ML20100R382

Intervenor Exhibit I-52,consisting of Portions of Vol 1 to Transcript of Pr Johnston 840509 Deposition

ML20100R382
Person / Time
Site:	Shoreham File:Long Island Lighting Company icon.png
Issue date:	10/01/1984
From:	Johnston P AFFILIATION NOT ASSIGNED
To:
References
OL-I-052, OL-I-52, NUDOCS 8412170397
Download: ML20100R382 (4)

Text

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.b d' d BEFORE THE ATOMIC SAFETY AND LICENSING I QTRD

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LONG ISLAND LIGHTING COMPANi ) O I O

) Docket No. 50-322-OL (Shoreham Nuclear Power Station )

Unit 1) )

I DEPOSITION OF PAUL R. JOHNSTON tiay 9, 1984 VOLUME I - Afternoon Session e

Reported by:

KEMBLE ANTZ, CSR 669 8412170397 841001 PDR ADOCK 05000322 Q PDR TOOKER & ANT 7 cratorico suomemano memon as see n.amert gentg7 PREDERIC M. TOOMEM ***' C **809 KEMELE ANTZ

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39 1 increase linearly toward the exterior of'the shaft. In fact, 2 the shear stress on a shaf t. is Tau, Greek letter, is equal 3 to the torque amount of twist applied to the shaft times the 4 distance from the center of the shaf t divided by the polar 5 moment of inertia.

6 G Is this in your report?

7 .t Yes, it is.

8 G Can fatiguo cracks occur below the surface?

g A It is possible that they can, yes.

10 0 Under what circumstances can fatigue cracks occur 11 below the surface?

12 A Fatigue cracks might form below the surface if the 13 , stress if higher there or if the material is weaker there.

14 . G In a crankshaft that was not shot poened, under what l

l 15 , circumstances could the material be weaker below the surface 16 than on the surface?

17 ! MS. TARLETZ: Object. The question is very, very broad and doesn't give the witness really enough information 18 l 19 to even define in a limited set of circumstances.

20 MR. SCHEIDT: Can you answer the question?

I j 21 THE WITNESS: If the, as I just mentioned, the 1

22 ; stress would be higher on the surface for a crankshaft, 23 l so if a fatigue crack was to initiate below the surface, it 8

24 would be due to material deficiency.

l 25 MR. SC!!EIDT: O Porosity, could that --

26 ,t It could be.

I 27 G Are there,any detriments to shot peening?

28 MS. TARLET : If any.

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40 1 THE WITNESS: Shot paening puts more emphasis on the t

2 material quality below the surface because of the fact that 3 it imposes a compressive stress region on the surface, those, 4 it may change the area of interest, but to the extent that 5 that is detrimental, it is detrimental. Typically it is not 6 detrimental .

7 MR. SCHEIDT: G What do you mean by change the area 8 of interest?

g A Well, as I mentioned earlier, without shot peening 10 on a shaft, one would expect a fatigue crack to initiate from 11 the surface.

12 As you asked earlier, could a fatigue crack initiate.

13 below the surface and I mentioned that, yes, it could if there 14 was a material deficiency.

15 If now you come and you shot peen the surface, you 16 reduce the likelihood of a fatigue crack initiating on the 17 surface but do not necessarily change the likelihood of 18 defect initiating at, another defect.

19 The conclusion is that shot peening reduces the chance 20 of initiating a crack at the location that it would most 21 likely initiate were it not shot peened.

22 0 Are there any detriments to shot peening?

23 MS. TARLETZ: Objection. I believe the witness has 24 already answered. If you want to define detriment a little 25 bit more carefully perhaps he could continue. But I believe 26 he already answered the question.

27 Ma. SCHEIDT: Have you completely answered the ques-28 tion?

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