ML20006G171

Safety Evaluation Concluding That pressure-temp Limits for RCS for Heatup,Cooldown,Leak Test & Criticality for 10 EFPY, Proposed in Re Generic Ltr 88-11,acceptable

ML20006G171
Person / Time
Site:	Grand Gulf
Issue date:	02/21/1990
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20006G126	List: ML20006G125 ML20006G171
References
GL-88-11, NUDOCS 9003050269
Download: ML20006G171 (5)

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ENCLOSURE SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION REf0NSE TO GENERIC-LETTER 88-11 SYSTEM ENEPGY RESOURCES. INC.

GRAND _ GULF HUCLEAR STATION,' UNIT 1 DOCKET h0. 50 N16 l

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1.0 INTRODUCTION

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In response to Generic Letter 88-11. "NRC Position on Radiation Embrittlenent of Reactor Vessel Materials and Its Effect on Plant Operations," System Energy.

Resources, Inc. (the licensee), requested permission to revise the pressure / tem-j perature (P/T) liaits in the Grand Gulf Nuclear Station, Unit.1, Technical 1

Specifications,. Section 3/4.4.6. The request was documented in letters from i

the licensee dated denuary 9,1989, February 28, 1989 and October 10, 1989.

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This revision also changes the effectiveness of the P/T limits from 32 to 10 d

l ef fective full power years (EFPY).

The proposed P/T limits were developed based on Section 1 of Regulatory Guide 1.99, Revision 2. (RG 1.99,. Rev. 2).

The

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proposed revision provides up-to-date P/T limits for the operation of the '

a reactor coolant system during heatup, cooldown, criticality, and hydrotest.

To evaluate the P/T limits, the staff used the following NRC regulations and guidance: ' Appendices G and H of 10 CFR Part 50; the ASTN Standards and the o

L ASME Coce, which are referenced in Appendices G and H; 10 CFR 50.36(c)(E); RG-

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1~.99, Rev. 2; Standard Review Plan (SRP) Section 5.3.2; and Generic Letter 88-11.

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Each licensee authorized to operate a nuclear power reactor is required by i

10 CFR 50.36 to provide Technical Sp(ecifications for the operation of theIn pa plant.

k operation be included in the Technical Specifications. The P/T limits are l

among the limiting conditions of operation in the Technical Specifications for all coninercial nuclear plants in t1e U.S.

Appendices G and H of 10 CFR Part 50 7

describe specific requirements for fracture toughness and reactor vessel material surveillance that must be considered in setting P/T limits.

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acceptable athod-for constructing the P/T limits is described in SRP Section 5.3.2.

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y Appendix G of 10 CFR Part 50 specifies fracture toughress and testing require-ments for-reactor vessel naterials in accordance with the ASME Code and, in particular, that the beltline reterials in tM surveillance capsules be. tested

-in accordance with Appendix H'of 10 CFR Part S0. Appendix H, in turn.. refers to ASTM Standards.

These tests define the extent of vessel entrittlenent at the time of capsule withdrawal in terms of the increase in reference tempera-ture.

Appendix G also reouires the licensee to predict the effects of neuttan-

. irradiation on vessel embrittlement by calculating the adjusted reference temperature (ART) and Charpy upper shelf energy (USE).

Generic Letter 88-11 requested that licensees and permittees use the methods in RG 1.99 Rev. 2, to-predict the effect of neutron irradiation on reactor vessel naterials.

This guide defines the ART as the sum of unirradiated reference tenperature, the increase in reference teniperature resulting from neutron irradiation, and a margin to account for uncertainties in the prediction nethod.

Appendix H of 10 CFR Part 50 requires the licensee to establish a surveillance program to periodically withdraw surveillance r.apsules from the reactor vessel. Appendix H refers to the ASTM Standards which, in turn, require that the capsules be installed in the vessel before startup and that the test specimens nede from plate, weld, and heat-affected-zone (HAZ) y contain materials of the reactor beltline.

2.0 EVALUATION The staf f evaluated the effect of neutron irradiation entrittlement on each beltline material in the Grand Gulf reactor vessel.

The amount of irradiation enbrittlenent was calculated in accordance with RG 1.99, Rev. 2.

The staff has determined that the material with the highest ART at 10 EFPY at 1/4T (T= reactor vessel beltline thickness) was the longitudinal weld 627260 with I

0.06% copper (Cu),1.08% nickel (Ni), and an initial RT f -30'F.

The material with the highest ART at 3/4T, however, was plaNtC2594-2 with 0.04%

Cu, 0.63% Ni, and an initial RT o f 0

• F.

ndt The licensee has not removed any surveillance capsules from the Grand Gulf L

reactor vessel.

The staff has ensured that all surveillance capsules L

contained Charpy impact specimens and tensile specimens made from base netal, L

weld metal', and HAZ metal.

For the limiting beltline material at 1/4T, longitudinal weld 627260, the staff calculated the ART to be 25.2*F at 10 EFPY.

For the limiting beltline material at 3/4T, longitudinal plate C2594-2, the staff calculated the ART to be 11.3'F at 10 EFPY. The staff used a neutron fluence of 6.5E17 n/cnf at 1/4T and 2.9E17 n/cm' at 3/4T.

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The licensee used the method in RG 1.99, Rev. 2, to calculate an ART of k

25.76*F at 10 EFPY at 1/4T for the same limiting weld metal.

The staff judges that a difference of 0.56*F between the licensee's ART of 25.76'F and the staff's ART of 25.2*F is acceptable.

Substituting the ART of 25.76*F into equations in SRP 5.3.2, the staff verified that the proposed P/T limits for l

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'.... heatup, cooldown, and hydrotest reet the beltline material requirenents' in Appendix G of 10 CFR Part 50.

In addition to beltline materials, Appendix G of 10 CFR Part 50 also imposes P/T limits based on the reference temperature for the reactor vessel closure flange materials.

Section IV.2 of Appendix G states that when the pressure

. exceeds 20% of the preservice -system hydrostatic test pressure, the tenperature of the closure flange regions highly stressed by the bolt preload must exceed the reference temperature of the material in those regions by at least 120*F for normal operation and by 90*F for hydrostatic pressure tests and leak tests.

Paragraph IV. A.3 of-Appendix G states "an exception may be nade for boiling water reactor vessels when water level is within the normal range' for power operation and the pressure is less than 20 percent of the pre-service system hydrostatic test pressure.

In this case the minimm permissible temperature is 60*F (33*C) above the reference tenperature of the closure flange regions that I

are highly stressed by the bolt preload."

Based on the flange reference-

-i temperature of -30*F, the staff has determined that the proposed P/T limits satisfy Sectico IV.2 of Appendix G.

Section IV.0 of Appendix G requires that the predicted Charpy USE at end of life be above 50 ft-lb.

The material with the lowest initial USE is the girth weld with an initial USE of 79 ft-lb.

Using the nethod in RG 1.99, Rev. 2, l

the predicted Charpy USE of the girth weld natal at the end of life will be j

approximately 68 ft-lb.

This is greater than 50 ft-lb and, therefore, is acceptab le.

3.0 CONCLUSION

The staff concludes that the P/T limits proposed in the February 28, 1989 submittal for the reactor coolant system for heatup, cooldown, leak test, and criticality are valid through 10 EFPY because the limits conform to tlw l

requirenents of Appendices G and H of 10 CFR Part 50. 'The licensee's submittal also satisfies Generic Letter 88-11 because the licensee used the nethod in RG 1.99, Rev. 2 to calculate the ART.

Hence, the proposed P/T limits may' be incorporated into the Grand Gulf 1 Technical Specifications.

4.0 REFERENCES

L 1.

Regulatory Guide 1.99, Radiation Embrittlerent of Reactor Vessel Materials, Revision 2, May 1988 2.

NUREG-0800, Standard Review Plan, Section 5.3.2, Pressure-Temperature Limits 3.

Grand Gulf Nuclear Station, Final Safety Analysis Report (NUREG 0831) l 4.

Grand Gulf Unit 1, Technical Specifications (NUREG 0934) 5.

January 9,1989, Letter from J. G. Cesare, Jr., (SER) to USNRC Document Control Lesk,

Subject:

Response to Generic Letter 88-11

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February 28,.1989,- Letter from T. H. Cloninger (SER) to UShRC Cocument Contrvl. Desk,

Subject:

Response to Generic Letter 88-11, Updated '

'l Information-a

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October 13 19 89, Lette.r from W. T. Cottle (SER) to USNRC Document 1

~ Control Desk,

Subject:

Response to Request for Additional Information-1 Regarding Generic Letter 88-11.

Principal Contributor:

J. Tsao Date:. February 21, 1990 g

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l-Mr. W. T. Cottle System Energy Resources, Inc.

Grand Golf Nuclear Station (GGNS) cc:

.Mr. T. H. Cloninger Mr. C. R. Hotchinson Vice President, Aclear Engineering GGNS General Manager

& Sopport System Energy Resoorces, Inc.

System Energy Resources, Inc.

P. O. Box 756 P. 0._ Box 31995 Port Gibson, Mississippi 39150 Jackson, Mississippi 39266 Robert B. McGehee, Esquire The Honordble William J.- Goste, Jr.

Wise, Carter, Chiid, and Attorney General Ca raway Department of Justice P. O. Box 651 State of Lo isiana Jackson, Mississippi 39105 P. O. Box 94005 Baton Rouge, LA 70804-9005 Nicholas S. Reynolds, Esquire Bishop, Cook, Porcell Alton B. Cobb, M.D.

and Reynolds State Health Officer 1400 L Street, N.W. - 12th Floor State Board of Health Washington, D.C.

20005-3502 P. O. Box 1700 Jackson, Mississippi 39205 Mr. Ralph T. Lally Manager of Quality Assurance Entergy Services, Inc.

Office of the Governor P. O. Box 31995 State of Mississippi Jackson, Mississippi 39286 Jackson, Mississippi 39201 Mr. Jack McMillan, Director.

President,.

Division of Solid Waste Managenent Claiborne County Board of Sopervisors Mississippi Department of Natural Port Gibson, Mississippi 39150 Resoorces P. O. Box 10385 Jackson, Mississippi 39209 Regional-Mministrator, Region 11 U.S. Eclear Regulatory Consnission Mr. John G. Cesare.

101 Marietta St., Suite 2900 Director, Noclear Licensing Atlanta, Georgia 30323 System Energy Resources, Inc.

P. O. Box 469 Port Gibson, Mississippi 39150 Mi ke Moore, Attorney General Frank Spencer, Assist. Attorney General Mr. C. B. Hogg, Project Manager State of Mississippi Bechtel Power Corporation Post Office Box 22947 P. O. Box 2166 Jackson, Mississippi 39225

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Houston, Texas 77252-2166 Mr. H. O. Christensen Senior Resident Inspectcr U.S. Nclear Regulatory Commission Roote 2, Box 399 Port Gibson, Mississippi 39150 l

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