IR 05000123/2002015
| ML17291A704 | |
| Person / Time | |
|---|---|
| Site: | Columbia, University of Missouri-Rolla  |
| Issue date: | 03/20/1995 |
| From: | Chamberlain D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | |
| Shared Package | |
| ML17291A703 | List: |
| References | |
| 50-397-94-34, NUDOCS 9503240165 | |
| Download: ML17291A704 (42) | |
Text
ENCLOSURE
U.S.
NUCLEAR REGULATORY COMMISSION
REGION IV
Inspection Report:
50-397/94-34 License:
NPF-21 Licensee:
Washington Public Power Supply System 3000 George Washington Way P.O.
Box 968, MD 1023 Richland, Washington Facility Name:
Washington Nuclear Project-2 Inspection At:
Richland, Washington Inspection Conducted:
January 23 through February 15, 1995 Inspector:
S.
Campbell, Resident Inspector, Arkansas Nuclear One Approved:
wig t
.
am er ann, Acti g C ie
,
roJect rane Date Ins ection Summar Areas Ins ected:
A special inspection was conducted to evaluate the three events which resulted in emergency filtration system being rendered inoperable as described in three separate licensee event reports (LERs).
Results:
Four apparent violations were identified:
(1)
The first apparent violation involved the failure to perform a
plant shutdown as required by Technical Specification (TS) 3.7.2.a when one emergency filtration system train was inoperable because of a missing gasket on the air handling unit access door (Section 3.4).
(2)
The second apparent violation involved the failure to initiate and maintain an operable emergency filtration system in the pressurization mode of operation as required by TS 3.7.2.b (1)
when one emergency filtration system train was inoperable because a filter unit was not able to efficiently remove iodine as a
result of a wetted charcoal filter located inside a filter unit (Section 3.1).
9503240i65 950320 PDR ADQCK 05000397
e V
(3)
The third apparent violation involved the failure to perform a
plant shutdown as required by TS 3.0.3 when both emergency ventilation systems were inoperable because of holes opened in the control room boundary (Section 3.5).
(4)
The fourth apparent violation involved a failure of established measures to ensure that conditions adverse to quality with regard to the emergency filtration system were promptly identified and corrected as required by Criterion XVI of Appendix B to
CFR Part 50 (Section 6).
There were missed opportunities to assess and identify an inoperable emergency filter unit because operators did not initiate a problem evaluation report when water was noted leaking from a deluge spray telltale drain.
Lack of equipment operator training on deluge system interface with the filter unit and lack of a questioning attitude by the senior reactor operator screening the work request contributed to the missed opportunity (Section 3. 1).
The operability of the emergency filtration system was indeterminate because the system engineer did not quantify Door 4 leakages when the door was discovered with a blown seal.
The emergency filtration system operability remained indeterminate after gasket repairs were performed because of inadequate postmaintenance testing (PHT) (Section 3.2).
The emergency filtration system operability was indeterminate following the discovery of a missing gasket on Door 6.
The system engineer did not process a problem evaluation request (PER) nor was a test performed in the emergency mode to determine if the emergency filtration system could pressurize the control room above TS minimum while the leakage existed.
The PHT following repairs to Door 6 was inadequate to identify that the emergency filtration system was inoperable with the Door 3 gasket also missing (Section 3.3).
Haintenance craftsmen inspected the emergency filtration system without notifying the control room and without an approved work order.
The craftsmen performed an unauthorized modification as directed by their supervisor by removing the Door 3 gasket, which rendered the unit inoperable.
The work request to repair the Door 3 gasket was delayed because of miscommunication between maintenance personnel.
The senior reactor operator screening the work request missed identifying the inoperable air handling unit with the gasket missing because of a lack of a questioning attitude about system operability which prompted further delays in repairing the door.
No PER was written (Section 3.4).
Craftsmen opened two holes to install a plant modification in the control room boundary which rendered both emergency filtration system trains inoperable.
The control room operators approved the work package without entering a limiting condition of operation (LCO).
Planning
procedures provided vague guidance in identifying impact to the control room boundary as a result of the modification installation.
The safety evaluation did not identify that the emergency filtration system would be impacted as a result of the modification installation because the safety review did not account for all phases of the installation process (Section 3.5).
~
The licensee generally performed an acceptable review of each event as documented in the LERs.
However, the inspector identified instances where the licensee could have been more thorough and the inspector noted several missed opportunities to have identified the problems earlier (Sections 4, 5, and 6).
~
The licensee determined that the potential thyroid dose to the operator without an operable emergency filtration system was low based on the eighth refueling outage local leak rate data.
The inspector was not provided any information by the licensee on the potential thyroid dose based on the ninth refueling outage local leak rate data or based on a
design basis leak rate (Section 7).
Summar of Ins ection Findin s:
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Apparent violation 397/9434-01
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Apparent violation 397/9434-02
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Apparent violation 397/9434-03
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Apparent violation 397/9434-04 Attachment:
was opened (Section 3.4).
was opened (Section 3. 1).
was opened (Section 3.5).
was opened (Section 6).
~
Attachment Persons Contacted and Exit Meeting
DETAILS
LICENSEE EVENT REPORTS LERs 397/94-12, 397/94-19, and 397/94-21 described three self-disclosing events which resulted in the emergency filtration system, a safety-related system, being.inoperable for an extended period.
These events affected the ability of the emergency filtration system to remove radioactive iodine and to pressurize the control room.
These events occurred on March 30, October 26, and November 23, 1994, respectively.
These events collectively appeared to represent a breakdown in activities associated with the design, maintenance, testing, and operation of the emergency filtration system and the licensee's corrective action program.
The purpose of the inspection was to conduct interviews, and review the chronological sequence of events leading up to the discovery of the inoperable emergency fi,ltration system in order to evaluate the licensee's corrective actions and root cause determinations.
The inspector also included in this review NRC Inspection Report 50-397/95-01, which discussed the potential radiological consequences as a result of the emergency filtration system being inoperable.
A discussion of each self-disclosing event as described in the corresponding LER is provided below.
1. 1 LER 397 94-12:
Emer enc Filter Unit WMA-FU-.54B Ino erable Due to Leakin Delu e
Su
Isolation Valve This LER described a condition where water leakage past Deluge System Isolation Valve FP-V-WMA/21 rendered Emergency Filter Unit WMA-FU-54B of the emergency filtration system inoperable.
On June 23, 1994, the licensee declared Train 8 of the emergency filtration system inoperable after discovering approximately 5 inches of water in the bottom of the filter unit.
Water in the filter unit affected the charcoal filter's ability to remove radioactive iodine such that the requirements of TSs could not be met.
The licensee determined that the source of the water was leakage past Deluge Isolation Valve FP-V-WMA/21.
The licensee discovered the leakage on March 30, 1994, and generated a work request to repair the leaking valve, but did not assign a date to perform the repairs.
Only after the wetted charcoal was identified by the licensee on June 23, 1994, was the valve repaired.
The licensee determined that Train B of the emergency filtration system was apparently inoperable beginning on May 31, 1994, when water had actually been observed coming out of the bottom drains of Emergency Filter Unit WMA-FU-54.2 LER 397 94-19:
Gasket Missin from Main Control Room Air Handler WMA-AH-51B Precludes Associated Emer enc Filter Fan WMA-FN-54B from Sufficientl Pressurizin the Control Room This LER described the failure of the Emergency Filter Fan WMA-FU-54B to pressurize the control room to the TS minimum requirement during surveillance testing on November 21, 1994.
The test failed because gasket material had been removed from Door 3 on Air Handling Unit WMA-AH-51B during the troubleshooting of high control room temperature on October 26, 1994.
The gasket, if installed properly, would have prevented or limited air leakage past the doors and was required to maintain the integrity of control room boundary.
Control room pressurization is a design basis feature for maintaining control room habitability and protecting operators from radiological contamination in the control room following a design basis accident.
The licensee discovered that without the Door 3 gasket, the emergency filtration system was unable to perform its design function.
Maintenance personnel removed the Door 3 gasket following troubleshooting on October 26, 1994.
The missing gasket apparently rendered the emergency filtration system inoperable until November 23, 1994, when the gasket was replaced and the system passed the surveillance test.
1.3 LER 397 94-21:
Holes Cut in Main Control Room Floor Penetration 5016 Precludes Redundant Emer enc Filter Fans WMA-FN-54A B from Pressurizin the Control Room Sufficientl to Meet the A
licable Surveillance This LER described the inoperability of both trains of the emergency filtration system on November 23, 1994, after the licensee discovered that two holes had been cut through the control room to cable spreading room floor on November 22,'994.
This condition was discovered after the repairs of the Door 3 gasket (reported in LER 94-19)
and during the surveillance test of Train B of the emergency filtration system to assess the effectiveness of repairs.
Maintenance craftsmen had received approval to cut the holes through an existing penetration in accordance with an approved work order.
The work order installed electrical conduit for a modification associated with installing adjustable speed drives (ASD) for the reactor recirculation pumps, The holes prevented the control room from pressurizing above the TS minimum requirement of a positive 0. 125 inches water gauge (wg).
After discovering that the holes rendered both trains of the emergency filtration system inoperable, the licensee resealed the holes, reperformed the surveillance test, and declared Train B of the emergency filtration system operable after it had successfully passed the surveillance tes SYSTEM DESCRIPTION 2. 1 Desi n Basis of the Control Room Ventilation S stem CRVS and Emer enc Filtration S stem The design basis of the CRVS is to maintain the control room between 72'F and 78'F during normal operation and less than 104'F during accidents.
Additionally, the CRVS reduces smoke ingress, combustible vapors, and radioactive contaminants by maintaining the control room at a positive pressure.
During a loss-of-coolant accident, the CRVS is designed to maintain a positive pressure of 0. 125 inches wg and remove radioactive iodine through an emergency filtration system.
2.2 Descri tion of the CRVS To achieve these design requirements, the WNP-2 CRVS consists of two 100 percent capacity Trains A and B.
Each train can be operated in the normal or emergency mode.
In the normal mode, each train is aligned to include a Supply Fan WHA-FN-51A or WMA-FN-518 which takes air suction from a common air intake and two remote air intakes.
The fan blows approximately 20,000 standard cubic feet per minute (scfm) of air through an air handling unit.
A common duct distributes the air within the control room.
To equalize equipment operating time, the licensee periodically switches the operating train.
During the normal mode of operation, Exhaust Fan WEA-FN-51 continuously removes air from the control room via separate exhaust ducting.
Each Air Handling Unit (WHA-AH-51A and WHA-AH-51B) consists of two water cooling coils, one for normal cooling (supplied by the radwaste chilled water cooling system)
and one for the emergency mode (supplied by standby service water), roll filters, and a 50 kW electric blast coil heater.
The temperature and humidity are controlled by electronic controllers located in the control room which modulate the chilled water flow to the cooling coil.
Roll filters are used to remove particles from the air.
The heating coil helps in maintaining control room temperature.
Each train of these components is located inside a metal enclosure.
Six doors provide access to the components located in the enclosure.
Each door has a
gasket at the sealing surfaces that seals the units'oors to maintain the integrity of the control room boundary.
These gaskets are necessary so that the control room pressurizes to a minimum positive pressure of 0. 125 inches wg.
The metal enclosures are part of the control room boundary during both normal and emergency operations.
During a design basis.accident, the CRVS is designed to automatically shift from the normal to the emergency operating mode to include the emergency filtration system when any of the following occur:
a reactor vessel low water level, a high drywell pressure, or a high radiation level in the reactor building exhaust system.
During the transition from the normal to the emergency ventilation mode, the following automatic actions occur:
(1) the outside air intake dampers close (leaving the two remote intakes in service),
(2) the supply and discharge dampers to the emergency filtration units open, (3) suction valves for the Supply Fans WMA-FN-51A and WMA-FN-51B reposition to recirculate air instead of supply air, and (4) the emergency filter system fans start to provide approximately 1000 scfm of makeup air.
Exhaust Fan WEA-FN-51 trips when either emergency filtration fan starts.
Each emergency filtration system'onsists of the following:
( 1) emergency filter units accommodating Emergency Filter Fans WMA-FN-54A or WMA-FN-548 with a medium efficiency prefilter, a high efficiency particulate filter, and a
charcoal absorber carbon filter located upstream of the emergency filter fans inside a metal enclosure; (2)
a
kW heater to limit the relative humidity of the air entering the filter to 70 percent; (3) bypass and recirculation control dampers and associated ductwork.
The emergency filter fans operate with the supply fans.
The fans pressurize the control room to a minimum positive pressure of 0. 125 inches wg with respect to the pressure in the cable spreading room.
Differential Pressure Indicator WMA-DPI-7 indicates the pressure difference between the control room and the cable spreading room.
The cable spreading room is located directly below the control room.
The control room is typically at a pressure greater than the cable spreading room.
3 " SUMMARY OF ISSUES AND CHRONOLOGY OF EVENTS Between March 30 -and November 23, 1994, licensee operators, craftsmen, and engineers performed the following on the CRVS:
walk downs, modifications, maintenance, and tests on components of the CRVS'and its boundaries.
In certain instances, the licensee identified equipment deficiencies as a result of these activities.
Generally, the licensee documented the deficiencies by issuing serialized priority-based work requests.
The work requests listed the originator, work request details, and the time and date of the deficiency.
Senior reactor operators (SROs)
screened the work requests to determine if the deficiency rendered the equipment inoperable.
Subsequently, the licensee generated work order tasks (WOTs) which provided instructions to repair the deficiency listed on the work request.
The licensee based the work completion due, late, and need dates on the assigned priority listed on the WOT.
The licensee scheduled the work based on the work completion due, late, and the need dates.
The licensee ultimately initiated PERs on several occasions where safety-related equipment was degraded or inoperable.
3. 1 Emer enc Filter Unit WMA-FU-54B Ino erable Due to Leakin Delu e
Su l
Isolation Valve On March 30, 1994, an equipment operator (EO) identified that Deluge Spray Isolation Valve FP-V-WMA/21 was leaking past its seat.
Deluge Spray Isolation Valve FP-V-WMA/21 is the only closed isolation valve between the fire water (150 pounds per square inch)
and the charcoal of the emergency filtration unit.
Approximately 60 feet of 1-inch pipe and a vertical distance of about 6 feet separate Deluge Spray Isolation Valve FP-V-WMA/21 from the emergency
filter unit.
The deluge spray system provided the capability to manually soak the charcoal filters in case of high temperatures.
On March 31, 1994, an EO initiated a Priority 3 Work Request 94001683 to repair Deluge Spray Isolation Valve FP-V-WHA/21.
The licensee considered that the work was low priority because the leak rate from the telltale drain was low (approximately 1 drop per second).
The 'licensee assumed that the leakage would be directed to a nearby drain and the leakage would not migrate to the charcoal filter because a strainer, a reducer, and an orifice via the 1/4-inch drain line located downstream of the leaking valve would remove any leakage.
In evaluating the leaking valve, the licensee did not consider that the orifice could only pass a very limited water volume (drops per second)
because the small orifice, which was 0.046-inch diameter, was not able to pass a high water volume.
The orifice was intended to be a telltale indication of a leakage problem and the licensee did not recognize that the leakage could possibly render the charcoal filters inoperable.
This design feature was apparently not understood by the EO or by others in the licensee organization.
Therefore, the licensee did not perform a prompt operability assessment or document the problem in a
PER.
This failure to document the problem in a PER represented a missed opportunity for early identification and corrective action for the problem and for potentially avoiding charcoal filter inoperability and damage.
On May 22, 1994, with the plant shutdown, a different EO performed routine flush of the deluge station that serves Emergency Filter Unit WMA-FU-548.
The EO found material in the strainer located on the 1/4-inch line.
The EO removed the material from the strainer and noted that water no longer dripped from the drain.
On Hay 31, 1994, the control room operators received a report that water was draining from the bottom drains of Emergency Filter Unit WHA-FU-548.
The shift support supervisor (SSS)
dispatched an EO, the individual who cleaned the strainer, to investigate.
The EO discovered water draining from Emergency Filter Unit WMA-FU-548 2-inch drain piping.
The EO opened Deluge Drain Valve FP-V-WMA/23 (a 3/4-inch valve located downstream of the leaking Isolation Valve FP-V-WMA/21) to drain the water from the emergency filter unit.
After approximately 1 to 2 minutes, the water appeared to stop draining from the bottom drains of Emergency Filter Unit WMA-FU-548.
The EO, who had not received training on the design of this system, did not realize that there were four spring-loaded check valves installed on the filter unit drains and that these valves were normally closed.
Therefore, he did not recognize that the charcoal filter was possibly, contaminated with water.
Again, a prompt operability assessment was not performed and a
PER was not written.
This failure represented yet another missed opportunity to have provided for early identification and corrective action for the problem.
On June 23, 1994, as part of a surveillance test, the licensee inspected the charcoal filter of Emergency Filter Unit WMA-FU-548.
When the licensee opened the inspection door, water discharged to the floor.
The licensee initiated
PER 294-0619 and declared the emergency filter unit and emergency filtration system inoperable.
The licensee decided that the unit had been inoperable since May 31, 1994, when the licensee identified the water leaking from the emergency filter unit drain.
The licensee removed the water and declared the unit and emergency filtration system operable after replacing the charcoal filter.
The licensee later determined that the source of the water was the result of leaking Deluge Isolation Valve FP-V-WHA/21 that had been identified as leaking on March 30, 1994.
The inspector reviewed PER 294-0619 and conducted interviews with the licensee's staff and confirmed that Work Request 94001683 was screened by an SRO after it was initiated by the EO on March 31, 1994.
During the work request screening, the SRO did not recognize that the leaking valve potentially impacted the operability of the charcoal filter.
Therefore, the SRO assigned the job a low priority and placed it on the 12-week rolling maintenance schedule.
Through interviews, the inspector discovered that the EO did not understand how the deluge system interacted with the filter.
Although the EO indicated that he was not trained on the system layout, the EO did not reference a
piping and instrumentation diagram to understand the system configuration.
He added that he did not investigate if the Emergency Filter Unit WMA-FU-54B 2-inch drain line, used to drain water from the emergency filter unit, indicated flowing water.
Based on interviews with the second EO, the inspector discovered that he also did not understand the system layout of the deluge system nor its interrelationship with Emergency Filter Unit WHA-FU-54B.
The EO did not realize water impinged on the carbon filter when the water leaked past the isolation valve.
He thought the deluge spray header, located inside the emergency filter unit, sprayed deluge water from below the carbon filter..
In fact, the header was oriented vertically with respect to the filter and sprayed water on the side of the filter when the isolation valve was opened.
The EO thought that the water supplied from the leaking isolation valve only filled up the bottom of the filter unit and did not effect the carbon filter.
The second EO incorrectly concluded that opening the drain valve would empty the filter unit.
The EO notified the control room that the leak stopped after the EO noted that water stopped flowing from the 2-inch drain.
The EO attached a hose to the FP-V-WMA/23 and tagged the drain valve open.
The EO did not recognize that four check valves existed on the bottom of the filter unit.
The EO added that the check valves looked like bronze or brass couplings when he viewed the valves externally.
Neither the EO nor the SSS processed a
PER or performed an operability assessment because of the draining water.
3. 1. 1 Licensee Conclusions The licensee indicated that the telltale drain was a design feature for identifying leakage past the isolation valve, The licensee believed that the
-10-EO appropriately generated a work request to correct the minor leakage, because the work request process is used as a corrective action document and believed that the work request was sufficient to document the leakage initially observed.
II The licensee acknowledged that the second EO did not understand the design of the emergency filter unit drains.
The second EO did not recognize the impact the water might have on the charcoal filter.
Thus, he did not write a PER.
The licensee added that because of the conversation between the second EO and the SSS, the SSS erroneously concluded that the operator stopped the leakage from the deluge station drain.
Therefore, the SSS also did not recognize the need to write a PER For the event.
3. 1.2 Inspector Conclusions The inspector concluded that the leaking deluge isolation valve had rendered the Emergency Filter Unit WMA-FU-548 inoperable t some point prior to May 31, 1994, the date that the licensee determined the unit to be inoperable.
The licensee did not perform any calculation or assessment to determine the amount of time prior to May 31, 1994, that the unit was inoperable, and the potential safety significance, even though it was clear that the point of inoperability occurred at some unknown point prior to May 31, 1994, The inspector further concluded that the licensee did not conform to TS 3.7.2 (b)(l) while in Operational Conditions 4, 5, and while moving irradiated fuel during the following period:
From some undetermined time after March,31, 1994, and before May 31, 1994, to June 23, 1994, the Train B of the control room emergency filtration system was not operable because Emergency Filter Unit WMA-FU-54B was not operable.
The licensee did not initiate and maintain Train A of the control room emergency filtration system in the pressurization mode.
Core alterations occurred during the period up to June 13, 1994.
This is an apparent violation of TS 3.7.2 (b) (397/9434-02).
3.2 Leakin Air Handlin Unit WMA-AH-51B Enclosure Access Door 4 Due to Blown Seal On April 5, 1994, a system engineer (SE) noted air leakage from Air Handling Unit WMA-AH-51B Door 4 as a result of a "blown seal" while Supply Fan WMA-FN-51B operated in the normal mode.
The purpose of the Door 4 gasket was to seal the door surfaces to reduce air leakages and maintain the integrity of the control room ventilation boundary while the air handling unit operated in the normal and the emergency mode.
With a "blown seal," the CRVS's ability to maintain the control room pressurized during the emergency mode operation was questionable.
The amount of air leakage, as a result of the blown seal, was not quantified.
The licensee was unable to conclude that
-11-the air handling unit was able to pressurize the control room to the minimum TS requirement with the blown seal, The licensee did not operate the CRVS in the emergency mode and verify that the pressure on Differential Pressure Indicator WMA-DPI-7 was above the minimum requirement with Door 4 leaking.
Additionally, the SE did not perform an operability assessment and did not initiate a
PER.
The SE generated Work Request 94001798 to identify the repair of "the blown seal."
On June 23, 1994, the licensee repaired'the Door 4 "blown seal" identified on a Priority 3 Work Request 94001798 using instructions listed on WOT JR75 01.
The WOT instructions directed the licensee to remove the damaged gasket and install a
new gasket using cement.
The tasks also instructed the workers to obtain a clearance signoff and start the fan to check for leakage around the new gasketed door.
On June 24, 1994, the licensee performed the leak test as described in WOT JR75 01.
However, the licensee did not confirm that the new gasket was able to withstand elevated pressures while operating in the emergency mode.
The licensee did not verify gasket integrity at higher pressures induced during the emergency operating mode because the WOT did not provide instructions to operate the system in the emergency mode.
3.2. 1 Licensee Conclusions The licensee stated that the PMT was acceptable because Differential Pressure Indicator WMA-DPI-7 indicated above the TS minimum while the CRVS supply fan operated in the normal mode.
In this instance, the licensee stated they used Differential Pressure Indicator WMA-DPI-7 pressure indication to identify a potentially degraded control room boundary while the Supply Fan WMA-FN-518 operated and the Exhaust Fan WEA-FN-51 was off.
The licensee stated that any significant control room boundary leakages exhibited a low pressure indication during normal CRVS operation.
When the indicator signified a control room pressure below the TS minimum, the licensee stated that appropriate actions to determine system operability would be performed.
The licensee said that if the pressure indication was above the minimum requirement during normal operating mode with Exhaust Fan WEA-FN-51 off, then control room pressurization above the minimum requirement was certain in the emergency mode.
On January 26, 1995, the licensee demonstrated that the control room pressurized higher in the emergency pressurization mode of operation than in the normal mode of operation.
The licensee recorded Differential Pressure Indicator WMA-DPI-7 reading in the normal operating mode prior to performing the test.
The control room pressure was above the TS minimum of a positive 0. 125 inches wg.
The licensee performed Procedure 7.4,7.2.8,
"Control Room Ventilation Pressurization
'Flow Test,"
operating each emergency filter fan separately in the emergency mode and confirmed that the control room pressurized above the TS minimum requirement.
The licensee provided the inspector with the control room logs which indicated that the control room differential pressure greater than the TS minimum after
-12-Doo'r 4 gasket was repaired.
These logs were dated June 28, 1994, four days after the PMT was performed.
The logs noted these pressures were above the TS minimum while Supply Fan WMA-FN-51B operated for approximately four hours.
Based on this data, the licensee concluded that the emergency filtration system remained operable after the gasket replacement.
The licensee concurred that they did not document a formal PMT on Air Handling Unit WMA-AH-51B and noted the finding in corrective action Item 3 of PER 294-1002 (Section 4.4).
3.2.2 Inspector Conclusions The inspector concluded that the Door 4 PMT was not adequately documented.
The licensee did not document the baseline acceptance criteria based on differential pressure indication during the leak check on Door 4.'OT JR75
did not include instructions or acceptance criteria to verify that Differential Pressure Indicator WMA-DPI-7 was above the TS requirement during the leak check.
In addition, the WOT did not provide instructions to ensure that the exhaust fan was secured during the PMT.
Additionally, the inspector noted that the ability to identify a degraded control room boundary based on differential pressure indication was limited to the knowledge of the SE.
The control room operators were not able to identify a degraded control room envelope because the control room logs did not contain acceptance criteria for minimum differential pressure indication.
3.3 Leakin Emer enc Air Handlin Unit Access Door 6 Due to Missin Gasket On June 26, 1994, the SE identified that air was leaking from Door 6 of Air Handling Unit WMA-AH-51B because the door was missing its gasket.
The SE did not perform an operability assessment for a potentially degraded emergency filtration system.
The SE said that the system remained operable because the control room logs, dated June 28, 1994, suggested Differential Pressure Indicator WMA-DPI-7 was above the minimum requirement while Supply Fan WMA-FN-51B operated in the normal mode.
The SE initiated Priority 2 Work Request 94003344 with a need by date of July 1, 1994, to replace the gasket.
WOT LH85 01 provided instructions to repair the gasket.
On July 9, 1994, the SE realized Work Request 94003344 for the missing gasket on Door 6 was not completed; therefore, he initiated
'a second outage scope change request form to replace the gasket.
The second request indicated that the first outage scope change request was missing.
The second request suggested that the missing gasket caused the air handling unit to leak excessively and that work instructions and material were available to do the work.
The SE requested that the work be done during the outage to avoid entering an LCO during normal operations.
The form suggested that it would be easier to repair the door than do the test.
The outage manager annotated his approval to add the work to the outage on the outage scope change request form.
Sometime later, he and the SE decided to defer the task until after the outage because scheduling constraints prevented fitting the Door 6 gasket
-13-repairs into the outage schedule.
With the gasket missing on Door 6, the operability of the air handling unit was indeterminate while the plant changed modes on July 4, 25, and 27, 1994.
On September 9,
1994, with the plant at 100 percent power, the new control room CRVS SE walked down the CRVS and noted deficiencies on Air, Handling Unit WMA-AH-51B.
The new SE noted 20 deficiency tags on the system.
He characterized some of these deficiencies as "serious" while noting the missing Door 6 gasket as an example.
The SE did not initiate a
PER.
The SE did not consider the leakage problem severe enough to compromise operability and concluded the leak was adequately identified on the work requests.
On November 1,
1994, the licensee performed WOT LH85 01 to remove the damaged gasket on Door 6.
The WOT also provided instructions to cement a
new gasket on the door frame.
The instructions required that the cement cure for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
On November 2,
1994, the licensee performed the steps in WOT LH85 01 to check for leakage on Door 6.
The WOT required that operations start the fan and check for leaks.
The WOT noted that the test ran satisfactorily.
The WOT did not provide instructions to verify on Differential Pressure Indicator WMA-DPI-7 that control room pressure was above the TS surveillance minimum requirement during the test.
Instructions to ensure that Exhaust Fan WEA-FN-51 was secured were also not included in the WOT.
The WOT did not provide instructions to operate the emergency filtration system at the higher pressure of the emergency mode.
Therefore, the licensee did not verify gasket integrity at the higher pressure.
The PMT was inadequate to identify that the emergency filtration system was inoperable with the Door 3 gasket also missing as discussed in Section 3.4 below.
3.3. 1 Licensee Conclusions The licensee stated that prior to startup from the Refueling Outage 9, which occurred in July 1994, the major leaks on the Trains A and B of Emergency Filter Fan WMA-FN-54 units were fixed.
They verified, prior to startup, that both Trains A and B would pressurize the control room well above the TS limit (with Door 6 not fixed).
Therefore, the licensee concluded that they did not have to document the discrepancies on a
PER since these conditions were repaired prior to startup.
The licensee stated that they used another corrective action process, which was the work request process, to document the condition.
3.3.2 Inspector Conclusions The inspector was unable to determine if the emergency filtration system was operable following the identification of the degraded condition and after the PMT.
The licensee did not process a
PER nor did the licensee do a test to prove system operability in the emergency mode.
The licensee did not consider the impact of system leakages (if any),
because of emergency mode damper realignment.
The licensee did not test the system with Door 6 leakage 'to find
-14-out if any additional leakages, seen in the emergency mode, prevented successful control room pressurization.
3.4 Ino erable Emer enc Filtration S stem Due to Removin a Gasket from Air Handlin Unit WMA-AH-51B Enclosure Access Door 3 On October 26, 1994, control room personnel requested that mechanical maintenance dispatch CRVS trained craftsmen to investigate the operation of the CRVS, as the control room ambient temperature had increased over the past several days.
During this investigation, the craftsmen identified that nonsafety-related control room inlet registers were 80 percent plugged.
As a
result, registers were cleaned and the crew expanded the inspection to include the heater coils located inside the safety-related Air Handling Unit WHA-AH-51B.
After inspecting the heating coils, the craftsmen found that they could not close Door 3 of the air handling unit because the gasket appeared to be obstructing the door from closing.
The team notified their supervisor, who notified the control room, of the deficiency.
Control room personnel, apparently not attentive to the problem nor questioning as to how the problem occurred, directed the supervisor to have the obstruction removed and quickly close Door 3.
The craftsmen removed the obstructing portion of the gasket and used four people to force the door shut.
On November 3, 1994, the supervisor, who had requested the removal of the obstructing Door 3 gasket, directed a craftsman to initiate Priority 3 Work Request 94006022 to repair Door 3.
The work request identified repairs to the sheet metal binding the door operation and identified the missing gaskets The production SRO reviewed the work request to replace the missing gasket.
He concluded that the work was low priority and did not affect the operability of the CRVS.
He thought that the previous surveillance to verify the ability to pressurize the control room, successfully performed in July 1993, had been performed with the gasket missing.
On November 21, 1994, at 11:30 a.m.,
the licensee performed the 18-month surveillance test Procedure 7.4.7.2.8,
"Control Room Ventilation Pressurization Flow Test," for both emergency filtration system trains.
Emergency Filter Fan WHA-FN-54A met acceptance criteria of the TSs for pressurizing the control room and Emergency Filter Fan WHA-FN-54B did not.
The licensee declared Train B of the control room emergency filtration system inoperable and initiated PER 194-1002.
On November 22, 1994, the licensee determined that the absence of a gasket on Door 3 of Air Handling Unit WHA-AH-51B had resulted in the inability to pressurize the control room.
The licensee initiated WOT PY 53 01 to repair the Door 3 gasket, Also, on November 22, 1994, craftsmen received control room approval to begin WOT CR 70 Ol.
WOT CR 70 Ol provided instruction to install conduit and electrical cable for a modification associated with ASD recirculation pump installation.
A segment of work in the WOT required a breach of the control room ventilation boundary.
Between 12: 14 p.m.
and 1: 16 p,m.,
craftsmen
if,
-15-created two holes between the cable spreading room and the control room.
The holes were large enough to fit two 3-inch conduits.
These holes caused Trains A and B of the emergency filtration system to be inoperable because the emergency filtration fans could not maintain the control room pressurized above the minimum TS value as discussed below.
On November 23, 1994, at 3 a.m.; after the repair of the Door 3 gasket on Air Handling Unit WMA-AH-51B, the licensee reperformed the 18-month control room pressurization surveillance test to assess the operability of Train B.
Only Train B was retested and the test failed.
At 9:45 a.m.,
the licensee discovered that the two holes opened in the control room ventilation boundary rendered Train B of the control room emergency filtration system inoperable.
At 10:45 a.m., after resealing the holes and successfully performing the 18-month surveillance test, the licensee declared Train B of the emergency filtration system operable.
The licensee initiated PER 294-1018 to document the breach of the control room ventilation boundary.
This matter is discussed in detail in Section 3.5 of this report.
Through interviews and review of PER 294-1002, the inspector learned that the CRVS craftsmen, who were sent to Air Handling Unit WMA-AH-51B, discovered Door 3 of the air handling unit opened at a 45'ngle.
In the PER 294-1002 evaluation, the licensee characterized open Door 3 as being ajar.
The open door created a significant air flow path in the ventilation system boundary and would have prevented adequate control room pressurization if Train B of the CRVS had been called on to operate in the emergency mode.
Therefore, the open door rendered Train B of the emergency filtration system inoperable.
The length of time that Door 3 was open was indeterminate.
The licensee researched past work packages and interviewed craftsmen and contractors associated with maintenance on the air handling unit.
The licensee was unable to determine how long the door had been open.
During the interviews, the inspector discovered that the maintenance personnel occasionally opened the air handling unit doors to perform routine maintenance, such as changing the roll filters, without contacting the control room.
The inspector concluded that the air handling unit was apparently inoperable for an indeterminate period with Door 3 open.
The inspector concluded that the craftsmen did not realize the air handling unit was safety-related equipment.
The team did not contact the control room when they began inspecting the safety-related air handling unit.
Additionally, the inspector discovered that the craftsmen performed their investigation of the safety-related portion of the air handling unit without an approved work authorization.
As a result, the control room did not realize that the craftsmen were inspecting the safety-related air handling unit and the operators did not enter an LCO as required.
The inspector discovered that the craftsmen performed an unauthorized modification, which rendered the emergency filtration system inoperable, without control room personnel's knowledge.
After the craftsmen inspected the heating coils, the craftsmen discovered that they could not close Door 3 of the air handling unit because of bent hinges.
The craftsmen contacted their
-16-supervisor about their difficulty in closing the door.
The supervisor informed the control room operators that the door was open and could not be closed.
The control room operators were surprised that the door was open and directed the door be quickly closed.
The maintenance supervisor directed the craftsmen to remove the obstruction and close the door.
The supervisor never communicated to the control room that the Door 3 gasket had been removed.
As a result, the craftsmen performed an unauthorized modification by removing the obstructing portion of the gasket.
After the crew removed the gasket, four people were required to force the'oor shut.
After the operators later learned that the craftsmen experienced difficulties closing the door, they did not log that the door was open and that the unit had been inoperable; they did not enter a
LCO as required by TSs; they did not perform an operability assessment, and they did not initiate a
PER to evaluate the deficiency.
The licensee later learned that the removal of the gasket made the air handling unit inoperable without the control room staff's knowledge.
The inspector confirmed that miscommunication between maintenance personnel and missed opportunities during work request screening resulted in delays to identify and repair the inoperable fan unit.
Work Request 94006022 was not initiated until November 3, 1994, eight days after the gasket had been removed.
The work request was delayed because the CRVS supervisor and the work planner had miscommunicated on who would initiate the work request.
Additionally, the SRO who reviewed the work request did not identify that the missing gasket rendered the emergency filtration system inoperable.
The SRO concluded that the missing gasket did not affect the operability of the emergency filtration system.
He incorrectly assumed that the previous control room pressurization, that had been performed in July 1993, passed the test with the gasket missing.
The inspector concluded that the licensee's corrective action process was ineffective in identifying the inoperable emergency ventilation system and in promptly repairing the deficiency for this safety-related ventilation system.
3.4. 1 Licensee Conclusions The licensee agreed'hat the maintenance crew modified the air handling unit Door 3 gasket without the proper work authorization and design review.
The licensee added that they reported this finding in LER 94-019 under "Root Cause,"
page 3 of 7, and that this deficiency had been corrected as described by associated
"Further Corrective Action"
and
(same page of this LER).
3.4.2 Inspector Conclusions The inspector concluded that the licensee did not comply with TS 3.7.2 (a)
during the period between November 2 to November 22, 1994, in that the plant was in Operational Condition 1, with Train 8 of the control room emergency filtration system having been inoperable for more than seven days because of a missing gasket on Door 3.
The plant was not placed in hot or cold shutdown within the required times.
This is an apparent violation of TS 3.7.2 (a) (397/9434-01).
-17-3.5 Ino erable Trains A and B of the Control Room Emer enc Filtration S stem Due to Holes 0 ened in Control Room Floor The events which resulted in both trains of the emergency filtration system being inoper'able were described in the licensee's incident review. board (IRB)
minutes which were reviewed by the inspector.
On November 22, 1994, a crew initiated work under WOT CR70 01 to install cable trays and conduit in support of Plant Modification Record PMR/Basic Design Change 87-0244-OB for the new recirculation system ASD modification.
This task required that two 5-inch by 6-inch diameter plugs (for planned 3-inch conduits)
be opened through existing Penetration 5016.
Penetration 5016 was located in the bottom of control room Panel P682 which communicates with the cable spreading room..
The cable spreading room is located directly under the control room.
On November 23, 1994, the surveillance test was reperformed at 3 a.m.
Again Emergency Filter Fan WMA-FN-54B failed to pressurize the control room.
At 9:45 a.m., troubleshooting discovered that the two 3-inch holes in Panel P682 prevented the control room from being pressurized.
PER 294-1018 was initiated, the holes were plugged and the pressurization test was successfully reperformed by 10:45 a.m.
At approximately 3 p.m.
on November 23, 1994, the resident inspectors discussed this event with the plant manager.
The inspectors asked if he considered that both Trains A and B of the control room emergency filtration system had been inoperable.
He stated that management would review the event and make a determination.
Later that evening, management concluded that both Trains A and B of the emergency filtration system had been inoperable.
The licensee reported the inoperability of both Trains A and B to the NRC operations duty officer at 7:49 p.m.,
as required by 10 CFR 50.72.
Through interviews, the inspector discovered that the licensee exceeded TS 3.0.3 time requirements because the operators did not realize that both trains of the emergency filtration system were inoperable as a result of the open holes.
The licensee did not reperform the 18-month surveillance test on Train A of the emergency filtration system to verify that it was capable of pressurizing the control room.
The operators assumed that only the Train B of the emergency filtration system was inoperable after the test since the Train A had passed the surveillance test the day before.
The operators lacked a questioning attitude about operability of the emergency filtration system and did not verify operability of the redundant train.
As a'result, they did not enter TS 3.0.3 when both emergency filtration system trains were simultaneously inoperable.
Since the operators did not enter TS 3.0.3, they did not realize that they had exceeded the time requirement and, therefore, did not place the unit in the required conditions as described in TS 3.0.3.
The craftsme'n generally presented WOTs to the control room operators for approval to work prior to performing the job.
The operators assessed the WOT for impact on safety-related systems and tracked the inoperable equipment by
-18-initiating a TSs Inoperable/LCO/Offsite Dose Calculation Manual status sheet.
The status sheet included the inoperable equipment, a description of the problem, the time and date the equipment was declared inoperable, and the time and date the equipment was declared operable.
However, the inspector noted that the operators did not include a status sheet when WOT CR 70 Ol was approved to be worked, Through interviews, the inspector discovered the control room supervisor and the shift manager did not realize that the WOT would render the emergency ventilation system inoperable.
The licensee noted that WOT CR 70 Ol was different from normal work control packages.
The control room supervisor stated that the work order appeared incomplete.
The operators recollected that the craftsman only presented a fire barrier impairment form and a list of impairments with the work package.
The licensed operators did not recall noting an impact statement regarding the control room envelope on the WOT.
The WOT list d five precautions and limitations.
None of the precautions and limitations addressed an impact to the control room pressure boundary.
The licensed operators approved the work order task without questioning the completeness of the work order package.
The operators did not realize that opening the holes impacted emergency filtration system operability.
The licensee had a mind-set that previous work packages, which installed conduits penetrating the control room boundary, had been previously installed successfully.
The licensed operators approved the work task without entering an LCO.
Plant modifications required that a
PHR be generated.
The review process for the PHR, which included evaluation by the Plant Operations Committee for plant impact, required that a
CFR 50.59 safety evaluation be performed to evaluate the impact on the design basis of the plant and the impact on safety-related equipment.
The planners prepared detailed work instructions based on engineering information in the PMR.
For the ASD modification, the planners responsibilities included writing impact statements and initiating barrier impairment log sheets.
The inspector reviewed the procedures associated with the planning of WOT CR 70 Ol, which included the conduit installation.
The inspector confirmed that inadequate procedures used by the planners contributed to missed opportunities in identifying control room breaches during work planning.
Procedure 1.3.7D, Revision 5,
"Work Planning," provided vague planner guidance for including an impact statement.
The procedure instructed the planner to include an impact statement if the task involved any system which may impact safe, reliable operation of the plant.
This guidance relied on the planner's ability to recognize safety-related system impacts and incorporate impact statements as necessary.
The planner also initiated a barrier impairment log sheet identifying the impairments, per Procedure 1.3.57, Revision 2, "Barrier Impairment,"
when control room breaches were identified.
The procedure was inadequate because the procedure did not list the control room as a type of barrier to be considered for impairmen A seal control form, listing the seal requirements for the barrier being penetrated, was included in PMR 87-0244-01.
The planner's responsibility was to include impact statements in the work order instructions based on the sealing requirements listed on the seal form.
On June 24, 1993, the design engineer indicated on the seal control form the fire barrier and the air flow seal requirements.
The planner did not understand the purpose of the seal control form when preparing Work Order Task CR 70 01 when he received the PMR for processing.
The planner lacked training on the purpose of the seal control form and missed the fact that the conduit installation impacted the control room boundary.
As a result, the planner did not include an impact statement on the work order task.
The inspector reviewed the
CFR 50.59 safety evaluation for PMR 87-0244-1.
The safety evaluation focused on plant impact as a result of the completed design change and did not consider impact on safety-related equipment during the installation.
The safety evaluation indicated that there were no direct interactions with equipment or systems important to safety.
The individual who performed the evaluation noted that the installation process for the modification would not place the plant in an unsafe or unevaluated condition.
The evaluation did not consider the impact on the emergency ventilation system when the licensee opened the holes in the control room envelope to install the electrical conduits.
The
CFR 50.59 review was narrowly focused and did not assess impact on safety-related equipment during the installation phase.
3.5. 1 Licensee Conclusions The licensee attributed the inadequate evaluation to deficient procedures used for guidance in evaluating plant impact while installing plant modifications.
The licensee determined that older design change packages needed improvement in assessing impact on safety-related equipment during modification installation'.
Procedure 1.4. 1, "Plant Modifications," did not include guidance on installation, testing, and operational considerations.
3.5,2 Inspector Conclusions The inspector concluded that the licensee did not conform to TS 3.0.3 while in operational Condition 1 during the following period:
From November 22, 1994, at approximately 1: 16 p.m. to November 23, 1994, 10:45 a.m.
both trains of the control room emergency filtration system were inoperable for approximately 21 hours2.430556e-4 days <br />0.00583 hours <br />3.472222e-5 weeks <br />7.9905e-6 months <br /> due to opened holes through the control room ventilation boundary.
The licensee did not take the prescribed actions of TS 3.0.3 to take action within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> to place the plant in startup within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and hot shutdown within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
This is an apparent violation of TS 3.0.3 (397/9434-03).
-20-
LICENSEE ROOT CAUSE DETERMINATION AND CORRECTIVE ACTION 4. 1 LER 50-397 94-012:
Emer enc Filter Unit Rendered Ino erable as a Result of Leakin Delu e Isolation Valve During the root cause evaluation, the licensee identified missed opportunities for earlier detection of the inoperable charcoal filter unit because they did not recognize the impact that the leaking deluge spray valve had on the emergency filter unit.
The first was that the system engineer relied on the design overflow feature to drain the leakage from the isolation valve until it was placed in a 12-week rolling maintenance schedule.
Second, the production scheduling shift manager, who reviewed the associated work request for operability impact, did not recognize the potential for leakage to exceed the capacity of the overflow line and enter the filter units; thus, he assigned it a low priority and put it on the next rolling maintenance schedule.
Finally, the operator did not question the effect that the water draining from the filter unit bottom drain might have on the associated charcoal filter.
Additionally, the licensee attributed inadequate communication as a
contributing cause.
The licensee identified that after the equipment operator informed the SSS that the leakage was rectified, the SSS erroneously concluded that the drainage had been stopped from the deluge station drains and not from the filter units bottom drains.
The licensee identified that operations lacked communication because operations did not inform system engineering of the water draining from the filter unit bottom drains.
The licensee performed the following corrective actions as a result of the leaking deluge valve event:
Operations management conducted a one-on-one discussion with the equipment operator and the SSS who investigated the reported leakage to emphasize the lessons learned from this event and issued night orders to the operations staff to emphasize the missed opportunity for earlier detection of water in the filter unit.
System engineering management discussed lessons learned from this event with the responsible system engineer.
~
Appropriate procedures were revised to specify both upstream and downstream deluge supply isolation valves as normally closed, and a
3/4-inch deluge supply drain valve as normally open for both control room emergency filter units.
Given the revised line-ups, these procedures included appropriate guidance for manual deluge system actuation and restoratio ~
The LER was included in the operations and engineering industry events training programs.
The work control staff also attended.
The training emphasized the importance of determining the potential impact of apparent low priority deficiencies on safety-related equipment.
The inspector noted that the licensee did not include training on identifying and initiating a PER to perform operability assessments on degraded safety-related equipment.
4.2 LER 50-397 94-019:
Filtration S stem Rendered Ino erable as a Result of a Missin Gasket on Air Handlin Unit WMA-AH-51B The licensee determined that the root cause of this event was that the mechanical maintenance supervisor allowed the design of Air Handling Unit WMA-AH-51B to be modified without proper authorization, design reviews or controls.
The licensee added that, based on interviews conducted, the incident was isolated and that activities involving alteration of plant equipment without proper documentation and authorization were not routine.
The licensee performed the following corrective actions as a result of the removed gasket event.
The maintenance manager counseled the mechanical maintenance supervisor on the need for the proper work authorization, design reviews, and controls before proceeding with work activities that alter the plant configuration (including removal of gaskets).
The manager also emphasized that he expected his supervisors to promptly identify and document plant problems.
The maintenance manager discussed this event with each of his maintenance shops.
The manager pointed out the following:
1)
The need to promptly and accurately document plant problems to include what was done to correct the problem and any unusual observations or deviations from the routine during the course of associated work, 2)
The requirement to obtain approval prior to changing the configuration of the plant; and, 3)
The importance of pressurization boundaries.
4.3 LER 397 94-021:
0 en Holes in Control Room Floor The licensee attributed the root cause of the event to inadequate procedures.
The licensee noted that Procedure 1.3.7D, Revision 5,
"Work Planning," did not
.sufficiently guide the planner in identifying that his work could affect equipment related to safety.
The licensee identified that the following
P,
-22-procedures contributed to the missed impact on the control room boundary and needed revision:
Procedure 1.3.7D did not contain sufficient guidance to ensure the planner identified that a credited function would be affected by planned work on a barrier and of the potential need for additional actions.
In turn, if this guidance regarding barrier impairment were provided, the planner would be able to better communicate these needs to the production scheduling shift manager whose job functions require senior reactor operator qualifications.
With this information, the production shift manager would be in a better position to properly evaluate the impact on, credited functions.
Procedure 1.3.57, "Barrier Impairment,"
was provided to establish a
method for tracking impairment of barriers and for evaluating the impact on affected safety system operability.
The barrier involved in this event deals with radiation ingress to the control room.
This procedure listed two barriers to mitigate a radiation release event:
secondary containment and main steam tunnel penetrations.
It did not provide clear guidance on control room envelope barriers.
Procedure 15.4.5,
"Penetration Fire Seal Haintenance Inspection,"
provided instructions for installation and repair of fire-rated and nonfire-rated penetration seals.
Additionally, this procedure contained the form, and controls the seal requirements, used by engineering to control work on penetrations.
This procedure required enhancement in that it needed to explain the meaning of the seal requirements listed on the form and needed to reference Procedure 1.3.57 to ensure impairments to credited barriers were considered, The licensee also identified that the following procedures did not advise the user to review Procedure 1.3.57 to determine if planned work would impair a
credited barrier:
Procedure 1,3. 10, "Fire Protection System Program," which provided compensatory measures in the event of a fire protection system barrier or component impairment.
Procedure 10.25.57,
"Electrical Raceway Installation," which provided installation and inspection criteria for electrical raceway and supports in seismic Category I and II areas.
The licensee performed the following corrective actions as a result of the holes opened in the control room floor event:
Procedure 15.4.5 was revised to explain the meaning of the seal requirements listed on the Seal Control Form.
This procedure was also revised to reference Procedure 1.3.57 to help users determine if seal work could also impair credited barrier Procedure 1.3.7D was revised to help planners identify that a credited function could be affected by planned work and that the need for the following may apply:
1)
Additional specialized help may be required to evaluate impact on credited barriers, 2)
Use of barrier impairment log sheets, and 3)
The work order impact statement needs to be completed to identify the critical work to the production scheduling shift manager so work can be appropriately authorized.
~
Procedure 1.3.70 was revised to emphasize the need for the planners to identify barrier impairments in the Impact statement.
~
Operations training on barrier impairments would be presented to include a review of Operations Department responsibilities associated with managing impairments and the applicable procedure changes made as a
result of this training.
The training was anticipated to be completed by March 1,1995.
The engineering staff support training department would conduct training for appropriate engineering staff to review the applicability of Procedure 1.3.57.
Work planning personnel will also attend this training.
The training was anticipated to be completed by Harch 24, 1995.
Procedure 1.3.57 was revised to include the control room envelope as a
part of the barrier impairment evaluation criteria.
This procedure was clarified to help the user understand its applicability.
Training sessions were conducted with engineering, maintenance, operations, work planning, quality assessment, and the plant contractor to ensure personnel understanding of the procedure revisions implemented to avoid a recurrence of this event.
Night orders were issued to operations crew to discuss how cutting the holes in Penetration 5016 impacted the ability of the CRVS system to pressurize the control room.
Corrective actions addressing this concern were discussed and it was emphasized to the crews that until corrective actions were fully implemented, extra care must be taken in authorizing seal removal and barrier penetration.
It was pointed out that, as a
minimum, these authorizations should be preceded by contacting the approp'riate Technical Services engineer and discussing the potential impact and compensating methods require I
THOROUGHNESS IN LICENSEE ROOT CAUSE DETERMINATION The inspector reviewed IRB minutes, PERs, and LERs to determine whether the licensee adequately evaluated all three events for root cause determination.
The licensee generally performed an acceptable review of each event.
However, the inspector discovered instances where the licensee could have been more thorough and the inspector noted several missed opportunities to have identified the problems earlier as discussed. in this section and Section
below.
With respect to LER 94-12, the licensee did not research the operability of the Train A of the CRVS while Emergency Filter Unit WMA-FU-54B was inoperable.
In the LER the licensee noted that the Train A of Emergency Filter Unit WMA-FU-54A was installed for redundant control room filtering capability.
However, LCO status sheets indicated that Emergency Filter Fan WMA-FN-54A was simultaneously inoperable between 8: 19 p.m.
on June 19, 1994; and 11:50 p.m.
on June 21, 1994; and between 2: 10 a.m, on June 22, 1994, and 3:56 p.m.
on June 23, 1994; for Supply Fan WMA-FN-51A door gasket seal replacement and conductor replacement, respectively.
Additionally, the licensee did not convene an IRB to discuss the leaking deluge valve event.
The PER analysis did not discuss the operability of the redundant Train A of the CRVS during the period Emergency Filter Unit,WMA-FU-54B had been declared inoperable.
The inspector noted that a corrective action of LER 94-12 was to include the LER in industry events training and emphasize the importance of determining the potential impact of apparent low priority deficiencies on safety-related equipment.
However, a contributing factor in the failure to identify that Train B of the control room emergency filtration system was inoperable (as reported in LER 94-19)
was that the SRO reviews did not identify or question the potential impact of the low priority work request to replace the missing gasket.
LER 94-19 did not address the apparent ineffectiveness of this corrective action, With respect to LER 94-19, the licensee did not identify that the maintenance crew discovered Door 3 of Air Handling Unit WMA-AH-51B open on October 26, 1994.
The IRB minutes, dated November 29, 1994, indicated that the maintenance team opened Door 3.
Through interviews, the resident inspector ascertained that the maintenance team discovered Door 3 open.
The IRB did not address the length of time the unit was inoperable.
Later in the PER evaluation, the licensee included that the craftsmen had found Door 3 open.
The licensee stated that the LER did not include the fact the door was discovered open because the validity of the evidence was inconclusive.
Also in reference to LER 94-19, the inspector noted that the licensee's corrective actions did not address the involvement and contribution that the
~control room staff had in this event.
The inspector found that the control room staff recognized that opening Air Handling Unit WMA-AH-51B rendered the Train B of the emergency filtration system inoperable and requested the unit be returned to service immediately.
However, the control room staff did not
-25-log that maintenance personnel had opened Air Handling Unit WMA-AH-518 and, thus, made the Train 8 inoperable.
Additionally, the control room staff did not initiate a
PER to document this issue.
With respect to LER 94-21, the licensee stated that recent changes.
had been made to Procedure 1.4. 1, "Plant Modifications," that required design change packages to include guidance on installation, testing, and operational considerations and that
CFR 50.59 evaluations in design change packages are now more rigorous.
The inspector found that this procedural change had been implemented.
However, the inspector found that the licensee had decided that for modifications which had their
CFR 50.59 evaluations done prior to the implementation of the procedure change, a reassessment of the
CFR 50.59 evaluation would not be reperformed.
The design work for the ASD modification of this LER was initiated in 1987 and the
CFR 50.59 evaluation for the modification did not include consideration for impact during its implementation.
The inspector considers that events similar to the event reported in LER 94-21 may recur if the licensee does not reassess the impact to safety of the implementation of modification packages that were generated prior to the procedure change.
INEFFECTIVE LICENSEE CORRECTIVE ACTION PROCESSES The review of licensee actions relative to numerous problems with the CRVS revealed that there were several missed opportunities to identify and correct conditions which rendered the emergency filtration system inoperable.
The inspector concluded that the licensee did not adequately identify and assess safety-related emergency filtration system operability during the following periods:
On Harch 31, 1994, when the licensee failed to initiate a
PER and perform an operability assessment for a degraded deluge isolation valve which eventually rendered the charcoal filter unit inoperable.
On Hay 31, 1994, when the licensee failed to initiate a PER and perform an operability assessment for the inoperable Emergency Filter Unit WHA-FU-548, after water was discovered draining from the filter unit drain.
On April 5, 1994, when the licensee fail'ed to initiate a
PER and perform an operability assessment for the degraded safety-related Air Handling Unit WHA-AH-518 Door 4 blown seal.
On June 23, 1994, when the licensee failed to initiate a
PER and perform an operability assessment for degraded Air Handling Unit WHA-AH-518 when the Door 6 gasket was discovered missing.
On October 26, 1994, when the licensee failed to initiate a
PER to perform an operability assessment for the inoperable safety-related Air Handling Unit WHA-AH-518 with Door 3 gasket missing and bent hinge ~
On October 26, 1994, when the licensee failed to initiate a
PER to perform an operability assessment to determine the cause of the condition and determine corrective action to preclude recurrence when Air Handling Unit WMA-AH-51B Door 3 was discovered open.
The inspector reviewed licensee Procedure 1.3. 12 "Problem Evaluation Request (PER),"
and determined that it was potentially inadequate in that it was unclear whether there was any specific requirement for when a
PER was to be issued.
This may have contributed to the failure to initiate PERs in the examples noted above.
The inspector concluded that the above noted examples represented a failure of established measures to ensure that conditions adverse to quality were promptly identified and corrected and was an apparent violation of Criterion XVI of Appendix B to
CFR Part 50 (397/9434-04).
PREVIOUS REVIEW OF RADIOLOGICAL CONSE(UENCES NRC Inspection Report 50-397/95-01 reviewed the licensee's evaluation of the potential radiological consequences as a result of an inoperable emergency filtration system for selected assumed accidents.
Between May 31 and June 23, 1994, Emergency Filter Unit WMA-FU-548 was unable to remove radioactive iodine because of a wetted charcoal filter.
The highest probability for a radiological release was between May 5, 1994, and June 13, 1994, when radioactive fuel movement occurred intermittently.
LCO status sheets indicated that Train A of the emergency filtration system remained operable.
The licensee calculated the consequences of a radiological release for a hypothetical fuel bundle drop.
The licensee calculated the whole body 30-day integrated dose to the control room operators would be 2.6 E-04 REM and the 30-day integrated thyroid dose would be approximately 2.7 E-03 REN assuming that the accident occurred 35 days after shutdown.
The inspection report concluded that the doses were very low.
The inspector concluded that during fuel movement, Train A of the control room emergency filtration system was operable and was capable of removing radioactive iodine.
Prior to the April 26, 1994, shutdown, when Deluge Isolation Valve FP-V-WMA/21 began leaking on March 30 and when Door 4 of Air Handling Unit WMA-AH-51B was identified leaking, the licensee calculated the 30-day integrated thyroid dose would be 8.6 REN.
This was based on the assumptions of no control room air filtration and primary and secondary containment leak rate based on the plant's eighth refueling outage local leak rate data.
Therefore, the licensee concluded that a significant, but not an overexposure, thyroid radiation dose could have been received by the control room personnel while emergency filtration unit was inoperable and the plant at 100 percent power with all other redundant safety systems also inoperable and not availabl ~
~
-27-During inspections, the inspectors were provided no conclusions by the licensee on the potential thyroid dose based on the ninth refueling outage local leak rate data or based on a design basis leak rate.
CONCLUSIONS The licensee did not evaluate system design for potential equipment degradation and missed opportunities in assessing degraded safety-related or important to safety equipment for operability on numerous occasions.
The apparent violations identified and weaknesses in utilization of corrective action processes and design modification implementation appear to represent a
breakdown in activities associated with the design, maintenance, testing and operation of the control room emergency filtration system and the licensee's corrective action progra ATTACHMENT
PERSONS CONTACTED 1. 1 Licensee Personnel
- J
- H
+*R.
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+ P.
J.
+ J.
R.
- J
- V
- A
+ K.
- J
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+ H.
- W
+ C.
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+ J.
+*D.
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+ N.
Albers, Radiation Protection Manager Baird, Shift Manager Barbee, System Engineering Manager Bekhazi, Project Engineer Bemis, Manager, Regulatory and Industry Affairs Boesch, Maintenance Acting Hanger
'urn, Director, Engineering Conserriere, Shift Manager Gearhart, guality Assurance Director Harris, Maintenance Specialist Langdon, Assistant Operations Hanager Lewis, Licensing Engineer Huth, Plant Assessments Manager Parrish, Vice President Nuclear Operations Pedro, Licensing Engineer Reddemann, Technical Service Division Manager Sawyer, Day Shift Manager Schwarz, Operations Manager Smith, Director, guality Assurance Swailes, Plant Manager Swank, Licensing Manager Taylor, Shift Manager Weimer, Training Specialist Zimmerman, BOP System Engineering Supervisor
- Attended the exit meeting on January 26, 1995.
+ Attended the exit teleconference meeting on february 15, 1995 1.2 NRC Personnel
+*S.
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+*R.
+ D,
+ J.
+ J.
Campbell, Resident Inspector, Arkansas Nuclear One Kirsch, Chief, Project Branch E
Barr, Senior Resident Inspector Proulx, Resident Inspector Dyer, Deputy Director, Division of Reactor Projects Clifford, Project Manager, NRR The personnel identified above attended the exit meetings.
In addition to these personnel, the inspectors contacted other personnel during this inspection perio EXIT MEETINGS The inspector conducted an exit meeting on January 26, 1995 and a final exit teleconference on February 15, 1995.
During this meeting, the inspectors reviewed the scope and findings of the inspection.
The licensee did not identify as proprietary any information provided to, or reviewed by, the inspector.