Calvert Cliffs Nuclear Power Plant 1650 Calvert Cliffs Parkway Lusby, Maryland 20657

A Member of the Constellation Energy Group

December 1, 1999

U. S. Nuclear Regulatory Commission Washington, DC 20555

ATTENTION:

SUBJECT:

REFERENCES:

Document Control Desk

Calvert Cliffs Nuclear Power Plant Unit Nos. 1 & 2; Docket Nos. 50-317 & 50-318 Relief Request to Use ASME Section III Code Case N-20-4 and Section IX Code Cases 2142-1 and 2143-1 as an Alternative to ASME Code Requirements

(a) Letter from Mr. J. N. Hannon (NRC) to Mr. W. T. Cottle (South Texas Project), dated December 15, 1998, Relief Request to Use ASME Code

Cases 2142-1 and 2143-1 for Replacement Steam Generators, South Texas Project, Units 1 and 2 (TAC Nos. MA2250 and MA225 1)

(b) Letter from Mr. R. L. Emch, Jr. (NRC) to Mr. W. R. McCollum, Jr. (Duke Energy Corporation), dated September 10, 1999, Oconee Nuclear

Station, Units 1, 2, and 3 Re: Use of Alternative Weld Materials in Replacement Steam Generators (TAC Nos. MA6209, MA6210, and MA621 1)

Pursuant to 10 CFR 50.5 5a(a)(3)(i), Baltimore Gas and Electric Company hereby proposes alternatives to the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (Code)

requirements in connection with the fabrication and installation of replacement steam generators for

Calvert Cliffs Nuclear Power Plant, Units 1 and 2. Paragraph 50.55a(a)(3)(i) allows the use of

alternatives to the Code requirements, which provide an acceptable level of quality and safety, when

authorized by the Director of the Office of Nuclear Reactor Regulation. The Calvert Cliffs replacement steam generators are being designed and fabricated under the 1989 Edition, no Addenda, of the ASME

Code. Installation is planned for Unit 1 in spring 2002, and for Unit 2 in spring 2003. The details of our

relief requests and their justifications are provided below.

RELIEF REQUEST TO USE ASME, SECTION HI CODE CASE N-20-4

The Calvert Cliffs replacement steam generators utilize Alloy 690 tubing material. This nickel

chromium-iron alloy material has been approved by ASME through Code Case N-20-4 (Attachment 1).

It is designated UNS N06690 and complies with ASME Section II SB-163, ASME Section III NB-2000.

?- L prxL 0§GCOý A~k'

Document Control Desk December 1, 1999 Page 2

Use of this tubing material for fabrication of replacement steam generators has been previously approved by ASME through Code Case N-20-3 (Attachment 2). Code Case N-20-3 is listed as an acceptable Code Case to the NRC staff for application in the construction of components for light-water-cooled nuclear power plants in Regulatory Guide 1.85, Revision 31 (May 1999), "Materials Code Case Acceptability ASME Section III, Division 1."

Code Case N-20-4 corrected values for the yield strength and ultimate strength previously reported in Code Case N-20-3. At the time of issuance of Code Case N-20-3, industry experience was primarily limited to Alloy 600. Because of the similarity of Alloys 690 and 600 it was assumed that properties would be similar. With growth of industry experience with Alloy 690, it was determined that a consistent difference exists in material properties between Alloy 600 and Alloy 690. The revised yield strength for both Alloy 690 and Alloy 600 decreases with temperature, with a slightly higher rate for Alloy 690 than for Alloy 600. The tensile strength for Alloy 600 remained unchanged. However, the revised tensile strength for Alloy 690 shows higher values at lower temperature and lower values at higher temperatures than was previously reported in Code Case N-20-3. Use of Code Case N-20-4 is considered conservative since relevant design analyses will be performed using accurate, rather than the incorrect (mostly higher), values for material strength. Therefore, use of Code Case N-20-4 provides an acceptable level of quality and safety.

RELIEF REQUEST TO USE ASME, SECTION IX CODE CASES 2142-1 AND 2143-1

As mentioned above, Alloy 690 is used in the fabrication of the Calvert Cliffs replacement steam generators. Weld filler materials that are similar to Alloy 690 are necessary in the fabrication and installation of the replacement steam generators. Such materials have been approved by ASME through Code Cases 2142-1 and 2143-1 and are designated as UNS N06052 and UNS W86152, respectively. The NRC has previously approved the use of these code cases for similar application for South Texas Project by letter dated December 15, 1998 (Reference a), and for Oconee by letter dated September 10, 1999 (Reference b).

American Society of Mechanical Engineers first approved Code Cases 2142-1 and 2143-1 on June 5, 1995, and reaffirmed their use on July 22, 1998. The Code Cases classified the weld materials as F-No. 43 for both weld procedure and performance qualification purposes. UNS W86152 is the matching shielded metal arc welding electrode for Alloy 690 and UNS N06052 is the companion bare filler metal. These weld materials have been shown in an Electric Power Research Institute study to provide superior corrosion resistant weldments for application with Alloy 690 material. Therefore, use of Code Cases 2142-1 and 2143-1 provides an acceptable level of quality and safety.

SAFETY COMMITTEE REVIEW

The proposed relief request has been reviewed by our Plant Operations and Safety Review Committee, and they have concluded that the proposed alternative provides an acceptable level of quality and safety.

SCHEDULE

To support our current fabrication and installation schedule, we request that the NRC review and approve our proposed alternative by March 30, 2000.

Document Control Desk December 1, 1999 Page 3

Should you have questions regarding this matter, we will be pleased to discuss them with you.

Very truly yours,

CHC/GT/dlm

Attachments: (1) ASME Code Case N-20-4 (2) ASME Code Case N-20-3

cc: R. S. Fleishman, Esquire J. E. Silberg, Esquire S. R. Peterson, NRC A. W. Dromerick, NRC

H. J. Miller, NRC Resident Inspector, NRC R. I. McLean, DNR J. H. Walter, PSC

ATTACHMENT (1)

ASME Code Case N-20-4

Baltimore Gas & Electric Company Docket Nos. 50-317 and 50-318

December 1, 1999

CASE

N-20-4

CASES OF ASME BOILER AND PRESSURE VESSEL CODE,

Approval aato: F.bnacy 26, 1999

See Numeric Index for expiration and any reaffirmatlon dates.

Case N-20-4 SB-163, Cold Worked UNS NOM8OO; and SB-163

UNS N06600, UNS N06690, and UNS N080 to Supplementary Requirements S2 of SB-163

Section 11 Division 1, Class I

Inquiry: May SB-163 Cold Worked UNS N08800 and SB-163 UNS N06600, UNS N06690, and UNS

N08800 meeting the requirements of Supplementary Requirement S2 of SB-163, be used in the costruc

tion of Class I components in accordance with Section

IH Division I?

Reply: It is the opinion of the Committee that SB

163 Cold Worked UNS N08800; and SB-163 UNS N06600, UNS N06690, and UNS N08800 meeting the

requimments of Supplementary Requirement S2 of SB-163, may be used in the construction of Class 1

components in accordance with Section I Division

1, providing the following additional req"uirments are met.

(a) The design stress intensity values shall be those listed in Table 1.

(b) The yield strength values shall be that listed in Table I

(c) The tensile strength values shall be that listed in Table 3.

(d) For external pressure, the required thickness of the tubing shall be de=nined in accordance with pam. NB-3133, using Fig. 1 for alloys UNS N06600 and UNS N06690 and Fig. 2 for alloy UNS N08800.

(e) Welding procedure and performance qualifications shall be in accordance with Section IX. Welding of cold-worked alloy UNS N08800 shall be limited to tube-to-tube sheet welds.

(f) This Case number shall be shown in the documentation and marking of the material and in the Certificate Holders Data Report.

TABLE I DESIGN STRESS INTENSITY VALUES, S,, ksi [Note (1)]

For Material Temperature

Not Exceeding IF UNS N06600 UNS N06690 UNS N08800 CW UNS N08800

100 26.7 26.7 25.0 27.7

200 26.7 26.7 25.0 27.7

300 26.7 26.7 25.0 27.7

400 26.7 26.7 25.0 27.5

500 26.7 26.7 25.0 26.9

600 26.7 26.7 24.9 26.7

650 26.7 26.7 24.8 26.6

700 26.7 26.6 24.8 ...

750 26.7 26.5 24.7 ...

800 26.7 26.4 24.6

NOTE: (1) Due to the relatively low yield strength of these materials, these higher stress values wort established at temperatures where the short time

tensile properties govern to permit the use of these alloys where slightly greater deformation Is acceptable. The stress values in this range

exceed 66ý4% but do not exceed 90% of the yield strength at temperature. Use of these stresses may result in dimensional changes due

to permanent strain. These stress values are not recommended for the flanges of gasketed joirrts or other applications where silght amounts

of distortion can cause leakage or malfuncton. Table Y-2 of Section II, Part D, lists multiplying factors that, when applied to the yield

strength values shown in Table 2, will give allowable stress values that will result In lower levels of permanent strain.

SUPP. 4 - NC7

CASE (continued)

N-20-4 CASES OF ASMNE BOILER AND PRESSURE VESSEL CODE

TABLE 2 YIELD STRENGTH VALUES [Note (1)3

For Material

Temperature

Not Exceeding OF UNS N06600 UNS N06690 UNS N08800 CW UNS N08800

100 40.0 40.0 40.0 47.0

200 36.6 36.2 37.0 43.4

300 35.6 34.1 35.5 41.7

400 35.1 32.7 34.4 40.4

500 34.7 31.9 33.5 39.5

600 34.2 31.5 32.6 38.7

650 33.9 31.5 32.2 38.7

700 33.6 31.5 31.8

750 33.2 31.5 31.4 ...

800 32.8 31.5 31.0

NOTE:

(1) The tabulated values of yield strength are those that the Committee believes are suitable for use in design calculations. At temperatures

above room temperature, the yield strength values correspond to the yield strength trend curve adjusted to the minimum specified room

temperature yield strength. The yield strength values do not correspond exactly to minimum as this term Is applied to a statistical treatment

of a homogeneous set of data.

Neither the ASME Material Specifications nor the rules of Section III require elevated temperature testing for yield strengths of production

material for use in Code components. It is not intended that results of such tests, if performed, be compared with these tabulated yield

strength values for ASME Code acceptancetrejection purposes for materials. (f some elevated temperature test results on production material

appear lower than the tabulated values by a large amount (more than the typical variability of material and suggesting the possibility of

some error), further Investigation by retest or other means should be considered.

TABLE 3 TENSILE STRENGTH VALUES (Note (1)]

For Material Temperature

Not Exceeding OF UNS N06600 UNS N06690 UNS N08800 CW UNS N08800

100 80.0 85.0 75.0 83.0 200 80.0 85.0 75.0 83.0

300 80.0 84.0 75.0 83.0

400 80.0 82.0 75.0 82.5

500 80.0 80.6 74.g 80.7

600 80.0 80.2 74.7 60.0

650 80.0 80.0 74.5 79.9

700 80.0 79.8 74.3 ...

750 00.0 79,6 74.1 ...

800 80.0 79.3 73.8

NOTE:

(1) The tabulated values of yield strength are those that the Committee believes are suitable for use in design calculations. At temperatures

above room temperature, the yield strength values correspond to the yield strength trend curve adjusted to the minimum specified room

temperature yield strength. The yield strength values do not correspond exactly to minimum as this term is applied to a statistical treatment

of a homogeneous see of data.

Neither the ASM E Material Specifications nor the rules of Section III require elevated temperature testing for yield strengths of production

material for use in Code components. It is not intended that results of such tests, If performed, be compared with these tabulated yield

strength values for ASME Code acceptance/rejection purposes for materials. If some elevated temperature test results on production material

appear lower than the tabulated values by a large amount (more than the typical variability of material and suggesting the possibility of

some error), further Investigation by retest or other means should be considered.

SUPP. 4 - NC 8

CASE (continued)

N-20-4CASES OF ASME BOTLERP AND PRESSURE VESSEL CODE

TABLE 4 TABULAR VALUES FOR FIG. 3

Temperature 'F

100

300

Tersile Strength Values

A

0.68-03 10,000 0.48-03 14,100 0.40-02 18,400 0.10-01 21,000 0.20-01 22,400 0.30-01 23,000

0.75-03 10,000 0.11-02 14,300 0.20-02 14,800 0.40-02 16,300 0.10-01 18,200 0.20-01 19,500 0.30-01 20,100

0.75-03 10,000 0.10-02 13,800 0.20-02 14,400 0.40-02 15,500 0.10-01 17,100 0.20-01 17,400 0.25-01 17,700

0.78-03 10,000 0.10-02 12,300 0.20-02 13,200 0.40-02 14,300 0.10-01 15,900 0.20-01 17,200 0.30-01 18,000

500

700

SUPP. 4 - NC9

CASE (continued)

N-20-4CASES OF ASME BOILER AND PRESSURE VESSEL CODE

, • up to 100-F

_.__.ill FT 40 F-I i

" ' t ol ' o

= =r31.6X1 -' ''

i ! E =30.0 X oe Ii

, : ,"E 26.6 x lo0 .Z1

2 3 4 S 6 7 8g 2 3 4 5 6 7 89 2 3 4 5 6 78 S 2 3 4 S6 789

.0001 .001

FACTOR A

.01 .1

FIG. 1 CHART FOR DETERMINING SHELL THICKNESS OF CYLINDRICAL AND SPHERICAL EXTERNAL PRESSURE SB-163 UNS N06600 and UNS N06690

VESSELS UNDER

-I - -- •

7. .7 7 8 2 , ,8 --•- --k•/~I ....A Ifl _ *, ,,'I Ml , ' ' t i l

.00001 .0001 .001

FACTOR A

.01

20,000 16,000

16,000

14,000

12.000

10,00o

9,000

8.000

7,000

6.000

5,000

4,000

34500

3.000

2,500

2.000

.I

FIG. 2 CHART FOR DETERMINING SHELL THICKNESS OF CYLINDRICAL AND SPHERICAL VESSELS UNDER EXTERNAL PRESSURE WHEN CONSTRUCTED OF SS-163 UNS N08800 (ANNEALED)

SUPP. 4 - NC

40,000

35.000

30.000

25,000

20.000

18,000

16.000

14,000

12.000

10,000

9,000

8,000

.00001

0 I-0

U_

I ,',JUU

6.000

5.000

4.000

co

0 F0

L.

10

CASE (continued)

N-20-4CASES OF ASME BOILER AND PRESSURE VESSEL CODE

I T

\-T I I •

i~~~ ~ 1 l IFI ...

E 26,6 , l | fi

2 3 4 5 6 7 89 2 3 a 567 9 2 S 6 769 2 3 4. $ 6 7 as

0.0001 0.001

FACTOR A001

50,000

40.000

3S,000

30.000

25,000

20.000

18.000

16.000

14.000

12,000

10.000

9.000

8.000

7,000

6.000

5.000

0

U.

o0

FIG. 3 CHART FOR DETERMINING SHELL THICKNESS OF CYLINDRICAL AND SPHERICAL VESSELS UNDER EXTERNAL PRESSURE WHEN CONSTRUCTED OF SB-163 COLD WORKED UNS N08800

SUPP. 4 - NC

0.0U001

10.1

ATTACHMENT (2)

ASME Code Case N-20-3

Baltimore Gas & Electric Company Docket Nos. 50-317 and 50-318

December 1, 1999

CASE

.N-20-3CASES OF ASME BOILER AND PRESSURE VESSEL CODE

Approvae Date: November 30. 1968

See Numeric Index for expiration and any reafflrmatlon dates.

Case N.20.3 SB-163 Nickel-Chromium-Irort Tubing (Alloys 600 and 690) and Nickel-Iron-Chromium Alloy 800 at a Specified Mlnimum Yield Strength of 40.0 ksl and Cold Worked Alloy 800 at a Yield Strength of 47.0 ksi Section III, Division 1, Cla I

Inquiry: May nickel-chromium-irorn and nickeliron-chromium alloy seamless condenser and heat cxchangcr tubing meeting the size range and specified properties as listed in Table I and otherwise meeting the requirements of SB-163 for Alloy 600 and 800 and the requirements of SB-163 for Alloy 690 except for the chemistry (Alloy 690 chemistry is listed in Table 3), be used in the construction of Class I components in accordance with Section III, Division 17

chromium Alloy 800 seamless oondenser and heat exchanger tubing meeting the requirements- given on the Inquiry may be used in the construction of Class I components in accordance with Section f[I, Division 1, provided the tensile1 yield strength, and design stress intensity values as listed in Tables I, 2 and 4. respectively are used. In addition to the marking requirements of SB-163, the tubing shall be identified with this Case number. For external pressure the required thickness of the tubing shall be determined in accordance with Par. NB-3133 using Fig. I for Alloys 600 and 690 and using Fig. 2 for Alloy 800. Welding procodure and p^-formanoe qualifications shall be in accordance with Section IX Separate welding procedure and performance qualilications arc required for Alloy 690. Welding of CW Alloy 800 material shall be limited to tube-to-tube sheet welds.

Reply: It is the opinion of the Committee that nickel-chromium-iron Alloys 600 and 690 and nickel-iron

TABLE 1

Specified Mechanical Properties and Size Ranges

Spec. Yiekld Stmngth Min, Tube Size Range, In. TeM.(e ScS1 (0.2% Offset) Etongation Wall

Stmzf kW Mt. Mmx. 2 In., % 0.0. Thickness

Alloys 60O and 690 80 40 65 30 X, to Up to o.100 Alloy 800 80 40 65 30 X/ to • Up to 0.100 CW Alloy 800 83 47 70 30 Y to ' Up to 0.100

TABLE 2

Design Stress Intensity Values, S.. lsi, for Materia( Temperature Hot Excoding, TF

100 200 300 400 500 600 650 700 750 800

Alloys 600 and 690 Alloy 600 CW Alloy 800

26.6 26.6 26.6 26.6 26.6 26.6 26.6 26.6 26.6 26.6 26.0 25.7 25.7 25.7 27.0 27.0 27.8 27.5 26.9 26.6 26.6

26.6 26.6 26.6 25.7 25.7 25.7

7

* CASE (continued)

N-20-3CASES OF ASME BOILER AND PRESSURE VESSEL CODE

TABLE3

Cemlvst - Alloy 690 Per'ent

M10 May

Cr 27 31 Fe 7 11 C ... 0.05 s 0.50 ma ... 0.50 S ... 0.015 Co ... 0.10 Cu ... 0.50 NI 58.0 ...

TABLE 4

yie(d Streigth Values - Alloys 600, 690 and 800

Y. S. Value Cw

Temp. , Altoys 600 & 690 Alloy 800 Alloy 800

100 40.0 40.0 47.0 200 38.2 36.8 42.5 300 37.3 34.6 40.6 400 36.3 33.0 39.2 500 . 35.7 31.8 38.5 600 35.3 31.1 37.7 650 35.2 30.9 37.3 700 35.0 30.6 ... 750 .4.9 30.3 ... 800 34.8 30.0 ...

8

I.-

CASE (continued)

N-20-3CASES OF ASME IBOLLER AND PRESSURE VESSEL OODE

6 678Q .01

40.000 35.000

30,000

2S,000

20.000 18,000

1C.000 14.000

1Z000

l9.000

7.000

6.000

6.000

4,000

.1

FACTOR A

FIG. 1 CHART FOR DETERMINING SHELL THICKNESS OF CYUNDRICAL AND SPHERICAL VESSELS UNDER EXTERNAL PRESSURE

Nicke.-Chromium-tron Ailoys 600 and 690 SB-163, .S min = 40,000 psi

4 6 6781 .001

0718 .01

20.000 18,000

11G.030

14.000

12.0W0

10,000

0.000

5.000

S.000

3.600

3.000

7.50

.1

FACTOA A

FIG. 2 CHART FOR DETERMINING SHELL THICKNESS OF CYLINDRICAL AND SPHERICAL VESSELS UNDER EXTER

NAL PRESSURE WHEN CONSTRUCTED OF NICKEL-IRON-CHROMIUM ALLOY 800 (ANNEALED)

9

67689 =001

I

CASE (continued)

N-20-3 CASES OF ASME BOILER AND PRESSURE VESSEL CODE

TABLE 5 TUBULAR VALUES FOR FIG. 3

B, B, Temp., "F A psi Temp-, F A psi

100 0.68-03 10,000 500 0.75-03 10,000 048-0. 3 14.100 0.10-02 13,800 0.40-02 18,400 0.20-02 14,400 0.10-01 21,000 0.40-02 15,500 020-01- 22.400 0.10-01 17,108 0.30-01 23,000 0.20-01 17,00

0.25-01 17,700

300 0.75-03 10,000 700 0.78-03 10,000 0.11-02 14,300 0.10-02 12,300 0.20-02 14,800 0.20-02 13,200 0.40-02 16,300 0.40-02 14,300 0.10-01 18,200 0.10-01 15,900 0.20-01 19,500 0.20-01 17,200 0.30-01 20,100 0.30-01 18,000

2 3 4 667a0

0.0001

2 3 4 6 6789

0.001

2 0 4 66780

0.01

60000

40.000

35.000

30.000

25.000

20,000

18.000

16.000

14.000

12A00

¶ 0,000

il.000

8.000

7.000

6.000

G.0002 3 4 G 6 789

0.1

FACTOR A

FIG. 3 CHART FOR DETERMINING SHELL THICKNESS OF CYLINDRICAL AND SPHERICAL VESSELS UNDER EXTERNAL PRESSURE WHEN CONSTRUCTED OF NICKEL-IRON-CHROM[UM ALLOY 80 (MODIFIED)

10

0.00001