IR 05000285/1998021
| ML20195G442 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 11/13/1998 |
| From: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | |
| Shared Package | |
| ML20195G440 | List: |
| References | |
| 50-285-98-21, NUDOCS 9811200306 | |
| Download: ML20195G442 (17) | |
Text
. -.
-
...-
-
- -..
..
~
.- - -
.
.--
-
..
.
.
.
ENCLOSURE U.S. NUCLEAR REGULATORY COMMISSION
^
REGION IV
Docket No.:
50-285-License No.:
DPR 40 Report No.:
50-285/98-21 Licensee:
Omaha Public Power District.
,
Facility:
Fort Calhoun Station Location:
Fort Calhoun Station FC-2-4 Adm.
P.O. Box 399, Hwy. 75 - North of Fort Calhoun Fort Calhoun, Nebraska Dates:
Sev9mber 27 through November 7,1998 Inspectors:
W. Walker, Senior Resident inspector D. Corporandy, Resident inspector Approved By:
. D. N. Graves, Acting Chief, Project Branch B ATTACHMENT:
Supplemental Information
,
h
,
i 9811200306 981113
?
PDR ADOCK 05000285 G
{
.
_
-
_-
,
.
EXECUTIVE SUMMARY Fort Calhoun Station NRC Inspection Report 50-285/98-21 Ooerations Operations personnel demonstrated excellent control of activities by ensuring
.
maintenance activities inside containment to repair Feedwater Check Valve FW-161 did.
l not interfere with monitoring of safe plant operations (Section O1.1).
Inadequate training was provided for positioning of the mechanical throttle lever for the
diesel-driven auxiliary feedwater pump following the January 1998 event, resulting in an overspeed trip of the pump in September 1998. The inspectors determined that the licensee missed an opportunity following the January event to adequately train operations personnel on how to determine the correct position of the mechanical throttle lever (Section O2.1).
The inspectors determined that leaving the diesel-driven auxiliary feedwater pump
.
engine trip override switch in the Test position did not significantly increase the probability that the pump would be unavailable if needed. The licensee initiated a condition report to ensure further clarification was provided to operations personnel regarding the use of the engine trip override switch (Section O4.1).
Maintenance The inspectors concluded that material condition was good and verified that the licensee
.
had an action plan in place to address the buildup of boric acid on several safety-related
. systems (Section M2.1).
The inspectors observed excellent performance throughout the planning, assessment,
.
and implementation of repair on the feedwater check valve. Especially notaLL was the performance by maintenance supervision in conducting prejob briefings, emphasizing nuclear and personnel safety prior to containment entries for the removal of insulation, and peening and welding on the valve in a hot steam environment (Section M4.1).
Enaineerina System engineering personnel and design ergineering personnel were proactive in
pursuing reliability improvements to the raw water system. The inspector verified that the modification documentation to increase p Jmp impeller size was complete and
' thorough (Section E1.1).
Plant Succort Radiation protection personnel were implementing process improvements to radiation
,
worker practices. Especially notable were the more stringent interviewing techniques of i
plant personnel prior to granting entrance into the radiologically controlled area (Section R1.1).
... -
. - -.
.
l-2-l l
The inspectors identified an operator workaround in the area of radiation monitoring.
.
l Specifically, the backup containment atmosphere radiation monitor had to be removed from service when a containment atmosphere grab sampie was taken. The licensee promptly added this item to the operator workaround list for appropriate corrective action (Section R1.2).
The licensee was self-criticalin the identification of strengths and performance issues
.
during a security force exercise. The exercise provided valuable training for the security force responsible for responding to a radiological sabotage incident (Section S t.1).
Control room operators maintained excellent control of activities during an inadvertent
.
actuation of both fire pumps and a release of carbon dioxide to the exciter housing.
Appropriate procedures were referenced and in use during the event (Section F1.1).
I
!
- - _ _ _ _ _.. _ _
- _. _ _ _
_
1
.
Report Details Summarv of Plant Status The Fort Calhoun Station began this inspection period at 100 percent power and maintained that level throughout the inspection period. On October 5,1998, a leaking feedwater check valve was discovered inside containment. The repair of the feedwater check valve was accomplished at power and completed on October 22,1998.
l. Operations
Conduct of Operations O1.1 General Comments (71707)
The inspectors conducted frequent reviews of ongoing plant operations. In general, the conduct of operations was professional and safety conscious. Operations personnel demonstrated excellent control of activities by ensuring maintenance activities inside containment to repair Feedwater Check Valve FW-161 did not interfere with monitoring of safe plant operations.
Operational Status of Facilities and Equipment O2.1 Diesel-Driven Auxiliary Feedwater Pump Oversoeed Trio (71707)
a.
Insoection Scope The inspectors reviewed the overspeed trip of the diesel-driven auxiliary feedwater pump during monthly testing, b.
Observations and Findinos On September 28,1998, during performance of a monthly run of the diesel-driven auxiliary feedwater pump, the engine tripped due to an overspeed condition. Although the diesel-driven auxiliary feedwater pump is not safety-related, it is considered risk-significant and is factored into the plant's probabilistic risk assessment. The engine is normally set to run at approximately 1800 rpm and the trip setpoint is 1944 rpm. At the time of the overspeed condition, the auxiliary feedwater system was aligned for an initial 10-minute line flush.
The inspectors questioned the licensee concerning whether any overpressurization of auxiliary feedwater piping had occurred due to the overspeed. The system engineer provided an engineering calculation which confirmed that the pump and piping were designed for conditions that would occur during an overspeed condition since the pump tripped at the designated trip setpoint.
The licensee inspected the mechanical throttle lever on the engine and determined that the mechanical throttle lever was mispositioned, which resulted in the engine overspeed condition. The inspectors questioned the licensee concerning the cause of the mechanical throttle lever mispositioning. The licensee stated that the only time the (
- - _ _ _ _ _ _ _ _
..
.
-
. - ~ - -.
.-
'
2-mechanical throttle lever position is adjusted is when maintenance has been performed such as an oil change on the pump. The inspectors reviewed the maintenance history on the pump and were unable to identify any maintenance which occurred since the last monthly run of the pump. Since no maintenance had occurred, the pump's mechanical throttle lever position should not have been changed.
The inspectors discussed with the licensee the training of the equipment operators concerning the walkdown of the pump prior to starting and the pump setup checklist contained in Preventive Maintenance Procedure OP-PM-AFW-0004," Third Auxiliary Feedwater Pump Operability Verification." The setup checklist contained a step which indicated that positioning of the engine mechanical throttle lever to the full open position should be verified.
During discussions with the licensee, the inspectors determined that the operators had not been adequately trained on the positioning of the mechanical throttle lever and that a similar event had occurred in January 1998 when the pump was supposed to come up to idle speed (approximately 1300 rpm) and only reached 500 rpm. This was determined to be a misunderstanding by the equipment operators of how the mechanical throttle lever positioning worked. Training was conducted with the operations personnel following the January 1998 event to show operations personnel how to adjust the mechanical throttle lever, and a picture was added to the preventive maintenance operating instruction to show proper positioning of the mechanical throttle lever. However, the training was inadequate in that operations personnel did not understand that the mechanical throttle lever could be rotated 180 degrees and
'
mispositioned in such a way that would not be easily recognized by operations personnel assigned the task of verifying the correct positioning of the lever.
As corrective actions for this most recent event, operations personnel were given additional training on the operation of the mechanical throttle lever, a more detailed diagram for proper positioning of the mechanical throttle lever was included in the operating procedure, and an alignment strip was placed on the mechanical throttle lever to allow for easy identification and verification that the mechanical throttle lever was in the correct position.
c.
Conclusion inaduquate training was provided for positioning of the throttle lever for the diesel-driven auxiliary feedwater pump following a January 1998 event, resulting in an overspeed trip of the pump in September 1998. The inspectors determined that the licensee missed an opportunity following the January event to adequately train operations personnel on how to determine the correct position of the mechanical throttle leve _
.
-3-O2.2 Review of Eauioment Tacouts (71707) -
~
The inspectors reviewed the following tagout:
Serial Number 98-1565, Service Air System Header Pressure Alarm Isolation
.
The inspectors found all tags were'on the proper components and that components were in the required position.
. Operator Knowledge and Performance
,
04.1 ~ Operational Status of the Diesel-Driven Auxiliary Feedwater Pumo a.
Inspection Scope (71707)
The inspectors observed the performance of the preventive maintenance test to verify the operability of the diesel-driven auxiliary feedwater pump, b.
Observations and Findinaa On October 30,1998, the inspectors observed portions of the monthly full flow preventive maintenance test of the diesel-driven auxiliary feedwater pump. During the test, operations personnelinitially performed a'10-minute run of the pump to flush any corrosion products and then obtained a chemistry sample for analysis to ensure that -
sodium, chloride, and sulfate were within the limits for the condensate tank.
The' diesel-driven auxiliary feedwater pump was then aligned for the full flow test. The inspectors noted that approximately 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> passed between when the flush of the system was performed and the full flow run was performed. During the 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />, the inspectors observed that the engine trip override switch was in the Test position versus the C'1ergency Standby position.
The inspectors questioned operations personnel on whether this was acceptable. The control room operators stated that according to the procedure the switch was in the correct position. The inspectors were informed that, with the engine trip override switch in Test, all trips for the engine were activated. When the engine trip override switch is in the Emergency Standby position, the engine automatic trips are bypassed.
The inspectors questioned the licensee on the risk significance of allowing the test configuration to exist for 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> due to the fact that the diesel-driven auxiliary feedwater pump is listed as one of the top 10 components important to core damage prevention.
The licensee informed the inspectors that positioning the engine trip override switch in the Test position for 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> did not significantly increase the probability of the diesel-driven auxiliary feedwater pump being unavailable if neede.
.
The licensee initiated a condition report to review the preventive maintenance procedure for the monthly run of the diesel-driven auxiliary feedwater pump and add enhancements to the procedure if necessary, c.
Conclusions The inspectors determined that leaving the diesel-driven auxiliary feedwater pump engine trip override switch in the Test position did not significantly increase the probability that the pump would be unavailable if needed. The licensee initiated a condition report to ensure further clarification was provided to operations personnel regarding the use of the engine trip override switch, 11. Maintenance M1 Conduct of Maintenance M1.1 General Comments a.
Insoection Scoce (62707)
The inspectors observed all or portions of the following maintenance activities:
Change Out of Diesel Generator 1 Radiator Fluid
.
Troubleshooting Temperature Control Valve on the Stator Cooler
.
Replacement of Raw Water Pump AC-10D
-
Repair of Service Air Valve CA-123
.
b.
Observations and Findinas The inspectors found the work performed under these activities to be professional and thorough. All work observed was performed with the work package present and in active use. Maintenance technicians were experienced and knowledgeable of their assigned tasks. The inspectors frequently observed supervisors and system engineers monitoring job progress, and quality control personnel were present when required by procedure.
c.
Conclusions i
The maintenance activities observed were conducted in a controlled and professional manne _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _
.
-5-M1.2 Surveillance Tests
- a.
Insoection Scope (61726)
The inspectors observed all or portions of the following surveillance activities:
OP ST-DG-0001," Diesel Generator 1 Check," Revision 24;
.
OP-ST-ESF-0010, " Channel B Safety injection, Containment Spray and
.
Recirculation Actuation Signal Test," Revision 27; OP-ST-RW 3031, "AC-10D Raw Water Pump Operability inservice Test,"
a Revision 19; OP-ST-FP-0001C, " Fire Protection System inspection and Test," Revision 6;
.
and, OP-PM-APN-0004, " Third Auxiliary Feedwater Pump Operability Verification,"
.
Revision 15.
b.
Observations and Findinas Surveillance activities were generally completed thoroughly and professionally, c.
Conclusions The surveillance activities observed by the inspectors were completed in a controlled manner and in accordance with procedures.
M2 Maintenance and Material Condition of Facilities :..d Equipment M2.1 Review of Material Condition Durina Plant Tours a.
Insoection Scoce (62707)
During this inspection period, the inspectors performed routine plant tours and evaluated plant material condition.
b.
Observations and Findinas The inspectors observed that the material condition and housekeeping of accessible areas of the auxiliary building, the radwaste building, the intake structure, and most areas of the turbine building were good.
During a tour of the auxiliary building, the inspectors noted small amounts of dry boric acid buildup on a flange on one of the boric acid pumps and dry boric acid was observed
!
- _ _ _ - - _ -
_
_
.
.
,
6-i around the pun.p seal areas and on the base plates of several of the safety-related pumps. This was discussed with the licensee, and the inspectors verified that an action plan was in place to address the buildup of boric acid.
,
The inspectors observed that the licensee was continuing painting preservation efforts in the turbine building basement.
'
c.
Conclusions The inspectors concluded that material condition was good and verified that the licensee had an action plan in place to address the buildup of boric acid on several safety-related systems.
M4 Maintenance Staff Knowledge and Performance M4.1 Reoair of Feedwater Check Valve FW-161
]
a.
Insoection Scope (62707)
The inspectors followed up on the repair of leaking Feedwater Check Valve FW-161.
- b.
Observations and Findinos On October 8,1998, the licensee made a containment entry to sample safety injection tanks and look for a possible leak inside containment. Based on containment sump readings, the licensee suspected that an approximately 4-gallon per hour leak was present. During the containment entry, licensee personnel identified that Feedwater Check Valve FW-161 was leaking. Check Valve FW-161 is a 16-inch swing disc check valve that functions to prevent blowdown of a steam generator through the feedwater line in the even; c.? a feedwater line break upstream of the check valve.
The licensee determined that the leak was not getting worse and that adequate time
'.
was available to completely plan the course of action necessary to ensure proper repair of the valve was accomplished.
Based on experience, the licensee anticipated that the leakage was coming from the threaded retainer plug which normally retains and seals the hinge pin or stop pin. The
.
initial work required obtaining a proper analysis to ensure that scaffolding could be erected to facilitate work on the valve while at power. The scaffolding construction package and the temporary modification package for repair of the valve were reviewed by the inspectors and found to be complete. Following completion of the scaffolding, maintenance personnel removed the blanket insulation surrounding the valve and verified that the leak was from the threaded retainer plug. The licensee then proceeded with repair of the valve, which consisted of peening around the plug to stop the leak and welding a stub tube over the retainer plug to ensure that the leakage would remain
-_.
.
--
-
-.
.
_ --
-.
. - - ---
.
.
-7-stopped. The repair was completed on October 22,1998, and the scaffolding was removed with the containment returned to normal operating condition on October 26, 1998, c.
Conclusions The inspectors observed excellent performance throughout the planning, assessment, i
and implementation of repair on the feedwater check valve. Especially notable was the performance by maintenance supervision in conducting prejob briefings, emphasizing nuclear and personnel safety prior to containment entries for the removal of insulation, and peening and welding on the valve in a hot steam environment.
Ill. Enaineerina E2 Engineering Support of Facilities and Equipment E1.1 Raw Water Pumo Imoeller Modification a.
Insoection Scoce (37551)
The inspectors reviewed the licensee's modification package to address high wear rates on the raw water pumps and frequent need for impeller replacement.
b.
Observations and Findinas On March 3,1997, the licensee placed the raw water pumps in Category A(1) of the maintenance rule due to chronic high wear rates on the raw water pumps and the frequent need for impeller replacement. The frequent impeller replacement was required to ensure adequate raw water pump hydraulic performance could be maintained above the minimum operability limits.
The licensee initiated Modification 97-027 to increase the size of the pump impellers.
This modification was initiated after extensive efforts were conducted using various material upgrades to the impellers and pump bowlliners to increase service life, with limited success. The high wear rates were caused by the abrasive river water flow in combination with the type and speed of the pumps. The high wear rates experienced on the raw water pump impellers has resulted in the need for frequent maintenance on the pumps for lift adjustment and impeller replacement.
System engineering personnel and design engineering personnel, in consultation with the pump vendor, determined that increasing the pump impeller size would allow for increasing the pump lift clearance, which would eliminate the excessive wear caused by a closer tolerance between the pump impeller and the pump bowl.
.
.
.
.
.
.....
. _ _ _ _ _. _ _ _ _ _ _ _ _ _ _ _. - _ - _ _ _ _ _ _
_ _ _ _ _ _
.
-8-c.
Conclusions System engineering personnel and design engineering personnel were proactive in
,
pursuing rehability improvements to the raw water system. The inspector verified that the modification documentation to increase pump impeller size was complete and thorough.
E8 Miscellaneous Engineering Issues E8.1 (Closed) Licensee Event Report (LER) 50-285/96-012: potential for vaporizing cooling water in containment fan cooling units. In retponse to NRC Generic Letter 96-06, the licensee evaluated the plant response to either a loss of offsite power coincident with a main steam line break inside containment or a loss of offsite power with a loss of coolant accident. After performing calculations for both scenarios, the licensee concluded that, for the case of loss of offsite power coincident with a loss of coolant accident, some vaporization of the component cooling water could occur in the containment air cooling and filtering units, thereby creating the potential for waterhammer upon restart of the component cooling water pump. Licensee calculations showed that component cooling water vaporization would not occur for the scenario of offsite power coincident with a main steam line break.
The licensee event report described the temporary compensatory actions to raise the pressure of the component cooling water surge tank and the attendant temporary modifications to the component cooling water system to allow the minimum operating pressure to be raised from 20 psig to 34 psig.
Subsequent to the temporary modification, a permanent modification was implemented to accomplish the following:
Increase design pressure in various portions of the component cooling water
.
system, including changing set points for 10 thermal relief valves; Relocate component cooling water Surge Tank Pressure Indicator PIC-2802 to
.
the front of the control room for easier monitoring, change the component cooling water surge tank alarm to a low pressure alarm at 36 psig, add a local pressure gauge for the component cooling water surge tank; and Add redundant isolation valves on the demineralized water and nitrogen gas
.
makeup lines to the component cooling water surge tank in order to provide backup isolation points for those lines in the event that the existing primary isolation valves fail their leak test.
The inspectors confirmed that the permanent corrective actions to eliminate the potential for component cooling water waterhammer were appropriate, had uridergone a valid 10 CFR 50.59 evaluation, and were complet _ -
.
_ _.
-
. - -.
.
.
.-.
-- -
-
- _ - - _.
_
-
l-9-
!
E8.2 (Closed) Violation EA 96-489 (01014): two examples of failure to follow procedures:
(1) after the in-line isotopic analyzer had been disabled in August 1995, plant personnel l
failed to revise or cancel a preventive maintenance order which required drawing a l
containment atmospheric sample utilizing the analyzer; and (2) a preventive (
maintenance order (to perform containment atmospheric sampling) was administratively closed without the plant manager's approval.
The inspectors verified the corrective actions described in the licensee's response letter, dated March 31,1997, to be reasonable and complete. No similar problems were identified.
l E8.3 (Closed) Violation EA 96-489 (02014): failure to follow procedures when configuration changes to the postaccident sampling system were made prior to completion and issuance of an engineering change notice.
'
The inspectors verified the corrective actions described in the licensee's response letter,
!.
dated March 31,1997, to be reasonable and complete. No similar problems were
!-
identified.
IV. Plant Support R1 Radiological Protection and Chemistry Controls R1.1 Radiation Worker Practice Process Imorovement Plan a.
Inspec'on Scope (71750)
l The inspectors assessed the licensee's efforts to determine worker's skills and l
knowledge prior to entering the radiologically controlled area.
!
b.
Observations and Findinos
!
l During the inspection period, the inspectors made numerous tours throughout the j
l radiologically controlled area. The inspectors noted an increased effort by radiatiot, l
protection personnel to ensure that plant personnel were aware of the radiological j
l conditions inside the radiologically controlled areas. Radiation personnel, at the
'
l entrance to the radiologically controlled area, c.uestioned plant pe,rsonnel on all work that was to be performed inside the radiologically controlled area. Questions were
'
asked concerning where work was to be performed and what dose rates could be expected in each area entered. The inspectors noted several instances where radiation protection personnel had plant workers perform further review of radiation survey maps to ensure that plant workers had adequate knowledge of radiological conditions.
,
.
.
-
_.
- - - - -
_
- ---
. - _ - -. - ~..
.
I
'
,
-10-c.
Conclusions Radiation protection personnel were implementing process improvements to radiation worker practices. Especially notable were the more stringent interviewing techniques of plant personnel prior to granting entrance into the radiologically controlled area.
,
i R1.2 Radiation Monitor Operator Workaround a.
Inspection Scope (92904)
.
The inspectors identified an operator workaround during containment atmosphere grab j
sampling.
'
b.
Observations and Findinos On October 27,1998, during a routine review of the control room logs, the inspectors identified what appeared to be an operator workaround. The inspectors noted that containment air particulate and gaseous Monitors RMO-50 and -51 were out of service for repair. The control room aperators had placed Ventilation Discharge Duct Monitor RMO-52 in service to monitor containment radiation levels. During review of the control room logs, the inspectors noted that Radiation Monitor RMO-52 had been declared inoperable several times when a containment atmosphere grab sample was required.
The inspectors questioned the contrci room operators as to whether this was an operator workaround. The control room operators stated that Radiation Monitor RMO-52 was declared inoperable due to the fact that when left in service during a containment grab sample it had a tendency to trip. This was attributed to low flow
]
caused by the location of the sampling port for collection of the containment grab i
sample.
The inspectors considered this to be an operator workaround. Subsequently, the licensee is now tracking this item as an operator workaround and has assigned a work request to ensure corrective actions are accomplished.
c.
Conclusions The inspectors identified an operator workaround in the area of radiation monitoring.
Specifically, the backup containment atmosphere radiation monitor had to be removed from service when a containment atmosphere grab sample was taken. The licensee promptly added this item to the operator workaround list for appropriate corrective actio. - _ _ _ _ - _ _ _ _ _ _ _ _ _ _.
-_
_ _ _ _ _ _ _ _ _ ___
___
!
.
-11-S1 Conduct of Security and Safeguards Activities S1,1 Security Exercise a.
Insoection Scoce (71750)
The inspectors observed portions of a security training exercise to demonstrate the security force's ability to protect against the design basis threat of radiological sabotage, b.
Observations and Findinas On October 20,1998, the security force conducted an exercise to demonstrate the security force's ability to protect against the design basis threat of radiological sabotage.
The exercises required the security force to recognize and evaluate the threat and respond in an appropriate manner.
The inspectors observed that the licensee had predesignated scenarios, which each of the controllers for the exercise were familiar with, and the scenarios were diverse and realistic. Prior to the start of any of the exercise scenarios, proper plant announcements were made to inform site personnel that a security drill was commencing and announcements were made when the exercises had terminated. All of the exercises were well controlled, conducted in a professional manner, and demonstrated the security force's ability to respond to a radiological sabotage situation.
The licensee identified strengths in tactical movement and improved pedormance in use of concealment. The licensee identified weaknesses in communications and the ability to determine where security force personnel were positioned during a dynamic scenario.
Plans were discussed to provide additional table top training to address these identified weaknesses.
c.
Conclusions The licensee was self-critical in the identification of strengths and performance issues during a security force exercise. The exercise provided valuable training for the security force responsible for responding to a radiological sabotage incident.
F2 Status of Fire Protection Facilities and Equipment F1.1 Inadvertent Start of Both Fire Pumos and Actuation of the Exciter Carbon Dioxide System a.
Insoection Scoce (71750)
t The inspectors followed up on the October 14,1998, unplanned start of both fire pumps and the actuation of the carbon dioxide fire suppression system inside the exciter housing.
!
'
.
.
...
..
.
.
..
.
-12-b.
Observations and Findinas On October 14,1998, at 9:06 a.m., the control room operators observed an unplanned automatic start of both the electric and diesel-driven fire pumps. Also, indications were
,
received that the carbon dioxide fire suppression system inside the exciter housing was discharging and Turbine Generator Fire Suppression Deluge Valve FP-798 actuated and pressurized the main generator spray header up to the spray nozzles. The spray nozzles are kept closed with fusible links and, because no fusible links were activated, no spray occurred.
The control room operators immediately took actions to verify whether an actual fire existed. No fire or smoke was detected. At 9:30 a.m., both the diesel-driven and i
electric fire pumps were shut down, the carbon dioxide system inside the exciter housing was secured, and the deluge valve was isolated.
,
The inspectors noted that, during the event, control room operators were referencing the appropriate procedures and conducted a briefing to inform operations personnel of further actions. System engineers were present to assist in determining the cause for the inadvertent actuations, and required fire impairments were issued for the carbon dioxide system and turbine generator deluge system.
The system engineer contacted the fire protection panel vendor and the vendor performed troubleshooting activities onsite to attempt to identify the cause of the inadvertent actuation. The vendor was unable to determine any obvious cause for the inadvertent actuation. The system engineers, with input from the vendor, identified the following course of action:
Replace all of the circuit boards in Fire Detection Panel Al-153 which ccntrol the
.
inadvertent signals received; Send the removed circuit boards to the vendor for failure analysis and
.
determination of generic implications for other fire detection panels; Perform testing on new circuit boards to ensure proper fire detection capability in
.
the turbine building, service building, water plant and intake structure; and Recharge the carbon dioxide system fire suppression sys.em for the exciter and
.
unisolate the deluge valve for fire suppression on the turbine generator, c.
Conclusions Control room operators maintained excellent control of activities during an inadvertent actuation of both fire pumps and a release of embon dioxide to the exciter housing.
Appropriate procedures were referenced and in use during the even. -. _
.
.. _.
.. _. _..
-
.. _
_
..-_.. _ -_- _ _ _ _ _ _._
_..._ __ _...
_ __
.
.
.
i 13-
!
'
V. Manaaement Meetinos X1 Exit Meeting Summary The inspectors presented the inspection results to members of licensee management at the exit meeting on November 9,1998. The licensee acknowledged the findings as presented.
The inspectors asked the licensee whether any materials examined during the inspection should be considered proprietary. No proprietary information was identified.
r i
I l
l
.
-
-
-
.--
_
.
_
._ _ ___...___
_
._ _ _..
_
__
._
w
.
ATTACHMENT SUPPLEMENTAL INFORMATION PARTIAL LIST OF PERSONS CONTACTED Licensee M. Bare, System Engineer D. Buell, System Engineer D. Dryden, Station Licensing Engineer C. Fritz, System Engineer S. Gambhir, Division Manager, Engineering and Operations Support R. Short, Assistant Plant Manager R.'Jaworski, Manager, Design Engineering Nuclear J. McManus, Supervisor, Engineering Mechanics i
M. Puckett, Acting Manager, Radiation Protection
'
O. Spires, Manager, Quality Assurance and Quality Control INSPECTION PROCEDURES USED IP37551:
Onsite Engineering
)
IP 61726:
Surveillance Observations
'
IP 62707:
Maintenance Observations IP 71707:
Plant Operations IP 71750 Plant Support Activities IP 92904 Followup Plant Support i
ITEMS OPENED. CLOSED. AND DISCUSSED Closed 50-285/98-012 LER Potential for Vaporizing Cooling Water in Containment Fan Cooling Units (Section E8.1)
EA 96-489 (01014)
VIO Failure to Follow Procedures After Disabling a In-line Isotopic Analyzer (Section E8.2)
EA 96-489 (02014)
VIO Failure to Follow Procedures When Configuration Changes to the Postaccident Sampling System Were Made (Section E8.3)
I
.n-