ML20046B920

Responds to Request for Addl Info Re Response to GL 92-01, Rev 1, Reactor Vessel Structural Integrity.

ML20046B920
Person / Time
Site:	Duane Arnold
Issue date:	07/30/1993
From:	Franz J IES UTILITIES INC., (FORMERLY IOWA ELECTRIC LIGHT
To:	Murley T NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), Office of Nuclear Reactor Regulation
References
GL-92-01, GL-92-1, NG-93-2800, NUDOCS 9308090023
Download: ML20046B920 (4)

Text

- . - -. - - - - .

. 1:

4 ~8 Iowa Electric Light and Power Company ,

l July 30, 1993 Ul"EldUhlR;,

NG-93-2800 I

Dr. Thomas E. Murley, Director l Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Attn: Document Control Desk  :

Mail Station F1-137 ,

Washington, DC 20555  ;

Subject:

Duane Arnold Energy Center Docket No: 50-331 Op. License No: DPR-49 Response to Request for Additional  ;

Information Regarding Response:to Generic Letter (GL) 92-01, Revision 1,

" Reactor Vessel Structural Integrity"

Reference:

1) NG-92-2816, J. Franz (IELP) to Dr. -,

T. Murley (NRC), dated July 6, 1992 i Request for Additional Information l 2)

Regarding Response to Generic-I Letter (GL) 92-01, Revision 1,

" Reactor Vessel Structural l Integrity" File: A-10lb, B-11

Dear Dr. Murley:

Attached you will find our response to your Staff's request for

-additional information regarding the referenced response by the Duane Arnold Energy Center (DAEC) to NRC Generic Letter 92-01, Revision 1, " Reactor Vessel Structural Integrity".

ll Please contact this office if you require further information regarding this matter.

L 060005 I

930B090023 030730 i PDR ADDCK 05000331 J G -PDR L General of)iw

• P.o. Box 351

• Cedar Rapids, low.a $240G

• 319)398 4411

A

, , j 1

Dr. Thomas E. Murley July 30, 1993 NG-93-2800 Page 2 i This letter is true and accurate to the best of my knowledge and l belief.

IOWA ELECTRIC LIGHT AND POWER COMPANY By N .b '

/ Jo'hn F. ' Frahz Vice President, Nuclear State of Iowa (County) of Linn Signed and sworn to before me on this JO day of Q ev/AJ Y

1993, by ToLn F. F ra. n n .

h*

Notary'Public in and for the State of Iowa ,

RRA M. FRV i

. MY QMMcl0N UMRI3

_. C -J 9 - 9Jr 8 - 2 4 - 9 3~~ >

Commission Expires l JFF/CJR/pjv~

Attachment:

Iowa Electric's Response to NRC Request for Additional Information Regarding GL 92-01, Revision'1, " Reactor Vessel Structural Integrity" cc: C. Rushworth L. Liu L. Root .

R. Pulsifer (NRC-NRR)

J. Martin (Region III)

NRC Resident Office Commitment Control No. 930245 DCRC I

'l l

l 1

t

-> ,- (=  ;

I t

Attachment to l NG-93-2800  !

Page 1 of 2 l IOWA ELECTRIC'S RESPONSE TO NRC REQUEST -j FOR ADDITIONAL INFORMATION REGARDING GL 92-01, REVISION 1, " REACTOR VESSEL STRUCTURAL INTEGRITY" i I

5 Question 2a in GL 92-01 ,

The response to GL 92-01 indicates that the initial upper-shelf energy- l (USE) for two of the four beltline plates and all beltline welds, -!

except for the surveillance weld, are not known. A topical report, i NEDO-32205, titled "BWR Owners' Group Topical Report on Upper Shelf ,

Energy Equivalent Margin Analysis" regarding beltline materials with 1 low USE, was submitted by General Electric Company on April 30, 1993. -

The licensee must either confirm that this topical report will be used  ;

as its licensing bases or provide its plant specific approach to demonstrate that all beltline materials that do not have measured USE ,

will meet requirements of Appendix G, 10 CFR 50.  !

i Iowa Electric Response:

l The DAEC will use topical report NEDO-32205, "BWR Owners' Group  :

Topical Report on Upper Shelf Energy Equivalent Margin Analysis", as DAEC's licensing basis.  ;

t I

Question 2b in GL 92-01 The response indicates that data from the drop weight test and Charpy-  ;

test for beltline materials is either absent or incomplete for initial RT ny determination. An alternative method developed by General ,

Electric (GE) was used in deriving the initial RTgy for these  !

materials. In the GE method, the establishment of the slope for the j transition zone of the Charpy curve is crucial in deriving the initial- l RT gy from incomplete test data. Provide all plate and weld Charpy test curves compiled by GE for establishing the 2 F per ft-lb slope ,

for the transition zone of the Charpy curve. All test data must be from materials equivalent to (i.e., same vendor, fabrication time  !

frame, fabrication process, material specification, etc.) the beltline materials of this react or vessel. . (

i

+

--J

.' L. .  !

Attachment to NG-93-2800 Page 2 of 2 Iowa Electric Response:

The GE method establishes RTum in the following manner: If the lowest longitudinal Charpy energy value determined at a given temperature from a fabrication test is less than 50 ft-lbs, then that value is adjusted upward to 50 ft-lbs and the equivalent test temperature (T33)  ;

is calculated. The slope used by GE for making the adjustment to 50 ft-lbs is 2 F per ft-lb. If the lowest Charpy value is equal to or  ;

higher than 50 ft-lbs, T 33 is assumed equal to the Charpy test temperature. The longitudinal value is then converted to transverse (T 3 ,) by adding 30 F. For weld material, which displays no directionality, T 33 is assumed equal to T 33 The RT ym is then the greater of NDT or (T.,7 - 60 F). l The DAEC did not use that portion of the GE method which utilizes the 2 P per ft-lb slope to derive the RT,3 values. Rather, the RT ym

• values were either set equal to NDT or were based on Charpy energy equal to or higher than 50 ft-lbs at the test temperature, as i tabulated in the table below. ,

IDENTIFICATION g HEAT / lot No. -60 F) NDT DAEC RT,g GE 2*F PER l (T.,f* F ) ._.(

• FJ ._ ('F) FT-LB USED?

Lower Plates (Shell 1) 1-18 c6439-2 38 40 40 No f 1-19 B0402-1 10 40 40 No Lower -

Intermed. Plates (Shell 2) 1-20 B0436-2 10 -30 10 No l i

1-21 B0673-1 10 -30 10 No l Longitudinal Ht. 432ZO471 -50 -

-50 No l i Weld Lot B003A27A

-50 No l I Girth Weld Ht. 071669 -50 -

Lot KG04A27A l 1 - No adjustment necessary. The RT,3 was chosen based on all Charpy values being 2 50 ft-lbs at the test temperature.  ;

.