ML18030A274
| ML18030A274 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 04/20/1981 |
| From: | Curtis N PENNSYLVANIA POWER & LIGHT CO. |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| IEB-80-13, PLA-712, NUDOCS 8105060572 | |
| Download: ML18030A274 (3) | |
Text
TWO NORTH NINTH STREET, ALLENTOWN, PA. 18101 PHONEr t215) 770-5151 NORMAN W. CURTIS Vice President-Engineering 8 Construction-Nuclear 770-5381 APR 30 198t Mr. Boyce H. Grier, Director Region I U.S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406 t,lAY04 198t~;
U~Sr NUCLEAR R 0ULA~
tg oghvrIISS ION SUSQUEHANNA STEAM ELECTRIC STATION IE BULLETIN 80-13 ER 100450 FILE 842-3 PLA-712 DOCKET NOS.
50-387 AND 50-388
Dear Mr. Grier:
The following information is provided in response t'a:,IE Bulletin 80-13, "Cracking in Core Spray Spargers",
as justification for exemption from the requirements of the bulletin, It is reported in IE Bulletin 80-13 that 2
BWR units, Oyster Creek and Pilgrim, have developed cracking in this piping.
Of at least 19 other plants inspected, none have observed similar cracking.
As stated in the bulletin, the mode of the cracking is apparently intergranular stress corrosion cracking (IGSCC),
caused in part by sensitization.
The bulletin requires that inspections of the core spray spargers'nd piping that connects the spargers to the inlet nozzles be performed at every refueling outage until further notice.
In view of the material requirements of NUREG 0313, particularly the carbon content of Type 304 Stainless
- steel, PP6L requested from General Electric the carbon contents of the cracked piping.
GE reported that the spargers at Oyster Creek have contents of.05% to.06%,
and Pilgrim has
.048%.
These carbon levels are typical of regular grade Type 304 stainless steel.
An examination of the certified test reports revealed that Susquehanna's core spray spargers were
~ fabricated from Type 304L, and the actual carbon content is very low at
.020%.
The connecting piping is also Type 304L.
In addition to NUREG 0313, numerous other sources acknowledge the far greater resistance to sensitization, and hence IGSCC of Type 304L 'versus regular Type 304 stainless sterol.
PENNSYLVANIA POWER 8
LIGHT COMPANY SZOSO6O
il l"
P
Mr. Boyce H. Grier Page 2
APR 2Q 1SSl PPGL believes that in view of the high radiation levels expected during the inspections and the use of Type 304L material, valid reasons exist at Susquehanna for an exemption of the inspections required by IE Bulletin 80-13.
PP&L has also learned that a crack or an indication was found on a reducing Tee fitting in the line between the core spray inlet nozzle and the core spray header at Oyster Creek.
General Electric is presently trying to determine for PPGL if this fitting is regular Type 304 or 304L. If this Oyster Creek fitting is determined to be 304L, PPSL will conduct inspections on the corresponding fittings at Susquehanna in accordance with the bulletin.
Very truly yours, N. W. Curtis Vice President-Engineering 6 Construction-Nuclear RMH/mjm cc:
Director Division of Reactor Operations Inspection Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, D.C.
20555 Mr. G.
G. Rhoads U.S. Nuclear Regulatory Commission P.O.
Box 52 Shickshinny, PA 18655 Mr. L. D. Narrow U.S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA 19406