ML20247N188

Application for Amends to Licenses NPF-72 & NPF-77,changing Tech Spec 3.3.3.3 to Provide New Location of Free Field Seismic Monitor for time-history Accelerograph

ML20247N188
Person / Time
Site:	Braidwood
Issue date:	07/31/1989
From:	Hunsader S COMMONWEALTH EDISON CO.
To:	Murley T NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), Office of Nuclear Reactor Regulation
Shared Package
ML20247N191	List: ML20247N188 ML20247N205
References
NUDOCS 8908020321
Download: ML20247N188 (8)

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[p =wg}; 72 West Adams Street, Chicago, (thnois e

.e Commonwealth Edison i

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) Xddress Reply to: Post OThee Box 767

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%d. Chicago, Illinois 60690 a 0767 y

July.31,'1989 Dr.l Thomas E. Murley, Director, Of fice -of Nuclear Reactor Regulation L

U.S. Nuclear Regulatory Commission l

' Washington, DC 20555 Attn Document Control Desk

Subject:

Draidwood Station Units 1 and 2 Application for Amendment to Facility Operating Licenses NPF-72 and NPF-77 Appendix A, Technical Specifications NRC Docket Nos. 50-456 and 50-457 Dear Dr. Murley

' Pursuant to 10 CFR 50.90, Commonwealth Edison (Edison) proposes to amend

' Appendix A, Technical Specifications, of Facility Operating Licenses NPF-72 ano NPT-77.

The proposed amendment requests changes to Technical Specification 3.3.3.3 to provide e new location of the, free field seismic monitor for the time-history accelerograph. The current location of the monitor is 39 + OOE and 41 + OO.S.

The proposed new location of the monitor is 38 + O1S and 34 + 15Z.

This relocation is being made due to the construction of a new Training Building in the area that includes the current monitor location. This work started on July 24, 1989.

The proposed amendment has been reviewed and approved by Edison On-site end Off-site review in accordance with Edison procedures.

At Braidwood Station, four triaxial accelerometers are' installed that individually measure the absolute acceleration as a function of time in three orthogonal direction %

(Eee Attachmenc.B for a description of the monitors and

.their Iw ations). Tnese monitors have a +27 to O to -29 range with a 0.0005% full acale' resolutions The cross axis I,ensitivity is 0.0005 /g, accordingly, ihree of 9

these acceleroineters are instelled on tie containment and have the capability to sence and transmit. data in the event that the containment ficor accelerometer senses a 0.027 force. The fonrth moultor is the free f.ield monitor. A fifth, totally 3ndependent monitor remains operabic in the Essential Service '/eter -(SX) pump room.

It is as'nonsitive as the other teur monitors but is presently set to

-activate more conservatively at less than or equal to.02g force. During the time that the free field seismic monitor; it being moved and, as such, W113 be inoperable, the remaining three triaxial accelerometers, and the SK pump room monitor.will continue to be operable. "leso remaining operable menitors will be in a condition to provide the data necessary to access the impact of any seismic events on plant' systems and structures to allow for safe operation of the plant.

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D'r. T.M. Murley July 31, 1989 Technical Specification 3.3.3.3 states that with one or more of the required seismic monitors inoperable for more than 30 days, prepare and submit a speci'al report to the commission, pursuant to Specification 6.9.2, within the next "10 days outlining the cause of the malfunction and the plans for restoring the instrument (s) to OPERABLE status.

The 30 day limiting condition for operation (LOCAR) for the free field monitor was entered on July 24, 1989. The free field monitor is being physically moved to the new location, but will be functional and available for service by August 11, 1989. At that time, the free field monitor will be " administrative 1y inoperable" until the Technical Specification Amendment is received.

Since the proposed amendment cannot be reasonably issued within the 30 days following the disablement of the monitor, Edison will forward a special report to the commission as required, outlining the situation and the plans to restore the mon 3 tor to OPERABLE status in the new proposed location. Because other monitors remain operable, as described above, adequate seismic monitoring capability exists during this period. This is also addressed in Attachment B.

Edison's proposed m,endment request is subdivided as follows:

1.

Attachment A gives a summary of the changes proposed in the mnendment including pictorial views that show the new location of the monitor with respect to the old location.

2.

Attachment B provides the Safety Evaluation and Environmental Assessment.

3.

Attachment C describes Edison's evaluation performed in accordance with 10 CFR 50.92(c), which has determined that no significant hazards considerations exist.

4.

Attachment D includes the marked-up Technical Specification pages with the requested changes indicated.

Edison is notifying the State of 111xnois of this application. for swendment by transmitting a ecpy of this letter and its attachments to the designated State Official.

Please direct any questions you may have concerning this r.utaittal to this office.

Very tru3y yours, b

S.C. Hunsader Nuclear Licensing Administrator

/sc1: J21dTil-2 Att.'s:

A) Summary of Proposed Changes B) Safety Evaluation and Environmental Assessment C) Evaluation of Significant Hazaids Considerations D) Marked-up Technical Specification Pages

Enclosures:

1,2 and 3 cc:

Resident Inspector-Braidwood S.P.

Sands-NRR J. Hinds-Region III M.C.

Parker-IDNS

A*1"fACID4ENU l

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SUMMARY

OF PROPOSID_Q{ ANDES TO APPENDIX A l

IECHNICAL SPECIFICATIONS OF l

FACILITY OPE)ATING LICEUSES NPF-72 AND NPF-77 The proposed changes to Technical Specification 3.3.3.3 indicate the new location of the free field seismic monitor. Due to the construction of a new Training Building in the area that includes the free field seismic monitor, it must be relocated. The current coordinates of the free field monitor are 39+00E and 41+005.

This location is approximately 250 feet south of the southwest corner of the Braidwood Station protected area fence. The proposed new location of the free field monitor is 38+01S and 34+15E.

l The vendor (Terra Technology, Inc.) recommendations state that the free field monitor be located a minimum of 200 to 250 feet from any he0vily travelled roads or major structures.

In accordance with these recommendations, the proposed location for the free field monitor will place it 294 feet west of uhe center line of Braidwood Station entrance road, and over 400 feet from the Braicwood Station Turbine Building outerwall (the nearest major structure).

Two photographs are enclosed to show the current and proposed location of the free fleid monitor. These are provided as Enclosures 1 and 2.

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AZIACHMENT B lu SAIETY EVALUATION AND ENVIRONMENTAL ASSESSMENT FOR PROPOSED CHANGES e

IQ_AEEgliDIX A TECHNICAL SPECIFICATIONS OF EACRITY OPERATING LICENSES NPF-72 ANJ_JIPF-77 SAFETY EVALUATLQH

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Introduction l

The purpose of the seismic instrumentation is to insure that sufficient capability is available to promptly determine the magnitude of a seismic event, and evaluate the response of features important to safety. This comparison is necessary in order to compare the magnitude of the event to the decign basis event to determine if a plant shutdown is required.

The seismic instrumentation utilizes two types of sensor-recorders, with a

' playback capability available in the control room area.

The location and function of these seismic devices were selected to provide, adequately, for the determination of seismic event loads into the structures via computerized analysis programs. The system is maintained during a loss of ac power by a backup de power supply. Loss of ac power operation is alarmed locally and in the main control room.

Dyron/Braidwood UFSAR Section 3.7.4 describes the functions of the seismic instrumentation including the time-history accelerograph to wh,.ch the free field seismic monitor of interest is connected.

Time History Accelerograpjl The time-history accelerograph is the master control unit for all control timing signals and system data interface.

It continually monitors and nas the ability to digitize voltege signals and reccrd on magnetic tape both nre-and post-seismic event data.

Integral to the accelerograph are two triaxial seismic triggers which provide a signal to actuate a local alarm on the seismic warning panel during a seismic event. These trigger inputs are continually monitored by the accelerograph. There are two time-history accelerographs utilized as part of the seismic instrumentation.

The time-history accelerograph located in the auxiliary electric equipment room receives inputs from four triaxial monitors, each of which measures the absolute acceleration as a function of time in three orthogonal directions. These directions coincide with the major axes of the analytical model of the structure.

The second time-history accelerograph and its monitor at Draidwood is provided at elevation 338 feet 0 inch in the auxiliary building on the column row 18 wall adjecent to the column line "L" s3 3.

This accelerograph is a snif-contained unit i

1 independent of the other accelerog7:6pn. The responce spectrum for this locaticn can be determined using the playback unit and response spectntm analyzet.

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ATTACHMENT B (continued)

The first time-history accelerograph is connected to four triaxial

' accelerometers, each of which measures the absolute acceleration as a function of l

time in three orthogonal directions. These directions coincide with the major axes of the analytical model of the structure. These accelerometers are placed at the following locations:

1.

In the free field, currently at site coordinate 39+00E and 41 005, to be moved to site coordinate 38+01S and 34+15E, L

2.

on the containment building foundation slab at elevation 377 feet and azimuth 145 degrees, 3.

on the containment shell wall at elevation 502 feet and azimuth 145 degrees, and 4.

on the containment refueling floor at elevation 426 feet.

The safe shutdown value for Braidwood Station is 0.2 g.

As such, the configuration of the seismic monitor system conforms to that addressed in-Regulatory Guide 1.12 and ANSI Standard N18.5.for a plant with safe shutdown acceleration of less than or equal to 0.3 g.

Also, the soll and subsurface conditions a( Braidwood Station are relatively uniform.

(This is discussed in UFSAR Section 2.5.4 and is graphically depicted by UFSAR Figure 2.5-21.

A copy of Figure 2.5-21 is provided as Enclosure 3.)

Thus, the response of the free field monitor to seismically induced ground motion will not be altered by the monitor's change in location.

Cnntrol Room Operator Notification The centrally located seismic indicating and recording equipment near the main control room is the source of the operator infonnation concerning the acknowledgement of an earthquake.

An acceleration of 0.029 in any direction activates the seismic switch which turns on the seismic monitors and lights up the the seismic alarm lights at the seismic warning panel.

Using the spectrum ana?.yrer (see UFSAR Section 3.7.4.2.4), an operator can observe the triaxial spectral ana]ysis from the containment building slab monitor and the auxiliary building 426 feet elevation monitor.

(The latter monitor is direct-connected to the spectrum analyzer, while the former monitor is connected to the analyzer through the time-hictory accelerograph.)

The operator can also use the playback feature of the system to obtain time history and spectral analysis of any of the recorde~ monitors.

SMLm_Ary Gafety related egnipment and features will be unaffected by the pincement of the free field monitor. Tha proposed change to the free field monitor location conforms to the guidance given in Rog Guide 1.12 and ANSI N18.5.

Adequate monitoring cepability will continue to exist to assess the affects of a seismic event en equipment and featurcs important to safety, both during and efter relocation of the free field monitor-SCH/sc1:021BT 5

ATTACHMEfC B (continued)

ENVIRONMENT 1b ASSESSMENT Edison has evaluated the. proposed amendment against the criteria for and identification of Ilcensing and regulatory actions requiring environment assessment

.In accordance with 10CFR51.21. It has been determined that the proposed change meets the criteria for a categorical exclusion as provided for under 10CTR51.22(c)(g). This determination was based on the fact that this change is-being proposed as an amendment to a license issued pursuant to 10CTR50 and the change involves changes to the use of components located within the restricted area, and it involves no significant hazard considerations. There are no chariges in the type or amounts of effluents related Off-site, and there is no significant increase in individual or cumulative occupational radiation exposure.

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ATTACIEENI._.C EVALUATION OF SIGNIFICANT HAZARDS CONSIDERATIONS FOR PR_QEOSED CHANGES ID APPENJIX A TECIMICAL SPICIfifATIONE_QI EACILITY OPEEATING LICIHSIS NPF-72 AND MPF-77 Commonwealth Edison has evaluated this proposed amendment and determined that it involves no significant hazards considerations. According to 10 CFR 50.92(c), a proposed amendment to an operating license involves no significL7t hazards considerations if operation of the facility in accordance with the proposed amendment would not:

1.

Involve a significant increase in the probability or consequences of an accident previously evaluated; or 2.

Create the possibility of a new or different kind of accident from any accident previously evaluated; or 3.

Involve a significant reduction in a margin of safety.

A.

The proposed change does not_inynlye a significant inc re r_s e in the probability nr consequences of an_mssident pIrviously evaluateA The relocation of the seismic monitor has no impact on the probability for accidents or seismic events. Equipment and plant features important to safety will respond in the same fashion to a seismic event regardless of pre-monitor location. As a result, tht proposed change dccs not result in a significant increase in the probability or consequences of accidents previously evaluated.

B.

The proppsed_changea_does nnt create the pIsssibility of a new or dif ferent 122d of accident fIom any accident previously evalua.teh The seismic monitors are not active components taken credit for in any accident analysis. The purpose of the monitors is to provide information regarding the magnitude of a seismic event. This information would then be used to assess any impact on continued operation of the facility. The soil and subsurface conditions at Braidwood Station are relatively uniform. Thus, the response of the ~.ree field.onitor will not be significantly different at the proposed new location as compared to its current location. The proposed location for the f ree field monitor does not ir. pact the operability of any l

equipment required for safe operation of the plant during normal or accident l

conditions. As such, the proposed change does not create the possibility for a new or different kind of accident from those I eviously evaluated.

C.

The_ proposed changA_dags not invol"e a significant reduct2on in a matgin_n1 E.ALRiya The operation of the seismic monitoring system is not taken credit for in any accident analysis described in the UFSAR. The relocation of the seismic monitor does not affect any accident analysis. As such, the proposed change does not involve a reduction in the margin to safety.

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ATTACHMENT D MARKED =11P_PAGES_ffR PESPDSID CHANGES TO AEPENDIX A IECIRufAL SPECIFICATIONS OE EACILITY OPERATING LICENSES NPF-72 AND Nff-77 ERAIL) WOOD STATION Revised Pages:

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