AECM-86-0019, Forwards Metallurgical Evaluation of Recirculation Piping Ctr Cross Surface Cracking Following Induction Heat Stress Improvement,Grand Gulf Nuclear Station - Unit 1, Final Rept

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Forwards Metallurgical Evaluation of Recirculation Piping Ctr Cross Surface Cracking Following Induction Heat Stress Improvement,Grand Gulf Nuclear Station - Unit 1, Final Rept
ML20141N884
Person / Time
Site: Grand Gulf Entergy icon.png
Issue date: 03/07/1986
From: Kingsley O
MISSISSIPPI POWER & LIGHT CO.
To: Harold Denton
Office of Nuclear Reactor Regulation
Shared Package
ML20141N885 List:
References
AECM-86-0019, AECM-86-19, TAC-60165, NUDOCS 8603180241
Download: ML20141N884 (2)


Text

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l MISSISSIPPI POWER & LIGHT COMPANY

} Helping Build Mississippi i

RAARMM P. O. B O X 1640, J A C K S O N, MIS SIS SIP PI 39215-1640 March 7, 1986

o. D. KINGSLEY, JR.

U. S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Washington, D. C. 20555 Attention: Mr. Harold R. Denton, Dircctor t

Dear Mr. Denton:

SUBJECT:

Grand Gulf Nuclear Station Unit 1 Docket No. 50-416 License No. NPF-29 Final Report on Recirculation System Cross Cracking AECM-86/0019 The attachment to this letter is the final report on the recirculatier, system cross cracking identified in post-IHSI inspections. A preliminary report was included in a letter dated November 20, 1985 (AECM-85/0372). The purpose of this final report on recirculation system cross cracking is to document the final results of the metallurgical evaluation. As discussed with Mr. Les Kintner of your staff, this final report is submitted to support your review of this matter.

The following significant conclusions are presented in the attached report:

. The defects observed were inherent to the manufacture of the crossec.

. IHSI was not the cause of the defect formation.

. IHSI probably contributed to the opening up of the preexisting defects.

. Tensile tests demonstrated that the near surface defects will not open up under operational or design loads.

. The manufacture of the recirculation crosses was unique and precludes like components exist at Grand Gulf Nuclear Station (GGNS) Unit 1.

If additional information is required, please contact this office.

8603180241 06030/ Yours ly, PDR ADOCK 05000416 P PDR ODK:dmm , g, p!

Attachment 0

x l

cc: See Next Page J14AECM86011501 - 1 Member Middle South Utilities System

AECM-86/0019 Page 2 cc: Mr. T. H. Cloninger-(w/a)

Mr. R. B. McGehee (w/a)

.Mr. N. S. Reynolds (w/a)

Mr. H. L. Thomas (w/o)

'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 Region II 101 Marietta St., N. W., Suite 2900 Atlanta, Georgia 30323 J14AECM86011501 - 2