IR 05000251/1988025
| ML17345A458 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 09/27/1988 |
| From: | Kahle J, Stoddart P NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML17345A456 | List: |
| References | |
| 50-251-88-25, NUDOCS 8810130097 | |
| Download: ML17345A458 (23) | |
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Report No.:
50-251/88-25 UNITED STATES NUCLEAR REGULATORY COMMISSION
REGION II
101 MARIETTASTREET, N.W.
ATLANTA,GEORGIA 30323 gp g '( nod Licensee:
Florida Power and Light Company 9250 West Flagler Street Hiami, FL 33102 Docket No.:
50-251 Facility Name:
Turkey Point
License No.:
DPR-41 Inspection Conducted:
August 16-25, 1988 I
f Inspector:
M/r.
W-P. Sto art
!
Team Members:
R.
tcher, Senior, Resident Inspector G. Schnebli, Resident Inspector T.,
cElhinney, Resident Inspector I
/
Approved by:
J.
B Kahle, Section Chief DiII'sion of Radiation Safety and Safeguards Da e Signe Date Signed SUMMARY Scope:
This special, announced inspection was conducted in the areas of root cause determination and radiological aspects of the radioactive liquid spill of August 15-16, 1988.
Results:
One violation was identified:
Inadequate procedure for repair and re-installation of Spent Fuel Pool Pump 4A.
Licensee weaknesses identified during this inspection included:
The inability of. the operating and maintenance staff to identify the common root cause of six essentially identical major failures of SFP recirculating pump 4A within the six year period of 1975 to 1981.
Weak operating or maintenance practices as illustrated by the failure to legibly mark pushbuttons controlling operation of SFP recirculating pump 4A.
Weak maintenance and radiation control practices as illustrated by the failure to recognize and remedy the long-standing recurrent problems of radioactive or potentially radioactive water backing-up from Auxiliary Building floor drains.
8810130097 880927 PDR ADQCN 05000251
PNU
Weak operating and radiochemistry control practices as illustrated by failure to identify and remedy the cyclic backup of Co-60 contamination to SFP water.
Licensee strengths identified during this inspection included:
The commitment by FPICL corporate management prior to this event, of a strong management team with specific.direction to identify and resolve all long-standing problems or deficiencies in plant operations.
The prompt formation -of-a technically competent an'd enthusiastic Event Response Team (ERT).
Rapid and effective response of health physics personnel in controlling the spread of contamination resulting from the even )
h
REPORT 'DETAILS Persons Contacted Licensee Employees
- T. Abbatiello, Supervisor, Performance Monitoring, Quality Assurance (QA)
- M. Bladow, Superintendent, QA
- J. Cross, Plant Manager
- A. Cummings, Plant Security Supervisor
- R. Hart, Acting Regulation and Compliance Supervisor P.
Hughes, Health Physics Supervisor
- J. Kappes, Maintenance Superintendent
- R. Mende, Operations Supervisor
- J.
Odom, Site Vice President H. Southworth, Superintendent, Technical Services R. Steinke, Acting Chemistry Supervisor
- H. Young, Project Site Manager Other licensee employees contacted during this inspection included engineers, technicians, and administrative personnel.
Nuclear Regulatory Commission R. Butcher, Senior Resident Inspector T. McElhinney, Resident Inspector G. Schnebli, Resident Inspector
- Attended exit interview Notification of Unusual Event (NOUE) (93702)
At 12:55 a.m.
(EDT)
on August 16, 1988, with Unit 4 in Mode 3, the licensee declared an Unusual Event due to a spill of radioactive water from the Unit 4 Spent Fuel Pool (SFP).
The NRC (HQ) Duty Officer was notified at 1: 18 a.m.,
August 16, 1988.
The SFP coolin'g system, where the spill originated, and the circumstances leading up to the event are discussed below.
No violations or deviations were identified.
System Description (93702)
The SFP cooling system included three SFP cooling water circulation pumps.
Pump
A was an Ingersoll-Rand centrifugal pump and-was designated as the alternate pump.
Pump
.4B was a Goulds centrifugal pump'nd was designated as the primary circulation pump.
Each pump was rated at 2300 gallons per minute (GPM) at 125 feet Total Discharge Head.
The system was also
provided with an emergency SFP cooling water recirculation pump (Pump 4C),
which was a Worthington centrifugal pump.
Pump 4C was designed to be used only when both 4A and 4B were out-of-service.
Through valved connections, all three pumps took suction from the SFP, discharged to the SFP heat exchanger and provided the pressure necessary to return the water to the SFP.
When deemed necessary to maintain water clarity and purity, 5% of the pump flow could be diverted to a filter-demineralizer train and then returned to the SFP.
All three pumps were located in the Unit 4 SFP Heat Exchanger Room and were locally controll'ed.
No violations or deviations were identified.
h Chronology of the Event (93702)
On August ll, 1988, a construction contractor began work on the 4B SFP cooling circulation pump control and power systems to implement Plant Change/Hodification (PC/M)85-148, which required 4B pump to be taken out-of-service.
The emergency SFP cooling circulation pump 4C was placed in service to establish a cooling loop.
Although the 4A pump was available for use, the emergency pump was placed in service due to the poor performance history of the 4A pump.
On August 12, 1988, a 480 volt load center ground fault caused the 4C emergency SFP cooling circulation pump motor to fail.
The 4A pump was placed in service later that day.
On August 13, 1988, a construction supervisor reported that the 4A pump was excessively noisy.
On August 15, 1988, construction personnel working in the SFP heat exchanger room noticed that the 4A pump was
"extremely" noisy, and this fact was noted by the construction foreman.
Also, on August 15, 1988, the construction foreman noted, but did not report that the pump bearing oiler, which was mounted on the side of the pump shaft bearing housing, was tilted to one side.
The oiler was placed in a
vertical position by construction personnel, who noted that the oiler was
"finger loose."
Later.,
on the night of August 15, 1988, the -construction crew stopped work and exited the heat exchanger room at approximately 10: 10 p.m.,
and Health Physics (HP)
personnel locked the door.
At-10: 10 p.m., the 4A pump was still running, no water was seen on the floor, and none of the construction workers were found to be contaminated when they left the Radiation Control Area (RCA).
The Unit 4 Reactor Control Operator (RCO) logged a
SFP low level alarm at 12:03 a.m.,
on August 16, 1988.
At approximately the same time, Auxiliary Building personnel reported unidentified water backing up from floor drains and water coming from the Unit 4 SFP heat exchanger room.
Personnel at the RCA control point reported workers exiting the Auxiliary Building and passing near the Unit 4 SFP heat exchanger room door had contaminated shoes.
HP was requested to investigate.
At approximately 12: 10 a.m.,
the HP Supervisor reported that the water appeared to be'oming over the sill of the SFP heat exchanger room.
A Nuclear Operator (NO) was dispatched to the area to investigate furthe The NO and a'P technician entered the SFP heat exchanger room and saw water coming from the 4A SFP cooling circulation pump casing vent valve (Valve 4-915A).
The NO attempted to stop the leak by closing the vent valve; however, only two turns of the valve handle could be completed before the valve stem jam nut prevented further closure by hitting against the valve bonnet.
This action did not stop the leak; therefore, the NO exited the room to obtain a valve wrench to close the pump suction valve.
At the same time, the NO noticed that the pump shaft was not turning, but the motor was still running.
At approximately 12:25 a.m.,
the suction valve was closed and the leak stopped.
A second NO in the-room tried to stop the 4A SFP cooling pump motor using local controls; however, the motor would not stop.
A mechanical maintenance supervisor then entered the room and noticed that the 4-915A valve stem extension indicated that the valve was still partially open.
The stem jam nut was backed off with a wrench and the valve was closed an additional 3 to 4 turns.
The motor was still operating at this time and another attempt was made to stop it using the local controller.
This time the motor stopped.
It was discovered that the wrong pushbuttons were being depressed due, in part, to the pushbuttons being unlabeled except for light pencil 'markings.
At approximately 4:00 a.m.,
the mechanical maintenance supervisor noticed that the pump bearing oiler reservoir was on the floor'and that the oiler elbow was tilted down.
~
No violations or deviations were identified.
Licensee Investigation of Event (93702)
On August 16, 1988, the licensee formed an Event Response Team (ERT) to investigate and analyze the event, identify root causes, establish corrective actions, and provide recommendations to prevent recurrence of similar events.
The ERT identified three root cause issues of this event which included:
Valve 4-915A in the open position; Auxiliary Building floor drain system not functioning properly; and the 4A SFP cooling pump failure.
The first issue concerning the opening of valve 4-915A was still open as of the date of this report.
The licensee was investigating possibilities which included:
(1) The valve vibrated open due to the pump failure or (2) the valve was opened by personnel.
An independe'nt laboratory had been contracted to perform vibration tests on the v'alve to explore the first possibility further.
The initial test results indicated that the valve vibrated open at vibration levels expected to have occurred during this.
event.
The second issue concerned the SFP heat exchanger room floor drains.
The ERT review of the drain system design revealed that any leak less than
GPH should have been handled and sent to the Waste Hold-Up Tanks.
The maximum flowrate from 4-915A was calculated to be
GPN.
Blockage in the drain system was suspected, based on backup flooding of drains in the.
auxiliary building, and the relatively small increase in the floor drain waste holdup tank level.
Another factor affecting the drain system
capability was that Tygon tubing had been stuffed into a drain in. order to direct a
known leak to the drain system.
This reduced the input capability of the drain system.
The licensee was continuing the investigation of the adequacy of the floor drain system.
The third issue concerned the 4A SFP cooling pump failure.
Visual examination of the pump components indicated that the cause of the failure was insufficient lubrication.
The as-found condition of the oiler reservoir and the p'ipe connection indicated that the bearing housing oil had drained to a level below the oiler rings.
The as-found oil level was measured and approximately 200 ml was collected.
Refilling the housing to the proper level required approximately 2000 ml.
A review of the oiler configuration revealed that the oiler reservoir was not properly mounted with respect to the bearing housing.
The oiler was designed to act as a
constant-level feeder to keep the bearing sufficiently lubricated.
However, the oiler reservoir was mounted too low.
This resulted in the oiler failing to maintain adequate oil in the bearing sump for proper bearing lubrication.
Therefore, the pump bearing housing was low in oil when it was placed in service on August 12, 1988.
The pump and housing assembly were disassembled and inspected.
The following observati.ons were noted:
(1) the shaft had sheared adjacent to the radial bearing on the impeller side due to fatigue; (2) the radial and thrust bearings exhibited damage due to overheating and wear; and (3) the impeller hub and side indicated significant wear due to rubbing on the casing.
The maintenance history for the 4A SFP cooli.ng pump was reviewed and revealed several failures which are listed below:
Date
.
4/12/75 4/29/75 5/17/75 5/22/78 9/11/78 6/3/81 Failure Seized, impeller galled, seals destroyed, shaft sheared Seized,'earing housing gall ed Seized, impeller galled, shaft sheared Shaft shear Seized, seals destroyed Unknown...required overhaul Mechanism Radial bearing failure Thrust bearing failure Radial bearing failure Unknown Radial bearing failure Unknown Cause Overheated bearing Overheated bearing Overheated bearing Unknown Insufficient 1 ubri ca'ti on Unknown The poor performance history of the Ingersall-Rand pump eventually led to the pump being classified as the standby pump.
The inspector expressed a
concern to the licensee management regarding the 4A SFP cooling pump failure history.
The corrective actions to the previous failures
apparently were not adequate and therefore, the pump was used only when the 4B and emergency SFP cooling pumps were not available.
The issue of Operations
"working around" known maintenance problems was identified by the NRC several years ago (ref.
SALP Report 86-27)
and was confirmed by FP&L's Independent Management Appraisal (IMA) conducted in early 1988.
The licensee had responded to the IMA recommendations on August 15, 1988, and was implementing corrective actions.
CFR 50, Appendix B, Criterion V, as implemented by the approved Florida Power and Light Company Topical
'uality Assurance Report (FPLTQAR)
1-76A, Revision 10, and by Topical Quality Requirement (TQR)
5.0.
Revisi'on 7,
requires that activities affecting quality shall be prescribed by documented instructions, procedures, or drawings of a type appropriate to the circumstances and shall be accomplished in accordance with these instructions, procedures, or drawings.
Contrary to the above, Maintenance Procedure (MP) 3507.2 entitled, Spent Fuel Pit Pump-Disassembly, Repair and Assembly (Ingersoll Rand), revision dated November 4, 1986, did not provide adequate instruction for installation of the 4A SFP cooling pump, as evidenced by the constant level oiler being improperly mounted.
This resulted in an inadequate lubricating oil supply for the pump bearings.
This item will be tracked as Violation 50-251/88-25-01.
(Opened) -VIO 50-251/88-25-01:
Inadequate maintenance procedure did not provide adequate instructions on drawings for the assembly and installation of'he 4A SFP cooling pump, as evidenced by the improper mounting of the constant level oiler.
One violation (50-251/88-25-01)
was identified.
No deviations were identified.
Radiological Aspects of the Radioactive Water Spill of August 16, 1988 (93702)
The initial licensee report specified the..loss of approximately 2,833 gallons of water from the Unit 4 SFP and estimated activity at 3.7 E-02 uCi/ml, based on a
sample of SFP,water taken on August 11, 1988.
At 3: 18 a.m.
EDT, the estimate was revised to 3,166 gallons and radioactivity level at 6.41 E-02 uCi/ml Co-60 and 7.95 E-04 uCi/ml Cs-137.
A RII inspector was dispatched to the site Tuesday afternoon and was on site at 6:30 a.m.
Wednesday morning, August 17, 1988.
Upon arriving at the site, the inspector was briefed on current conditions relative to the spill by licensee representatives and had an escorted tour of the site areas involved.
The inspector.
was also briefed by the resident inspectors, attended a meeting of the ERT formed by the licensee to investigate and determine the root cause, and discussed the Quality Assurance Department investigation, which was investigating the event independently of the ERT, with.cognizant licensee staf i i
The spill'as largely contained within the. licensee's RCA.
Based on observation of the affected area, licensee Health Physics survey maps of the contaminated area, results of licensee preliminary decontamination efforts and
.projected decontamination efforts, and on samples of subsurface gravel (analyzed by the licensee to determine degree of penetration of water into the gravel fill affected by the spill) the inspector estimated that no more than 100 gallons'f the spilled material had escaped directly into the plant storm drain system.
Based on analysis of storm drain samples, the licensee's tentative estimate of discharge via the plant storm drain system was 8 gallons (per unoffical estimate dated August 23, 1988, based on telephone conversation between inspector and plant personnel).
The radioactivity level of the spilled water was initially reported as 6.7 E-02 uCi/ml of Cobalt-60 and 7.9 E-04 uCi/ml of Cesium-137.
The Cobalt-60 level was subsequently revised downward to 2.3 E-02 uCi/ml due to an incorrect geometry factor entered in error in the computer program.
Based on the licensee's corrected concentration value and estimated volume released to the storm drain, the total activity released to the cooling canal (which was confined to licensee property)
was estimated at 7.00 E-04 Ci.
Samples of water from the cooling canal, taken downstream of the probable point of discharge by both the licensee and the State of
'lorida, contained no radioactive material above the Minimum Detectable Activity.
As of the end date of the inspection, the licensee had not revised the total volume of the spill from the original (August 16) figure of 3,166 gallons.
The value was calculated on the measured change in SFP-water level on the night of August 15-16.
Of the 3,166 gallons involved, an estimated 1,100 gallons was retained by the heat exchanger pump room's diked floor and about 750 gallons went to the Auxiliary Building floor drain system, leaviwg approximately 1,316 gallons postulated to have spilled over the room's exit threshold.
Assuming 8 to 10 gallons entered the storm drain system, approximately 1,300 gallons flowed over an asphalted area, across.a heavy-duty asphalt road, and into an area of gravel fill lying between the asphalt road bed and'he foundation of the protected area security fence and sloping from the road to the fence foundation.
The foundation of the security fence was of continuously-poured concrete construction.
The foundation protruded above the gravel fill by about 1.0 to 1.5 feet and appeared to provide a substantial barrier preventing any rapid subsurface movement of the contaminated water in the direction of the cooling canal, the nearest probable point of entry into a surface water system.
As of the end date of the inspection, the licensee had initiated a
decontamination project involving removal of 4 to 6 inches of gravel from the sloping area between the road and the security.fence and had removed gravel from a small area adjoinfng the security fence to a depth of about
three feet.
Radioactive material attributable to the spill was found at that depth but had apparently been diluted by water from heavy rains occurring both prior to, and subsequent to, the time of the event.
As of the end date of the inspection, work was still in progress in remediation of the contaminated gravel zone, in defining the contaminated area and volume, and in assessing possible local groundwater movement patterns.
As of August 20, 1988, a
licensee representative stated that about 40 55-gallon drums of gravel had been removed and packaged for offsite disposal and estimated that 300 to 400 55-gallon drums of material would be involved by the end of the decontamination effort.
It was noted that the actual volume would be dependent on the spread or transport of the contaminant within the gravel and soil underlying the affected area and was not to be considered a firm value.
Licensee decontamination activities were continuing as of the end date of this inspection and will be tracked as Inspector Followup Item (IFI) 50-251/88-25-02.
(Opened)
IFI 50-251/88-25-02, Review licensee decontamination program results in cleanup of spill of August 15-16, 1988.
No violations or deviations were identified.
Summary of Event Circumstances and Immediate Cause '(93702)
The immediate cause of -the spi 1-1 was an open vent valve (84-915A)
on centrifugal pump (4A) in the Unit 4 spent fuel pool heat exchanger (cooling) circulation loop.
The pump was located in the Unit 4 SFP heat exchanger room.
The purpose of. the vent valve was to vent air from the pump body prior to starting the pump; air in the pump body could result in cavitation or binding.of the pump if not relieved.
Contractor construction workers were working in the immediate vicinity of'he pump as late as 10:00 p.m.,
on the night of August 15, 1988.
Upon exiting the heat exchanger room, the door was locked at 10: 10 p.m.,
by the HP technicians accompanying the construction workers.
At that time (10:10 p.m.),
no water was observed coming from the valve, there was no water on the floor, and no contamination of any of the construction workers or of the HP technicians was detected at the RCA exit control point.
At 12:03 a.m.,
on August 16, 1988, about two hours after the last known occupants of the heat exchanger room left the room and locked the door; a
Unit 4 SFP water level alarm (set at-56'0") was received at the Control Room panel.
Shortly after 12:03 a.m., unidentified water was reported on the Auxiliary Building floor, coming from backed-up floor drains.
At.
12: 10 a.m.,
the HP Supervisor relayed a report to the Control Room of water coming from the heat exchanger room door and an operator was dispatched to investigate.
The operators entered the heat exchanger room and observed water flowing from valve 4-915A discharge.
The operator attempted to close the valve but was unable to. fully close the valve.
The operator then left the room to obtain a valve wrench, returned, and closed the suction valve to the 4A SFP pump, stopping the lea i
No violations or deviations were identified.
Contributing Factors (93702)
The radioactivity level of 2.3 E-02 uCi/ml 'in the SFP water was higher than typical values of 1.0 E-04 uCi/ml reported by several other PWRs.
Although this was not a root cause of the event, the event would have been of lesser significance had the SFP water activity level been lower.
A review of weekly SFP water sample analyses for the period February 1-June 30, 1988, indicated that when the SFP filter and demineralizer were used in series with the heat exchanger in the cooling water loop, the Co-60 activity was maintained in the 5.0 E-04 uCi/ml range.
However, when the filter and demineralizer were switched over to process the Refueling Water Storage Tank water, as was the licensee's practice, the Co-60 level in the SFP increased over a period'of six to eight weeks to the 1.0 E-02 to 2.0 E-02 uCi/ml range - the approximate level of Co-60 concentration in the spill of August 15-16, 1988.
From discussions between the inspector and licensee personnel, it appeared that management had not been made aware of the cyclic nature of the concentrations of Co-60 activity in the SFP.
Cobalt-60 is a
neutron activation product resulting from the in-core irradiation of particulate (insoluble)
or soluble Co-59 assumed to be present in the primary coolant stream of a reactor as a corrosion product resulting from either chemical corrosion or mechanical wear, galling, or abrasion of stainless steel reactor components or special materials such as stellite valve seat faces.
The almost total absence of,Co-58 in laboratory analyses of samples taken during the event appeared to indicate that the source of the material had been out of a neutron flux for over a year.
Fuel stored in the Unit 4 SFP had been out of the reactor for about two years, which was consistent with the absence of Co-58 in water analyses.
While Co-60 does not originate in irradiated fuel, it is known that it is found as
"crud" on reactor fuel surfaces and on many other surfaces of primary coolant system components.
For example, deposits of Co-60 in steam generator tubes have been responsible for. much of the radiation dose received in steam generator maintenance during refueling shutdowns at PWRs.
Recent experience at Turkey Po'int has demonstirated that operation of the SFP demineralizer was capable of maintaining the Co-60 concentration in the SFP in the 1.0 E-04 uCi/ml range.
However, the SFP filter-demin-eralizer 'was also intended, by design, to serve the Refueling Water Storage tank (RWST).
Recent filter-demineralizer practice at Turkey Point was to use the filter demineralizer loop to service the RWST 80 to 90 percent of the available time and the SFP 10 to 20 percent of the tim Based on a review of weekly SFP water sample analyses for the period of February 4, 1988, through June 30, 1988, Co-60 activity levels appeared to have reached values in the 1.0 E-02 uCi/ml to 2.0 E-02 uCi/ml range twice.
In each case, a one-week operation of the filter-demineralizer train was sufficient to reduce concentrations to 4.0 E-04 to 7.0 E-04 uCi/ml; on a
third occasion, there was apparently no reduction in Co-60 activity.
Based on
. analysis history and extrapolation from June 30, 1988 to August 18, 1988, it appeared that the filter-demineralizer system had. not been used to service the SFP for approximately 13 weeks at the time of the spill, that the activity, level was at its highest point in over six months, but had not reached a maximum equilibrium value.
The cause or source of the continuously appearing Co-60 was not clear and had not been firmly established as of the end date of the inspection.
The licensee had, however, initiated a review of the operation of the SFP filter-demineralizer system and of the criteria for initiating operation of the system.
IFI 50-251/88-25-03 was opened to track licensee action on
.
this matter.
A factor which contributed to the extent of the spill was the inability of the heat exchanger room floor drain and Auxiliary Building Floor Drain System (ABFDS) to accommodate 'the flow of water coming from the open vent valve '(Valve 4-915A, see also Paragraph 4).
The design basis for'he ABFDS was
GPM of standing water.
The maximum flow rate of water from the open vent valve was calculated by the licensee to be approximately
GPM.
While the ABFDS was also designed for a maximum flow of 60 GPM, it should be recognized that the system design.
flow was established, on the basis of many pipe runs converging on a
common header and that a single long, essentially horizontal run of drain pipe would present a restriction such that gravity flow from the point of origin at a single floor drain to the header could not be expected, to reach
GPM.
Another factor which may have contributed to the inability of the heat exchanger room floor drain to accommodate more flow than it did was the presence of two one-inch diameter plastic tubes which had been inserted in the floor drain opening and which limited drainage flow to an undetermined extent.
Such tubes were in common use at the licensee facilities to channel water leak-offs directly to the dr ain instead of dripping on the floor and possibly leading to extensive area contamination.
The fact that the ABFDS "backed-up" at not less than four points in the Auxiliary Building was indicative that a problem of more general nature existed in the ABFDS.
The back-ups showed that downstream piping was restricted such that it could not carry the limited flow which entered the system at the SFP heat exchanger room.
The condition had existed previously, as illustrated by such comments as
"The floor drain always backs up when it rains".
As of the end date of the inspection, the licensee had expanded a pre-existing work request for clean-out of clogged floor drains'and was "roto-rooting" all floor drain lines to eliminate blockages; sediments or other restrictions.
The results of that program were-to be reviewed during a subsequent inspection.
IFI 50-251/88-25-04 was opened to track licensee action on this matte (Opened)
IFI 50-251/88-25-03:
Review licensee action concerning operation of the spent fuel pool cleanup filter-demineraliizer to limit radioactivity concentrations in pool water.
(Opened)
IFI 50-251/88-25-04:
Review licensee action concerning cleanout of Auxiliary Building floor drain lines and determine system flowrate capacity.
No violations or deviations were identified.
9.
Exit Interview The inspection scope and results were summarized on August 19, 1988, with those persons indicated in Paragraph 1.
The inspector described the areas inspected and discussed in detai 1 the inspection results listed below.
Proprietary information is not contained in this report.
Dissenting comments were not received from the licensee.
The inspector estimated not more than 100 gallons-of water from the SFP escaped directly into the plant storm drain system as.
a result of the spill which occurred on the night of August 15-16, 1988.
The root cause of the spill had not been firmly established as of the end of the report period but was related to the failure of SFP Pump 4A.
The cause of failure of SFP Pump 4A was an improper installation of an oiler which resulted in. insufficient lubrication of shaft bearings.
On August 30, 1988, the licensee was notified that the inadequate procedures in the assembly and installation of the pump subsequent to prior failures (Paragraph 5) would be a violation.
VIO 50-251/88-25-01, Inadequate Procedure for Installation of the 4A SFP Cooling Pump.
Three inspector followup items were identified:
a.
IFI 50-251/88-25-01, Review Licensee Decontamination Program Results in Cleanup of August 15-16, 1988, Spill.
b.
C.
IFI 50-251/88-25-03, Review Licensee Action Concerning Operation of the Spent Fuel Pool Cleanup Filter - Demi neralizer.
IFI 50-251/88-25-04, Review Licensee Action Conceirning Cleanout of the Auxiliary Building Floor Drain Lines and Determine System Flow Rate Capacit ll 10.
Acronyms and Initialisms ABFDS Auxiliary Building Floor Drain System ERT Event Response Team GPM Gallons Per Minute HP
'ealth Physics IMA Independent Management Appraisal NO Nuclear Operator RCA, Radiation Control Area RWST Refueling Water Storage Tank SFP Spent Fuel Pool
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