ML20248A746
| ML20248A746 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 05/15/1998 |
| From: | Hernan R NRC (Affiliation Not Assigned) |
| To: | Scalice J TENNESSEE VALLEY AUTHORITY |
| References | |
| NUDOCS 9806010033 | |
| Download: ML20248A746 (5) | |
Text
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o May 15,1998 Mr. J. A. Scalice Acting Chief Nuclear Officer and Executive Vice President Tennessee Valley Authority 6A Lookout Place 1101 Market Street Chattanooga, TN 37402-2801 1
SUBJECT:
REVISIONS TO THE TECHNICAL SPECIFICATION BASES FOR THE SEQUOYAH NUCLEAR PLANT, UNITS 1 AND 2
Dear Mr. Scalice:
By letter dated November 8,1996, the Tennessee Valley Authority informed the U.S. Nuclear Regulatory Commission of changes made to the Sequoyah Technical Specification (TS) Bases.
The affected pages, B 3/4 3-2 and B 3/4 7-4 for each unit, identified the changes in the right margin as BR-9 and BR-10 for Unit 1 and BR-10 and BR-11 for Unit 2. The first change clarifies when an instrument channel must be declared inoperable with regard to being placed in trip for testing. Subsequently, this particular change was incorporated into the Bases Section as part of Amendment Nos 223 and 214 for Units 1 and 2 respectively, issued on April 21, 1997. Therefore, this letter only refers to revised page B 3/4 7-4 (change identified as BR-10 for Unit 1, and BR-11 for Unit 2), which shows the change that reflects a higher reservoir level assumed for balancing Essential Raw Cooling Water loads.
The purpose of this letter is to distribute the enclosed revised Bases pages 3/4 7-4 (one for each unit) to the appropriate TS manual holders.
Sincerely,
/s/
Ronald W. Hernan, Senior Project Manager
,/
Project Directorate 11-3 Division of Reactor Projects - 1/ll Office of Nuclear Reactor Regulation Oh/
Docket Nos. 50-327 and 50-328 1
Enclosures:
As stated cc w/ enclosures: See next page Distribution (w/ enclosure):
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"C" = Copy without attachment / enclosure "E" = Copy with attachment / enclosure "N" = No copy OFFICE PDil-3/PM q l
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NAME RHernan b/
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May 15, 1998
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Mr. J. A. Scalice Acting Chief Nuclear Officer and Executive Vice President Tennessee Valley Authority 6A Lookout Place 1101 Market Street Chattanooga, TN 37402-2801
SUBJECT:
REVISIONS TO THE TECHNICAL SPECIFICATION BASES FOR THE SEQUOYAH NUCLEAR PLANT, UNITS 1 AND 2
Dear Mr. Scalice:
By letter dated November 8,1996, the Tennessee Valley Authority informed the U.S. Nuclear Regulatory Commission of changes made to the Sequoyah Technical Specification (TS) Bases.
The affected pages, B 3/4 3-2 and B 3/4 7-4 for each unit, identified the changes in the right margin as BR-9 and BR-10 for Unit 1 and BR-10 and BR-11 for Unit 2. The first change clarifies when an instrument channel must be declared inoperable with regard to being placed in trip for testing. Subsequently, this particular change was incorporated into the Bases Section as part of Amendment Nos. 223 and 214 for Units 1 and 2 respectively, issued on April 21, 1997. Therefore, this letter only refers to revised page B 3/4 7-4 (change identified as BR-10 for Unit 1, and BR-11 for Unit 2), which shows the change that reflects a higher reservoir level assumed for balancing Essential Raw Cooling Water loads.
The purpose of this letter is to distribute the enclosed revised Bases pages 3/4 7-4 (one for each unit) to the appropriate TS manual holders.
l Sincerely, i
hi htWv-j Ronald W. Heman, Senior Project Manager Project Directorate 11-3 Division of Reactor Projects - 1/11 Office of Nuclear Reactor Regulation Docket Nos. 50-327 and 50-328
Enclosures:
As stated cc w/ enclosures: See next page l
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1
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e Mr. O. J. Zeringue SEQUOYAH NUCLEAR PLANT l
Tennessee Valley Authority
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cc:
Mr. J. A. Scalice, Senior Vice President Mr. Pedro Salas, Manager j
Nuclear Operations Ucensing and industry Affairs Tennessee Valley Authority Sequoyah Nuclear Plant i
6A Lookout Place Tennessee Valley Authority 1101 Market Street P.O. Box 2000 Chattanooga, TN 37402-2801 Soddy Daisy, TN 37379 i
Mr. Jack A. Bailey Mr. J. T. Herron, Plant Manager i
Vice President Sequoyah Nuclear Plant Engineering & Technical Services Tennessee Valley Authority Tennessee Valley Authority P.O. Box 2000 6A Lookout Place Soddy Daisy, TN 37379 1101 Market Street Chattanooga, TN 37402-2801 Regional Administrator U.S. Nuclear Regulatory Commission Mr. Masoud Bajestani Region 11 Site Vice President 61 Forsyth Street, SW.
Sequoyah Nuclear Plant Suite 23T85 Tennessee Valley Authority Atlanta, GA 30303-3415 P.O. Box 2000 Soddy Daisy, TN 37379 Mr. Melvin C. Shannon Senior Resident inspector Gentsral Counsel Sequoyah Nuclear Plant Tennessee Valley Authority U.S. Nuclear Regulatorv Commission ET 10H 2600 Igou Ferry Road 400 West Summit Hill Drive Soddy Daisy, TN 37379 Knoxville, TN 37902 Mr. Michael H. Mobley Director Mr. Raul R. Baron, General Manager Division of Radiological Health Nuclear Assurance 3rd Floor, L and C Annex Tennessee Valley Authority 401 Church Street 4J Blue Ridge Nashville, TN 37243-1532 1101 Market Street Chattanooga, TN 37402-2801 County Executive Hamilton County Courthouse Mr. Mark J. Burzynski, Manager Chattanooga, TN 37402-2801 Nuclear Licensing Tennessee Valley Authority 4J Blue Ridge 1101 Market Street Chattanooga, TN 37402-2801 i
PLANT SYSTEMS BASES 3/4.7.5 UITIMATE HEAT SINM WHS)
The limitations on UHS water level and temperature ensure that sufficient R83 cooling capacity is available to either 1) provide normal cooldown of the facility, or 2) to mitigate the effects of accident conditions within acceptable limits.
The limitations on the maximum temperature are based on providing a 30 R12 day cooling water supply to safety related equipment without exceeding their design basis temperature and is consistent with the recommendations of Regulatory Guide 1.27,
" Ultimate Heat Sink for Nuclear Plants", March 1974.
The limitations on minimum water level are based on providing sufficient flow to the ERCW serviced heat loads after a postulated event assuming a time.
R83 dependent drawdown of reservoir level.
Flow to the major transient heat loads (CCS and CS heat exchangers) is balanced assuming a reservoir level of elevation 670.
The time-independent heat loads (ESF room coolers, etc.) are balanced assuming a reservoir level of elevation 639.
BR-10 3/4.7.6 FLOOD PROTECTION The requirements for flood protection ensures that facility protective actions will be taken and operation will be terminated in the event of flood conditions.
A Stage 1 flood warning is issued when the water in the forebay is predicted to exceed 697 feet Mean Sea Level USGS datum during October 1 through April 15, or 703 Feet Mean Sea Level USGS datum during April 15 through September 30.
A Stage II flood warning is issued when the water in the forebay is predicted to exceed 703 feet Mean Sea Level USGS datum. A maximum allowed water level of 703 Mean Sea Level USGS datum provides sufficient margin to ensure waves due to high winds cannot disrupt the flood mode preparation. A Stage I or Stage II flood warning requires the imple-mentation of procedures which include plant shutdown.
Further, in the event of a loss of communications simultaneous with a critical combination flood, headwaters, and/or seismically induced dam failure the plan; will be shutdown und flood protection measures implemented.
3/4.7.7 CONTROL ROOM EMERGENCY VENTILATION SYSTEM The OPERABILITY of the control room ventilation system ensures that 1) the ambient air temperature does not exceed the allowable temperature for continuous duty rating for the equipment and instrumentation cooled by this system and 2) the control room will remain habitable for operations personnel during and following all credible accident conditioas.
The OPERABILITY of this system in conjunction with control room design provisions is based on limiting the radiation exposure to personnel occupying the control room to 5 rem or less whole body, or its equivalent.
This limitation is consistent with the requirements of General Design Criteria 19 of Appendix "A",
ANSI N510-1975 will be used as a procedural guide for surveillance testing.
SEQUOYAH - UNIT 1 B 3/4 7-4 Amendment No. 79 September 13, 1996
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PLANT SYSTEMS BASES 3/4.7.5 ULTIMATE HEAT SINK The limitations en the ultimate heat sink water level and temperature R70 ensure that sufficient cooling capacity is available to either 1) provide normal cooldown of the facility, or 2) to mitigate the effects of accident conditions.within acceptable limits.
The limitation on maximum temperature is based on providing a 30 day cooling water supply to safety related equipment without exceeding their design basis temperature and is consistent with the recommendations of Regulatory Guide 1.27,
" Ultimate Heat Sink for Nuclear Plants", March 1974.
The limitations on minimum water level are based on providing sufficient flow to the ERCW serviced heat loads after a postulated event assuming a time dependent drawdown of reservoir level.
Flow to the major transient heat loads R70 (CCS and CS heat exchangers) is balanced assuming a rcservoir level of el. 670.
The time independent heat loads (ESF room coolers, etc.) are balanced assuming a reservoir level of el. 639.
lBR-11 1
3/4.7.6 FLOOD PROTECTION The requirements for flood protection ensures that facility protective actions will be taken and operation will be terminated in the event of flood conditions.
A Stage 1 flood warning is issued when the water in the forebay is i
predicted to exceed 697 feet Mean Sea Level USGS datum during October 1 through April 15, or 703 Feet Mean Sea Level USGS datum during April 15 through September 30.
A Stage II flood warning is issued when the water in the forebay is predicted to exceed 703 feet Mean Sea Level USGS datum. A maximum allowed water level of 703 Mean Sea Level USGS datum provides sufficient margin to ensure waves due to high winds et +ot disrupt the flood mode preparation. A Stage I or Stage II flood warning requires the implementation of procedures which inc'.ude plant shutdown.
Further, in the event of a loss of communications simultaneous with a critical combination flood, headwaters, and/or seismically inducua dam failure the plant will be shutdown and flood protection measures implemented.
3/4 7.7 CONTROL ROOM EMERGENCY VENTILATION SYSTEM i
The OPERABILITY of the control room ventilation system ensures that 1) the ambient air temperature does not exceed the allowable temperature for continuous duty rating for the equipment and instrumentation cooled by this system and 2) the control room will remain habitable for operations personnel during and following all credible accident conditions. The OPERABILITY of this system in conjunction with control room design provisione is based on limiting the radiation exposure to personnel occupying the control room to 5 rem or less whole body, or its equivalent. This limitation is consistent with the requirements of General Design Criteria 19 of Appendix "A",
ANSI N510-1975 will be used as a procedural guide for surveillance testing.
1 SEQUOYAH - UNIT 7 B 3/4 7-4 Amendment No. 70 September 13, 1996 1