ML20217B040
| ML20217B040 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 09/12/1997 |
| From: | Alexion T NRC (Affiliation Not Assigned) |
| To: | Cottle W HOUSTON LIGHTING & POWER CO. |
| References | |
| GL-96-06, GL-96-6, TAC-M96868, TAC-M96869, NUDOCS 9709230190 | |
| Download: ML20217B040 (4) | |
Text
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September 12, 1997 Mr. William T. Cottle Executive Vice-President &
General Manager, Nuclear Houston Lighting & Power Company South Texas Project Electric Generating Station P. O. Box 289 l
Wadsworth, TX 77483 l
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION (RAI) REGARDING GENERIC LETTER (GL) 96-06, " ASSURANCE OF EQUIPMENT OPERABILITY AND CONTAINMENT INTEGRITY DURING DESIGN-BASIS ACCIDENT CONDITIONS," SOUTH TEXAS PROJECT, UNITS 1 AND 2 (STP) (TAC NOS. M96868 AND M96869)
Dear Mr. Cottle:
l l
The Nuclear Regulatory Commission (NRC) staff is reviewing Houston Lighting &
1 Power Company's (HL&P's) January 28, 1997, response to GL 96-06. HL&P's response addresses the issues of water hammer, two-)hase flow and thermally-induced pressurization of piping runs penetrating tie containment for STP.
This letter concerns the issue of thermally-induced pressurization of piping runs penetrating the containment, in its response, HL&P identified that ten pipe lines penetrating the containment in each unit are susceptible to thermally-induced pressurization.
HL&P indicated that nine of these linos were found acceptable due to the inherent design features of the containment isolation valves.
HL&P further indicated that thermal insulation was added to the remaining line.
In order to complete the thermally-induced pressurization portion of the I
review, the staff needs the additional information identified in the enclosure regarding HL&P's evaluation of these pipe lines.
Please provide your response within 60 days from the date of this letter.
Sincerely' SIGNED BY:
ORIGINAL Thomas W. Alexion, Project Manager bbkohboh!98 Project Directorate IV-1 D
P pm Division of Reactor Projects Ill/IV Office of Nuclear Reactor Regulation Docket Nos. 50-498 and 50-499
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September 12, 1997 Mr. William T. Cottle Executive Vice-President &
General Manager, Nuclear Houston Lighting & Power Company South Texas Project Electric Generning Station P. O. Box 289 i
Wadsworth, TX 77483
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION (RAI) REGARDING GENERIC LETTER (GL) 96-06, " ASSURANCE OF EQUIPMENT OPERABILITY AND CONTAINMENT i
INTEGRITY DURING DESIGN-BASIS ACCIDENT CONDITIONS," SOUTH TEXAS PROJECT, UNITS 1 AND 2 (STP) (TAC NOS. M96868 AND M96869)
Dear Mr. Cottle:
The Nuclear Regulatory Commission (NRC) staff is reviewing Houston Lighting &
Fower Company's (HL&P's) January 28, 1997, response to GL 96-06.
HL&P's response addresses the issues of water hammer, two-)hase flow and thermally-induced pressurization of piping runs penetrating tie containment for STP.
This letter concerns the issue of thermally-induced pressurization of piping runs penetrating the containment.
In its response. HL&P identified that ten pipe lines penetrating the containment in each unit are susceptible to thermally-induced pressurization.
HL&P indicated that nine of these lines were found acceptable due to the inherent design features of the containment isolation valves.
HL&P further indicated that thermal insulation was added to the remaining line, in order to complete the thermally-induced pressurization portion of the review, the staff needs the additional information identified in the enclosure regarding HL&P's evaluation of these pipe lines.
Please provide your response within 60 days from the date of this letter.
Sincerely, N
M
'i Thomas W. Alexion, Project Manager Project Directorate IV-1 Division of Reactor Projects III/IV Docket Hos. 50-498 and 50-499
Enclosure:
RAI cc w/ enc 1:
See next page
Mr. William T. Cottle d
Houston Lighting & Power Company South Texas, Units 1 & 2 CC:
Mr. David P. Loveless Jack R. Newman, Esq.
Senior Resident inspector Morgan, Lewis & Bockius U.S. Nuclear Regulatory Comission 1800 M Street, C.W.
P. O. Box 910 Washington, DC 20036-5869 Bay City, TX 77414 Mr. Lawrence E. Martin Mr. J. C. Lanier/M. B. Lee General Manager, Nuclear Assurance Licensing City of Austin Houston Lighting and Power Company Electric Utility Department P. O. Box 289 721 Barton Springs Road Wadsworth, TX 77483 Austin, TX 78704 Rufus S. Scott Mr. M. T. Hardt Associate General Counsel Mr. W. C. Gunst Houston Lighting and Power Company City Public Service Board P.. O. Box 61867 P. O. Box 1771 Hobston, TX 77208 San Antonio, TX 78296 Joseph R. Egan, Esq.
Mr. G. E. Vaughn/C. A. Johnson Egan & Associates, P.C.
Central Power and Light Company 2300 N Street, N.W.
P. O. Box 289 Washington, DC 20037 Mail Code:
N5012 Wadsworth, TX 74483 Office of the Governor ATTN: Andy Barrett, Director INPO Environmental Policy Records Center P. O. Box 12428 700 Galleria Parkway Austin, TX 78711 Atlanta, GA 30339-3064 Arthur C. Tate, Director Regional Administrator, Region IV Division of Compliance & Inspection U.S. Nuclear Regulatory Commission Bureau of Radiation Control 611 Ryan Plaza Drive, Suite 400 Texas Department of Health Arlington, TX 76011 1100 West 49th Street Austin, TX 78756 Dr. Bertram Wolfe 15453 Via vaquero Texas Public Utility Commission Monte Sereno, CA 95030 ATTN: Mr. Glenn W. Dishong 7800 Shoal Creek Blvd.
Judge, Matagorda County Suite 400N Matagorda County Courthouse Austin, TX 78757-1024 1700 Seventh Street Bay City, TX 77414 p
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RE0 VEST FOR ADDITIONAL INFORMATION (RAll GENERIC LETTER (GL) 96-01 SOUTH TEXAS PROJECT. UNITS 1 AND 2 1.
The January 28, 1997, submittal, indicated that nine piping runs susceptible to thermally-induced overpressure were determined to be acceptable based on the valve design. These piping runs contained l
either spring-loaded valves that form isolation barriers or valves that will self-relieve through leakage that form isolation barriers.
In the submittal, it was stated that these valves would relieve water to l
preclude an overpressure condition.
Provide the following information for each piping run evaluated in this manner:
Describe the applicable design criteria for the piping and the a.
valves.
Include the required load combinations.
b.
Provide a drawing of the valve.
Provide the pressure at which the valve was determined to lift off its seat or leak and describe the method used to estimate this
>ressure.
Discuss any sources of uncertainty associated with tie estimated lift off pressure.
Provide the maximum-calculated stress in the piping run based on the c.
estimated lif t off or leakage pressure.
2.
The_ January 28, 1997, submittal, indicated that the reactor coolant pump drain tank line was insulated in order to maintain piping stresses within the allowable limits.
Provide the following information for this piping run:
Provide the appitcable design criteria for the piping and the a.
valves.
Include the required load combinations, b.
Provide a drawing of the )iping run between the isolation valves, include the lengths and t11cknesses of the piping segments and the type and thickness of the insulation, Provide the 'naximum-calculated tem)erature and pressure for the pipe c.
run. Describe, in detail, the met 1od used to calculate these pressure and temperature values.
This should include a discussion on the heat transfer model used in the analysis and the basis for the heat transfer coefficients used in the analysis.
ENCLOSURE