCK 05000424
e PDR k.
,
/
- _ _ _ - - _ - _ _ _ _ _ _ _ _ _ _ _ - _
..
.
EXECUTIVE SUMMARY
t Electric Generating Plant Units 1 and 2
NRC Inspection Report 50-424/98-04, 50-425/98-04 l
1
This integrated inspection included aspects of licensee operations, i
engineering, maintenance, and plant support. The report covers a 4-week
period of resident inspection.
Ooerations
e Licensee operators did not fully understand the intent of opening the
three letdown orifice isolation valves when the plant was in ,a water
solid condition during heatup from refueling outage 2R6. A violation
was identified for failure to follow procedures as a result of operating
in this condition without all of the valves in the required open
position (Section 01.1).
- The operators properly responded to a Unit 2 automatic reactor trip that
occurred as a result of a lightning strike to the 500 kilovolt
transmission lines. Plant recovery actions were comprehensive and
restart activities were well controlled and coordinated (Section 01.2).
I
'
.- Operations personnel did not understand the significance of the ~ caution
tags-on the turbine control panel that rendered the turbine trip
function inoperable at the time Mode 2 was entered (Section 03.1).
- - Personnel failed to properly maintain control of materials inside the
- s)ent fuel pool Zone 11 foreign material exclusion (FME) area, in that. l
tiey failed to properly log-equi) ment that entered and exited the zone.
A violation was identified for tais failure to follow FME procedure
requirements (Section 03.2).
.* Operations personnel performance during EDG surveillance testing
represented a weakness in the licensee's planning and preparation prior
to commencement of the surveillance activity (Section 041).
Maintenance l
!
- The licensee's initial response to the identification of errors in the i
Emergency Core Cooling System (ECCS) accumulator level indications were
'
appropriate. Calibration procedures were. revised and compensatory 1
L sctions were taken (Section M1.2). l
1
L
l-
T
1
Enclosure 2 {
.
_ _ _ _ _ _ _ _ _ _ _ _ _ _ - - _ _ - _ _ _ _ = - _ _ _ _ _ . _ _ _ _ - . _- _ _ _ _ _ - - . _- _ .____-_________-
n_______
.
.
2
Enaineerina
e The identification by a Plant Equipment Operator of a degraded condition
associated with the Unit 1 Train B Se
example of good attention to detail. quencer step driver
Engineering.and card was an
Instrumentation
and Control personnel support in addressing the degradation was
aggressive and timely. A temporary modification implemented to restore
the sequencer to operation was properly prepared and reviewed (Section
E1.1).
,
!
!
!
Enclosure 2
r
l
l
t_ _
- _ _ _ _ _ - _ - _ - _ _ _ _ _ _ _ _ _ _ _ _ -
!- ,
.
, .
Reoort Details
-
Summary of Plant Status
! Unit 1
The unit operated at full power throughout the entire inspection period.
' Unit 2-
' The unit began the inspection period in Mode 3 following the completion of the
sixth refueling outage -(2R6). Reactor startup commenced April 18. 1998 and
full' power operation was attained on April 24. On May 8 -an automatic reactor trip occurred from 100 percent power due to a lightning strike on the offsite
= power transmission line. Following troubleshooting and corrective actions,
- reactor startup was initiated on May 9. The. unit was returned to Mode 3'that
, same day in order to perform additional turbine generator testing for the
'
' lightning strike. Following this testing, reactor startup recommenced on
May 12. Full power operation was attained on May 15. The unit operated at
essentially full. power the remainder of the-inspection period.
J. Operations
01- . Conduct of Operations
01.1 Closed Letdown Orifice Isolation Valve durina Solid Plant Ooeration
a. Insoection Scooe (71707)
The inspectors observed and reviewed the licensee performance and
implementation of the Unit 2 heatup activities per Procedure 12001-C,
" Unit Heatup To Hot Shutdown (Mode 5 to Mode 4)." Ruision (Rev.) 38.
.
b) Observations and Findinas
On April 16, 1998, during a review of com)leted portions of Procedure
12001eC, the inspectors identified that tie licensee had failed to
complete a step for ensuring that all three letdown orifice isolation
. valves remained open while the unit was in solid plant- operation.
On April 15, while preparing to enter solid plant operation, operations
personnel were unable to open one of the three letdown orifice isolation
, valves as recuired by step A4.2.3.b of procedure 12001-C. A maintenance
work order.(FWO) was written to investigate and repair the valve
problem. -The Unit Shift Supervisor (USS) placed an asterisk by the step
and entered a note that isolation valve 2HV 8149B could not be opened
and that a MWO had been initiated. -The USS decided to enter solid plant
operation with the valve closed. On April 17, the valve was repaired,
opened. and the procedure step was signed off as complete. Solid plant
,
operation was exited on April 18.
'
Enclosure 2
- ].
_ _ _ _ - _ _ .
..
1 .
.
2
The inspectors reviewed the Updated Final Safety Analysis Report (UFSAR)
l and Westinghouse " Precautions. Limitations and Setpoints (PLS) for-
l Nuclear Steam Supply Systems." Both the UFSAR and PLS indicated that
l all three isolation valves should be open wnen the plant is in a water
solid condition. The basis for the valves being open is to provide a
letdown flowpath if the Residual Heat Removal system should
' inadvertently be isolated. A letdown flowpath provides additional
protection during an overpressure Reactor Coolant System (RCS)
. transient. limiting the potential challenge to the pressurizer code
safety valves. During a transient, if the cold overpressure protection
system (COMS) operates properly, an excessive high pressure condition
would not be reached. The letdown flow will aid COMS to perform its
function.
, The inspectors reviewed Administrative Procedure 00054-C. Rules for
Performing Procedures. Rev. 11, which provides guidance for procedure
use and adherence. This procedure allows the USS to perform steps out
of sequence as long as it does not violate the intent of the procedure,
create an unsafe plant condition, or result in omission of required
work. Discussion with the USS indicated that he did not consider this
action to be a change in the intent of the procedure. The inspectors
discussed with licensee management that the USS made the decision to
continue with solid plant operation without fully understanding the
intent of having all three isolation valves open. Additionally.. the
decision was made without thoroughly evaluating the impact of the change 1
in normal solid plant operation or soliciting guidance from engineering '
or management personnel. The inspectors concluded that the decision to
continue with solid plant conditions without ensuring that 2HV-8149B was
open, was not allowed by procedure 00054-C. in that, the deviation
involved omission cf required work and violated the intent of procedure
12001-C.
The inspectors determined that the safety significance of the closed l
isolation valve was minimal. Had there been an inadvertent isolation of i
the RHR system, the two other letdown isolation valves were open which
would have provided a letdown flowpath. Additionally, the COMS remained
operable during the period.
As a result of this issue, the licensee plans to revise unit operating
procedure 12001-C to require that all three letdown orifices' 1 solation
valves must be open prior to continuing with solid plant operations. In
addition, the licensee plans additional training on procedure adherence.
The failure to open the letdown orifice valve while operating in solid
plant conditions did not meet procedure requirements of 12001-C. nor the
,
guidance for deviating from procedures as prescribed by procedure
l 00054-C. This is identified as Violation 50-425/98-04-01. " Failure to
[ Follcw Procedures for Letdown Orifice Isolation Valve Configuration in
j Solid Plant Operations."
tinclosure 2
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
..
-
.
i
3
c; Conclusions
The inspectors concluded that the licensee did not fully understand the
- intent of-opening the three letdown orifice isolation valves when the
plant was water solid nor was there a thorough evaluation performed for
the impact of closing one of the isolation valves prior to entering
-water solid conditions. This was identified as a violation .for failure
ito follow procedures.
01.2 -Unit 2 Reactor Trio Due to Liahtnina Strike
P
a; Insoection'Scooe (71707. 93702. 40500)
The inspectors-reviewed the May 8.1998. Unit 2 automatic reactor trip,
including post-trip recovery actions and subsequent startup activities.
-b. Observations-and Findinas.
On May 8. at 4:01 a.m.. an automatic reactor trip occurred on-Unit 2
from.100 percent power as a result of a lightning strike on one of the '
two 500 kilovolt (KV) transmission lines that supply off-site power.
The strike caused an electrical fault of the Phase A Main' Step-Up
-Transformer which resulted in a turbine trip. All rods fully inserted
-
and the unit was safely shutdown to Mode 3. All safety systems
functioned as designed.
The licensee formed a critique team to investigate the cause of the trip
and to identify actions:necessary for- )lant restart. The. lightning
strike caused extensive damage to the 3hase A Main Step-Up Transformer
which necessitated replacement with the' spare transformer. Inspection
and testing was aerformed'on the Phase B-and C Main-Step-Up Transformers
to verify that tiere was no damage. Following completion of the post-
trip review and maintenance restart activities the licensee initiated
plant startup and entered Mode.2 on May 9.
On May 9. following licensee discussions with the turbine / generator
s supplier, additional-concerns were raised regarding the adverse impact
that the lightning' strike could have had on the generator rotor. and
stator windings. As a result of these discussions, licensee management
,
decided.to return the unit..to Mode 3 and perform additional testing.
4
Testing was completed on.May 12 with no adverse conditions being
identified. Following com)letion of this testing. Mode 2 and reactor
criticality was achieved tlat same day.
The inspectors reviewed plant logs and post trip data, discussed the i
event with key-licensee personnel, and walked down plant equipment, i
including maintenance and' testing activities associated with the main
step-up transformers. The inspectors did not identify any concerns
during this-review. !
!
L Enclosure 2
L
,
. - ' '
, >
.
L_ _ .__ _ _ _ _ _ . _ _ _ _ _ _ _ _ _ _ _ . _ _ _ _ _ = _ _ . _ _ _ _ _ _______________________9
- .. _ _ _ _ _ - - - _ - _ - _ _ _ - _ _ _ _ - _ - _ _ - - _ - _ -
L' '
-,;.
,
v.
4
.-- . . .
At the conclusion of the. report period, the licensee's event critique
-review team was still evaluating the root cause of the transformer
failure and.whether the-lightning protection system associated with the
[ > transmission line and transformer functioned properly.
c. -Conclusions
The inspectors concluded that operator response.to the reactor trip was
appropriate. Plant recovery actions were comprehensive and restart
L . activities were well controlled and coordinat'ed.
03! Operations Procedures'and Documentation
> 03.1 Turbine Trio Function Inocerable durina Mode 2 Entry
,
a. Insoection Scoce (71707)
l ,
- The inspectors reviewed the licensee's identification that the turbine
, trip. function was inoperable during startup from refueling outage .2R6.
l -
.
.b. -Observations and Findinas
On April 19. at 3:00 a.m.L. Unit 2 entered Mode 2.- At approximately
l 4:30 a.m <. operations personnel . identified that caution tags on the
L . turbine control panel addressed two open links which made the turbine
L trip from a reactor trip function inoperable.- The links.were closed
,
- which restored the turbine trip function.
The inspectors determined that on April 18. during day shift, the Unit 2
L USS had authorized a jumper to be placed in the main turbine circuitry
per MWO 29702068. The jumper allowed two links in the turbine control
, Janel to be opened causing the turbine trip on reactor-trip circuit to-
!
, Je ' inoperable. Two caution tags identifying the plant condition were
L 4
'placed on the control room board at the main turbine control panel,
n After the MWO~was completed, the jumper was left'in place to allow for-
P + turbine shell warming with the reactor trip breakers oyen. Operations
L
'
personnel failed to remove the clearance and restore t1e turbine trip
function following turbine shell warming and prior to Mode 2 entry. 1
i
The inspectors determined that caution tags were not required to be I
reviewed as part of the startup procedure for Mode 2: however, the l
procedure does require review of the limiting condition of operation
p.
'
log. Since.a mode change was imminent, this configuration met the
conditions-for an "information only"' limiting condition of operation !
(Info LCO)?to be prepared and logged in the LCO tracking lcg.
c, Operations failed to enter an Info LC0 when the' links were opened.
tt
The . inspectors reviewed Technical Specification (TS) Table 3.3.2-1 for
the engineered safety features actuation system instrumentation
requirements. The turbine trip and feedwater isolation function
l
Enclosure 2
L'
s
w__-_____ _ _ _ _ _ _ _ _ ._
.
,
. _ . _ - _ - - _ _ _ _ _ - - - _ _ _ _ _ -----_
! -:
.
4
5
required'the circuitry to be operable in Modes 1 and 2. However. a note-
associated with Mode 2 allows the function.to be inoperable.as-long as
the main feedwater' isolation and regulation valves and their associated
- .
bypass. valves are closed and deactivated, or the-feedwater line is
-isolated by a closed manual. valve. The inspectors determined that these
conditions were not. met when the unit entered Mode 2.
! The Bases-for TS 3.3.2 stated the following: " Turbine trip and feedwater-
'
isolation functions _must be operable in Modes 1 and 2 except when one
main feedwater isolation or regulation valve and associated bypass valve
per.feedwater line are closed and deactivated or isolated by a closed
manual-valve when the main feedwater system is in operation and the
turbine generator. may be in operation." The licensee considered that
E
the bases limited the Mode 2 applicability of the turbine trip and
.feedwater isolation function.to when the feedwater and turbine generator
systems were in operation. Since the feedwater and turbine generators
- # systems were not in service between 3
- 00 a.m. and 4:30 a.m. on April 18.
,
'
1998. the licensee believed that the plant had not operated outside of
.TS' requi rements .
The inspectors determined that further review of this interpretation was
L .necessary. This istidentified as Unresolved Item (URI) 50-425/98-04-02,
L " Complete Review of. Turbine Trip Inoperability in Mode 2.~.pending'
additional NRC review.
c; ' Conclusions:
1The inspectors concluded that operations aersonnel'did not understand
,f the significance of the caution tags on t1e turbine control panel at the
time Mode 2 was entered. A URI was identified to further review the
licensee's position regarding interpretation of the <TS mode
L . applicability for the turbine trip function.
03.2 Foreian Material Exclusion Control Discrepancies
a. Insoection Scooe (71707)
p i
.During routine
-Exclusion-(FME)controls plant walkdowns,
at the Unitthe inspectors reviewed
fuel Foreign pools, Material
,
1 and Unit 2 spent
b. Observations and Findinos
On April 28. 1998, the inspectors identified various material inside the
Zone II area that was.not logged in accordance with the requirements of
,
' Procedure 00254-C. " Foreign Material Exclusion and Plant Housekeeping
L ' Programs. " Rev. 18. Procedure 00254-C stated that tools, eq. .nent, and
I' material entering and leaving a zoile are to.be accounted for via logging
- on the FME inventory form. ~ Based on review of the log sheets stationed
e
~~ 'a at the Unit 1 and Unit 2 spent fuel pools, the inspectors identified
that eight items inside the Zone II area, were not accounted for on the
Enclosure 2
l
l
i>
.
4 - _ _ _ , _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . _ _ _ _ , _ _ _ , _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . , _ _ _ . _ _ _ _ _
o
'
..
>
.
.
6
y log sheets. In addition, the inspectors identified one item, a
' radiation detector, that was listed on the log sheet as being brought
into the Zone.II area on April 23. but could not be located within the
zone.
The inspectors discussed these discrepancies with licensee management.
The licensee immediately responded and removed the material from inside
the Zone-II area and verified that the radiation detector listed on the
log was removed the same day it entered the zone. A condition report
<
was generated for..the FME discrepancy' items.
Several. minor FME control discrepancies following refueling outage 2R6
' core off-load were documented in NRC~ Inspection Report 50-424. 425/98-
03.
The inspectors concluded that contrary to the requirements of procedure
00254-C. the licensee had fai. led to properly log all tools, equipment.
and materials that entered and left the Zone II area around the spent
fuel pools. As such, this issue was identified as VIO 50-424. 425/98-
04-03. " Failure.to Maintain FME Controls at Spent Fuel Pools."
~c c. Conclusions
The inspectors concluded that personnel failed to properly maintain
control of materials inside the spent fuel pool- Zone II FME area. A
violation was identified for failing to properly log equipment into and
out of the zone.
04< Operator Knowledge and Performance
04.1 Emeroency Diesel Generator Elevated Cylinder Exhaust Temperatures
e ,
a. Insoection Scooe (71707)
The inspectors observed licensee performance'of Emergency Diesel
Generator (EDG)^ operation procedures, documentation of data in operating
logs, and associated surveillance after the completion of EDG
maintenance activities.
b. Observations and Findinos ;
On April 7 and 9. during the performance of the 2-hour 110% load
3
surveillance test, exhaust temperatures on both the 2A and 2B EDGs
exceeded the criteria specified in Procedure 11885-C. " Diesel Generator
L
>
0)erating Log." Rev. 23.- On April 7. one cylinder on EDG 2B exceeded
t1e criteria during the second hour .of the .110% engine run. On April 9.
-during performance of the EDG 2A run, eight cylinders exceeded the
criteria during the first hour and nine cylinders during the second
hour.
Enclosure 2
!.
I
I
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ - _ - _ _ _ _ _ _ _ _ _
- _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
..
.
7
An exhaust temperature criteria of 1050 F was established in Procedure
11885-C t.o alert operators that the EDG may be o3erating abnormally.
Procedure 11885-C contained a " note" requiring tlat if exhaust
temperatures exceed 1050 F. then operations personnel are to contact the
maintenance department to confirm that inlet temperatures into the
turbocharger are less than 1200 F. In accordance with the procedure if
temperatures are greater than 1200 F. operations personnel are to reduce
load as necessary to bring temperatures within' the criteria established.
However on April 7 and 9. after the 1050"F criteria was exceeded.
maintenance personnel were unable to obtain the necessary temperature
data due to temperature equipment problems. As a result, engineering
judgement was used to justify the magnitude of the high exhaust
temperatures and the continued operation of the EDG. The inspectors
reviewed the completed surveillance data for both EDG 24-hour runs and
noted that exhaust temperatures returned to normal operating ranges
after the 110% portion of the tests were completed.
The inspectors noted that the procedure was recently revised to include
the new exhaust temperature criteria without operations personnel fully
understanding the impact of the " note" and what it would take to support
the temperature measurement activity. Also, no specific training had
been given to aid the operators in understanding or implementing the new
procedure revision and operations personnel were not sensitive to the
action required by the " note" in Procedure 11885-C. As a result action
was not taken to timely contact the maintenance department to initiate
temperature measurement activities, or timely contact the appropriate
engineering personnel for evaluation of the high temperature conditions.
During the April 7 surveillance, operations personnel did not contact
maintenance until approximately six hours into the 24-hour run. After
maintenance realized that the test equipment broke during efforts to
collect data o)erations control room staff contacted system
engineering. T11s call occurred approximately 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> after the 110%
load portion of the surveillance (i.e. 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br /> into the 24-hour run).
In addition, the inspectors noted that operations personnel did not
reduce the load on either EDG run as delineated by the procedure note
until after the 110% loaded runs were completed. Following the 2A EDG
testing, the procedure was not revised to la more specific prior to the
2B EDG testing. The procedure was not revired until after the issue was
l raised by the inspectors during the EDG 2B 24-hour run.
The inspectors determined that the safety significance of this issue was
minimal. in that, no problems were identified for either EDG during or
after performance of the 24-hour surveillance. Since performance of
thesesurveillances,thelicenseehasdevelopedseveraicoursesof
action to address future issues regarding elevated exhaust temperatures.
Some of those actions included: a permanent revision to Procedure
11885-C to evaluate the temperature criteria during 110% loaded runs; a
shift briefing item to address human performance issues regarding
timeliness: a caution being added to the ESFAS test procedures to warn
the operators that temperature criteria could be challenged during the
Enclosure 2
i .--- - - _ - - . - - - - - -. - - - - - - - - _ - - - - - - - - - - - - - - - - _ - - - - - - - _ - - _ - -
. _ __ _ _ _ _ _ _ _ _ - - _ - _ _ - _ _ _ - - - _ - _ _ _ _ _ _ - _ _ _ _ _ _ _ _
.,
~.
8
i 100% load portion of the EDG 24-hour test: and guidance to notify
lz maintenance personnel prior to the performance of the EDG test in order
l to collect temperature data if the criteria is exceeded,
,
c. Conclusions
The inspectors concluded that operations personnel performance during
EDG surveillance testing-represented a weakness in the licensee's
l
'
planning and preparation prior to commencement of the surveillance
activity.
L
11. Maintenance
g
l M1 Conduct of Maintenance
L
M1.1 Maintenance Work Order and Surveillance Observations (62707)
L The inspectors ~ observed portions of the following maintenance and
l surveillance activities.
MWO 19801337 Implement Temporary Modification 98-V1T015
L MWO 29801434- Inspect Phase A Main Ste)-Up Transformer for Damage
! following Lightning Strice
1
14400-1 Control Room Emergency Filtration Actuation Logic
l test, Rev. 17
! 14960;2 Pressurizer Continuous Spray Flow Verification. Rev.1
The observed maintenance and surveillance activities were generally
completed by personnel knowledgeable of their assigned tasks.
Procedures were present at the work location and being followed.
Procedures provided sufficient detail and guidance for the intended
activities. The inspectors concluded that routine maintenance and
surveillance activities were satisfactorily performed.
M1.2 Emeroency Core Coolina System Accumulator level Indication Errors
a. Insoection Scone (61726)
The inspectors reviewed the licensee's identification of errors in the
calibration of the emergency core cooling system-(ECCS) accumulators on -
both units.
t
L Enclosure 2
_ _ _ _ _ - _ - _ _ _ _ _ _ _ _ _ _ _ _ _ -
_ _ _ _ _ - __ _ _ _
.. l
.
9
b. Observations and Findinas
April 20,1998. the licensee notified the NFC + hat instrumentation and
controls personnel discovered an error in the c @ nrotion for the level
instrumentation for all four ECCS accumulators on each unit. The error
was such that it was possible for the actual accumulator levels to be
outside TS requirements.
After identification of the calibration error, the accumulator levels
were immediately verified, including allowance for the calculated
errors. to be within the required TS volume. The error was quantified 4
to result in anywhere from 15% higher than actual indicated level to 5%
lower than actual. TS 3.5.1 requires accumulator level to be maintained
with a volume of borated water E 6555 gallons and 5 6909 gallons.
Operator compensatory actions were implemented to ensure compliance with {
TS level requirements by monitoring level within a range of 50% to 60% .
as indicatec on the control room level gauges. ,
I
Accumulator level is measured using a differential pressure (D/P) l
bellows transmitter with high side and low side sensors. The error i
originated from the erroneous use of the transmitter calculated D/P
rather than the pressure required at the input sensor to achieve the
voltage output expected for a saecific accumulator level. This error )
was introduced in 1990 during t1e original calibration procedure
development. The licensee corrected the calculations and revised the
calibration procedures. Recalibration of accumulator level
instrumentation on both units was completed May 6.1998. 3
The licensee determined that the calibration errors identified on April
20 did not result in operating outside the design basis of the plant. l
The basis for this position was the determination that there was
sufficient water volume in the accumulator lines to compensate for the
calculated water volume caused by the error. The water in the 'I
accumulator lines was not included in the Large Break Loss of Coolant i
Accident analysis; but, could be used to offset the water volume from
the calibration error. At the end of the report period, the licensee )
was still reviewing actual accumulator level historical data to
determine whether there had been a s)ecific instance where the TS level I
requirements were not met based on t1e associated error. In addition. I
the licensee had not completed a broadness review plan to evaluate l
whether similar errors could exist in other level control systems.
Pending com)1etion of these items by the licensee and subsecluent NRC
review of t1e findings, this issue is identified as URI 50-424. 425/98- )
04-04. " Complete Review of ECCS Accumulator Level Error Issue."
'
1
Enclosure 2
i i
__. _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ -
- - _ - _ _ _ - _ _ - _ - _ _ - _ - - _ - - _. _ _ _ _ - _ _ _ ._ ..
..
..,
!
l
.
1
l
L , 10
c .' Conclusions
The inspectors concluded that the licensee's' initial response to the
identification of errors in the ECCS Accumulator level indications was i
appropriate. Calibration procedures were revised and compensatory {
L actions were taken. A URI was identified pending further review of the i
safety impact of the level error and the licensee's evaluation of the
potential for errors in similar. level control systems.
III. Enoineerino I
'
El' Conduct of Engineering l
I
E1.1 Unit 1 Secuencer Malfunction
a. Insoection Scooe (37551)
The inspectors reviewed the May 3.1998, malfunction of the Unit 1 Train 1
B. Sequencer.
]
'b. Observations and Findinas
On May 3. a plant equi) ment operator (PEO) identified flashing
indicating lights on t1e Unit 1 Train B sequencer panel. The lights
were unexpected, and upon investigation it was determined that the
flashing was caused by a component failure on a sequencer driver step
card. . As a result of the failure ~ the automatic sequencer steps for
loading the Train B Containment Spray Pump (CSP) were not~ functional.
- In this condition, there was a potential for the B CSP to be loaded on
the first sequencer step as opposed to the fifth. ' The licensee i
. determined that this could lead to overloading the sequencer and '
potentially challenging the performance of the sequencer and therefore
the availability of the Train B emergency components in the event of a
,
safety. injection actuation. j
Operations removed the B CSP from service and developed a temporary
modification to resolve the sequencer problem by bypassing the l
malfunction condition on the driver step card until permanent repairs
'
could be performed. The ins)ectors reviewed temporary modification 98-
V1T015.- It was determined t1at the temporary modification package was
arepared in accordance with the licensee *s procedure.00307-C. " Temporary i
modifications." Rev.16. The inspectors also noted that a 10 CFR 50.59 '
evaluation was completed and included in the' package. The temporary
' modification was installed on May 4,1998.
L
i
i
Enclosure 2 !
__ _ _ - _ _ - _ _ _ _ _ . ____ ___ . _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __
..
.
I
11
l c. Conclusion _1
The identification by a Plant Equipment Operator of a degraded condition
l associated with the Unit 1 Train B Sequencer step driver card was an
l example of good attention to detail. Engineering and Instrumentation
and Control personnel support in addressing the degradation was
aggressive and timely. A temporary modification implemented to restore
the sequencer to operation was properly prepared and reviewed.
IV. Plant Suoport
R1 Radiological Protection and Chemistry Controls
R1.1 General Comments (71750)
The inspectors periodically toured the Radiological Control Area during
the inspection period. The inspectors concluded that rad. tion control
practices observed were proper.
S1 Conduct of Security and Safeguards Activities
S1.1 General Comments (71750)
The inspectors periodically toured the protected area. noting that the
perimeter fence was intact isolation zones were maintained on both
sides of the barrier and free of objects. The inspectors periodically
observed personnel, packages, and vehicles entering the protected area
and verified that necessary searches, visitor escorting, and s)ecial
purpose detectors were used as applicable prior to entry. Lig1 ting of
the perimeter and of the protected area was acceptable.
V. Manaaement Meetinas and Other Areas
X Review of Updated Final Safety Analysis Report
While performing the inspections discussed in this report, the
inspectors reviewed the applicable portions of the UFSAR that related to
the areas inspected. The inspectors verified that the UFSAR wording was
consistent with the observed plant practices procedures and/or
parameters unless otherwise identified in this report.
X1 Exit Meeting Summary
The inspectors ) resented the inspection results to members of licensee
management at tie conclusion of the inspection on May 20. 1998 The
licensee acknowledged the findings presented.
Enclosure 2
__ _ _ _ _ _ _
..
.
12
PARTIAL LIST OF PERSONS CONTACTED
l Licensee
J. Beasley, Nuclear Plant General M6 nager 5
S. Chestnut. Manager, Operations
'
G. Fredrick. Plant Support Assistant General Manager
J. Gasser Plant Operations Assistant General Manager
K. Holmes, Manager, Maintenance
M. Sheibani. Nuclear Safety and Compliance Supervisor
C. Tippins, Jr., Nuclear Specialist I
\
INSPECTION PROCEDURES USED
IP 37551: Onsite Engineering
IP 40500: Effectiveness of Licensee Controls in Identifying Resolving. and
Preventing Problems
IP 61726: Surveillance Observation
IP 62707: Maintenance Observation
IP 71707: Plant Operations
IP 71750: Plant Support Activities
IP 93702: Prompt Onsite Response to Events at Operating Power Redctors
ITEMS OPENED AND CLOSED
Ooened
Tvoe Item Number Status Description and Reference
VIO 50-425/98-04-01 Open Failure to Follow Procedures
for Letdown Orifice Isolation
Valve Configuration in Solid
Plant Operations
(Section 01.1)
URI 50-425/98-04-02 Open Complete Review of Turbine
Trip Inoperability in Mode 2
(Section 03.1)
VIO 50-424. 425/98-04-03 Open FME Controls Not Maintained at
Unit 1 and 2 Spent Fuel Pools
(Section 03.2)
URI 50-424, 425/98-04-04 Open Complete Review of ECCS
Accumulator Level Error Issue
(Section M1.2)
Enclosure 2
_