ML20153D498
| ML20153D498 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 05/04/1988 |
| From: | Gridley R TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| NUDOCS 8805090171 | |
| Download: ML20153D498 (3) | |
Text
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.i TENNESSEE VALLEY AUTHORITY CH ATTANOOG A. TENNESSEE 37401 SN 1575 Lookout Place MAY 0 41988 U.S. Nuclear Legulatory Commission ATTN: Document Control Desk Hashington, D.C.
20555 Gentlemen:
In the Matter of
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Docket Nos. 50-327 Tennessee Valley Authority
)
50-328
.cQUOYAH NUCLEAR PLANT (SQN) UNITS 1 AND 2 - CLARIFICATION OF SQN'S MICR0 BIOLOGICALLY INDUCE 0 CORROSION (MIC) PROGRAM
References:
1.
TVA letter to NRC dated January 20, 1988, "Sequoyah Nuclear Plant (SQN) Units 1 and 2 - Microbiologically Induced Corrosion (MIC) Program" 2.
TVA letter to NRC dated April 4, 1988, "Sequoyah Nuclear Plant (SQN) Units 1 and 2 - Request for Relief from the American Society of Mechanical Engineers (ASME)Section XI Code as it Relates to SQN's Microbiologically Induced Corrosion (MIC) Program" 3.
NRC letter to TVA dated March 31, 1988, "Safety Evaluation of Microbiologically Induced Corrosion (MIC)
Program" TVA is providing a clarification to the leak repair schedule that is I
contained in section IV to enclosure 1 of TVA's January 20, 1988 letter l
(reference 1) and the alternate examination section of the enclosure to TVA's April 4, 1988 letter (reference 2).
These sections are being revised to clarify SQN's prestart and postrestart repair requirements.
This clarification Addresses the timeframe that TVA intended for repair wrk under SQN's MIC Program.
These timeframes remain consistent with i
the timeframes contained in the NRC Safety Evaluation Report (reference 3)
The enclosed information supersedes section IV of I'
i'eference 1 and the alternate examination section of reference 2.
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PDR ADOCK'05000327 An Equal opportunity Employer l
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, U.S. Nuclear Regulatory Commission MM04 E If you have any questions concerning this issue, please telephone D. V. Goodin at (615) 870-7734.
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Very truly yours, TENNESSEE VALLEY AUTHORITY l
R. Gridley, Director Nuclear Licensing and Regulatory Affairs Enclosure cc (Enclosure):
Mr. K. P. Barr, Acting Assistaat Director for Inspection Programs TVA Projects Division U.S. Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 Mr. G. G. Zech, Assistant Director for Projects TVA Projects Olvision U.S. Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852 Sequoyah Resident Inspector Sequoyah Nuclear Plant 2600 Igou Ferry Road Soddy Daisy, Tennessee 37379
ENCLOSURE The following supersedes section IV of TVA's January 20, 1988 letter and the Alternate Examination section of the enclosure to TVA's April 4, 1988 letter.
Preventative Maintenance (PM) 2220, 2221, 2222, and 2223 contain the following provisions and Technical Instruction (TI)-109 will be revised to state that, when a leak is discovered, the following actions will be taken:
Before initial entrv into mode 4 (following SQN's extended outage), a work request will be written to repair the damaged area; and that repair work will be a restart requirement.
Following initial entry into mode 4 (following SQN's extended outage),
TI-109, "Non-Destructive Testing of Stainless Steel Butt-Welds to Assess Damage Resulting From Microbiological 1y Induced Corrosion (MIC)," will be used to evaluate the corrosion damage. This instruction specifies that RT will be completed within seven days after leak discovery. The RT data will be compared against a preestablished screening criteria.
If a weld is found with MIC damage that exceeds the screening criteria, that weld will receive further detailed seismic analysis within an additional seven days.
If the detailed seismic analysis determines a weld to be structurally inadequate, appropriate ERCH Technical Specification (TS) actions will be taken.
SQN experience indicates tnat all welds will be within the screening criteria; therefore, TS actions should not be required.
If the weld is considered to be structurally sound, if the leakage from the weld is insignificant (i.e., characterized as a weeper or does not pose a personnel hazard), and if there is no potential for leaking on safe shutdown equipment, then the leak will be scheduled for repair at an outage of sufficient duration to accomplish the repair but no later than the next refueling outage.
The weld will be entered into a monitoring program under PM 2241 and 2242 to monitor any type of MIC growth.
This process will be implemented in the revision to TI-109.
The plant management may, at their discretion, elect to put the system into an outage and epair the leaking joint rather than perform radiography.
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