NL-21-0483, Cycle 31 Core Operating Limits Report

Cycle 31 Core Operating Limits Report

ML21137A185
Person / Time
Site:	Farley
Issue date:	05/14/2021
From:	Gayheart C Southern Nuclear Operating Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NL-21-0483
Download: ML21137A185 (18)

Text

Cheryl A. Gayheart Regulatory Affairs Director 3535 Colonnade Parkway Birmingham, AL 35243 205 992 5316 tel 205 992 7601 fax cagayhea@southernco.com May 14, 2021 Docket No.:

50-348 NL-21-0483 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Joseph M. Farley Nuclear Plant - Unit 1 Cycle 31 Core Operating Limits Report Ladies and Gentlemen:

In accordance with Technical Specification 5.6.5.d, Southern Nuclear Operating Company (SNC) submits the enclosed Core Operating Limits Report (COLR) for the Joseph M.

Farley Nuclear Plant (FNP) - Unit 1 Cycle 31 Version 1.

This letter contains no NRC commitments. If you have any questions, please contact Jamie Coleman at 205.992.6611.

Respectfully submitted, Cheryl A. Gayheart Regulatory Affairs Director CAG/was

Enclosure:

Core Operating Limits Report for FNP Unit 1 Cycle 31 Version 1 cc: Regional Administrator, Region ll NRR Project Manager - Farley Nuclear Plant Senior Resident Inspector - Farley Nuclear Plant RTYPE: CFA04.054

Joseph M. Farley Nuclear Plant - Unit 1 Cycle 31 Core Operating Limits Report Enclosure Core Operating Limits Report for FNP Unit 1 Cycle 31 Version 1

Joseph M. Farley Nuclear Plant Core Operating Limits Report Unit 1 - Cycle 31 Version 1 December 2020

CORE OPERATING LIMITS REPORT, FNP UNIT 1 CYCLE 31 December 2020 Page 1 of 15 1.0 CORE OPERATING LIMITS REPORT This Core Operating Limits Report (COLR) for FNP UNIT 1 CYCLE 31 has been prepared in accordance with the requirements of Technical Specification 5.6.5.

The Technical Requirement affected by this report is listed below:

13.1.1 SHUTDOWN MARGIN - MODES 1 and 2 (with keff 1)

The Technical Specifications affected by this report are listed below:

2.1.1 Reactor Core Safety Limits for THERMAL POWER 3.1.1 SHUTDOWN MARGIN - MODES 2 (with keff < 1), 3, 4 and 5 3.1.3 Moderator Temperature Coefficient 3.1.5 Shutdown Bank Insertion Limits 3.1.6 Control Bank Insertion Limits 3.2.1 Heat Flux Hot Channel Factor - ()

3.2.2 Nuclear Enthalpy Rise Hot Channnel Factor -

3.2.3 Axial Flux Difference 3.3.1 Reactor Trip System Instrumentation Overtemperature T (OTT) and Overpower T (OPT) Setpoint Parameter Values for Table 3.3.1-1 3.4.1 RCS DNB Parameters for Pressurizer Pressure, RCS Average Temperature, and RCS Total Flow Rate 3.9.1 Boron Concentration

CORE OPERATING LIMITS REPORT, FNP UNIT 1 CYCLE 31 December 2020 Page 2 of 15 2.0 OPERATING LIMITS The cycle-specific parameter limits for the specifications listed in Section 1.0 are presented in the following subsections. These limits have been developed using NRC approved methodologies as specified in Technical Specification 5.6.5.

2.1 SHUTDOWN MARGIN - MODES 1 and 2 (with keff 1.0) (Technical Requirement 13.1.1) 2.1.1 The SHUTDOWN MARGIN shall be greater than or equal to 1.77 percent k/k.

2.2 SHUTDOWN MARGIN - MODES 2 (with keff < 1.0), 3, 4 and 5 (Specification 3.1.1) 2.2.1 Modes 2 (keff < 1.0), 3 and 4 - The SHUTDOWN MARGIN shall be greater than or equal to 1.77 percent k/k.

2.2.2 Mode 5 - The SHUTDOWN MARGIN shall be greater than or equal to 1.0 percent k/k.

CORE OPERATING LIMITS REPORT, FNP UNIT 1 CYCLE 31 December 2020 Page 3 of 15 2.3 Moderator Temperature Coefficient (Specification 3.1.3) 2.3.1 The Moderator Temperature Coefficient (MTC) limits are:

The BOL/ARO-MTC shall be less than or equal to +0.7 x 10-4 k/k/°F for power levels up to 70 percent RTP with a linear ramp to 0 k/k/°F at 100 percent RTP.

The EOL/ARO/RTP-MTC shall be less negative than -4.3 x 10-4 k/k/°F.

2.3.2 The MTC Surveillance limits are:

The 300 ppm/ARO/RTP-MTC should be less negative than or equal to

-3.65 x 10-4 k/k/°F.

The revised predicted near-EOL 300 ppm MTC shall be calculated using Figure 5 and the following algorithm:

Revised Predicted MTC = Predicted MTC* + AFD Correction** + Predictive Correction***

where,

• Predicted MTC is calculated from Figure 5 at the burnup corresponding to the measurement of 300 ppm at RTP conditions,

• • AFD Correction is the more negative value of:

{0 pcm/°F or (AFD

• AFD Sensitivity)}

where: AFD is the measured AFD minus the predicted AFD from an incore flux map taken at or near the burnup corresponding to 300 ppm, AFD Sensitivity = 0.07 pcm/°F / AFD

• • • Predictive Correction is -3 pcm/°F.

The 100 ppm/ARO/RTP-MTC should be less negative than -4.0 x 10-4 k/k/°F.

where: BOL stands for Beginning of Cycle Life ARO stands for All Rods Out EOL stands for End of Cycle Life RTP stands for RATED THERMAL POWER 2.4 Shutdown Bank Insertion Limits (Specification 3.1.5) 2.4.1 The shutdown banks shall be withdrawn to a position greater than or equal to 225 steps.

CORE OPERATING LIMITS REPORT, FNP UNIT 1 CYCLE 31 December 2020 Page 4 of 15 2.5 Control Bank Insertion Limits (Specification 3.1.6) 2.5.1 The control rod banks shall be limited in physical insertion as shown in Figure 1.

2.6 Heat Flux Hot Channel Factor - () (Specification 3.2.1) 2.6.1

()

()

for P > 0.5

()

0.5 ()

for P 0.5 where:

=

2.6.2

= 2.50 2.6.3 K(Z) is provided in Figure 2.

2.6.4

()

()

()

for P > 0.5

()

()

0.5()

for P 0.5 2.6.5 Full Power W(Z) values are provided in Table 4.

Part Power (48% RTP) W(Z) values are provided in Table 5.

2.6.6 The () penalty factors are provided in Table 1.

CORE OPERATING LIMITS REPORT, FNP UNIT 1 CYCLE 31 December 2020 Page 5 of 15 2.7 Nuclear Enthalpy Rise Hot Channel Factor -

(Specification 3.2.2) 2.7.1

1 + (1 )

where:

=

2.7.2

= 1.70 2.7.3

= 0.3 2.8 Axial Flux Difference (Specification 3.2.3) 2.8.1 The Axial Flux Difference (AFD) acceptable operation limits are provided in Figure 3.

2.9 Boron Concentration (Specification 3.9.1) 2.9.1 The boron concentration shall be greater than or equal to 2000 ppm.1 2.10 Reactor Core Safety Limits for THERMAL POWER (Specification 2.1.1) 2.10.1 In MODES 1 and 2, the combination of THERMAL POWER, Reactor Coolant System (RCS) highest loop average temperature, and pressurizer pressure shall not exceed the safety limits specified in Figure 4.

2.11 Reactor Trip System Instrumentation Overtemperature T (OTT) and Overpower T (OPT)

Setpoint Parameter Values for Table 3.3.1-1 (Specification 3.3.1) 2.11.1 The Reactor Trip System Instrumentation Overtemperature T (OTT) and Overpower T (OPT) setpoint parameter values for TS Table 3.3.1-1 are listed in COLR Tables 2 and 3.

2.12 RCS DNB Parameters for Pressurizer Pressure, RCS Average Temperature, and RCS Total Flow Rate (Specification 3.4.1) 2.12.1 RCS DNB parameters for pressurizer pressure, RCS average temperature, and RCS total flow rate shall be within the limits specified below:

a. Pressurizer pressure 2209 psig;

b. RCS average temperature 580.3°F; and

c. The minimum RCS total flow rate shall be 273,900 GPM when using the precision heat balance method and 274,800 GPM when using the elbow tap method.

1 This concentration bounds the condition of keff 0.95 (all rods in less the most reactive rod) and subcriticality (all rods out) over the entire cycle. This concentration includes additional boron to address uncertainties and B10 depletion.

CORE OPERATING LIMITS REPORT, FNP UNIT 1 CYCLE 31 December 2020 Page 6 of 15 Table 1 FQ(Z) Penalty Factor Cycle Burnup (MWD/MTU)

FQ(Z) Penalty Factor 0

1.0200 150 1.0200 358 1.0214 566 1.0238 773 1.0256 981 1.0257 1189 1.0240 1397 1.0213 1604 1.0200 2643 1.0200 2851 1.0255 3059 1.0275 3267 1.0276 3474 1.0263 3682 1.0246 3890 1.0229 4098 1.0215 4305 1.0206 4513 1.0200 Notes:

1. The Penalty Factor, to be applied to () in accordance with SR 3.2.1.2, is the maximum factor by which () is expected to increase over a 39 EFPD interval (surveillance interval of 31 EFPD plus the maximum allowable extension not to exceed 25% of the surveillance interval per SR 3.0.2) starting from the burnup at which the () was determined.

2. Linear interpolation is adequate for intermediate cycle burnups.

3. For all cycle burnups outside the range of the table, a penalty factor of 1.0200 shall be used.

CORE OPERATING LIMITS REPORT, FNP UNIT 1 CYCLE 31 December 2020 Page 7 of 15 Table 2 Reactor Trip System Instrumentation - Overtemperature T (OTT)

Setpoint Parameter Values T 577.2°F P = 2235 psig K1 = 1.17 K2 = 0.017/°F K3 = 0.000825/psi 1 30 sec 2 4 sec 4 = 0 sec 5 6 sec 6 6 sec f1(I) =

-2.48 {23 + (qt - qb)}

when (qt - qb) -23% RTP 0% of RTP when -23% RTP < (qt -qb) 15% RTP 2.05 {(qt - qb) - 15}

when (qt - qb) > 15% RTP

CORE OPERATING LIMITS REPORT, FNP UNIT 1 CYCLE 31 December 2020 Page 8 of 15 Table 3 Reactor Trip System Instrumentation - Overpower T (OPT)

Setpoint Parameter Values T 577.2°F K4 = 1.10 K5 = 0.02/°F for increasing Tavg K6 = 0.00109/°F when T > T K5 = 0/°F for decreasing Tavg K6 = 0/°F when T T 3 10 sec 4 = 0 sec 5 6 sec 6 6 sec f2(I) = 0% RTP for all I

CORE OPERATING LIMITS REPORT, FNP UNIT 1 CYCLE 31 December 2020 Page 9 of 15 Table 4 RAOC W(Z)

Axial Point Elevation (feet) 150 MWD/MTU 3000 MWD/MTU 6000 MWD/MTU 10000 MWD/MTU 14000 MWD/MTU 18000 MWD/MTU 1

12.00 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 2

11.80 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 3

11.60 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 4

11.40 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 5

11.20 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 6

11.00 1.1369 1.1560 1.2033 1.2541 1.2052 1.2338 7

10.80 1.1360 1.1532 1.2056 1.2510 1.2026 1.2271 8

10.60 1.1339 1.1488 1.2032 1.2455 1.1976 1.2115 9

10.40 1.1316 1.1437 1.2011 1.2392 1.1917 1.2014 10 10.20 1.1289 1.1438 1.1976 1.2326 1.1914 1.1957 11 10.00 1.1255 1.1423 1.1925 1.2253 1.1906 1.1903 12 9.80 1.1240 1.1438 1.1865 1.2175 1.1887 1.1886 13 9.60 1.1257 1.1436 1.1799 1.2094 1.1940 1.1876 14 9.40 1.1284 1.1413 1.1731 1.2008 1.2022 1.1864 15 9.20 1.1316 1.1375 1.1757 1.1941 1.2075 1.1917 16 9.00 1.1337 1.1327 1.1887 1.1948 1.2221 1.2035 17 8.80 1.1337 1.1252 1.1961 1.1917 1.2345 1.2091 18 8.60 1.1357 1.1219 1.2053 1.1939 1.2440 1.2122 19 8.40 1.1458 1.1302 1.2167 1.2066 1.2556 1.2200 20 8.20 1.1556 1.1389 1.2248 1.2167 1.2714 1.2400 21 8.00 1.1636 1.1459 1.2303 1.2243 1.2833 1.2563 22 7.80 1.1698 1.1513 1.2336 1.2298 1.2925 1.2697 23 7.60 1.1734 1.1545 1.2338 1.2325 1.2985 1.2802 24 7.40 1.1756 1.1566 1.2325 1.2338 1.3027 1.2890 25 7.20 1.1760 1.1569 1.2278 1.2315 1.3021 1.2929 26 7.00 1.1757 1.1565 1.2210 1.2274 1.2991 1.2935 27 6.80 1.1743 1.1552 1.2129 1.2230 1.2951 1.2935 28 6.60 1.1710 1.1524 1.2030 1.2168 1.2887 1.2916 29 6.40 1.1668 1.1487 1.1918 1.2091 1.2800 1.2872 30 6.20 1.1621 1.1444 1.1794 1.1999 1.2689 1.2803 31 6.00 1.1562 1.1391 1.1662 1.1896 1.2561 1.2718 32 5.80 1.1494 1.1331 1.1523 1.1785 1.2419 1.2620 33 5.60 1.1416 1.1273 1.1426 1.1668 1.2257 1.2506 34 5.40 1.1344 1.1358 1.1322 1.1625 1.2072 1.2439 35 5.20 1.1437 1.1451 1.1283 1.1616 1.2058 1.2430 36 5.00 1.1512 1.1538 1.1296 1.1595 1.2028 1.2399 37 4.80 1.1586 1.1618 1.1346 1.1575 1.1987 1.2352 38 4.60 1.1653 1.1693 1.1387 1.1564 1.1929 1.2284 39 4.40 1.1713 1.1761 1.1423 1.1541 1.1857 1.2197 40 4.20 1.1763 1.1819 1.1453 1.1508 1.1773 1.2094 41 4.00 1.1804 1.1866 1.1478 1.1468 1.1677 1.1976 42 3.80 1.1839 1.1920 1.1507 1.1410 1.1558 1.1827 43 3.60 1.1885 1.1985 1.1534 1.1339 1.1426 1.1650 44 3.40 1.1928 1.2035 1.1553 1.1260 1.1341 1.1530 45 3.20 1.1976 1.2105 1.1568 1.1199 1.1267 1.1437 46 3.00 1.2133 1.2212 1.1664 1.1168 1.1243 1.1368 47 2.80 1.2373 1.2319 1.1831 1.1235 1.1328 1.1435 48 2.60 1.2621 1.2487 1.2006 1.1358 1.1462 1.1584 49 2.40 1.2864 1.2747 1.2180 1.1474 1.1592 1.1741 50 2.20 1.3111 1.3028 1.2357 1.1595 1.1724 1.1903 51 2.00 1.3356 1.3303 1.2530 1.1707 1.1842 1.2046 52 1.80 1.3598 1.3575 1.2699 1.1816 1.1956 1.2183 53 1.60 1.3828 1.3834 1.2876 1.1926 1.2073 1.2323 54 1.40 1.4046 1.4078 1.3060 1.2036 1.2191 1.2466 55 1.20 1.4251 1.4307 1.3234 1.2142 1.2307 1.2607 56 1.00 1.4440 1.4514 1.3394 1.2245 1.2422 1.2749 57 0.80 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 58 0.60 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 59 0.40 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 60 0.20 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 61 0.00 1.0000 1.0000 1.0000 1.0000 1.0000 1.0000 Top and bottom 5 axial points excluded per Technical Specification B3.2.1.

CORE OPERATING LIMITS REPORT, FNP UNIT 1 CYCLE 31 December 2020 Page 10 of 15 Table 5 Part Power (48%) RAOC W(Z)

Axial Point Elevation (feet) 150 MWD/MTU 1

12.00 1.0000 2

11.80 1.0000 3

11.60 1.0000 4

11.40 1.0000 5

11.20 1.0000 6

11.00 1.1808 7

10.80 1.1740 8

10.60 1.1610 9

10.40 1.1491 10 10.20 1.1392 11 10.00 1.1210 12 9.80 1.1082 13 9.60 1.1031 14 9.40 1.0925 15 9.20 1.0798 16 9.00 1.0666 17 8.80 1.0628 18 8.60 1.0579 19 8.40 1.0599 20 8.20 1.0602 21 8.00 1.0651 22 7.80 1.0672 23 7.60 1.0670 24 7.40 1.0674 25 7.20 1.0680 26 7.00 1.0692 27 6.80 1.0704 28 6.60 1.0700 29 6.40 1.0694 30 6.20 1.0683 31 6.00 1.0661 32 5.80 1.0634 33 5.60 1.0605 34 5.40 1.0600 35 5.20 1.0747 36 5.00 1.0879 37 4.80 1.1010 38 4.60 1.1136 39 4.40 1.1250 40 4.20 1.1356 41 4.00 1.1454 42 3.80 1.1562 43 3.60 1.1687 44 3.40 1.1803 45 3.20 1.1925 46 3.00 1.2155 47 2.80 1.2471 48 2.60 1.2792 49 2.40 1.3103 50 2.20 1.3399 51 2.00 1.3730 52 1.80 1.4059 53 1.60 1.4370 54 1.40 1.4670 55 1.20 1.4957 56 1.00 1.5229 57 0.80 1.0000 58 0.60 1.0000 59 0.40 1.0000 60 0.20 1.0000 61 0.00 1.0000 Top and bottom 5 axial points excluded per Technical Specification B3.2.1.

CORE OPERATING LIMITS REPORT, FNP UNIT 1 CYCLE 31 December 2020 Page 11 of 15 Figure 1 Rod Bank Insertion Limits versus Rated Thermal Power Fully Withdrawn - 225 to 231 steps, inclusive Fully Withdrawn shall be the condition where control rods are at a position within the interval 225 and 231 steps withdrawn.

Note: The Rod Bank Insertion Limits are based on the control bank withdrawal sequence A, B, C, D and a control bank tip-to-tip distance of 128 steps.

0 25 50 75 100 125 150 175 200 225 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Rod Bank Position (Steps Withdrawn)

Fraction of RATED THERMAL POWER Bank D

(.070, 0)

(1, 187)

Bank C (0, 114)

(.552, 225)

CORE OPERATING LIMITS REPORT, FNP UNIT 1 CYCLE 31 December 2020 Page 12 of 15 Figure 2 K(Z) - Normalized FQ(Z) as a Function of Core Height 0

0.2 0.4 0.6 0.8 1

1.2 0

2 4

6 8

10 12 K(Z) - Normalized Peaking Factor Core Height (feet)

Core Height (ft.)

0.000 6.000 12.000 K(Z) 1.000 1.000 1.000 FQ = 2.50

CORE OPERATING LIMITS REPORT, FNP UNIT 1 CYCLE 31 December 2020 Page 13 of 15 Figure 3 Axial Flux Difference Limits as a Function of Rated Thermal Power for RAOC

(-12, 100)

(-25, 50)

(+9, 100)

(+24, 50) 0 10 20 30 40 50 60 70 80 90 100 110 120

-60

-50

-40

-30

-20

-10 0

10 20 30 40 50 60 Power (% of RATED THERMAL POWER)

Axial Flux Difference (Delta I) %

UNACCEPTABL E OPERATION UNACCEPTABL E OPERATION UNACCEPTABLE OPERATION UNACCEPTABLE OPERATION ACCEPTABLE OPERATION

CORE OPERATING LIMITS REPORT, FNP UNIT 1 CYCLE 31 December 2020 Page 14 of 15 Figure 4 Reactor Core Safety Limits 560 580 600 620 640 660 680 0

0.2 0.4 0.6 0.8 1

1.2 Tavg (degree F)

Power (Fraction of RATED THERMAL POWER) 2425 psig 2235 psig 1985 psig 1831 psig UNACCEPTABLE OPERATION ACCEPTABLE OPERATION

CORE OPERATING LIMITS REPORT, FNP UNIT 1 CYCLE 31 December 2020 Page 15 of 15 Figure 5 Predicted HFP 300 ppm MTC versus Cycle Burnup Cycle Burnup Moderator Temperature (MWD/MTU)

Coefficient (pcm/°F) 15000

-24.67 16000

-24.92 17000

-25.22 18000

-25.48 19000

-25.74

-26.0

-25.5

-25.0

-24.5 15000 16000 17000 18000 19000 Moderator Temperature Coefficient (pcm/°F)

Cycle Burnup (MWD/MTU)