ML17219A353
| ML17219A353 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 02/10/1987 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML17219A351 | List: |
| References | |
| NUDOCS 8702190059 | |
| Download: ML17219A353 (4) | |
Text
W
~P,S REGS~
(4 P0' Qi IP +~*y4 UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 Enclosure 2
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION REGARDING PROJECTED VALUES ON MATERIAL PROPERTIES FOR FRACTURE TOUGHNESS RE UIREMENTS FOR PROTECTION AGAINST PRESSURIZED THERMAL SHOCK EVENTS FLORIDA POWER AND LIGHT COMPANY ET AL.
ST.
LUCIE PLANT UNIT NO.
2 DOCKET NO. 50-389 INTRODUCTION As required by 10 CFR 50.61, "Fracture Toughness Requirements for Protection Against Pressurized Thermal Shock" (PTS Rule), which was published in the Federal Register July 23, 1985, the licensee for each operating pressurized water reactor "shall submit projected values of RT T (at the inner vessel surface) of reactor vessel beltline materials by g(vying 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 values."
By letter dated January 23, 1986 (L-86-25),
as supplemented by letter dated February 4, 1986, the Florida Power and Light Company, the licensee for the St.
Lucie Plant, Unit No. 2, submitted information on the material properties and fast neutron fluence (E
> 1.0 Mev) of the reactor pressure vessel in compliance with the requirements of 10 CFR 50.61.
Similar information was also submitted as part of another licensing action by letter dated November 5,
1983.
The following evaluation concerns the estimation of the fluence to the reactor pressure vessel to the end of the current license (April 6, 2023) and the corresponding value of the RTPTS.
EVALUATION OF THE MATERIALS ASPECTS The controlling beltline material from the standpoint of PTS susceptibility was identified to be the intermediate shell plate M-605-2.
moaj.SO0S9 EI70aiO PDR AOQCK 05000335 PDR The material properties of the controlling material and the associated margin and chemistry factor were reported to be:
Utilit Submittal Staff Evaluation Cu (copper content, X)
Ni (nickel content, X)
I (Initial RTNDT, 'F)
M (Margin, F)
CF (Chemistry Factor, F)
- 0. 13
- 0. 62
+10
+48
- 0. 13
- 0. 62
+10
+48
- 79. 3 The controlling material has been properly identified.
The justifications given for the copper and nickel contents and the initial RTN are acceptable.
The margin has been derived from consideration 0 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 methodology for the fluence calculation was based on the discrete ordinates two dimensional code DOT 4. 3.
A detailed geometrical representation was used as input to an eighth core.
PDg calculated pin-by-pin source representation was used with the BUGLE-80, an ENDF/IY-B based cross section
- set, and a
P3 scattering and Ss quadrature approximations.
Extrapolation to the end of the current operating license was based on conservative future loading schemes.
The methodology, the cross sections and the approximations used are acceptable.
EVALUATION OF THE CALCULATED RT The equation specified in 10 CFR 50.61 as applicable for the St.
Lucie 2
plant is:
RTpTS where:
= I+M(-10+470xCu+350xCuxNi)xf '
= Initial RT D
M = Uncertaint) Margin Cu = w/o Copper in shell, plate M-605-2 Ni = w/o Nickel in shell plate M-605-2 f = peak azimuthal fluence to the end of the current license (E >, 1.0 MeV) in units of 10'/cm
=10 F
=48F
= 0.13
= 0.62
= 4.79 Therefore:
RTPTS 10 48+( 10+470x0. 13+350x0. 13x0. 62)x4. 79
= 58+79.3x1.526
= 179'F which is lower than 270'F, the applicable 10 CFR 50.61 screening criteria and is acceptable.
CONCLUSIONS The licensee and the staff have calculated a
RTPT of 179'F for the limiting material at the expiration date of the license.
)his is less than 270 F which is the screening criterion for the limiting material at the expiration date of the license.
This is acceptable and thus meets the requirements of the PTS Rule.
In order for us to confirm the licensee's projected estimated RT TS throughout the life of the license, we will request the licensee to submit 3
re-evaluation of the RT and comparison to the predicted value with future pressure temperature sufiiifttals which are required by 10 CFR Part 50, Appendix G.
February 10, 1987 Principal Contributors:
P. Randall, L. Lois, and E. Tourigny
References 1.
Letter from C.
0.
Woody, Florida Power and Light Company, to F. Miraglia, NRR, dated January 23, 1986 Letter from J.
W. Williams, Florida Power and Light Company, to H.
R.
- Denton, NRR, dated November 5, 1985 and attachment BAW-1880 dated September 1985.
3.
Letter from C. 0.
Woody, Florida Power and Light Company, to F. J. Miraglia, NRR, dated February 4, 1986.