ML20042B460

Final Deficiency Rept Re Fissuring Problems W/Stainless Steel Cladding in Reactor Bldg Suppression Pools,Initially Reported 801006.Fracture Fatigue Analysis Performed.Coating Sys to Prohibit Crevice Corrosion Will Be Employed

ML20042B460
Person / Time
Site:	Perry
Issue date:	03/15/1982
From:	Davidson D CLEVELAND ELECTRIC ILLUMINATING CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20042B461	List: ML20042B460 ML20042B462
References
10CFR-050.55E, 10CFR-50.55E, RDC-19(80), NUDOCS 8203250336
Download: ML20042B460 (2)

Text

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THE CLEVELAND ELECTRIC ILLUMIN ATING COMPANY P O Box 5000 e CLEVELAND. OHIO 44101 e TELEPHONE (216) 622-9800 m ILLUMINATING BLOG e 55 PUBLIC SOUARE Serving The 4 a S&* c h the Nation N

D:lwyn R. Davidson VtCL F'HE SIDt NT March 15, 1982 @

$ YST[ M [hG!NE E R!NG AND CON 5f HUCTION 8'd h,@ k.i g G.

MAR 2 41982> O a nn wnn m

n '3 Mr. James G. Keppler - IM3I *4LLU EI Director, Region III ,

9 Office of Inspection and Enforcement b U. S. Nuclear Regulatory Commission m W 799 Roosevelt Road Glen Ellyn, Illinois 60137 RE: Perry Nuclear Power Plant Docket Nos.

50-440, 50-441; Significant Deficiency Suppression Pool Stainless Steel Cladding Sensitization (RDC 19(80))

Dear Mr. Keppler:

This letter, together with the Gilbert Associates' " Perry Stainless Steel Cladding Evaluation Report," Number 2388, dated March 1982, constitutes the Final Report as required by 10CFR50.55(e) on the fissoring problems in the Reactor Building Suppres-sion Pools of Units 1 and 2. This was first reported by Mr. M. R. Edelman of The Cleveland Electric Illuminating Company to Mr. J. E. Konklin of your office on Octo-ber 6, 1980. The subject was amplified in the Interim Report dated November 12, 1980.

This Interim Report describes the deficiency, background information and planned cor-rective action at that time.

This report gives a description of the problem and investigations undertaken, summary and resolutions.

ACTION TAKEN SINCE Tile INTERIM REPORT A detailed evaluation was made of the extent of fissuring, including:

1. On containment and drywell vent structures, stretch-out drawings, mill certs were correlated to plate locations. This pinpointed the physical properties and carbon content of each plate to an exact location within the structure.

2. Penetrant examina ion was performed on a selected sample basis for the entire containment shell and drywell vent structure weld joints, heat-affected zones, and base plates to determine the extent of fissuring in the plate material and weld seams.

3. Aptech Engineering Services, engineering consultants, developed a fracture mechanics model of the containment vessel and drywell vent structure to determine whether crack propagation would have detrimental structural rami-fications.

KOo ho NION 4m9

I Mr. J mes G. Keppler March 15, 1982 Page Two

4. Coating systems were evaluated for protection of the carbon steel overlayed by the fissured cladding.

ANALYSIS OF TIIE SAFETY IMPLICATIONS

1. The attached " Perry Stainless Steel Cladding Evaluation Report" supports the supposition that no adverse structural implications are associated with fissuring.

2. The implications of crevice corrosion would have posed the possibility of con-tainment breach, thus resulting in potential off-site exposure exceeding allowable limits.

CORRECTIVE ACTION

1. A fracture fatigue analysis was performed to assure no adverse consequences would arise from the fissuring in the suppression pool cladding.

2. Although crack propagation from the fissuring is not a problem, a coating system to prohibit crevice corrosion will be employed. This will consist of an aluminum flame spray with an epoxy topcoat.

3. The Perry Project will implement an in-service monitoring program in which both cocted and uncoated specimens will be placed in suppression pool environment and periodically examined to determine coating durability and corrosion-notch progression.

Sincerely, I

had . y Dalwyn R. Davidson, cc President System Engineering and Construction cc: Mr. M. L. Gildner NRC Site Office Mr. Victor Stello, Director Of fice of Inspection and Enforcement U. S. Nuclear Regulatory Commission Washington, D.C. 20555 U. S. Nuclear Regulatory Commission c/o Document Management Branch Washington, D.C. 20555