ML20085L533

Forwards Addl Info Requested Re Util Application for Amends to Licenses NFP-37,NPF-66,NPF-72 & NPF-77.Amends Would Increase IPC Value to 3.0 Volts

ML20085L533
Person / Time
Site:	Byron, Braidwood
Issue date:	06/20/1995
From:	Saccomando D COMMONWEALTH EDISON CO.
To:	Office of Nuclear Reactor Regulation
References
NUDOCS 9506280549
Download: ML20085L533 (84)

Text

-

Q>mmonwealth fihson Q2mpany 1400 Opus 11 ace

.. a Downers Gnnc, IIE)515 June 20,1995 Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission i

Washington, D.C. 20555 Attn: Document Control Desk

Subject:

Additional Information Pertaining to the to Application for Amendment to Facility Operating Licenses:

Byron Nuclear Power Station, Units 1 and 2 i

NPF-37/66: NRC Docket Nos. 50-454/4fifi Braidwood Nuclear Power Station, Units 1 and 2 NPF-72/77: NRC Docket Nos. 50-456/457 i

" Steam Generators"

Reference:

D. Saccomando letter to Nuclear Regulatory Commission dated February 13,1995, transmitting Proposed Technical Specification Amendment Regarding Increase in the IPC Criteria The Reference Letter transmitted Commonwealth Edison Company's (Comed's) proposal to amend Appendix A, Technical Specifications of Facility Operating Licenses NPF-37, NPF-66, NPF-72 and NPF-77. The proposed amendment request addresses Technical Specification changes necessary to increase the Interim Plugging Criteria (IPC) value for Braidwood and Byron Station Unit 1 Steam Generators from 1.0 volt to 3.0 volts.

Subsequent to that submittal, Comed and the Nuclear Regulatory Commission i

(NRC) met on February 23,1995, to discuss the submittal. During that meeting Comed presented a model which addressed leakage from indications restricted from burst (IRBs). After discussions, Comed pursued the development of an alternate leak rate model along with a test program to support the alternate leak rate model.

Recognizing that the Staff has been actively reviewing our amendment request and that outstanding technical issues may still exists, Comed is providing the Staff with additional technical justification supporting the 3 volt IPC request.

' outlines the development and the available results of a Comed /EPRI sponsored test program which determined the bounding leak rate value of an IRB by the presence of the tube support plate. The test program is in progress and is scheduled to be completed and final results available by July 15, 1995.

I o ni. w m.o n m.. m

(

()0 9506280549 950620 PDR ADOCK 05000454 1

P PDR I (

)

A l'nicum Compa

NRC Document Control Desk June 20,1995

- contains:

i Section I:

History and Test Program Objective Section II:

Total Test Program Development and Evaluation of Test Variables Section III: Proposed Testing Plan Section IV: Test Specimen Results (Summary and Conclusions)

Comed has reviewed the results of the bounding IRB test program proposed to the NRC on April 3,1995. This is nearing completion and the final report will be transmitted to the NRC by July 15,1995. Based upon Commonwealth Edison's review of this new information, the following conclusions have been reached:

The free span leak rate calculation methodology approved for ODSCC at the tube support plate, provides sufficient conservatism for use with a calculate leak rates with 3.0 volt IPC. contains the detailed comparison ofIRB and free span leak rate methodologies. Comed has calculated anticipated leak rates, end of cycle, using Braidwood 1 data, using both the free span and IRB leak rate 3

methodology and finds that similar results are obtained. These results indicate that the conservatism built into the IPC leak rate calculation methodology are adequate, with 3 volt IPC.

]

Comed has concluded that the application of an improved probability of detection (POD) algorithm is unnecessary to support the Byron 1 and Braidwood 1 Technical Specification Amendment.

Comed believes it is necessary to more clearly understand the ability of eddy current to detect and size steam generator tube defects. This understanding will support a new POD as proposed by Comed. However, in the interest of expediting the review of the Comed request for Byron 1 and Braidwood 1, a POD of 0.6 will be used with the 3 volt IPC, until changed by industry activities.

The data provided in Attachment 1 are the latest final results and clearly demonstrate that extraordinary large leakages should not be anticipated even with substantial offset of the crack outside of the tube support plate.

R :nle :9ybwd i f!tgen/ 2 msT 2

I NRC Document Control Desk June 20,1995 The bounding leak rate determined as a result of this test program is 4.7 gpm, for a 0.74" long crack extending outside the support plate 0.10". As discussed in meetings with the NRC on February 23, April 11, and May 9, Comed believes that it has succeeded in producing a test specimen with crack length equal to the thickness of the support plate and tested its leak rate. With the other conservatism assumed as part of other elements of the Technical Specification Amendment, Comed has concluded that the 4.7 gpm indeed represents the bounding leak rate for a 3/4" diameter tube with a long crack. Based upon this, Comed has determined that review of the leakage model in Sections 9.7 and 9.8 of W' CAP-14273 is nic longer necessary.

Comed is currently preparing a supplement to our February 13,1995, submittal, that will incorporate information contained in the Generic Letter as well as the data contained in Attachments 1 and 2 of this letter. This supplement, which will supersede that transmitted in the Referenced letter, will be submitted to the Staff shortly.

To the best of my knowledge and belief, the statements contained in this document are true and correct. In some respects these statements are not based on my personal knowledge, but on information furnished by other Comed employees, contractor employees, and/or consultants. Such information has been reviewed in accordance with company practice, and I believe it to be reliable.

Comed and the NRC have tentatively scheduled a meeting on June 27,1995, to further discuss these results, in the interim, if you have any questions concerning this correspondence, please contact this office.

T ppjC U 5 U

{$

Sincerely, MARY JO YACK 4

/.

')7

[

$ NOTARY PUBUC ST ATE oNLUNOIS

/

n,J4 k."!.??".T"'?."2"."!.*:11'!.*.9! f Denise M. Sacc,oniando Nuclear Licensing Administrator T) n,.,,, m g/g 4 $.20 ff

< ( y (. ;

cc:

D. Lynch, Senior Project Manager-NRR R. Assa, Braidwood Project Manager-NRR

'f G. Dick, Byron Project Maanger-NRR S. Dupont, Senior Resident Inspector-Braidwood H. Peterson, Senior Resident Inspector-Byron OfTice of Nuclear Safety-IDNS E inla : Byt7wd:Steen/IPcTest:3

Attachment 1

Indications Restricted From Burst Test Program (Latest Final Results) l This attachment outlines the development and results of a Comed / EPRI sponsored test program to determine the bounding leak rate value of an indication which has been restricted from burst (IRB) by the presence of the tube support plate (TSP). Specifically this attachment contains-

- Section I History and Test Program Objective

- Section II Total Test Program Development and Evaluation of Test Variables

- Section III Proposed Testing Plan

- Section IV Test Specimen Results (Summary and Conclusions)

{

1 l

i 4

E.stle < Pytd St gen / 2 PC" rest: 4

Section I History On February 23,1995, Comed and the NRC met to discuss the potential increase l

of the interim plugging criteria for 3/4" tubes from 1.0 volt to 3.0 volts until steam generator replacement at Braidwood 1 and Byron 1. During that meeting Comed presented a model which quantified the low probability which exists for indications that may potentially " leak" within the confines of the TSP at pressures equal to main steam line break (MSLB) pressure.

At the Staffs request, Comed provided the Staff with data which would quantify l

the potential benefit from using this analytical leakage model. Additionally, I

Comed also pursued the use of an alternate leak rate model which did not rely on a bobbin voltage correlation with crack length. A description of this model and results quantifying the potential benefits were provided to the Staffin Reference 2.

To fully support the alternate leak rate model, it is necessary to define a fixed leak rate for a single indication restricted from burst (IRB) by the presence of the TSP. One approach is to define an IRB bounding leak rate and apply that leak l

l rate to each IRB independent of size. In an effort to obtain a bounding leak rate I

for IRB, Comed submitted a proposed laboratory test program to the Staffin Reference 3. This proposed laboratory test program used 7/8" diameter tubing specimens with throughwall outside diameter stress corrosion cracking (ODSCC) crack lengths of 0.34",0.40" and 0.50". These specimens would be pressurized to approximately 15% above calculated burst pressure while contained within a simulated support plate. Leak rate measurements would then be performed at both room and operating temperature.

The development of this phase of the test program was based upon samples immediately available for testing. Specifically, our decision to use 7/8" diameter specimens with 0.34",0.40" and 0.50" ODSCC crack lengths, rather than the Byron and Braidwood size 3/4" diameter tubing was because of specimen availability. Laboratory induced ODSCC specimens take several weeks to generate. Furthermore, it is Comed's position that the leak rate is a geometrical function that is not dependent on the tube diameter. To demonstrate this, testing includes both 3/4" and 7/8" diameter tubing.

In early April the plan and the preliminary results from this test program were reviewed by the EPRI SGDSM Ad-Hoc committee. Modifications to the test plan, i

as well as the leak rate calculation, were made based upon suggestions from the committee.

F:nle:Pytwd-$tgen/IPCtesT:$

i

1 On March 22,1995, the Staff and Comed participated in a teleconference to l

discuss this test program (Reference 3). During that teleconference, Comed j

recognized that the proposed test program needed to be enhanced to address new concerns.

Based upon these concerns Comed proceeded with the following actions:

1.

Redefine objectives of a new and expanded laboratory leak rate test program.

{

2.

Develop a list of required test variables to meet the leak rate test program objectives.

3.

Develop a parametric sensitivity study test matrix based upon the list of variables.

4.

Develop a detailed prio itized test program to bound variables of the

+

parametric sensitivity study.

5.

Define a final test plan to meet test objectives, i

4 i

]

I F inla : Dylwd: Stgen /IPCTesT:6

e Section II TOTAL TEST PROGRAM DEVELOPMENT Test Plan Obiective Develop a bounding MSLB leak rate for large (>0.6") indications which have been restricted from burst (IRB) by the presence of the tube support plate (TSP). This bounding leak rate value will be used in a leak rate calculation which takes into account both freespan and IRB leakage.

Comed does not have an objective to create or test a low voltage (1 volt or less) 3/4" long crack. However, long cracks (>0.6") will be created and tested.

Variables Considered in total test program As part of Comed's development of a total laboratory test program from which a bounding test program was derived, the following variables were taken into consideration.

Leak rate sensitivity to:

Tube size Crack length Test temperature Crevice condition TSP gap Crack exposure outside TSP Tube pressurization at pressures up to freespan burst Freespan to IRB leak rate comparison i

Tables 11-1 and II-2 define the elements of a total parametric study which would l

be required if all these variables were tested for each possible combination.

I I

F:nla,Bybwd;Stgen/IPCteaT:7 1

l Comed's Evaluation of Test Variables Comed performed an evaluation of all the possible test variables and determined which are important to the bounding test program. The following is a description of how we addressed each variable in the test program.

Sensitivity to tube size Byron and Braidwood Unit 1 tubing is 3/4" diameter. Due to the immediate availability of 7/8" tubing corrosion test specimens, the test program was begun using 7/8" tubing. These test results were used to define additional testing requirements and test modifications. Subsequent testing included 3/4" diameter tubir.g.

j A review of the geometry of the hypothetical crack is contained within WCAP-14273. It is important to note that for an IRB, the equations provided to define the crack opening area depend upon the length of the crack, and the gap between the outside diameter of the tube and the inside diameter of the tube support hole.

In addition, the WCAP describes the basis upon which the maximum clearances between hole and tube were assembled. This leads to the fact that the calculation of the crack opening area is based on geometric equations. Review of these equations indicates that there is no dependency of the crack opening on tube diameter.

To demonstrate that the leak rate is a geometrical function of crack opening and is not dependent on tubing diameter, Comed performed testing on both 7/8" and 3/4" diameter tubing. Based upon the similar test results it is not necessary to do duplicate testing with both 7/8" and 3/4" similar tubing.

Sensitivity to crack lencth:

Specimens were prepared for 3/4" diameter tubing with a goal of achieving throughwall crack lengths in the following ranges; 0.25" - 0.45", 0.45" - 0.60" and 0.60" - 0.75", Use of these ranges will develop a conservative upper bound leak rate based on the following facts:

No iadications below 10 volts have had a throughwall crack >0.37" per the EPRI pulled tube database.

Braidwood 1 and Byron 1 largest indications of 10.3 and 10.9 volts had throughwall crack lengths of 0.20" and 0.27", respectively, with burst pressures

> 4000 psi at operating temperature. This is well within the experience of the EPRI pulled tube database.

.,a. w m cr.. a

)

The critical throughwall crack length for a burst at MSLB pressure of 2560

'l y

~*

psid for a 3/4" diameter tube at lower tolerance level (95% / 95%) material j

properties is'0.75". Such an indication would have a bobbin voltage of > 40 volts.

1 i

The EPRI pulled tube data database demonstrates that no indication of < 10 volts has had a throughwall crack > 0.37". Therefore, it is unrealistic to assume that a 0.75" axial throughwall crack would develop in a plant where a

(

3.0 volt IPC is applied.

The crack length test variable, with > 0.6" long ODSCC specimens, is expected to bound by a factor of 1.5 the largest indications seen in the EPRI pulled tube data i

base for indications below 10 volts. In order to obtain indications with throughwall crack lengths >0.6", Comed used fatigue to lengthen certain laboratory induced ODSCC specimens.

.j Sensitivity to test temoerature:

Westinghouse has modified a test facility to accommodate high leak rates at operating temperature test conditions. The test facility has the capability to measure the leak rates up to at least 10 gpm at 615'F. Testing at elevated temperatures is extremely time consuming; therefore, to expedite testing the test.

plan included development of a temperature correlation factor. A correlation of operating and room temperature conditions was to be developed from test data obtained in this program. The existing leak rate adjustment procedures indicate that operating temperature leak rates are about a factor of 0.5 to 0.6 room temperature leak rates. This correlation was confirmed for indications confined within the TSP.

i 4

i i

j

m. :.-..

-.m.

)

I j

Sensitivity to crevice condition:

• If th' test program is expanded beyond the initial bounding test program described in e

Section III, some tests may be conducted with both " packed" TSP crevice conditions and " clean" TSP crevices. Crevice packing will be performed by packing the crevice with magnetite and a binder followed by baking of the specimen. This is typical of the deposits seen on pulled tubes. This test is representative of actual steam generator crevice conditions believed to be present at Byron and Braidwood. If the leak rates are considerably different, test results will be evaluated to determine appropriate application of the data in leakrate calculations. The initial bounding test program will be performed using unpacked crevices. This will provide a conservative leak rate value.

Sensitivity to TSP gap:

The range of possible maximum TSP clearances for drilled hole TSP steam generators is 0.025". The 0.025" value was obtained by applying a 95% confidence level to the upper diameter limit of a drilled support plate hole and the 95% confidence level of the minimum diameter of the tubing. This test at 0.025" clearance will provide a bounding leak rate value for maximum gap.

Sensitivity to crack exposure outside TSP:

The maximum TSP deflection with tube support plate stabilization is shown in WCAP-14273 to be 0.10" for model D-4 units with 3/4" tubing. This value is extremely conservative with a factor of 2 applied to the Tranflo loads. A review ofinspection data for Byron 1 and Braidwood I has not found any axial ODSCC indications extending beyond the edges of the TSP. Therefore, based upon a comparison of the real location ofindications within the tube support plates and a review of the i

conservatisms within the calculation of tube support plate maximum deflection, Comed's assessment is that testing with TSP offset of 0.10" for 3/4" tubing is extremely conservative. For 7/8" diameter tubing, offset values of 0.15" will be used to simulate the expected TSP maximum deflection value for Model 51 units.

Leakrate vs. Tube Pressurization:

Indications contained within the TSP will be pressurized and leak rates measured; at MSLB pressure between MSLB pressure and calculated burst above calculated burst pressure 1000 psi increments up to approximately 10,000 psi.

Testing may be repeated with crack offset of 0.1" and 0.15" outside TSP.

The objective of these pressurization steps is to determine the maximum leak rate vs crack opening configuration which is pestdated to occur.

Comparison of freespan to IRB leak rate:

Certain specimens will be pressurized to values below MSLB conditions while in freespan so that the freespan leak rate can be measured and extrapolated to MSLB conditions using the EPRI leak rate procedure. This value will then be compared to the IRB leak rate obtained from these specimens while they are confined within the TSP.

These data will be used to show a correlation between the freespan and IRB leak rate. The result may be that the freespan leak rate is higher than the IRB leak rate for certain size indications.

K :nle. htmi:St gen /IPCTesT; 3 0

w F

X X X X X X X X X X X X 5

1 6

E l

RU TA M a

X X X X X X X X X X X X m O a

O a

n R

=

is P

p iX 0

X X X X X X X X X X X X I

A 0

R T

0, T

L A

E 0

M D

1 TS

=

E T

P is C

A p

X X X X X X X X X X X X R

T 0

I L

5 TE E

6 M

D 2

A 5

R 7

A P

X X X X X X X X X X X 6

)BR r

O j

a T

v 6'.

S i

R a

s U

s 5 X X X X X X X X X X X B

E 4

s M

m O

R l

m F

E 54 L

D r

E c

X X X X X X X X X X X T

A 5

C a

2 I

c R

TSER D

E N

K O

C X X X X X X X X X X X X X X X A

I TA PN C

s I

E U

D i

su N

I T

. D A

E 1

1 o

K X X X X X X X X X X X X X X X t

1 E

r C L

u A P

B j

l A

T Y

T Y

E I

T R

Y is V

I U

D is p M

V T

U p

S TI A T

0 0

N I

R 0

S S

5 E

0 S

N E 6

C 0

P P P H" E

P T

S M

I T

T 2

1 P A A A 5

R E

E

=

= A G G G M4 '6 5 E

E T

T S

S E

E F

F P

P G E

7 G T S

F F

M F

L T

i M

I L

L L

L I

K5 5

- A M F

O O A A l

I M M C2 4

6 L O 5 F

A T

T R

O L M

". 2".

E 5

3 5

A O O 1

E A

0" 0 0 D D 0 1

n 1

2 2

c V R 6

P

a s

s F

X X X X X X X X X X X X u

e 5

1 6

E 7

l R

U TAa M X X X X X X X X X X X X m O a O T

R

=

is P

p X

0 X X X X X X X X X X X X I

A 0

R T

0, T

L A

E 0

M D

1 i

d

=

t i

P is C

A p

X X X X X X X X X X X X R

T 0

I L

5 TE E

6 M

D 2

A 5

R 7

A P

X X X X X X X X X X X 6

)BR T

l Y

I

(

HV 6

SR H

I S

U N 5 X X X X X X X X X X X B

E 4

M N

2 O

l G

I R

N F

E 5

4 L

D r

E c

X X X X X X X X X X X T

A 5

C a

2 ik c

i d

ER D

E N

K O

C X X X X X X X X X X X X X X X T

A I

A P

C N

I s

D l

t U

s N

u 1

I T

. D 2

A E

1 o K X X X X X X X X X X X X X X X t

1 C

EL s/ A B

7 P

A l

l T

Y T

Y E

T R

Y is p T-I T

I is V

I U

D V

I U

p s-T A

l T

0 0

N I

R 0

S S

5 C

6 0

M N

E I

T T

2 0

P P

P I

E P

D~5 S M 1

R E

E

=

P A A A G

T T

S S

= A G G G N3 6

5 E

E E

E F

F P P G E

7 G T S

F F

M F

L T

I M

I IL L

l L

A M F

O O A A L

l M M C'2 4

6 L

O 5 KS 5

T F

A T

R O

A

l. 2 E

L M

A O O E

5 3

5 R

1 P

O 0 0 D D 0 2

2 C

VR 6

1 t

Secti n III i

TEST PROGRAM 1

Test Plan Obiectivs Develop a bounding MSLB leak rate for large (>0.6") indications which have been restricted from burst (IRB) by the presence of the tube support plate (TSP). This bounding leak rate value will be used in a leak rate calculation which takes into account both freespan and IRB leakage.

Comed does not have an objective to create or test a low voltage (1 volt or less) 3/4" long crack. However, long cracks (>0.6") will be created and tested.

Total Test Program Based on Comed's evaluation of the critical variables required to meet the programs objective, a total test program was developed and is provided in Table III-1. The notes for Table III-1 outline the general testing sequence and prioritization criteria which determine the order in which specimens are tested. The specific testing parameters and specimen characteristics for completed tests are given in Section IV.

This test total program was developed to address sensitivity to:

Differences in leak rates between 3/4" and 7/8" diameter tubing l

Sensitivity of crack length inside the support Differences in leak rate data between room temperature and operating condition tests (validate roon temperature to operating condition correlation)

Differences between leak rates in packed versus clean crevices Differences in TSP crevice clearances Length of crack extending outside the TSP Differences in pressurization levels Differences between freespan and IRB leak rates Bounding Test Plan Using Table III-1, the bounding test program is defined as tests 1-1,1-2,1-6,1-7, 2-1,2-4,2-7,2-10 and 4-1. This testing will provide a conservative bounding leak rate l

value for IRBs at MSLB. Testing of these nine specimens is scheduled for completion by July 15,1995.

It is Comed's position that the only testing required to bound the MSLB leak rate are tests 2-1,2-4,2-7 and 1-7. Other tests are only planned to improve the industries understanding ofleakage from IRB's.

1 E : nla : Pytwd. St gen / IPC'esT 11 I

m TABLE III-1 Test Matrix for Indications Restricted from Burst (IRBs)

Crevice Crack Length Gap Free Crack to TSP Bladder Test Test Pri-Tube Temp Span Offset Pres.

Test No.

Seq.

ority Dia.

Leak AP" Time Open Pack

.25-

.45.6

.6-

.02

.025 Test 0.0" 9.1"

.15" Offset Days

.45

.75 (inch) 1-1 la 1

7/8 615' x

x x

x x

x 0.0 12 1-2 la 1

7/8 615' x

x x

x x

x 0.15 12 1-3 la 2

7/8 615*

x x

x x

x x

0.15 12 1-4 lb 4

7/8 615' x

x x

x x

7 1-5 lb 5

7/8 615' x

x x

x x

12 1-6 la 1

3/4 615*

x x

x x

x x

0.0 12 1-7 la 1

3/4 615' x

x x

x x

x 0.1 12 1-8 la 2

3/4 615' x

x x

x x

x 0.1 12 1-9 lb 4

3/4 615' x

x x

x x

7 1-10 lb 5

3/4 615' x

x x

x x

12 1-11 la 3

7/8 615' x

x x

x x

x 0.15 12 1-12 la 3

3/4 615' x

x x

x x

x 0.1 12 2-1 2

1 7/8 615' x

x x

x x

x 0.15 12 2-2 2

2 7/8 615' x

x x

x x

x 0.15

'12 2-3 2

3 7/8 615' x

x x

x x

x 0.15 12 2-4 2

1

-7/8 615' x

x x

x x

x 0.15 12 2-5 2

2 7/8 615' x

x x

x x

x 0.15 12

~.

TABLE III-1 Crevice Crack Length Gap Free Crack to TSP Bladder Test Test Pri-Tube Temp Span Offset Pres.

Test No.

Seq.

ority Dia.

Leak AP" Time Open Pack

.25

.45.6

.6-

.02

.025 Test 0.0" 0.1"

.15" Offset Days

.45

.75 (inch) 2-6 2

3 7/8 615' x

x x

x x

x 0.15 12 2-7 2

1 3/4 RT,T x

x x

x x

x 0.1 12 2-8 2

2 3/4 615' x

x x

x x

x 0.1 12 29 2

3 3/4 615' x

x x

x x

x 0.1 12 2-10 2

1 3/4 RT,T x

x x

x x

x 0.1 12 2-11 2

2 3/4 615' x

x x

x x

x 0.1 12 2-12 2

3 3/4 615' x

x x

x x

x 0.1 12 3-1 3

3 7/8 T,RT x

x x

x x

0.15 10 3-2 3

3 7/8 T,RT x

x x

x x

0.15 10 3-3 3

4 7/8 T RT x

x x

x x

0.15 10 4-1 4

1 7/8 RT x

x x

x x

0.15 10 4-2 4

2 3/4 RT x

x x

x x

0.1 10 Notes:

1. Test sequence includes pmssurizing with a bladder typically to above the free span burst pressure. Some specimens include incremental increases in bladder pressure beyond that equivalent to a free span burst. For test sequences 1 and 2, the bladder pressurization and subsequent leair tests follow leak tests that apply primary side pmssure and flow to obtain the APs. Thus, for these tests, the bladder pressurization is performed to open the crack beyond that obtained within the pressure capability of the facility.

=

NOTES FOR TABLE III-1 Test Plan for IRBs.

Test Sequences Test Sequence 1: 615*F, Crack Lengths > 0.6" Sequence la A. Free span leak test at 1500,1700 and 2000 psi AP B. Leak test with crack centered (0.0 offset) in TSP at 2000,2335 and 2560 psi AP C. Measure crack opening diameter and area D. Leak test with crack 0.1" offset outside TSP at 2560,2700,2900 psi AP (up to facility limit)

E. Measure crack opening diameter, area and evaluate crack extension F. With crack centered or 0.1" (test matrix specification) offset outside TSP, pressurize to above calculated burst pressure with bladder

• Note: Test sequence 1 is applied to the longest cracks which are expected to open up and contact the ID of the TSP hole within the pressure / flow limits of the facility. The bladder pressurization step is applied to assure crack flank to TSP contact for comparisons with the leak rates from step D.

G. Leak test with crack centered or 0.1" offset outside TSP at 2335 and 2560 psi AP H. Measure crack opening diameter, area and evaluate crack extension I.. With the same crack position as step F, pressurize with a bladder (with foil if necessary) to about 1000 psi above the prior pressurization step J. Repeat leak test of step G K. Repeat steps I and J with increases in bladder pressure in 1000 psi increments until bladder / foil pressurization increase cannot be achieved (approximately burst pressure inside TSP on order of 8000 psi)

• Note: Ifit is demonstrated on one sample in this test sequence, that the leak rates do not significantly increase by the pressurizations of steps I to K, steps I l

to K may not be repeated on additional specimens and this test sequence will j

be terminated at step H for the later specimens i

L. Measure crack opening diameter, area and evaluate crack extension l

Sequence Ib Perform test with Sequence la steps A to E (i.e., no bladder pressurization steps) 1

NOTES FOR TABLE III-1 Test Sequence 2: 615'F and Room Temperature, Crack Lengths < 0.6" A. Free span leak test at 1500,1700 and 2000 psi AP B.: Leak test with crack tip centered at 2000,2335,2560 psi AP up to facility limit C. Leak test with crack tip 0.1" offset from the edge of the TSP at 2560,2700 psi l

AP up to facility limit D. Measure crack opening diameter, area and evaluate crack extension E. With crack tip 0.1" offset, pressurize to above calculated burst with bladder i

• Note: Test sequence 2 is applied for shorter cracks which may not open to significantly contact the ID of the TSP hole within the pressure / flow limits of the facility. Thus, steps A and B may result in comparable leak rates. The bladder pressurization step is applied to assure that crack flank to TSP contact is achieved to assess the influence on leak rates.

F. Leak test at 2335,2560 psi AP at both room and operating temperature for at least one specimen.

.G. Measure crack opening diameter, area and evaluate crack extension H. With the 0.1" crack position, pressurize with a bladder (and foil if necessary) to about 1000 psi above the prior pressurization step I. Repeat leak test of step F J. Repeat steps H and I with increases in bladder pressure of 1000 psi increments until bladder / foil pressurization increase cannot be achieved (approximately burst pressure inside TSP on order of 8000 psi)

• Note: Ifit is demonstrated on one sample in this test sequence or by the equivalent pressurizations of Sequence la tests, that the leak rates do not significantly increase by the pressurizations of steps H to J, steps H to J may not be repeated on additional specimens and this test sequence will be tenninated at step G for the later specimens K. Measure crack opening diameter, area and evaluate crack extension Test Sequence 3: 615'F and Room Temperature Leak Rate Comparisons l

A. Pressurize to above calculated burst pressure with bladder l

B. Room temperature test at 2000,2335,2560 psi AP C. Operating temperature test at same pressure differentials D. Measure crack opening diameter, area and evaluate crack extension E. Move crack to 0.1" outside TSP, pressurize to same pressure with bladder F. Room temperature test at same pressure differentials G. Operating temperature test at same pressure differentials H. Measure crack opening diameter, area and evaluate crack extension l

k nia.bybwd teMant395 wpf 3

l i

NOTES FOR TABLE III-1 Test Sequence 4:

Room Temperature, Bladder Pressurization to j

Establish IRB Leak Rate Magnitude and Effects of High " Burst" Pressures on Leak Rates i

A. Pressurize to above calculated burst pressure with bladder B. Room temperature test at 2335,2560 psi AP C. Measure crack opening diameter, area and evaluate crack extension D. Move crack to 0.1" outside TSP and pressurize to the same pressure E. Room temperature repeat of step B leak rate tests F. Measure crack opening diameter and area G. With the 0.1" crack position, pressurize with a bladder (and foil if necessary) to about 1000 psi above the prior pressurization step H. Repeat leak test of step B I. Repeat steps F and G with increases in bladder pressure of 1000 psi increments until bladder / foil pressurization increase cannot be achieved (approximately burst pressure inside TSP on order of 8000 psi)

+ Note: Ifit is demonstrated on one sample in this test sequence or by the equivalent pressurizations of Sequences la or 2 tests, that the leak rates do not significantly increase by the pressurizations of steps G to I, steps G to I may not be repeated.

J. Measure crack opening diameter, area and evaluate crack extension Packed Crevice Simulation

• Pack crevice with magnetite and a binder followed by baking of the specimen to obtain a fairly hard deposit typical of that found on pulled tubes at TSP crevices t

k nla bybod telrtamm 395 wg4

NOTES FOR TABLE III-1 Test Plan for IRBs Test Priorities Priority 1 (Bounding Test Program)

Recommended test matrix to establish bounding leak rate for large cracks (test sequence 1) and the leak rate dependence for more realistic crack lengths (test sequence 2)

• - An initial test (sequence 4) of an indication pressurized by a bladder to obtain an early estimate of the magnitude ofleak rates to be expected Priority 2 Repeat of priority 1 tests. Tests performed upon completion of priority 1 tests only if bad test data are obtained or the initial test results in unacceptable uncertainties on the leak rates relative to adequately defining a leak rate model for IRBs Priority 3 Tests performed to compare room temperature leak rates with operating temperature leak rates. These tests would be performed only if the leak rates of priority 1 tests exceed the facility capability at operating temperatures and some of the priority 1 tests must be run at room temperature.

Tests with packed crevices. Tests to be performed ifin situ leak rates are to be used for reference SLB leak rates rather than free span plus IRB leak rates.

These tests would provide physical insight into expectations to be obtained with in situ leak rate measurements.

Priority 4 Tests of additional variables not considered to be necessary to adequately define IRB leak rates.

Priority 5 Test variables that are judged not worthy of considertion for testing k.nla trvbwd tstrtanm 396 wpf 6

Secti::n IV Bounding Test Program Results Table IV-1 lists the nine specimens defined as the bounding test program. The last column of the table gives the test status to date.

The following Section gives the available test results. A test status is given, followed by summary of results, overall conclusions, general test information, test sequence and testing results. Testing is underway on test numbers 1-1,1-2 and 2-1, the test sequence and available specimen information for these tests is given for clarification.

The significant tests to determine a bounding leak rate value for 3/4" tubing with a 0.10" TSP offset have been completed and are discussed in the attached pages. The remaining portions of the " bounding" test program are scheduled to be complete and results available by July 15,1995.

Bounding Test Program Differences Since 4/3/95 Submittal In order to facilitate testing and apply lessons learned during the early phases of the test program, minor changes were made to the test program as submitted to the -

NRC on April 3,1995 reference 6. These changes do not significantly effect the test results or conclusions.

The following is a detailed listing of differences between the test program submitted in reference 6 on April 3,1995 and the actual testing that either has been or will be conducted. The corresponding notes to describe numbered changes follow the i

specimen listed below.

Test 1-1

• ODSCC throughwall crack length of 0.62" was obtained by lengthening an existing ODSCC specimen with fatigue.

NOTES: 1, 2, 3, 4, 5 Test 1-2 l

• ODSCC throughwall crack length of 0.62" was obtained by lengthening an existing ODSCC specimen with fatigue.

NOTES: 1, 2, 3, 4, 5 Test 1-6 1

• Test plan calls for a 0.025" TSP gap, test was inadvertantly run with a 0.028" gap.

This adds an unecessary conservatism to the test results.

NOTES: 2, 3, 4, 5 k:nla:Dykswd:Stgen/IPC1*sT12

Test 1-7 ODSCC throughwall crack length of 0.60" was obtained by lengthening an existing j

ODSCC specimen with fatigue.

Freespan leak rate testing was not performed on this specimen. Testing was not i

performed due to an oversite at the test facility. Upon discovery testing had already been completed beyond bladder pressurization, making freespan testing at that point of no value.

The freespan tests were originally planned to aid identification of crack interaction with the TSP based on differences between freespan and with TSP leak rates.

However, freespan testing might plastically open the crack face more than the tube to TSP gap and then require deformation of the crack face to perform offset leak tests. It was then decided to perform a freespan leak test after the offset only as a demonstration of the magnatude change in leak rates and without the the presence of the TSP.

Test 1-7 freespan data is not a significant loss of data since TSP interaction above about 2200 psi is apparent in the slope of the leak rate verses AP curve. The free span data point for Test 1-6 adaquately demonstrates the large difference in leak rate between freespan and within the TSP for large cracks.

NOTES: 2, 3, 5 Test 2_-1 ODSCC throughwall crack length of 0.515" was obtained by lengthening an existing ODSCC specimen with fatigue.

NOTES: 1, 2, 3, 5, 6 i

Test 2-4

)

• Testing originally called for crack to be centered in TSP. After initial flow testing was completed, and prior to bladder pressurization, program was revised to call for the crack tip to be placed at the edge of the TSP prior to leak rate testing. This provides a more conservative leak rate value. The results for this test show leakage i

is essentially freespan with or without the TSP and thus the change in crack alignment had no influence on the Test 2-4 results.

This change is consistent with the May 25,1995 clarification letter reference 7, and the leak rate test program.

NOTES: 1, 3, 5, 6, 7 Test 2-7

• ODSCC throughwall crack length of 0.577" was obtained by lengthening an existing ODSCC specimen with fatigue.

F : nla : pytwl: st gen / IPctesT:13

l

• Testing originally called for freespan and 0.0" offset to be conducted at operating temperature conditions. " Low pressure" testing was performed for these test steps at room temperature up to 2335 AP. This was to expedite testing program.by 4 to 6 1

days. This does not limit the applicabilty of the test results since the most limiting 0.10" offset condition was tested hot, and the cold to hot adjustment procedure is -

well supported by the test results.'

]

i This change is as describes in the May 25,1995 test program reference 7.

I NOTES: 2, 3, 5, 6 o

Test 2 !

NOTES: 2, 3, 5, 6, 7 Test 4-1

• Added operating temperature test condition leak rate test after bladder

-f pressurization up to 8900 psi. This provides additional data to strengthen temperature correlation.

I

.i 4

f i

h i

6 i

t f

I

,,,a. ;.~.

.n.m., a.

'l

NOTES FOR DESCRIPTION OF CHANGES

1. Testing for 7/8" diameter tubing was conducted with a 0.15" TSP offset rather than the originally specified value of 0.10". This is the maximum calculated TSP displacement value with the anticipated tube expansion, for a Model 51 steam generator which has 7/8" diameter tubing.

2. Testing originally called for crack to be centered in TSP. Program was revised to call for the crack tip to be placed at the edge of the TSP prior to leak rate testing.

This provides a more conservative leak rate value.

3. Testing originally called for TSP to be offset 0.10", it was not specifically stated that the crack should extend 0.10" (or 0.15" for 7/8" tubing) outside TSP. Program -

was revised to state that the crack tip should extend 0.10" (0.15") outside TSP.

4. Original test sequence called for free span leak rate up to 2000 psid to be conducted prior to 0.0" offset testing. Test sequence was changed to require freespan leak rates after 0.0" and 0.10" (0.15" for 7/8" tubing) offset at the highest pressure achieved. This allows freespan leak rates to be conducted at pressures higher than the original 2000 psid without concern of opening the crack face beyond the TSP gap for later testing within the TSP.

5. Original test program called for 0.0" offset at pressures up to 2560 psid followed by 0.10" offset starting at 2560 psid. Program was changed to perform 0.0" offset testing up to 2335 psid followed by 0.10" (0.15" for 7/8" tubing) offset starting at 2335 psid. This change was made to obtain more leak rate data for the limiting 0.10" offset conditions.

6. Original test sequence called for freespan leak rate up to 2000 psid to be conducted prior to 0.0" offset testing. Test sequence was changed to require freespan testing after the 0.0" offset and before the 0.10" offset. This change for moderate length cracks was made to permit easier comparison of freespan and offset 0.10" leak rates (more limiting than 0.0" offset) to aid assessment of potential interaction with the TSP. In addition, the start of 0.10" offset testing was lowered from 2560 psid to 2335 psid to obtain more leak rate data for the limiting 0.10" offset condition.

7. Original test program called for initial bladder pressurization above calculated burst, step was added to pressurize approximately 1000 psi below calculated burst. This provides another data point to determine where max leak rate occurs.

E ! ale.Dytet :St gen /IPChsT:17

TEST PROGRAM (LATEST FINAL) CONCLUSIONS Tect 1-6 Test 1-6 provides a conservative upper bound of 4.7 gpm for IRB at the maximum potential TSP offset for 3/4" tubing of 0.10". The test specimens throughwall crack length of 0.74" is essentially equal to the thickness of the TSP. ODSCC at Byron and Braidwood has been shown to stay contained within the TSP by both eddy current analysis and tube pull results. Throughwall crack lengths of 0.74" are expected to have eddy current indications in the >40 volts range. The Byron and Braidwood Unit I largest indications seen to date had voltages of 10.3 and 10.9 volts, with throughwall crack lengths of 0.20" and 0.27" respectively. Therefore, it is not likely that a cracklength of 0.74" could ever develop in a plant where 3 volt IPC is applied. In addition, for this specimen it was shown that TSP constraint reduced the maximum SLB leak rate by more than a factor of three compared to freespan, and that TSP interaction occurred at 1950 psid.

Throughwall Crack Lengths > About 0.5"- Tests 1-6,1-7,2-7 (3/4")

Indications with throughwall crack lengths greater than approximately 0.5" result (n crack faces opening to interact with TSP prior to reaching SLB conditions of 2335 to 2560 psi AP and result in leak rates less than free span indications.

SLB leak rates resulting from flow pressurization to AP su are approximately 3.0, 3.2 and 4.7 gpm for initial start of test throughwall crack lengths of 0.577",0.60" and 0.74", respectively.

Throughwall Crack Lengths <About 0.5"- Tests 2-4 (7/8"),2-10 (3/4")

Indications with throughwall crack lengths less than approximately 0.5" have leak rates typical of free span indications and show no significant interacthe with the TSP

• SLB leak rates resulting from flow pressurization to AP su are approximately 0.47 and 1.2 gpm for initial throughwall crack lengths of 0.29" and 0.425",

respectively.

Effects of Bladder Pressurization on Leak Rates SLB leak rates following bladder pressurization at the TSP offset condition are not significantly different from leak rates obtained by flow pressurization to 2560 psi for throughwall crack lengths > approximately 0.5 inch which result in interaction with TSP prior to reaching SLB conditions.

For crack lengths < 0.5", which do not interact with the TSP prior to reaching SLB conditions, bladder pressurization to the free span burst pressure increase the leak rates above that obtained by flow pressurization but the leak rates remain less than those obtained with > 0.5" crack lengths.

Bladder pressurization above the free span burst p wsure result in predictable increases indicative of controlled crack openings.

E:nla:pfhed stgen/IPcTest:15

IRB Leak Rate Impact with 3.0 Volt IPC The maximum leak rate value for an IRB in a 3/4" tube is conservatively bounded by 4.7 gpm (obtained by flow pressurization at 2560 psi and 0.10" TSP offset). The conservatisms in this value are:

The largest leak rate of 4.7 gpm obtained in the tests completed Gncluding all 3/4" diameter tubing tests) was found for an upper bound 0.74" throughwall crack (larger than would be expected to develop with a 3 volt IPC) under flow pressurization to AP w = 2560 psi.

s No credit was taken for the TSP crevice being packed and reducing the leak rate.

The crevices at both Byron and Braidwood are believed to be packed.

The maximum throughwall crack length tested (0.74"), is the maximum crack length that could develop in a 0.75" thick TSP.

The largest indications seen at Byron and Braidwood had voltages of 10.3 and 10.9 volts, with throughwall crack lengths of 0.20" and 0.27," respectively. Crack lengths of 0.74" are expected to produce indications > 40 volts, which are not likely to develop in a plant where 3 volt IPC is applied.

Testing was performed using a minimum TSP gap of 0.025". This bounds the 95% confidence level for gap sizes.

TSP deflection values of 0.10" for 3/4" diameter tubing and 0.15" for 7/8" diameter tubing are double that expected to be seen due to a conservative factor of two being applied to TRANFLO loads.

Indications > approximately 0.5" throughwall interact with the TSP prior to reaching AP su and show no significant increases in leakage above the TSP offset leak rate at AP su even after bladder pressurization to the free burst pressure at the offset condition.

For throughwall indications < approximately 0.5", which can be expected to bound indications at Braidwood-1 and Byron-1 following implementation of a 3.0 volt repair limit, the crack openings do not interact with the TSP and the resulting leak rates are typical of free span leak rates.

The locking of TSPs through tube expansion actually reduces the amount of leakage possible through large (>0.5") indications as compared to freespan leak rates. This coupled with the effect of eliminating the possibility of tube burst, actually makes the application of a 3 volt IPC with tube expansion more conservative than a 1 volt IPC without tube expansion.

i K : nla : Ilyta.d. St pen / I P(Test i l 6

TEST 1-1 TEST RESULTS ARE NOT YET AVAILABLE K :nla :Pyt=d :St gen /IPCTesT:15

Table IV-1 Test Matrix for Indications Restricted from Burst (IRBsh Status - June 20,1995 Throughwall Crack Length Free Crack to TSP Offset Bladder Test Tube Specimen Temp.

Span Press.

Test No.

Dia.

Type,

'F Leak AP*

Status No.

.25.43

.45.60

.60.75 Test 0.(Y' O.10" 0.15" Offset (inch) 1-1 7/8 CorrSat.

615' O.62" x

x x

0.15 Offset tests after bladder 8161G pmssurization requimd 1-2 7/8 CorrEat.

615*

n.62" x

x x

0.15 8161E 1-6 3/4 Corrosion 615' O.76" x

x x

0.10 Needs final R.T. offset test 2008E 1-7 3/4 CorrSat.

615' O.60" x

x x

0.10 Needs final R.T. offset test 2051A 2-1 7/8 CorrEat.

615' O.515" x

x x

0.15 Initial freespan and 8161A centered tests complete 2-4 7/8 Corrosion 615',

x x

x 0.15 Complete 4C218 R.T.

0.29" afler Press.

2-7 3/4

- CorrSat.

R.T.,

x x

x 0.10 Needs final R.T. offset test 2051E 615' O.577" after P mss.

2-10 3/4 Corrosion 615' O.425" x

x x

0.10 Needs fmal R.T. offset test 2051B 4-1 7/8 Corrosion R.T.

0.24" 0.50" x

x 0.15 Complete - up to 8900 psi 4B214 (UT) bladder press.

Note 1. Test sequences include pmssurizing with a bladder typically to the fme span burst pressure. Test 4-1 includes incremental increases in bladder pressum beyond that equivalent to a free span burst. Tests 2-4 and 2-10 include bladder pressurizations below and at the fme span burst pressure. Bladder pmss. is performed to open the crack beyond that obtained within the pressure capability of the facility.

e apetegetbrideak? wp5 June 20.1995

- ~. -.

-_._-__m_,_

Test Plan for (IRBs)

Test 1-1 General Test Information e Utilize large leak test facility testing e Test 7/8" diameter, corrosion plus fatigue specimen 8161G:

Silastic mold dye penetrant - 0.62" OD with 0.62" ID e leak test at 615'F except as noted. Testing at > 615'F is acceptable.

o Locate specimen relative to the TSP per requirements for crack locations within TSP and offset fmm TSP e Tubes shall be free to move within TSP during pressurization or, as a minimum, the tube shall contact the TSP hole at 180* fmm the crack being leak tested.

Test Sequence A. Hot (615'F) leak test with crack inside the TSP and crack tip at edge of TSP at 1900 and 2050 and 2335 psi AP B. Measure crack opening length, diameter, area (total lengths and thmwall lengths / width) and evaluate crack tearing extension (beyond cormsion crack length).

C. Hot (615'F) leak test with crack tip 0.15" offset outside TSP at 2335, 2560,2700,2800 psi AP up to facility limit D. Measure crack opening length, diameter, area (total lengths and thmwall lengths / width) and evaluate crack tearing extension (beyond corrosion crack length).

E. Perform hot (615'F) free span leak test at the highest AP reached in the Step C test. Cam must be excercised in performing this test such that higher APs are not applied to the specimen due to the potential for significant tearing of the crack. Although the test results would not be valid, stan testing at a AP about 100 psi lower than the highest AP from Step C and terminate testing if the measured leak rate is about a factor of 3 (factor of 5 for a cold test) or more higher than the largest leak mte obtained from Step C.

F. Measure crack opening length, diameter, area (total lengths and thmwall lengths / width) and evaluate crack tearing extension (beyond corrosion crack length).

G. With the crack tip 0.15" offset outside the TSP, pressurize to 4150 psid with a bladder. If following pressurization, the cormsion crack tip is more than 0.15" outside the TSP, adjust the specimen to obtain 0.15" of the corrosion crack outside the TSP prior to the leak testing of Step G.

Measure the total crack length, the through wall length / width, the exposed throughwall length / width and the tube diameter across the crack flanks including at least 5 points along the crack plus the locations of the edges of the TSP with the crack tip 0.15" offset and at the edge of the TSP.

e Report whether the tube is tight or loose in TSP following pressurization.

H. Hot (615'F) leak test with crack inside the TSP and crack tip at the edge of the TSP at 2335 and j

2560 psi AP I. Hot (615'F) leak test with crack tip 0.15" offset outside TSP at 2335 and 2560 psi AP J.

R.T. leak test with crack tip 0.15" offset outside TSP at 2335 and 2560 psi AP K. Measure corrosion throughwall length and length versus depth profile.

s e upwp.i%hepec.MJurr 3D,19M

e TEST 1-2 TEST RESULTS ARE NOT YET AVAILABLE 1

1 v

E nla Bybwd:Stgen/IPCTest:36

Test Plan for (IRBs)

Test 1-2 General Test Information e Utilize large leak test facility testing e Test 7/8" diameter, specimen 8161-E: Silastic mold dye penetrant - 0.64" OD with 0.62" ID e leak test at 615*F except as noted. Testing at > 615*F is acceptable.

e Locate specimen relative to the TSP per requirements for crack locations within TSP and offset from TSP e Tubes shall be free to move within TSP during pressurization or, as a minimum, the tube shall contact the TSP hole at 180* from the crack being leak tested.

Test Sequence A. Hot (615*F) leak test with crack inside the TSP and crack tip at edge of TSP at 1900 and 2050 and 2335 psi AP B. Measure crack opening length, diameter, area (total lengths and thruwall lengths / width) and evaluate crack tearing extension (beyond corrosion crack length).

C. Hot (615'F) leak test with crack tip 0.15" offset outside TSP at 2335,2560,2700,2800 psi AP up to facility limit D. Measure crack opening length, diameter, ama (total lengths and thmwall lengths / width) and evaluate crack tearing extension (beyond corrosion crack length).

E. Perfonn hot (615*F) free span leak test at the highest AP reached in the Step C test. Care must be excercised in performing this test such that higher APs are not applied to the specimen due to the i

potential for significant tearing of the crack. Although the test results would not be valid, start testing at a AP about 100 psi lower than the highest AP from Step C and terminate testing if the measured leak rate is about a factor of 3 (factor of 5 for a cold test) or more higher than the largest leak rate obtained fmm Step C.

j F. Measure crack opening length, diameter, area (total lengths and thruwall lengths / width) and evaluate crack tearing extension (beyond cormsion crack length).

G. With the crack tip 0.15" offset outside the TSP, pressurize to 4,080 psid with a bladder. If following pressurization, the corrosion crack tip is more than 0.15" outside the TSP, adjust the specimen to obtain 0.15" of the corrosion crack outside the TSP prior to the leak testing of Step G.

Measure the total crack length, the through wall length / width, the exposed throughwall length / width and the tube diameter across the crack flanks including at least 5 points along the crack plus the locations of the edges of the TSP with the crack tip 0.15" offset and at the edge of the TSP.

e Report whether the tube is tight or loose in TSP following pressurization.

H. Hot (615*F) leak test with crack inside the TSP and crack tip at the edge of the TSP at 2335 and 2560 psi AP I.

Hot (615'F) leak test with crack tip 0.15" offset outside TSP at 2335 and 2560 psi AP J.

R.T. leak test with crack tip 0.15" offset outside TSP at 2335 and 2560 psi AP K. Measure corrosion throughwall length and length versus depth pmfile.

. #,.%m x %

e-g TEST 1-6 1

l J

i l

l s

I E :naa ;htwd:St gen / 2 PCTesT:17

=

e Tcct 1-G: Summ:ry cf Tcat R::ults Status - June 15,1995 Test Status

• Specimen with 0.74" TW crack by dye penetrant at start of test

• Test was performed with a 0.028" gap as the TSP simulant had been sized to a larger tube diameter than the 0.745" diameter of this specimen

• Hot leak testing completc

• Room temperature leak tests following bladder pressurization not complete Summary of Test Results

• Shallow slope ofleak rate versus AP curve above about 1900 psi indicates interaction with TSP and reduced leak rates

- All slopes ofleak rate curve are less than typical of free span slope

- Larger slope and leak rate for CRACKFLO free span predictions supports TSP interaction

- Pressurization to 2276 psi with the crack within the TSP opened the plastic crack width to a maximum of 0.024"

• Leak rates at SLB pressure differential with 0.10" offset are bounded by about 4.7 gpm prior to and after bladder pressurization

- This test, performed with a 0.028" gap, resulted in the widest crack openings of all tests performed (except subsequent bladder pressurization for this specimen) with maximum crack opening widths of 0.044" inside the TSP and 0.026" outside the TSP

- The crack opening visible by light through the crack was 0.724" of the total 0.750" crack length and was more than 0.019" wide for > 0.6" length

- Plastic deformation increased the crack opening diameter to the ID of the tube over about 0.2" at the center of the crack

• Leak rates for crack within the TSP following bladder pressurization at 0.10" offset to the free span burst pressure of about 3220 psi are approximately equal to that obtained for 0.10" offset prior to bladder pressurization.

- The bladder pressurization had no significant influence on the leak rate even though the maximum plastic width increased from 0.044" to 0.050". However, the increased bladder pressurization did not significantly open the crack width at the ends of the crack

• It is not clear whether the increase in leak rate at about 2270 psi for the crack within the TSP is an error in the measurement or due to additional crack opening within the' TSP. The measurable crack opening did not extend outside the TSP during this test

• The measured freespan leak rate of 13.1 gpm (facility limit) at a AP of 1495 psi following prior testing at 2530 psi is substantially higher than the 4.7 gpm obtained for the crack constrained by the TSP even though the pressure differential is much lower

- The measured leak rate at 1495 psi is high due to hysterisis effects. CRACKFLO would predict a free span leak rate of about 17 gpm at SLB conditions for a 0.70" throughwall crack.

e apr\\epn\\iridesk2 wp5 June 17,1995

_ _ _ _ _ ~ _ _

l t

~

Test 1-6: Sununary of Test Results Status - June 15,1995 i

Overall Conclusions e This test of a 0.74" throughwall crack mpresents an upper bound leak test since throughwall f

. lengths of this magnitude would not be expected.

j Cracks are not expected to grow larger than the thickness of the TSP (0.75")

Cracks of this length would be in the > 40 volt range, themfore they are not likely to develop in a plant applying 3.0 volt IPC

- A 0.74" TW length is larger than would ever be expected in field service even for a mpair limit l

of about 15 volts as shown by European experience

.'e The SLB leak rate prior to and after bladder pmssurization is bounded by about 4.7 gpm including the maximum potential 0.10" TSP offset condition

- e TSP constraint reduces the maximum SLB leak rate by more than a factor of thme compamd to

{

free span conditions -

j e.For this 0.74" TW indication prior to leak testing, the leakage results indicate the TSP interaction l

occured at 1950 psi AP or lower j

t i

l i

4 4

e s:epcWtnank.2 wp5 Jew 19,1W$

m_

I 1

Test Plan for (IRBs)

Test 1-6 General Test Information e Utilize large leak test facility testing e Test 3/4" diameter, specimen 2008E

- Corrosion (no fatigue) crack length: Silastic mold dye penetant - 0.735" OD with 0.76" ID e Ixak test at 615*F except as noted. Testing at > 615*F is acceptable.

e Locate specimen mlative to the TSP per requirements for crack locations within TSP and offset from TSP

• Tubes shall be free to move within TSP during pressurization or, as a minimum, the tube shall contact the TSP hole at 180* from the crack being leak tested.

Test Sequence A. Hot (615'F) leak test with crack inside the TSP and crack tip at edge of TSP at 1900 and 2050 and 2335 psi AP B. Measure crack opening length, diameter, area (total lengths and thmwall lengths / width) and evaluate crack tearing extension (beyond corrosion crack length).

C. Hot (615'F) leak test with crack tip 0.10" offset outside TSP at 2335,2560,2700,2800 psi AP up to facility limit D. Measure crack opening length, diameter, area (total lengths and thmwall lengths / width) and evaluate crack tearing extension (beyond corrosion crack length).

E. Perform hot (615*F) free span leak test. Care must be excercised in performing this test such that higher APs are not applied to the specimen due to the potential for significant tearing of the crack.

Although the test results would not be valid, start testing at a AP lower than the highest AP from Step C and terminate testing if the measured leak rate is about a factor of 3 or more higher than the largest leak rate obtained from Step C.

F. Measum crack opening length, diameter, area (total lengths and thmwall lengths / width) and evaluate crack tearing extension (beyond corrosion crack length).

G. With the emek tip 0.10" offset outside the TSP, pressurize to 3200 psid with a bladder. If following pressurization, the corrosion crack tip is more than 0.10" outside the TSP, adjust the specimen to obtain 0.10" of the corrosion crack outside the TSP prior to the leak testing of Step H.

Measure the total emck length, the through wall length / width, the exposed throughwall length / width and the tube diameter across the crack flanks including at least 5 points along the crack plus the locations of the edges of the TSP with the crack tip 0.10" offset and at the edge of the TSP.

e Report whether the tube is tight or loose in TSP following pressurization.

H. Hot (615'F) leak test with crack inside the TSP and crack tip at tne edge of the TSP at 2335 and 2560 psi AP I.

Hot (615*F) leak test with c ack tip 0.10" offset outside TSP at 2335 and 2560 psi AP J. R.T. leak test with crack tip 0.10" offset outside TSP at 2335 and 2560 psi AP K. Measure corrosion throughwall length and length versus depth profile.

S NPE' MMM M M kl

e Test 1-6 Indications Restricted From Burst Leak Rate Tests (as-measured, without adjustment to reference conditions) um sn>

~

s---.--+

w--ee.m

-+

h,

~~~- ~ - - - - ' -

i,

_._.,_m..._..

.. _. _..,.. ~.. _.

Test Sequence E

CL

+ Offset 0.10 HT O

A g

& Freespan, HT g 10 (Mi

• O + Centered.HT.3220 E

• 0

• Offset 0.10,HT,3220 g.-.=* p.9...

- _ - _ _ c**c

'*c' I

l.lNI 1810 IMID lR(K) 20f10 2NN) 2410 2NMI Ap (psi)

Test 1-6 Indications Restricted From Burst Leak Rate Tests (Normalized to Tp=615*F and ps=15 psia Conditions) 10lLO

-4

_7

~ Netp%C W h 3BNpgQp M jeg;f:

1

~-^'t--~~T--- ~ ~~ 7 ~~~-

1

'"~

teekadeseIseIDjiestueelsWestiJh>0 n)

"- ~~l [~ T[ "- ~[~...

mensmusineuemem-m +;

~i'

~

i i

h6gaggg+M.

1 3

7 mm m

h..

9.

4 i

.-L_

._..._L....

._,...4._-

j

[

O Centered.HT f

^

l I

f i

j

+ 0ffset 010. HT 4

(

r

- - pred.cied. e.7 creen

"")'

j

. g 7 ;

& Freespan, HT 7 ggq ;.._._ p _

._._.f._._.;__._...r._4._

-..._._p

. o centered. HT.32co 4

-.....j. _

L._ _ 4 _ ___

. o..o,, set o to HT. 3220

.r__

}.

f.,, -

=J

-f 4

4 j-q I

y].y.-y0...

j

. o..o - c ' _'

o i

s l

.. _ d -

.._..z.d i

10 14m tHm INO thm lNNI lWW 21HNI 2lmi 22tm 2KU 24N1 2MNi 2ND 2700 2WM Ap (psi) l

Test 16. Summary cf Test Results Specimen 2008E, Tube Dia. = 0.745", Gap = 0.025" Bladder Tube Total Total Tota!

Exposed Exposed Max.

Min.

Leak Rate Test Results Pressure Offset Angle Crack TW TW TW TW Dia.

Dia.

(psi)

(in.)

Length Length Area Length Area (in.)

(in.)

(in.)

(Max.

(in')

Max.

(in')

Note 1 AP Rate Temp.

Width)

Width)

(p8i)

(Epm)

(*F) 1 (in.)

(in.)

None 0.0 0*

0.735 0.760'8' N.Ay2>

0.0 N.A.

O.745 N.Ay23 1837'5' 1.69 630*F Steps O D

A&B 180*

0.0 0.0' '

1918 1.92 639'F 4

0*

0.738

2028 2.11 642*F O'

O.749

O.619

O.0118 0

N.A.

0.760 0.747 22365' 2.44 655'F (0.024W) 0.743 2276 3.37 627*F None 0.10 0*

0.760

O.724

O.0249 0.094 0.0024 0.772 0.746 2265 3.65 657'F Steps (0.044W)

(0.026W) 0.752 C&D 2406 4.95 639'F 2532 5.69 633*F None Free Same as above for 1495

13.1 646*F Span unpressurized tube with crack Steps offset from the TSP E&F 3220 0.0 0*

0.760

O.726*'

O.0257 0.094 0.0024 0.773 0.752 2148'5' 5.12 621*F Steps 0.755 G&H (0.050W)

(0.026W) 2228 4.70 642*F 2262 5.40 615'F 2403'5' 5.10 634*F s ape \\cpn urticant2 wp6 June 20,1995

=

Test 1.C. Summxry cf Tect Resulta Specimen 2008E, Tube Dia. = 0.745", Gap = 0.025" Bladder Tube Total Total

. Total Exposed Exposed Max.

Min. -

Imk Rate Test Results I% ssure Offset Angle Cradc TW TW TW TW Dia.

Dia.

(psi)

(in.)

Length length Ana length Area (in.)

(in.)

. (in.)

(Max.

(in')

Max.

(in')

Note 1 AP Rate Tw Width)

Width)

(Psi)

(spm)

(*F)

(in.)

(in.)

3220 0.10 Same as above for bladder 1980*'

4.55 639'F Step I pressurization to 3220 psi 5

2028 '

4.84 626*F steps G&H 2095*

4.74 636*F 5

2159 '

5.37 618'F 2305 5.62 622'F Notes: 1. Diametera given are approximately the values at the two edges of the TSP. Diameters greater than the initial 0.745" diameter indicate bulging of the tube at the edges of the TSP as a result of the tube pressurization.

2. Cracks are tight for specimens not pressurized with a bladder and TW area is not applicable.

3. Crack lengths from dye penetrant tests.

4. Crack lengths from toolmaker's microscope. Minimum measurable TW crack opening -0.001"

5. Single leak rate measurement. Other test results are an average of two measurements at comparable APs.

s. ape \\epri\\irtdesk2.erp5,Jurm 17.1:795

r s

1 ~

1 l

TEST 1-7 1

I I

i I

i I

l a

I t

R:nla:Bytwd:Ftgen/IPCTesT:18

s:

4 Test 1-7: Summary cf Test Results Status - June 15,1995 1

~ Test Status i

e Specimen with 0.60" TW crack by dye penetrant at start of test i

e. Completed hot leak tests with crack at TSP edge and 0.10" offset and bladder pressurization to -

. free span burst pressure e Room temperature leak tests following bladder pressurization not complete 2

Summary of Test Results e Shallow slope of leak rate versus AP curve above 2200 psi shows interaction with TSP reduces leak rates Initial slope of leak rate curve up to 2030 psi test point is mom typical of free span slope

- Larger slope and leak rate for CRACKFLO free span predictions supports TSP interaction >

l 2200 psi.

6 e Initial increase in leak rate at 2445 psi after 0.10" offset may indicate reduced TSP restriction on flow after offset e Above 2445 psi, the leak rate tends to decrease due to further interaction with the TSP e Maximum leak rate at any test condition is 3.1 gpm at 2445 psi prior to bladder pressurization ~

' e Following bladder pressurization to 2970 psi (slightly under the free span burst pressure of about j

3035 psi), the leak rate for the crack within the TSP is approximately the same as obtained with 0.10" offset prior to bladder pressurization and less than the maximum 3.1 gpm leak rate Overall Conclusions l

e The SLB leak rate for 0.6" TW crack at start of test is limited to about 3.1 gpm prior to and after i

bladder pressurization

- This indication can be expected to be an upper bound TW length for Byron-1 and Braidwood-l implementing a 3.0 volt APC for which < 0.5 TW lengths would be the largest expected e Large (> about 0.5") throughwall cracks interact with the TSP to limit leak rates including conditions with a 0.10" TW crack outside the TSP

- For this 0.6" TW crack, interaction with the TSP is indicated at about 2200 psi and higher

.)'

' e SLB leak rates following bladder pressurization are essentially the same as obtained for the 0.10" -

offset condition with prior flow pressurization i

l 1

i

.wme.,% i im

Test Plan for (IRBs)

Test 1-7 General Test Information

-

• Utilize large leak test facility testing

• Test 3/4" diameter, specimen 2051A

- Corrosion plus fatigue crack length: Silastic mold dye penetrant - 0.58" OD with 0.60" TW

• Leak test at 615 F except as noted. Testing at > 615 F is acceptable.

• Locate specimen relative to the TSP.per requirements for crack locations within TSP and offset from TSP i

• Tubes shall be free to move within TSP dunng pressunzation or, as a mimmum, the tube shall contact the TSP hole at 180 from the crack being leak tested.

3 i

Test Sequence A. Hot (615 F) leak test with crack inside the TSP and crack tip at edge of TSP at 190'O and 2050 and 2335 psi AP; B. Measure crack opening length', diameter, area (total lengths and thruwall lengths / width) and evaluate crack tearing extension (beyond corrosion crack length).

l C. Hot (615 F)le'ak test with crack tip 0.10" offset outside TSP at 2335,2560,2700,2800 psi AP up to facility limit i

D. Measure crack opening length, diameter, area (total lengths and thruwall lengths / width) and evaluate crack tearing extension (beyond corrosion crack length).

E. With the crack tip 0.10" offset outside the TSP, pressurize to about 3035 psid with a bladder. If following pressurization, the corrosion crack tip is more than 0.10" outside the TSP, adjust the specimen to obtain 0.10" of the corrosion crack outside the TSP prior to the leak testing of Step G. M'easure the total crack length, the through wall

' l length / width, the exposed throughwall length / width and the tube diameter across the crack flanks including at least 5 points along the crack plus the locations of the edges of the TSP with the crack tip 0.10" offset and at the edge 'of the TSP.

• Report whether the tube is tight or loose in TSP following pressurization, j

F. Hot (615 F) leak test with crack inside the TSP and crack tip at the edge of the TSP at i

2335 and 2560 psi AP j

G. Hot (615 F) leak test with crack tip 0.10" offset outside TSP at 2335 and 2560 psi AP j

H. R.T. leak test with crack tip 0.10" offset outside TSP at 2335 and 2560 psi AP j

I. Measure corrosion throughwall length and length versus depth profile.

j e

c\\ ape \\eprt\\telrnper.395.Jurw 19,112 m -

c.;

Test 1-7 Indications Restricted From Burst Leak Rate Tests (as-measured, without adjustment to reference conditions) 10 g.

I

(

. f _..

^

Cornered. HT l'

+ Offset 0.1, HT I

• O offset 0.10.H7,2970

{

..e - - o

.. o..carea. HT297o m

^

0-1

• *...L o 1

a e-D' i

o i

IfdM IWW 2tMe 23m 24 2 28 0 2WU Smc Ap(psi)

Test 1-7 Indications Restricted From Burst Leak Rate Tests (Normalized to Tp=615*F and ps=15 psia Conditions) 10 0 l

}

I g..

__,___p _ _,_

N-N I

-.b i

l 4 __

-}-

i i

I

.. j.

_4._

I l

i

(

. l, a

cwe<eo.m

-e-oftw o.to,HT Ii o oftw o io, HT,2970 j

• cefuered.HT2970 g

.a o

3 i

.s. *

..; s c

i,

.. o.

r I

-s i

l I

l to INO l BW

} tug gym 24gg ggg ggp y,g Ap (psi)

Test 1-7. Summary of Test Results Specimen 2051A, Tube Dia. = 0.747", Gap = 0.025" Bladder Tube Total Total Total Exposed Exposed Mar.

Min.

Leak Rate Test Results Pressure Offset Angle Crack TW TW TW TW Dia.

Dia.

(psi)

(in.)

Length Length Area Length Area (in.)

(in.)

(in.)

(Max.

(in')

Max.

(in')

Note 1 AP Rate Tem p.

Width)

Width)

(psi)

(Epm)

(*F)

(in.)

(in.)

None 0.0 0'

O.60'8' O.60'8' N.A.<2' O.0 N.A.'2' O.748 0.747 1865 2.11 636*F Steps

.58-OD 0.748 A&B g

180*

0.0 0.0' '

2030 2.48 647'F 0*

0.609

O.530

O.0043 0.017 AP 0.759 0.748 2255

2.65 650*F (0.011W)

Tight Opening 0.746 2382'5' 2.22 664*F None 0.10 0*

0.621 0.602 0.0071 0.084 0.00059 0.767 0.747 2323 2.95 668'F Steps (0.014W)

(.014W) 0.746 C&D 180*

0.0 0.0 2445'5' 3.79 648'F 2557 3.17 664*F 2712'5' 2.99 677'F 2800'5' 2.43 690*F 2970 0.10 0*

0.621 0.604 0.0087 0.085 0.00068 0.769 0.748 2233 2.49 647'F Steps (0.018W)

(.016W) 0.748 E&G 180*

0.0 0.0' '

2399 2.99 634*F 2469'"

2.99 638'F s' ape \\epnbrbienk2.wp54une 17.1995

o-Test 1-7. Summary of Test Results Specimen 2051A, Tube Dia. = 0.747", Gap = 0.025" I

Bladder Tube Total Total Total Exposed Exposed Max.

Min.

Leak Rate Test Results Pressure Offset Angle Crack TW TW TW TW Dia.

Dia.

(psi)

(In.)

Length Length Area Length Area (in.)

- (in.)

(in.)

(Max.

(in')

Max.

(in')

Note 1 AP Rate Temp.

Width)

Width)

(Psi)

(epm)

(*F)

(in.)

(in.)

2970 0.00 Same as above for 2970 psi

-2092*'

2.35 639'F Step F bladder pressurization with 5

0.10" offset 2195 '

2.7 623*F

-2270 2.6

'636*F 2426*'

2.65 640*F Notes: 1. Diameters given are approximately the values at the two edges of the TSP. Diameters greater than the initial 0.875" diameter indicate bulging of the tube at the edges of the TSP as a result of the tube pressurization.

l

2. Cracks are tight for specimens not pressurized with a bladder and TW area is not applicable.

3. Crack lengths from dye penetrant tests.

4. Crack lengths from toolmaker's microscope. Minimum measurable TW crack opening -0.001"

5. Single leak rate measurement. Other test results are an average of two measurements at comparable APs.

I e age \\egi\\irbleak2.wp%Iune17,1995

I TEST 2-1 TEST RESULTS ARE NOT YET AVAILABLE I

l l

e R:nla:DyLwd:Stgen/IPCTesT;19

Test Plan for (IRBs) l Test 2-1 i

General Test Information e Utilize large leak test facility testing.

e Test 7/8" diameter, specimen 8161-A

- Corrosion plus fatigue crack length: silastic mold dye pentrant -0.62" OD with 0.515" ID e Ixak test at 615'F except as noted. Testing at > 615'F is acceptable.

e locate specimen relative tc the TSP per requirements for crack locations within TSP and offset

'l 1

from TSP.

e Tubes shall be free to move within TSP during pressurization or, as a minimum, the tube shall

. contact the TSP hole at 180* from the crack being leak tested.

j Test Sequence.

]

A. Hot (615*F) leak test with simulated crack inside TSP and crack tip at edge of TSP at 1800,1900 and 2000 psi AP

- B. Hot (615*F) free span leak test at 2000,2150 and 2335 psi AP l

C. Hot (615'F) leak test with crack tip 0.15" offset outside TSP at 2335, psi AP (adjust, if necessary, i

to the same AP as last test of Step C), 2560,2700 psi AP and another higher AP at facility limit D. Leak Test at R.T. with 0.15" offset starting from the highest AP obtained in Step C and increase to facility limit E. Measure crack opening length, diameter, area and evaluate crack tearing extension (beyond corrosion crack length).

' F. With the crack tip 0.15" offset outside the TSP, pressurize to 4,450 psid with a bladder. If following pressurization, the corrosion crack tip is more than 0.15"_ outside the TSP, adjust the l

specimen to obtain 0.15" of the corrosion crack outside the TSP prior to the leak testing of Step G.

l Measure the total crack length, the through wall length / width, the exposed throughwall length / width and the tube diameter acmss the crack flanks including at least 5 points along the crack plus the locations of the edges of the TSP with the crack tip 0.15" offset and at the edge of the TSP.

]

e Report whether the tube is tight or loose in TSP following pressurization.

l

. G. Hot (615'F) leak test with crack tip 0.15" offset outside TSP at 2335 and 2560 psi AP H. Hot (615*F) leak test with crack tip located at the edge of the TSP at 2335 and 2560 psi AP

)

- I.

R.T. leak test with crack tip 0.15" offset outside TSP at 2335 and 2560 psi AP j

J. Measure corrosion throughwall length and length versus depth profile.

. w % m % x ms

e g

TEST 2-4 a

l

(

)

1 a

i 4

4 i

e

+

i

]

l 4

}

.i K nla'pytned:Stgen/ItcTesT:20

~-

Tc:t 2-4: Summrry cf Tc t Rruits Test Complete, Evaluation Status June 12,1995 Test Status

• 7/8" diameter specimen 4C218 with,0.60" OD,0.29" TW crack by dye penetrant at start of test

- Two TW lengths of 0.33" and 0.12" after flow tests with 0.15" offset

- Two TW lengths of 0.38" and 0.28" after 5550 bladder pressurization

- Bobbin voltage of 11.4 volts for specimen prepared in doped steam is expected to be low based on prior experience

• All tests complete - with and without bladder pressurization Summary of Test Results

• Leak rates for the crack at edge of TSP, free span and offset 0.15" result in leak rates typical of free span behavior

- The flow pressure increases extended the length of the inital TW crack to 0.33" and opened a second TW crack of 0.12". High slopes ofleak rate versus AP indicate ligament tearing up to about 2200 psid

- Maximum tube diameter of 0.878" after test also indicates a low likelihood of tube to TSP contact at test conditions

- Small slope of room temperature tests up to 2716 psid may be due to hysterisis effect on 2534 psid measurement since this test AP is 37 psi lower than the prior pressurization

• Bladder pressurization to a AP of 4125 psi did not result in crack faces contacting the TSP ID and leak rates are significantly lower (about factor of 2) than obtained with bladder pressurization at the estimated free span burst pressure of 5550 psi

- Test 4-1 results show that further increases in bladder pressurization above the free span burst pressure do not result in increased leakage

• For this indication, the leak rates following bladder pressurization to 4125 psi with the crack inside the TSP are approximately the same as obtained prior to bladder pressurization

• For 0.15" offset and bladder pressurization to the free span burst pressure of 5550 psi, the leak rates at SLB conditions are about 1.5 gpm and about 50% higher than with the crack inside the TSP and the crack tip at the edge of the TSP

- Pressurization opened the longest throughwall crack to 0.382" (> 1.0 mil wide) with an average TW width of 0.010" and the second TW to 0.284" with an average TW width of 0.004". A TW length > 1.0 mil wide of 0.076" with an average width of 0.010" was exposed outside the TSP.

3 a apr\\cimbri, leak 2 wp54une 17,11795

e Tc.t 2-4: Summ:ry cf Tc t Rzults Test Complete, Evaluation Status June 12,1995 Assessment of EPRI Cold Test to Reference Hot Conditions Leak Rate Adjustment Procedure

• Pressurization by primary flow pressure Calculated cold test adjustment factor of 0.58 brings cold tests results into very good agreement with hot test results

• Bladder pressurization

- EPRI adjustment procedure for temperature factor,, modified to exclude ratio of flow stresses and Young's modulus as these factors are intended to reflect the effect 4

of temperature on crack opening area, which is not applicable to ble.dder pressurized specimens

- Calculated cold test adjustment factor of 0.45 shows good agreement with hot test results although unexpected high hot data point at 2400 psi leads to a residual uncertainty in the comparison Overall Conclusions

• Initial TW crack lengths of about 0.29", OD = 0.60" (Average length = 0.445") do not result in interaction with the TSP ID at SLB conditions and the leak rates for the indication inside the TSP behave as free span indications with an SLB leak rate < 0.4 gpm

• Although this indication would not burst at SLB conditions, bladder pressurization tests were performed to bound the leak rate at pressures of 4125 psi and 5550 psi (estimated free span burst pressure for this indication)

• Bladder pressurization to 4125 psi resulted in a leak rate approximately the same as the free span leak rate for the indication inside the TSP and about 0.65 gpm with the crack 0.15" offset outside the TSP i

• Bladder pressurization to the free span burst pressure of 5550 psi resulted in SLB leak j

rates of < 1.1 gpm with the crack inside the TSP and < 1.7 gpm with the crack offset i

0.15" outside the TSP

• Comparisons of cold and hot test results strongly support the EPRI cold to hot leak rate adjustment procedure and, thereby, the adequacy of performing leak rate tests at cold conditions j

i l

I e

l a ape \\epn\\arthak2 m AJune 17.1995

Test Plan for (IRBs)

Test 2-4 General Test Information

• Utilize small leak test facility fbliowed by testing in large leak test facility

• Test 7/8" diameter specimen 4C 218

- Crack length: Dye Penetrant - 0.60" with 0.29" TW; UT - 0.62" with 0.40" TW

• Leak test at 2 615 F except as noted

• Tubes shall be free to move within TSP during pressurization or, as a minimum, the tube shall contact the TSP hole at 180 from the crack being leak tested.

Test Sequence A. Leak test with crack centered at 1500,1700 and 2000 psi AP B. Free span leak test at 2000,2335 and 2560 psi AP C. Leak test with crack 0.15" offset outside TSP at 2560 and 2720 psi AP (facility limit)

• Move tube by 0.15" relative to the TSP D. Leak test at R.T. with 0.15" offset starting from the highest AP obtained in Step C and increase to the facility limit E. Measure crack opening length, diameter, area and evaluate crack tearing extension (beyond corrosion crack length).

Decontaminate the specimen The following tests are to be performed in the large leak test facility with a collar that i

provides a 25 mil diametral gap relative to the tube diameter prior to any of the above leak testing:

F. With the crack tip 0.15" offset outside the TSP, pressurize to about 4000 psid with a bladder. If following pressurization, the corrosion crack tip is more than 0.15" outside the TSP, adjust the specimen to obtain 0.15" of the corrosion crack outside the TSP prior to the leak testing of Step G. For each crack (2 expected), measure the total crack length, the through wall length / width, the exposed throughwall length / width and the tube diameter across the crack flanks including at least 5 points along the crack plus the locations of the edges of the TSP with the crack tip 0.15" offset and at the edge of the TSP.

• Report whether the tube is tight or loose in TSP following pressurization.

G. R.T. leak test with corrosion crack tip 0.15" offset outside TSP at 2335 and 2560 psi AP H. R.T. leak test with crack inside the TSP and the crack tip located at the edge of the TSP at 2335 and 2560 psi AP I. Repeat Step F with a bladder pressurization of 5500 psid J. R.T. leak test with corrosion crack tip 0.15" offset outside TSP at 2335 and 2560 psi AP K. R.T. leak test with crack inside the TSP and the crack tip located at the edge of the TSP at 2335 and 2560 psi AP L. Hot (615 F) leak test with corrosion crack tip 0.15" offset outside TSP.at 2335 and 2560 psi AP M. Measure corrosion throughwall length and length versus depth profile.

e \\mpr\\eprt\\teirspar.39EJune 19, lim 4 e

o Test 2-4 Indications Restricted From Burst Leak Rate Tests (as-measured, without adjustment to reference conditions) i 10 tilWN!

tepecwnen 4C210 Crack Lonym

' ~ -

1 00 ID Tiene in Test

_C.C

- Q

..ee=-

• ? O

. #',s g.......n f,A

• 0.60 0 29 Start of Test 0 61 0 33 After 0.15' ONeot

-"' 1

_ _ j *,, 4 i ssman -

0 61 0 29' After 4125 Pressure m-t 0 56 0 28' After 6550 Pressure 2 9 "S

",m

' ' ~ '

0 62 0.38' After 5550 Pressure

- ~ - -

+

f Test Sequence

g y;;'

• >= approx 1 mN crack operung t

.,j,,

^

Corwered, HT s

[ O ttym.

+ Freespan, HT 3

5,

.J_.

r. %.g

-e-Offset 01$.HT

' ~'

'..I N ^

--#--Offset 0.15,RT y

'N_ _.. _... _ Offset 0.15. RT.4125 E

{

~

- O - Centered, RT.4125

(.

j om.

.

• D - Onset 0.16. RT.6550 u..__.

• D *

• Offset 0.15. HT.6550 oimio.

^-~jNote 1;Speomen previously un-expanded t

l Note 2. Pre-press. with bladder to 4125 psid Note 3. Pre-press. with bladder to 5550 psd Dimmi IMMI INm llidN) 2W N) 22fM) 24W) 2NW) 2111W1

{

AP (psi)

I Test 2-4 Indications Restricted From Burst Leak Rate Tests (Normalized to 615'F and 15 psi Secondary Pressure)

{

.Z

~~

)).

_ _. _ ~. _.... _ - -, _ _ _ -

3,

• I*

-O-Centered. HT D,,...

r o' _

Isote al

--*-Fmespan, HT i*"*

.7~

~ ~ E~Z ~.1. _ _._ ' ~Z~Z.__..

D"

' ~ ~ '

~

--6-ONsel.15.HT E

--- 7

- ---- g--g

+mt m

.. Offset.15.4125, RT

- C - Centered, RT.4125 g

• D Offset.15. RT,6550 j

• -Centerea RT,6560

/

-- O Offset 015. HT. 5550

= = -

= _ _ -

=

==:=. :

=

T,~"~.._ _7 T.T-^

. '.~Z -'-~~~ T.T. 2l Note 1[ Z. 1 1

e--,,-...._.--..e.

. _ _., e Note 1: Specimen previously un-expanded O.

Note 2: Pre-pressunzed with bladder O 4125 psid Note 3: Pre-pressunzed with bladder at 5550 psd o ostm IND llM10 2W10 2200 2MNI 2NN) 2KfD Ap (psi)

Test 2-4 Indications Restricted From Burst Leak Rate Tests (as-measured, without adjustment to reference conditions) l I##

.._.._s__.

7 a

.. L.

_ 4

.. ~. - _.

-.,D*r***.****.,

..__L,.._...-

[

CE _. _

_.3 t

-/~ **

f

+ 0Naat 0.15.RT g

+ Offset 0.15.HT f

1.0 tam 4

4...

-

• O -

• Onset 0.15. RT.6550

...,... _ ~ _ _ _ _ _.. _......

J

_.~

._.m-__.

i

....n..

I l' Note 1; Specimen previously un-expanded Note 2. Pre-press. with bladder to 5550 psid

}

....e a

tem num iam 2mm 22im 2*e 2sm 2mm Ap (psi)

?

i Test 2-4 Indications Restricted From Burst Leak Rate Tests (Normalized to 615'F and 15 poi Secondary Pressure) 10 mstm i

i

-i+h.-._-.+

w e.wa-h 4._,.eeen e-

+ Onset.15, RT

[

1~

{

me #i.

,. :.2~.

-*-ON aus.wr D***~,*

c' E

D

• Onset.16. HT.S$50 eg i mum a

~ ~ ' * ~

~

= = S

• Oftset 0.15. HT. 6650

[

M

%d _._ _,

Note 1: Specimen previously un-expanded j

Note 2; Pre-pressunzed with bladder at 5550 psid c itac INNI IWW 2ium 22(m 24m 2NM 2Em Ap (psi) i

Test 2 4 Summary of Test Results Specimen 4C-218, Tube Dia. = 0.875", Gap = 0.025" Bladder Tube Total Total Total Expose Expose Max.

Min.

Leak Rate Test Results Pressure Offset Angle Crack TW TW d

d Dia.

Dia.

(psi)

(in.)

Lengt Length Area TW TW (in.)

(in.)

h (Max.

(in')

Length Area Note 1

~

(in.)

Width)

(Max.

(in')

AP Rate Temp (in.)

Width)

(Psi)

(gpm)

(in.)

(*F) l None 0.0 270*

0.60

O.29

N.A.

O.0 N.A.

O.875 N.A.(2>

1504 0.0009 613

-0 Step A 90*

0.60'8' O.0

1645 0.0033 511 1941 0.025 570 None Free 1968 0.052 590 span Step B 2238 0.21 559 2430 0.34 568 None 0.15 2481 0.40 551 Step C 2549 0.47 561 2571 0.49 564 None 0.15 270*

0.611'8' O.33

Tight 0.0 0.0 0.878 0.877 2534 0.81 R.T.

Steps 0.875 D&E 90*

0.570

O.12'8' Tight 0.0 0.0 2716 0.87 R.T.

l a apeicpri\\irtdesk2.wp5. June 20.1995

i Te:t 2-4 Summary of Te:;t Results Specimen 4C-218. Tube Dia. - 0.875", Gap = 0.025" Bladder Tube Total Total Total Expose Expose Max.

Min.

Leak Rate Test Results Pressure Offset Angle Crack TW TW d

d Dia.

Dia.

(psi)

(in.)

Lengt Length Area TW TW (in.)

(in.)

h (Mar.

(in')

Length Area Note 1 (in.)

Width)

(Max.

(in')

AP Rate Temp l

(in.)

Width)

(psi)

(gpm)

(in.)

(*F)-

4125 '

O.15 270*

0.609

O.286

0.00086 0.032 0.00009 0.881 0.877 2325 1.25 R.T.

Steps (0.003W)

(0.003W) 0.874 F&G 90*

0.570

Tight Tight 0.0 2535 1.38 R.T.

0*-180*

0.875 0.875 0.875 45*-225' O.876 0.876 0.875 135*-315' O.877 0.876 0.875 4125 0.00 270*

Same as above for 4125 psi 0.881 0.875 2345 0.56 R.T.

Step bladder pressure with 0.15" 0.875 II 90*

offset 2548 0.93 R.T.

0*-180*

0.875 0.875 0.875 45*-225*

0.876 0.876 O.875 135*-315' O.877 0.875 0.876 e apc\\epruirt> leak 2 wp6, June 17,1995

._.-i.

-r m.

.m

... m

.m.

r-*

Test 2-4 Summary of Test Results Specimen 4C-218, Tube Dia. = 0.875", Gap = 0.025" Bladder Tube Total Total Total Expose Expose Max.

Min.

Leak Rate Test Results Pressure

. Offset Angle Crack TW TW d'

d Dia.

Dia.

(psi)

(in.)

Lengt Length Area TW TW

'in.)

(in.)

h (Max.

(in')

Length Area Note 1 (in.)

Width)

(Mar.

(in')

AP Rate Temp (in.)

Width)

(Psi)

(gpm)

(in.)

(*F) 5550 0.15 270*

0.617 0.382 0.00382 0.076 0.00076 0.897 0.885 2253 3.11 R.T.

Steps (0.010W)

(0.010W) 0.874 I,J &

L 90' O.580 0.284 0.00114 0.0 0.0 2453 3.37 R.T.

(0.004W) 0*-180*

None 0.874 0.874 2329 1.25 644'F 0.876 45'-225' None 0.881 0.879 2403""

2.05 632'F 0.876 135'-315' None 0.882 0.879 2530 1.63 645'F 0.877 5550 0.0 270*

Same as above for 5500 psi 0.897 0.876 2258 1.96 R.T.

Step bladder pressum with 0.15" 0.875 K

90*

offset 2473 2.18 R.T.

0*-180*

0.874 0.874 0.875 45'-225' O.881 0.877 0.877 135*-315' O.882 0.877 0.877 a.mpe\\epri\\irtdenk2 wp6, June 20.1995 m

Test 2-4 Simmnry cf Test Results Specimen 4C-218, Tube Dia. = 0.875", Gap = 0.025" Bladder Tube Total Total Total Expose Expose Max.

Min.

Leak Rate Test Results Pressure Offset Angle Crack TW TW d

d Dia.

Dia.

(psi)

(in.)

Lengt Length Area TW TW (in.)

(in.)

h (Max.

(in')

Length Area Note 1 (in.)

Width)

(Max.

(in')

AP Rate Temp (in.)

. Width)

(P8i)

(gPm)

(in.)

(*F)

Notes: 1. Diameters given are approximately the values at the two edges of the TSP. Diameters greater than the initial 0.875" diameter indicate bulging of the tube at the edges of the TSP as a result of the tube pressurization.

2. Cracks are tight for specimens not pressurized with a bladder and TW area is not applicable.

3. Crack lengths from dye penetrant tests

4. Crack lengths from toolmaker's microscope. Minimum measurable TW crack opening -0.001"

5. Single leak rate measurement. Other test results are an average of two measurements at comparable APs.

s' ope \\ epi \\irbleak2 wp64ane 17.1995

TEST 2-7 l

4 I

l l

i

\\

4 i

k'n16:Dytwn1: St gen /IPCtesT:21

Tect 2-7: Summery cf Tc:t Reruits Status - June 17,1995 Test Status 3/4" diameter specimen with 0.577" TW crack,0.66" OD by dye penetrant at start of e

test Completed cold leak tests with crack at TSP edge and freespan and hot leak tests with 0,10" offset and following bladder pressurization

• Test complete except for post pressurized cold test Summary of Test Results

• The flattening of the leak rate slope above about 2300 psi AP indicates interaction of the crack face with the TSP ID and the SLB leak rate is bounded by about 3 gpm

• Leak rates below 2300 psi are typical of free span leak rates and are in good agreement with analytical (CRACKFLO) analyses for the leak rate

• Bladder pressurization to the free span burst pressure of about 3700 psi did not significantly affect the leak rate from that obtained by prior flow pressurization

• Following bladder pressurization to the free span burst pressure, the leak rate with the crack inside the TSP of about 2.3 gpm is less than the 3 gpm obtained with flow pressurization in the offset condition Overall Conclusions

• Flow pressurization to a 2300 psi AP resulted in interaction of the crack face with the TSP ID and resulted in an upper bound Icak rate of about 3 gpm l

• After crack face interaction with the TSP at 2300 psi, the leak rate did not further increase including subsequent leak rate tests after bladder pressurization to the free span burst pressure of about 3700 psi l

I I

s apc\\epn\\artdeak2 wp6, June 17,1995 i

4 4.

Test Plan for (IRBs)

Test 2-7 General Test Information

• Utilize large leak test facility testing

• Test 3/4" diameter, corrosion plus fatigue specimen 2051E

- Original corrosion crack length: Silastic mold dye penetrant - 0.66" with 0.577" TW

- Specimen fatigued to obtain ID TW length

• Leak test at room temperature with selected 2 615 F tests.

• Locate specimen relative to the TSP per requirements for crack locations within TSP and offset frcm TSP

• Tubes shall be free to move within TSP during pressurization or, as a minimum, the tube shall contact the TSP hole at 180 from the crack being leak tested.

Test Sequence A. R.T. leak test with simulated crack inside TSP and crack tip at edge of TSP at 1800, 1900 and 2000 psi AP B. R.T. free span leak test at 2000,2150 and 2335 psi AP C. Hot (615 F) leak test with crack tip 0.10" offset outside TSP at 2335, psi AP (adjust, if necessary, to the same AP as last test of Step C),2560,2700 psi AP and another higher AP at facility limit D. Measure crack opening length, diameter, area and evaluate crack tearing extension (beyond corrosion crack length).

E. With the crack tip 0.10" offset outside the TSP, pressurize to 3650 psid with a bladder.

If following pressurization, the corrosion crack tip is more than 0.10" outside the TSP, adjust the specimen to obtain 0.10" of the corrosion crack outside the TSP prior to the leak testing of Step G. Measure the total crack length, the through wall length / width, the exposed throughwall length / width and the tube diameter across the crack flanks including at least 5 points along the crack plus the locations of the edges of the TSP with the crack tip 0.10" offset and at the edge of the TSP.

• Report whether the tube is tight or loose in TSP following pressurization.

l F. Hot (615 F) test with crack tip located at the edge of the TSP at 2335 and 2560 psi AP l

G. Hot (615 F) leak test with crack tip 0.10" offset outside TSP at 2335 and 2560 psi AP l

H. R.T. leak test with crack tip 0.10" offset outside TSP at 2335 and 2560 psi AP

1. Measure corrosion throughwall length and length versus depth profile.

l l

s \\npr\\cpr1Wirspee.mfS.Jurw 19,1W

4 Test 2-7 indications Restricted From Burst Leak Rate Tests (ee-measu:od, uthout ediusement to reference conditione) 10.050 1

I A

_.____1 4

d.

i Test Sequence

. - ~..

^ Consorst M

, p...,..,.

j

• s*E _.4.....,....

1 l

.. o. caw.a.m.sm j

i

.......,,,,3.

4 Meseea aosone ponal i

/

teoo0 1400 1600 1800 3m 2200 2 410 2000 2suo Ap (pol)

Test 2-7 Indications Restricted frone Burst Laak Rate Tests (Leak Rate Test Dets Nonnalized to 615T and 15 pel Secondary Pressure) 80.0000 L __

--.__1..

I Elevated flow Rate Das e Hysterees I

from Prior Higher Pressutuaton

\\.

...O

• T*r4 7

........ ~ >.

P j

o_ c,,,,,,

+ Freescan, RT I

==4==O# set 10.HT n,-

a:

3 4

l'"'wa sea osie conn l i

K I

...... ~. - _

j

)

e inao 1600 1800

• 0u0 2200 2400 2e00 2600 M M) i

O Test 2-7. Summary of Test Results Specimen 2051E, Tube Dia. = 0.749", Gap = 0.025" Bladder Tube Total Total Total Exposed Exposed Max.

Min.

Leak Rate Test Results Pressure Offset Angle Crack TW TW TW TW Dia.

Dia.

(psi)

(in.)

Length Length Area Length Area (in.)

(in.)

(in.)

(Max.

(in')

Max.

(in')

Note 1 AP Rate Temp.

Width)

Width)

(psi)

(gpm)

(*F)

(in.)

(in.)

None 0.0 0*

0.66'8' O.5772' N.A!

O.0 N.A.

O.749 N.A.

1775 1.30 R.T.

Step A 180' O.0 0.0

1878 1.45 R.T.

1970 1.04 R.T.

None Free 0-180' O.667

O.515

O.00090 0.0 0.0 0.756 0.748 1945 1.99 R.T.

span (0.002W) 0.749 Step B 90-270' O.0 0.746 0.748 2085 2.62 R.T.

0.746 2228 4.44 R.T.

None 0.10 0-180*

2155'5' 3.72?

638'F Steps 5

C&D 90-270' 2305 '

4.30?

642*F l

2662 3.06 663*F 3700 0.0 0-180' 23675' 2.98 655'F Steps E&F 90-270' 2439'5' 2.95 668'F 2570*'

2.97 674'F 2599*'

3.11 672*F s spe\\eprthrWeak2 wpSJune 17.1995

Tect 2-7. Srmmrry of Test Resulta Specimen 2051E, Tube Dia. = 0.749', Gap = 0.025" i

Bladder Tube Total Total Total Exposed Exposed Max.

Min.

Leak Rate Test Results Pressure Offset Angle Crack TW TW TW TW Dia.

Dia.

(psi)

(in.)

Length Length Area Length Area (in.)

(in.)

(in.)

(Max.

(in')

Max.

(in')

Note 1 AP Rate Temp.

Width)

Width)

(P8i)

(gPm)

(*F)

(in.)

(in.)

3700 0.10 0-180*

2123*

3.23 633*F Step G 90-270' 2196 3.04 643*F 2256*

3.51 620'F 2335'5' 3.45 633*F 2437 3.74 626*F Notes: 1. Diameters given are approximately the values at the two edges of the TSP. Diameters greater than the initial 0.749" diameter indicate bulging of the tube at the edges of the TSP as a result of the tube pressurization.

2. Cracks are tight for specimens not pressurized with a bladder and TW area is not applicable.

3. Crack lengths from dye penetrant tests

4. Crack lengths from toolmaker's microscope. Minimum measurable TW crack opening ~0.001"

5. Single leak rate measurement. Other test results are an average of two measurements at comparable APs.

e s apr\\epri\\erldeak2 wp54tme 17.1995

1 l

TEST 2-10 l

k >n1* >erbwo: ste.nexecr..T 22

l

~

x

,s l

Test 2-10: Summary of Test Results 1

Status - June 17,1995 i

Test Status

*' 3/4" diameter specimen with 0.425".TW, 0.551" OD by dye penetrant at start of test

( Completed hot leak tests with crack at TSP edge and 0.10" offset and following bladder.

pressurization to the free span burst pressure

• Test complete except for post-pressurized cold test i

Summary of Test Results

• The slope of the leak rate versus AP curve indicates essentially free span leak rates with no TSP interaction up to the maximum AP of 2300 pai tested under flow pressurization conditions

- The mnimum leak rate tested is about the limit of the small leak test facility used for this test

• The maximum measured leak rate for this 0.425" TW indication was about 0.85 gym at-2300 pai which would extrapolate to about 1.2 gpm at 2560 psi Bladder pressurization to 3850 pai at 0.10"' offset asulted in leak rates at SLB 1

e conditions of about 1.4 gprn with the crack inside the TSP. No increase in flow rate was observed with the crack offset 0.10" from the TSP.

l

• Following bladder pressurization at 0.10" affset to the free span burst pressure of 4960 I

psi, the SLB leak rate at the 0.10" offset condition was about 1.50 gpm

-- The increase in leak rates following bladder pressurization is typical for indications which do not show interaction with the TSP under flow pressurization conditions Assessment of EPRI Cold Test to Reference Hot Conditions Leak Rate Adjustment Procedure Pressurization by primary flow pressure

- Calculated cold test adjustment factor of 0.52 brings cold test results to slighly higher (about 5%) than the hot test results which indicates that the adjustment procedure is slightly conservative for adjusting cold test results to reference hot conditions Overall Conclusions

• The initial TW crack length of 0.425", OD = 0.551" (Average length = 0.488") for this test does not result in interaction with the TSP ID at SLB conditions and the leak rates for the indication inside the TSP behave as free span indications with an SLB leak rate of about 1.2 gpm

• Although this indication would not burst at SLB conditions, bladder pressurization tests were performed to bound the leak rate at pressures of 3850 pai and 4960 psi (estimated free span burst pressure for this indication)

• The SLB leak rate for the 0.10" offset condition following bladder pressurization to the free span burst pressure was about 1.5 gpm, which is <10% higher than obtained for i

the crack within the TSP

• Bladder pressurization to tlie free span burst pressure resulted in SLB leak rates about 70% higher than obtained by flow pressurization, which is typical for the shorter indications for which the crack faces do not interact with the TSP under flow l

pressurization conditions j

i

.- - w mm

6

.4 Test Plan for (IRBs)

Test 2-10 General Test Information e Utilize small leak test facility followed by large leak test facility testing e Test 3/4" diameter, corrosion specimen 2051B Crack length: Silastic mold dye penetrant - 0.551" OD with 0.425" TW e Leak test at 2: 615' with selected mom temperatum tests i

e I.ocate specimen relative to the TSP per requirements for crack locations within TSP and offset fmm TSP e Tubes shall be free to move within TSP during pressurization or, as a minimum, the tube shall contact the TSP hole at 180* from the crack being leak tested.

Test Sequence A. Hot (615 *) leak test with simulated crack inside the TSP and the crack tip at edge of TSP at 1800, 1900 and 2000 psi AP B. Hot (615 *) free span leak test at 2000,2150 and 2335 psi AP C. Hot (615*) leak test with crack tip 0.10" offset outside TSP at 2335,2560 and 2750 (or facility limit) psi AP Note: If at any time during this test it appears that the facility limit for measuring leak rate is being approached, increase the AP to about the facility limit and terminate testing in the small loop. Testing will than be continued in the large loop.

D. Leak test at R.T. with crack tip 0.10" offset outside TSP at the 2750 AP psi or highest pressure obtained in Step C and increase the AP to the highest AP obtainable at mom temperature.

E. Measure crack opening length, diameter, area and evaluate crack tearing extension (beyond -

corrosion crack length).

Decontaminate the specimen for later testing in large loop facility F. With the crack tip 0.10" offset outside the TSP, pressurize to 3800 psid with a bladder. If following pressurization, the corrosion crack tip is more than 0.10" outside the TSP, adjust the specimen to obtain 0.10" of the corrosion crack outside the TSP prior to the leak testing of Step G.

Measure the total crack length, the through wall length / width, the exposed throughwall length / width and the tube diameter across the crack flanks including at least 5 points along the crack plus the locations of the edges of the TSP with the crack tip 0.10" offset and at the edge of the TSP.

e Report whether the tube is tight or loose in TSP following pressurization.

Move specimen to the large leak test facility for the following tests. Either the hot test sequence or the cold test sequence (lined out) are acceptable and selection of hot or cold testing should be based on most efficient completion of the tests.

G. Hot (615'F) test with crack tip located at the edge of the TSP at 2335 and 2560 psi AP H. Hot (615*F) leak test with 0.10" offset outside TSP at 2335 and 2560 psi AP j

I.

Repeat Step F with a bladkr pressurization of 4920 psid J. Hot (615*F) test with crack tip located at the edge of the TSP at 2335 and 2560 psi AP K. Hot (615'F) leak test with 0.10" offset outside TSP at 2335 and 2560 psi AP L. R.T. leak test with 0.10" offset outside TSP at 2335 and 2560 psi AP i

M. Measure corrosion throughwall length and length versus depth pmfile.

.www n e

o

)

I i

l I

Test 210 indications Restricted From Burst Leak Rate Tests (ae-measured, without adjustment to tolerance conditions) 10 0000

.~.y..~-.

i r.

~

'.,.L..a 3

.._.. - -. - 4.+. -

m..+-.

s.-.,,'

'., ;. 4 ' l.

.~ i

-4.-

s.

8 I.

s

.e j

e i

n l

s 1

i 4,

- i !

~

I s

t i

l,

. a,.

1m.-

t Test Sequence

^

t

) l

! l l I

Cenessee. HT f

! l I

ol O ~

, HT

.=

l k

F l l l-)*g l

g

==4--ONeet c.10.HT

,no -

4.

==4--Onest e.10.AT

-4..,.-..

? '

~4

-- 9 * *. p * -

• * *

• C*'es=L Hats 0s0 L. a --

f. *

• Onnet C.10.MT.3440

-a 4

4

--- ~...

e

= 4 ** Cartered.HT.4900 l e I e

- - + - - - - - - *

-7

= S - 08sel O.10.HT.4000 I

1 !.

t i

l i >

i.,. -

s, e

i i

l-I' e

l 4

i j

j 0 1000 1400 1800 1800 2000 120 3400 3000 Ap (pel)

Test 2-10 Indications Restricted From Burst Leak Tests (Normailaed to SIST and 16 pel Secondary Preneuro)

I 10 0000 _......_._

.~.

....y

.4

_q a

~. p 7._-

1 1

i n,...

_-r...

6 t

4 6

AM " *" U ka

.*.9 i

E dr

- O--Comers 1 MT 1 0000

,,,,y

- -. _-.,_ y

• 44 g

y

~

~

+ 0Psat.10.HT e

t

--*==0rset.10. RT I

Y 2....

• O = Comosed.HT.3060

• * *

• Cfteet 0.10.3060 i

- 4 = CorneretL HT. 4980

- ~..

.... -........ Onset 010.HT 4980

..i..

... +.. * -

.a...

j

.e.

.+

,....-e.-.

..=e,..,

1 l

l 4 0400 1600 1000 2000 2230,

2@

M 2300 AP (P80

I 4

Test 2-10. Summary of Test Results Specimen 2051B, Tube Dia. = 0.74F, Gap = 0.025" Bladder Tube Total Total Total Exposed Exposed Max.

Min.

Leak Rate Test Results Pressure Offset Angle Crack TW TW TW TW Dia.

Dia.

(psi)

(in.)

Length Length Area Length Area (in.)

(in.)

(in.)

(Max.

(in')

(Max.

(in')

Note 1 AP Rate Temp.

Width)

Width)

(Psi)

(epm)

(*F)

(in.)

(in.)

None 0.0 0'

O.551'8' O.425

N.A.*

0.0 N.A.<2' O.750 0.748 1760'5' O.19 540*F Step A 0.749 90' O.0 0.0

0.748 0.749 1823*'

O.27 559'F 0.748 18875' O.35 561*F 1924*'

O.36 560*F None Free 1963*'

O.42 553*F span 5

Step B 2095 '

O.64 571*F 2201*'

O.84 584'F None 0.10

-0.005 2198'5' O.84 584*F Step C 5

2242 '

O.91 586*F None 0.10 0*

0.554

O.425<a' N.A.'8'

-0.005 N.A.*

0.750 0.749 2154*'

1.35 R.T.

Steps 0.749 D&E 90*

0.0 0.748 0.748 2288 '

1.56 R.T.

5 0.748 1

e ape \\epn \\irtdcak2 wp5, June 20,1995

.._____m

9 Test 2-12. Summary cf Test Results Specimen 2051B, Tube Dia. = 0.749", Gap = 8.925" Bladder Tube Total Total Total Exposed Exposed Max.

Min.

Leak Rate Test Results Pressure Offset Angle Crack TW TW TW TW Dia.

D!a.

(psi)

(in.)

Length Length Area Length Area (in.)

(in.)

(in.)

(Max.

(in')

(Max.

(in')

Note i AP Rate Temp.

Width)

Width)

(p.;)

(gpm)

(.y)

(in.)

(in.)

~,

3850 0.0 0*

2286'"

0.84

-634*F Steps F&G 90*

23375' O.8a 648'F 2455 1.39 636*F 3850 0.10 0*

2307 0.74' 637'F 90*

2439*

0.95 620*F 2472*

0.91 630*F 4960 0.0 0*

2146*

1.29 632*F Steps IAJ 90*

2178'5' 1.18 636*F 2340*

1.37 619'F 2366*'

1.37 629'F 4960 0.10 0*

2145 1.29 636*F Step K 90*

2198*'

1.40 611*F 2346*

1.50 619'F s apr \\epre)whicek2 eph,lurer20. 1995

m Test 2-10. Summary of Test Results '

Specimen 2051B, Tube Dia. = 0.749", Gap = 0.025" Bladder Tube Total Total Total Exposed Exposed Max.

Min.

Leak Rate Test Results Pressure Offset Angle Crack TW TW-

.T W TW Dia.

Dia.

(psi)

(in.)

Length Length Area Length Area (in.)

(in.)

(in.)

' (Max.

(in')

(Max.

(in')

Note 1 AP Rate Temp.

Width) -

Width)

(psi)

(gpm)

(*F)

(in.)

(in.)

Notes: 1. Diameters given are approximately the values at the two edges of the TSP. Diameters greater than the initial 0.875" diameter indicate bulging of the tube at the edges of the TSP as a result of the tube pressurization.

2. Cracks are tight for specimens not pressurized with a bladder and TW area is not applicable.

3. Crack lengths from dye penetrant tests

4. Crack lengths from toolmaker's microscope. Minimum measurable TW crack opening -0.001"

5. Single leak rate measurement. Other test results are an average of two measurements at comparable APs.

e apr\\epribrbleak2 wp64ene 17.1995 "Yvgr--

iry, e myg yw $ y+g+ w w gywg,.

myig t'q g www*gv WW h w-eg-*

99*6TM'84*'--tW'""iirmt'Wwv*v't"~v-'VT**Nt-h-er

--g*-y,"se+r=+'iw1*

rwe, w ww30v+

fr wi F4 t i-w Y v f 'ur wu-r=

w srw v'r e -tw ev' w w e www 's wur wr-ww=

• wi-w--

rr w -rvi m

< w to e w i'

w Ts

-vi e

rur w

l 6

1 1

1 TEST 4-1 1:nla mytw1.Stgen/IPCTesT:23

s Tc:t 4-1: Summery cf Text Reculta Status - June 12,1995 Test Status

• 7/8" diameter specimen with 0.24" TW,0.67" OD by dye penetrant at start of test

- After pressurization to approximate free span burst pressure of about 6000 psi, the specimen includes three TW cracks oflengths 0.606,0.567 and 0.388 inch with maximum crack openings of about 0.020,0.015 and 0.007 inch.

- After pressurization to 8900 psi, the three TW lengths are 0.626,0.603 and 0.408 inch with maximum crack openings of 0.022,0.018 and 0.009 inch. The maximum tube diameters inside the TSP have nearly closed the entire tube to TSP gap.

• Test completed include cold leak tests following bladder pressurizations of 5800 psi (estimated free span burst pressure) with crack inside TSP,6000 psi with 0.15" offset, and at 0.15" offset at pressures of 6800,7725 and 8900 psi

• Tests to be performed are a hot leak test after 8900 psi pressurization and an attempt at another pressurization step at about 9900 psi although the indication could have a free span burst during this latter step.

Summary of Test Results

. Leak rates with the crack within the TSP decrease significantly (about 2.2 gpm at 5800 psi bladder pressure to about 0.8 gpm after 8900 psi at SLB AP = 2560 psid) with increasing bladder pressure as the increasing pressures progressively close the tube to TSP gap due to plastic deformation of the tube while crack opening areas only modestly increase.

- After pressurization to 8900 psi, the crack faces contact the TSP ID over close to 0.6" of the 0.626" TW length. The two largest cracks are 180 from each other and both are bulged such that the gap flow area within the TSP is reduced for both cracks

• Leak rates with the crack offset 0.15" outside the TSP do not significantly change (slight decrease) with increasing bladder pressure

• Leak rates with 0.15" offset are about 3.3 gpm at SLB conditions or about 50% higher than for the crack within the TSP

- Two throughwall cracks are exposed outside the TSP and contribute to the higher leak rate with the 0.15" offset

• The crack opening TW area following pressurization is less than the geometric minimum flow area from the tube in the TSP as developed in WCAP-14273

- Tube to TSP contact at the crack face limits the crack opening area

- Leak rate governed more by crack area than geometry - maximum TW width is O.022" compared to geometrically possible x c = 0.072" s apr \\epn brMenk2 =p5,hme 17,1995

Test 4-1: Summery cf Test Results l

Status - June 12,1995 l

Overall Conclusions

• SLB leak rates for this indication with multiple throughwall cracks up to 0.61" TW after bladder pressurization to about the free span burst pressure are bounded by about 3.3 gpm with 0.15" offset and about 2.2 gpm for the crack within the TSP

• Crack opening areas are limited by the tube to TSP gap following contact of the crack face with the TSP ID and the associated areas are less than the minimum geometric l

flow area formed by the gap

- WCAP-14273 model overestimates the flow area and leak rate

• Bladder pressurizations above the free span burst pressure do not result in increasing leak rates

- Therefore, it is not necessary to include bladder pressurizations above the free span burst pressure in tests following Test 4-1

- The principal effect of further increases in bladder pressure is to close the tube to TSP gap within the TSP due to plastic deformation of the tube diameter l

..r.mw u ga_ n.

s

Test Plan for (IRBs)

Test 4-1 i

i General Test Information 1

• Utilize large leak test facility

• Test 7/S~ diameter specimen 4B 214

- Crack length: Dye Penetrant - 0.67" with 0.24" TW; UT - 0.74" with 0.50" TW

• Leak test at room temperature except as specifically noted

• Tube to TSP diametral gap of 0.025" except per adjustments noted

• Tubes shall be free to move within TSP during pressurization or, as a minimum, the tube shall contact the TSP hole at 180 from the crack being leak tested.

Test Sequence A. Pressurize to 5800 psid with a bladder

• If tube is loose in TSP following pressmization, replace TSP to obtain about 0.001" diametral clearance between the maximum diameter of the crack opening and the TSP hole. This requirement applies following all bladder pressurizations of this test sequence.

B. Room temperature leak test at 2335,2560 psi AP C. Measure crack opening length, diameter, area and evaluate crack tearing extension (beyond corrosion crack length). Estimate corrosion throughwall length.

D. Move crack to 0.15" outside TSP and pressurize to the same pressure as step A

• Move tube by 0.15" relative to the TSP E. Room temperature leak test at 2335,2560 psi AP. If high temperature facility is available, repeat leak test at 615 F.

F. Measure crack opening length, diameter, area and evaluate crack tearing extension (beyond corrosion crack length).

G. With the 0.15" crack position, pressurize with a bladder (and foil if necessary) to about 1000 psi above the prior pressurization step H. Room temperature leak test at 2335,2560 psi AP I. Repeat steps G and H with increases in bladder pressure of 1000 psi increments until bladder / foil pressurization of about 9000 psi is achieved J. At bladder pressurization of about 8900 psi, also perform R.T. leak test with crack centered in the TSP K. At bladder pressurization of about 8900 psi, perform hot (2615 F) leak test with crack tip 0.15 inch offset from the edge of the TSP L. Continue bladder pressurization increases in about 1000 psi increments (initially about 9900 psi) and perform either room temperature or hot leak tests (option to increase l

facility efficiency) at 2335 and 2560 psi with 0.15 inch offset following each pressurization step. Terminate testing when the indication bursts outside the TSP.

M. Measure crack opening length, diameter, area and. evaluate crack tearing extension (beyond corrosion crack length). Measure throughwall corrosion length and corrosion depth verus length profile.

a \\mpr\\cpn\\telreg-c.36Jmie 19, INS

.e t

i Test 4-1 Indications Restrained From Burst Leak Rate Tests i

(as-measured, without adjustment to reference cond;tions) 10 0iMm

-. ~....

..f...

1

__._____...-.l.__4._._.

i

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

1 g

~

-e-one o 35.RT.8000 i

3

-*-offset 015.RT.6900 1

2 i

-o-one o.1s.RT.m5

_j j

l e

-*-onsei o.is.RTwoo 3

-o-centered,RT.8900 a

oo i

i 3

eme 1880 19I6 2fus0 2l00 22tB 2)tN) 2*M) 2 !410 2N10 2HM) 2BfM)

AP (Psi) i Test 4-1 Indications Restricted From Burst Leak Rate Tests (Normalized to Tp=615'F and ps=15 pela Conditions) 10 0 -

t s

i Test Sequence

-+-Confered,RT,5800 Offset 0.15.RT.6000

, Offset 0.15,RT,6900 w

$ 104

• '-Oftset 0.15,RT,7725 E

-*-Offset 015.RT.8900

-G-Centered RT,0900 I

Ut l

INNI IMMI 7tNO 22il0 2eK) 2NM 2NINI

.hM A)

Ap (psi)

Test 4-1 Summary of Test Results Specimen 4B-214, Tube Dia. - 0.876", Gap = 0.023*

Bladder Tube Total Total Total Expose Expose Max.

Min.

Leak Rate Test Results Pressur Offset Angle Crack TW TW d

d Dia.

Dia.

e (in.)

Lengt Length Area TW TW (in.)

(in.)

(psi) h (Max.

(in')

Length Area Note 1 (in.)

Width)

(Max.

(in')

AP Rate Temp.

(in.)

Width)

(Psi)

(gy m)

(*F)

(in.)

5800 00 90*

0.650

O.0 Tight 0.0 0.0 0.901 0.875 2168 3.68 R.T.

270*

0.670

O.24

Tight 0.0 0.0 2293 3.91 RT.

0*

0.610*)

0.0 0.0 0.0 O.893 0.882 180*

0.590'2' O.0 0.0 0.0 45*-225" Crack lengths following 0.897 0.885 bladder pressurization are 0.887 approximately the same as 135*-315" those measured aller 0.15*.

0.896 0.886 offset test 0.886 6000 0.15 90*

0.665 0.606 0.0099 0.099 0.0011 0.901

>0.875 2155 6.21 R.T.

(0.020W)

(0.013W) 0.871 270*

0.676 0.567 0.0067 0.112 0.0008 2350 6.81 R.T.

(0.015W)

(0.009W)

O' O.606 0.388 0.0022 0.0 0.0 0.893

>0.882 (0.007W) 0.881 180*

0.583 0.0 0.0 0.0 0.0 45*-225*

0.897

>0.885 0.881 135*-315' O.896

>0.886 0.881 6800 0.15 Not Measured 2183 5.97 R.T.

s apriemtwedea62 =phJwe 20. I'.N5 m

)i]j Ii)ilIll1) lj!]l l) 111jl{,

e a

s p) mF T.

T.

T.

T.

T.

T.

T.

t lu e*

R R

R R

R R

R T(

s e

c R

t e )m s

4 2

4 7

8 6

5 e

t T

ap 4

1 5

9 1

6 7

Rg 6

6 6

5 6

1 1

e

(

t a

H k

)

5 0

0 0

3 5

3 a

Pi 8

6 5

1 0

3 3

s e

AP 3

1 3

2 4

3 5

(

2 2

2 2

2 2

2 L

1 87 58 64 77 90 98 09 n a ). e 97 98 98 98 78 88 98 iint 88 88 88 88 88 88 88 MDio 00 00 00 00 00 00 00

(

N 1

5 9

0 1

5 9

.)

"3 x a 0

9 9

0 0

9 9

ain 9

8 8

9 9

8 8

20 MD(

0 0

O O

0 0

O i

0

=

sp e

t 7

0 l

a s

a T r 'iW e )n 1

1 u

o 0

0 0

0 0

0 0

0 sG pd A(

0 0

0 0

0 0

0 0

e x

R "7 6

E 0

0 ts8 e0

)

)

T=

e h

)

xh) 3W 2W s

t f

o Wgat.

33 20 0

0 0

0 0

0 o a pd n

dn d

10 1

0 0

0 O

O O

1 1

yi x

TeMi i

r 0.

0 0 e

rD E

L( W(

u 0

0 a e s

(

(

mb ae mu M

5 0

0 r

T l

a 2

9 3

et u

a W e )n t

1 0

0 0

d e o T r 'i S

t o

s 4

T A(

N 0

0 0

0 d f 1 1 af 0

0 0

2 l

o B

b "5 4 -

i ts4 s

1 p0

)

)

)

e h

xh) 6W 3W 8W 0 0

)

n Te aWgat l

t 22 08 09 0

0 t

d n m

oTnMi 2

1 0

9h 60 60 40 0

i 8t ic T

e( W(

0 0

0 i

0 0

0 rw e

l

(

(

(

o p

f e S

s r au kt s

l

)

8 0

7 3

es acg 6

8 1

8 e

anhn 6

6 7

5 mr tore i

TCL O

0 0

0 ap

(

S

'5 e

5 5

1 l

2 g

0' 0

0 2

3 0'

'0 0

2 2

7

'O 8

7 0

8 n

9 5'

9 2

1 2

1 A

5 5

3 4

4 5

1 99 1

7 t

1 e

e n

e ).

5 5

u b s ufi 1

1 0

J f n 6

0 0

0 p

rO(

w tk 1?

ice b

rr rM eu ip

)

5 0

0 d s i

d s e s 2

0 0

e

\\

a e p

7 9

9 e

r

(

7 8

8 a

p lBP s

.l l

ll

o Test 4-1 Summary of Test Results Specimen 4B-214, Tube Dia. = 0.876", Gap = 0.023" Bladder Tube Total Total Total Expos Expose Max.

Min.

Leak Rate Test Results Pressure Offset Angle Crack TW TW ed d

Dia.

Dia.

(psi)

(in.)

Length Length Area TW TW (in.)

(in.)

(in.)

(Max.

(in')

Lengt Area Note 1 Width) h (in')

(in.)

(Max.

AP Rate Temp.

Width (Psi)

(gpm)

('F)

)

(in.)

135'-315' O.900 0.894 0.893 8900 0.015 Same as above for 8900 psi bladder pressure with 0.15" offset 2005 1.48 615'F 2560 1.94 615'F 2335 Adj. to Ref.

AP @

2560 615'F 2335 R.T.

adj. to 615' 2560 Note 2 Notes: 1. Diameters given are approximately the values at the two edges of the TSP. Diameters greater than the initial 0.876" diameter indicate bulging of the tube at the edges of the TSP as a result of the tube pressurization.

2. Crack lengths from dye penetrant measurements prior to bladder pres-surization.

3. Crack lengths from toolmaker's microscope. Minimum measurable TW crack opening -0.001".

s ape \\cpri\\trNenk2 wp6. June 20,1995

e References 1.

. M. Lynch letter to D. Farrar dated March 24,1995, transmitting the Nuclear Regulatory Commission comments on Commonwealth Edison's Company Proposed Test Program for Steam Generator Tube Indications Restricted from Burst.

2.

D. Saccomando letter to NRC dated March 20,1995, transmitting Information Regarding Questions Pertaining to Increased Interim Plugging Criteria.

3.

D. Saccomando letter to the Nuclear Regulatory Commission dated March 15, 1995, transmitting Commonwealth Edison's response to the Nuclear Regulatory Commission Concerns as Documented in Meeting Summary dated March 14, 1995.

4.

M. Lynch letter to D. Farrar dated March 14,1995, transmitting a Meeting Summary from the February 23,1995, NRC/ Comed Meeting.

5.

WCAP-14273 (Proprietary), " Technical Support for Alternate Plugging Criteria with Tube Expansion at Tube Support Plate Intersections for Braidwood-1 and Byron-1 Model D-4 Steam Generators, " Westinghouse Electric Corporation, February 1995.

6.

D. Saccomando letter to NRC dated April 3,1995, transmitting Comed's proposed test program for IRB testing.

7.

D. Saccomando letter to NRC dated May 25,1995, transmitting information regarding leak rate test program.

h l

i 1

It :nla : Bybwd.St een/IPC7esT;27

1 1

Leak Rate Methodology I

i i

k:nla kytwd:Steen/IPCTesT,2$

l o

l COMPARISON OF FREESPAN AND IRB LEAK RATES l

The information contained in this Attachment supersedes information contained in l

Sections 9.7 and 9.8 of WCAP-14273, Reference 1. Information has been previously presented to the NRC (Comed /NRC meetings on April 11,1995 and May 9,1995)

I on the effect ofincluding indication restricted from burst (IRB) leak rates in the 95% confidence estimate for the total leak rate to be expected from TSP indications in a SG experiencing a postulated SLB event at the end of the operating cycle. The conclusion of comparisons of simulations with and without consideration ofIRBs is that the expected total leak rates at a 95% confidence level are very similar. The effect of IRBs with a 3.0 volts repair limit was also evaluated until the time of SG I

replacement (Braidwood 1 in the Fall of 1998, and Byron 1 in the Spring of 1999),

and the results indicate a trend of similar total leak rates, i.e., the inclusion of consideration ofIRBs has a small effect on the predicted total leak rate. Although this may seem to be inconsistent with the concept of an IRB, it is not. The expla-nation for this phenomenon is discussed in the following paragraphs.

Figure 1 illustrates the correlations of the median and average (adjusted for the pol) leak rates to indication bobbin amplitudes for 3/4" diameter Alloy 600 SG l

tubes in Westinghouse type SGs. Also illustrated is a plot of the regression i

equation one-sided prediction bound leak rate at a prediction level equal to the probability that the indication does not experience a burst, i.e., one minus the probability of burst (PoB), as a function of the bobbin amplitude. Finally, the limiting fixed, i.e., independent of voltage, leak rate for IRBs, as supported by the results of the current leak testing program, is also illustrated (the heavy horizontal I

line at 10671ph). A comparison of the latter two curves indicatds that it is more likely to simulate higher leak rates for high voltage indications from the leak rate to volta correlation than it is by using the IRB leak rate in conjunction with the 1

I probability of burst. Also, from Figure 1, the average free span leak rate from a 22 volt indication is equal to the bounding IRB leak rate.

The probability of burst used in this comparison is deterministically estimated as described in Reference 1, i.e., the statistic P -P g

gu (1) t su -

OP is assumed to be distributed as a Student's t distribution, where Pg is the estimated burst pressure from the regression of burst pressure on bobbin amplitude, P w is 3

the steam line break pressure (2560 psi), and oP is the standard error of the predicted burst pressure obtained from the standard error of the regression and the standard deviation of the material properties. The probability of burst is then S.\\ APC\\CcE95\\ APDXV.WP5 1

06/20/95

- obtained as PoB - Pr{t 2 tyt,ldof}.

(2) where dofis the degrees for freedom from the regression of the burst pressure on the bobbin amplitude. The expected leak rate from each potential IRB, with the predicted leak. rate for an IRB being Qo, is, Q,,,= pod-Qo, (Expected)

(3) where Qo is estimated for IRBs from the leak rate testing. The expected leak rate from a potential IRB, which includes the effect of PoB, is considered to be conser-vative, even though it is based on a deterministic estimate rather than on the l

Monte Carlo simuletions, per the discussion in Section 9.4 of Reference 1.

I i

For a specific indication amplitude, the predicted and expected leak rates from a j

burst tube can be compared to the corresponding leak rates from the free span I

correlation at the same probability level. Using the degrees of freedom, v, from the leak rate as a function of volts correlation, a (1-PoB) 100 % prediction bound on the leak rate from an indication that leaks is obtained as, Q,.,,3 - Q,. 10 '- ",

(4) where Q, is the predicted leak rate from the regression equation, and o, is the effective standard error of the regression (adjusted for the standard error of the coefficients of the regression). The predicted (1-PoB) 100% leak rate from the indication would be pol-Q3.p,3, and the expected, or average, leak rate from each indication of a large number ofindications at the same voltage level is then found as, Qrs - PoB pol - Q3.p,3,

@ Ped W

l where pol is the probability ofleak of the indication. For example, the probability of burst of a 6 volt indication is conservatively estimated as 0.0027. For a constant predicted IRB leak rate, Qo, of 10671ph (4.7 gpm), the expected leak rate from the indication is 2.851ph. The probability that the tube does not burst is 0.9973. A 99.73% prediction bound on the leak rate from a single indication that leaks is y

949 lph. The probability ofleak of the same indication is 0.822, thus the predicted l

leak rate from the indication is 780 lph. Since the likelihood of experiencing a leak I

rate greater than or equal to this value is 0.0027, the expected leak rate from the indication is estimated as 2.081ph. Table 1 and Table 2 list the predicted and l

expected IRB leak rates, Qiy,, and the expected correlation leak rates, Qry, for s.urcsecenurnx.r.wes 2

ossom

s.

sev:rnl indic tion bobbin emplitud:s. Figura 2 illustrates a comparison of the correlation expected leak rate as a function of the IRB expected leak rate for'a range of bobbin amplitudes from 4.75 volts to approximately 63 volts. From Table 1, the predicted leak rate from a 7.8 volt IRB is 10671ph, while, from Table 2, the expected leak rate from a 7.8 volt indication is 7.81ph. The expected freespan leak rate at the same probability of occurrence as a burst,0.0073, is also 7.81ph. Thus, for a 7.8 volt indication, a predicted leak rate of 10671ph is as likely to occur as a result of predicting the leak rate from the correlation ofleak rate to bobbin amplitude as it is from predicting the leak rate based on the likelihood of experiencing an IRB.

It could be argued, if the probability of predicting large leak rates from single indications using the free span correlation is approximately the same as the probability of predicting large leak rates from IRBs, then the simulation of many such indications should lead to an approximate doubling of the expected leak rate.

Hence, it would be expected that simulation leak rates based on including special provisions for IRBs would be significantly higher than simulation rates without those provisions. However, recall that in the above comparison the PoB is being overestimated, perhaps by an order of magnitude at the lower voltage. Thus, the probability of not bursting is being underestimated, hence the (1-PoB) 100 %

prediction bound from the correlation leak rate is also being underestimated. This means that a true comparison curve a la Figure 2 would be shifted to the left if also plotted on Figure 2. Hence the likelihood of predicting large leak rates based on the free span correlation is greater than the likelihood of predicting a large leak rate from an IRB. This reduces the effect of the contribution ofleak rates from IRBs on the total leak rate. The Monte Carlo simulations have demonstrated this effect to be on the order of ~20% for the distribution ofindications in the Braidwood 1 and Byron 1 SGs. For the application ofIPC, this difference is not significant when comparing the predicted totalleak rate at 95% confidence to the allowable leak rate based on radiological considerations. The implication of the comparison of the two curves is also that as the median amplitude of the population ofindications increases, the absolute magnitude of the difference would be expected to be about the same, thus the relative magnitude of the difference would be expected to diminish. The trend of results from simulation projections supports this supposition. Hence, the inclusion of special provisions for the simulation of J

leak rates from IRBs is not necessary.

In conclusion, end of cycle 95% confidence bound total leak rates can be satisfac-torily predicted using the free span leak rate correlation to the bobbin amplitude of the indications for the Braidwood 1 and Byron 1 SGs.

It is to be noted that this conclusion could be affected if the burst pressure as a fhnetion of volts and/or the leak rate as a function of volts correlation (s) changes significantly with regard to the regression curve parameters or the standard error of the regression. The most significant reason why the free span leak rate predic-SWGcCE95\\APDX.F.WP5 3

om w9s j

')

i

- tions can exceed the IRB leak rate predictions is probably the magnitude of the standard error of the common logarithm of the leak rate about the regression line.

r Moreover, this evaluation would have to be revisited if any significant changes in i

the correlations' parameters changed.

~

l References 1

1.

WCAP-14273 (Proprietary), " Technical Support for Alternate Plugging Criteria

)

with Tube Expansion at Tube Support Plate Intersections for Braidwood-1 and j

Byron-1 Model D4 Steam Generators," Westinghouse Electric Corporation, i

February,1995.

)

i l

J l

S.\\APC\\CCE95\\APDX-F.WPs 4

on2oss

]

i

TABLE 1: COMPARISON OF PREDICTED LEAK HATE FROM IRBS AND FREE SPAN ODSCC INDICATIONS Bobbin P

PoB Qma pol Q,.,,,

Qrs 3

Volts (ksi)

(Iph)

(Eph)

(lph) 4.75 5.453 0.0010 1067 0.663 802 531 6.0 5.150 0.0027 1067 0.822 949 780 7.0 4.951 0.0049 1067 0.890 1065 948 7.8 4.811 0.0073 1067 0.923 1157 1970 10.0 4.488 0.0175 1067 0.968 1412 1367 TABLE 2: COMPARISON OF EXPECTED LEAK RATE FROM IRBS AND FREE SPAN ODSCC INDICATIONS Bobbin P

PoB Qma pol Q,.,,a Qrg s

Volts (ksi)

(lph)

(Iph)

(lph) l 4.75 1.10 0.55 6.0 2.85 2.08 Values are the Values are the 7.0 same as 5.20 same as 4.61 7*8 7*79 7*79 Table 1 Table 1 10.0 18.7 23.9 S \\APC\\CCE95\\APDX F.WP5 5

oscoms

p

..a Figure 1: SLB Leak Rate vs. Bobbin Amplitude 3/4" x 0.00" Alloy 600 SG Tubes @ 650*F, AP = 2560 psi l

20000.

,g, s-*- Y i

?

r 1000-

. =.

7

,-,y y-

,r_..

,. c'

, /-

h 100 5.

__._..-4_

y

/

g

~

/

/

e j_

10.

s' 1.

g

_j-4 EPRI/NRC Database (05/95) j Regmssion Fit (Median)

. ~/

--- Average leak Rate

• Pot i

IRB Fixed Lite l

0.1

-[

- - Leak Rate @ (1-PoB)

• pol 0.01 1

10 100 Bobbin Amplittide (Volts) i t

Figure 2: Correlation Leak Rate at (1-PoB) Prediction vs.

l the Fixed IRB Leak Rate Times the Probability of Burst 10000.

-g----.-

-. j. 2.

l 4

s..7 L'

f 8.

f

/

=

@ 1000.

y

---/

~

,5

\\

3'I

. 4

$0vi a

Af

100, a

- ~_

-fg g

fy~

/

~

3

\\

r j

10.

m_g

..q

- a_a.

J j

Td-8 vi c

.','/

\\

n i

1.

. $gN/g-f- -

-.y" ---.-..-,.

h 3,t l Note: The correlation leak rate -555

O 7

4.75 vl has been adjusted for the pol, :--::

b_

-J

! and for the PoB.

L' l

I!il l l litilil.

I i i 0.1 0.1 1.

10.

100.

1000.

10000.

PoB Times the Fixed IRB Leak Rate Oph) l S.\\APC\\CCE95\\APDX-F.WP5 6

0640S5 r