ML023460503
| ML023460503 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 12/31/2002 |
| From: | Gresham J Westinghouse |
| To: | American Electric Power Co, Office of Nuclear Reactor Regulation |
| References | |
| WCAP-15878, Rev 0 | |
| Download: ML023460503 (60) | |
Text
Attachment 4 to AEP:NRC:2349-03 WCAP-15878, REVISION 0, "D. C. COOK UNIT 1 HEATUP AND COOLDOWN LIMIT CURVES FOR NORMAL OPERATION FOR 40 YEARS AND FOR 60 YEARS,"
DATED DECEMBER 2002
Westinghouse Non-Proprietary Class 3 WCAP-15878 December 2002 Revision 0 D. C. Cook Unit 1 Heatup and Cooldown Limit Curves For Normal Operation For 40 Years And 60 Years (oWestinghouse
I I ý WESTINGHOUSE NON-PROPRIETARY CLASS 3 WCAP-15878, Revision 0 D.C. Cook Unit 1 Heatup and Cooldown Limit Curves For Normal Operation For 40 Years and 60 Years Justin H. Ledger December 2002 Prepared by the Westinghouse Electric Company LLC for the American Electric Power Company Approved: r J. A. Gresham, Manager Equipment & Materials Technology WESTINGHOUSE ELECTRIC COMPANY LLC P.O. Box 355 Pittsburgh, Pennsylvania 15230-0355
© 2002 Westinghouse Electric Company LLC All Rights Reserved
i PREFACE This report has been technically reviewed and verified by:
T. J. Laubham This report covers the Heatup and Cooldown Curves based upon the uprate, 40 and 60 years of operation and methodology per WCAP-14040, Rev 2-A.
D.C. Cook Unit I Heatup and Cooldown Limit Curves
ii TABLE OF CONTENTS LIST OF TABLES iv LIST OF FIGURES vi
1.0 INTRODUCTION
1-1 2.0 PURPOSE 2-1 3.0 CRITERIA FOR ALLOWABLE PRESSURE-TEMPERATURE RELATIONSHIPS 3-1
,3.1 Overall Approach 3-1 3.2 Methodology for Pressure-Temperature Limit Curve Development 3-2 4.0 CHEMISTRY FACTOR DETERMINATION 4-1 4.1 Chemistry Factor Methodology 4-1 4.1.1 Application of the Ratio Procedure 2 4.1.2 Temperature Effects on Surveillance Data 4-2 4.2 Surveillance Program Credibility Evaluation 4-5 4.2.1 Application of the Credibility Criteria 4-10 4.2.2 aA and How it was Determined 4-10 5.0 UNIRRADIATED PROPERTIES 5-1 5.1 Initial RTNtmr of Beltline Materials 5-1 5.2 Determination of an 5-2 5.3 Bolt-up Temperature 5-2 6.0 REACTOR VESSEL GEOMETRIC & SYSTEM PARAMETERS 6-1 6.1 Reactor Vessel Physical Dimensions and Operating Conditions 6-1 7.0 FLUENCE FACTOR DETERMINATION 7-1 7.1 Peak Clad Base Metal Interface Fluence for each Beltline Material 7-1 7.2 1/4T & 3/4T Thickness Fluence for each Beltline Material 7-2 7.3 Fluence Factors 7-3 D.C. Cook Unit 1Heatup and Cooldown Limit Curves
I iii TABLE OF CONTENTS - (Continued) 8.0 CALCULATION OF ADJUSTED REFERENCE TEMPERATURE 8-1 8.1 Methodology 8-1 8.2 Adjusted Reference Temperature (ART) Calculations 8-2 9.0 HEATUP AND COOLDOWN PRESSURE-TEMPERATURE LIMIT CURVES 9-1 9.1 Introduction and Methodology 9-1 10.0 ENABLE TEMPERATURE CALCULATIONS 10-1 10.1 ASME Code Case N-641 Methodology 10-I 10.2 32 EFPY Enable Temperature 10-1 10.3 48 EFPY Enable Temperature 10-2 1I REFERENCES 11-1 D.C. Cook Unit I Heatup and Cooldown Limit Curves
iv LIST OF TABLES 4-1 Reactor Vessel Beltline Material Copper and Nickel Content and Calculated CF 4-3 4-2 Calculation of Chemistry Factors using D. C. Cook Unit 1 Surveillance Capsule Data 4-4 4-3 D. C. Cook Unit 1 Surveillance Capsule Data 4-7 4-4 Best-Fit line for D. C. Cook Unit 1 Surveillance Materials 4-8 4-5 Calculation of Residual vs. Fast Fluence 4-9 5-1 Reactor Vessel Material Initial RTNr 5-1 7-1 Calculated Fluence (1019 n/cm2 , E > 1.0 MeV) at the Pressure Vessel 7-1 Clad/Base Metal Interface for the D. C. Cook Unit 1 Reactor Vessel 7-2 Summary of Fluence Values Used to Calculate the D. C. Cook Unit 1 32 EFPY ART 7-2 Values 7-3 Summary of Fluence Values Used to Calculate the D. C. Cook Unit 1 48 EFPY ART 7-3 Values 7-4 Summary of Fluence Factor Values Used to Calculate the D. C. Cook Unit 1 7-4 32 EFPY ART Values 7-5 Summary of Fluence Factor Values Used to Calculate the D. C. Cook Unit 1 7-4 48 EFPY ART Values 8-1 Calculation of the ART Values for D. C. Cook Unit lfor the l/4T Location and 32 EFPY 8-3 8-2 Calculation of the ART Values for D. C. Cook Unit Ifor the 3/4T Location and 32 EFPY 8-4 8-3 Calculation of the ART Values for D. C. Cook Unit I for the 1/4T Location and 48 EFPY 8-5 8-4 Calculation of the ART Values for D. C. Cook Unit 1for the 3/4T Location and 48 EFPY 8-6 8-5 Summary of the Limiting ART Values to be Used in the Generation of the 8-7 Cook Unit 1 Reactor Vessel Heatup and Cooldown Curves D.C. Cook Unit 1 Heatup and Cooldown Limit Curves
V LIST OF TABLES - (Continued) 9-1 D.C. Cook Unit 1 Reactor Vessel Heatup Curve Data Points for 32 EFPY 9-7 Without Margins for Instrumentation Errors (Includes Vessel Flange Requirements of 180°F and 621 psi per 10CFR50) 9-2 D.C. Cook Unit 1 Reactor Vessel Cooldown Curve Data Points for 32 EFPY 9-9 Without Margins for Instrumentation Errors (Includes Vessel Flange Requirements of 180°F and 621 psi per 10CFR50) 9-3 D.C. Cook Unit 1 Reactor Vessel Heatup Curve Data Points for 48 EFPY 9-11 Without Margins for Instrumentation Errors (Includes Vessel Flange Requirements of 180°F and 621 psi per 10CFR50) 9-4 D.C. Cook Unit 1 Reactor Vessel Cooldown Curve Data Points for 48 EFPY 9-13 Without Margins for Instrumentation Errors (Includes Vessel Flange Requirements of 180°F and 621 psi per 10CFR50)
D.C. Cook Unit 1 Heatup and Cooldown Limit Curves
Vl LIST OF FIGURES 9-1 D.C. Cook Unit 1 Reactor Coolant System Heatup Limitations (Heatup Rate 9-3 of 60°F/hr) Applicable for 32 EFPY (Without Margins for Instrumentation Errors)
(Includes Vessel Flange Requirements of 180°F and 621 psi per IOCFR50) 9-2 D.C. Cook Unit I Reactor Coolant System Cooldown Limitations (Cooldown Rates 9-4 of 0, 20,40, 60 and I00°F/hr) Applicable for 32 EFPY (Without Margins for Instrumentation Errors) (Includes Vessel Flange Requirements of 180°F and 621 psi per 10CFR50) 9-3 D.C. Cook Unit I Reactor Coolant System Heatup Limitations (Heatup Rate 9-5 of 600F/hr) Applicable for 48 EFPY (Without Margins for Instrumentation Errors)
(Includes Vessel Flange Requirements of 180°F and 621 psi per 10CFR50) 9-4 D.C. Cook Unit I Reactor Coolant System Cooldown Limitations (Cooldown Rates 9-6 of 0, 20,40,60 and 100°F/hr) Applicable for 48 EFPY (Without Margins for Instrumentation Errors) (Includes Vessel Flange Requirements of 180°F and 621 psi per IOCFR50)
D.C. Cook Unit I Heatup and Cooldown Limit Curves
1-1
1.0 INTRODUCTION
Heatup and cooldown limit curves are calculated using the adjusted RTNDT (reference nil-ductility temperature) corresponding to the limiting beltline region material of the reactor vessel. The adjusted RTNDT of the limiting material in the core region of the reactor vessel is determined by using the unirradiated reactor vessel material fracture toughness properties, estimating the radiation-induced ARTNDT, and adding a margin. The unirradiated RTNDT is designated as the higher of either the drop weight nil-ductility transition temperature (NDTT) or the temperature at which the material exhibits at least 50 fl-lb of impact energy and 35-mil lateral expansion (normal to the major working direction) minus 600F.
RTNDT increases as the material is exposed to fast-neutron radiation. Therefore, to find the most limiting RTNDT at any time period in the reactor's life, ARTND- due to the radiation exposure associated with that time period must be added to the unirradiated RTNDT (IRTNT). The extent of the shift in RTNmT is enhanced by certain chemical elements (such as copper and nickel) present in reactor vessel steels. The Nuclear Regulatory Commission (NRC) has published a method for predicting radiation embrittlement in Regulatory Guide 1.99, Revision 2, "Radiation Embrittlement of Reactor Vessel Materials"111. Regulatory Guide 1.99, Revision 2, is used for the calculation of Adjusted Reference Temperature (ART) values (IRTNDT + ARTNDT
+ margins for uncertainties) at the l/4T and 3/4T locations, where T is the thickness of the vessel at the beltline region measured from the clad/base metal interface. The most limiting ART values are used in the generation of heatup and cooldown pressure-temperature limit curves for normal operation.
The heatup and cooldown curves documented in this report were generated using the most limiting ART values and the NRC approved methodology documented in WCAP-14040-NP-A, Revision 2 163, "Methodology Used to Develop Cold Overpressure Mitigating System Setpoints and RCS Heatup and Cooldown Limit Curves' with exception of the following: 1) The fluence values used in this report are calculated fluence values (i.e. comply with Reg. Guide 1.190), not the best estimate fluence values. 2) The KIc critical stress intensities are used in place of the Ku critical stress intensities. This methodology is taken from approved ASME Code Case N-6411 91 (which covers Code Case N-6401s] and N-588 10 1). 3) The 1996 Version of Appendix G to Section XI31 will be used rather than the 1989 version.
D.C. Cook Unit 1 Heatup and Cooldown Limit Curves
2-1 2.0 PURPOSE D.C. Cook Unit I has contracted Westinghouse to generate new heatup and cooldown curves for the current end of license and life extension based upon the power uprate. The D.C. Cook Unit 1 heatup and cooldown curves were generated without margins for instrumentation errors. The curves include a hydrostatic leak test limit curve from 2485 to 2000 psig and pressure-temperature limits for the vessel flange regions per the requirements of 10 CFR Part 50, Appendix G12 1.
The purpose of this report is to present the calculations and the development of D.C. Cook Unit 1 heatup and cooldown curves for the current end of license and license renewal. This report documents the calculated adjusted reference temperature (ART) values following the methods of Regulatory Guide 1.99, Revision 2[q, for all the beltline materials and the development of the heatup and cooldown pressure temperature limit curves for normal operation.
D.C. Cook Unit 1 Heatup and Cooldown Limit Curves
3-1 3.0 CRITERIA FOR ALLOWABLE PRESSURE-TEMPERATURE RELATIONSHIPS 3.1 Overall Approach Appendix G to 10 CFR Part 50, "Fracture Toughness Requirements" [2) specifies fracture toughness requirements for ferritic materials of pressure-retaining components of the reactor coolant pressure boundary of light water nuclear power reactors to provide adequate margins of safety during any condition of normal operation, including anticipated operational occurrences and system hydrostatic tests, to which the pressure boundary may be subjected over its service lifetime. The ASME Boiler and Pressure Vessel Code forms the basis for these requirements.Section XI, Division 1, "Rule for Inservice Inspection of Nuclear Power Plant Components", Appendix G 31, contains the conservative methods of analysis.
The ASME approach for calculating the allowable limit curves for various heatup and cooldown rates specifies that the total stress intensity factor, K1 , for the combined thermal and pressure stresses at any time during heatup or cooldown cannot be greater than the reference stress intensity factor, Kl,, for the metal temperature at that time. K1, is obtained from the reference fracture toughness curve, defined in Code Case N-641 of Appendix G of the ASME Code,Section XI. The K1, curve is given by the following equation:
0 02 (1)
Ki, = 33.2 + 20.734
- e1 (T-RTNDT)]
where, Ki, = reference stress intensity factor as a function of the metal temperature T and the metal reference nil-ductility temperature RTNDT This Ki, curve is based on the lower bound of static K, values measured as a function of temperature on specimens of SA-533 Grade B Class 1, SA-508-1, SA-508-2, and SA-508-3 steels.
D.C. Cook Unit I Heatup and Cooldown Limit Curves
3-2 3.2 Methodology for Pressure-Temperature Limit Curve Development The governing equation for the heatup-cooldown analysis is defined in Code Case N-640 of Appendix G of the ASME Code as follows:
C
- K im+ Ki, < Ki, (2)
- where, Kim = stress intensity factor caused by membrane (pressure) stress K,, = stress intensity factor caused by the thermal gradients K = function of temperature relative to the RTNDT of the material C = 2.0 for Level A and Level B service limits C = 1.5 for hydrostatic and leak test conditions during which the reactor core is not critical For membrane tension, the K, corresponding to membrane tension for the postulated defect is:
Kim = Mm * (pR, - t) (3)
Where Mm for an inside surface is given by:
Mm = 1.85 for 4it < 2, M m = 0.926 4it for 2 */t < 3.464, and q
Mm = 3.21 for It > 3.464.
Similarly, Mm for an outside surface flaw is given by:
Mm, = 1.77 for It < 2, Mm = 0.893 4It for 2 4't < 3.464, and Mm = 3.09 for 4t > 3.464.
Where:
Ri = vessel inner radius, t = vessel wall thickness, and p = internal pressure, D.C. Cook Unit I Heatup and Cooldown Limit Curves
3-3 For Bending Stress, the Ki corresponding to bending stress for the postulated defect is:
Klb = Mb
- maximum bending stress, where Mb is two-thirds of Mm For the Radial Thermal Gradient, the maximum K, produced by radial thermal gradient for the postulated inside surface defect is:
Ki, = 0.953x10"3 x CR x t 2 _5 (4) where:
CR = the cooldown rate in OF/hr.
For the Radial Thermal Gradient, the maximum K1 produced by radial thermal gradient for the postulated outside surface defect is:
Ki, =.753x10"3 xHUx t25 (5) where:
HU = the heatup rate in °F/hr.
The through-wall temperature difference associated with the maximum thermal K, can be determined from ASME Section XI, Appendix G, Figure G-2214-1. The temperature at any radial distance from the vessel surface can be determined from ASME Section XI, Appendix G, Figure G-2214-2 for the maximum thermal Ki.
(a) The maximum thermal K, relationship and the temperature relationship in Fig. G-2214-1 are applicable only for the conditions given in G-2214.3 (a)(]) and (2) of Appendix G to ASME Section XI.
(b) Alternatively, the K, for radial thermal gradient can be calculated for any thermal stress distribution and at any specified time during cooldown for a 'A4-thickness inside surface defect using the relationship:
Ki, = (1.0359Co+ 0.6322C, + 0.4753C2 + 0.3855C3) *.fl" (6)
D.C. Cook Unit I Heatup and Cooldown Limit Curves
3-4 or similarly, KIT during heatup for a '/4-thickness outside surface defect using the relationship:
Kit = (1.043Co + 0.630Ci + 0.481 C2 + 0.401 C3) * .JTa (7) where the coefficients CO, C,, C2 and C3 are determined from the thermal stress distribution at any specified time during the heatup or cooldown using the form:
ar(x) = Co+ Ci(x / a) + C2(x / a) 2 + CO(x /a)' (8) and x is a variable that represents the radial distance from the appropriate (i.e., inside or outside) surface to any point on the crack front and a is the maximum crack depth.
Note, that equations 3 through 8 were added to the OPERLIM computer program, which is the Westinghouse computer program used to generate pressure-temperature limit curves. No other changes were made to the OPERLIM computer program with regard to the pressure-temperature curve calculation methodology. Hence, the pressure-temperature curve methodology described in WCAP-14040161 Section 2.6 (equations 2.6.2-4 and 2.6.3-1) remains valid for the generation of the pressure-temperature curves documented in this report with the exceptions described above.
At any time during the heatup or cooldown transient, Kic is determined by the metal temperature at the tip of a postulated flaw at the 1/4T and 3/4T location, the appropriate value for RTNDT, and the reference fracture toughness curve.- The thermal stresses resulting from the temperature gradients through the vessel wall are calculated and then the corresponding (thermal) stress intensity factors, Kl,, for the reference flaw are computed. From Equation 2, the pressure stress intensity factors are obtained and, from these, the allowable pressures are calculated.
For the calculation of the allowable pressure versus coolant temperature during cooldown, the reference flaw of Appendix G to the ASME Code is assumed to exist at the inside of the vessel wall. During cooldown, the controlling location of the flaw is always at the inside of the wall because the thermal gradients produce tensile stresses at the inside, which increase with increasing cooldown rates.
Allowable pressure-temperature relations are generated for both steady-state and finite cooldown rate situations. From these relations, composite limit curves are constructed for each cooldown rate of interest.
D.C. Cook Unit I Heatup and Cooldown Limit Curves
3-5 The use of the composite curvein the cooldowvn analysis is necessary because control of the cooldown procedure is based on the measurement of reactor coolant temperature, whereas the limiting pressure is actually dependent on the material temperature at the tip of the assumed flaw. During cooldown, the 1/4/T vessel location is at a higher temperature than the flufid adjacent to the 'Vessel inner diameter. This condition, of course, is not true for the steady-state situation. It follows that, at any given reactor coolant temperature, the AT (temperature) developed during cooldown results-in a higher value of Kic at the 'AT location for finite cooldown rates than for steady-state operation. Furthermore, if conditions exist so that the increase in Ktc exceeds K1,; the calculated allowable pressure during cooldown will be greater than the steady-state value.
The above procedures are needed because there is no direct control on temperature at the 1AT location and, therefore, allowable pressures may unknowingly be violated if the rate of cooling is decreased at various intervals along a cooldown ramp. The use of the composite curve eliminates this problem and ensures conservative operation of the system for the entire cooldown period.
Three separate calculations are.required to determine the limit curves for finite heatup rates. As is done in the cooldown analysis, allowable pressure-temperature relationships are developed for steady-state conditions as well as finite heatup rate conditions assuming the presence of a 'AT defect at the inside of the wall. The heatup results in compressive stresses at the inside surface that alleviate the tensile stresses produced by internal pressure. The metal temperature at the crack tip lags the coolant temperature; therefore, the Kic for the 'AT crack during heatup is lower than the Kic for the 'AT crack during steady-state conditions at the same coolant temperature. During heatup, especially at the end of the transient, conditions may exist so that the effects of compressive thermal stresses and lower Ktc values do not offset each other, and the pressure-temperature curve based on steady-state conditions no longer represents a lower bound of all similar curves for finite heatup rates when the 'AT flaw is considered.
Therefore, both cases have to be analyzed in order to ensure that at any coolant temperature the lower value of the allowable pressure calculated for steady-state and finite heatup rates is obtained.
The second portion of the heatup analysis concerns the calculation of the pressure-temperature limitations for the case in which a 1/4AT flaw located at the IAT location from the outside surface is assumed. Unlike the situation at the vessel inside surface, the thermal gradients established at the outside surface during heatup produce stresses, which are tensile in nature and therefore tend to reinforce any pressure stresses present. These thermal stresses are dependent on both the rate of heatup and the time D.C. Cook Unit I Heatup and Cooldown Limit Curves
3-6 (or coolant temperature) along the heatup ramp. Since the thermal stresses at the outside are tensile and increase with increasing heatup rates, each heatup rate must be analyzed on an individual basis.
Following the generation of pressure-temperature curves for both the steady state and finite heatup rate situations, the final limit curves are produced by constructing a composite curve based on a point-by-point comparison of the steady-state and finite heatup rate data. At any given temperature, the allowable pressure is taken to be the lesser of the three values taken from the curves under consideration.
The use of the composite curve is necessary to set conservative heatup limitations because it is possible for conditions to exist wherein, over the course of the heatup ramp, the controlling condition switches from the inside to the outside, and the pressure limit must at all times be based on analysis of the most critical criterion.
10 CFR Part 50, Appendix G addresses the metal temperature of the closure head flange and vessel flange regions. This rule states that the metal temperature of the closure flange regions must exceed the material unirradiated RT*Dr by at least 120OF for normal operation when the pressure exceeds 20 percent1 21 of the pre-service hydrostatic test pressure (3106 psig), which is 621 psig for the D.C. Cook Unit 1 reactor vessel.
The limiting unirradiated RTNDT of 60"F occurs in the closure head flange of the D.C. Cook Unit 1 reactor vessel, so the minimum allowable temperature of this region is 180°F at pressure greater than 621 psig without uncertainties. This limit is reflected in the heatup and cooldown curves shown in Figures 9-1 through 9-4.
D.C. Cook Unit 1 Heatup and Cooldown Limit Curves
4-I 4.0 CHEMISTRY FACTOR DETERMINATION 4.1 Chemistry Factor Methodology:
The calculations of chemistry factor (CF) values for the D.C. Cook Unit I reactor vessel beltline materials are performed in accordance with Regulatory Guide 1.99, Revision 2 as follows:
The CF is based on the Cu and Ni weight % of the material or it is based on the- results of surveillance capsule test data. When the weight percent of copper and nickel is used to determine the CF, the CF is obtained from either Table I or Table 2 of Regulatory Guide 1.99, Revision 2. The results of this method are given in Table 4-1.
When surveillance capsule data is used to determine the CF, the CF is determined as follows:
CF- CFn = [A, X fO0 28-0 IRogfi)] (9)l'"tJ
[f (028-0 9)*Io]f9 Yn Where: n = The Number of Surveillance Data Points A, = The Measured Value of ARTNDr f, Fluence for each Surveillance Data Point When the surveillance weld copper and nickel content differs from that of the vessel weld, the measured values of ARTNDT are adjusted by multiplying them by the ratio of the chemistry factor for the vessel weld to that for the surveillance weld based on the copper and nickel content of the materials. The Ratio Procedure is documented in Regulatory Guide 1.99 Revision 2 Position 2.1.
D.C. Cook Unit I Heatup and Cooldown Limit Curves
4-2 4.1.1 Application of the Ratio Procedure The D. C. Cook Unit 1 Surveillance Weld was fabricated from weld heat 13253, while the lower shell axial welds included heats 13253/12008. Thus, the D. C. Cook Unit I surveillance weld data was not used for the determination of D. C. Cook Unit 1 pressure-temperature Curves.
However, surveillance weld data does exist for weld heat 1P3571 from Kewaunee and Maine Yankee. This is the same heat as the intermediate to lower shell circumferential weld for D. C. Cook Unit 1. Despite the fact the welds are of the same heat, the weight percent copper and nickel of the surveillance weld metal differs slightly versus the overall best estimate chemistry for the vessel weld metal (per D. C. Cook Design Information Transmittal, D1T-B-02230-001T). As reported in Table 4-1, the chemistry factor of the Kewaunee/Maine Yankee surveillance Weld is 211.9°F, while the vessel weld chemistry is 214.0°F. This produces a ratio of 1.01. Therefore a ratio of 1.01 was applied to the chemistry factor determined using Kewaunee and Maine Yankee surveillance data.
4.1.2 Temperature Effects on Surveillance Data:
Studies have shown that for temperatures near 550 0F, a IF decrease in irradiation temperature will result in approximately 1IF increase in ARTNDT. Thus, for plants that use surveillance data from other reactor vessels that operate at a different temperature or when the capsule is at a different temperature than the plant, then this difference must be considered.
The temperature adjustment is as follows:
Temp. Adjusted ARTNDT = ARTNDT Measured + (Tcape - Tpi=)
As noted above, the D. C. Cook Unit 1 surveillance weld data will not be used since the heat differs from the vessel weld. Thus, for surveillance weld heat 13253, no temperature adjustments are necessary.
However, for vessel girth weld of heat 1P3571 surveillance data exists of the same heat from Kewaunee and Maine Yankee. Per DIT-B-02230-00171 the operating temperature differences were considered in determining the chemistry factor using the Kewaunee and Maine Yankee surveillance weld data.
D.C. Cook Unit 1 Heatup and Cooldown Limit Curves
4-3 Following in Table 4-1 are best estimate chemistry values for all the beltline materials, including the surveillance capsule weld along with the chemistry factors (CF) as determined per Regulatory Guide 1.99, Revision 2, Position I or 2 TABLE 4-1 Reactor Vessel Beltline Material Copper and Nickel Content and Calculated CF Material Description wt. % Cu(a) wt. % Ni(a) CF Intermediate Shell Plate B4406-1 0.12 0.52 81.4 Intermediate Shell Plate B4406-2 0.15 0.50 1 0 4 .5()
Intermediate Shell Plate B4406-3 0.15 0.49 1 0 4 (d)
Lower Shell Plate B4407-1 0.14 0.55 97.8 Lower Shell Plate B4407-2 0.12 0.59 82.8 Lower Shell Plate B4407-3 0.14 0.50 95.5 Intermediate Shell Axial Welds 0.21 0.873 208.7 (Heat 13253/12008)
Lower Shell Axial Welds (Heat 0.21 0.873 208.7 13253/12008)
Intermediate to Lower Shell Circ.
weld Seams 0.287 0.756 214(c)
(Heat 1 P3571)
Surveillance Weld Metal 0.27 0.74 206.4 (Heat 13253)
Surveillance Weld Metal 0.285 02 507 0.748211.9 (Heat 1 P3571 )(b)
NOTES:
(a) These values were determined by ATI and Transmitted to Westinghouse via DIT-B-02230-00,7].
(b) From Kewaunee and Maine Yankee (Reference DIT-B-02230-00171).
(c) The Chemistry Factor using Regulatory Guide 1.99, Rev. 2 Position 2.1 was determined to be 218.6'F per DIT-B-02230-00t 71 .
(d) The Chemistry Factor using Regulatory Guide 1.99, Rev. 2 Position 2.1 was determined to be 102.3.
D.C. Cook Unit I Heatup and Cooldown Limit Curves
4-4 Table 4-2 provides the calculation of the CF values for the surveillance materials per Regulatory Guide 1.99, Revision 2, Position 2.1.
TABLE 4-2 Calculation of Chemistry Factors using D.C. Cook Unit I Surveillance Capsule Data Material Capsule Fluenceca h) FF ARTm)T) I FF
- ARTj-T FF j Inter. Shell T 0267 0 641 60 38460 0.411 Plate B4406-3 X 0831 0.948 90 85.320 0899 (Longitudinal) Y 1.195 1.049 105 110.145 1.100 U 1.837 1.167 115 134.205 1.362 Inter. Shell T 0.267 0.641 70 44 870 0411 Plate B4406-3 X 0831 0948 110 104280 0.899 (Transverse) Y 1.195 1.049 115 120635 1.100 U 1 837 1.167 115 134.205 1.362 SUM: 772.120 7.544 CF = X(FF 2
- RTNDT) + Y( FF ) = (772.120) + (7.544) = 102.30F (a) Calculated Fluence values are in units of n/cm 2, E > 1.0 MeV.
(b) Data obtained from WCAP- 12483 Rev. 1141 , revised Capsule U Analysis.
D.C. Cook Unit I Heatup and Cooldown Limit Curves -
4-5 4.2 Surveillance Program Credibility Evaluation:
Regulatory Guide 1.99, Revision 2, describes general procedures acceptable to the NRC staff for calculating the effects of neutron radiation embrittlement of the low-alloy steels currently used for light water-cooled reactor vessels. Position C.2 of Regulatory Guide 1.99, Revision 2, describes the method for calculating the adjusted reference temperature and Charpy upper-shelf energy of reactor vessel beltline materials using surveillance capsule data. The methods of Position C.2 can only be applied when two or more credible surveillance data sets become available from the reactor in question.
To date there have been four surveillance capsules removed from D. C. Cook Unit 1. To use these surveillance data sets, they must be shown to be credible. In accordance with Regulatory Guide 1.99, Revision 2, there are five requirements that must be met for the surveillance data to be judged credible.
The purpose of this evaluation is to apply these credibility requirements to the reactor vessel surveillance data obtained from D. C. Cook Unit I and deteimine if these surveillance data sets are credible.
EVALUATION Criterion1: Materialsin the capsules shouldbe thosejudged most likely to be controlling, with regardto radiationembrittlement. The beltline region of the reactorvessel is defined in Appendix G to 10 CFR Part50, "FractureToughness Requirements", December 19, 1995 to be:
"the reactorvessel (shell materialincluding welds, heat affected zones, and plates orforgings)that directly surrounds the effective height of the active core and adjacent regions of the reactor vessel that are predicted to experiencesufficient neutron radiationdamage to be consideredin the selection of the most limiting material with regardto radiationdamage."
The D. C. Cook Unit I reactor vessel consists of the following beltline region materials:
Intermediate shell plates: B4406-1, B4406-2, and B4406-3, .
- Lower shell plates: B4407-1, B4407-2, and B4407-3,
- Intermediate shell axial welds: 2-442A, 2-442B, and 2-442C, heat 13253/12008 Linde 1092, Flux Lot 3791,
- Lower shell axial welds 3-442A, 3-442B, and 3-442C, heat 13253/12008, Linde 1092, Flux Lot 3791 and
- Intermediate to lower shell circumferential weld seam 9-442, heat 1P3571 Linde 1092, Flux Lot 3958.
D.C. Cook Unit I Heatup and Cooldown Limit Curves
4-6 Per WCAP-12483[ 4] the D. C. Cook Unit 1 surveillance program was based on ASTM E185-70, "Recommended Practice for Surveillance Tests on Structural Materials in Nuclear Reactors". Following is the evaluation of the selection of the D. C. Cook Unit 1 surveillance materials.
Weld metal:
The D. C. Cook Unit lsurveillance weld was fabricated with weld wire heat #13253. Since the Intermediate and Lower Shell longitudinal welds were fabricated with a tandem heat weld wire (13253/12008), the surveillance weld data from D. C. Cook Unit 1 is not applicable. No further credibility evaluations will be performed on heat 13253. It should be noted here, that surveillance data for weld heat 1P3571 is available from Kewuanee / Maine Yankee. Per DIT-B-02230-00t7 ] this data has been determined to be credible for use at D. C. Cook Unit 1.
Plates:
Intermediate Shell Plate B4406-2 and B4406-3 had the highest Cu content (0.15%) and the highest initial RTNDT values; therefore they were selected as the surveillance program base metal.
Therefore, the materials selected for use in the D. C. Cook Unit 1 surveillance program were those judged to be most likely controlling with regard to radiation embrittlement according to the accepted methodology at the time the surveillance program was developed. Based on engineering judgement the D. C. Cook Unit 1 surveillance program meets the intent of this criteria.
Criterion2: Scatter in the plots of Charpy energy versus temperaturefor the irradiatedand unirradiatedconditions should be small enough to permitthe determination of the 30ft-lb temperature and upper shelf energy unambiguously.
Plots of Charpy energy versus temperature for the unirradiated condition are presented in References 11, 12 and 13. Based on engineering judgement, the scatter in the data presented in those reports is small enough to determine the 30 ft-lb temperature and upper shelf energy of the D. C. Cook Unit 1 surveillance material unambiguously. Therefore, the D. C. Cook Unit 1 surveillance program meets this criteria.
D.C. Cook Unit 1Heeatup and Cooldown Limit Curves
4-7 Criterion3: When there are two or more sets of surveillance datafrom one reactor,the scatter of ARTNDr values abouta best-fit line draw'n as describedin RegulatoryPosition2.1 normally should be less than 280Ffor welds and 1 7 0Ffor base metaL Even ifthefluence range is large (two ormore orders of magnitude), the scattershould not exceed twice those values. Even if the datafail this criterionfor use in shift calculations,they may be credible "fordeterminingdecreasein upper shelf energy if the upper shelf can be clearly determined, following the definition'given in ASTME18S-82.;
The functional form of the least squares method as described in Regulatory Position 2.1 will be utilized to determine a best-fit line for this data and to determine if the scatter of these ARTNDT values about this 0
-line is less than 28 F for welds and less than 17'F for the plate.
Following is the calculation of the best fit line as described in Regulatory Position 2.1 of Regulatory Guide 1.99, Revision 2.
TABLE 4-3 DC Cook Unit 1 Surveillance Capsule Data .
Capsule Capsule f(a,b) FF(b) ARTNDT(a) FF*ARTNDT FF2 Material Inter. Shell Plate T 0.267 0.641 60 38.460 0.411 B4406-3 X 0.831 0.948 90 85.320 0.899 (Longitudinal)
Y 1.195 . .1.049 105 110.145 1.100 U 1.837 1.167 _ 115 134.205 1.362 Inter. Shell Plate T 0.267 0.641 70 44.870 0.411 B4406-3 0.831 '0.948 110 104.280 0.899 (Transverse)
Y 1.195 1.049 115 120.635 1.100 U 1.837 1.167 115 134.205 1.362 SUM:- 772.120 7.544 CFB44o6-3 = Y(FF
a) -Calculated Fluence values are in units of 10' 9n/cm2 , E > 1.0 MeV.
b) Data obtained from WCAP-12483 Rev. 1143, revised Capsule U Analysis., -
The scatter of ARTNIT values about the functional form of a best-fit line drawn as described in Regulatory Position 2.1 is presented in Table 4-4.
D.C. Cook Unit I Heatup and Cooldown Limit Curves -
4-8 TABLE 4-4 Best Fit Evaluation for DC Cook Unit 1 Surveillance Materials Base Matenal CF (OF) FF Measured Best Fit(a) Scatter of < 170 F (Base ARTNDT ARTNDr ARTNDT Metals)
(30 ft-lb) (OF) (OF) < 280F (Weld (OF) Metal)
Inter. Shell Plate 102.3 0.641 60 65.64 -5.64 Yes B4406-3 (Longitudinal) 102.3 0.948 90 97.08 -7.08 Yes 102.3 1.049 105 107.42 -2.42 Yes 102.3 1.167 115 119.50 -4.50 Yes Inter. Shell Plate 102.3 0.641 70 65.64 4.36 Yes B4406-3 (Transverse) 102.3 0.948 110 97.08 12.92 Yes 102.3 1.049 115 107.42 7.58 Yes 102.3 1.167 115 119.50 -4.50 Yes Notes:
(a) Best Fit Line Per Equation 2 of Reg. Guide 1.99 Rev. 2 Position 1.1.
Table 4-4 indicates that none of the eight measured plate ARTNDT values are outside of the Ia scatter band. Therefore, the plate data meet this criterion and the surveillance data is deemed credible.
Criterion4: The irradiationtemperatureof the Charpy specimens in the capsule should match the vessel wall temperature at the cladding/basemetal interface within +/- 250 F.
The D. C. Cook Unit I capsule specimens are located in the reactor between the thermal shield and the vessel wall and are positioned opposite the center of the core. The test capsules are in guide tubes attached to the thermal shields. The location of the specimens with respect to the reactor vessel beltline provides assurance that the reactor vessel wall and the specimens experience equivalent operating conditions such that the temperatures will not differ by more than 25°F. This engineering judgement is acceptable by the NRC.
D.C. Cook Unit 1 Heatup and Cooldown Limit Curves
4-9 Criterion5: The surveillancedatafor the correlationmonitor materialin the capsule shouldfall within the scatterband of the databasefor that material.
The D. C. Cook Unit 1 surveillance program does contain correlation monitor material. NUREG/CR 6413, ORNL/TM-13133 contains a plot of residual vs. Fast fluence for the correlation monitor material (Figure 11 of NUREG/CR-6413). The data used for this plot is contained in Table 14 (in the NUREG Report). The data found in the report contains the four capsules that have been removed and tested (T, X, Y & U), however since the time of the report the fluences values have been updated. Thus, Table 4-5 contains an updated calculation of Residual vs. Fast fluence.
Table 4-5 Calculation of Residual vs. Fast Fluence Capsule Fluence Fluence Factor Measured Shift RG 1.99 Shift Residual (Meas.
(X 10( 9 n/cm2 ) (FF) (CF*FF)(a) RG Shift)
T 0.267 0.641 60 81.4 -21.4 X 0.831 0.948 100 120.4 -20.4 Y 1.195 1.049 110 133.2 -23.2 U 1.837 1.167 120 148.2 -28.2 INote (a) Per NUREG/CR-6413, ORNUITM-13133, the Cu and Ni values for the Correlation Monitor Material is 0.170 Cu and 0.640 Ni. This equates to a Chemistry Factor of 127F from Reg. Guide 1.99 Rev. 2 Table 4-5 shows a 2 a uncertainty of less than 50c1F, which is the allowable scatter in NUREG/CR-6413, ORNL/TM-13133. Hence, this criteria is met.
Based on the preceding responses to the criteria of Regulatory Guide 1.99, Revision 2, Section B and the application of engineering judgement, the D. C. Cook Unit 1 surveillance data is credible.
D.C. Cook Unit 1 Heatup and Cooldown Limit Curves
4-10 4.2.1 Application of the Credibility Criteria:
The Kewaunee/Maine Yankee Surveillance weld data (Heat 1P3571) for use at D. C. Cook Unit I is deemed credible per Regulatory Guide 1.99, Revision 2. Hence, V/2GA will be used in the ART evaluations for the surveillance program materials.
4.2.2 Ga and How it was Determined:
Per Regulatory Guide 1.99, Revision, 2 Position 1.1, the values of yA are referred to as "28 0 F for welds and 170F for base metal, except that GyAneed not exceed 0.50 times the mean value of ARTNDT." The "mean value of ARTNDT" is defined in Regulatory Guide 1.99, Revision 2, by Equation 2. The chemistry factor in Regulatory Guide 1.99, Revision 2, Equation 2 is calculated from Tables 1 and 2 or Position 2.1 of Regulatory Guide 1.99, Revision 2.
Per Regulatory Guide 1.99, Revision, 2 Position 2.1, when there is credible surveillance data, GA is taken to be the lesser of 1/2 ARTNDT or 140F (280 F12) for welds, or 8.5 0 F (170 F/2) for base metal. ARTNDT again is defined herein by Equation 13, while utilizing a "Best-Fit Chemistry Factor" calculated in accordance with Position 2.1 of Regulatory Guide 1.99, Revision 2 and is shown herein on Table 4-1.
D.C. Cook Unit I Heatup and Cooldown Limit Curves
5-1 5.0 UNIRRADIATED PROPERTIES 5.1 Initial RTNDT of Beltline Materials Charpy V-notch impact specimens from the base material plates of the reactor vessel were machined in the longitudinal orientation (longitudinal axis of the specimen parallel to the major working direction of the plate) and the transverse orientation (longitudinal axis of the specimen perpendicular to the major working direction of the plate). The core region weld Charpy impact specimen was perpendicular to the weld direction. The notch of the weld metal Charpy specimen was machined such that the direction of crack propagation in the specimen was in the welding direction.
Table 5-1 contains a description of the beltline materials and their initial RTDr values.
TABLE 5-1 Reactor Vessel Material Initial RTNDT Material Description Heat # Flux Type Flux Lot Initial RTNDTP')
D. C. Cook Unit 1 Int. Shell Axial Welds 2-442A, 13253/12008 Linde 1092 3791 -560F B&C Intermediate Shell Plate B4406-1 C1260 -- 50F Intermediate Shell Plate B4406-2 C3506 - - 330F Intermediate Shell Plate B4406-3 C3506 .... 40°F Int/Lower Shell Circ. Weld 9-442 1P3571 Linde 1092 3958 -560F Lower Shell Axial Welds 13253/12008 Linde 1092 3791 -560F 3-442A, B&C Lower Shell Plate B4407-1 C3929 -- 280 F Lower Shell Plate B4407-2 C3932 -- -120F Lower Shell Plate B4407-3 C3929 - - 380F Closure Head Flange -... 60°F Vessel Flange .... 28 0F NOTES:
(a) The Initial RTNDT values were obtained from WCAP-12483141 are measured values for the plates and generic values for the welds.
D.C. Cook Unit 1 Heatup and Cooldown Limit Curves
5-2 5.2 Determination of al:
Since the initial RTNDT values are measured values, the D.C. Cook Unit I Tivalues are 0°F.
5.3 Bolt-up Temperature:
The minimum bolt-up temperature requirements for the D.C. Cook Unit I reactor pressure vessels are according to Paragraph G-2222 of the ASME Boiler and Pressure Vessel (B&PV) Code,Section XI, Appendix G, the reactor vessel may be bolted up and pressurized to 20 percent of the initial hydrostatic test pressure at the initial RTNDT of the material stressed by the bolt-up. Therefore, since the most limiting initial RTNDT value is 60°F (closure head flange), the reactor vessel can be bolted up at 60 0F.
D.C. Cook Unit I Heatup and Cooldown Limit Curves
6-1 6.0 REACTOR VESSEL GEOMETRIC & SYSTEM PARAMETERS 6.1 Reactor Vessel Physical Dimensions and Operating Conditions:
The following are the D.C. Cook Unit I reactor vessel physical dimensionsE143and operating conditions:
Reactor vessel inner diameter (to clad) = 173 inches Clad thickness = 7/32 inches Reactor Vessel Beltline Thickness = 8.5 inches Pre-Service System Hydrostatic Pressure = 3106 psig Capacity Factor (Future Cycles) = 90%
System and Component Operating Conditions/Dimensions:
Design Pressure = 2485 psig Operating Pressure = 2235 psig D.C. Cook Unit 1 Heatup and Cooldown Limit Curves
7-I 7.0 FLUENCE FACTOR DETERMINATION 7.1 Peak Clad Base Metal Interface Fluence for each Beltline Material:
Contained in Table 7-1 are the reactor vessel clad/base metal interface fluences. These values were obtained from WCAP-12483 Revision 1141,"Analysis of Capsule U from the American Electric Power Company D.C. Cook Unit 1 Reactor Vessel Radiation Surveillance Program".
TABLE 7-1 Calculated Fluence (10"9 n/cm2, E > 1.0 MeV) at the Pressure Vessel Clad/Base Metal Interface for the D.C. Cook Unit I Reactor Vessel EFPY 00 f 150 300 450 16.68 (EOC 17) 0.307 0.474 0.565 0.835 32 0.607 0.965- 1.204- 1.802 48 0.927 1.489 1.883 2.831 Per AEP the current end of license (EOL) EFPY is 32 EFPY and the EOL license renewal EFPY is 48 EFPY.
Thus, the EFPY values used to generate pressure/temperature curves and the calculated fluence values are:
Current EOL = 32 EFPY Renewal EOL = 48 EFPY D.C. Cook Unit I Heatup and Cooldown Limit Curves
7-2 7.2 1/4T & 3/4T Thickness Fluence for each Beltline Material:
The neutron fluence at the I/4T & 3/4T depth in the vessel wall was calculated per Regulatory Guide 1.99, Revision 2, as follows:
f= ff *{24(x), 1019 n/cm2 (E > 1.0 MeV) (10) where: f.f = Vessel inner wall surface fluence, 1019 n/cm2 (E > 1.0 MeV) (See Table 7-1) x = is the depth into the vessel wall from the inner surface, inches (0.25
- 8.5 inches or 0.75
- 8.5 inches)
Contained in Tables 7-2 and 7-3 is a summary of the fluence values used to calculate the D.C. Cook Unit 1 ART values used to develop the pressure-temperature curves for normal operation.
TABLE 7-2 Summary of Fluence Values Used to Calculate the D.C. Cook Unit 1 32 EFPY ART Values 3/4T 1/4T (n/cm ,E> 1.0 Surface Material (n/cm2 ,E > 1.0 MeV) (n/cm2 ,E > 1.0 MeV) ME>1 MeV)
Intermediate Shell Plate B4406-1 1.802 x 1019 1.082 x 1019 3.902 x 1018 Intermediate Shell Plate B4406-2 1.802 x 1019 1.082 x 1019 3.902 x 1018 Intermediate Shell Plate B4406-3 1.802 x 1019 1.082 x 1019 3.902 x 101' Lower Shell Plate B4407-1 1.802 x 1019 1.082 x 1019 3.902 x 1018 Lower Shell Plate B4407-2 1.802 x 10"9 1.082 x 1019 3.902 x 1018 Lower Shell Plate B4407-3 1.802 x 1019 1.082 x 1019 3.902 x 1018 Intermediate and Lower Shell Weld Longitudinal Weld Seams 1.204 x 10'9 0.723 x 1019 2.61 x 101 8 (Heat 13253/12008) (a)
Intermediate to Lower Shell Circ. Weld 19 19 18 Seams1.802 x 10 1.082 x 10 3.902x 10 NOTES:
(a) Intermediate and Lower Shell Weld Longitudinal Weld Seams are at the 300 location of the Core.
D.C. Cook Unit I Heatup and Cooldown Limit Curves
7-3 TABLE 7-3 Summary of Fluence Values Used to Calculate the D.C. Cook Unit 1 48 EFPY ART Values 3/4T Material Surface 1/4T (n/cm 2 ,E > 1.0 (n/cm 2 ,E > 1.0 MeV) (n/cm 2 ,E > 1.0 MeV) MeV)
Intermediate Shell Plate B4406-1 2.831 x 101 1.70 x 1019 6.13 x 1018 Intermediate Shell Plate B4406-2 2.831 x 10" 1.70 x 1019 6.13 x 1018 Intermediate Shell Plate B4406-3 2.831 x 1019 1.70 x 1019 6.13 x 1018 Lower Shell Plate B4407-1 2.831 x 10 9 1.70 x 1019 6.13 x 1018 Lower Shell Plate B4407-2 2.831 x 1019 1.70 x 10" 6.13 x 1018 Lower Shell Plate B4407-3 2.831 x 10' 1.70 x 10io 6.13 x 10i8 Intermediate and Lower Shell Weld Longitudinal Weld Seams 1.883 x 10"9 1.131 x 101" 4.077 x 1018 (Heat 13253/12008)(a) .......
Intermediate to Lower Shell Circ. weld 19 19 18 Seams (Heat 1P3571)
NOTES:
(a) Intermediate and Lower Shell Weld Longitudinal Weld Seams are at the 300 location of the Core.
7.3 Fluence Factors:
"ITefluence factors were calculated per Regulatory Guide 1.99, Revision 2, using the following equation.
2 FF = fluence factor'- f(-O. '0. log(o) (11)° where: f= Vessel inner wall surface fluence, 1/4 T fluence or 3/4T fluence,
[1019 n/cm2 (E> 1.0 MeV) + 10'9 n/cm 2 (E> 1.0 MeV)]
Contained in Tables 7-4 and 7-5 is a sumnmary of the calculated fluence factors for 32 and 48 EFPY respectively.
D.C. Cook Unit 1 Heatup and Cooldown Limit Curves
7-4 TABLE 7-4 Summary of Fluence Factors Used to Calculate the D.C. Cook Unit 1 32 EFPY ART Values 1/4T F 3/4T f Material (n/cm 2 E > 1.0 MeV) 1/4T FE (n/cm 2 E > 1.0 MeV) 3/4T FF Intermediate Shell Plate B4406-1 1.082 x 10"9 1.022 3.902 x 1018 0.739 Intermediate Shell Plate B4406-2 1.082 x 1019 1.022 3.902 x 1018 0.739 Intermediate Shell Plate B4406-3 1.082 x 1019 1.022 3.902 x 1018 0.739 Lower Shell Plate B4407-1 1.082 x 1019 1.022 3.902 x 1018 0.739 Lower Shell Plate B4407-2 1.082 x 1019 1.022 3.902 x 1018 0.739 Lower Shell Plate B4407-3 1.082 x 1019 1.022 3.902 x 1018 0.739 Intermediate and Lower Shell Weld Longitudinal Weld Seams 7.23 x 1018 0.909 2.61 x 1018 0.635 (Heat 13253/12008)
Intermediate to Lower Shell Circ. 3.902x 1018 0.739 weld Seams (Heat 1P3571)
TABLE 7-5 Summary of Fluence Factors Used to Calculate the D.C. Cook Unit 1 48 EFPY ART Values 1/4T F 3/4T f Material (n/cm2 E > 1.0 MeV) 1/4T FF (n/cm2 ,E > 1.0 MeV) 3/4T FE Intermediate Shell Plate B4406-1 1.70 x 1019 1.146 6.13 x 1018 0.863 Intermediate Shell Plate B4406-2 1.70 x 1019 1.146 6.13 x 1018 0.863 Intermediate Shell Plate B4406-3 1.70 x 10i 9 1.146 6.13 x 1018 0.863 Lower Shell Plate B4407-1 1.70 x 10"s 1.146 6.13 x 1018 0.863 Lower Shell Plate B4407-2 1.70 x 1019 1.146 6.13 x 1018 0.863 Lower Shell Plate B4407-3 1.70 x 1019 1.146 6.13 x 1018 0.863 Intermediate and Lower Shell Weld Longitudinal Weld Seams 1.131 x 10'9 1.034 4.077 x 1018 0.751 (Heat 13253/12008)
Intermediate to Lower Shell Circ. 19 1.146 6.13 x 101 0.863 weld Seams (Heat 1 P3571) 1 1 D.C. Cook Unit I Heatup and Cooldown Limit Curves
8-1 8.0 CALCULATION OF ADJUSTED REFERENCE TEMPERATURE
8.1 Methodology
From Regulatory Guide 1.99, Revision 2, the adjusted reference temperature (ART) for each material in the beltline region is given by the following expression:
ART = InitialRTNDT + A RTNDT + Margin (12)
Initial RTNDT is the reference temperature for the unirradiated material as defined in paragraph NB-2331 of Section II[ of the ASME Boiler and Pressure Vessel Coders]. If measured values of initial RTNEY for the material in question are not available, generic mean values for that class of material may be used if there are sufficient test results to establish a mean and standard deviation for the class.
ARTNDT is the mean value of the adjustment in reference temperature caused by irradiation and should be calculated as follows:
- f(O28- oo01o9 (13)
To calculate ARTmr at any depth (e.g., at 1/4T or 3/41), the following formula must first be used to attenuate the fluence at the specific depth. The resultant fluence is then placed in the equation above to calculate the ARTNDT at the specific depth. The calculated CF and FF values are given in Tables 4-1, 4-2, 7 4 and 7-5 of this report.
f(deptlx) = fsu-*ce* e(4) 24x) (14)
When there are "two or more credible surveillance data sets"'11 available, Regulatory Guide 1.99 Revision 2, Position 2.1, states "To calculate the Margin in this case, use Equation 4; the values given there for caA may be cut in half'. Equation 4 from Regulatory Guide 1.99 Revision 2, is as follows:
M = 24,+(15)
The values of aA are referred to as "28 0 F for welds and 170F for base metals."
Standard Deviation for Initial RTNDT Margin Term, o': If the initial RTNDT values are measured values, then caris taken to be 00F, otherwise use 170F.
Standard Deviation for ARTNDT Margin Term, ac: Per Regulatory Guide 1.99 Revision 2, Position 1.1, the values of a;, are referred to as "280 F for welds and 170F for base metal, except that a,&need not exceed 0.50 D.C. Cook Unit 1 Heatup and Cooldown Limit Curves
8-2 times the mean value of ARTNDT." The "mean value of ARTNfT" is defined in Regulatory Guide 1.99 Revision 2, by Equation 2. The chemistry factor in Regulatory Guide 1.99, Revision 2, Equation 2 is calculated from Tables 1 and 2 of Regulatory Guide 1.99 Revision 2.
Per Regulatory Guide 1.99, Revision 2, Position 2.1, when there is credible surveillance data, cA is taken to be the lesser of 1/22ARTDTr or 140F (28°F/2) for welds, or 8.5 0 F (17°F/2) for base metal. ARTNDT again is defined herein by Equation 4, while utilizing a "Best-Fit Chemistry Factor" calculated in accordance with Position 2.1 of Regulatory Guide 1.99, Revision 2.
Since m is taken to be zero when a heat-specific measured value of initial RTNDT are available (as they are in this case for the plate material), the total margin term, based on Equation 4 of Regulatory Guide 1.99, Revision 2, is as follows:
Position 1.1: Lesser of ARTNDT or 560F for Welds Lesser of ARTNrT or 34 0F for Base Metal Position 2.1: Lesser of ARTNDT or 28oF for Welds Lesser of ARTNDT or 170F for Base Metal 8.2 Adjusted Reference Temperature (ART) Calculations:
The ART calculations along with the actual margin terms used for D.C. Cook Unit 1 are listed in Tables 8-1 through 8-4.
D.C. Cook Unit 1 Heatup and Cooldown Limit Curves
8-3 TABLE 8-1 Calculation of the ART Values for D.C. Cook Unit 1 for the 1/4T Location and 32 EFPY Material RG 1.99 CF FF ARTNDT Margin IRTNDT ART R2 Method Intermediate Shell Plate
"'*B4406-1 Position 1.1 81.4 0F 1.022 83.2 0F 340F 50F 122 Intermediate Shell Plate Position 1.1 104.5 0F 1.022 106.8 0F 340F 330F 174 B4406-2 Position 2.1 102.3 0F 1.022- 104.6 0F 170F 330F 155 Intermediate Shell Plate Position 1.1 104OF 1.022 106.3 0F " 34 0F 40OF 180 B4406-3 Position 2.1 102.3 0F 1.022 104.6 0F 170F 40OF 162 LowerLoe Shell Plate 0Sel Position 1.1 97.80F 1.022 100.00 F B4407-1 34°F 28OF 162 LowerLower shell Plate Position 1.1 82.8 0F 1.022 84.60F 340F -120F B4407-2I 107 Lower Shell Plate Lower Position 1.1 95.50F 1.022 -
SB4407-3 97.60F 34 0F 38OF 170 Intermediate and Lower Shell Axial Weld Seams Position 1.1 208.7F 0.909 189.70 F 65.50 F -56F 199)
Intermediate to Lower Position 1.1 214OF 1.022 218.70F 65.50F -56 0F 228 Shell Circ. Weld Seams Position 2.1 218.6 0F 1.022 223.4 0F 440F -56 0F 211(2)
NOTES:
(a) The Intermediate to Lower Shell Circ. Weld Seam (Heat 1P3571) has the highest ART value. Since the material is a circumferential weld, less restrictive methodology can be used in generating PT curves.' However, the highest Axial Flaw must be checked with the more restrictive methodology. It should be noted that since the axial flaw ART's are so close to the circ. flaw ART's the axial flaw ART values will produce a more restrictive curve overall.
D.C. Cook Unit I Heatup and Cooldown Limit Curves -'
8-4 TABLE 8-2 Calculation of the ART Values for D.C. Cook Unit 1 for the 3/4T Location and 32 EFPY Material RG 1.99 CF FF ARTNDT Margin IRTNDT ART R2 Method Intermediate Shell Plate Position 1.1 81.4 0F .739 60.2 0F 340F 5OF 99 0F B4406-1 Intermediate Shell Plate Position 1.1 104.5 0F .739 77.20F 340F 330F 144 0F B4406-2 Position 2.1 102.3 0F .739 75.6OF 170F 330F 126 0F Intermediate Shell Plate Position 1.1 1040F .739 76.9OF 340F 40OF 1510F B4406-3 Position 2.1 102.3 0F .739 75.6OF 170F 40OF 1330F Lower Shell Plate Position 1.1 97.8 0F .739 72.3 0F 340F 28 0F 134 0F B4407-1 Lower shell Plate Position 1.1 82.80F .739 61.2 0F 340F -120F 830F B4407-2 Lower Shell Plate Position 1.1 95.50F .739 70.6°F 340F 38O1 1430F*a)
B4407-3 Intermediate and Lower Position 1.1 208.7 0F .635 132.5 0E 65.5 0F -560F 142 0F Shell Axial Weld Seams Intermediate to Lower Position 1.1 214OF .739 158.1 OF 65.5 0F -560F 168 0F Shell Circ. Weld Seams Position 2.1 218.6 0F .739 161.5 0F 44°F -560F 150oF("
NOTES:
(a) The Intermediate to Lower Shell Circ. Weld Seam (Heat 1P3571) has the highest ART value. Since the material is a circumferential weld, less restrictive methodology can be used in generating PT curves. However, the highest Axial Flaw must be checked with the more restrictive methodology. It should be noted that since the axial flaw ART's are so close to the circ. flaw ART's the axial flaw ART values will produce a more restrictive curve overall.
D.C. Cook Unit 1 Heatup and Cooldown Limit Curves
8-5 TABLE 8-3 Calculation of the ART Values for D.C. Cook Unit 1 for the 1/4T Location and 48 EFPY Material RG 1.99 CF FF -ARTNDT Margin IRTNDT ART R2 Method Intermediate Shell Plate Position 1.1 81.4 0F 1.146 93.3 0F 340F 50F 132 0F B4406-1 Intermediate Shell Plate Position 1.1 104.5 0F 1.146 119.8TF 34 0F 330F 1870F B4406-2 Position 2.1 102.3 0F -1.146 117.2 0F 170F 330F 167 0F Intermediate Shell Plate Position 1.1 104OF 1.146 119.20F 340F 40OF 1930F B4406-3 Position 2.1 1021.3F 1.146 117.20F 170F 40OF 174OF Lower Shell Plate Position 1.1 97.80F 1.146 112.1 0F 280F 34*F' 174 0F B4407-1 Lower shell Plate B4407-2 Position 1.1 82.80F 1.146 94.9 0F 340F -120F 1170F LowerLower Shell Plate -3 0 80 80 Position 1.1 95.50F 1.146 109.40F 34°F 380F 181OF B4407-3 Intermediate and Lower SnellnediatWelad Lerms Position 1.1 '208.7 0F 1.034 215.8 0F 65.5 0F -560F 22501"a' Shell Axial Weld Seams Intermediate to Lower Position 1.1 214 0F, 1.146 245.2 0F 65.5 0F -560F 255OF Shell Circ. Weld Seams Position 2.1 218.60F 1.146 250.50F 44°F -560F 2390F;a)
NOTES:
(a) The Intermediate to Lower Shell Circ. Weld Seam (Heat 1P3571) has the highest ART value. Since the material is a circumferential weld, less restrictive methodology can be used in generating PT curves. However, the highest Axial Flaw must be checked with the more restrictive methodology. It should be noted that since the axial flaw ART's are so close to the circ. flaw ART's the axial flaw ART values will produce a more restrictive curve overall.
D.C. Cook Unit 1 Heatup and Cooldown Limit Curves -
8-6 TABLE 8-4 Calculation of the ART Values for D.C. Cook Unit 1 for the 3/4T Location and 48 EFPY Material RG 1.99 CF FF ARTNDT Margin IRTNDT ART R2 Method Intermediate Shell Plate Position 1.1 81.4 0F .863 70.2 0F 340F 50F 109 0F B4406-1 Intermediate Shell Plate Position 1.1 104.5 0F .863 90.20F 340F 330 F 157 0F B4406-2 Position 2.1 102.3 0F .863 88.3 0F 170F 330F 138 0F Intermediate Shell Plate Position 1.1 1040F .863 89.8 0F 340F 40OF 164 0F B4406-3 Position 2.1 102.3 0F .863 88.30F 170F 40TF 145OF Lower Shell Plate Position 1.1 97.8 0F .863 84.40F 340F 280F 146 0F B4407-1 Lower shell Plate Position 1.1 82.80F .863 71.50F 340 F -120F 930F B4407-2 Lower Shell Plate Position 1.1 95.5 0F .863 82.4 0F 340F 380F 154 0F B4407-3 Intermediate and Lower Position 1.1 208.70F .751 156.7 0F 65.5 0F -560F 1660F(a)
Shell Axial Weld Seams Intermediate to Lower Position 1.1 214OF .863 184.7 0F 65.5 0F -560 F 194OF Shell Circ. Weld Seams Position 2.1 218.60F .863 188.70F 44-F -56OF 177°Fba)
NOTES:
(a) The Intermediate to Lower Shell Circ. Weld Seam (Heat IP3571) has the highest ART value. Since the material is a circumferential weld, less restrictive methodology can be used in generating PT curves. However, the highest Axial Flaw must be checked with the more restrictive methodology. It should be noted that since the axial flaw ART's are so close to the circ. flaw ART's the axial flaw ART values will produce a more restrictive curve overall.
D.C. Cook Unit 1 Heatup and Cooldown Limit Curves
8-7 Contained in Table 8-5 is a summary of the limiting ART values used in the generation of the D.C. Cook Unit 1 reactor vessel heatup and cooldown curves. It should be noted that the intermediate to lower shell girth weld (Heat #1P3571) has the highest overall ART values. However, since ASME Code Case N-641 (i.e. Code Case N-588) allows for less restrictive methodology when a circumferential weld has the highest ART, then the axial welds become limiting with the lower ART values and the traditional methodology from the 1996 version of the ASME Code, Appendix G.
TABLE 8-5 Summary of the Limiting ART Values to be Used in the Generation of the Cook Unit 1 Reactor Vessel Heatup and Cooldown Curves EFPY 1/4 T Limiting ART 3/4 Limiting ART Circumferential Flaw 32 211OF 150OF 48 239 0 F 177 0F Axial Flaw 32 199 0F 143 0F*
48 225°F 166 0F
- Beltline Weld Seams (Axial. Weld) are the limiting materials for all cases except 32 EFPY 3/4T, which is Lower Shell Plate B4407-3 limited.
D.C. Cook Unit 1 Heatup and Cooldown Limit Curves
9-1 9.0 HEATUP AND COOLDOWN PRESSURE-TEMPERATURE LIMIT CURVES 9.1 Introduction and Methodology:
Pressure-temperature limit curves for normal heatup and cooldown of the primary reactor coolant system have been calculated for the pressure and temperature in the reactor vessel belthne region using the methods discussed in Sections 3 and 8 of this report.
Figure 9-1 presents the heatup curves without margins for possible instrumentation errors for a heatup rate of 600 F/hr. This curve is applicable to 32 EFPY (current end of license). Figure 9-2 presents the cooldown curves without margins for possible instrumentation errors for cooldown rates of 0, 20, 40, 60, and 100 0F/hr. These curves are also applicable to 32 EFPY (current end of license). Figure 9-3 presents the heatup curves without margins for possible instrumentation errors for a heatup rates of 60°F/hr: This curve is -applicable to 48 EFPY (end of license renewal). Figure 9-4 presents 'the cooldown curves without margins for possible instrumentation errors for cooldown rates of 0, 20, ,40, 60, and IOO 0 F/hr. These curves are also applicable to 48 EFPY (end-of license renewal). Allowable combinations of temperature and pressure for specific temperature change rates are below and to the right of the limit lines shown in Figures 9-1 through 9-4. This is in addition to other criteria, which must be met before the reactor is made critical, as discussed in the following paragraphs.
The reactor must not be made critical until pressure-temperature combinations are to the right of the criticality limit line shown in Figures 9-1 and 9-3. The straight-line portion of the criticality limit is at the minimum permissible temperature for the 2485 psig inservice hydrostatic test as required by Appendix G to 10 CFR Part 50. The governing equation for the hydrostatic test is defined in Code Case N-640[sl and Appendix G to Section XI of the ASME Code(31 as follows:
1.5 Ki,, < Ki,- (15)
- where, Kim is the stress intensity factor covered by membrane (pressure) stress, Ki,= 33.2 + 20.734 exp [0.02 (T - RTNDtrr)],
T is the minimum permissible metal temperature, and RTNDT is the metal reference nil-ductility temperature D.C. Cook Unit I Heatup and Cooldown Limit Curves
9-2 The criticality limit curve specifies pressure-temperature limits for core operation to provide additional margin during actual power production as specified in Reference 2. The pressure-temperature limits for core operation (except for low power physics tests) are that the reactor vessel must be at a temperature equal to or higher than the minimum temperature required for the inservice hydrostatic test, and at least 40°F higher than the minimum permissible temperature in the corresponding pressure-temperature curve for heatup and cooldown calculated as described in Section 3 of this report. For the heatup and cooldown curves without margins for instrumentation errors, the minimum temperature for the in service hydrostatic leak tests for D.C. Cook Unit I reactor vessel at 32 and 48 EFPY is 259 0 F and 285 0F, respectively. The vertical line drawn from these points on the pressure-temperature curve, intersecting a curve 40OF higher than the pressure-temperature limit curve, constitutes the limit for core operation for the reactor vessel.
Figures 9-1 through 9-4 define all of the above limits for ensuring prevention of nonductile failure for the D.C. Cook Unit I reactor vessel. The data points for the heatup and cooldown pressure-temperature limit curves shown in Figures 9-1 through 9-4 are presented in Tables 9-1 through 9-4.
D.C. Cook Unit I Heatup and Cooldown Limit Curves
9-3 MATERIAL PROPERTY BASIS LIMITING MATERIAL: Intermediate Shell Axial Weld (Heat 13253/12008)
& Lower Shell Plate B4407-3 LIMrTING ART VALUES AT 32 EFPY: 1/4T, 199°F 3/4T, 143°F 2500 Operlim Version 532 ILeak Test Limitý 2250 Unacceptabl-e Acceptable 2000 OperationJ- _ Operation Heatup Rate [ 'Critical Limit[
60 Deg. FIHr 60 Deg. FIHr 1750
- c. 1500 0)
P 1250 IL.
"0o
=5 U
1000 750 Criticality Limit based on 500 -1" Inservice hydrostatic test temperature (259 F) for the service period up to 32 EFPY
-A,*I" I 250 0 50 100 150 200 250 -300 350 400 450 500 550 Moderator Temperature (Deg. F)
FIGURE 9-1 ' D.C. Cook Unit 1 Reactor Coolant System Heatup Limitations (Heatup Rate of 600F/hr) Applicable for 32 EFPY (Without Margins for Instrumentation Errors)
(Includes Vessel Flange Requirements of 180°F and 621 psi per 10CFR50)
D.C. Cook Unit 1 Heatup and Cooldown Limit Curves
9-4 MATERIAL PROPERTY BASIS LIMTITING MATERIAL: Intermediate Shell Axial Weld (Heat 13253/12008)
& Lower Shell Plate B4407-3 LIMITING ART VALUES AT 32 EFPY: 1/4T, 199 0F 3/4T, 143 0 F 2500 Operlim Version 5.1 Run 13828 2250 Unacceptable 2000 Operation- ,Acceptable Operation 1750 C. 1500 m
U 1250 Cooldown - , _ _
Rates FIHr 0 'steady-state
" 1000 -20 " _
(a -40
-60
-100 750" Boltup 250 Tam.
0 0 50 100 150 200 250 300 350 400 450 500 550 Moderator Temperature (Deg. F)
FIGURE 9-2 D.C. Cook Unit 1 Reactor Coolant System Cooldown Limitations (Cooldown Rates of 0, 20, 40, 60 and 100F/hr) Applicable for 32 EFPY (Without Margins for Instrumentation Errors) (Includes Vessel Flange Requirements of 180°F and 621 psi per 10CFR50)
D.C. Cook Unit 1 Heatup and Cooldown Limit Curves
9-5 MATERIAL PROPERTY BASIS LIMITING MATERIAL: Intermediate Shell Axial Weld (Heat 13253/12008)
LIM1TING ART VALUES AT 48 EFPY: 1/4T, 2250 F 3/4T, 166 0F 2500 Operlimn ersion*5.1 Run 22523 Leak T Limit 2250 200.._Unacceptable Accept 2000 Operation Opera, Heatup Rate Critical Limit 1750 60 Deg. F/Hr 60 Deg. FIHr 1500 2
0.2 1250 ,
"(U 75 Criticality Limit based on Inservice hydrostatic test "500 FA 250 _ I temperature (285 F)for the IBoitup-;o-- service period up to 48 EFF 250
- I~~emp-.l'-
0 0 50 100 150 200 250 300 ,350 400 450 500 550 Moderator Temperature (Deg. F)
FIGURE 9-3 D.C. Cook Unit 1 Reactor Coolant System Heatup Limitations (Heatup, Rate of 60(F/hr) Applicable for 48 EFPY (Without Margins for Instrumentation Errors)
(Includes Vessel Flange Requirements of 180OF and 621 psi per IOCFR50)
D.C. Cook Unit 1 Heatup and Cooldown Limit Curves " -
9-6 MATERIAL PROPERTY BASIS LIMITING MATERIAL: Intermediate Shell Axial Weld (Heat 13253/12008)
LIMITING ART VALUES AT 48 EFPY: 1/4T, 225-F 3/4T, 166°F 2500 "opertmn version 5 1 Run 22523 2250 Unacceptable _Acceptable 2000 H Operaton -Operation 1750 01500 2 1250 C.
Cooldown Rates
" 1000-
.2 FIHr steady-state C, -20
-40 750 -60
-100 500 250 1 iBolt_
0 0 50 100 150 200 250 300 350 400 450 500 550 Moderator Temperature (Deg. F)
FIGURE 9-4 D.C. Cook Unit 1Reactor Coolant System Cooldown Limitations (Cooldown Rates of 0, 20, 40, 60 and 100°F/hr) Applicable for 48 EFPY (Without Margins for Instrumentation Errors) (Includes Vessel Flange Requirements of 180°F and 621 psi per 10CFR50)
D.C. Cook Unit I Heatup and Cooldown Limit Curves __
9-7 TABLE 9-1 D.C. Cook Unit 1 Reactor Vessel Heatup Curve Data Points for 32 EFPY Without Margins for Instrumentation Errors (Includes Vessel Flange Requirements of 180°F and 621 psi per IOCFR50) 60°F/hr. Heatup 60°F/hr. Criticality -Leak Test Limit T (OF) P (psig) T (OF) P (psig) T (OF) P (psig) 60 0 259 0 242 2000 60 621 259 621 259 *2485 621 259 621 65 70 621 259 621 75 621 259 621 80 621 259 621 85 621 259 621 90 621 259 621 95 621 259 621 100 621 259 621 105 621 259 621 110 621 259 621 115 621 259 621 120 621 259 621 125 621 259 621 130 621 259 621 135 621 259 621 140 621 259 621 145 621 259 621 150 621 259 621 155 621 259 621 160 621 259 621 165 621 259 621 170 621 259 621 175 621 259 621 180 621 259 860 180 621 259 887 180 860 259 917 185 887. 259 950 190 917 259 987 D.C. Cook Unit I Heatup and Cooldown Limit Curves
9-8 195 950 259 1027 200 987 259 1072 205 1027 259 1121 210 1072 260 1175 215 1121 265 1236 220 1175 270 1290 225 1236 275 1345 230 1290 280 1406 235 1345 285 1473 240 1406 290 1547 245 1473 295 1628 250 1547 300 1718 255 1628 305 1817 260 1718 310 1926 265 1817 315 2047 270 1926 320 2180 275 2047 325 2327 280 2180 285 2327 D.C. Cook Unit I Heatup and Cooldown Limit Curves
9-9 U TABLE 9-2 D.C. Cook Unit I Rea&tor Vessel Cooldown Curve Dath Points for 32 EFPY Without Margins for Instrumentation Errors (Includes Vessel Flange Requirements of 180°F and 621 psi per I OCFR50)
Steady State 20 OF/hr. 40oF/hr. 60oF/hr. - 100oF/hr.
T(°F) P (psig) T(°F) P (psig) T(OF) P (psig) T(OF) P (psig) T(OF) P (psig) 60 0 60 '0 60 0 60 0 60 0 60 621 .60 578 60 530 60 480 60 377 65 621 65 581 65 -532 65 482 65 380 70 621 70 584 70 535 70 485 70 383 75 621 75 587 75 538 75 489 -75 387 80 621 80 590 80 542 80 492 -80 391 85 621 85 594 °85 546 85 497 85 396 90 621 90 598 90 550 90 501 90 401 95 621 95 603 95 555 95 507 95 408 100 621 100 608 100 561 100 513 100 415 105 621 105 614 105 567 105 519 105 422 110 621 110 620 110 574 110 527 110 431 115 621 115 621 115 581 115 535 115 441 120 621 120 621 120 590 120 544 120 452 125 621 125 621 125 600 125 555 125 465 130 621 130 621 130 610 130 566 130 478 135 621 135 621 135 621 135 579 135 494 140 621 140 621 140 621 140 593 140 511 145 621 145 621 145 621 145 609 145 530 150 621 150 621 150 621 150 621 150 552 155 621 155 621 155 621 155 621 155 576 160 621 160 621 160 621 160 621 160 602 165 621 165 621 165 621 165 621 165 621 170 621 170 621 170 621 170 621 170 621 175 621 175 621 175 621 175 621 175 621 180 621 180 621 180 621 180 621 180 621 180 860 180 831 180 805 180 780 180 741 185 887 185 861 185 838 185 817 185 786 190 917 190 894 190 874 190 857 190 836 195 950 195 931 195 914 195 902 195 891 200 987 200 971 200 959 200 951 200 951 205 1027 205 1015 205 1008 205 1006 205 1006 210 1072 210 1065 210 1063 210 1063 210 1063 D.C. Cook Unit I Heatup and Cooldown Limit Curves
9-10 215 1121 215 1119 215 1119 215 1119 215 1119 220 1175 220 1175 220 1175 220 1175 220 1175 225 1236 225 1236 225 1236 225 1236 225 1236 230 1302 230 1302 230 1302 230 1302 230 1302 235 1376 235 1376 235 1376 235 1376 235 1376 240 1457 240 1457 240 1457 240 1457 240 1457 245 1547 245 1547 245 1547 245 1547 245 1547 250 1646 250 1646 250 1646 250 1646 250 1646 255 1756 255 1756 255 1756 255 1756 255 1756 260 1877 260 1877 260 1877 260 1877 260 1877 265 2012 265 2012 265 2012 265 2012 265 2012 270 2160 270 2160 270 2160 270 2160 270 2160 275 2323 275 2323 275 2323 275 2323 275 2323 D.C. Cook Unit I Heatup and Cooldown Limit Curves
I I tiý t-9-11 TABLE 9-3 D.C. Cook Unit I Reactor Vessel Heatup Curve Data Points for 48 EFPY Without Margins for Instrumentation Errors (Includes Vessel Flange Requirements of 180°F and 621 psi per I0CFR50) 60°F/hr. Heatup 6 0 °F/hr. Criticality Leak Test Limit 0 0 T( F) P (psig) T( F) P (psig) T(°F) P (psig) 60 0 285 0 268 2000 60 592 285 592 285 2485 65 592 285 '592 70 592 '285- 593 75 592 285 593 80 592 285 596 85 592 285 597 90 592 285 '600 95 592 285 603 100 592 285 606 105 593 285. 611 110 596 '285 612 115 600 285 620 120 606 285 621 125 612 285 621 130 620 285 621 135 621 285 -621 140 621 285 -621 145 621 285 621 150 621 285 621 155 621 285 621 160 621 285 621 165 621 285 621 170 621 285 621 175 621 285 621 180 621 285 756 180 756 285 772 185 772 285 789 190 789 285 809 195 809 285 831 D.C. Cook Unit I Heatup and Cooldown Limit Curves
9-12 200 831 285 855 205 855 285 881 210 881 285 911 215 911 285 943 220 943 285 979 225 979 285 1019 230 1019 285 1062 235 1062 285 1111 240 1111 285 1164 245 1164 290 1223 250 1223 295 1281 255 1281 300 1335 260 1335 305 1394 265 1394 310 1459 270 1459 315 1531 275 1531 320 1610 280 1610 325 1698 285 1698 330 1795 290 1795 335 1901 295 1901 340 2019 300 2019 345 2149 305 2149 350 2292 310 2292 355 2450 315 2450 D.C. Cook Unit I Heatup and Cooldown Limit Curves
9-13 TABLE 9-4 D.C. Cook Unit I Reactor Vessel Cooldown Curve Data Points for 48 EFPY Without Margiing for Instrum entation Errors (Includes Vessel Flange Requirements of 180°F and 621 psi pet IOCFR50)
SSteady State- 20 oF/hr:- , 40OF/hr. 60oF/hr. --- ' -100oF/hr.
-T( 0 F) P (psig)- T(0 F) P (psig) T(oF) - P (psig) T(OF) P (psig) T(oF) P (psig) 60 0 - 0 60 0 60 .0 60 -0 60 616 60 568 60 518 60 -467 60 362 65 618 65 569 65 520 65" 469 65- 363 70 620 "70 571 70 521 70 470 -70 364 75 621 75 573 75 523- 75 472 75 366 80 621 --80 575 80 525 80 474 80 368 85 621 85 577 -85 527 85 476 " - 85 371 90- 621 90 579 90 529 90 479 90- 373 95 621 - 95 582 95 532 95 -481- 95 .377 100 621 100-° 585 100 535 100 485 -. 100 380 105 621 105 588 -539
-105 105 488 --105 -384
- 110 .621 110 592 110 ", 543 - 110- 492 -110 -389 115 621 115 596 115 547 - 115 497 -115 395 120 621 120 601 120 552 120 502 120 401 125 621 125 606 125 557 125 508 125 408 130 621 130 612 130 563 130 515 130 415 135 621 135 618 135 570 135 522 135 424 140 621 140 621 140 578 140 530 140 434 145 621 145 621 145 586 145 539 145 445 150 621 150 621 150 595 150 549 150 457 155 621 155 621 155 606 155 561 155 471 160 621 160 621 160 617 160 573 160 486 165 621 165 621 165 621 165 587 165 503 170 621 170 621 170 621 170 603 170 522 175 621 175 621 175 621 175 620 175 543 180 621 180 621 180 621 180 621 180 566 180 756 180 716 180 677 180 639 185 593 185 772 185 734 185 697 185 660 190 622 190 789 190 753 190 718 190 684 195 654 195 809 195 775 195 742 195 710 200 690 200 831 200 799 200 768 200 739 205 730 205 855 205 825 205 797 205 772 210 774 D.C. Cook Unit I Heatup and Cooldown Limit Curves
9-14 210 881 210 854 210 829 210 807 215 824 215 911 215 887 215 865 215 847 220 878 220 943 220 922 220 905 220 891 225 939 225 979 225 962 225 949 225 940 230 993 230 1019 230 1006 230 997 230 993 235 1051 235 1062 235 1054 235 1051 235 1051 240 1108 240 1111 240 1108 240 1108 240 1108 245 1164 245 1164 245 1164- 245 1164 245 1164 250 1223 250 1223 250 1223 250 1223 250 1223 255 1288 255 1288 255 1288 255 1288 255 1288 260 1361 260 1361 260 1361 260 1361 260 1361 265 1440 265 1440 265 1440 265 1440 265 1440 270 1528 270 1528 270 1528 270 1528 270 1528 275 1626 275 1626 275 1626 275 1626 275 1626 280 1733 280 1733 280 1733 280 1733 280 1733 285 1852 285 1852 285 1852 285 1852 285 1852 290 1984 290 1984 290 1984 290 1984 290 1984 295 2129 295 2129 295 2129 295 2129 295 2129 300 2289 300 2289 300 2289 300 2289 300 2289 305 2467 305 2467 305 2467 305 2467 305 2467 D.C. Cook Unit I Heatup and Cooldown Limit Curves
10-1 10.0 ENABLE TEMPERATURE CALCULATION:
10.1 ASME Code Case N-641 Methodology:
ASME Code Case N-641 9] presents alternative procedures for calculating pressure-temperature relationships and low temperature overpressure protection (LTOP) system effective temperatures and allowable pressures. "These procedures take into account alternative fracture toughness properties, circumferential and axial reference flaws, and plant-specific LTOP effective temperature calculations."
ASME Code Case N-641 provides the following temperature condition to protect against failure during reactor startup and shutdown. The code requires that the LTOP or COMS system be effective at coolant temperatures less than 200OF or at coolant temperatures less than a temperature corresponding to a reactor vessel metal temperature calculated below:
(1) T. = RTNDT + 40 + max (ATt.1), OF (2) T, = RTNDT + 50 In [((F
- Mm (pRi / t)) - 33.2) / 20.734], OF, where, Mm = 0.926(t)Or2), for an inside surface flaw (Ref. 3),
F = 1.1, accumulation factor for safety relief valves (Ref. 9) p = 2.485, vessel design pressure, ksi (Section 6.1)
R, = 173 /2 = 86.5, vessel inner radius, in. (Section 6.1) t = 8.5, vessel wall thickness, in. (Section 6.1)
RTNDT is the highest adjusted reference temperature (ART) for the limiting beltline material at a distance one fourth of the vessel section thickness from the vessel inside surface (ie. clad/base metal interface), as determined by Regulatory Guide 1.99, Revision 2. The highest of the three temperatures determines the LTOP system effective temperature 10.2 32 EFPY Enable Temperature:
The highest calculated l/4T ART of the critical material for the D.C. Cook Unit 1 reactor vessel beltline regions at 32 EFPY is 199 0F.
From the OPERLIM computer code output for the D.C. Cook Unit 1 32.EFPY Pressure-Temperature limit curves without margins the maximum ATm, is:
Cooldown Rate (Steady-State Cooldown):
max (AT,,t,1) at l14T = 0°F Heatup Rate of 60°F/Hr:
max (AT .t.m) at l14T 17.902°F D.C. Cook Unit 1 Heatup and Cooldown Limit Curves
10-2 Enable Temperature, Te (1) = RTNDT + 40 + max (ATmntl), IF
= (199 + 40 + 17.902) IF
= 256.902oF Enable Temperature, Te (2) = RTNDT + 50 ln[((F
- Mm (pR, / t)) -33.2) / 20.734], OF
= 199 + 50 ln[((1.1 * .926(8.5)(1")* 2.485
- 86.5 / 8.5)-33.2) / 20.734], IF
= 199 + 50 ln[41.90 / 20.734], OF
= 199 + 50 1n[2.021]
= 234.180 0 F The minimum required enable temperature for the D.C. Cook Unit 1 Reactor Vessels will be conservatively chosen to be 260°F for 32 EFPY.
10.3 48 EFPY Enable Temperature:
The highest calculated l/4T ART of the critical material for the D.C. Cook Unit 1 reactor vessel beltline regions at 48 EFPY is 2250 F.
From the OPERLIM computer code output for the D.C. Cook Unit 1 48 EFPY Pressure-Temperature limit curves without margins the maximum ATm1tt is:
Cooldown Rate (Steady-State Cooldown):
max (ATnt.) at 1/4T = 0°F Heatup Rate of 600F/IIr:
max (AT,,m) at 1/4T = 17.9020 F Enable Temperature (ENBT) = RTqDT + 40 + max (ATnt,), OF
= (225 + 40 + 17.902) OF
= 282.902oF Enable Temperature, T. (2) = RTNDT + 50 ln[((F
- Mm (pRi / t)) - 33.2) / 20.734], OF
= 225 + 50 ln[((1.1 * .926(8.5) (1)
- 2.485
- 86.5 / 8.5)-33.2) / 20.734], IF
= 225 + 50 ln[41.90 / 20.734], OF
= 225 + 50 ln[2.021]
= 260.180oF The minimum required enable temperature for the D.C. Cook Unit 1 Reactor Vessels will be conservatively chosen to be 285°F for 48 EFPY.
D.C. Cook Unit I Heatup and Cooldown Limit Curves
11-1
11.0 REFERENCES
1 Regulatory Guide 1.99, Revision 2, "Radiation Embrittlement of Reactor Vessel Materials", U.S.
'Nuclear Regulatory Commission, May, 1988.
2 10 CFR Part 50, Appendix G, "Fracture Toughness Requirements", Federal Register, Volume 60, No. 243, dated December 19, 1995.
3 ASME Boiler and Pressure Vessel Code,Section XI, "Rule for Inservice Inspection of Nuclear Power Plant Components", Appendix G, "Fracture Toughness Criteria for Protection Against Failure", December 1995.
4 WCAP-12483, Revision 1, "Analysis of Capsule U from the Indiana Michigan Power Company D.C. Cook Unit 1 Reactor Vessel Radiation Surveillance Program", J. H. Ledger & E. T. Hayes, dated December 2002.
5 1989 Section III, Division 1 of the ASME Boiler and Pressure Vessel Code, Paragraph NB-2331, "Material for Vessels".
6 WCAP-14040-NP-A, Revision 2, "Methodology used to Develop Cold Overpressure Mitigating System Setpoints and RCS Heatup and Cooldown Limit Curves", J. D. Andrachek, et al., January 1996.
7 AEP Design Information Transmittal (DIT), DIT-B-02230-00, "Material Chemistry of the Reactor Vessel Belt-line Materials for Cook Nuclear Plant Units I & 2", T.Satyan-Sharma, 10/23/01.
8 Cases of ASME Boiler and Pressure Vessel Code, Case N-640, "Alternative Reference Fracture Toughness for Development of P-T Limit Curves for Section XI, Division 1", Approved March 1999.
9 Cases of ASME Boiler and Pressure Vessel Code, Case N-641, "Alternative Pressure Temperature Relationship and Low Temperature Overpressure Protection System Requirements," Approved 03/99.
10 Cases of ASME Boiler and Pressure Vessel Code, Case N-588, "Attenuation of Reference Flaw Orientation of Appendix G for Circumferential Welds in Reactor Vessels",Section XI, Division 1, Approved December 12, 1997.
11 "Reactor Vessel Material Surveillance Program for Donald C. Cook Unit No. 1 Analysis of Capsule T," Final Report SWRI Project 02-4770, December 1977.
D.C. Cook Unit 1 Heatup and Cooldown Limit Curves
11-2 12 "Reactor Vessel Material Surveillance Program for Donald C. Cook Unit No. 1 Analysis of Capsule X," Final Report SWRI Project 02-6159, June 1981.
13 "Reactor Vessel Material Surveillance Program for Donald C. Cook Unit No. 1 Analysis of Capsule Y," Final Report SWRI Project 06-7244-00 1, January 1984.
14 Combustion Engineering Drawing No. 233-440 "General Arrangement - Elevation" D.C. Cook Unit I Heatup and Cooldown Limit Curves
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