AECM-85-0398, Forwards Info Re Recirculation Sys Cross Forgings in Response to NRC 851203 Request.Encl Util Review Confirms Forgings Unique to Recirculation Sys Crosses

Forwards Info Re Recirculation Sys Cross Forgings in Response to NRC 851203 Request.Encl Util Review Confirms Forgings Unique to Recirculation Sys Crosses

ML20138D397
Person / Time
Site:	Grand Gulf
Issue date:	12/04/1985
From:	Dale L MISSISSIPPI POWER & LIGHT CO.
To:	Harold Denton Office of Nuclear Reactor Regulation
References
AECM-85-0398, AECM-85-398, TAC-60165, NUDOCS 8512130210
Download: ML20138D397 (3)

Text

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EsikhilhilM MISSISSIPPI POWER & LIGHT COMPANY Helping Build Mississippi P. O . B O X 164 0 J A C K S O N, MISSISSIPPI 39215-1640 December 4, 1985 NUCLEAR LICENSING & $AFETY DEPARTMENT U. S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Washington, D. C. 20555 Attention: Mr. Harold R. Denton, Director

SUBJECT:

Grand Gulf Nuclear Station Unit 1 Docket No. 50-416 License No. NPF-29 Recirculation System Cross Forgings AECM-85/0398 As requerted in a telephone conversation on December 3, 1985, with the NRC Staff t! 3ttached information is provided. This information addresses the question sr whether additional forgings similar to the recirculation system crosses exist at Grand Gulf Nuclear Station (GGNS) Unit 1. The attached information provides the results of Mississippi Power 6 Light's (MP6L) review and confirms that the subject forgings are unique to the recirculation system crosses.

If any additional information is required, please contact this office.

Yours truly, L. F. Dale Director CCS/MLC/JGC:dem Attachment cc: Mr. O. D. Kingsley, Jr. (w/a)

Mr. T. H. Cloninger (w/a)

Mr. R. B. McGehee (w/a) 8512130210 851204 Mr. N. S. Reynolds (w/a) PDR ADOCK 05000416 Mr. H. L. Thomas (w/o) P PDR Mr. R. C. Butcher (w/a)

Mr. James M. Taylor, Director (w/a)

Office of Inspection & Enforcement U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Dr. J. Nelson Grace, Regional Administrator (w/a)

U. S. Nuclear Regulatory Commission l

Region II ,o k 101 Marietta St., N. W., Suite 2900

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Atlanta, Georgia M14$Sr Middle South Utilities System \

J14AECM85120401 - 1

t l ATTACHMENT TO AECM-85/0398 Page 1 of 2 The rebirculation system 24" x 16" crosses are SA-403 WP304 with a base material of SA-182 and are supplied by Taylor Forge. SA-403 is a speci-fication for the forming of fittings from other preexisting materials (e.g.

SA-240, SA-182, SA-376), and not a material specification in itself. The size and thickness of the crosses makes them unusual for the forging process, and would require a mill to establish unique processes and tooling I for their manufacturing. Normal forging operations are performed by a hammer, press, forging machine, or forging rolls. The attached figure indicates that a normal forging process was only used in the early stages of the component and that the actual forming was performed by a back extrusion and expansion process. In other words, the crosses are not a catalog fitting or shelf item, and assembly line processes were not appli-cable. _

SA-403 is a common material as described in the design documents (NON-NSSS) of GCNS. For ASME Class 1 fittings greater than 8", and ASME /

Class 2 and 3 fittings greater than 10", SA-403 WP304W is specified. The "W" suffix of 304W indicates that it is a welded fitting (fabricated); and is normally fabricated / welded from formed SA-240 plate, thus the forging process is not used. The use of a forged base product in the smaller diameters is not precluded, but with the thickness associated with these 1

. smaller diameters and the BWR design, normal forging operations would be used.

.l, ASME Class 1, 2, and 3 stainless steel flanges as described by CGNS (

design documents are SA-182 and are manufactured by the simplest forging process. Large diameter flanges are of the weld neck design and both the I.D. and 0.D. surfaces are machined.

A review of the recirculation system has identified the crosses, 16" end caps and the 16" x 12" header to riser sweepolets as the only significant forgings. The sweepolets and end caps, though large, are still simple forgings and would not require special tooling or process development for their manufacturing. Other major fitting (e.g. elbows, tees) are manufactured from formed plate (SA-240).

I Based on the above it is concluded that no like components exist in the Unit I installation.

In the unlikely event that grain boundary anomalies did exist in other components, they would not be discernible until the tensile stresses induced by IHSI are employed to aggravate the preexisting condition. The non-IHSI treated anomalies would exist on a micro scale and require 0.D. surface tensile stresses substantially higher than what is typically seen during plant operation to aggravate the anomalies into becoming discontinuities.

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