ML20059D204
| ML20059D204 | |
| Person / Time | |
|---|---|
| Site: | Braidwood  |
| Issue date: | 07/31/1990 |
| From: | Hunsader S COMMONWEALTH EDISON CO. |
| To: | Murley T Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20059D208 | List: |
| References | |
| NUDOCS 9009060151 | |
| Download: ML20059D204 (8) | |
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, Commonnealth Edison -
, , _ 72 West Acams Stroet. CNcago, lihnos ,
.. \ Address Reply to. Post Othc0 Box 767 CNeago,Ilkros 60690 0767 y
July,31, 1989' l
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l Dr. Thomas E. Murley, Director .
I l Office of Nuclear Reactor Regulation j
, U.S. Nuclear Regulatory Commission Washington, DC 20555 Attn: Document Control'resk, I
Subject:
Braidwood Station Units 1 and 2 Application for Amendment to Tacility Operating Licenses NPF-72 and NPF-77 Appendix A, Technical Specifications t NRC Docket Nos. 50-456 and 50-4S7
Dear Dr. Murley:
Pursuant to 10 CTR 50.$0, Commonwealth Edison (Edison) proposes to amend Appendix A, . Technical Specifications, of Facility Operating' Licenses NPF-72 and NPF-77. The proposed scendment requests changes to Technical Specification 3.3.3.3 to provide a new location of the free field seismic monitor'for the time-history accelerograph. The current location of the' monitor is 39 + 00E and 41 + OOS. The proposed new location of the monitor is 38:+ 01S and 34 + 15E.
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 and Off-site review in accordance with Edison precedures.
At Braidwood Station, four triazial accelerometers are' installed that individually measure the absoluto acceleration as.a function of' time in three orthogonal directions. (See Attachment B for-a description'of the monitors and L their locations). These monitors have a +2g to O to -29 range with a 0.0005V full !
l scale resolution. The cross axis sensitivity is 0.0005 /g, 9 accordingly. Three of these accelerometers are installed on the containment and have the capability to' l; sense and transmit data in the event that the containment floor accelerometer ,
l senses a 0.02g force. The fourth monitor is the free field monitor. A fifth,- 1 totally. Independent monitor remains operable in the Essential Service Water (SX)
- pump room. It is as sensitive as the other four monitors but is presently set to activate more conservatively at less than or equal to .029 force. During the time that the free field seismic monitor is being moved and, as such, will be ;
inoperable, the remaining three triasial accelerometers, and the SX pump room monitor will continue to be operable. These remaining-operable monitors 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.
9009060151 900731 PDR ADOCK 05000456
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Dr., T.M. Murley -
2 - July 31, 1989
. Tochnicc1 Sp3cification 3.3.3.3 stotos that with ono or msro of tho required seismic monitors inoperable for more than 30 days, prepare and submit a special 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 I 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 " administratively inoperable" until the Technical Specification Amendment is received. Since the proposed snendment cannot be r9asonably issued within the 30 days following the disablement of the monitor, Edist'n will forward a special report to the commission as required, outlining the situation and the plans to restore the monitor to OPERABLE status in the new propcsed location. Because other monitors remain operable, as described above, ad9quate seismic monitoring capability exists during this period. This is also addressed in Attachment B.
Edison's proposed amendment request is subdivided as follows:
- 1. Attachment A gives a s nt'ary of the changes proposed in the snendment including pleitclal 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 CTR 50.92(c), which has determined that no significant hazards considerations exist.
- 4. Attachment D 1:sludes the marked-up Technical Specification pages with the requested changes indicated.
Edison is notifying the State of Illinois of this application for amendment by transmitting a copy of this letter and its attachments to the designated State Official.
Please direct any questions you may have concerning this submittal to this office.
Very truly yours, l (. f _
S.C. Hunsader J u Nuclear Licensing Administrator l
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/sc1:0218T 1-2 l Att.'s: A) Summary of Proposed Changes B) Safety Evaluation and Environmental Assessment C) Evaluation of Significant Hazards 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
AIIACHMENT.A.
-l SIDE (ARY_Or. PROPOSED CHANGES TO APPENDIX A TECHNICAL SPECITICATIONS Or ,
FACILITY ' OPERATING LICENSES NPF-72 AND NPr.77
-l 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+00S. 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 7
field monitor is 38+015 and 34+15E. i i
The vendor (Terra Technology, Inc.) recommendations state that the free field monitor be located a minimum of 200 to 250 feet from any heavily 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 the center line of Braidwood Station entrance road, and over 400 feet from the Braidwood Station Turbine Building outerwall (the nearest major structure).
Two photographs are enclosed to show the current and proposed location of the free field monitor. These are provided as Enclosures 1 and 2.
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- s ATTACHMENT B SAFETY EVALUATICDI AND ENVIRONMENTAL ASSESSMENT FOR PROPOSED CHANGES TO APPENDIX A' TECHNICAL SPECIFICATIONS OF EACILITY OPERATING LICENSES NPF-72 AND NPF-77 SAFETY EVALUATION in(Loduction The purpose of the seismic instrumentation is to insure that sufficient-
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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 design 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 saismic event loads into the structures via computerised 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. Byron /Braidwood UFSAR Section 3.7.4 describes the functiJns of the seismic instrumentation including the time-history accelerograph to which the free fleid seismic monitor of' interest is connected.
Time History Accelerocraph The time-history accelerograph is the master control unit for all control-timing signals and system data interface. It continually monitors and has the ability to digitize voltage signals and record on magnetic tape both pre- and post-seismic event data. Integral to-the accelerograph are two triasial 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 art two time-history accelerographs utilised as part of l 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 l 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 Braidwood is provided at' i elevation 338 feet 0 inch in the auxiliary building on the column row 18 wall l adjacent to the column line "L" wall. . This accelerograph is a self-contained unit l independent of the other accelerograph. The response spectrum for this' location can be determined using the playback unit and response spectrum analyser.
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ATTACHMINT B fcontinvidl The first time-history.accelerograph is connected to four trianial
?ccelerometers, each of which measures the absolute acceleration as a function of tice in three orthogonal directions. These directions coincide with the major axes ,
of t.5e analytical model of the structure. These accelerometers are placed at the folloving locations:
- 1. In the free field, currently at site coordinate 39+00E and 41+00S, to be moved to site coordinate 38+c?S and 34+15E,
- 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 '.efueling floor at olevation 426 feet.
l The safe shutdown value for Braidwood Station is 0.2 9 As such, the l configuration of the seismic monitor syatem conforms to that addressed in l Regulatory Guide 1.12 and ANSI Standard .N18.5 for a= plant with safe shutdown acceleration of less than or equal t o ;9.3' g. Also, the soil and subsurface '
conditions a4 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 rigure 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.
- . Control Room Operator Notification The centrally located seismic indicating and recording equipment near the main control room is the source of the operator information concerning the acknowledgement of an earthquake. An acceleration of 0.02g 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 analyzer (see UFSAR Section 3.7.4.2.4), an operator can observe the triaxial cpectral analysis from the containment building slab monitor l.
and the auxiliary building 426 feet elevation monitor. (The latter monitor is direct-connected to the spectrum analyser, while the former monitor is connected to ,
the analyser through the time-history accelerograph.)
The operator can also use the playback feature of the system to obtain time history and spectral analysis of any of the recorded monitors.
1 Summary (
Safety related equipment and features will be unaffected by the placement of the-free field monitor. The proposed. change to the free fleid monitor location conforms to the guidance given in Reg Guide 1.12 and ANSI N18.5. Adequate monitoring capability will continue to exist.to^ assess the affects of a seismic event on equipment and features important to safety, both during and after L relocation of the free fleid monitor, SCH/sc1:0218T 5
& =am a ATTACMMENT B (continued)
ENVIRONMENTAL ASSESSMENT Edison has evaluated the proposed amendment against the criteria for and
{ identification of licensing and regulatory actions requiring environment assessment l
In accordance with 10CTR51.21. It has been determined that the proposed change meets the criteria.for a categorical exclurlon 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 a:.d the change involves changes to the use of components located within the restricted area, and it involves no significant hazard considerations. There are no changes in the type or enounts of effluents related Off-site, and there is no significant l increase in individual or cumulative occupational radiation exposure.
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-ATTACHMENT C EVALUATION OF_ SIGNIFICANT ~ HAZARDS CONSIDERATICMS FOR PROPOSED CHANCES j TO APPENDIX . A TECHNICAL SPECIFICATIONS OF l i
[AC11JTLQEERATING LICENSES NPF-72 AND NPF-77 I Commonwealth Edison has evaluated this proposed unendment and determined- '
that it involves no significant hasards considerations. According to 10 CTR.
50.92(c), a proposed unendment to an operating license involves no significant hazards considerations if operation.of the facility in accordance with the proposed amendment would not I
- 1. Involve a significant; increase in the probability or consequences of i an accident previously evaluated; or t
- 2. Create the possibility of a new or different kind of accident from -j any accident previously evaluated; or
- 3. Involve a significant' reduction in a margin of safety. I A. !
The proposed chance does not involvt_a_glanificant increase in the probability or consequences of an accident oreviously evaluated. .i 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 f ashion .to a seismic event regardless of pre-monitor
' location. As a result, .the proposed change does aot result in a significant increase in the probability or-consequences of accidents previously evaluated, i B. The oronosed changes does not create the prossibility of a new or different i Lind of neeldent from any accident o_reviousiv evaluated.
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 free field monitor will not be significantly different at the proposed new location as compared toilts current location. The proposed location for the free field monitor does not impact the operability of any equipment required for safe operation of the plant during normal or accident conditions. As such, the proposed change does not create the possibility for a new or different kind of accident from those previously evaluated.
C. The proposed chance does not involve a sionificant reduction in a maroin of safety. '
l The operation of the' seismic monitoring system is not taken credit for in any accident analysis described in the UTSAR. The relocation of the seismic l
monitor does not affect any accident analysis. As such, the proposed change 'f does not involve a reduction in.the margin to safety..
SCH/sc1:0218T:7
i ATTACHMENT D MARKED +UP PAGES FOR PROPOSED CF1ANGES TO APPENDIX A TECHNICAL SPECIFICATIONS OF I TACILITY OPERATING LICENSES NPT-72 AND NPT-77 )
s REAIDWOOD STATION Revised Pagest 3/4 3 B3/4 3-4 i
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