IR 05000424/1999002

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Insp Repts 50-424/99-02 & 50-425/99-02 on 990214-0320. Violations Noted.Major Areas Inspected:Operations, Engineering,Maint & Plant Support
ML20205Q350
Person / Time
Site: Vogtle  Southern Nuclear icon.png
Issue date: 04/15/1999
From:
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:
Shared Package
ML20205Q337 List:
References
50-424-99-02, 50-424-99-2, 50-425-99-02, 50-425-99-2, NUDOCS 9904210181
Download: ML20205Q350 (10)


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U. S. NUCLEAR REGULATORY COMMISSION (NRC)

REGIONll I

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Docket Nos. 50-424 and 50-425 License Nos. NPF-68 and NPF-81 l

Report No:

50-424/99-02 and 50-425/99-02 i

Licensee:

Southern Nuclear Operating Company, Inc.

Facility:

Vogtle Electric Generating Plant Units 1 and 2 Location:

7821 River Road Waynesboro, GA 30830 l

Dates:

February 14 through March 20,1999 Inspectors:

J. Zeiler, Senior Resident inspector K. O'Donohue, Resident inspector W. Kieinsorge, Maintenance Inspector (Section M2.1)

D. Forbes, Radiation Specialist (Section R1)

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Approved by: P. Skinner, Chief

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Reactor Projects Branch 2

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Division of Reactor Projects l

Enclosure

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EXECUTIVE SUMMARY Vogtle Electric Generating Plant Units 1 and 2 NRC Inspection Report 50-424/99-02 and 50-425/99-02 This integrated inspection included aspects of licensee operations, engineering, maintenance, and plant support. The report covers a five-week period of resident inspection and inspections in the area of Maintenance and Health Physics by region based inspectors.

Operations In general, the conduct of operations during major evolutions of the Unit 1 refueling

outage 1R8 was satisfactory. Management was involved in the daily activities, especially various contingency plans which included management walkdowns. Good controls and control room attention were noted when the unit entered a planned fueled midloop condition (Section 01.1).

Operator actions to initiate a manual reactor trip of Unit 2 were appropriate following the

inadvertent closure of a main feedwater isolation valve. The failure to follow the independent verification procedure resulting in the inadvertent closure of the Unit 2 loop 3 main feedwater isolation valve was identified as a violation of 10 CFR 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings (Section O1.3).

e Improper feedwater heater level maintenance and non-conservative calibration of feedwater flow computer input resulted in two examples where reactor core thermal power violated license condition 2(C). During one instance, the magnitude and duration above the licensed thermal power limit was caused by operator deficiencies in following abnormal operating procedures (Section 08.1).

Enaineerina The licensee's failure to identify the Unit 2 sequencer as inoperable in a timely manner e

resulted in a violation of Technical Specifications (TS) 3.3.2 (Section E8.1).

Report Details

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Summary of Plant Status Unit 1 operated at full power until February 14,1999, at which time the licensee commenced a coast down for the eighth refueling outage (1R8). On February 27, a shutdown to begin 1R0 was initiated from 87 percent power. At 18.5 percent power, a manual reactor trip was initiated due to non-conservative Intermediate Range Nuclear instrumentation readings. At the end of the inspection period, the unit was in Mode 5 with preparations for Mode 4 in progress.

Unit 2 operated at full power until February 19, at which time the licensee commenced a reduction in power to 28 percent in order to take the turbine-generator offline to replace a generator stator cooling flow strainer. On February 20, the generator was connected to the grid and the unit returned to 100 percent power on February 21. On March 2, a manual reactor trip was initiated following the inadvertent closure of a main feedwater isolation valve due to a personnel error installing a Unit 1 outage clearance. Following corrective actions, a reactor startup was initiated and full power operation was attained on March 4.

1. Operations

Conduct of Operations 01.1 General Conduct of Operations Durina Unit 1 Refuelina Outaae 1R8 (71707)

The inspectors conducted frequent reviews of ongoing refueling outage activities.

These activities included the unit shutdown and entry into Modes 4,5 and 6. In addition, core offload, fuel assembly sipping, core reload, core verification, and re-entry into Mode 5 were reviewed.

The inspectors noted management involvement in the daily activities. Pre-job briefings were performed consistently, frequently led by a manager. When the unit entered a planned fueled midloop condition, the licensee limited other outage activities to ensure that operational focus remained on the midloop condition. The inspectors also noted management involvement with the various contingency plans developed for periods of high shutdown risk activities and that the contingency plans of ten included management walkdowns. The inspectors concluded that control room performance was enhanced due to the level of management involvement.

O1.2 Unit 1 Manual Reactor Trio durina Shutdown for 1R8 a.

Inspection Scoce (71707) ( 93702)

The inspectors reviewed the manua' reactor trip that was initiated during the Unit 1 shutdown to begin refueling outage 1R8 b.

Observations and Findinas On February 27, Unit 1 was being shutdown to begin refueling outage 1R8. As power was reduced, the operators noted that the intermediate range nuclear instrurnentation was reading high in comparison to the power range instrumentation. A concern was j

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raised that the intermediate range high flux trip (25 percent) may not reset before the Power Range (P-10) reset setpoint occurred which would automatically unblock the intermediate range channei trips. After discussions with management, a decision was made to manually trip the reactor. At 11:40 p.m., following an evolution pre-briefing, the reactor was tripped at 18.5 percent power. Post-trip plant response was normal with no significant complications identified.

The inspectors reviewed the post-event and sequence of events logs and noted no significan. abnormalities. The inspectors witnessed the conduct of the event review team meetings and concluded that these activities were appropriately performed. The I

licensee determined that the intermediate range instrumentation channels were working properly and the higher indication at end of core life than at beginning of core life for a given power level was an expected phenomenon. A calibration is generally not l

l performed on the intermediate channels during the operating cycle to account for the power distribution profile changes that result in higher indicated flux levels toward end of life reactor operation. During the shutdown for refueling outage 2R6, a similar overlap concern was identified Reactor engineering personnel were aware of the potential for inadequate intermediate to power range instrument overlap.

With the installation of Gamma Metrics Neutron Flux Monitoring System during this outage, the intermediate channels can be adjusted during the operating cycle to account for these changes. During the upcoming Unit 2 shutdown for refueling outage 2R7, the licensee plans to adjust the intermediate range channels, if necessary, prior to initiation of the shutdown to ensure that a similar condition does not occur.

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Conclusions The inspectors concluded that the decision to manually trip the unit was prudent.

Although the licensee was aware of the potential for inadequate overlap between the immediate range and power range instruments, no calibrations were performed to preclude this potential overlap condition.

01.3 Unit 2 Manual Reactor Trio Due to inadvertent Closure of a Main Feedwater Isolation Valve a.

Inspection Scope (71707)(93702)

The inspectors reviewed the circumstances for a Unit 2 manual reactor trip on March 2.

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Observations and Findinas A manual reactor trip of Unit 2 was initiated following the inadvertent closure of the loop 3 main feedwater isolation valve (MFIV). The plant response to the trip was normal with no significant complications identified.

The MFIV c'osed when two plant equipment operators (PEOs) erroneously remosed control power fuses to the Unit 2 loop 3 MFIV instead of the intended Unit 1 valve. The inspectors reviewed clearance 19915714 documentation for removing the Unit 1 MFIV from service and determined that it was clear and precise with respect to specific

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component identification and required actions. The inspectors also determined there was no indication of ambiguity in the instructions provided to the PEOs regarding which unit was to be affected. The work control supervisor had directed the use of a second qualified person to verify the proper implementation of this clearance. The licensee determined that the root cause of the error was poor self-checking and verification by the PEOs.

The licensee planned to implement several corrective actions which included briefings I

on the self-verification process, lessons learned training on the event in licensed and l

non-:! censed operator classes, a plant evaluation to identify areas and processes where l

similar wrong unit human performance errors could occur, revise the concurrent l

verification policy to require 3-way verbalization of complete equipment tag numbers, and require operations and maintenance management to increase field observation of activities to reinforce management expectations on proper self-verification.

l The inspectors reviewed procedure 00308-C, Verification Policy, Revision 11, which provides the methods for verifying correct performance of activities that affect the alignment of safety-related components. Section 4.2.2 prescribed the performance of concurrent verification and required that the " positioner" and " verifier" must independently read the clearance and correctly identify the component to be manipulated. Contrary to the requirements of procedure 00308-C, the PEOs failed to identify the correct MFIV fuses on Unit 1 and erroneously pulled the Unit 2 MFIV fuses

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resulting in the manual trip. The inspectors determined that the failure to follow i

procedure 00308-C constituted a violation of 10 CFR 50, Appendix B, Criterion V, I

instructions, Procedures, and Drawings. This Severity Level IV violation is being treated l

as a Non-Cited Violation (NCV) 50-425/99-02-01, " Failure to Follow Verification I

Procedure Results in MFIV Closure and Manual Reactor Trip," consistent with Appendix

C of the NRC Enforcement Policy. This violation is in the licensee's corrective action program as Event Report 2-99-001.

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Conclusions The inspectors concluded that the operator's action to initiate a manual reactor trip of Unit 2 was appmpriate following the inadvertent closure of the loop 3 main feedwater isolation valve. The failure of PEOs to properly verify that they were on the correct

equipment prior to removing fuses to the Unit 2 MFIV was identified as a NCV.

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Miscellaneous Operations issues (92901)

08.1 (Closed) Unresolved item (URI) 50-424/98-10-01: Review of Unit 1 Overoower Event The inspectors reviewed Event Report 1-98-001 which documented the licensee's investigation of this event. The direct cause of the initiating event was attributed to online calibration of the 4B feedwater heater level transmitter under maintenance work l

order (MWO) 19801128. During the work planning for this MWO, work planners l

identified that the 4A and 4B feedwater heaters did not allow bypassing of the controlling level transmitter while it was being calibrated. However, work planners failed to ensure that these feedwater heater level transmitters were removed from the MWO. When the technicians removed the 4B feedwater heater level transmitter from service, a false high

water level signal was generated csusing the 4B feedwater heater to automatica'ly isolate. Neither the technicians performing the work, nor operations personnel wr.c authorized the work, recognized the potential impact on 48 feedwater level control. The licensee determined that this, in part, was attributed to inadequate maintenance and control room briefings.

The licensee's planned corrective actions included briefing all work planners on the event, emphasizing the need for thorough work order reviews of online work, review of lessons learned from this event, and conduct pre-briefing seminars to emphasize the expectations of material covered in these briefings.

When the 4B feedwater heater isolated, the reactor operator reduced turbine load about 4 percent and inserted control rods several steps in anticipation of the expected reactor power increase from the colder feedwater. After these initial actions, the operating crew did not reduce reactor power by any substantial amount for about 50 minutes. The licensee identified numerous factors that contributed to the operators' response. These included the operators' failure to recognize that lower reactor coolant system (RCS)

temperature caused indicated Power Range Nuclear instrument (PRNI) readings to be less than actual reactor power; ineffective crew communications between the Shif t Supervisor (SS) and Unit Shift Supervisor (USS) which resulted in a 30 minute delay in using RCS loop differential temperature to control reactor power; Abnormal Operating Procedure (AOP) 18016-C, Condensate and Feedwater Malfunction, Revision 11, was confusing regarding the power indication to monitor since thermal power indication was inaccurate and there were no cautions or warnings that the PRNis will not be accurate when RCS tempera'ure was below normal; and the lessons learned from a Unit 1

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overpower transient on February 25,1997, were not effective in preventing this event.

The licensee identified numerous corrective actions to enhance operator response.

Some of the major corrective actions included training on lessons learned and operator instrymentation and secondary response knowledge deficiencies with all operators in reos "kation Mning, management and supervisory monitoring of effective 3-way comniunications in the control room, enhance AOP 18016-C for more effective response to this type of event, evaluate and improve if necessary the simulator response to feedwater heater transients, and add more simulator training on loss of feedwater heating transients.

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License Condition 2(C) of the Vogtle Unit 1 Facility Operating License NPF-68, authorizes the licensee to operate the unit at reactor core power levels not in excess of 3565 megawatts thermal (100 percent). The inspectors determined that this issue

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constituted a violation of License Condition 2(C), in that, between 11:32 p.m. and 12:26

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a.m., on December 29,1998, reactor core rated thermal power exceeded 3565

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megawatts thermal following a feedwater temperature transient that was initiated by improper feedwater heater level transmitter maintenance. Reactor power peaked at 103.85 percent power and frequently exceeded 102 percent power during the transient period. This Severity Level IV violation was identified as an example of NCV 50-424, 425/99-02-02," Licensed Power Limit Exceeded Due to improper Maintenance Activities

- Multiple Examples, consistent with Appendix C of the NRC Enforcement Policy. This violation is identified in the licensee's corrective action program as Event Report 1-98-00.

ll. Maintenance M2 Maintenance and Material Condition of Facilities and Equipment M2.1 inservice inspection (ISI) (73753)

The inspectors evaluated the licensee's ISI program and the ISI program's implementation. The inspectors concluded that the procedures reviewed were concise l

and well written. Inservice examinations observed or reviewed were conducted in

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accordance with p,operly approved procedures, by qualified examiners using calibrated equipment and certified materials.

M8 Miscellaneous Maintenance issues (92700) (92902)

M8.1 (Closed) Licensee Event Report (LER) 50-425/98-10-00: Reactor Overpower Event Followina Instrument Calibration This LER involved the non-conservative calibration of a feedv.ater flow computer point input to the reactor power calculation. Following the calibration activity, reactor power was increased slightly to the new indicated 100 percent power level. The condition existed for five days. The licensee determined that reactor power had actually operated at an average power of 100.12 percent during the five day period in violation of Facility Operating License NPF-81, Section 2C, which requires that the licensed reactor thermal power limit not be exceeded. This violation of NRC regulatory requirements was identified as an example of NCV 50-424,425/99-02-02," Licensed Power Limit Exceeded Due to Improper Maintenance Activities - Multiple examples," consistent with Appendix C of the NRC Enforcement Policy. This violation is in the licensee's corrective actions program as LER 50-425/98-10-00.

111. Enaineerina E8 Miscellaneous Engineering issues (92700)(92903)

E8.1 (Closed) LER 50-425/98-09-00: Seauencer inoperability Leads to Operation Outside of Technical Specification The Inspectors reviewed the LER, and condition reports (CRs) 219980557 and 219980559. The inspectors noted that the LER stated the cause of the event was ".an inability to interpret the initial conditions that caused the alarm and their impact on sequencer operability." Because neither the LER nor the CRs included additional training, the inspectors questioned the adequacy of the corrective actions. Interviews with operations personnel revealed that system engineers were assumed to be experts on their assigned systems. Therefore, the system ec,gineer assigned to the Engineered Safety Features Actuation System (ESFAS) soquencer was assumed to have detailed knowledge about the operation of the ESFAS sequencer. However, the inspectors determined that the ESFAS system engineers had only received general training provideu to all system engineers and operators on the operation of the ESFAS sequencer. As a result of insufficient knowledge or training, the system engineer provided incorrect information which operations personnel used to determine that the

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personnel used to determine that the ESFAS sequencer was operable. The licensee revised CR 219980557 to include sequencer training for the system engineers.

TS 3.3.2, Condition C, required that the inoperable ESFAS train be restored to operable status in 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> or place the unit in Mode 3 within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and be in Mode 5 within 42 hours4.861111e-4 days <br />0.0117 hours <br />6.944444e-5 weeks <br />1.5981e-5 months <br />. Since Train B ESFAS Sequencer was r ot returned to operable status within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> nor the unit placed in Mode 3 within twelve hours, Unit 2 was operated in a condition prohibited by Technical Specifications. This Severity Level IV violation is being treated as NCV 50-425/99-02-03, " Sequencer inoperability Leads to Operation Outside f

of Technical Specifications," consistent with Appendix C of the NRC Enforcement Policy.

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This violation was in the licensee's corrective action program as LER 50-425/98-09-00 and CR 219980557.

IV. Plant Support R1 Radiological Protection and Chemistry (RP&C) Controls R1.1 Tour of Radioloaical Protected Areas (83750)

During tours of the Radiological Control Area (RCA), the inspectors reviewed saey data and observed activities in progress. Radiological surveys reviewed were well documented. The licensee had effectively posted radiological areas and radioactive material observed was labeled as required. Locked High Radiation Aieas were controlled as required by licensee procedures. Calibrations for "in use" direct radiation instrumentation, frisking monitcrs, whole body counters, and air sampler instrumentation were current for those instruments observed.

Selected Radiation Work Permits (RWPs) were reviewed. The inspectors noted that appropriate protective clothing arW dosimetry were required. During plant tours adherence of workers to the RWP requirements was verified. The inspectors noted efforts to reduce personnel contaminations during the Unit 1 outage had been aggressive. As of March 12,1999, the licensee had documented approximately 30 Personnel Contamination Reports.

The inspectors reviewed and discussed with the licensee representatives the program for testing and qualifying breathing air as Grade D. Breathing air met Grade D or better quality requirements. All respiratory protection equipment observed during facility tours was being maintained in a satisfac;ory condition.

R1.2 Occupational Radiation Exposure Control Proaram (83750)

The inspectors reviewed the licensee's implementation of radiation protection principles to achieve occupational doses and doses to members of the public As Low As Reasonably Achievable (ALARA).

The inspectors review of the licensee's ALARA program determined that the !!censee had established an aggressive Unit 1 outage goal of 114 person-rem. The i!:ensee had tracked and trended outage exposures for purposes of future outage pluning. Outage maintenance briefings observed focused on dose reduction efforts and contamination

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control practices. The inspectors also observed the effective use of communication equipment se,h as microphones, cell phones, and camera coverage of containment and refueling floor work to minimize worker exposures. Health physics personnei debriefed workers to incorporate lessons learned into the ALARA program and the ALARA suggestion program had resulted in ALARA program improvements being implemented.

The inspectors noted that collective dose continued to trend downward based on these ALARA initiatives. The inspectors concluded that the ALARA program continued to be effective in controlling overall collective dose. All personnel radiation exposures during 1999 to date were below regulatory limits.

V. Manaaement Meetinos and Other Areas X1 Exit Meeting Summary The inspectors presented the inspection results to members of licensee management at the conclusion of the inspection on March 19, and April 13,1999. The licensee acknowledged the findings presented.

j PARTIAL LIST OF PERSONS CONTACTED

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Licensee

R. Brown, Manager, Training and Emergency Preparedness W. Burmeister, Manger Engineering Support S. Chesnut, Plant Operations Assistant General Manager G. Frederick, Manager Operations J. Gasser, Nuclear Plant General Manager K. Holmes, Manager Maintenance P. Rushton, Plant Support Assistant General Manager M. Sheibani, Nuclear Safety and Compliance Supervisor C. Tippins, Jr., Nuclear Specialist i A. Maze, NDE Process Supervisor SNC INSPECTION PROCEDURES USED IP 71707:

Plant Operations IP 73753 Inservice Inspection IP 83750:

Occupational Exposure IP 92700:

Onsite Followup of Written Reports of Nonroutine Events at Power Reactor Facilities IP 92901:

Followup - Operations IP 92902:

Followup - Maintenance / Surveillance IP 92903:

Followup - Engineering IP 93702:

Prompt Onsite Response to Events at Operating Power Reactors

ITEMS OPENED AND CLOSED ITEM NUMBER TYPE DESCRIPTION l

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Closed 50-425/99-02-01 NCV Failure to Follow Verification Procedure

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l Results in MFIV Closure and Manual i

Reactor Trip (Section 01.3)

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50-424/98-10-01 URI Review of Unit 1 Overpower Event (Section l

08.1)

50-425/99-02-02 NCV Licensed Power Limit Exceeded Due to improper Maintenance Activities - Multiple Examples (Sections 08.1 and M8.1)

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50-425/98-10-00 LER Reactor Overpower Event Following l

Instrument Calibration (Section M8.1)

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50-425/98-09-00 LER Sequencer Inoperability Leads to Operation Outside of Technical Specifications (Section E8.1)

50-425/99-02-03 NCV Sequencer Inoperability Leads to Operation Outside of Technical Specifications (Section E8.1)

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