3F1286-05, Forwards SAIC-86/1098, Crystal River Unit 3 Emergency Feedwater Sys Reliability Analysis. Study Incorporates All Recent Improvements to Sys.Sys Believed Highly Reliable & Adequate in Fulfilling Role in Accident Mitigation

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Forwards SAIC-86/1098, Crystal River Unit 3 Emergency Feedwater Sys Reliability Analysis. Study Incorporates All Recent Improvements to Sys.Sys Believed Highly Reliable & Adequate in Fulfilling Role in Accident Mitigation
ML20214V326
Person / Time
Site: Crystal River Duke Energy icon.png
Issue date: 12/02/1986
From: Eric Simpson
FLORIDA POWER CORP.
To: Stolz J
Office of Nuclear Reactor Regulation
Shared Package
ML20214V330 List:
References
3F1286-05, 3F1286-5, NUDOCS 8612090635
Download: ML20214V326 (2)


Text

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Power C OGPO R ATiON December 2, 1986 3F1286-05 Mr. John F. Stolz, Director PZ Project Directorate #6 t>ivision of PWR Liaridag B Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555

Subject:

Crystal River Unit 3 Docket No. 50-302 Operating License No. DPR-72 Emergency Feedwater System Reliability Analysis

Dear Sir:

Florida Power Corporation (FPC) is pleased to submit the Crystal River Unit 3 (CR-3) Emergency Feedwater System (EFW) Reliability Analysis. The analysis was performed using methods comparable to those cited in the NRC Standard Review Plan (SRP) Section 10.4.9, Auxiliary (Emergency) Feedwater System. The study incorporates all of the recent improvements to the CR-3 EFW system. These include installation of the Emergency Feedwater Initiation and Control (EFIC) system, addition of a redundant DC powered steam admission valve to the turbine driven EFW pump, removal of the internals of the valves in the EFW pump suction and recirculation lines, and the addition of a dedicated EFW storage tank. Although the dedicated storage tank is not yet in place, it is scheduled for installation during the next refueling outage in Fall 1987.

for EFW Revision 2 ofinStandard unreliability the range Review of 10-4Planto (SRP{

10- per 10.4.9 included demand, a goalcredit allowing for alternative means of decay heat removal (e.g., feed-and-bleed or HPI cooling). The CR-3 EFW Reliability Analysis calculated an unreliability of the EFW System of 1.9 x 10-4 per demand given a loss of main feedwater.

The unreliability of the HPI System to Provide feed-and-bleed cooling is 1.2 x 10-4, as calculated in the CR-3 ProDabilistic Risk Assessment (PRA).

Together, these two " decay heat removal" systems combine for an unreliabili ty of 2.3 x 10-8 per demand, significantly below the SRP j unreliability goal . The CR-3 study has shown that the EFW system alone, CP 8612090635 861202 I1 PDR ADOCK 05000302  %

P PDR GENERAL OFFICE: 3201 Thirty-fourth Street South e P.O. Box 14042 e St. Petersburg, Florida 33733 * (813) 866-5151 A Florida Progress Company

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t f.' December 2, 1986 i 3F1286-05 wi thout consideration of any alternative decay heat removal methods, approaches the SRP goal of 1 x 10-4 per demand. A more global assessment of the importance of the EFW system, provided by the CR-3 PRA, found the contribution of EFW equipment failures to the overall core damage frequency to be minimal .

With the insights gained through the CR-3 EFW Reliability Analysis and the PRA, FPC believes that the EFW system is highly reliable and more than adequate in fulfilling its role in accident mitigation.

Sincerely, E. C. Simpson Director, Nuclear Operations Engineering and Licensing MWA/feb Attachment xc: Dr. J. Nelson Grace Regional Administrator, Region II U.S. Nuclear Regulatory Commission 101 Marietta Street N.W., Suite 2900 Atlanta, GA 30323

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