IR 05000269/1989011
| ML15224A534 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 04/20/1989 |
| From: | Skinner P NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML15224A533 | List: |
| References | |
| 50-269-89-11, 50-270-89-11, 50-287-89-11, NUDOCS 8905030325 | |
| Download: ML15224A534 (10) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION
REGION II
101 MARIETTA STREET, ATLANTA, GEORGIA 30323 Report Nos:
50-269/89-11, 50-270/89-11, 50-287/89-11 Licensee:
Duke Power Company 422 South Church Street Charlotte, Docket Nos.:
50-269, 50-270, 50-287 License No DPR-38, DPR-47, DPR-55 Facility Name:
Oconee Nuclear Station Inspection Conducted:
Mach 18 - April 14, 1989 Inspectors: Ine, Senior sident Inspector M6te igned t
Resident nspector at Signed Approved b (___&_
___
Mh. B. Shymlock, Section Chief Date igned Division of Reactor Projects SUMMARY Scope:
This routine, announced inspection involved resident inspection on-site in the areas of operations, surveillance testing, maintenance activities, safeguards and radiation protection, and inspection of open item Results:
During this period the inspectors noted a significant increase in the level of overall cleanliness throughout the plant. Housekeeping efforts appeared particularly vigorous and improved cleanliness conditions in many locations noted previously as needing more attentio Several minor weaknesses were noted during observation of functional testing of the Safe Shutdown Facility Diesel Generator, para graph A Licensee Identified Violation concerning inoperability of the Emergency Condenser Circulating Water system due to a mispositioned valve is documented in paragraph (III)
REPORT DETAILS 1. Persons Contacted Licensee Employees M. Tuckman, Station Manager C. Boyd, Site Design Engineer Representative Brackett, Senior QA Manager
- J. Davis, Technical Services Superintendent
- D. Detheraae, Operations Support Manager
- W. Foster, Maintenance Superintendent T. Glenn, Instrument and Electrical Support Engineer
- D. Havice, Instrument & Electrical Engineer C. Harlin, Compliance Engineer D. Hubbard, Performance Engineer
- E. Legette, Assistant Engineer Compliance H. Lowery, Chairman, Oconee Safety Review Group JI. McIntosh, Administrative Services Superintendent G. Rothenberger, Integrated Scheduling Superintendent
. Sweigart, Operations Superintendent Other licensee employees contacted included technicians, operators, mechanics, security force members, and staff engineer NRC Resident Inspectors:
- PHr Skinner
- L.D. Wert
- Attended exit intervie. Plant Operations (71707)
a. The inspectors reviewed plant operations throughout the reporting period to verify conformance with regulatory requirements, technical specifications (TS), and administrative control Control room logs, shift turnover records, and equipment removal and restoration records were reviewed routinel Discussions were conducted with plant operations, maintenance, chemistry, health physics, instrument
& electrical (I&E), and performance personne Activities within the control rooms were monitored on an almost daily basi Inspections were conducted on day and on night shifts, during weekdays and on weekend During one such backshift inspection an approach to criticality was observe Some
inspections were made during shift change in order to evaluate shift turnover performanc Actions observed were conducted as required by the Licensees Administrative Procedure The complement of licensed personnel on each shift inspected met or exceeded the requirements of T Operators were responsive to plant annunciator alarms and were cognizant of plant condition Plant tours were taken throughout the reporting period on a routine basis. The areas toured included the following:
Turbine Building Auxiliary Building Units 1, 2 and 3 Electrical Equipment Rooms Units 1, 2 and 3 Cable Spreading Rooms Units 1, 2 and 3 Penetration Rooms Station Yard Zone within the Protected Area Standby Shutdown Facility Units 1/2 Spent Fuel Pool Room Keowee Hydro Station During the plant tours, ongoing activities, housekeeping, security, equipment status, and radiation control practices were observe Unit 1 -
Operated at 100 percent power for this entire reporting perio Unit 2 -
Began this report period at 100 percent power and remained at that power level until April 3, 1989 when a reactor trip occurre The trip was caused by a loss of main feedwater pumps due to a loss of condensate booster pumps (paragraph 2.b.).
The unit was returned to full power operation on April 4. Unit 2 was taken off line on April 6 to repair a ground in the generator exciter fiel After repairs were completed the unit was returned to 100 percent full power on April 9 and operated at that level for the remainder of the reporting perio Unit 3 -
Operated at 100 percent power for this entire reporting perio b. Unit 2 Reactor Trip At approximately 10:05 a.m. on April 3, 1989, Oconee Unit 2 tripped from 100% powe The trip was caused by the loss of both main feedwater pumps which had resulted from a loss of the condensate booster pump The condensate booster pumps had tripped due to an erroneous low suction pressure signa This signal was caused by a piece of threaded rod (2 inch diameter and about 3 inches long)
falling about twenty feet (through a hole in the floor above) and striking the condensate booster pump suction pressure transmitte Markings on the transmitter and the nearby concrete floor fully support this explanatio The licensee's investigation into what caused the piece to fall through the hole has not disclosed any additional detail At the time the trip occurred, the licensee was conducting an emergency drill which simulated a casualty on Unit 1. The drill was immediately secure The unit was quickly stabilized on emergency feedwater (EFW)
and all major systems performed as expecte The main steam relief valves all fully reseated without operator actio In initial reports it was speculated that a noise which had been heard in the control room after the trip had been caused by water hammer in a secondary syste The licensee has walked down all concerned piping and found no indications that a water hammer occurre It is believed that the noise (rumble) was caused by relatively cold (150-16,0 degrees F) EFW flowing into the Main Feedwater line The licensee is also investigating why several small electric loads apparently were slow to shift power or momentarily lost power during the shift to the auxiliary power sourc These loads did not effect the recovery and further analysis may require refueling outage condition The inspector was in the control room during the trip and observed the recovery action The condensate booster pump pressure transmitter was recalibrated and the unit was returned to power operation on the evening of April The inspectors will continue to follow the licensees actions regarding prevention of future occurrence Consideration is being given to construction of shielding around such potential reactor trip hazards and providing labels which identify such hazard C. Safe Shutdown Facility (SSF) Diesel Generator Testing The inspector observed a post maintenance functional test of the SSF diesel generato Just prior to witnessing the test, the inspector walked down the diesel fuel oil system to obtain information for TI 2515/100:
Emergency Diesel Generator Fuel Oil Issue The inspector questioned the operators preparing to run the diesel generator about the alignment of the valves controlling fuel oil flow to the duplex fuel strainers. On both diesel engines, the fuel oil strainer inlet/outlet combination valve was in the middle position (labeled as 'off') rather than positioned to admit flow to one strainer or the other as required by OP/O/A/1600/03:
SSF Fuel Oil Lineup For Normal Operation. The operators recognized that this alignment was improper and indicated that their understanding was that this position secured fuel oil flow to the diese Subsequent review of drawings of the valve internals and discussions with the
vendor by the licensee indicate that in the mid position flow is admitted to both the strainers simultaneousl The diesel was run unloaded with the valves in the mid positio It is not clear whether this valve is intended to be placed in the mid position for normal diesel operation or simply constructed this way to allow shifting of strainers while the diesel is running. Subsequently the licensee obtained information which indicated that sufficient fuel flow would be available to support full load operation with the valve in the mid positio Several other discrepancies were noted by the inspectors;
-
While the fuel oil strainer valves (SSF-FO-74 and 75)
were labeled for the 'A' diesel engine, the strainer valves on the
'B' engine (SSF-FO-85 and 86) were not labele The inspector found the labels for FO-85 and FO-86 on the engine 'B'
differential pressure instrument root valves for the fuel oil filte OP/O/A/1600/03 (Enclosure 3.1)
had been changed in December 1988 requiring the fuel filter inlet switch to be positioned to
'both' to place both filters in service. On December 16, 1988, the Enc.1 lineup was completed and apparently the above labeling problem and a lack of knowledge regarding fuel oil strainers and fuel oil filters caused the strainer valve to be improperly positione The terms 'filters'
and 'strainers'
apparently are used interchangeably in the procedures and on labels, leading to some confusio The Alarm Response Procedures for the diesel generator annunciator panel state that on a high fuel oil filter differential pressure the operator will shift to the nonoperating fuel oil filte Since both filters are required to be in service, this procedure is no longer vali The actions promulgated in the Alarm Response Procedures are critical to sustaining diesel generator operation if abnormalities occu The licensee took prompt action to correct the labeling discrepancies and is also reviewing the alarm response procedures to ensure they are current and correct. The inspectors questioned the decision to run the diesel with both fuel oil filters simultaneously onlin Although a filter differential pressure indication is available and spare filters are on site, this configuration allows the possibility of both filters becoming blocked and could result in a loss of the diese The licensee is reviewing this decision. All indications are that the diesel was not rendered inoperable by the improper lineup of the strainers. No violation or deviation was
note IFI 269,270,287/89-11-01:
SSF Diesel Generator Fuel Oil System Issues, will be utilized to follow the licensees action d. Emergency Condenser Cooling Water (ECCW) Steam Air Ejector Inoperability The Condenser Circulating Water (CCW)
System for the three Oconee units is supplied water from Lake Keowee through an intake structure with 12 CCW pumps whose suctions extend below the maximum draindown level of the lak The CCW system also supplies water to the Low Pressure Service Water (LPSW)
system which provides various safety related cooling function The CCW system discharge is normally returned to Lake Keowe The CCW system is designed such that on a loss of power situation (loss of CCW pumps),
gravity flow and a siphon effect will cause continued flow through the pipin A siphon is initiated at system startup by vacuum pumps and maintained by continuous vacuum priming pumps during operatio In the event of a loss of all power, an emergency discharge path (a 48 inch discharge line to the Keowee Dam tailrace) will automatically open and flow will continue through the CCW system, providing condenser flow for decay heat removal and LPSW supply for cooling requirement During such operation the vacuum to sustain siphon flow from the intake structure is maintained by steam air ejector On February 22, 1989, during a periodic test the licensee discovered that IMS-45, the main steam supply valve to the emergency steam air ejector was close Technical Specification 3.4.5a requires that whenever the reactor is above 250 degrees F, the ECCW system shall be operabl LER 269/89-05 states that the steam supplied air ejector must function to remove noncondensible gases to ensure the siphon will functio The primary reason that the valve was incorrectly shut was that the Unit 1 CCW system valve checklist did not include this valv Consequently, during CCW system startup after an outage in which valve 1MS-45 was replaced, the valve was not opene During unit startup the control room operators were required only to verify that the valve checklist had been completed and that the main steam system was in servic Immediately upon being discovered shut, 1MS-45 was opene The valve has subsequently been added to OP/1/A/1104/12 (Enclosure 4.19):
Valve Checklist for CCW System. Additionally the CCW system startup procedures; OP/1,2,3/A/1104/12 (Enc.1) were revised to provide clear directions on verification of steam to the emergency air ejector Statements in the FSAR and LER 269/89-05 indicate that the continuous vacuum priming system or its backup, the steam emergency air ejector must function correctly to maintain siphon and gravity flow of CCW through the condenser Each refueling outage the ECCW system flow is tested for 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, during which neither the continuous vacuum primary system nor the air ejector is
utilized. During these tests, the siphon flow from the intake to the LPSW supply has been maintained successfull In addition to steam relief through the turbine bypass valves to the condenser there are other ways to remove decay heat from the steam generators after a loss of powe Steam relief via the Main Steam Relief Valves or the atmospheric dump valves could provide decay heat removal following a station blackout without the use of the ECCW syste Additionally, during a station blackout situation the Safe Shutdown Facility could be use The licensees Design Engineering group is analyzing this situation in order to resolve if steam air ejector operation is required to ensure ECCW operability. A factor that must be considered is that although the periodic test verifies ECCW flow for 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> without the ejector, the test is done under cold plant conditions. If the ECCW system was removing decay heat by condensing steam it would be heated up possibly releasing entrained gases and affecting siphon flo Since available information indicates the air ejector is required for ECCW operability, 1MS-45 being shut violated TS 3.4.5 This violation meets the criteria specified in Section V of the NRC Enforcement Policy for not issuing a Notice of Violation and is not cite This is documented as Licensee Identified Violation 50-269/89-11-02:
ECCW Steam Air Ejector Inoperabilit Based on the actions completed by the licensee, this item is close One Licensee Identified Violation was identifie. Surveillance Testing (61726)
Surveillance tests were reviewed by the inspectors to verify procedural and performance adequac The completed tests reviewed were examined for necessary test prerequisites, instructions, acceptance criteria, technical content, authorization to begin work, data collection, independent verification where required, handling of deficiencies noted, and review of completed wor The tests witnessed, in whole or in part, were inspected to determine that approved procedures were available, test equipment was calibrated, prerequisites were met, tests were conducted according to procedure, test results were acceptable and systems restoration was complete Surveillances reviewed and witnessed in whole or in part:
PT/1/A/600/13 Motor Driven Emergency Feedwater Pump Performance Test PT/O/A/0250/25 Annual Fire Protection Performance Test PT/O/A/0150/22K Emergency Condenser Circulating Water Valves Quarterly Function Test OPO/A/1600/10 Operation Of The Safe Shutdown Facility (SSF)
Diesel Generator (Normal Start)
While no deviations or violations were identified, several weaknesses were noted during observation of the SSF diesel generator testing, see paragraph. Maintenance Activities (62703)
Maintenance activities were observed and/or reviewed during the reporting period to verify that work was performed by qualified personnel and that approved procedures in use adequately described work that was not within the skill of the trad Activities, procedures and work requests were examined to verify proper authorization to begin work, provisions for fire, cleanliness, and exposure control, proper return of equipment to service, and that limiting conditions for operation were me Maintenance reviewed and witnessed in whole or in part:
WR 55486 B Perform Electrical PM's on 2LP21 and 2LP5 WR 050610 Repairs to 2A Low Pressure Injection Pump Circuitry No violations or deviations were identified 5. Safeguards and Radiological Controls Activities (71707)
In the course of the monthly activities, the Resident Inspectors included review of portions of the licensee's physical security activitie The performance of various shifts of the security force was observed in the conduct of daily activities which included; protected and vital areas access controls, searching of personnel, packages and vehicles, badge issuance and retrieval, escorting of visitors, patrols and compensatory post The inspectors observed protected area lighting and protected and vital areas barrier integrity, and verified interfaces between the security organization and operations or maintenanc No violations or deviations were identifie.
Inspection of Open Items (92700)
Two of the following open items are being closed based on review of licensee reports, inspection, record review, and discussions with licensee personnel, as appropriate: (Open)
LER 287/88-03: Potential Degraded Performance of Reactor Building Cooling Units (RBCUs) Due to Service Induced Foulin The inspectors continued to follow the licensees ongoing actions to resolve this matte Inspection Report 269,270,287/89-05 discussed the formation of a RBCU task force, the latest testing results and progress made on resolution of this issu On April 7, 1989, the licensee completed testing of the '2A'
and
'2C'
RBCU Results indicated that the coolers had not fouled at all since their January
16, 1989 tes On April 10, 1989, testing was completed on the Unit 3 'A' and 'C' RBCUs which indicated that the coolers had lost only 2% combined capacity due to fouling since their March 22, 1989 tes While the Unit 3 coolers are still fouling and their combined capacity (about 113 percent) is lower than the Unit 1 and Unit 2 coolers (about 140 percent),
it appears that the fouling rate has slowed and the cleaning efforts are achieving capacities which are closer to the other units capacities than prior effort After cleaning in February the test indicated a 133 percent capacity, the highest post cleaning capacity to dat The latest testing trends along with notably lower Unit 3 reactor building temperatures have enabled the licensee to begin formulating an explanation for the Unit 3 RBCU foulin Although the explanation is still not fully conclusive, it appears that a primary system leak in 1985 may have deposited significant amounts of boron throughout the ductwork and cooler surfaces of the RBCU The repeated and improved cleaning efforts are gradually removing the boron deposits from these surfaces, resulting in better thermal performance after each successive cleaning and a reduced fouling rat At this time indications are that air side fouling is the principal contributor to the reduction of cooler performance. The inspectors will continue to follow the licensees actions on this matte b. (Closed) LER 269/88-12:
Incorrect Routing of SSF Incore Thermocouple Cables Due to a Design Deficienc This LER was submitted on a voluntary basis on March 21, 198 The actions described in this report have been reviewed by the inspector and based on this review, this item is close (Closed)
LER 269/87-11, Revision 1:
Cable Room Sprinkler Systems Inoperable Due To Design Deficiency of Pressure And Flow Rate The original LER was initially submitted in correspondence dated January 4, 1988 and was revised by Revision 1 dated April 19, 198 The original LER identified a design deficiency associated with a portion of the fire protection system associated with Unit 3 cable roo The revision identified an additional problem with the inoperability of the Keowee Hydro Station Main Lube Oil Storage Room water spray system. The corrective actions for these problems were reviewed by the inspector Modifications have been completed for both sprinkler system Based on this action, this item is close @
7. Exit Interview (30703)
The inspection scope and findings were summarized on April 14, 1988, with those persons indicated in paragraph 1 abov The following items were discussed in detail:
Item Number Status Description/Reference Paragraph LER 287/88-03 Open Potential Degraded Performance of RBCUs Due to Service Induced Fouling LER 269/88-12 Closed Incorrect Routing of SSF Incore Thermocouple Cables Due to a Design Deficiency LER 269/87-11(Rev.1)
Closed Cable Room Sprinkler Systems Inoperable Due to Design Deficiency of Pressure and Flow Rates IFI 269,270,287/89-11-01 Open SSF Diesel Generator Fuel Oil System Issues LIV 269,270,287/89-11-02 Closed ECCW Steam Air Ejector Inoperability The licensee representatives present offered no dissenting comments, nor did they identify as proprietary any of the information reviewed by the inspectors during the course of their inspectio II