ML18092B214
| ML18092B214 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 07/09/1986 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML18092B213 | List: |
| References | |
| REF-GTECI-A-49, REF-GTECI-RV, TASK-A-49, TASK-OR NUDOCS 8607180053 | |
| Download: ML18092B214 (3) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION REGARDING PROJECTED VALUES OF MATERIAL PROPERTIES INTRODUCTION FOR FRACTURE TOUGHNESS REQUIREMENTS FOR PROTECTION AGAINST PRESSURIZED THERMAL SHOCK EVENTS PUBLIC SERVICE ELECTRIC AND GAS COMPANY SALEM NUCLEAR GENERATING STATION, UNIT 1 DOCKET NO. 50-272 As required by 10 CFR 50.61, 11Fracture Toughness Requirements for Protection Against Pressurized Thermal Shoe~' (PTS Rule) which was published in the Federal Register July 23, 1985, the licensee for each operating pressurized water reactor 11shall submit projected values of RT (at the inner vesse*l surface) of reactor v*essel beltline materials by g~i~ng values from the time of submittal to the expiration date of the operating license.
The assessment must specify the bases for the projection including the assumptions regarding core loading patterns. This assessment must be submitted by January 23, 1986, and must be updated whenever changes in core loadings, surveillance measurements or other information indicate a significant change in projected value 11
- By letter dated January 20, 1986, the Public Service Electric and Gas Company (the licensee) submitted projected values of RTPTS together with material properties and fast neurtorn fluence of reactor v~ssel beltline material for the Salem Nuclear Generating Station Unit 1.
The following evaluation concerns the estimation of the fluence to the end of the current operating license and to 32 effective full power years for Salem Unit 1 and the corresponding values for the RTPTS" EVALUATION OF THE MATERIAL ASPECTS The controlling beltline material from the standpoint of PTS susceptibility was identified to be lower shell plate B 2402-1.
The material properties of the controlling material and the associated margin and chemistry factor were reported to be:
/~~~6~ol77118sooo!Y5~3;-;:8
- -.;6~0
- 7;
- 0
-:::9----1 P DR ADOCK. 05000272 PDR
Cu (copper content, %)
Ni (nickel content, %)
I (Initial RTPTS' OF)
M (Margin, F)
CF (Chemistry Factor, °F) Utility Submittal 0.24 0.52
+45 48 Staff Evaluation 0.24 0.52
+45 48 146.5 The controlling material has been properly identified.
The justification given for the copper and nickel contents and the initial RTNOT are acceptable.
The margin has been derived from consideration of the bases fOr these values, following the PTS Rule, Section 50.61 of 10 CFR Part 50.
Equation 1 of the PTS Rule governs, and the chemistry factor is as shown above.
EVALUATION OF THE FLUENCE ASPECTS The value of the fluence was estimated as of. the date of the submittal January 20, 1986, to the expiration of the current operating license (September 25, 2008) and to 32 effective full power years, i.e., the end of the plant design lifetime.
The licensee used the code DOT 4.3 which is generally accepted for deep _
neutron transport calculations with* a P3 and SR approximations.
The (Watt) spectra for U-235 and Pu-239 were ENDF/B-V bas~d and the "Bugle 80 11 cross section data set was used which is also derived from ENDF/B-IV.
All of the above constitute an acceptable methodology.
The 1/8 core geometry was represented by 82x45 mesh points and the pin power distribution was estimated using PDQ and the SORREL code to adopt the source term to DOT 4.3.
Cycle 6 fluxes were used for the extrapolation for future low leakage loadings, which is acceptable.
The results of the calculation were conservatively adjusted to the results of two surveillance capsules.
This represents a conservative and acceptable application of the methodology.
In this manner the estimated value of the peak fluI~ce on2the intermediate shell plate is 0.39, 1.46 and 1.88 (in units of 10 n/cm ) for January 20, 1986, September 25, 2008 and 32 effective full power years, respectively.
EVALUATION OF THE CALCULATED RTPTS According to the PTS Rule, 10 CFR 50.61, the applicable equation for calculating RTPTS is:
Where:
RTPTS = I+M+(-10+470xCu + 350xCuxNi)xf* 27 I = initial RTNDT = 45°F M = uncertainty = 48°F
~-~-*-*--*--*---------.--.. --*--------- *-* -- -- --****----
,.I I
~ -
"'- Cu
= % copper in plate B 2803-3 =. 24.
Ni
= % nickel in plate B 2083-3 =.52 f
= peak fluence (E > 1.0 MeV) on plate
-19. 2 B 2402-1 x 10 cm In Then, the equation for RTPTS yields for 32 effective full power years:
RTPTS = 45+48+(-10+470x0.24+350x0.24x0.52)xl.880. 27
= 93+146.6xl.1858 = 266.8°F CONCLUSIONS The licensee has calculated a RTPTS of 266.8°F for the limiting plate material for 32 effective full power years which is less than the applicable screening criterion of 270°F.
At the expiration of the current operating license the RT
= 255.4°F < 270°F and is acceptable.
For the preseot value the same eqeA~ion yields RTP.T = 206.7°F.
In order for us to confirm the licensee 1s projected estimatea ~TPTS throughout the life of the license we will request the licensee to submit a re-evaluation of the RTp and comparison to the predicted value with future Pressure-Temperature Iilbmittals which are required by 10 CFR 50, Appendix G.
It should be noted that this re-evaluation is a requirement by 10 CFR 50.61, whenever core loadings, surveillance measurements, or other information indicate a significant change in projected value.
Date:
Principal Contributors:
L. Lois P. N.-Randall