ML15223A379

NRC000221D - Babcock & Wilcox Report, S-1473-002, Final Report, Rev. 0, Examination of Clevis Bolts Removed from D. C. Cook Nuclear Plant (Dec. 2013)

ML15223A379
Person / Time
Site:	Indian Point
Issue date:	12/31/2013
From:	NRC/OGC
To:	Atomic Safety and Licensing Board Panel
SECY RAS
References
RAS 28145, ASLBP 07-858-03-LR-BD01, 50-247-LR, 50-286-LR
Download: ML15223A379 (15)

Text

NRC00221D Submitted: August 10, 2015 B&W Technical Services Group S-1473-002 66 Figure 41 (continued): Macro and stereo photographs of bolt 2400-7 taken at 450 increments.

B&W Technical Services Group S-1473-002 67 B&W Technical Services Group 5-1473-002 67 icro at 2250 orientation I :Eww *uuL.u iia~

11u 0

Figure 41 (continued): Macro and stereo photographs of bolt 2400-7 taken at 450 increments.

B&W Technical Services Group S-1473-002 68 B&W Technical Services Group S-I 473-002 68 Figure 41 (continued): Macro and stereo photographs of bolt 2400-7 taken at 450 increments.

B&W Technical Services Group S-1473-002 69 cope image Figure 42: Macro and stereo photographs of bolt 300-1 taken at 450 increments.

B&W Technical Services Group S-1473-002 70 B&W Technical Services Group s-I 473-002 70 I

!-1 Macro at 900 orientation at ope image Figure 42 (continued): Macro and stereo photographs of bolt 300°-1 taken at 450 increments.

B&W Technical Services Group S-1473-002 71 B&W Technical Services Group S-I 473-0 02 71 icro at 1800 o ,ntation =Cw IIIIOUW ro at orientation -Itm IIIIOUV Figure 42 (continued): Macro and stereo photographs of bolt 300°-1 taken at 450 increments.

B&W Technical Services Group S-1473-002 72 B&W Technical Services Group S-1473-002 72 cro at 2700 orientation *'1 II*U I I I IIL*I U*IL*U JJIl*

cro at 3156 orientation VIWLP IIII%.Ij Figure 42 (continued): Macro and stereo photographs of bolt 300-1 taken at 450 increments.

B&W Technical Services Group S-1473-002 73 B&W Technical Services Group S-1473-002 73 Figure 43: Wire EDM was used to section each bolt for destructive examinations. The above photo shows initial machining of the threaded region for hardness and tensile testing.

Figure 44: Section photograph for bolt 240°-7 showing the typical locations chosen for subsequent analysis. The five Rockwell C hardness indents are visible on the upper surface of the hardness/tensile blank.

B&W Technical Services Group S-1473-002 74 B&W Technical Services Group S-1473-002 74 Figure 45: ypical location of tensile specirmens machined from each bolt. The IDs of the tested specinhens are shown.

1.000 0.030

-W

-W2k 0.030 W1 = 0.060+/-0.002 (typ. - 4 places) W2 = 0.0005 to 0.0010 greater than W1; with smooth transition from W1 to W2.

Figure 46: Miniature tensile specimen design showing dimensions.

B&W Technical Services Group S-1473-002 75 B&W Technical Services Group S -1473-002 75 Figure 47: Bolt 240-7 after breaking open the crack for SEM/EDS. The two mating halves of the crack are shown. The head side of the fracture (to left) was analyzed by SEMIEDS.

Figure 48: Bolt 300-1 showing plunge cut EDM surface, which removed much of the in-service cracking. Thickness measurements taken around the circumference indicated the EDM was skewed slightly toward the 2700 direction (i.e. to the left in photo).

B&W Technical Services Group S-1473-002 76 B&W Technical Services Group S-I 473-002 76 Figure 49: Macro photograph showing the open crack surface for bolt 120-2. The areas within the white rectangles are shown at higher magnification in the following figures.

B&W Technical Services Group S-1473-002 77 enter oT rigure OU,

B&W Technical Services Group S-1473-002 78 B&W Technical Services Group S-1473-002 79 B&W Technical Services Group S-1473-002 80 B&W Technical Services Group S-I 473-002 80 Figure 56: Macro photograph showing the open crack surface for bolt 120°-6. The areas within the white rectangles are shown at higher magnification in the following figures.