ML20147H437
| ML20147H437 | |
| Person / Time | |
|---|---|
| Site: | River Bend  |
| Issue date: | 03/31/1997 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20147H417 | List: |
| References | |
| GL-88-11, NUDOCS 9704030116 | |
| Download: ML20147H437 (5) | |
Text
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't SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. XXX TO FACILITY OPERATING LICENSE NO. NPF-47 f
ENTERGY OPERATIONS INCORPORATED 4
i RIVER BEND STATION I
DOCKET NO. 50-458
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1.0 INTRODUCTION
By letter dated January 10, 1997, the licensee submitted changes related to c
the pressure-temperature (P-T) limits in the River Bend Station Technical e
Specifications (TS). The licensee revised the P-T limits to provide new i
limits that are valid to 12 effective full power years (EFPY).
The staff evaluates the P-T limits based on the following NRC regulations and guidance: Appendix G to 10 CFR Part 50: Generic Letters (GL) 88-11 and 92-01:
Regulatory Guide (RG) 1.99. Rev. 2; and Standard Review Plan (SRP)
Section 5.3.2.
Appendix G to 10 CFR Part 50 requires that P-T limits for the reactor vessel must be at least as conservative as those obtained by Appendix G to Section XI of the American Society of Mechanical Engineers l
(ASME) Boiler and Pressure Vessel Code. GL 88-11 requires that licensees use the methods in RG 1.99. Rev. 2. to predict the effect of neutron irradiation 3
on the adjusted reference temperature (ART) of reactor vessel materials. The ART is defined as the sum of initial nil-ductility transition reference j
temperature (RTm) of the material, the ircrease in RTuoz caused by neutron irradiation, and a margin to account for uncertainties in the prediction i
method. The inicrease in RT, is calculated from the product of a chemistry 1
factor and a fluence factor.
The chemistry factor may be calculated using credible surveillance data, i
obtained by the licensee's surveillance program, as directed by Position 2 of Regulatory Guide (RG) 1.99. Rev. 2.
If credible surveillance data are not available. the chemistry factor is calculated dependait upon the amount of copper and nickel in the vessel material as specified in Table 1 of RG 1.99.
~Rev 2.
GL 92-01 requires licensees to submit reactor vessel materials data.
l which the staff uses in the review of the P-T limits submittals.
i SRP 5.3.2 provides guidance on calculation of the P-T limits using linear elastic fracture mechanics methodology specified in Appendix G to Section III of the ASME Code. The linear elastic fracture mechanics methodology postulates sharp surface defects that are normal to the direction of maximum ATTACHMENT 1 9704030116 970331 PDR ADOCK 05000458 p
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. stress and have a depth of one-fourth of the reactor vessel beltline thickness (1/4T) and a length of 1-1/2 times the beltline thickness. The critical locations in the vessel for this methodology are the 1/4T and 3/4T locations, which correspond to the maximum depth of the postulated inside surface and outside surface defects, respectively.
2.0 EVALUATIDN i
For the River Bend Station reactor vessel. the licensee determined that the most limiting material at the 1/4T and 3/4T locations is the axial weld that was fabricated using tandem electrodes. Tilis weld was fabricated using weld wire heat 5P6756. The licensee calculated an ART of 72.3*F at the 1/4T location and 55.2*F at the 3/4T location at 12 CFFY. The neutron fluence used in the ART calcylation was 1.79 x 10 n/cm; at the 1/4T location and i
8 0.93 x 10 n/cm at the 3/4T location. The initial RT for the limiting weld was -50*F.
ThemargintermusedincalculatingtheART,forthelimitingweld was 56*F.
i The staff performed an independent calculation of the ART values for the limiting material using the methodology in RG 1.99. Revision 2.
Based on these calculations, the staff verified that the licensee's limiting material for the River Bend Station reactor vessel is the axial weld that was fabricated using tandem electrodes (heat 5P6756). The staff's calculated ART value for the limiting material agreed with the licensee's calculated ART i
value.
4 Substituting the ART values for River Bend Station into equations in SRP 5.3.2, the staff verified that the proposed P-T limits satisfy the requirements in Paragraph IV.A.2 of Appendix G of 10 CFR Part 50.
3 In addition to beltline materials. Appendix G of 10 CFR Part 50 also imposes a minimum temper 6ture at the closure head flange based on the reference temperature for the flange material.
Section IV.A.2 of Appendix G states that when the pressure exceeds 20% of the preservice system hydrostatic test 3ressure, the temperature of the closure flange regions highly stressed by the Jolt 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.
Based on the flange RT of 10*F for River Bend Station, the staff has determined that the propos,ed P-T limits have i
satisfied the requirement for the closure flange region during normal operation and inservice leak and hydrostatic testing.
3.0 CONCLUSION
The staff has performed an independent analysis to verify the licensee's proposed P-T limits. The staff concludes that the proposed P-T limits for leatup, cooldown, inservice leak and hydrostatic testing and core criticality are acceptable to 12 EFPY since the limits conform to the requirements of Appendix G of 10 CFR Part 50 and GL 88-11.
Hence, the proposed P-T limits may be incorporated in the River Bend Station Technical Specifications.
4 4.0 REFERFNCES 1.
Regulatory Guide 1.99. Radiation Embrittlement of Reactor Vessel Materials. Revision 2. Hay 1988 2.
NUREG-0800. Standard Review Plan. Section 5.3.2:
Pressure-Temperature Limits 3.
Code of Federal Regulations. Title 10. Part 50. Appendix G. Fracture Toughness Requirements 4.
Generic Letter 88-11. NRC Position on Radiation Embrittlement of Reactor Vessel Materials and its Impact on Plant Operations. July 12, 1988 5.
ASME Boiler.and Pressure Vessel Code.Section III. Appendix G for Nuclear Power Plant Components. Division 1. " Protection Against Nonductile Failure" 6.
January 10. 1997. Letter from J. R. McGaha, Jr. to USNRC Document Control Desk.
Subject:
River Bend Station Unit 1 Licensee Amendment Recuest 96-09. Change to Technical Specifications 3.4.11. "RCS Pressure anc Temperature (P-T) Limits." Figure 3.4.11-1
" Minimum Temperature Required vs. RCS Pressure" 7.
October 22, 1996. Letter from G. Stevens (Structural Integrity Associates) to E. J. Zoch (Entergy Operations. Inc.)
Subject:
Revised (12 EFPY) P-T Curves for River Bend Station.
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1
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,'1 SALP INPUT l
FACILITY NAME: River Bend Station 4
SUMMARY
OF REVIEW ACTIVITIES The staff' reviewed the licensee's proposed changes to pressure-temperature 1
(P-T) limits in the River Bend Station Technical Specifications.
Generic j
Letter. (GL) 88-11 recommends that licensees use' Regulatory Guide 1.99, Rev. 2.
to calculate the adjusted nil-ductility reference temperature. ART, which is a j
parameter used in establishing the P-T limits.
The staff verified the licensee's calculated ART of the limiting beltline material. The staff verified the licensee *s P-T limits using Standard Review Plan 5.3.2. and the j
limiting ART.
NARRATIVE DISCUSSION OF LICENSEE PERFORMANCE-FUNCTIONAL AREA l
SAFETY ASSESSMENT /0UALITY VERIFICATION 4
The, licensee's submittal adequately described the Technical Specification (TS) changes, and provided the appropriate information to technically support the P-T limits evaluation. The submittal was well prepared and concise.
4 Author:
A. Lee 415-2735 ATTACHMENT 2 i
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- MEMORAND T0:
William D. Beckner.Pr'oject Directori
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Project Directorate IV-1 Division of Reactor Projec.ts. III & IV l
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FROM:
KeithR.Wichman.SectionChief
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Material Integrity Section 4
Materials and-Chemical Engineering Brancip' Division of Engineering f
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SUBJECT:
RIVER BEND STATION: PRESSURE TEMPERATURE LIMITS EVALUATION l
License:
otergy Operations Incorporated'
-TAC No.:
M97834 Review Status:
Com' plete.
letterdatedJanua\\
ry 10. 1997, the lice [see submitted changes related to 1
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-t e pressure-temperature (P-T) limits in the River Bend Station Technical
. Specifications (TS). The licensee revised the P-T limits to provide new
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limits that are valid to 12 effective full power years (EFPY).
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Based on our evaluation o the/ubmittak we conclude that the proposed P-T limits for heatup. cooldown inservice ltak and hydrostatic testing and core criticality are acceptable to 12 EFPY, and may be incorporated in the River f
Bend Station "
J Our evaluation is subm tted as ttachment 1 and our SALP input is submitted as.
ThiVcompletesourkffortsforTACNO.M97834.
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Docket No..
50e458 Attachment s stated j
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MMayfield G:\\ LEE \\RIVERBND.P T
~To receive a copy of this document, indicate in the box C-Copy w/o' attachment / enclosure E-Copy with attachment / enclosure N - No copy
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DE:EMCB s DEiEMCB NAME Alee N BEllioth 7
KWichman
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DATE 3M/97 3/'/97 3/ /97' I
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