JPN-88-043, Forwards Info in Support of Util 880816 Response to Generic Ltr 88-01 Re IGSCC Program at Plant,Including Rev 1 to SIR-87-015, Welds II Residual Stress Analysis of Resistance Heating Stress Improvement Welded Pipes

Forwards Info in Support of Util 880816 Response to Generic Ltr 88-01 Re IGSCC Program at Plant,Including Rev 1 to SIR-87-015, Welds II Residual Stress Analysis of Resistance Heating Stress Improvement Welded Pipes

ML20207H765
Person / Time
Site:	FitzPatrick
Issue date:	08/19/1988
From:	Brons J POWER AUTHORITY OF THE STATE OF NEW YORK (NEW YORK
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
Shared Package
ML20207H770	List: JPN-88-043, Forwards Info in Support of Util 880816 Response to Generic Ltr 88-01 Re IGSCC Program at Plant,Including Rev 1 to SIR-87-015, Welds II Residual Stress Analysis of Resistance Heating Stress Improvement Welded Pipes ML20207H793 ML20207H829
References
RTR-NUREG-0313, RTR-NUREG-313 GL-88-01, GL-88-1, JPN-88-043, JPN-88-43, NUDOCS 8808300028
Download: ML20207H765 (10)

Text

. .

123 Main Street White Plains, New York 10601 914 681.6240 4 NewYorkPower seso c. s<oo.

1# Authority Nucicar Generation August 19, 1988 JPN-88-043 U. S. Nuclear Regulatory Commission Mail Station Pl-137 Washington, D.C. 20555 Attn: Document Control Desk

Subject:

James A. FitzPatrick Nuclear Power Plant Docket No. 50-333 Resistance Heating Stress Improvement

References:

1. NYPA Letter, C. A. McNeill to D. B. Vassallo, dated October 25, 1984.

2. NYPA Letter, J. C. Brons, to NRC dated August 16, l 1988 (JPN-88-041) responded to Generic Letter 88-01.

Dear Sir:

This letter is submitted in support of our response to Generic Letter 88-01. In 1984, as part of a comprehensive Intergranular Stress Corrosion Cracking (IGSCC) program at the FitzPatrick plant, the New York Power Authority applied Induction Heating Stress Improvement (IHSI) to all but two Reactor Recirculation System Welds (Reference 1). These two circumferential welds, located under pipe whip restraints, lack the necessary radial clearances for IHSI heating coils.

To protect these remaining two welds and, thus, the entire Recirculation System, the Authority developed and used resistance heating stress improvement (RHSI). A patent application has been submitted for this process.

To demonstrate RHSI effectiveness and to develop field ready equipment, the Authority performed tric1 heats on two ,

different 28 inch diameter piping sections, followed by  :

through-wall residual stress measurenents. I During the Spring 1987 refueling outage, the Authority applied RHSI to the previously untreated welds, 28-02-2-50 and T,8 - 0 2 10 8 . Attachments 1, 2, and 3 contain the results and analysis for the two welds, showing the stress improvement obtained. Even allosing for conservative assumptions regarding temperature and stress distributions, RHSI developed temperature gradients sufficient to create substantial compressive stresseF in the inner portion of the pipe wall, f 8808300028 880819 s DR ADOCK0500g}3

O The Authority considers that the RHSI process-is an effective IGSCC mitigating technique and that the welds treated by this process are protected.from IGSCC.

In accordance.with NUREG-0313 Revision'2, these welds have-been moved.from inspection Category D to Category C (Reference-

~

2). They are scheduled for examination accordingly.

Should you or your staff have cnyJguestions regarding this; matter, please contact Mr. J. A. Gray, Jr. of my staff.

Very truly yours, A_

ohn C. Brons xecutive Vice President duclear Generation Enclosures cc: U. S. Nuclear Regulatory Commission Region I 475 Allendale Road King of Prussia, PA 19406 Office of the Resident Inspector U. S. Nuclear Regulatory Commission P. O. Box 136 Lycoming, New York 13093 Mr. Harvey Abelson Project Directorate I-l Division of Reactor Projects - I/II U.S. Nuclear Regulatory Commission Mail Stop 14B2 Washington, DC 20555 i

a i

p , ,

- rl r.

i _ _

-)

. *- 1 u i i.

-l JPN-88-043 ATTACHMENT 1

• i I

, :l

_-i

~

, :l I

t 9

4 l-I l t i

1 i

f A >

i

, F

)  !

1 .

j- i t ,

f New York Power Authority i j

James A. FitzPatrick Nuclear Power Plant i, Docket No. 50-333 '

DPR-59 i I t i

i

}

i i

i I i

i 1

I f n-_ . - _ - - - - . . - , - - _ _ _ _ .

s ATTACHMENT 1 RESISTANCE HEATING STRESS IMPROVEMENT Following initial proof testing of Resistance Heating Stress Improvement'(RHSI), the Authority conducted more complete qualifying' testing. This consisted of welding:a 28" outer .;

diameter pipe joint according to industry standard-practice

~

for Class I welds at the FitzPatrick plant, developing a through-wall. temperature gradient by resistance heating, and obtaining through-wall residual stress measurements. These stress measurements were used to calibrate a finite-element model by;which field RHSI treatments would be evaluated.

After this testing was completed and evaluated, RHSI was applied to the field welds 28-02-2-50 and 28-02-2-108.in the '

Reactor Recirculation System. -This field application used the same heater used in the initial proof test. Attachmen't 2 i contains a description and sketches of this resistance heater.

Attachment 3 is the final report on the RHSI process. It-includes two reports:

I e stress analysis _ prepared by Structural Integrity on residual stress following RHSI, and e a report of experimental determination of residual stresses following RHSI.

Attachment 3 also includes pertinent correspondence. The stress analysis considers applying RHSI to a test pipe'under laboratory conditions, doing a destructive residual stress determination on the laboratory pipe, and-applying RHSI to recirculation system welds 28-02-2-50 and 28-02-2-108. In all cases, sufficient temperature gradients were developed to create compressive stresses of substantial magnitude in the inner portion of the pipe wall, even allowing for the conservative assumptions made regarding temperature-and stress distributions. The report also concludes that when the design temperature gradient and temperature band size are achieved, the results are not significantly affected by initial residual stresses. Finally, the report shows that RHSI is reasonably tolerant of deviations from the optimal design temperature distribution, if the deviations are of a local nature. The Authority considers RHSI an effective integranular stress corrosion cracking (IGSCC) mitigating technique and, thus, the welds treated by this process are not subject to IGSCC. )

i a

ATTACHMENT 1 RESISTANCE HEATING STRESS IMPROVEMENT Following initial proof testing of Resistance Heating Stress Improvement (RHSI), the Authority conducted more complete qualifying testing. This consisted of welding a 28" outer diameter pipe joint according to industry standard practice for Class I welds at the FitzPatrick plant, developing a through-wall temperature gradient by resistance heating, and-obtaining through-wall residual stress measurements. These stress measurements were used to calibrate a finite element

~

model by which field RHSI treatments would be evaluated.

After this testing was completed and evaluated, RHSI was applied to the field welds 28-02-2-50 and 28-02-2-108 in the Reactor Recirculation System. This field application used the same heater used in the initial proof test. Attachment 2 contains a description and sketches of this resistance heater.

Attachment 3 is the final report on the RHSI process. It includes two reports:

e stress analysis prepared by Structural Integrity on residual stress following RHSI, and e a report of experimental determination of residual stresses following RHSI. )

l Attachment 3 also includes pertinent correspondence. The i stress analysis considers applying RHSI to a test pipe under l laboratory conditions, doing a destructive residual stress determination on the laboratory pipe, and applying RHSI to recirculation system welds 28-02-2-50 and 28-02-2-108. In all cases, sufficient temperature gradients were developed to create compressive stresses of substantial magnitude in the inner portion of the pipe wall, even allowing for the conservative assumptions made regarding temperature and stress l distributions. The report also concludes that when the design temperature gradient and temperature band size are achieved, the results are not significantly affected by initial residual stresses. Finally, the report shows that RHSI is reasonably tolerant of deviations from the optimal design temperature distribution, if the deviations are of a local nature. The Authority considers RHSI an effective integranular stress corrosion cracking (IGSCC) mitigating technique and, thus, the welds treated by this process are not subject to IGSCC.

j' ^

J JPN-88-043 ATTACHMENT 2 4

( ,

J ll i

1 New York Power Authority James A. FitzPatrick Nuclear Power Plant 4

' Docket No. 50-333 DPR-59 l

1 e

h 4

- - -~~ . - _ _ _ _ _ _ _ . _ . _ __ _ _ _ _ _ _ _ _ . _ _ __ _ _ _ _ _ _ _ _ _ _ _ _

l O

, RESISTANCE HEATING STRESS IMPROVEMENT

. HEATER DESCRIPTION Shell:

Material: Stainless Steel Dimensions: 28"id x 31"od x 24" Shell Insulation:

Vacuum-formed boards Material: High purity alumina & silica Sprayed with calcium silicate Adhered to shell with ceramic fiber cement.

Ceramic Bead Material: 95% AL 023 & Silica Support Rod Material: 99.9% Tungsten Rivet Material: Stainless Steel Push Nut Material: Zinc plated steel Heating Wire Material: Iron-chromium-aluminum i

Cold Tail Wire Material: 99% nickel braided wire Cold Tail Terminal Material: Stainless Steel 3 Phase Electrical Buss Material: Pure copper Electrical Connector Material: Brass Thermocouple:

Type "K" Sheath Material: Inconel Connector Material: Thermoplastic Thermocouple Tie Down Strap Material: Stainless Steel Power Rating: 252 KW G480VAC, 3 phase, 60 Hz Electrical Cables: 600V Neoprene insulated Cable Connectors: Brass with 600V Neoprene insulator k

. cr.6 D...... ...oATr..%).a.7 cu:urcr R.td.5.T...../ &..'.'.dEATEa .

cw cer uo .. . ....-.or c n n o. a r. .... .. o Ar a..... YA.LREC0 ..ENEtxX.... con.u'ERSXaN .ooe uo.84.. .4L).% c-/n=% ,

A O

ccPern euss SHEL L

.O X - SEC TIONA L VIC W \

SHEU INSUL A TION 4 No7' 7'o SCALE CERAMIC BEA D %

(- . -

h o HEA TING WIR E i

C ER AMEC * ->

con 21,,

// "< ~ ~

w t

T O

y

• h L ,

% c i

3 k U 3

V o '.'

+i 3r t

r

' 480YAC 3 PHASE POWER

' < 11" HEAT BAND COPPER BUSS BARS 1r 1r u l

a A n A a A a A a A a A e. A A  :

41i1\l i 1 \. l \. \ \. l ( F yv v v v v v v v v v v f

i

_ _ ____________/  !

M 1 \.1 \ l \ 1 \ l \ l i l i )

v v v v v V W v v v v v v q IA A A A A A A A A A A A A A & ,

M1\li1\1\l\\\l\

~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ F ~ ~  !

_____________/  !

M ,1 \. l i 1 \. l \ l \ l \.1 \ >

v v v v v v v v j

-i. l \ \ \. l \. l i 1 i 1 \ l \. fb-v v v v v . v v v v v

. -__. -_.. .../  :

-{ l \ l \ l

/.v v v v v \ l i v v v v v v 1 \ l i.1 v i. y F l

..___. ._-.... N.

l \ l \ \. \. \, \ \ \ l \. l. \. J}-

v v v y v v v  !" HEATER ELEMENT A A A A A A A A A A A A i i 1 \ \. \. l \ \ \. l i 1 i. >

v v v v v v v INSULATED INSULATED l

l l

l l

l l

SECTION A-A l

N.T.S. '

SEGMENT OF THE HEATER Valr/co Energy Convers/on

( Tecimology Company

6 JPN-88-043 ATTACHMENT 3 l

l l

i l

l l

I l

New York Power Authority James A. FitzPatrick Nuclear Power Plant i Docket No. 50-333  !

DPR-59

.