IR 05000269/1992009
| ML16148A645 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 04/23/1992 |
| From: | Binoy Desai, Harmon P, Poertner W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML16148A646 | List: |
| References | |
| 50-269-92-09, 50-269-92-9, 50-270-92-09, 50-270-92-9, 50-287-92-09, 50-287-92-9, NUDOCS 9205120005 | |
| Download: ML16148A645 (11) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION
REGION II
101 MARIETTA STREET, ATLANTA, GEORGIA 30323 C'
Report Nos.:. 50-269/92-09, 50-270/92-09 and 50-287/92-09 Licensee:
Duke Power Company P. 0. Box 1007 Charlotte, NC 28201-1007 Docket Nos.:
50-269, 50-270, 50-287, 72-4 License Nos.:
DPR-38, DPR-47, DPR-55, SNM-2503 Facility Name: Oconee Nuclear Station Inspection Conducted: March 1-28, 1992 Inspectors
P. E. Ha non, Senior Resident Inspector Date Signed
/. B. D i, Resident Inspector Date Signed S_.__
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7, WK. oe tner, Resident Inspector Date Signed A p p r o v e d b y : G. Aoe1g G. A Belsle~~ec~n Chef Date Signed Division of Reactor Projects SUMMARY Scope:
This routine, resident inspection was conducted in the areas of operations, surveillance testing, maintenance activities, and followup of previous inspection finding Results:
Two non-cited violations were identified. Both non-cited violations involved a failure to meet procedural requirements (paragraphs 2.f and 2.h).
The inspectors expressed a concern with management oversight of planned evolutions during the Unit 2 return to power operation after completion of the refueling outage (paragraph 2.e. and 2.f.).
The inspectors identified a followup item related to the volume of water and concentration of boric acid in the concentrated boric acid storage tanks (paragraph 2.d).
9205120005 920424 PDR ADOCK 05000269 Q
REPORT DETAILS 1. Persons Contacted Licensee Employees
- H. Barron, Station Manager S. Benesole, Safety Review
- D. Coyle, Systems Engineering
- J. Davis, Safety Assurance Manager D. Deatherage, Operations Support Manager B. Dolan, Manager, Mechanical/Nuclear Engineering (Design)
W. Foster, Superintendent, Mechanical Maintenance
- J. Hampton, Vice President, Oconee Site 0. Kohler, Regulatory Compliance C. Little, Superintendent, Instrument and Electrical (I&E)
- M. Patrick, Performance Engineer B. Peele, Engineering Manager
- S. Perry, Regulatory Compliance G. Rothenberger, Work Control Superintendent
- R. Sweigart, Operations Superintendent
- R. Todd, Oconee Safety Review Group Other licensee employees contacted included technicians, operators, mechanics, security force members, and staff engineer NRC Resident Inspectors:
- P. Harmon
- W. Poertner
- B. Desai
- Attended exit intervie. Plant Operations (71707)
a. General The inspectors reviewed plant operations throughout the reporting period to verify conformance with regulatory requirements, Technical Specifications (TS), and administrative controls. Control room logs, shift turnover records, temporary modification log and equipment removal and restoration records were reviewed routinely. 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 basis. Inspections were conducted on day and on night shifts, during weekdays and on weekend Some inspections were made during shift change in order to evaluate shift turnover performanc Actions
radiological conditions that are expected to be present during the outag c. Low Pressure Service Water (LPSW) Pump Deadheadin During the previous inspection period, the inspectors became aware that the B LPSW pump shared by Units 1 and 2 had operated for some period of time in a deadheaded or no flow conditio The inspectors became aware of this condition during discussions with plant personnel when trying to determine why the B LPSW pump was being carried on the shift turnover sheets as being out of servic The inspectors determined that on February 9, 1992, the operators in the control room investigated a surging noise above the ceiling of the control room and determined that the noise was coming from the LPSW pipes that supplied various air handling units located above the control roo The operators looked at the LPSW pump discharge pressure and current (amps), and determined that they were cycling. The operators checked the pumps locally and found that the A and B LPSW pumps were running but that the discharge check valve was closed on the B LPSW pum The B LPSW pump was secured and the noise and cycling.stoppe The operators determined that insufficient flow in the system resulted in the pump with the higher discharge pressure keeping the discharge check valve of the other pump shut and resulted in dead heading of the B LPSW pump.,
The inspectors became aware of this event 10 days after it occurre This event was not documented in the operator's logs or on a shift incident report. The inspectors questioned the operations staff on what actions were in progress or were planned to document the event to assure that the pump had not been damage The inspectors were told that the pump would be tested in accordance with ASME Section XI requirement The operations staff also agreed to initiate a shift incident report to document that this event had occurre However, because this problem has occurred previously, a problem identification report (PIR)
also appears to be warranted for this event. The inspectors discussed this item with licensee managemen The inspectors also expressed, concern that testing of a safety-related pump was delayed approximately 3 weeks until the normally scheduled ASME Section XI test was due to be performe Licensee management stated that they did not consider this issue to be significan The corrective action as stated to the inspectors did not appear to be adequat The licensee's corrective action was to perform ASME Section XI testing. This testing is designed to give an indication of long term degradation and will not be indicative of the possible damage that could occur under deadhead condition The inspectors again discussed this event with the licensee and reiterated the concern that the actions taken to resolve the issue did not appear to be appropriate. The inspectors determined that this problem had occurred previously. On Unit 3, operating procedure changes were made to prevent
operating two pumps in parallel during low flow conditions. No similar changes were made to Unit 1 and 2 procedure The inspectors reviewed the licensee's response to NRC Bulletin 88-04, Safety-Related Pump Los The response stated that the LPSW pumps were not susceptable to deadheading because the system was not operated with low flow conditions. The inspectors requested that the licensee review their response to this Bulletin in light of this even As of the end of this inspection period, the licensee had not determined how long the pump operated in a deadheaded condition or what flow rate was required to prevent this type of event from occurring in the futur The inspectors are concerned with the shared Unit 1 and 2 LPSW system, because the system has three LPSW pumps that all receive an auto start signal during an accident. Flow indication is not available in the control room, so operators cannot take immediate action to stop pumps if low flow exist The inspectors have expressed multiple concerns regarding the operation of the LPSW system. The licensee is currently performing a Design Basis Documentation (DBD)
review of the LPSW syste The inspectors will review the results of this DBD to ascertain if these concerns have been addresse d. Concentrated Boric Acid Storage Tank (CBAST) Boron Concentratio The inspectors reviewed the licensee's compliance with TS 3.2, High Pressure Injection and Chemical Addition Systems. TS 3.2.2 requires that one source per unit of concentrated soluble boric acid in addition to the borated water storage tank be available and operable, and states the source will be the concentrated boric acid storage tank containing at least the equivalent of 1100 cubic feet of 11,000 ppm boron as boric acid solutio Review of the CBAST boron sample results by the inspectors determined that boron concentration was less than 11,000 ppm for all three unit Discussions with the operators in the control room determined that CBAST level and boron concentration were maintained within the limits of an operating curve contained in operating procedure OP/0/A/1108/01, and that CBAST operability was based on meeting the requirements of the curv The operators stated that as long as the requirements of the curve were met, the CBAST contained the equivalent to 1100 cubic feet of 11,000 ppm boro The curve allowed a boric acid concentration of 4250 ppm if CBAST level was 130 inches. The inspectors held a discussion with the shift supervisor and were told that CBAST boron concentration had always been determined by the use of the operating curv The TS bases for TS 3.2 states that the quantity of boric acid in storage in the CBAST is sufficient to borate the reactor coolant system to a 1 percent delta K per K subcritical margin at cold conditions and that one 10 gpm boric acid pump would require approximately 12.7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br /> to inject the required boro The inspectors questioned how the licensee's operating curve meets the
requirements of TS 3. The inspectors consider that the word equivalent only applies to the effective volume of the CBAST (i.e.,
the CBAST must contain an effective volume of 1100 cubic feet) and not to the boron concentration required to be maintained. This item was discussed with the licensee and the licensee's position is that the operating curve is acceptable and that the word equivalent applies to both volume and concentratio The inspectors discussed this issue with the licensee on numerous occasions throughout the inspection period and requested that the licensee provide justification for the operating curv The only justification provided was a memo stating that the curve was equivalent to 1100 cubic feet of 11,000 ppm borated wate Just prior to the exit interview for this inspection period, the licensee agreed to provide a justification for their interpretation and to provide this'justification to the inspectors prior to April 25, 199 This issue is identified as Inspector Followup Item 269, 270, 287/92-09-01: CBAST Concer The inspectors also questioned the adequacy of the testing performed on the CBAST pumps to determine operability (paragraph 3.b).
e. Inadvertent Reactor Coolant System (RCS) Cooldown On March 5, 1992, while performing zero power physics testing, the licensee secured the 2B2 reactor coolant pump (RCP)
to allow a balancing shot installation on the pump. The reactor was critical in the intermediate range when the 2B2 RCP was secure Prior to securing the RCP, steam generator hot blowdown flow and RCS letdown flow were throttled to minimum flow in an attempt to prevent an RCS cool down when the pump was secured. When the 2B2 RCP was secured, the RCS began to cooldown from 531.8 degrees F. The operators then isolated 2MS17 and 2MS26 to isolate the turbine bypass valves and the RCS cooldown was stopped at 525.4 degrees F. The reactor remained critical throughout this even Subsequent to shift turnover, the 2B2 RCP was restarted and 2MS17 and 2MS26 were opened to allow primary heat transfer after restart of the 2B2 RC While the 2B2 RCP was secured, valves 2MS17 and 2MS26 had been cycled intermit tently to reduce RCS temperature as the RCS temperature increase Every time the valves were opened, the RCS cooled down. During this time period, the 2A steam generator feedwater startup block valve was also shut due to excessive seat leakage of the startup control valve and due to minimum feed flow alignmen When the 2B2 RCP was restarted and the turbine bypass block valves reopened, excessive seat leakage on the A steam header turbine bypass valves resulted in a cooldown. A reduction in steam generator level occurred for which the minimum feed flow valves could not compensat When steam generator level dropped below 21 inches for 30 seconds, the motor driven emergency feedwater (MDEFW)
pumps received an automatic start signal and started to maintain steam generator leve The feedwater system startup block valve was reopened to maintain
steam generator level and the MDEFW pumps were secure After securing the MDEFW pumps the operators observed that RCS temperature was less than 525 degrees F. The lowest temperature reached was 52 degrees F. The operators started driving rods in to ensure that the reactor was shutdown. They also notified the reactor engineer to run a shutdown margin calculation for an RCS temperature of 500 degrees The boron concentration required by the shutdown margin calculation was 1371 ppm, where as the RCS boron concentration was actually 1389 pp The licensee subsequently cycled the A side turbine bypass valves 25 percent opened and then closed, three times, to try to get the valves to reseat. The block valve was reopened after the valves reseate When the block valve was reopened RCS temperature did not decreas The inspectors discussed this item with licensee management and expressed concern regarding management's oversight of this evolutio The inspectors do not consider that the starting and stopping of reactor coolant pumps for maintenance activities while performing low power physics testing is appropriate under any circumstances but especially when known problems exist on the secondary side that result in transient The licensee was aware that stopping a RCP would result in a cooldow Upper Storage Tank Temperature Exceeds Procedural Limi On March 5, 1992, at approximately 5:30 p.m.,
the Unit 2 Upper Storage Tank (UST)
temperature exceeded the administrative limit of 130 degrees F and consequently the Emergency Feedwater System (EFDW)
was declared inoperabl The UST is the primary source of water for the EFDW system. A subsequent operability evaluation performed on the EFDW system determined that even though the UST temperature exceeded the procedural limit of 130 degrees F, the EFDW system would have adequately removed Reactor Coolant System (RCS)
decay heat during any potential transient that would have required the EFDW syste The event occurred when, due to secondary oxygen concentration considerations, steam flow to the feedwater heater was increase This increase in steam flow to the feedwater heater resulted in an increase in the UST temperature since the feedwater system was in the recirculation mode. The UST temperature increased from 118 degrees F to 134 degrees A statalarm was received at 125 degrees F and attempts were made to reduce UST temperature by throttling the steam supply to the feedwater heater and adding distilled water to the US However, the UST temperature increase did not turn around immediatel The UST temperature was brought back to within the procedural limits of 130 degrees F as required in Controlling Procedure For Startup, OP/2/A/1102/01, by 6:17 p.m. A notification to the NRC was made pursuant to 10 CFR 50.72 b.2. ii However, the notification was retracted following the operability evaluatio The licensee initiated a Problem Investigating Report (PIR)
to
determine the circumstances that led to this temperature increas The inspectors have questioned the alarm setpoint limit on UST temperature for the particular evolution during startup, the role of the operators during this evolution, as well as the amount of ongoing work in the control room that may have contributed to this even The licensee will be addressing these issues in the PI Based on the low safety significance as well as the licensee's planned corrective actions, this event will be classified as Non-Cited Violation 50-269, 270, 287/92-09-02: Failure to Follow Procedur This licensee identified violation is not being cited because the criteria specified in Section VII.B of the Enforcement Policy were satisfied. The inspectors will follow-up on this issue through the PI g. Turbine Driven Emergency Feedwater (TDEFW) Pump Testin During the Unit 2 restart, the inspectors determined that the TDEFW pump had not been tested using the main steam supply header prior to returning the unit to service. The TDEFW pump had been tested using the auxiliary steam supply header prior to returning the unit to servic The main steam supply was aligned to the TDEFW pump steam header; however, the pump was not considered operable on the main steam header because the pump had not been tested using the main steam supply. The inspectors determined that the pump had not been tested using the main steam supply due to the fact that a procedure change was required prior to testing the pump using the main steam heade This procedure change had not been processed prior to restarting the unit. The procedure change was required because the orifice in the pump miniflow line had been replaced with a bigger orific The change was made in response to the manufacturer's recommendations concerning flow requirements when the pump was operated at minimum flow conditions. The TDEFW pump was subsequently tested using the main steam header approximately 11 days after the RCS temperature was greaer than 250 degrees The inspectors questioned the acceptability of the auxiliary steam header as a qualified steam supply based on the fact that the auxiliary steam supply piping was not seismically qualifie The licensee performed an operability evaluation on the TDEFW pump to determine if the pump could be considered operable if the steam header was supplied only from auxiliary steam and concluded that the pump would still be operabl The operability determination concluded that the turbine driven EFW pump is only required to be operable during loss of offsite power or when the motor driven pumps are unavailable. T.S. 3.4.1 clearly states that the turbine driven
.pump must be operable when RCS temperature is above 250 degrees The licensee is reviewing this issue and will provide additional information for the residents' revie h. Inadvertent Reactor Protection System (RPS) Channel Actuatio On March 16, 1992, during performance of IP/1/A/305/3C, Unit 1 RPS Channel C On-line Test, instrument and electrical (I&E) technicians isolated a pressure switch on Unit 2 instead of Unit 1 causing RPS channel C on Unit 2 to actuat No reactor trip occurred due to the 2 out of 4 logic design-of the RP Two I&E technicians, one of them acting as an independent verifier were testing the "anticipatory reactor trip due to turbine trip" aspect of the RPS as required by Enclosure 11.4 of IP/1/A/305/3 The technicians proceeded to the Unit 2 turbine instead of the Unit 1 turbine and isolated pressure switch 2PS-410. Consequently, several alarms were received in the Unit 2 control roo The error was immediately recognized by the operators in the control room and the actuated RPS channel on Unit 2 was later reset after confirming the cause of the channel actuatio A maintenance incident report (MIR)
as well as a shift incident report (SIR) were generated. In addition, the technicians involved in this event were counseled on the significance of working on the correct uni Due to the low safety significance and no adverse consequences, as well as the licensee's corrective actions, this error of working on the wrong unit is considered as Non-Cited Violation 50-269/92-09-03:Failure to Follow Procedur This licensee-identified violation is not cited because the criteria specified in Section VII.B of the Enforcement Policy were satisfie Two non-cited violations were-identifie. Surveillance Testing (61726)
a. General 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 or witnessed in whole or in part:
PT/O/A/250/05 HPSW Pump and Power Suppl PT/2/A/251/03 CBAST Pump Tes Within the areas reviewed, licensee activities were satisfactor b. CBAST Pump Testin The inspectors reviewed PT/2/A/251/03, Concentrated Boric Acid Storage Tank (CBAST)
Pump Test, to determine compliance with the requirements of ASME Section X The inspectors determined that the procedure only requires that a discharge pressure of 65 psig is required to be obtained by throttling a valve in the test loop and that vibration data be take Review of the licensee'sSection XI program determined that the only required data is pump discharge pressure and vibratio The inspectors questioned the adequacy of the test performed on the CBAST pumps. The inspectors do not believe that the present test meets the requirements or intent of Section XI, in that, system resistance is varied to produce an acceptable discharge pressure each time the pumps are teste The test, as presently performed, only shows that the pump is developing flow and gives no indication of pump performance or degradation. The licensee agreed to review the pump performance testing conducted on the CBAST pumps to determine if the test methodology could be improved and to determine if the requirements of ASME Section XI are being adequately implemented. This item is identified as Inspector Followup Item 269, 270, 287/92-09-04: CBAST Pump Testing, and will be discussed in the next resident monthly repor No violations or deviations were identifie. 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:
MP/O/A/5050/39 10 year PM On 16 Cylinder SSF Diesel MP/O/A/1800/01 Tools and Materials Inventory Checklist On Open Safety Related Systems Within the areas reviewed, licensee activities were satisfactor No violations or deviations'were identifie. Inspection of Open Items (92700)(92701)(92702)
The following open items were reviewed using licensee reports, inspection, record review, and discussions with licensee personnel, as appropriate:
a. (Closed)
Violation 50-269/90-33-01:
Failure of Procedure PT/1/A/0204/07 to Adequately Incorporate the Licensee's Requirements for ASME Section XI Pump testin The licensee responded to this
violation by correspondence dated January 9, 199 The inspectors reviewed the licensee's corrective actions in response to this violation. The corrective actions included revising the procedure to reduce the allowable flow band and review of all pump testing procedures to ensure conformance with the licensee's flow band requirement b. (Closed)
LER 269/90-13: Valve Limit Switch Operation, Due to an Unknown Cause, Results in Condensate/Feedwater Transient and Reactor Trip. The inspectors reviewed the licensee's LER and the associated corrective actions to prevent reoccurrenc c. (Closed) LER 269/91-05:
Incorrect Flow Orifice Orientation Due to Installation Deficiency Causes Reactor Building Spray Trains to be Inoperable During Certain Accident Scenario The inspectors reviewed the licensee's completed corrective actions as well as planned corrective actions and found them to be adequat. Exit Interview (30703)
The inspection scope and findings were summarized on April 1, 1992, with those persons indicated in paragraph 1 abov The inspectors described the areas inspected, and discussed in detail the inspection findings. The licensee did not identify as proprietary any of the material provided to or reviewed by the inspectors during this inspectio During the exit interview, the resident staff discussed the startup events at lengt The events described in Sections 2.e and 2.f indicate the shift crews involved did not have full control of evolutions at all time The level of activity in the control room during low power physics testing concurrent with RCP evolutions appeared to be excessive at times and operators did not exercise their authority to reduce that leve Additionally, allowing questionable activities to proceed at the same time that difficulty in controlling plant conditions is being experienced does not indicate that all the command and control problems in the control room have been solve Item Number Description/Reference Paragraph 269,270,287/92-09-01 Inspector Followup Item - CBAST Concerns (paragraph 2.d).
269,270,287/92-09-02 Non-cited Violation - Failure to Follow Procedure For UST Temperature Control (paragraph 2.f)
269,270,287/92-09-03 Non-cited Violation -
Failure to Follow Procedure For RPS Testing (paragraph 2.h).
269,270,287/92-09-04 Inspector Followup Item - CBAST Pump Testing (paragraph 3.b).