ML20247M566
| ML20247M566 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 05/14/1998 |
| From: | De Agazio A NRC (Affiliation Not Assigned) |
| To: | Zeringue O TENNESSEE VALLEY AUTHORITY |
| References | |
| GL-96-06, GL-96-6, TAC-M96784, TAC-M96785, TAC-M96786, NUDOCS 9805260299 | |
| Download: ML20247M566 (4) | |
Text
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3 Mr. O. J. Zeringue May 14, 1998
)
Acting Chief Nucle:r Officer 4
and Executive Vice President Tennessee Valley Authority l
6A Lookout Place j
1101 Market Street Chattanooga, Tennessee 37402-2801
SUBJECT:
REQUEST FOR ADDITICNAL INFORMATION - GENERIC LETTER 96-06, ASSURANCE OF EQUlf MENT OPERABILITY AND CONTAINMENT INTEGRITY DURING DESIGN BASl3 ACCIDENTS (TAC NOS. M96784, N,96785, AND M96786)
Dear Mr. Zeringue:
Generic Letter 96-06, " Assurance of Equipment Operability and Containment integrity During Design-Basis Accident Conditions," dated September 30,1996, included a request for licensees to evaluate cooling water systems that serve containment air coolers to assure that they are not vulnerable to water hammer and two-phase flow conditions. Tennessee Valley Authority j
provided its assessment for Browns Ferry, Unit Nos.1,2 and 3, in letters dated 1
January 28, and October 23,1997. For the staff to complete its review of TVA's resolution of the water hammer and two-phase flow issues, additional information, as discussed in the attachment, is required.
Please provide your response no later than June 30,1998.
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Sincerely,
)
(Original Signed By) 1 I
Albert W. De Agazio, Sr. Project Manager i
Project Directorate 11-3 Division of Reactor Projects - 1/11 Office of Nuclear Reactor Regulation i
l Docket Nos. 50-259,50-260, and 50-296 l
Serial No. BFN-98-009 1
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Enclosure:
Request for Additional gi h h k t} g g g Information cc w/ encl: See next page.
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DISTRIBUTION:
l BemWFPU6 J. Zwolinski(A)
A. De Agazio L. Plisco, Region ll j
PUBLIC F.. Hebdon OGC J. Tatum q Dg BFN R/F B. Clayton ACRS M. Hart 7
To receive a copy of this document, indicate in the box: 'C" = Copy without attachment / enclosure "E" = Copy with d
attachment / enclosure "bl" = No copy 0FFICE PM:PDil 3 M l E LA:PDII 3 l
DP911-I) A l
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NAME ADeAgatio\\6 BClayton 74W FMebdonljV/
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DATE 05////98 05/ 14 /98 05/ fl/ /98 05/
98 05/ /98 l
Official Record Copy DO'CUMENT NAME: G:\\BFN'.96-06RAI.WPD 9805260299 990514 9
PDR ADOCK 05000259 a
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Mr. O. J. Zeringue BROWNS FERRY NUCLEAR PLANT Tennessee Valley Authority cc:
i Mr. J. A. Scalice, Senior Vice President Mr. Mark J. Burrynski, Managar Nuclear Operations Nuclear Licensing Tennessee Valley Authority Tennessee Valley Authority 6A Lookout Place 4J Blue Ridge 1101 Market Street 1101 Market Street Chattanooga, TN 37402-2801 Chattanooga, TN 37402-2801-Mr. Jack A. Bailey, Vice President Mr. Timothy E. Abney, Manager Engineering & Technical Services Licensing and Industry Affairs i
Tennessee Valley Authority Browns Ferry Nuclear Plant 6A Lookout Place Tennessee Valley Authority 1101 Market Street P.O. Box 2000 Chattanooga, TN 37402-2801 Decatur, AL 37402-2801 Mr. C. M. Crane, Site Vice President Regional Administrator, Region ll Browns Ferry Nuclear Plant U.S. Nuclew Regulatory Commission Tennessee Valley Authority 61 Forsyth Street, SW., Suite 23T85 P.O. Box 2000 Atlanta, GA 30303-3415 Decatur, AL 35609 Mr. Leonard D. Wert General Counsel Senior Resident inspector Tennessee Vallsy Authority U.S. Nuclear Regulatory Commission ET 10H Browns Feny Nuclear Plant 400 West Summit Hill Drive 10833 Shaw Road Knoxville,TN 37902 Athens, AL 35611 Mr. Raul R. Baron, General Manager State Health Officer Nuclear Ast,urance Alabama Dept. of Public Health Te,inessee Valley Authority 434 Monroe Street 4J Blue Ridge Montgomery, AL 35130-1701 1101 Market Street Chattanooga, TN 37402-2801 Chairman Limestone County Commission Mr. Karl W. Singer, Plant Manager 310 West Washington Street Browns Ferry Nuclear Plant Athens, AL 35611 Tennessee Valley Authority P.O. Box 2000 Decatur, AL 35609 i
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REQUEST FOR ADDITIONAL INFORMATION FOR RESOLUTION OF l
GENERIC LETTER 96-06 ISSUES AT BROWNS FERRY UNIT NOS.1,2, AND 3 (TAC NOS. M96784, M96785, AND M96786) i 1.
If a methodology other than that discussed in NUREG/CR-5220, " Diagnosis of Condensation-Induced Water hammer," was used in evaluating the effects of water hammer, describe this altemate methodology in detail. Explain why this methodology is applicable and gives conservative results for the Browns Ferry units. Typically, this is accomplished through -igorous plant-specific modeling, testing, and analysis.
2.
For both the water hammer and two-phase flow analyses, provide the following information:
j a.
Identify any computer codes that were used in the water hammer and two-phase i
flow analyses and describe the methods used to bench mark the codes for the specific loading conditions involved (see Standard Review Plan Section 3.9.1).
b.
Describe and justify all assumptions and input parameters (including those used in any computer codes) such as amplifications due to fluid-structure interaction, cushioning, speed of sound, force reductions, and mesh sizes. Explain why the values selected give conservative results. Provide justification for omitting any effects that may be relevant to the analysis, e.g., fluid structure interaction, flow j
induced vibration, erosion.
c.
Provide a detailed description of the " worst case" scenarios for water hammer and two-phase flow (should be bounding for all three units), taking into consideration the complete range of event possibilities, system configurations, and parameters. For example, all water hammer types and water slug scenarios should be considered, j
as well as temperatures, pressures, flow rates, load combinations, and potential 1
component failures. Additional examples include:
l the effects of void fraction on flow balance and heat transfer; I
+ the consequences of steam formation, trar: sport, and accumulation; cavitation, resonance, and fatigue effects; and erosion considerations, a
i Licensees may find NUREG/CR-6031, " Cavitation Guide for Control Valves," helpful in addressing some aspects of the two-phase flow analyses.
l-d.
Confirm that the analyses included a complete failure modes and effects analysis (FMEA) for all components (including electrical and pneumatic failures) that could impact performance of the cooling water system and confirm that the FMEA is documented and available for review, or explain why a complete and fully documented FMEA was not performed.
1 ENCLOSURE i
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\\ ' e.
Explain and justify all uses of " engineering judgment."
3.
Determine the uncertainty in the water hammer and two-phase flow analyses. Explain how the uncertainty was determined, and how it was accounted for in the analyses to assure conservative results for the Browns Feny units.
i 4.
Confirm that the water hammer and two-phase flow loading conditions do not exceed any design specifications or recommended service conditions for the piping system and components, including those stated by equipment vendors. Confirm that the system will remain intact during all event scenarios.
5.
Provide a simplified diagram of the system, showing major components, active components, relative elevations, lengths of piping runs, and the location of any orifices and flow restrictions.
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