ML19276H600
| ML19276H600 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon, Crane  |
| Issue date: | 10/24/1979 |
| From: | Knight J Office of Nuclear Reactor Regulation |
| To: | Varga S Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19276H599 | List: |
| References | |
| TASK-AS, TASK-BN-79-33 BN--79-33, BN-79-33, NUDOCS 7912070030 | |
| Download: ML19276H600 (2) | |
Text
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UNITED STATES
,[ ' j NUCLEAR REGULATORY COMMISSION
, g WASHINGTO *l. D. C. 20555 9, ^
a CC' ; 4 ig79
.AuRANDUM FOR:
S. A. Varga, Acting Assistant Director for Light Water Reactors Division of Project Management FROM:
J. P Knight, Assistant Director for Engineering
SUBJECT:
LICENSING BOARD NOTIFICATION OF PIPE CRACKS IN SORATED ',-lATER SYSTEMS In response to your memorandum of August 30, 1979, on the need for board notification, we have reviewed the information on cracking in stagnant boron lines available to us and recommend that this information be provided to the pertinent boards (Attachments 1, 2 and 3).
An assessment of the significance of the matter is discussed in Attachment 1, 00R Operating Experience Memorandum No.17, October 5,1979 and Attachment 2, Menorandum D. Eisenhut to E. S. Christenbury, August 14, 1979.
We are pursuing this matter by having Dr. John Weeks, BNL, our consultant on corrosion and water chemistry, evaluate the safety significance of the instances of cracking in operating plants as it relates to plants in the licensing process.
As a matter of information, cracks in boric acid lines of this type in PURs have been discussed by the NRC Pipe Crack Study Group in their report,
" Investigation and Evaluation of Stress Corrosion Cracking in Piping of Light Water Reactor Plants," NUREG-0531, dated February 1979. The specific pages in which this is discussed are included here as Attachment 3.
The updated assessment by Dr. Weeks is being ~ requested because of extensive metallurgical examinations being done oc TMI cracked lines which may shed further light on the phenomenon since the Pipe Crack Study Group Report was issued.
1s a bjf I
J J
P. Knight, Assistant Director
/ for Engineering
' Division of Systems Safety Office of Nuclear Reactor Regulation
Enclosure:
As stated For cc's, see attached sheet 1522 134 b
7912070
~
C L'I 1379 S. A. Varga cc:
F. Schroeder D. G. Eisenhut S. S. Pawlicki H. F. Conrad B. Turovlin J. Weeks, BNL R. M. Grustafson
Contact:
H. F. Conrad X27255 1522 135