IR 05000302/1992030
| ML20034F206 | |
| Person / Time | |
|---|---|
| Site: | Crystal River  |
| Issue date: | 02/10/1993 |
| From: | Freudenberger, Holmesray P, Landis K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML20034F203 | List: |
| References | |
| 50-302-92-30, NUDOCS 9303020397 | |
| Download: ML20034F206 (9) | |
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UNITED STATES
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NUCLEAR REGULATORY COMMISslON
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Report No.:
50-302/92-30 Licensee: Florida Power Corporation 3201 34th Street, South St. Petersburg, FL 33733 Docket No.:
50-302 License No.: DRP-72 Facility Name: Crystal River 3 Inspection Conducted: December 20, 1992 - January 16, 1993 Z!/c!8 Inspector:
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31 P. Holites-R'ay, Senior Rbsident Inspector Date Signed Inspector: b d h.uud 0 eac r 2//ck3 R. Freudenb ger, Res'ident Inspector Da'te Signed Approved by:
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K. Landis, Section Chief Date Signed Division of Reactor Projects
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Accompanying Personnel:
A. Long, Project Engineer, RII SUMMARY Scope:
This routine inspection was conducted by two resident inspectors in the areas of plant operations, security, radiological controls, Licensee Event Reports, facility modifications, and licensee action on previous inspection items.
Numerous facility tours were conducted and facility operations observed.
Backshift inspections were conducted on December 29 and 31, and on January 12, 13, 14 and 18.
Results:
In the area of plant operations, the following were identified:
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On December 29, the unit tripped from full power, as the result of high reactor coolant system pressure due to a loss of main feedwater to the
"B" Steam Generator. Operator response to the transient was appropriate.. (paragraph 3.e.)
A Spent Fuel System valve misposition was considered an example of the
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need for improvement in. attention to detail by operations personnel.
(paragraph 3.b.)
9303020397 930211 PDR ADOCK 05000302 W
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In the area of. maintenance / surveillance, A temporarily installed rigging support during inspection of the "A"
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spent fuel heat exchanger was anchored to a safety related support without an engineering evaluation. This item is identified as NC5 50-
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302/92-30-01, Temporary rigging anchored to safety related hanger.
(paragraph 4.a.)
In the area of engineering / technical support, Actions which provided for the identification of the true root cause of
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the plant trip on December 29, prior to restart of the unit were considered a strength.
(paragraph 3.a.)
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An Unresolved Item ** was identified concerning the adequacy of the engineering evaluation of degraded studs (URI 50-302/92-30-02, paragraph 4.b.)
Two LERs were closed.
(paragraph 5)
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LER 92-22:
Inadequate Lube Oil Collection Tank Reserve Capacity Due to Personnel Error Results in Operation Outside Appendix R Design Basis.
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LER 92-26:
Replacement of Failed Reactor Coolant System Flow Transmitter Causes Voluntary Entry into TS 3.0.3.
- Unresolved Items are matters about which more information is required to determine whether they are acceptable or may involve violations or deviation.
REPORT DETAILS 1.
Persons Contacted Licensee Employees
- G. Boldt, Vice President Nuclear Production
- R. Davis, Manager, Nuclear Plant Maintenance E. Froats, Manager, Nuclear Compliance
- H. Gelston, Supervisor, Site Nuclear Engineering Services
- B. Hickle, Director, Nuclear Plant Operations
- S. Johnson, Nuclear Chemistry and Radiation Protection Superintendent
- G. Longhouser, Nuclear Security Superintendent
- W. Marshall, Nuclear Operations Superintendent P. McKee, Director, Quality Programs
- B. Moore, Manager, Nuclear Integrated Scheduling
- S. Robinson, Manager, Nuclear Quality Assessments
- W. Rossfeld, Manager, Site Nuclear Services
- L. Santilli, Supervisor, Nuclear Calibration Material Quality Control
- J. Terry, Supervisor, Site Nuclear Engineering Services R. Widell, Director, Nuclear Operations Site Support K. Wilson, Manager, Nuclear Licensing Other licensee employees contacted included office, operations, engineering, maintenance, chemistry / radiation, and corporate personnel.
NRC Resident Inspectors
- P. Holmes-Ray, Senior Resident Inspector
- R. Freudenberger, Resident Inspector
- Attended exit interview Acronyms and initialisms used throughout this report are listed in the last paragraph.
2.
Plant Status and Activities The plant was operating at full power at the beginning of the report period. The plant tripped from full power on December 29, and returned to power operation on December 31.
Power operation continued for the remainder of the inspection.
On December 22, 1992, the Deputy Director, Division of Reactor Projects, Region II, was on site for a management visit.
During the week of January 4,1993, specialist inspections were conducted by Region II personnel in the areas of Radiation Protection and MOVs. The results of these inspections are documented in NRC Inspection Reports 50-302/93-01 and 50-302/93-02.
During the week of January 11, 1993, a specialist inspection of Radwaste was conducted. The results of this inspection are documented in NRC Inspection Report 50-302/93-0.
Plant Operations (71707, 93702, & 40500)
Throughout the inspection period, facility tours were conducted to observe operations and maintenance activities in progress. The tours included entries into the protected areas and the radiologically controlled areas of the plant. During these inspections, discussions were held with operators, health physics and instrument and controls technicians, mechanics, security personnel, engineers, supervisors, and plant management.
Some operations and maintenance activity observations were conducted during backshifts.
Licensee meetings were attended by the inspector to observe planning and management activities. The inspections confirmed FPC's compliance with 10 CFR, Technical Specifications, License Conditions, and Administrative Procedures.
a.
Reactor Trip On December 29, 1992, at 4:12 a.m., Crystal River Unit 3 tripped from full power. The reactor tripped on high reactor coolant system pressure as the result of a loss of main feedwater to the "B" 0TSG. The initial Event Notification (EN 24804) of the reactor trip indicated that
" Operators tripped MFW manually to bring about an emergency feedwater-system actuation." However, based on post trip data review and operator interviews, it was subsequently determined that emergency feedwater automatically initiated on low OTSG 1evel approximately one minute after the trip. Main feedwater pumps were tripped by the operators within the following minute to provide improved control of feedwater flow to the OTSGs.
Operator response to the transient was appropriate.
Licensee and inspector review of post trip data identified no safety system failures.
The initial evaluation of the cause of the trip was based on main control board indications. The "B" loop main feedwater flow instrument in service (SP-88-FTI) failed high during the transient, and was initially assumed to be the cause of the transient. The expected Integrated Control System response to this failure would have been the reduction of the speed and therefore flow from the "B" main feedwater pump which supplies the "B" OTSG when the plant is operating at full power.
The fact that these conditions occurred, supported the failure of the main feedwater flow instrument as the cause of the plant trip.
Subsequent investigation determined that the failed flow instrument was not the cause of the transient. As the result of minor feedwater system oscillations observed early in the inspection period, the licensee had installed a computer based data acquisition and analysis system which monitored several of the control parameters associated with "B" main feedwater flow.
Post trip analysis of this and plant data supplied from the Recall system indicated that the
"B" main feedwater pump speed and feedwater flow began to decrease with an increasing demand signal from ICS prior to, but within seconds of the failure of the main feedwater flow instrument.
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Troubleshooting of the "B" main feedwater pump controls identified dirt buildup in the hydraulic governor. The loss of main feedwater to the
"B" OTSG was caused by the resultant erratic operation of the governor.
The "B" main feedwater pump governor and the feedwater flow transmitter associated with instrument SP-88-FT1 were replaced prior to restart of the unit.
A failure analysis of the failed differential pressure transmitter was planned.
The inspector considered the licensee's actions to identify the true root cause of the trip prior to restart of the unit to be commendable.
- Without a detailed evaluation of the information available, the cause of the trip may have been assigned to the failed main feedwater flow instrument.
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b.
Valve Misposition On January 12, while initiating recirculation of the BWST for the performance of SP-320, " Operability of Boron Injection Sources and Pumps," approximately 2000 gallons of borated water was inadvertently transferred from the BWST to the spent fuel pools. This resulted in a slight increase level in the spent fuel pools but no overflow. Valve SFV-54 was found to be mispositioned, in the open position. The valve is located in the overhead of the auxiliary building and is equipped with a chain operator. The valve was hard on its backseat, and the
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operator thought it was closed when he was unable to move it in the close direction.
The licensee initiated a Problem Report to address the j
misposition of the valve. A human performance evaluation of the valve
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misposition was underway at the end of the report period. The licensee plans to modify the valve to provide clear indication of its position.
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This event was noteworthy as an example of a need for improvement in attention to detail by operations personnel.
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Radiological Protection Program i
Radiation protection control activities were observed to verify that these activities were in conformance with the facility policies and
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procedures, and in compliance with regulatory requirements. These observations included:
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Entry to and exit from contaminated areas, including step-off pad conditions and disposal of contaminated clothing;
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Area postings and controls;
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Work activity within radiation, high radiation, and contaminated areas;
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RCA exiting practices; and
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Proper wearing of personnel monitoring equipment, protective clothing, and respiratory equipment.
The implementation of radiological controls associated with the Spent Fuel Heat Exchanger Inspection, Spent Fuel Valve SFV-25 rebuild, and
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Reactor Building entries observed during this inspection period were proper and conservative.
d.
Security Control In the course of the monthly activities, the inspector included a review of the licensee's physical security program. The performance of various shifts of the security force was observed in the conduct of daily activities to include:
protected and vital areas access controls; searching of personnel, packages, and vehicles; badge issuance and retrieval; escorting of visitors; patrols; and compensatory posts.
In addition, the inspector observed the operational status of protected area lighting, protected and vital areas barrier integrity, and the security organization interface with operations and maintenance. No performance discrepancies were identified by the inspectors.
Violations or deviations were not identified.
4.
Maintenance and Surveillance Activities (62703 & 61726)
Surveillance tests were observed to verify that approved procedures were being used; qualified personnel were conducting the tests; tests were adequate to verify equipment operability; calibrated equipment was utilized; and TS requirements appropriately implemented.
The following tests were observed and/or data reviewed:
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SP-113, Power Range Nuclear Instrumentation Calibration;
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SP-150, Operability and Functional Check of the Loose Parts Monitoring Subsystem;
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SP-421, Reactivity Balance Calculations; and
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SP-433, Incore Backup Recorder Calibration.
In addition, the inspector observed maintenance activities to verify
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that correct equipment clearances were in effect; work requests and fire prevention work permits, as required, were issued and being followed; quality control personnel performed inspection activities as required; and TS requirements were being followed.
Maintenance was observed and/or work packages were reviewed for the following maintenance activities:
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WR 306524, Cleaning and Leak Repair of Secondary Services Heat Exchanger;
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WR 306440, Troubleshooting of ICS due to minor Feedwater Control Transient-
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WR 306416, Replacement of ICS Module IC-5-7-14FW Feedwater Delta-P l
Mode for "A" Feedwater Loop;
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WR 306573, Troubleshooting of "E" Inverter using PM-130A due to major oscillations;
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WR 288532, Shaft Seal Leak Repair of Building Spray Na0H Recirculation Pump (BSP-3);
WR 303701, Replacement of Bubbler Glass on Nuclear Services Closed
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Cycle Cooling; WR 306662, Replacement of the "A" Emergency Diesel Generator Speed
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Setter Motor;
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WR 297343, Spent Fuel Heat Exchanger Head Removal for Inspection; and WR 264881, Spent Fuel System Valve, SFV-25 Rebuild.
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The following items were considered noteworthy:
a.
Spent Fuel Heat Exchanger Rigging During the removal of the "A" Spent Fuel Heat Exchanger Head for inspection of the tubes, spent-fuel cooling system inlet and outlet piping was temporarily supported with rigging to steady the piping. The inspector observed that one of the temporary installations was anchored to a support associated with a portion of the spent fuel system that was still in service. Past practice observed by the inspector was to perform an engineering evaluation of temporary installations of this nature prior to installation.
In this case, an engineering evaluation had not been performed. The inspector identified the omission to the system engineer involved with the heat exchanger inspection. The rigging configuration was promptly changed to utilize an acceptable anchor.
Since the rigging was only intended to steady the piping, there was not a significant load on the hanger and the safety significance of this issue was minimal. This NRC identified violation is not being cited because the criteria specified in section VII.B of the NRC j
Enforcement Policy were satisfied. This item is identified as NC5 50-
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302/92-30-01, Temporary rigging anchored to safety related hanger.
The inspectors plan to monitor the appropriate use of rigging equipment in future inspections.
b.
Spent Fuel System Valve Rebuild Spent Fuel System Valve, SFV-25, was rebuilt as the result of a seat leak in the valve.
Procedure MP-118, Valve Maintenance for Bolted and Screwed Type Bonnets, included an inspection of the bonnet studs prior to reinsta11ation. The inspection required, in part, that the threads
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of the studs be chased with the nuts the full length of the stud. When this portion of the inspection failed, and no replacement studs were available, system engineering was contacted for assistance. An REA, number 930039, was processed to disposition the use of the studs.
In the description of the request, the REA stated that the body to bonnet
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studs had minor deformation (necking down) between the portions of_the stud that engaged the nuts. Necking down would indicate that the stud material had been stressed beyond yield point at some time.
Behavior of the material under load would then be unpredictable. The response to the REA stated that the portion of the studs that engage the nuts was unaffected and no signs of cracking was present in any of the studs, therefore they were acceptable for use as is. No detailed visual or non-destructive testing of the studs was performed.
Following reassembly, the body to bonnet joint leaked, apparently due to difficulties with the gasket.
Replacement studs of the proper material were available to replace the damaged studs during the rework of the valve. This issue is unresolved pending disposition as to the adequacy of the engineering evaluation. This issue is identified as URI 50-302/92-30-02, Adequacy of engineering evaluation of degraded studs.
Violations or deviations were not identified.
5.
Review of Licensee Event Reports (92700)
LERs were reviewed for potential generic impact, to detect trends, and to determine whether corrective actions appeared appropriate.
Events that were reported immediately were reviewed as they occurred to determine if the TS were satisfied.
LERs were also reviewed in accordance with the current NRC Enforcement Policy.
a.
(Closed) LER 92-22:
Inadequate Lube Oil Co11cetion Tank Reserve Capacity Due to Personnel Error Results in Operation Outside Appendix R Design Basis On October 15, 1992, CR-3 was operating in Mode 1 (power operation) at 92% of rated thermal power. At 12:40 p.m., it was discovered that the reactor coolant pump LOTS exhibited a fluid level of 19%. This level was in excess of the plant's administrative limit for the tanks.
Further analyses revealed that insufficient reserve volume existed in the LOTS to meet the design requirements of 10 CFR 50, Appendix R.
The discovery of excessive inventory in the LOTS was made during an investigation necessitated by an inadvertent spraying of the RB atmosphere. The RB spray flow was initiated earlier that day due to personnel error during the performance of a routine plant surveillance procedure. The LOTS were pumped down to acceptable levels in a timely manner.
Resolution of corrective actions associated with the cause of the RB spray will be tracked by NRC Violation 50-302/92-27-01. This LER'
is closed.
b.
(Closed) LER 92-26:
Replacement of Failed Reactor Coolant System Flow Transmitter Causes Voluntary Entry into TS 3.0.3
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On December 8,1992, at 9:05 p.m. and 11:10 p.m., CR-3 voluntarily entered TS LCO 3.0.3 while replacing a RCS flow transmitter in the "B" channel of the RPS. TS 3.0.3 was entered during isolation and restoration of the "B" channel transmitter by placing the "C" RPS
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I chancel in bypass. The RPS TS 3.3.1.1 does not allow bypassing a l
channel for maintenance purposes while another channel is inoperable and tripped.
Entry into TS 3.0.3 is considered a condition prohibited by TS and is reportable in accordance with 10 CFR 50.73.
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Early on December 8,1992, the RCS flow transmitter in the "B" RPS channel failed.
In accordance with TS 3.3.1.1, the channel "B" RPS channel was placed in a tripped condition.
During the transmitter replacement, there was a high probability that a pressure variation would occur in the instrument sensing lines during transmitter isolation and restoration. This type of localized pressure variation could cause a trip of the "C" channel on flux / delta flux / flow. With the "B" channel tripped, a trip of the "C" channel would cause a reactor trip.
Previous operating experience at a similar plant indicated pressure variations were likely while valving in and out of the flow transmitters. A teleconference was initiated by the licensee on December 8, prior to placing the "C" channel in bypass.
The purpose of the teleconference was to discuss placing the "C" channel in bypass while the "B" channel was in the tripped condition and considered inoperable.
Representatives of the licensee, NRC Region II, NRR, and the resident inspectors were involved in the teleconference. Reactor power was held at approximately 90% and the "C" RPS channel was placed in bypass while isolating the failed transmitter. When the replacement transmitter was installed, the
"C" channel was again bypassed for several minutes while the isolation valves were reopened.
By 1:00 a.m. on December 9, 1992, the post maintenance test of the replacement flow transn..1er was completed satisfactorily and the "B" RPS channel was returned to an active state.
This LER is closed.
Violations or deviations were not identified.
6.
Exit Interview The inspection scope and findings were summarized on January 21, 1993, with those persons indicated in paragraph 1.
Proprietary information is not contained in this report. Dissenting comments were not received from the licensee.
Item Number Status DescriDtion and Reference NC5 50-302/92-30-01 CLOSED Temporary rigging anchored to safety related hanger URI 50-302/92-30-02 OPEN Adequacy of engineering evaluation of degraded studs LER 92-22 CLOSED Inadequate Lube Oil Collection Tank Reserve Capacity Due to Personnel Error Results in Operation Outside Appendix R Design Basis
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LER 92-26 CLOSED Replacement of Failed Reactor Coolant System Flow Transmitter Causes Voluntary Entry into TS 3.0.3 7.
Acronyms and Abbreviations a.m.
- ante meridiem BWST - Borated Water Storage Tank CFR
- Code of Federal Regulations EN
- Event Notification FPC
- Florida Power Corporation ICS
- Integrated Control System LCO
- Limiting Condition for Operation LER
- Licensee Event Report LOT
- Motor Operated Valve MP
- Maintenance Procedure NRC
- Nuclear Regulatory Commission NRR
- NRC Office of Nuclear Reactor Regulation OTSG - Once Through Steam Generator p.m.
- post meridiem PM
- Preventive Maintenance RB
- Reactor Building RCA
- Radiation Control Area RCS
- Reactor Coolant System REA
- Request for Engineering Assistance RPS
- Reactor Protection System SP
- Surveillance Procedure TS
- Technical Specification WR
- Work Request
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