ML18153A093

LER 96-008-00:on 961112,water Gas Decay Tank Oxygen Analyzer Pressure Sensors Inoperable Due to Vendor Supplied Equipment Not Meeting Procurement specifications.Post-implementation Procedures Revised & Transducers replaced.W/961212 Ltr

ML18153A093
Person / Time
Site:	Surry
Issue date:	12/12/1996
From:	Christian D VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:
References
96-628, LER-96-008-01, LER-96-8-1, NUDOCS 9612190135
Download: ML18153A093 (7)

Text

{{#Wiki_filter:e e 10CFR50.73 Virginia Electric and Power Company Surry Power Station 5570 Hog Island Road Surry, Virginia 23883 December 12, 1996 U. S. Nuclear Regulatory Commission Serial No.: 96-628 Document Control Desk SPS:mdk Washington, D. C. 20555 Docket No.: 50-280 Docket No.: 50-281 License No.: DPR-32 License No.: DPR-37

Dear Sirs:

Pursuant to Surry Power Station Technical Specifications, Virginia Electric and Power Company hereby submits the following Licensee Event Report applicable to Surry Power Station Units 1 and 2. REPORT NUMBER 50-280/50-281 /96-008-00 This report has been reviewed by the Station Nuclear Safety and Operating Committee and will be forwarded to the Management Safety Review Committee for its review. Very truly yours, D. A. Christian Station Manager Enclosure \I :/' i pc: Regional Administrator 101 Marietta Street, NW, Suite 2900

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I Atlanta, Georgia 30323 R. A. Musser _NRG Senior Resident Inspector Surry Power Station 1

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l':(RC FORM366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY 0MB NO. 3160-0104 (4-95)

               '                                                                                                         EXPIRES 4130/98 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS MANDATORY INFORMATION COLLECTION REQUEST: 50.0 HRS.

REPORTED LESSONS LEARNED ARE INCORPORATED INTO THE LICENSEE EVENT REPORT (LER) LICENSING PROCESS AND FED BACK TO INDUSTRY. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE INFORMATION AND RECORDS MANAGEMENT BRANCH (T-6 F33), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555-0001, AND TO (See reverse for required number of digits/characters for each block) THE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503. FACILITY NAME (1) DOCKET NUMBER (2) PAGE(3) SURRY POWER STATION, Unit 1 05000-280 1 OF6 TITLE (4) Waste Gas Deg3y Tank Oxyqen Analvzer Pressure Sensors lnooerable EVENT DATE 6) LER NUMBER (6 REPORT DATE 17 OTHER FACILITIES INVOLVED 181 MONTH DAY YEAR YEAR SEQUENTIAL REVISION MONTH DAY YEAR FACILITY NAME DOCKET NUMBER NUMBER NUMBER Surrv Unit 2 05000 - 281 FACILITY NAME DOCKET NUMBER 11 12 96 96 -- 008 -- 00 12 12 96 05000 - OPERATING THIS REPORT IS SUBMITIED PURSUANT TO THE REQUIREMENTS OF 10 CFR:(Check one or more) (11) MODE (9) N 20.2201 (b)' 20.2203(a)(2)(v) X 50.73(a)(2)(i) 50. 73(a)(2)(viii) POWER 20.2203(a)(1) 20.2203(a)(3)(i) 50.73(a)(2)(ii) 50. 73(a)(2)(X) LEVEL (10)100'!1 20.2203(a)(2)(i) 20.2203(a)(3)(ii) 50.73(a)(2)(iii) 73.71 20.2203(a)(2)(ii) 20.2203(a)(4) 50.73(a)(2)(iv) OTHER 20.2203(a)(2)(iii) 50.36(c)(1) 50.73(a)(2)(V) Specify in Abstract below and 20.2203(a)(2)(iv) 50.36(c)(2) 50. 73(2: ::; :vii) or in NRC Form 366A LICENSEE CONTACT FOR THIS LER 1121 NAME D. A. Christian, Station Manaqer I(804r365~200 t 1 9 Area Code) COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13\ CAUSE SYSTEM COMPONENT MANUFACTURER REPORTABLE CAUSE SYSTEM COMPONENT MANUFACTURER REPORTABLE TO TONPRDS NPRDS SUPPLEMENTAL REPORT EXPECTED (14) I EXPECTED I MONTH DAY YEAR I Clf YES ves comclete EXPECTED SUBMISSION DATA I NO I SUBMISSION DATE (16) I I ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines) (16) On November 12, 1996, with Unit 1 and Unit 2 both at 100% power, an instrument technician performing calibration activities during Waste Gas Holdup System oxygen analyzer testing determined that the associated pressure transducer operating range was improper for the existing design. The vendor was contacted and confirmed that the existing pressure transducer was inappropriate for the application and would result in a non-conservative error in the indicated oxygen concentrations. As a result, the oxygen analyzers were not operable and the compensatory sampling was not conducted as required by Technical Specification Table 3.7-S(a). The health and safety of the public were not affected by this event. A radiological release has not occurred. The oxygen concentration within the Waste Gas Holdup System did not exceed allowable limits. This event was caused by vendor supplied equipment that did not meet procurement specifications that went undetected during receipt inspection and post installation testing. The -pressure transducers - and . associated software were replaced, and the instrumentation calibrated and tested satisfactorily. To prevent recurrence, a vendor representative was present and assisted in the corrective action, and the calibration and test results were forwarded to the vendor's laboratory for confirmation of proper functioning of the instruments. The expectations for receipt inspection and adequate post installation testing will be re-emphasized. This report is being made pursuant to 10CFRSO. 73(a)(2)(i)(B). NRC FORM (4-95)

NRC FORM366 (4-95)

• LICENSING EVENT REPORT (LER)
• U.S. NUCLEAR REGULATORY COMMISSION Text Continuation FACILITY NAME (1) DOCKET LER NUMBER (6) PAGE(3)

YEAR SEQUENTIAL NUMBER REVISION NUMBER SURRY POWER STATION, Unit 1 05000-280 96 008 00 2 of 6 TEXT Of more space is required. use additional copies of NRC Form 366A) (17)

1.0 DESCRIPTION

OF THE EVENT The Waste Gas Holdup System [EIIS:WE] is a shared system supporting degassing operations for Units 1 and 2. The oxygen analyzers [EIIS:MON] are used to provide the control room operator with oxygen concentration readings in the Waste Gas Holdup System during degassing operations to the waste gas decay tank.. The oxygen analyzers provide local indication at the analyzer, input to the main control room annunciator alarm, and input to the main control room chart recorder. There are no automatic functions associated with this system. If oxygen concentrations increase to unacceptable levels in the Waste Gas Holdup System, manual operator action is taken to reduce the oxygen concentration to acceptable limits precluding the development of an explosive gas mixture in the Waste Gas Holdup System .

  . During July 1996 a design modification to the Waste Gas Holdup System oxygen analyzers subsystem was implemented to enhance the operability of the oxygen analyzer subsystem through improved reliability of the oxygen analyzer sample compressors.                                             This design modification, in part, changed the operating pressure of the oxygen analyzer subsystem.                                         By design, the new configuration placed the oxygen analyzers sensing chambers in a subatmospheric condition. During design change development, vendor documentation for the existing pressure transducers [EIIS:TD] in the oxygen analyzer subsystem was reviewed and determined to be adequate for the new configuration. The design modification was implemented and analyzer 1-GW-AIT-1508 was placed in service on August 7, 1996. Analyzer 1-GW-AIT-150A was placed in service on September 10, 1996.

On November 12, 1996 an instrument technician was troubleshooting spurious annunciator alarms from an out of service Waste Gas Holdup System oxygen analyzer, 1-GW-AIT-1508. During performance of calibration activities the instrument technician determined that the pressure transducer appeared to have an improper range for the application. The system operating pressure ranged from a positive pressure to a subatmospheric pressure while the NRC Form 366A (4-95)

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.* NRC FORM366 (4-95)

• LICENSING EVENT REPORT (LER)
• U.S. NUCLEAR REGULATORY COMMISSION Text Continuation FACILITY NAME (1) DOCKET LER NUMBER (6) PAGE(3)

YEAR SEQUENTIAL NUMBER REVISION NUMBER SURRY POWER STATION, Unit 1 05000 -280 96 008 00 3 of6 TEXT Of more space is required, use additional copies of NRC Form 366A) (17) pressure transducer's range was O to 200 psig. Further investigations, an engineering review of the system design and operating history, a review of vendor documentation, and communications with the ~ender determined that the pressure transducers in both oxygen analyzer circuits were not compatible with the current system operation. These investigations determined that the pressure transducer would not function under subatmospheric pressures __ thoLJgh the oxygen concentration readings would change with pressure variations. Consequently, the oxygen analyzer microprocessor would not pressure compensate the oxygen concentration readings during those periods when the pressure transducer's chamber was below atmospheric pressure since the pressure transducer generated a negative input value to the microprocessor. Oxygen analyzer operation under these conditions would result in non-conservative oxygen concentration readings. A review of the operating history was performed to determine when degassing operations were conducted with the oxygen analyzers in service with the improper pressure transducers. The results of this review determined that analyzer 1-GW-AIT-1508 had been in service for approximately 26 days from August 7, 1996 through September 2, 1996. Analyzer 1-GW-AIT-150A had been in service on three occasions for approximately eleven days from September 16,

      - 1996 through September 27, 1996, eight days from October 22, 1996 through October 30, 1996, and eleven days from November 1, 1996 through November 12, 1996. During these periods, the oxygen analyzer was operating at subatmospheric pressures, resulting in non-conservative oxygen concentration readings,- and*theTechnical-Specifications Table 3.7-5(a) requirement for oxygen analyzer operability was not satisfied.                                       The compensatory sampling required by Technical Specifications was not conducted since the oxygen analyzers were believed to be operable.

NRC Form 366A (4-95)

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NRC FORM366 (4-95) e LICENSING EVENT REPORT (LER)

                                                                                                        -  U.S. NUCLEAR REGULATORY COMMISSION Text Continuation FACILITY NAME (1)                                           DOCKET                  LER NUMBER (6)            PAGE(3)

YEAR SEQUENTIAL NUMBER REVISION NUMBER SURRY POWER STATION, Unit 1 05000 -280 96 008 00 4 of 6 TEXT(~ more space is required, use additional copies of NRC Form 368A) (17) A review of indicated readings and sample results determined that the oxygen concentration in the Waste Gas Holdup System did not exceed allowable limits during this event. Explosive gas concentrations did not exist during this event. This event is reportable in accordance with 10CFRS0.73(a)(2)(i)(B) for any operation or condition prohibited by Technical Specifications. 2.0 SIGNIFICANT SAFETY CONSEQUENCES AND IMPLICATIONS There are no safety consequences or implications associated with this event. A radiological release did not occur. A review of the results from local sampling of the Waste Gas Holdup System determined that allowable limits were not exceeded. The data from the oxygen analyzer recorders was collected and analyzed using conservative vendor supplied correction factors. This analysis confirmed that the Technical Specification oxygen limits were met during the time the oxygen analyzers were in service with the improper pressure transducers. A review of the radiological concentrations within the Waste Gas Holdup System determined that throughout this event radiological limits were not exceeded. Upon discovery of the improper pressure transducers, local sampling as specified in Technical Specifications, was performed to ensure oxygen concentrations would not exceed allowable limits. Local sampling continued throughout the corrective action process while the condition was corrected. 3.0 CAUSE OF THE EVENT This event was caused by vendor supplied equipment that did not meet procurement specifications that went undetected during receipt inspection and post installation testing. In 1992, the vendor provided -documentation that replacement pressure transducers and microprocessor programming covered an operating range of O to 1O bars, as requested in the procurement specifications. This range was appropriate for the design change implemented in 1996. During troubleshooting of the 1996 design modification, it was identified that the pressure transducers and microprocessor programming adjustments made in 1992 were not accurate below one bar. System operation below one bar resulted in non-pressure compensated oxygen II concentration readings. NRC Form 366A (4-95)

NRC FORM366 (4-95)

• LICENSING EVENT REPORT (LER) e U.S. NUCLEAR REGULATORY COMMISSION Text Continuation FACILITY NAME (1) DOCKET LER NUW -'"R (6) PAGE(3)

YEAR SEQUENTIAL NUMBER REVISION NUMBER SURRY POWER STATION, Unit 1 05000 -280 96 008 00 5 of 6 TEXT (If more space is required, use additional copies of NRC Form 366A) (17) 4.0 IMMEDIATE CORRECTIVE ACTION Upon discovery of the improper pressure transducers in the oxygen analyzer subsystem, the instrument technician notified the Instrumentation and Controls Supervisor and submitted a Deviation Report. The operating shift declared the oxygen analyzers inoperable and conservatively initiated local sampling at the frequency specified in the Technical Specifications allowed action statement. Local sampling at the sp~cified frequency continued throughout the corrective action process. The System Engineer was notified and the oxygen analyzer vendor contacted. A request for engineering assistance was submitted to evaluate corrective actions. 5.0 ADDITIONAL CORRECTIVE ACTIONS The vendor was contacted and confirmed that the existing pressure transducers were inappropriate for subatmospheric application and would result in a non-conservative error in the indicated oxygen concentrations. A change to the design package was developed in accordance with 10 CFR 50.59 and the improper pressure transducers were replaced and the microprocessor programming was adjusted. Post implementation testing procedures were revised to include verification of proper analyzer performance at subatmospheric pressure conditions. 6.0 ACTIONS TO PREVENT RECURRENCE A vendor representative was brought on site and oversaw the replacement of the pressure transducers and made programming adjustments to the oxygen analyzer microprocessor. The test results and calibration data were reviewed and forwarded to the vendors laboratory for confirmation of proper functioning of the instrumentation, including the pressure compensation function. The vendor confirmed proper functioning of the instrumentation on November 21, 1996. The expectations for receipt inspection and adequate post installation testing will be re-emphasized. NRC Form 366A (4-95)

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II, NRC FORM 366

• It U.S. NUCLEAR REGULATORY COMMISSION (4-95)

LICENSING EVENT REPORT (LER) Text Continuation FACILITY NAt.1E (1) DOCKET LER NUMBER (6) PAGE(3) YEAR SEQUENTIAL NUMBER REVISION NUMBER SURRY POWER STATION, Unit 1 05000 - 280 96 008 00 6 of6 TEXT Of more space is required, use additional copies of NRC Form 366A) (17) 7.0 SIMILAR EVENTS There were no similar events identified. 8.0 ADDITIONAL INFORMATION None. NRC Form 366A (4-95)}}