HL-5284, Forwards Response to RAI Re TS Rev Request on pressure-temp Limits
| ML20132G209 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 12/17/1996 |
| From: | Beckham J GEORGIA POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20132G212 | List: |
| References | |
| HL-5284, NUDOCS 9612260206 | |
| Download: ML20132G209 (10) | |
Text
,
l Georgia Power Company i
40 invemess Center Parbway i
Post Office Box 1295 Birmingham. Alabama 35201 l
Telephone (205) 877 7279 i
d hNs$e*n'"' Nuciear GeorgiaPbwer -
i Hatch Project December 17, 1996 a subsufwy of I
The southem comrwry l Docket Nos. 50-321 1 HL-5284 50-366 i
U.S. Nuclear Regulatory Commission
)
. ATTN: Document Control Desk Washington, D.C. 20555 Edwin I. Hatch Nuclear Plant l
Response to Request for Additional Information:
Technical Specifications Revision Request on Pressure-Temperature Limits Gentlemen:
- i On December 2,1996, you requested additional information regarding our recent Technical Specifications revision request on pressure and temperature limits for Plant Hsch Unit I and -
i Unit 2. Enclosed are our responses to your questions. We have revised pages 3.4-22 of the j
Unit I and Unit 2 based on question number 1. Accordingly, these pages are being re-submitted.
{
Additionally, we are re-submitting the Unit 1 Pressure-Temperature graphs, Figures 3.4.9-1, 3.4.9-2, and 3.4.9-3. These graphs include the 16 Effective Full Power Year (EFPY) curves fer Hatch Unit 1. The 16 EFPY curve will aid us in the upcoming Unit 1 outage by reducing the j
amount'of time necessary to reach rated temperature for the pressure tests. We are therefore.
re-submitting the graphs to include this curve in the Unit I graphs. contains our responses to the three questions. Enclosure 2 contains the resubmitted j
pages and the corresponding mark-ups.
No changes are necessary to thejustification and the 10 CFR 50.92 evaluation of the original submittal.
Please contact this office ifyou have further questions.
Sincerely,
)
0'y/Y)Ar k
J. T. Beckham, Jr.
t
Enclosures:
(See next page.):
9612260206 961217 PDR ADOCK 05000321 l
P PDR 1
~
GeorgiaPower d U.S. Nuclear Regulatory Commission Page 2 December 17, 1996
Enclosures:
- 1. Response to Request for AdditionalInformation: Technical Sr :ifications Revision Request on Pressure-Temperature
- 2. Page Change Instructions OCV/eb cc: Georzia Power Company Mr. H. L. Sumner, Nuclear Plant General Manager NORMS U.S. Nuclear Reeulatorv Commission. Washington. D.C.
Mr. K. Jabbour, Licensing Project Manager - Hatch U.S. Nuclear Regulatorv Commission. Region 11 Mr. S. D. Ebneter, Regional Administrator Mr. B. L. Holbrook, Senior Resident Inspector - Hatch i
i HL-5284
i j
1 Edwin I. Hatch Nuclear Plant Response to Request for Additional Information:
Technical Specifications Revision Request on Pressure-Temperature Limits The following are the responses to your letter of December 2,1996, requesting additional information regarding our recent Technical Specifications revision request on pressure-j temperature limits for Plant Hatch Units 1 and 2.
A transcription of each question precedes the responses:
1.
NRC Request i
It appears that the revised statement of Surveillance Requirement (SR) 3.4.9.l(a)
{
regarding Figures 3.4.9-1, Pressure / Temperature Limits for Inservice Hydrostatic and Inservice Leakage Tests, and 3.4.9-2, Pressure / Temperature Limits for Non-Nuclear Heatup, Low Power Physics Tests, and Cooldown Following a Shutdown, is not consistent with the captions of these figures. Please correct this apparent discrepancy.
i GPC Response The descriptions of the figures have been reversed in the text of Surveillance Requirement 3.4.9.1. As a result, page 3.4-22 is being re-submitted for both units.
- ' includes the re-submitted pages along with their mark-up.
2.
NRC Reguest Provide the generic P versus (T-RTmr) curve and its methodology for the upper vessel that are mentioned in GENE-523-A137-1295, and the ratio of the worst stress around the feedwater nozzle to the membrane stress at places with no geometry discontinuity. Confirm that the generic P versus (T-RTer) curve for the bottom head that you are using is the same as that provided by Illinois Power in support of its recent pressure / temperature limits revision (dated February 22,1996) for the Clinton Power Station that has been reviewed by the staff. Otherwise, please provide similar information as requer.ed for the upper vessel curve.
GPC Resoonse When GE developed non-beltline P-T curves, the approach was to develop curves for a conservatively large BWR/6 (nominal 251-inch inside diameter) and then apply the curves generically to other vessels by using the appropriate RTmr alues.
v HL-5284 El-1
Response to Request for AdditionalInformation:
Pressure-Temperature Limits The one characteristic of the upper vessel and bottom head, that made the analysis different from a shell analysis like that for the beltline, was the presence of nozzles and control rod drive (CRD) penetration holes, with their associated stress concentrations and higher thermal stresses for certain transient conditions.
Since the generic bottom head curve (CRD curve) is the same as provided by Illinois Power in support ofits recent P-T limits revision, confirmation that the generic bottom head curve is the same will be provided first. Since the NRC specifically requested information regarding the feedwater nozzle curve, the methodology for the upper vessel (feedwater nozzle) curve will be provided also.
The bottom head methodology is as follows:
i The generic pressure test P-T curves for the bottom head are the same as those provided by Illinois Power in support ofits recent P-T limits revision. The generic pressure test P-T curve was generated by scaling the Ki of 154.3 ksiVin by the nominal pressures and calculating the associated (T-RTer):
i Nominal Pressure Ki (T-RTer)
(psig)
(ksiVin)
(*F) 1563 154.3 161 1400 138.2 151 1200 118.5 138 1000 98.7 121 800 79.0 99 600 59.2 66 400 39.5 1
The generic curves are applicable to Plant Hatch as follows:
The P-T curve is dependent on the K value calculated, which is proportional to the i
stress and the crack depth according to the relationship:
Ki et a Vxa The stress is proportional to R/t and, for the P-T curves, crack depth, a, is t/4.
Thus, K is proportional to R/Vt. The generic curve value of R/Vt, based on the i
BWR/6,251-inch bottom head dimensions, is Generic R/Vt 138 / 48 49
=
=
HL-5284 El-2
j Response to Request for AdditionalInformation-i Pressure-Temperature Limits l
i l
The Hatch specific bottom head dimensions are R = 110.5 inches and t = 7 inches.
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Hatch specific R/Vt 110.5 / V7 42
=
=
Since the generic value of R/Yt is greater than that for Hatch, the generic P-T curve is conservative when applied to the Hatch bottom head.
As discussed below, the highest RTer for the bottom head materials is 10*F for Unit I and 50 F for Unit 2. The generic pressure test P-T curve is applied to the Hatch bottom head by shifting the P vs. (T-RTer) values above to reflect the RTer j
value of 10 F for Unit 1 and 50 F for Unit 2.
The resulting P-T Values are listed below:
Nominal Pressure Bottom Head Temperature (psig)
( F) l Unit 1 Unit 2 j
1400 161 201 1200 148 188 i
1000 131 171 800 109 149 600 76 116 400 11 51 1
The highest RTer for the bottom head plates and welds is 10 F for Unit I and 50 F for Unit 2, based on fracture toughness data for the plates, shown in Table 1 (below). The bottom head welds have RTer values less than 10 F for Unit I and 50 F for Unit 2, based on the vessel purchase specification requirements and QA documentation confirming that there were no bottom head plate or weld RTer values greater than 10 F for Unit I and 50 F for Unit 2.
i HL-5284 El-3
Response to Request for AdditionalInformation:
Pressure-Temperature Limits Table 1. Fracture Toughness of Bottom Head Plates Long Charpy Test impact Drop Plate Temperature Energy Weight RTwr Location Heat No.
( F)
(ft-lb)
( F)
( F)
Conunents Unit 1 Bottom Head 2 F/ft-lb Recirculation correlation Outlet Nozzle AV-2798 10 35,51,42 0
10 applied.
Drop Bottom Head weight Dome Plates C4351-3 10 70,68,60 10 10 bounding.
Unit 2 2 F/ft-lb Bottom Head correlation Dome Plates C8658-2 40 30,32,34 20 50 applied.
The upper curves methodology is as follows:
CBI Nuclear (CBIN) modeled the BWR/6,251-inch feedwater nozzles to compute local stiesses for determination of the stress intensity factor, Ki. The results of that computation were K = 143.1 ksidin for an applied pressure of 1563 psig preservice i
hydrotest pressure. The computed value of(T-RTmyr) was 154 F.
To evaluate the CBIN result, Ki is calculated for the upper vessel nominal stress, PR/t, according to the methods in ASME Code Appendix G (Section III or XI).
The result is compared to that determined by CBIN in order to quantify the K magnification associated with the stress concentration created by the feedwater nozzles.
A calculation of Ki shown below using the BWR/6,251-inch dimensions:
Vessel Radius, R 126.7 inches Vessel Thickness, t 6.5 inches Vessel Pressure 1563 psig Pressure stress PR/t 1563 psig
- 126.7 inches a
=
=
(6.5 inches) 30466 psi o
=
HL 5??4 El-4
_ ~ _
i l
Response to Request for Additional Information:
Pressure-Temperature Limits j
i The factor F(a/rs) from Figure A5-1 of WRC -(Welding Research Council)
Bulletin 175 is 1.6 where:
lesser of1/4 Tu or 1/4 T, l
a
=
Tu = 71/8 inch Tv = 61/2 inch R; + 0.29 R, f
rw
=
Ra = apparent radius of nozzle = 6 inches i
R. =. actual inner radius of the nozzle = 3.25 inches i
a/rw =
1.63/6.94 = 0.23 Therefore, the ratio of stress around the feedwater nozzle to the membrane stress at
- places with no geometric discontinuity is 1.6.~
Including the safety factor of 1.3, the stress intensity factor, Ki s 1.3 o 4xa
- F(a/r ):
l i
s
)
1.3
- 30.466
- 4x*l.63
- 1.6 = 143 ksiVm Nominal Ki
=
i The method to solve for (T-RTuor) for a specific K is based on the curve in Figure i
G-2210-1 in ASME Appendix G:
i (T-RTwor) 1n [(Ki-26.78) /1.223] / 0.0145 - 160
=
' 1n [(143 - 26.78) /1.223] / 0.0145 - 160 (T-RTwor)
=
(T-RTwor) 154 F
=
The generic pressure test P-T curve was generated by scr. ling 143 ksidin by the nominal pressure and calculating the associated (T-RTwor):
Nominal Pressure Ki (T-RTwor)
(psig)
(ksiVin)
(F) 1563 143 154 1400 128 145 1200 110 131 1000 92 114
)
800 73 91 600 55 56 400 37
-16 l
HL-5284 El-5
Response to Request for Additional Information:
Pressure-Temperature Limits The generic upper vessel curve methodology is applied to Plant Hatch as follows:
The P-T curve is dependent on the Ki value calculated, which is proportional to the stress and the crack depth according to the relationship:
Ki a o Vna The stress is proportional to R/t and, for the P-T curves, crack depth, a, is t/4.
Thus, Kiis proportional to R/Vt. The generic curve value of R/Vt, based on the BWR/6,251-inch feedwater nozzle dimensions, is Generic R/Vt 127 / 46.5 50
=
=
The Hatch specific dimensions applicable to the feedwater nozzle are R = 110 inches and t = 5 inches.
Hatch specific R/Vt 110 / V5 49
=
=
Since the generic value of R/4t is greater than that for Hatch, the generic P-T curve is conservative when applied to the Hatch feedwater nozzle.
As discussed below, the highest RTer for the nozzle materials is 40 F for Unit I and 26 F for Unit 2. The generic pressure test P-T curve is applied to the Hatch feedwater nozzle curve by shilling the P vs. (T-RTmT) values above to reflect the RTmr value of 40 F for Unit I and 26 F for Unit 2. The resulting P.T values are below:
Nominal Pressure Upper Vessel Temperature (psig)
(F)
Unit 1 Unit 2 1400 185 171 1200 171 157 1000 154 140 800 131 117 600 96 82 400 24 10 HL-5284 El-6
.~.__
t Response to Request for AdditionalInformation:
Pressure-Temperature Limits J
h The highest RTer for the upper vessel nozzles, plates and welds is 40 F for Unit I and 26 F for Unit 2, based on fracture toughness data for the plates, shown in Table 2 (below). The upper vessel welds have RTmr alues less than 40 F for v
I Unit 1 and 26'F for Unit 2, based on the vessel purchase specification requirements j
and QA documentation confirming that there were no upper vessel plate or weld RTer alues greater than 40 F for Unit I and 26 F for Unit 2.
v Table 2. Fracture Toughness of Upper Vessel Plate j
l Long Charpy Test Impact Drop Plau Temperature Energy Weight RTer i
Location Heat No.
('F)
(ft-lb)
(*F)
( F)
Comments 1
Unit 1 2 F/ft-lb Upper Vessel correlation l
Steam Outlet applied, but Nozzle drop weight AV-1576 10 42,44,64 40 40 bounding.
j Unit 2
- Upper Vessel 2 F/ft-lb Steam Outlet correlation Nozzle Q2Q30W 10 27,34,33 10 26 applied.
3.
NRC Reautst Provide the copper and nickel contents of the beltline limiting material for the Hatch Unit 2 vessel and confirm that all chemistry and material data used in generating the beltline P-T limit curves for Unit 2 are the same as those in your Generic Letter 92-01 submittals.
GPC Response The Hatch Unit 2 copper and nickel contents of the limiting beltline material are shown in the table below for report GE-NE-523-A137-1295 and the Generic Letter 92-01 submittal.
HL-5284 El-7
\\
Response to Request for Additional Information:
Pressure-Temperature Limits 4
Chemistry for the Limiting Beltline Material i
Lower Longitudinal Weld, ID. 101-842, Heat 10137, Linde 0091 Initial Source
% Cu
% Ni CF RTer GE-NE-523-A137-1295 0.23 0.50 154.5
-50 Generic Letter 92-01 0.23 0.50 154.5
-50 2
4 i
a l
4 i
'b a
4 4
-l 41 l
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HL-5284 El-8 j