ML20247L662
| ML20247L662 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 05/15/1998 |
| From: | Alexion T NRC (Affiliation Not Assigned) |
| To: | Cottle W HOUSTON LIGHTING & POWER CO. |
| References | |
| TAC-MA0350, TAC-MA0351, TAC-MA350, TAC-MA351, NUDOCS 9805260039 | |
| Download: ML20247L662 (4) | |
Text
- - _ _ _ _ _ - - _ _ _ _ _ _ _ _ _ - _ _ - _ _ _ _
Mr. William T. Cottle May 15 1998 0
President and Chief Executive Officer STP Nuclear Operating Company South Texas Project Electric Generating Station P. O. Box 289 Wadsworth, TX 77483
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION ON ALTERNATE OPERATION WITH REDUCED MEASURED REACTOR COOLANT SYSTEM FLOW, SOUTH TEXAS PROJECT, UNITS 1 AND 2 (STP) (TAC NOS. MA0350 AND MA0351)
Dear Mr. Cottle:
The Nuclear Regulatory Commission (NRC) staff is reviewing STP Nuclear Operating Company's (STPNOC's) December 31,1997, application for a license amendment to revise Technical Specification 2.1 (Safety Limits),2.2 (Limiting Safety System Settings), and 3/4.2.5 (Departure from Nucleate Boiling Parameters) by includin0 attemate operating criteria to allow continued plant operation with a reduced measured reactor coolant system flow rate, if necessary.
Based on its review, the staff has determined that additional information is needed, as discussed in the enclosure.
Sincerely, ORIGINAL SIGNED BY:
Thomas W. Alexion, Project Manager Project Directorate IV-1 Division of Reactor Projects ill/IV Office of Nuclear Reactor Regulation Docket Nos. 50-498 and 50-499
Enclosure:
Request for Additional Information cc w/ encl: See next page D
j p p.
p,g ca Gn D & S z g
/
DISTRIBUTION:
Docket File a PUBLIC PD4-1 r/f TGwynn, RIV p.
EAdensam (EGA1)
JHannon CHawes EWeiss -
)
TAlexion OGC ACRS REmch Document Name: STPA0350.RAI f 4 OFC PM/PDJW LA/PD4-1 SL/SRXBy SL/PERB P P IV-1 NAME TAlexid CHawYe ewe RE M babnon DATE I/h /98 7/f3 /98 fi/I/98 5/
7/k9A (kES)NO NO )
ES YES/NO YES/NO YES/NO YE COPY U
OFFICIAL RECORD COPY l
l 9805260039 980515 PDR ADOCK 05000498 P
PDR L----____---_.--__
- 209 g
t UNITED STATES s
j NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. - aaa1 k*****
May 15,1998 Mr. William T. Cottle President and Chief Executive Officer STP Nuclear Operating Company South Texas Project Electric Generating Station P. O. Box 289 Wadsworth,TX 77483
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION ON ALTERNATE OPERATION WITH REDUCED MEASURED REACTOR COOLANT SYSTEM FLOW, SOUTH TEXAS PROJECT, UNITS 1 AND 2 (STP)(TAC NOS. MA0350 AND MA0351)
Dear Mr. Cottle:
The Nuclear Regulatory Commission (NRC) staff is reviewing STP Nuclear Operating Company's (STPNOC's) December 31,1997, application for a license amendment to revise Technical Specification 2.1 (Safety Limits),2.2 (Limiting Safety System Settings), and 3/4.2.5 (Departure from Nucleate Boiling Parameters) by including attemate operating criteria to allow continued plant operation with a reduced measured reactor coolant system flow rate, if necessary.
Based on its review, the staff has determined that additionalinformation is needed, as discussed in the enclosure.
Sincerely, g
i Thomas W. Alexion, Project Manager Project Directorate IV-1 Division of Reactor Projects lil/IV Office of Nuclear Reactor Regulation Docket Nos. 50-498 and 50-499
Enclosure:
Request for Additional Information cc w/ encl: See next page i
l
Mr. William T. Cottle STP Nudear Operating 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 Commission 1800 M Street, N.W.
P. O. Box 910 Washington, DC 20036-5869 Bay City, TX 77414 Mr. Lawrence E. Martin A. Ramirez/C. M. Canady Vice President, Nuc. Assurance & Licensing
_ City of Austin STP Nuclear Operating Company Electric Utility Department P. O. Box 289 721 Barton Springs Road Wadsworth, TX.77483 Austin,TX 78704 Office of the Govemor Mr. M. T. Hardt ATTN: John Howard, Director L
Mr. W. C. Gunst Environmental and Natural 1
City Public Service Board Resources Policy P. O. Box 1771 P. O. Box 12428 San Antonio, TX 78296 Austin, TX 78711 i
Mr. G. E. Vaughn/C. A. Johnson Jon C. Wood Central Power and Light Company Matthews & Branscomb P. O. Box 289 One Alamo Center Mail Code: N5012 106 S. St. Mary's Street, Suite 700 Wadsworth, TX 74483 San Antonio, TX 78205-3692 INPO Arthur C. Tate, Director Records Center Division of Compliance & Inspection j
700 Galleria Parkway Bureau of Radiation Control i
Atlanta, GA 30339-3064 Texas Department of Health i
1100 West 49th Street I
Regional Administrator, Region IV Austin, TX 78756 U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 Jim Calloway Arlington,TX 76011 Public Utility Commission of Texas Electric Industry Analysis D. G. Tees /R. L. Balcom P. O. Box 13326 Houston Lighting & Power Co.
Austin, TX 78711-3326 P. O. Box 1700 Houston,TX 77251 Judge, Matagorda County Matagorda County Courthouse 1700 Seventh Street Bay City, TX 77414 I
i I
u
O i
REQUEST FOR ADDITIONAL INFORMATION 1.
Discuss the e#ects of the reduced reactor coolant system (RCS) flow on the design transients that were used in the fatigue analysis evaluation of affected coraponents with respect to the number of occurrences for each transient.
2.
Provide a summary of the evaluations (including analytical methodology, assumptions, and maximum stress and fatigue usage factors) for the structural integrity of the reactor vessel and intomals, RCS piping, control rod drive mechanisms (CRDMs) and housing, pressurizer, surge line (stratification), pressurizer spray nozzles, steam generators (SGs),
reactor coolant pumps (RCPs), and pressurizer power-operated valves and safety valves.
The requested summary should discuss the evaluations based on the design parameters (i.e., RCS pressure, hot leg temperature (T-hot), cold leg temperature (T-cold), diWorential pressure, differential temperature, and steam pressure and temperature) for the current operation, the proposed operation, and the design basis analysis.
3.
The decrease in steam pressure results in the increase in the primary-to-secondary pressure difference and the break flow inside the SGs. Discuss the evaluation of the effect of decreased steam pressure on the design basis analysis of the SGs with respect to the stresses and fatigue usage.
4.
On page 7 of 12 of Attachment 2, there is discussion o. steam generator tube rupture associated with the proposed 3% reduction in thermal design flow. Please provide information regarding any change in the mass flow of the steam / water release by indicating if there is any increase or decrease, and if so, how much. Please provide supporting background information.
5.
On page 5 of 12 of Attachment 2, there is discussion on the radiological consequences of a design-basis loss-of-coolant accident. Please verify that the 3% reduction in thermal design flow does not change any of the input parameters in the radiological consequences evaluation.
l l
i l
ENCLOSURE L
-