IR 05000483/1993004
| ML20045C074 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 06/14/1993 |
| From: | Jackiw I NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML20045C071 | List: |
| References | |
| 50-483-93-04, 50-483-93-4, NUDOCS 9306220050 | |
| Download: ML20045C074 (10) | |
Text
n
.
U. S. NUCLEAR REGULATORY COMMISSION
REGION III
Report No.
50-483/93004(DRP)
l Docket No.
50-483 License No.
NPF-30 Licensee: Union Electric Company Post Office Box 149 - Mail Code 400 St. Louis, M0 63166 Facility Name:
Callaway Plant, Unit 1 Inspection at:
Callaway Site, Steedman, M0
+
Inspection Conducted: April 9 through May 31, 1993 Inspectors:
B. L. Bartlett D. R. Calhoun
.'
I. N. Jackiw
,
J. A. Gavula b
Approved By:
_
I. N.,Jackiw, Date
Reactor Projec,fhief,
ts, Section 3A
,
Inspection Summary Inspection from April 9 throuch May 31. 1993 (Report No. 50-483/93004(DRP))
Areas Inspected: Routine unannounced safety inspections of onsite followup of events, operational safety verification, and maintenance / surveillance was
-
conducted.
Results: Of the areas inspected no violations were identified.
A summary follows.
Plant Operations Control room operations continued to be conducted in a professional and safety-focused manner. On April 28, 1993, the owl shift crew promptly responded to a loss of service air.
i One performance weakness and another concern identified during the 1992 annual
-
exercise were repeated during the licensee's second practice drill on May 19, 1993.
These were inadequate contamination control as _well as excessive i
involvement by a controller.
9306220050 930614 PDR. ADOCK 05000483 G
PDR j
.
"
Radioloaical Controls The licensee's performance in the area of radiological controls was at a satisfactory level during this reporting period.
Maintenance and Surveillance The licensee generally performed maintenance and surveillance activities in_ a controlled manner, however, during troubleshooting activities, equipment was manipulated without informing the control room staff.
The control room temperature had been trending up due to the control room air conditioning unit tripping off. Upon discovery, the system engineer locally reset the unit, but the unit did not restart. At that time, indication was received in the control room and the reactor operator restarted the unit.
Engineerina and Technical Sucoort Good engineering support was provided during repair and troubleshooting activities on the 'A' train load shedding and emergency load sequencing.
'
Identification, by quality assurance, of-the licensee's failure to have a qualified procedure to perform charcoal tray refills was a good finding.
The lack of a mechanism to assure the instrument and control spreadsheet, used to perform calibration of safety-related radiation monitors, was adequately
,
maintained and properly updated when necessary indicates a. program weakness.
Manaaement Involvement Management continued to periodically observe and followup on issues which surfaced during field activities.
The plant manager observed repair efforts on the load shedding emergency load sequencer.
i l
l
.
.
!
DETAILS
'
1.
Persons Contacted D. F. Schnell, Senior Vice President, Nuclear
- G. L. Randolph, Vice President, Nuclear Operations W. R. Campbell, Manager, Callaway Plant
- C. D. Naslund, Manager, Nuclear Engineering
,
- J. V. Laux, Manager, Quality Assurance J. D. Blosser, Manager, Operations Support
- M. E. Taylor, Assistant Manager, Work Control D. E. Young, Superintendent, Operations M. S. Evans, Superintendent, Health Physics S. S. Sampson, Supervising Engineer, Site Licensing
- J. R. Peevy, Assistant Manager Operations and Maintenance G. R. Pendegraff, Superintendent, Security
- A. C. Passwater, Manager, Licensing and Fuels G. A. Hughes, Supervisor, Independent Safety Engineer Group C. S. Petzel, Quality Assurance Engineer J. A. McGraw, Superintendent, System Engineering R. D. Affolter, Superintendent, Design Control
- J. L. Cameron, NRC Inspector
- Denotes those present at one or more exit interviews.
In addition, a number of equipment operators, reactor operators, senior reactor operators, and 'other members of the quality control, operations, maintenance, health physics, and engineering staffs were contacted.
2.
Onsite Followuo of Events (93702)
On April 28, 1993, the licensee experienced a loss of the operating service air compressor. Due to check valves failing to seat, the service air system pressure dropped. This condition resulted in the isolation of the chemical and volume control system (CVCS) letdown flow.
,
The control room staff properly responded to the incident.
- At approximately 2:15 a.m., the 'C' air compressor tripped.
The other-two compressors immediately loaded in an attempt to restore system air pressure.
In addition, the control room dispatched an equipment operator (E0) to restart the 'C' air compressor. The E0 manually
isolated the air compressor after realizing that the system was
depressurizing by air backflowing out the suction of the _'C' compressor.
This backflow condition prevented the other two air compressors from
,
maintaining normal system pressure of 120 pounds per squre inch.
Consequently, CVCS letdown flow was isolated when air-operated valves BG
HV-8149C and BG LCV-0060 failed closed on low air pressure.
Shortly thereafter, the 'A'
and 'B' air compressors re-established normal system air pressure and CVCS letdown flow was restored.
.
'
Subsequent investigation by plant personnel determined that the
discharge check valves, one internal to the compressor and the other external, had failed.
Unseating of these check valves eventually caused the compressor to overheat and trip.
The internal check valve was a poppet type spring close valve which failed due to normal wear; the other valve was a swing arm check valve which failed to reseat.
The licensee later replaced the valves and restored the 'C' air compressor i
to service.
Initially, both valves will be inspected annually to
,
monitor for signs of degradation; the continuation of the annual
'
inspections will be determined by valve condition during initial inspection.
In addition, verification, of component reliability was made, for the corresponding valves on the 'A'
and 'B' air compressors.
Conclusions i
The loss of instrument service air was properly responded to by the
'
.
onshift crew.
No violations or deviations were identified.
3.
Plant Operations (71707)
The objectives of this inspection were to ensure that the facility was being operated safely and in conformance with license and regulatory requirements and that the licensee's management control systems were effectively discharging the licensee's responsibilities for continued safe operation.
The methods used to perform this inspection included direct observation of activities and equipment, tours of the facility, interviews and discussions with licensee personnel, independent verification of safety system status and limiting conditions for operation, corrective actions, and review of facility records.
Areas reviewed during this inspection included, but were not limited to, control room activities, routine surveillances, engineered safety feature operability, radiation protection controls, fire protection, security, plant cleanliness, instrumentation and alarms, deficiency reports, and corrective actions.
The inspectors observed various aspects of the licensee's second pre-exercise drill which was conducted on May 19, 1993. Overall, the licensee's performance was acceptable; however, a performance weaknesses and another concern identified during NRC's evaluation of the 1992 annual exercise were repeated in the May 1993 drill.
Excessive participation on the part of a controller was observed at health physics (HP) access. The controller was with a repair team who had exited the radiological control area. When the team was questioned about repair status, the controller provided the majority of the information. A lack of contamination control was demonstrated by one of the field monitoring teams. The HP technician did not don gloves while counting a sample.
The technician assumed the use of tweezers was sufficient. Also, the team inadvertently drove out of the plume with the back window down.
Vehicle windows should be up when crossing through the plume.
Quality
-.
.
.
- -
-.
_-
-
..
-
-.
-
-
..
- c
assurance staff, who also observed the' drill, noted these and several other performance problems.
>
'
Conclusions Routine plants operations-were properly. conducted by the various operating crews.
Findings identified during the 1992 exercise were
,
repeated during the licensee's practice drill.
j No violations or deviations were identified.
i 4.
Maintenance / Surveillance (62703) (61726)
Ti l
Selected portions of the plant surveillance, test, and maintenance activities on safety-related systems and components were observed or
,
reviewed to ascertain that..the activities were. performed in accordance with approved procedures, regulatory guides, industry codes and
'
standards, and the technical specifications (TS).
The following. items i
were considered during these inspections:
the limiting conditions for
!
-
operation were met while components or systems were removed from i
service; approvals were obtained prior to initiating the work;
'
activities were accomplished using approved procedures and were inspected as applicable; functional testing and/or calibration was
>
performed prior to returning the compenents or-systems to service; parts
,
'
and materials that were used were properly certified; and appropriate fire prevention, radiological, and housekeeping conditions.were
.
maintained.
]
a.
' Maintenance
)
The reviewed maintenance activities included:
Work Reouest No.
Activity W157030 Replaced damper operator, GDTZ00 llc, essential service water pump room supply
fan 'B' air exhaust' damper.
,
W153911 Repaired low ~ vacuum on containment purge
-
exhaust radiation monitor, GT-RE-0022.
,
W530721 Local leak rate test of containment
'
emergency hatch shaft seals.
W152469 Replaced charcoal trays and test canisters in the 'B' control room filtration and'
-
,
adsorber unit.
W157168 Replaced transducer and power. supply for
'I channel.three, in ' A' train load shedding and emergency load sequencing cabinet.
j t
.
,
. -.
e
,
-.-..
.
_
_ _ _ -
_
._-
_
__
,
L.
H G531221-047 Adjustment of the limit switch actuating
rod for the main steam loop three steam L
supply to the TDAFW pump valve, AB HV0049.
i G527239-004 Changeout of the 'B' chemical and volume
'
control system seal water injection i
filter.
.
R100648B Performed vibration analysis of the ' A'
spent fuel pool cooling water pump.
Good trending of test data resulted in the licensee replacing degraded components in the 'A' train load shedding and emergency load sequencing (LSELS), prior to their failure.
In addition, one wrong size fuse was identified and replaced.
Trending data of surveillance test results indicated that the'
,
l transdacer and the power supply for the channel three undervoltage
';
function showed signs of degradation. After replacement of these components, the power supply fuse for the automatic test insertion (ATI) panel failed.
In the process of procuring a new fuse, it was discovered that the installed fuse was a MDL 125V, 2 amp.,
however, in accordance with the vendor's manual, the fuse should have been a type 3AG, 250V, 2 amp.
'
l The installation of the incorrect fuse did not adversely affect
'
the operability of the system.
The required input voltage (48VDC)
of the ATI system was below the 125V rating of the incorrect fuse.
In addition, the instrumentation and control technicians, as well
,
as the system engineer (SE), verified system operability' prior to l
performing any maintenance activities. As well as the above components being replaced, the ATI power supplies (15VDC and i
30VDC) also were replaced after failing during subsequent troubleshooting activities. The 'A' train LSELS was restored to service upon satisfactory completion of surveillance testing.
During this maintenance activity, which transpired over two shifts, the demand on the system engineer's time to perform briefings could have been more organized, constructive, and less interruptive to the completion of the work activity.
As opposed to conducting one briefing for the entire oncoming crew, the i
system engineer performed a number of individual briefings to
!
various control room staff members.
As a result, the repair activities were interrupted on several occasions so that the SE could conduct briefings.
Even though this did not significantly l
extend the time the licensee was in the TS action statement, work l
would have progressed more smoothly had the SE been allowed to
.
I provide a repair status at one time to all pertinent-control room I
l personnel.
!
'
6 l-l-
L L
l
..
b.
Surveillance
'The reviewed surveillances included:
1 Procedure No.
Activity i
ISL-GT-00R32 Loop calibration of containment atmosphere radiation detector.
ISL-BB-0T421 Calibration of loop 2 delta temperature / temperature average.
OSP-AL-P0002 Section XI turbine driven auxiliary feedwater pump operability test.
OSP-AL-V0001C Turbine driven auxiliary feedwater valve operability test.
OSP-GT-LL160 Containment mini-purge valve leak rate test.
,
MSE-ZZ-QS005 480V molded case circuit breaker functional test on the ' A' containment cooling pump room cooler.
ESP-GK-03012 Control room filtration filter unit train
'B' bypass leakage test.
OSP-SA-00003 Emergency core cooling system path verification and testing.
Chanaeout of canisters and trays in FGK01A On April 16, 1992, the licensee successfully restored the 'B'
train control room filtration and adsorber unit to service after analysis of the last test canister showed degradation of the charcoal.
The unit was declared inoperable on April 12, 1993, after.the unit failed an off-site analysis test of a charcoal canister. At that time, the licensee entered the appropriate seven-day action statement for TS 3.7.6.
The test canister's failure was unexpected as. trending of past data, tracked by the system engineer, did not indicate the charcoal was degraded.
For example, the results from the previous canister tested had an efficiency of 99.48 percent; however, an efficiency of only 97.44 percent was obtained for the current test. The charccal efficiency limit was 99 percent.
The SE could not provide any explanation for the unexpected drop in testing results.
In accordance with testing requirements, any canister failure necessitates a changeout of the charcoal trays.
In the past, the
.._
_
.-
.
.-
_.
_ _ _
_
,
_.
'
licensee performed charcoal tray changeouts; however, due to a.
concern raised by the quality assurance department, in March 1993, with respect to the qualification of the refill procedure, the licensee did not pursue refilling the trays.
The program has been revised to have this function performed by a qualified vendor.
The licensee developed the tray refill procedure based on the
vendor's procedure, for changeout of deep bed adsorbers (DBAs).
.
'
Since this refill method for DBAs allowed charcoal to drop freely in the bed, the licensee assumed that the same procedural approach
'
for refilling the trays should have also been acceptable.
However, the procedure had not been qualified according to the code requirements. As such, the concern of settling of charcoal over time arose.
Since the units have been successfully tested periodically, there has been no negative impact on the
>
functionality of the units as a result of the charcoal settling.
A review of the maintenance work history for the filtration units
'
indicated that the' licensee had used an unqualified procedure on three occasions for safety-related equipment and on two occasions for non-safety-related units.
'
By promptly addressing this issue, the potential to exceed the TS action statement was minimized. After the trays arrived onsite and were verified by quality control, mechanics installed the trays.
A bypass leakage test (BLT) was. satisfactorily performed on the unit and the licensee exited the applicable TS.
Prior to
'
dumping charcoal, the SE obtained samples from one of the trays and sent it for analysis. One was sent to the same laboratory while the other sample was sent to a different laboratory; both samples were found to be within the acceptable limits.
These results indicated that the initial sample results were in error.
In addition to performing the BLT, the SE was also conducting troubleshooting activities on the control room air conditioning unit, SGK04A. The system engineer used the local control switch to reset SGK048 after finding the unit in a tripped condition.
The SE's-action was in response to complaints from the control room staff about high temperatures in the control room.
However, the engineer did not receive the proper authorization nor did he inform the control room of his intentions to reset the unit.
The unit did not restart after being reset, but indications of unit manipulations were received in the control room; the reactor operator (RO) restarted the unit. The R0 infermed the control
.
room shift supervisor of the incident. The system engineer was l
later counselled by the shift supervisor as a result of the incident.
In an effort to prevent any future occurrences, an occurrence report was generated to document the event and was to be presented at a systems engineering department meeting.
'
>
. _ _
.
_.
_ - _ _ _, _
._
..
Incorrect data used to calibrate radiation monitors On May 11, 1993, the licensee discovered that two safety-related
~
radiation monitors (RMs) had been calibrated using incorrect data.
Investigation of this issue did not-reveal an operability concern since the RMs were set in the conservative direction. This error
'l would have resulted in the RMs performing their functions earlier than required.
While performing surveillances to calibrate the containment atmosphere and containment mini-purge RMs, the technicians identified that the appropriate decay corrected count rate for the
-
calibration source had not been used. This error was discovered while determining the root cause for an unexpected detector response. The calibration source was used to calibrate the gas and particulate channels of several RMs every 18 months in accordance with instrumentation and control (I&C) loop calibration surveillance (ISL) procedures.
In each applicable ISL procedure, there was a procedural step which required the I&C technicians to obtain the decay corrected count rates for the specified sources.
These values were automatically calculated by the I&C data base (spreadsheet).
An I&C foreman would then retrieve the values 'and provided the information to the technicians.
In June 1990, the licensee ordered a new calibration source set
(Cesium-137), to replace the old calibration source set (Chlorine-36) due to leakage problems with one of the old sources.
The Cesium-137 source has a half-life of 30 years, but the old calibration source had a half-life of IE+05 years. When the spreadsheet was updated with~the new source information, the correct half-life value for Cesium-137 was not incorporated. As a result, a decay correction for the source was not implemented resulting in the RMs alarming earlier.
A total of 15 RMs had been affected by this error.
It was fortuitous that the as-left condition of the RMs was such that the monitors would alarm before being required.
Because the potential existed for the RMs to be set nonconservatively, there is a concern that data used for calibrating safety-related equipment was not proceduralized or controlled to ensure that all variables
affected by the new source were properly updated. The lack of
.;
proper maintenance or periodic verification of the data base was also a contributor to this event since the incorrect data was in-place for nearly three years without being identified.
'
The licensee's corrective actions included re-scheduling the two surveillances to perform the applicable sections of the procedures. Also, addition program changes will be made to provide control over the spreadsheet.
,
~
-
-
- - -
--- -.
.
l
.
Conclusions Craft personnel routinely performed in-plant activities in an organized and controlled manner.
,
-
During troubleshooting activities, the SE inappropriately reset the control room air conditioning unit. Also, the lack of program controls was evident, for proper upkeep of the I&C spreadsheet,.as radiation
monitors were calibrated using incorrect data.
No violations or deviations were identified.
5.
Exit-Meetina (71707)
The inspectors met with licensee representatives (denoted under Persons Contacted) at intervals during the inspection period. The inspectors
summarized the scope and findings of the-inspection.
The licensee
'
'
representatives acknowledged the findings as reported herein. The inspectors also discussed the likely informational content of the
-
inspection report-with regard to documents or processes reviewed by the j
inspectors during the inspection.
The licensee did not identify any such documents / processes as proprietary.
>
r
!
i
'I
t
.
. _.