3F0896-25, Special Rept:On 960712,declared Seismic Monitoring Instrumentation Inoperable for More than 30 Days.Caused by Triaxial Peak Accelographs Failures.Instruments Will Be Omitted from FSAR Section 2.5.4.4

Special Rept:On 960712,declared Seismic Monitoring Instrumentation Inoperable for More than 30 Days.Caused by Triaxial Peak Accelographs Failures.Instruments Will Be Omitted from FSAR Section 2.5.4.4

ML20117F533
Person / Time
Site:	Crystal River
Issue date:	08/28/1996
From:	Beard P FLORIDA POWER CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
3F0896-25, 3F896-25, 96-03, 96-3, NUDOCS 9609040113
Download: ML20117F533 (3)

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":m'a August 28, 1996 3F0896-25 U. S. Nuclear Regulatory Commission

. Attention: Document Control Desk Washington, D. C. 20555-0001

Subject:

Special Report No. 96-03

Dear Sir:

Attached is Special Report 96-03 which is submitted in accordance with Florida Power Corporation's (FPC) Final Safety Analysis Report Section 2.5.4.4. This report discusses inoperable seismic monitoring instrumentation.

FSAR Section.2.5.4.4 requires a Special Report to be submitted when one or more seismic monitoring instruments is inoperable for more than 30 days. This report was not submitted as required by the FSAR and is considerably overdue. The attached report describes some of the circumstances which contributed to FPC's failure to recognize the FSAR commitment and provide a Special Report as required. A root cause evaluation of this error is being conducted under FPC's corrective action program for Problem Report PR 96-0229 which initiated this report.

Sincerely,

[

P. M. Beard, Jr.

Senior Vice President Nuclear Operations PMB/TWC Attachment xc: Regional Administrator, Region II Project Manager, NRR Senior Resident Inspector MM 9609040113 960828 PDR ADOCK 05000302 S PDR CRYSTAL RIVER ENERCY COMPLEX: ss7eo w Po un. si e c<v.iw no nond. 3442s-e70s e assa) 7es-o4se ,

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U.S. Nuclear Regulatory Commission 3F0896-25 Page 2 of 3 SPECIAL REPORT 96-03 SEISMIC MONITORING INSTRUMENTATION IN0PERABLE FOR GREATER THAN 30 DAYS DESCRIPTION OF OCCURRENCE On April 4,1994, during Refueling Outage 9, maintenance personnel were informed by systems engineering that Triaxial Peak Accelographs located at the top of the Reactor (SI-4-MEI) and at the top of "A" Once Through Steam Generator [0TSG) (SI-5-MEI) were not required to be checked for operability in accordance with the applicable refueling interval performance test procedure PT-379 " Equipment Check of the Triaxial Peak Recording Accelerometers". This information was based on the disposition of a Request for Engineering Assistance (REA) which recommended abandoning these instruments. This disposition erroneously stated that there was no CR-3 commitment requiring these accelographs. As noted below, these instruments are addressed in Section 2.5.4.4 of the Final Safety Analysis Report (FSAR) which requires procedures to be in place to qualitatively assess, functionally test, and calibrate this instrumentation. On July 12, 1996, FPC determined the failure to perform PT-379 during Refuel 9 and again during Refuel .

10 led to a failure to restore the instrumentation to operable status, and I generated Problem Report PR 96-0229 which also identified the need for this Special Report. l l

I BACKGROUND In March,1994 the description of the seismic instrumentation was relocated from  !

CR-3's Standard Technical Specifications (TS) to Section 2.5.4.4 of the FSAR as part of CR-3's implementation of the Improved Technical Specifications (ITS).

FPC committed to retain the relocated requirements in their entirety and change i them, if desired, using the 10CFR50.59 process. Initially, the requirement to

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submit a Special Report within 10 days if one or more of the instruments is 1 inoperable for more than 30 days was not included in the FSAR description as part of the ITS conversion process, although PT-379 did contain the requirement from the previous TS Required Action. The FSAR was revised in December, 1994 to include the requirement for the Special Report.

CAUSE OF MALFUNCTION i l

SI-4-MEI and SI-5-MEI are located in a harsh environment with temperatures at the high end of the rated range for these accelographs. As a result, they have experienced a history of failures when channel checks have been performed.

Additionally, the background vibration at these locations makes any information that may be gained from the instruments difficult to evaluate. The above-mentioned REA stated that relocation of the instruments would supply additional information should an earthquake occur for comparison of the measured response with CR-3's design basis, but that the information would not be of significantly greater value than that supplied by the remaining accelographs located in less harsh environments.

O .*

U.S. Nuclear Regulatory Commission '

3F0896-25 Page 3 of 3 ANALYSIS The bases of the technical specification which was transferred to FSAR Section 2.5.4.4 stated that the seismic monitoring instrumentation was consistent with the recommendations of Safety Guide 12 " Instrumentation for Earthquakes", March 1971. Safety Guide 12 states, in addition to strong motion triaxial '

e accelographs, that peak recording accelographs could be installed on other selected Category I structures, systems and components to verify the seismic response determined analytically from the traces recorded by the strong motion accelographs. The Safety Guide explains that this "other" instrumentation could provide data which would justify the application of less conservatism than might t be needed in the absence of such measured data in evaluating the possible effects  !

on the plant caused by an earthquake. Not having data provided from SI-4-MEI and SI-5-MEI would require CR-3 to determine analytically, the seismic effects on Category I structures, systems and components in a more conservative manner. In addition, any actual seismic acceleration should be significantly less than those reflected in CR-3's piping analyses which are based on extremely conservative seismic input.

The following additional seismic monitoring instruments and sensor locations ,

provide sufficient information to meet the intent of Safety Guide 12:

Triaxial Time-History Acccelographs '

Containment Vessel Foundation Outside Containment on Top of Ring Girder Control Room Floor l Triaxial Peak Accelographs Top of Borated Water Storage Tank (BWST)

Triaxial Seismic Switches Containment Vessel Foundation PLANS TO RESTORE' INSTRUMENT (S) TO FUNCTIONAL STATUS FPC plans to abandon SI-4-MEI or SI-5-MEI in place. A modification package has been generated to accomplish this action and includes the necessary justification in accordance with 10CFR50.59. Upon approval of the modification, a change to FSAR Section 2.5.4.4 will become effective omitting these instruments from the FSAR.

The root cause evaluation for Problem Report PR 96-0229 will determine (1) why the REA disposition failed to recognize the regulatory commitment associated with the accelographs and (2) why the reporting requirements were not transferred to the FSAR during the ITS conversion. Also, the controls in place to ensure other such former TS commitments are captured, and that appropriate personnel are aware of these commitments will be evaluated.

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