ML032130002

Request for Additional Information Regarding the Resolution of Generic Letter 69-06 Waterhammer Issues

ML032130002
Person / Time
Site:	Saint Lucie
Issue date:	08/01/2003
From:	Moroney B NRC/NRR/DLPM/LPD2
To:	Stall J Florida Power & Light Co
Moroney B, NRR/DLPM, 415-3974
References
GL-96-006, TAC M96870, TAC M96871
Download: ML032130002 (6)

Text

August 1, 2003 Mr. J. A. Stall Senior Vice President, Nuclear and Chief Nuclear Officer Florida Power and Light Company P.O. Box 14000 Juno Beach, Florida 33408-0420

SUBJECT:

ST. LUCIE PLANT, UNITS 1 AND 2 - REQUEST FOR ADDITIONAL INFORMATION REGARDING THE RESOLUTION OF GENERIC LETTER 96-06 WATERHAMMER ISSUES (TAC NOS. M96870 AND M96871)

Dear Mr. Stall:

By letter dated July 29, 2002, as supplemented by letter dated March 13, 2003, Florida Power and Light Company submitted a response to Generic Letter 96-06, Assurance of Equipment Operability and Containment Integrity During Design-Basis Accident Conditions, concerning the resolution of waterhammer issues for the St. Lucie Plant, Units 1 and 2.

The U.S. Nuclear Regulatory Commission staff has reviewed your submittal and finds that a response to the enclosed request for additional information is needed before we can complete the review. This request was discussed with your staff on July 30, 2003, and Mr. George Madden agreed that a response would be provided by September 30, 2003.

If you have any questions, please feel free to contact me at (301) 415-3974.

Sincerely,

/RA/

Brendan T. Moroney, Project Manager, Section 2 Project Directorate II Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-335 and 50-389

Enclosure:

As stated cc w/encl: See next page

ML032130002 OFFICE PDII-2/Intern PDII-2/LA PDII-2/PM GL96-06 LEAD PM PDII-2/SC NAME BMoroney for BClayton BMoroney JTatum KJabbour for MDudek AHowe DATE 7/29/03 7/31/03 7/29/03 7/31/03 7/31/03 REQUEST FOR ADDITIONAL INFORMATION RESOLUTION OF GENERIC LETTER 96-06 WATERHAMMER ISSUES FLORIDA POWER AND LIGHT SAINT LUCIE PLANT, UNITS 1 AND 2 DOCKET NOS. 50-335 AND 50-389

1. Page 2 of the March 13, 2003, submittal (the submittal) discussed benchmark testing of Component Cooling Water (CCW) system pump coastdown and recovery following restart. Provide a comparison between these tests to a postulated loss of offsite power event at St. Lucie. Provide comparisons of steam formation within the CCW piping, number of pumps starting, maximum flow rates within the system after pump restart and waterhammer produced. Also, identify the location of the test section, discussed on page 3, relative to the CCW pumps and the containment coolers.

2. Figures on page 3 of the submittal indicate that a CCW system hydraulic (HYTRAN) code predicts higher waterhammer pressures when a reduced speed of sound is used.

It is the U.S. Nuclear Regulatory Commission (NRC) staffs understanding that when a reduced speed of sound is used in waterhammer calculations, lower waterhammer pressures should result. Explain this discrepancy.

3. The submittal states that the HYTRAN code was used to predict peak pressure produced in the waterhammer analysis. The NRC staff has not previously reviewed the HYTRAN code for waterhammer analysis within CCW piping. Provide either the HYTRAN code for staff review, or provide an analysis of the most severe waterhammer postulated within the CCW piping using the Electric Power Research Institute (EPRI) methodology that the staff has approved. If you choose to apply the EPRI methodology rather than submitting the HYTRAN code for staff review, provide the following information:

a. The maximum CCW velocity following pump restart.

b. Mass of gas in the void. Provide justification that the minimum noncondensible mass for use of the EPRI methodology will be present.

c. Amount of cushioning credited. Reference the nomograph used to determine cushioning.

d. Assumptions regarding pressure pulse shape.

e. Assumptions regarding pressure pulse duration.

Enclosure

f. Transmission coefficients used to track the pressure wave through the CCW piping.

g. Pressure pulse clipping.

4. The submittal states, on page 6, that calculated results from a water heatup transient are used as input into HYTRAN. Describe the assumptions and equations used in this calculation and justify whether the methodology is conservative.

5. The submittal states, on page 7, that the peak pressure generated in the analysis is 270 psig, the piping design pressure is 150 psig, and that the Containment Fan Cooler cooling coils have a design pressure of 225 psig. Provide justification that these components will not fail under the calculated waterhammer load.

6. Provide the maximum loads calculated for the CCW piping, supports, orifices, bends, and penetrations for the worst case column closure waterhammer. Also, provide the ratios of the maximum loads within the service water system to the allowable loads.

7. Page 11 of the submittal states that the piping, pipe support, and cooler structural analysis for the design basis case was ongoing. Provide the results of the structural analysis and include a summary of the licensing basis load combinations along with the results of the stress analysis.

8. Page 11 of the submittal states that the loads and stresses are "not sensitive to void size." Explain.

9. Page 13 of the submittal establishes commitments for completing modifications that are necessary for resolving the waterhammer issue. Provide a status update for these items.

Mr. J. A. Stall ST. LUCIE PLANT Florida Power and Light Company cc:

Senior Resident Inspector Mr. R. E. Rose St. Lucie Plant Plant General Manager U.S. Nuclear Regulatory Commission St. Lucie Nuclear Plant P.O. Box 6090 6351 South Ocean Drive Jensen Beach, Florida 34957 Jensen Beach, Florida 34957 Craig Fugate, Director Mr. Terry Patterson Division of Emergency Preparedness Licensing Manager Department of Community Affairs St. Lucie Nuclear Plant 2740 Centerview Drive 6351 South Ocean Drive Tallahassee, Florida 32399-2100 Jensen Beach, Florida 34957 M. S. Ross, Attorney Vice President, Nuclear Operations Support Florida Power & Light Company Florida Power & Light Company P.O. Box 14000 P.O. Box 14000 Juno Beach, FL 33408-0420 Juno Beach, FL 33408-0420 Mr. Douglas Anderson Mr. Rajiv S. Kundalkar County Administrator Vice President - Nuclear Engineering St. Lucie County Florida Power & Light Company 2300 Virginia Avenue P.O. Box 14000 Fort Pierce, Florida 34982 Juno Beach, FL 33408-0420 Mr. William A. Passetti, Chief Mr. J. Kammel Department of Health Radiological Emergency Bureau of Radiation Control Planning Administrator 2020 Capital Circle, SE, Bin #C21 Department of Public Safety Tallahassee, Florida 32399-1741 6000 SE. Tower Drive Stuart, Florida 34997 Mr. William Jefferson, Jr Site Vice President St. Lucie Nuclear Plant 6351 South Ocean Drive Jensen Beach, Florida 34957