ML20138G057
| ML20138G057 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 06/12/1985 |
| From: | Moskowitz J PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | Ebneter S NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| NUDOCS 8510250401 | |
| Download: ML20138G057 (3) | |
Text
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s PHILADELPHIA ELECTRIC COMPANY 2301 M ARKET STREET P.O. BOX 8699 PHILADELPHI A. PA.19101 JUN 131935 (215)8414o00 tucentteimo amo ecstancw oceaeratur Mr. Stewart D. Ebneter, Director Docket No. 50-277 Division of Reactor Safety U. S. Nuclear Regulatory Cm mission Region I 631 Park Avenue King of Prussia, PA 19406
Dear Mr. Ebneter:
Your letter of May 19, 1985, forwarded Inspection Report 50-277/85-04 covering insoection of the primary system pipe replacement. activities on Peach Bottcm Unit 2.
This report identified two unresolved items for which we have obtained additional information to resolve the matters. A discussion of our resolutions of the two items was held by our Mr. F. J. Ccyle on May 30,1985 with Mr. S. D. Reynolds, Jr. of your staff.
Mr. Reynolds indicated that he was satisfied with our resolution of unresolved item 277/85-04-01 and noted that no other actions were necessary.
For unresolved item 277/85-04-02, Mr. Reynolds requested that we forward a discussion of our resolution in a correspondence to your office.
Unresolved item 277/85-04-02 is restated below along with our response.
Unresolved item 277/85-04-02 During review of vendor supplied pipe and pipe fitting radiographs it was noted that many films had transverse indications approximately 1/4" to 3/8" wide having the appearance of a solidification pattern which appeared to be in the root pass or root area. The indications were in the longitudinal seams of pipe supplied by Youngstcwn Welding and Engineering to Johnson Controls for GE NEBO. The indications were all dispositioned by Johnson Controls tas "non-relevant transverse trotecular alignment indications for YWSE Order C-1162". An example of these Indications is found on 1.5" thick, 28" 0.D., SA358 Grade 316, double welded pipe for GE drawing 112D3305G001 Tube #4.
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o The inspectcr discussed this anomaly with a metallurgical representative cf NEB 0 and with the licensce. The licensee conmitted to obtain copies of the referenced rierron Testing Laboratories
't.nllurgical report to Johnson Controls and to provide a
- ' ?urgical 9xplanation of why these linear appearing indications SCIII rejectable and are not detrimental to the service m*
.iormance of the pipo.
Region I also obtained a piece of pipe containing the radiographic Indications for an independent evaluation.
This item is considered unresolved pending further NRC testing (277/85-04-02).
Response
A copy of the Herron Terting Laboratories metallurgical report was given to Mr. S. D. Reynolds, Jr. on May 30, 1985.
Sanples of the pipe containing molecular alignment Indications representing the worst condition, were sent to Herron Testing Laboratories for examination. A sanple was sectioned across the longitudinal center-line of the wold ard enlarged to determine the location of the alignment Indicatic;ns frcm the outside surface of the weld. The photomacrographs revealed the molecular alignment to be in the double-welded root area of the weld with no indications of incaTplete fusion. A.505" all-weld tenslie specimen was machined frcm the root area and a tensile test was pulled. The results of the test revealed a yleid of 41,750 ps1 and an ultimate of 80,500 psi. These values are well above the minimum requiranents of the applicable material specifications. Furthernere, the photcmacrographs showed the weld to be sound and free of defects.
In addition to the tenslie testing, radiographs were taken of the same area of weld using different sources and film. Radiographs were taken using x-ray on AA film, ganma on M film and ganma on D film.
The radiographs using x-ray show the al!gnment Indications whereas the ganma source radlographs do not. These results show that the alignment Indications are a result of x-ray diffraction. X-rays are diffracted because their wave lengths are in close proximity of the lattice spacing of the specimen material. Ganma rays are not refracted because their wave lengths are small fractions of the lattice spacing of the specimen material.
The results of the radiograph comparisons, photcmacrographs, and the tensile test show that the presence of the diffraction patterns on the radiographs do not Indicate a weld Integrity problem or a detrinrntal metallurgical condition.
We have also reviewed the acceptance radiographs of the 28 inch cean welds which contain the diffraction patterns. We have concluded that these radiographs rncet the quality requirements of ASME Section V.
The aligrynent Indications are subtle, consisting of gradual density changes which would not mask the existence of relevant Indications. Furthernure the Indications are transverse to the direction of the weld and therefore transverse to any expected indications.
If you have any questions or require additional information, please do not hesitate to contact us.
Sincerely, d M(i> I ~ #
John Moskowlt Engineer-in-Charge Power Plant Design Section Mechanical Engineering Division FJC/pdO6058507 Copy to:
T. P. Johnson, Site inspector S. D. Reynolds, Jr.