ML20205C709
| ML20205C709 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 09/18/1985 |
| From: | SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | |
| Shared Package | |
| ML20205C698 | List: |
| References | |
| NUDOCS 8509230166 | |
| Download: ML20205C709 (1) | |
Text
_ _ _ _ _ _ _. _ _ _
v.
ATTACHMENT 1 i
REACTOR COOLA T' SYSTEM BASES 3/4.4.5 STEAM GENERATORS The Surveillance Requirements for inspection of the steam generator tubes j
ensure that the structural integrity of this portion of the RCS will be main-(-
The program for inservice inspection of steam generator tubes is based tained.
on a modification of Regulatory Guide 1.83, Revision 1.
Inservice inspection of steam generator tubing is essential 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 (I
conditions that lead to corrosion.
Inservice inspection of steam generator tubing also provides 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 I
coolant will be maintained within those chemistry limits found to result in negligible corrosion of the steam generator tubes.
If the secondary coolant i
chemistry is not maintained within these limits, localized corrosion may i
likely result in stress corrosion cracking. 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 i
(primary-to-secondary leakage = 500 gallons per day 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 I
(
imposed during normal operation and by postulated accidents.
Operating plants i
have demonstrated that primary-to-secondary leakage of 500 gallons per day per steam generator can readily be detected by radiation monitors of steam generator blowdown.
Leakage in excess of this limit will require plant shutdown and an unscheduled inspection, during which the leaking tubes will be located and plugged.
1 Wastage-type defects are unlikely with proper chemistry treatment of the Ng secondary coolant. However, even if a defect should develop in service, it i
p O. M
- PP"*
will be found during scheduled inservice steam generator tube examinations.
i
- n 7L;;'.; will'be required for all tubes with imperfections exceeding 4he-g,;,;;,; it;;;it M 405 of the tube nominal wall thickness.
tube inspections of operating plants have demonstrated the capability to
(
reliably detect degradation that has penetrated 205 of the original tube wall thickness.
y i
Whenever the results of any steam generator tubing inservice inspection fall into Category C-3, these results will be promptly reported to the Commission pursuant to 10 CFR 50.72(b)2(1) prior to resumption of plant operation.
Such cases will be considered by the Commission on a case-by-case basis and may l
(
result in a requirement for analysis, laboratory eaaminations, tests, additional j
{
eddy-current inspection, and revision of the Technical Specifications, if l
necessary.
[
f M '# N $
,95 f
Supe 1ER - UNIT 1 8 3/4 4-3
?.C -t %
- - -