ML18078A998
| ML18078A998 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 11/20/1978 |
| From: | Martin T Public Service Enterprise Group |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| Shared Package | |
| ML18078A996 | List: |
| References | |
| NUDOCS 7903140075 | |
| Download: ML18078A998 (3) | |
Text
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Thomas J. Martin Pub I ic Service Electric and Gas Company 80 Park Place Newark, N.J. 07101 201 /430-8316 Vice President Engineering and Construction Mr. Boyce H. Grier, Director U.S. Nuclear Regulatory Conunission Region 1 6 31 Park Avenue King of Prussia, Pennsylvania 19406
Dear Mr. Grier:
NRC INSPECTION 50-311/77-26 SUPPLEMENTAL INFORMATION NO. 2 UNIT SALEM NUCLEAR GENERATING STATION November 20, 1978 In our memorandum of May 9, 1978, we outlined actions taken and proposed to confirm the integrity of those weld joints that were not heat treated in full accord with ANSI B31.7.
As stated in that letter, NDE would be performed on three of those welded joints during hydrostatic testing.
Also, a severe heat treatment along with NDE and mechanical tests would be performed on surplus main steam piping at Salem.
This testing has been completed and a summary of the tests and results follows.
From these tests and our experience
- with the heat treatment procedure, we conclude that. the--hec::iar"l"t~---~
treatmen~, al though not in full accord with Ai.'\\l'SI B31. 7 had no detrimental effect on the Salem Piping.
Heat Treatment Test For information and reference purposes, a heat treatment was performed on surplus main steam piping.
The pipe was A-155 KC 70, 1-1/8".thick, 30" diameter and 20 feet in length with an existing circumferential weld at the center and welded longitudinal seams.
The pipe was oriented in the horizontal position with one of the longitudinal seams at 12 o'clock.
The circumferential. seam was heat treated in accordance with the following parameters:
790314001S-Heating Rate -
6400F/hour Maximum temperature change in 5 minutes 73° (heating)
Peak Temperature -
13300F Maximum Cooling Rate -
840°F/hour Maximum temperature change in 5 minutes -
53° Holding time -
40 minutes at 12000F
'~Boyce H. Grier 2 -
- 11/30/78 These heating and cooling rates are far in excess of those allowed by ANSI B31.7.
Before and after heat treatment, hardness readings were taken and magnetic particle, radiographic and ultrasonic testing were performed.
During the heat treatment, acoustic monitoring was performed.
Several sections of interest were removed from the pipe for metallurgical (microetch) and mechanical testing (tensile, bend, impact).
The acoustic* emission test located ten sources (four Grade B and six Grade C), none of which were* considered rej ectable.
In accordance with a proposed ASME standard, the sources were classified as follows:
Grade A - If it occurs during pressure build-up, pressurization should be halted.
Confirm results as relevant by other nondestructive examination methods.
Grade B -
Recordabl.e and reportable for future comparison.
Grade C - Further evaluation or correlation not required.
lthough not a pressure test, the above criteria was applied to the heat treatment test~
The six Grade C sources were dismissed with no furth~r action required and other methods of NDE were.
recommended for investigating the four Grade B sources.
Ultrasonic, radiographic and magnetic particle testing were used to investigate the Grade B sources and other areas of the pipe.
Magnetic particle and radiographic testing did not locate any defects generated by the postweld heat treatment.
Ultrasonic test~ng* only located insignificant and geometric indications.
- There was no significant difference in the'mechanical tests from heat treated and non-heat treated areas.
Microetch.tests revealed no defects.
Hydrostatic Test
- The heat treatment charts.. of those joints from Units 1 and 2 that were.not heat treated in accordance with ANSI *B31.7 were reviewed.
Three joints representi'ng the more excessive heating and cooling rates were selected for acoustic monitoring during hydrostatic testing.
These joints ranged in thickness from 1 to. 3. 75 inches.
For comparison, another joint th.at *was heat treated in accordance with ANSI B31.7 was monitored
- rior to hydrostatic testing, the joints were magnetic particle nd ultrasonically tested.
Hardness readings were taken before hydrostatic testing and showed normal levels of hardness for the material.
Acoustic monitoring was performed during hydrostatic testing and ultrasonic testing was performed again after hydro-static testing.
-*oyce H. Grier 2 -
11/20/78 Acoustic monitoring located ten sources, seven of which were Grade c and three Grade B.
Ultrasonic testing of *the joints and Grade B sources revealed both insignificant and geometric indications with no apparent changes in the before and after tests.
The magnetic particle test before hydrostatic testing revealed no recordable indications.
This testing represents a thorough investigation of the postweld heat treatment problem and adequately demonstrates the integrity of the Salem main steam piping.
Complete test results of the above will be available at the Salem site for your.review during the week of December 4, 1978.
If you require any additional information, we will be pleased to discuss it with you.
Very truly yours,