ML19337A661
| ML19337A661 | |
| Person / Time | |
|---|---|
| Site: | Haddam Neck, Millstone File:Connecticut Yankee Atomic Power Co icon.png |
| Issue date: | 09/30/1980 |
| From: | CONNECTICUT YANKEE ATOMIC POWER CO. |
| To: | |
| Shared Package | |
| ML19337A626 | List: |
| References | |
| TASK-2.E.1.1, TASK-2.E.1.2, TASK-TM TAC-11733, NUDOCS 8009290384 | |
| Download: ML19337A661 (1) | |
Text
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May 12, 1979 REACTOR COOLANT SYSTEM O
BASES 3/4.4.5 STEAM GEN'.RAIGM, The Surveillance Requirements for inspection of the steam generator tubes ensure that the structural integrity of this portion of the RCS The program for inservire inspection of steam will be maintained.
generator tubes is based on a modification of Regulatory Guide l40 Revision 1.
in order to maintain surveillance of the conditions of the tubes in the event that there is evidence of mechanical damage or progressive degradation due to design, manufacturing errors, or inservice conditions Inservice inspection of steam generator tubing that lead to corrosion.
also orovides a means of characterizing the nature and cause of any tube degradation so that corrective measures can be taken.
The plant is expected to be operated in a manner such that the secondary coolant will be maintained within those chemistry limits found If the to result in negligible corrosion of the steam generator tubes.
secondary coolant chenistry is not maintained within these limits, localized corrosion may likely result in stress corrosion cracking.
I The extent of cracking during plant operation would be limited by the limitation of steam generator tube leakage between the primary coolant system and the secondary coolant system (primary-to-secondary leakage = 0.5 GPM, per steam generator). Cracks having a primary-to-secondary leakage less than this limit during operation will have an adequate margin of safety to withstand the loads imposed during norma operation and by postulated accidents.that primary-to-secondary leakag Leakage be detected by radiation inonitors of steam generator bich:..
in excess of this limit will require plant shutdown and an unscheduled l49 inspection, during which the leaking tubes will be located and plugged.
Wastage-type defects are unlikely with proper chemistry treatment However, even if a defect should develop in of the secondary coolant.
service, it will be found during scheduled inservice steam generator Plugging will be required for all tubes with imperfec-tube examinations.
tions exceeding the plugging limit of 40% of the tube nominal wall Steam generator tube inspections of operating plants have thickness.
demonstrated the capability to reliably detect degradation that has penetrated 20% of the original tube well thickness.
ltn Whenever the results of any steam generator tubing inservice inspection fall into Category C-3, these results will be promptly reported to the Comission pursuant to Specificatirn 6.E.1 prior to resumption of Such cases will be considered by the Comnission on a plant operation.
case-by-case basis and may result in a requirement for analysis, laboratory examinations, tests, additional eddy-current inspection, and revision of the Technical Specifications, if necessary.
MILLSTONE - UNIT 2 8 3/4 4-2a 8009200371