ML20081J318
| ML20081J318 | |
| Person / Time | |
|---|---|
| Site: | Farley  |
| Issue date: | 03/20/1995 |
| From: | Dennis Morey SOUTHERN NUCLEAR OPERATING CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9503270216 | |
| Download: ML20081J318 (2) | |
Text
m Southern Nuchir Opar: tang Company Post Offica Box 1295 Birmingham, A!1bama 35201 Telephone (205) 868-5131 L
o m forey Southern Nudear Operating Company vce Presidant Farley Project the Southem electHC System March 20, 1995 Docket No.: 50-364 U.S. Nuclear Regulatory Commission ATIN.: Document Control Desk Washington, D.C. 20555 Joseph M. Farley Nuclear Plant Technical Specification Changes Associated With Steam Generator Tube Suonort Plate Voltage-Based Repair Criteria Gentlemen:
By letter dated December 7,1994, Southern Nuclear (SNC) requested technical specification changes associated with permanent steam generator tube support plate voltage-based repair criteria for Farley Units 1 and 2. By letter dated February 14,1995, SNC revised its request for Farley Unit 2 to a single operating cycle steam generator repair criteria. Following discussions with the NRC Staff on March 10,13, and 15,1995, the following clarifications are prosided to resolve Staff questions.
1.
SNC will inspect all intersections where copper signals interfere with the detection of flaws with a motorized rotating pancake coil (RPC) probe. (draft Generic Letter 3.b.3) 2.
SNC will inspect all intersections with large mixed residuals with an RPC probe. (draft Generic Letter 3.b.5)
- 3. SNC will inspect all bobbin flaw indications with voltages greater than 1.5 volts with an RPC probe. (draft Generic Letter 3.b.1) 4.
Probe wear inspections /re-inspections will be governed by the same practices used during the last Farley Unit I steam generator inspections. Rese practices were forwarded to the NRC by letter dated February 23,1994 which states in part:
If any of the last probe wear standard signal amplitudes prior to probe replacemmt exceed the 115% limit, say by a value of X%, then any indications measured since the lau acceptable probe wear measurement that are within X% of the plugging limit must be re-inspected with the new probe. For example, if any of the last probe wear signal amplitudes prior to probe replacement were 17% above or below the initial amplitude, then indications that are within 2% (17%-15%) of the plugging limit must be re-inspected with the new probe. Altematively, the voltage criterion may be lowered to compensate for the excess variatian; for the case above, amplitudes 20.98 times the voltage criterion could be subject to repair. (draft Generic Letter 3.c.4) 5.
SNC will brief eddy current analysts of the possibility of PWSCC occurring at tube support plate intersections. De discovery of PWSCC at tube support plate intersections will be reported to the NRC Staff prior to startup.
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- 6. No distribution cutoff will be applied to the voltage measurement variability distribution. (draft Generic Letter 2.b.2(1))
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- 7. Calculations performed in support of the voltage-based repair criteria will follow the methodology described in WCAP-14277, SLB Leak Rate and Tube Burst Probability Analysis Methods for ODSCC at TSP Intersections, January,1995. (draft Generic Ixtter 2.a and 2.b) 8.
SNC will attempt to pull a single tube with three intersections from a Farley steam generator. The tube pull will be successful if at least two intersections are successfully pulled.
1 The following information concerning Unit 2 cyde length is also being pro 5ided at the request of the staff:
Cycle 9 462 EFPD (15.4 EFPM) t Cycle 10 439 EFPD (14.6 EFPM)
Cycle 11 predicted 479 EFPD (16.0 EFPM) l If there are any questions, please advise.
Respectfully submitted, SOUTHERN NUCLEAR OPERATING COMPANY
[ h 7/W Dave Morey RTMcitlPC3A. DOC l
SWORN TO AND SUBSCRIBED BEFORE ME cc:
Mr. S. D. Ebneter THIS OO DAY OF 1995 f(
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ss Dr. D. E. Williamson Notary Phb(gl Mr. T. A. Reed My Commission Expires: // /d/
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