ML052980153
| ML052980153 | |
| Person / Time | |
|---|---|
| Site: | Watts Bar  |
| Issue date: | 10/20/2005 |
| From: | Pace P Tennessee Valley Authority |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| IR-05-013 | |
| Download: ML052980153 (6) | |
Text
Tennessee Valley Authority, Post Office Box 2000, Spring City, Tennessee 37381-2000 OCT 2 0 2005 10 CFR 50.4 U. S. Nuclear Regulatory Commission ATTN:
Document Control Desk Washington, D.C. 20555-0001 Gentlemen:
In the Matter of
)
Docket No. 50-390 Tennessee Valley authority
)
WATTS BAR NUCLEAR PLANT (WBN) UNIT 1 -
NRC INSPECTION REPORT NO. 05000390/2005013; PRELIMINARY GREATER THAN GREEN FINDING; WATTS BAR NUCLEAR POWER PLANT -
SUBMITTAL OF REGULATORY CONFERENCE MEETING PACKAGE -
SUPPLEMENT In a letter dated October 18,
- 2005, TVA provided the subject Regulatory Conference Meeting Package.
Attached are three errata pages for the subject presentation.
If you have any questions concerning this matter, please call me at (423) 365-1824.
Sincerely, P. L. Pace Manager, Site Licensing and Industry Affairs Enclosure cc:
See Page 2 Pted on acied pow
U.S. Nuclear Regulatory Commission Page 2 OCT 2 0 2005 Enclosure cc (Enclosure)
NRC Resident Inspector Watts Bar Nuclear Plant 1260 Nuclear Plant Road Spring City, Tennessee 37381 Mr. D. V. Pickett, Project Manager U.S. Nuclear Regulatory Commission MS 08G9a One White Flint North 11555 Rockville Pike Rockville, Maryland 20852-2738 U.S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth St., SW, Suite 23T85 Atlanta, Georgia 30303
Enclosure
Difference No. 3 Available RHR Suction Relief Valve
- NRC RHR relief valve failure probability 1E-3 No specific data in NRC SPAR model for small relief valves NRC selected "similar valve" - pressurizer code safety Pressurizer code safety designed to lift at 2485 psig and 680'F.
Pressurizer code safety challenged by adverse conditions
- TVA RHR relief valve failure probability 2.42 E-5 TVA used PLG-0500, "Database for Probabilistic Risk Assessment for Light Water Nuclear Power Plants" in IPE NRC staff evaluation of IPE documented in SER dated October 5, 1994 SER specifically recognizes PLG-0500, "Database for Probabilistic Risk Assessment for Light Water Nuclear Power Plants" PLG database reviewed by NRC - NUREG/CR5606 - concluded database was extensive and "state of the art"
Conclusion:
VVBN value is Current Licensing Basis for this component 20
"Adjusted" NRC Event Tree Loss of RCS Injection Isolate RIR RHtR RECOV RWST Steam Inventory before Open PORV Before RWST Makeup Generator Depletes Before Cooling LOI FEED ISOLATE RIIRREC RWSTMU SGEN COOL N
END-STATE-NAMES I
OK 2
O K 0.5 OK 1E-2 1E-3 3
CD-(SE16) 3E-9 1iA 6E-4 1E-2 OK
.1E3 z 4
CD-(I" 7E-9 See Next Slide for Explanation WE-4 C CDSa 40 7/6E-8 WATTS BAR LOCA TREE - COP Scenario 4 2005/07/18 Page 2 27
"Adjusted" NRC Event Tree Expanded 1E-2 Path Loss of RCS Injection Isolate 74-1 Open Block Open PORV RWST Retill Steam Inventory before or 74-2 Valve Generator Cooling LOI FEED END-STATE-NAMES 9.94E-1 A
See previous page 9.99E-1 n
OK 1E+0 6E-3r IE-3 C
CD -3.59E-9 9.99E-1 D
OK 3E-3 1E-3 E
CD -1.80E-9 (1E-2 Expanded 0.99 1$4 6E-4 sequence) 3E-4 1E-4 1E-2 G
CD - 1.80E-9 WATTS BAR LOCA TREE - COP Scenario 4 2005/07/18 Page 2 Total 7E-9 28
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