ML031130617

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Core Operating Limits Report
ML031130617
Person / Time
Site: North Anna Dominion icon.png
Issue date: 04/15/2003
From: Funderburk C
Virginia Electric & Power Co (VEPCO)
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
03-291
Download: ML031130617 (21)
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VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 April 15, 2003 United States Nuclear Regulatory Commission Serial No.: 03-291 Attention: Document Control Desk NL&OS/MM Washington, D.C. 20555-0001 Docket No.: 50-338 License No.: NPF-4 VIRGINIA ELECTRIC AND POWER COMPANY NORTH ANNA POWER STATION UNIT I CORE OPERATING LIMITS REPORT Pursuant to North Anna Technical Specification 5.6.5.d, attached is a copy of the Virginia Electric and Power Company's (Dominion) Core Operating Limits Report for North Anna Unit 1 Cycle 17 Pattern EZ, Rev. 1.

No new commitments are intended by this letter. If you have any questions or require additional information, please contact us.

Very truly yours, C. L. Funderburk Director - Nuclear Licensing & Operations Support Attachment cc: U.S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth St. SW, Suite 23 T85 Atlanta, Georgia 30303-8931 Mr. M. J. Morgan NRC Senior Resident Inspector North Anna Power Station 4N0)\

CORE OPERATING LIMITS REPORT North Anna 1 Cycle 17 Pattern EZ RevI -

April 2003 NIC17/EZ COLR Rev I Pagge I of 20

NlC17 CORE OPERATING LIMITS REPORT INTRODUCTION The Core Operating Limits Report (COLR) for North Anna Unit 1 Cycle 17 has been prepared in accordance with North Anna Technical Specification 5.6.5. The technical specifications affected by this report are fisted below:

TS 2.1.1 Reactor Core Safety Limits TS 3.1.1 Shutdown Margin (SDM)

TS 3.1.3 Moderator Temperature Coefficient (MTC)

TS 3.1.5 Shutdown Bank Insertion Limit TS 3.1.6 Control Bank Insertion Limits TS 3.2.1 Heat Flux Hot Channel Factor TS 3.2.2 Nuclear Enthalpy Rise Hot Channel Factor (FNAH)

TS 3.2.3 Axial Flux Difference (AFD)

TS 3.3.1 Reactor Trip System (RTS) Instrumentation TS 3.4.1 RCS Pressure, Temperature, and Flow-DNB Limits TS 3.9.1 Boron Concentration In addition, a technical requirement (TR) in the NAPS Technical Requirements Manual (TRM) refers to the COLR:

TR 3.1.1 Boration Flow Paths - Operating The analytical methods used for determining the core operating limits are those previously approved by the NRC and are discussed in the documents listed in the References Section. Cycle-specific values are presented in bold, while text in italics is provided for information only.

NlCI7/EZ COLR Rev 1 Page 2 of 20

REFERENCES

1. VEP-FRD-42 Rev 1-A, Reload Nuclear Design Methodology, September 1986; Supplement 1, November 1993; Supplement 2, September 1996.

(Methodology for TS 3.1.1 - Shutdown Margin, TS 3.1.3 - Moderator Temperature Coefficient, TS 3.1.5 - Shutdown Bank Insertion Limit, TS 3.1.6 - Control Bank Insertion Limits, TS 3.2.1 -

Heat Flux Hot Channel Factor, TS 3.2.2 - Nuclear Enthalpy Rise Hot Channel Factor and TS 3.9.1 - Boron Concentration)

2. WCAP-9220-P-A RevI, Westinghouse ECCS Evaluation Model - 1981 Version, February 1982.

(Methodology for TS 3.2.1 - Heat Flux Hot Channel Factor)

3. WCAP-9561-P-A Rev 1 Add. 3, BART A-1: A Computer Code for the Best Estimate Analysis of Reflood Transients - Special Report: Thimble Modeling in W ECCS Evaluation Model, July 1986.

(Methodology for TS 3.2.1 - Heat Flux Hot Channel Factor)

4. WCAP-10266-P-A Rev 2, The 1981 Version of the Westinghouse ECCS Evaluation Model Using the BASH Code, March 1987.

(Methodology for TS 3.2.1 - Heat Flux Hot Channel Factor)

5. WCAP-10054-P-A, Westinghouse Small Break ECCS Evaluation Model Using the NOTRUMP Code, August 1985.

(Methodology for TS 3.2.1 - Heat Flux Hot Channel Factor)

6. WCAP-10079-P-A, NOTRUMP, A Nodal Transient Small Break and General Network Code, August 1985.

(Methodology for TS 3.2.1 - Heat Flux Hot Channel Factor)

7. WCAP-12610-P-A, VANTAGE+ Fuel Assembly - Reference Core Report, April 1995.

(Methodology for TS 3.2.1 - Heat Flux Hot Channel Factor)

8. VEP-NE-2-A, Statistical DNBR Evaluation Methodology, June 1987.

(Methodology for TS 3.2.2 - Nuclear Enthalpy Rise Hot Channel Factor and TS 3.4.1 - RCS Pressure, Temperature and Flow DNB Limits)

9. VEP-NE-3-A, Qualification of the WRB-1 CHF Correlation in the Virginia Power COBRA Code, July 1990.

NIC17/EZ COLR Rev 1 Page 3 of 20

T (Methodology for TS 3.2.2 - Nuclear Enthalpy Rise Hot Channel Factor and TS 3.4.1 - RCS Pressure, Temperature and Flow DNB Limits)

10. VEP-NE-1-A, Virginia Power Relaxed Power Distribution Control Methodology and Associated FQ Surveillance Technical Specifications, March 1986; Supplement 1, September 1996.

(Methodology for TS 3.2.1 - Heat Flux Hot Channel Factor and TS 3.2.3 - Axial Flux Difference)

11. WCAP-8745-P-A, Design Bases for the Thermal Overpower AT and Thermal Overtemperature AT Trip Functions, September 1986.

(Methodology for TS 2.1.1 - Reactor Core Safety Limits and TS 3.3.1 - Reactor Trip System Instrumentation)

12. WCAP-14483-A, Generic Methodology for Expanded Core Operating Limits Report, January 1999.

(Methodology for TS 2.1.1 -Reactor Core SafetyLimits, TS 3.1.1 - Shutdown Margin, TS 3.3.1

- Reactor Trip System Instrumentation, TS 3.4.1 - RCS -Pressure, Temperature, and Flow DNB Limits and TS 3.9.1 - Boron Concentration)

NIC17/EZ COLR Rev 1 Page 4 of 20

2.0 SAFETY LIMITS (SLs) 2.1 SLs 2.1.1 Reactor Core SLs 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 limits specified in COLR Figure 2.1-1; and the following SLs shall not be exceeded.

2.1.1.1 The departure from nucleate boiling ratio (DNBR) shall be maintained greater than or equal to the 95/95 DNBR criterion for the DNB correlations and methodologies specified in the References Section.

2.1.1.2 The peak fuel centerline temperature shall be maintained < 4700 'F.

NIC17/EZ COLR Rev 1 Page 5 of 20

COLR Figure 2.1-1 NORTH ANNA REACTOR CORE SAFETY LIMITS 660 -

655 -

650 -

645 -

640 635 630 625 iZ 620 z 615 tM V+/- 610 605 600 595 590 585 580 575 570 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 POWER (fraction of nominal)

NlC17/EZ COLR Rev 1 Page 6 of 20

3.1 REACTIVITY CONTROL SYSTEMS 3.1.1 SHUTDOWN MARGIN (SDM)

LCO 3.1.1 SDMshallbe21.77 % Ak/k.

3.1.3 Moderator Temperature Coefficient (MTC)

LCO 3.1.3 The MTC shall be maintained within the limits specified below. The upper limit of MTC is +0.6 x 104 Ak/k/0 F, when < 70 % RTP, and 0.0 Ak/k/0 F when 2 70 %

RTP.

The BOC/ARO-MTC shall be < +0.6 x 104 Ak/k/ 0 F (upper limit), when <

70 % RTP, and < 0.0 Ak/k/0 F when 2 70 % RTP.

The EOC/AROIRTP-MTC shall be less negative than -5.0 x 104 AkWk/ 0 F (lower limit).

The MTC surveillance limits are:

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

-4.0 x 104A k/k/0 F [Note 2].

The 60 ppm/AROJRTP-MTC should be less negative than or equal to

-4.7 x 10 4 Ak/k/0 F [Note 3].

SR 3.1.3.2 Verify MTC is within -5.0 x 104 Ak/k/ 0 F (lower limit).

Note 2: If the MTC is more negative than _4.0 x 1 0 4 Ak/k/ 0 F, SR 3.1.3.2 shall be repeated once per 14 EFPD during the remainder of the fuel cycle.

Note 3: SR 3.1.3.2 need not be repeated if the MTC measured at the equivalent of equilibrium RTP-ARO boron concentration of < 60 ppm is less negative than -4.7 x 104 Ak/k/OF.

3.1.4 Rod Group Alignment Limits Required Action A. 1.1 Verify SDM to be 2 1.77 % Ak/k.

Required Action B. 1.I Verify SDM to be 2 1.77 % Ak/k.

Required Action D. 1.1 Verify SDM to be > 1.77 % Ak/k.

NlC17/EZ COLR Rev 1 Page 7 of 20

3.1.5 Shutdown Bank Insertion Limits LCO 3.1.5 Each shutdown bank shall be withdrawn to at least 228 steps.

Required Action A.1.1 Verify SDM to be 21.77 % Ak/k.

Required Action B. 1 Verify SDM to be 21.77 % Ak/k.

SR 3.1.5.1 Verify each shutdown bank is withdrawn to at least 228 steps.

3.1.6 Control Bank Insertion Limits LCO 3.1.6 Control banks shall be limited in physical insertion as shown in COLR Figure 3.1-1. Sequence of withdrawal shall be A, B, C and D, in that order; and the overlap limit during withdrawal shall be 100 steps.

Required Action A.1.1 Verify SDM to be 2 1.77 % Ak/k.

Required Action B. 1.1 Verify SDM to be 2 1.77 % Ak/k.

Required Action C.1 Verify SDM to be 2 1.77 % Ak/k.

SR 3.1.6.1 Verify estimated critical control bank position is within the insertion limits specified in COLR Figure 3.1-1.

SR 3.1.6.2 Verify each control bank is within the insertion limits specified in COLR Figure 3.1-1.

SR 3.1.6.3 Verify each control bank not fully withdrawn from the core is within the sequence and overlap limits specified in LCO 3.1.6 above.

3.1.9 PHYSICS TESTS Exceptions - MODE 2 LCO 3.1.9.b SDM is 2 1.77 % Ak/k.

SR 3.1.9.4 Verify SDM to be 2 1.77 % Ak/k.

NIC17/EZ COLR Rev 1 Pa-e 8 of 20

COLR Figure 3.1-1 North Anna 1 Cycle 17 Control Rod Bank Insertion Limits 230 220 t:

210 200 190 180 170 160 O 150 m 140 c)

.6-i u 130 M

o 120 o 110 0L m 100 0

0 90 0

M 80 70 60 50 40 30 20 10 0

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Fraction of Rated Thermal Power NICI7/EZ COLR Rev 1 Page 9 of 20

3.2 POWER DISTRIBUTION LIMITS 3.2.1 Heat Flux Hot Channel Factor (FQ(Z))

LCO 3.2.1 FQ(Z), as approximated by FQM(Z), shall be within the limits specified below.

The change in the FQ(Z) limit for coastdown operation is accommodated by defining a variable quantity, CFQ as indicated below. Then, the following expressions apply to both normal operation and Tavg coastdown regimes.

CFQ = 2.19, for normal operation at full power; CFQ = 2.15, for flux map immediately preceding EOC temperature-coastdown and during subsequent power coastdown operation.

The Measured Heat Flux Hot Channel Factor, FQ"'(Z), shall be limited by the following relationships:

CFQ K(Z)

F for P>0.5 -

P N(Z)

CFQ K(Z)

Q 0.5

<(Z) for P<0.5 0.5 N(z)

THERMAL POWER w e RATED THERMAL POWERa K(Z) is provided in COLR Figure 3.2-1; and N(Z) is a cycle-specific non-equilibrium multiplier on FQ '(Z) to account for power distribution transients during normal operation, provided in COLR Table 3.2-1.

The discussion in the Bases Section B 3.2.1 for this LCO requiresthe application of a cycle dependent non-equilibriummultiplier, N(Z), to the measuredpeakingfactor, FQm(Z), before comparing it to the limit. N(Z) accounts for power distribution transients encountered during normal operation. As finction N(Z) is dependent on the predicted equilibrium FQ(Z) and is sensitive to the axial power distribution, it must be generatedfrom the actual EOC bumup distribution that can only be obtained after the shutdown of the previous cycle. The cycle-specific N(Z) function is presented in COLR Table 3.2-1.

NIC17/EZ COLR Rev I Page 10 of 20

COLR Table 3.2-1 N1C17 N(Z) Table NODE HEIGHT 0 to 1000 1000 to 3000 3000 to 5000 5000 to 7000 7000 to 9000 9000 to 21400 (FEET) MWD/MTU MWD/MTU MWDIMTU MWD/MTU MWD/MTU MWD/MTU 10 10.2 1.144 1.144 1.147 1.147 1.147 1.147 11 10.0 1.142 1.142 1.149 1.149 1.149 1.149 12 9.8 1.139 1.139 1.154 1.154 1.154 1.154 13 9.6 1.138 1.138 1.161 1.161 1.161 1.161 14 9.4 1.139 1.139 1.166 1.166 1.166 1.166 15 9.2 1.143 1.143 1.170 1.170 1.170 1.170 16 9.0 1.144 1.144 1.173 1.173 1.173 1.173 17 8.8 1.147 1.147 1.177 1.177 1.177 1.177 18 8.6 1.152 1.152 1.185 1.185 1.185 1.185 19 8.4 1.158 1.158 1.193 1.193 1.193 1.193 20 8.2 1.162 1.162 1.199 1.199 1.199 1.199 21 8.0 1.164 1.164 1.204 1.204 1.204 1.204 22 7.8 1.166 1.166 1.207 1.207 1.207 1.207 23 7.6 1.165 1.165 1.209 1.209 1.209 1.209 24 7.4 1.163 1.163 1.209 1.209 1.209 1.209 25 7.2 1.160 1.160 1.208 1.208 1.208 1.208 26 7.0 1.155 1.155 1.205 ,1.205 1.205 1.205 27 6.8 1.150 1.150 1.201 1.201 1.201 1.201 28 6.6 1.143 1.143 1.195 1.195 1.195 1.196 29 6.4 1.135 1.135 1.188 1.188 1.188 1.187 30 6.2 1.125 1.125 1.177 1.177 1.177 1.177 31 6.0 1.115 1.115 1.167 1.167 1.167 1.171 32 5.8 1.104 1.104 1.154 1.154 1.154 1.166 33 5.6 1.092 1.092 1.138 1.138 1.138 1.161 34 5.4 1.087 1.087 1.124 1.124 1.124 1.153 35 5.2 1.086 1.086 1.110 1.110 1.110 1.140 36 5.0 1.089 1.089 1.107 1.107 1.107 1.130 37 4.8 1.091 1.091 1.114 1.114 1.114 1.124 38 4.6 1.097 1.097 1.123 1.123 1.123 1.125 39 44 1.105 1.105 1.129 1.129 1.129 1.128 40 4.2 1.114 1.114 1.134 1.134 1.134 1.133 41 4.0 1.123 1.123 1.137 1.137 1.137 1.137 42 3.8 1.131 1.131 1.138 1.140 1.140 1.139 43 3.6 1.140 1.140 1.140 1.141 1.141 1.141 44 3.4 1.148 1.148 1.146 1.140 1.140 1.140 45 3.2 1.156 1.156 1.156 1.141 1.141 1.141 46 3.0 1.166 1.166 1.166 1.146 1.146 1.146 47 2.8 1.177 1.177 1.177 1.156 1.156 1.156 48 2.6 1.187 1.187 1.187 1.165 1.165 1.165 49 2.4 1.197 1.197 1.197 1.176 1.176 1.175 50 2.2 1.206 1.206 1.206 1.185 1.185 1.184 51 2.0 1.215 1.215 1.215 1.193 1.193 1.195 52 1.8 1.223 1.223 1.223 1.201 1.201 1.207 These decks were generated for normal operation flux maps which are typically taken at full power.

Consistent with the RPDC topical methodology, additional N(z) decks may be generated if necessary.

NIC17/EZ COLR Rev I Page 11 of 20

COLR Figure 3.2-1 K(Z) - Normalized FQ as a Function of Core Height 1.2 1.1 1.0 0.9 0.8 LR 0.7 a

wu N

< 0.6 0

z A 0.5 N

0.4 0.3 0.2 0.1 0.0 0 1 2 3 4 5 6 7 - 8 9 10 11 12 13 CORE HEIGHT (FT)

NICI7/EZ COLR Rev 1 Page 12 of 20

3.2.2 Nuclear Enthalpy Rise Hot Channel Factor (FINM)

LCO 3.2.2 FNAH shall be within the limits specified below.

FI < 1.49{1 + 0.3(1 - P))

THERMAL POWER where: P= RATED THERMAL POWER SR 3.2.2.1 Verify FNAH is within limits specified above.

3.2.3 AXIAL FLUX DIFFERENCE (AFD)

LCO 3.2.3 The AFD in % flux difference units shall be maintained within the limits specified in COLR Figure 3.2-2.

NIC17JEZ COLR Rev I Page 13 of 20

COLR Figure 3.2-2 N1C17 Axial Flux Difference Limits 0 MWD/MTU to EOC 120 110 100 90 80 0

0 70 E

a)

I--

60 L-

  • 0 C) 0 50 C)

EL 40 30 20 10 0 4-

-30 -20 -10 0 10 20 30 Percent Flux Difference (Delta-l)

NIC17/EZ COLR Rev I Page 14 of 20

3.3 INSTRUMENTATION 3.3.1 Reactor Trip System (RTS) Instrumentation TS Table 3.3.1-1 Note 1: Overtemperature AT The Overtemperature AT Function Allowable Value shall not exceed the following nominal trip setpoint by more than 2% of AT span, with the numerical values of the parameters as specified below.

AT < ATO{KI-K 2 (1 +2S)) [T-T']+K3 (P-P')-f (Al)}

where: AT is measured RCS AT, 'F.

ATo is the indicated AT at RTP, OF.

s is the Laplace transform operator, sec- 1.

T is the measured RCS average temperature, 'F.

T' is the nominal Tavg at RTP, < 586.8 'F.

P is the measured pressurizer pressure, psig.

P' is the nominal RCS operating pressure, 2 2235 psig.

K, < 1.2715 K2 Ž 0.02172 /`F K3 0.001144 /psig Th, 2= time constants utilized in the lead-lag controllerfor Tavg rl 2 23.75 sec To < 4.4 sec (1 +TIs)/(1 + r2s) = function generated by the lead-lag controllerforTavS dynamic compensation f1(AI) 2 0.0165{ (q, - qb)} when (q, - qb) < -44% RTP 0 when -44% RTP < (q, - qb) < +3% RTP 0.0198{(q, - qb) - 3} when (q, - qb) > +3% RTP

[See footnote]#

Where q, and qb are percent RTP in the upper and lower halves of the core, respectively, and q, + qb is the total THERMAL POWER in percent RTP.

Footnote: The units for f,(AI) = 0 in the North Anna TS and NUREG-143 1 are incorrectly specified as "% of RTP." f1(AI) being dimensionless should have no units. This discrepancy is being addressed by the North Anna Corrective Action System.

NlC17/EZ COLR Rev 1 PagYe 15 of 20

TS Table 3.3.1-1 Note 2: Overpower AT The Overpower AT Function Allowable Value shall not exceed the following nominal trip setpoint by more than 2% of AT span, with the numerical values of the parameters as specified below.

AT<ATo {K 4 -K5 [1+5 ]T-K 6 [T-T']-f 2 (AI)}

where: AT is measured RCS AT, OF.

ATo is the indicated AT at RTP, OF.

s is the Laplace transform operator, sec 1.

T is the measured RCS average temperature, 'F.

T' is the nominal Tavg at RTP, < 586.8 OF.

K4 < 1.0865 K5 2 0.0197 /'F for increasing Tavg K6 2 0.00162 /'F when T > T' 0 /'F for decreasing Tavg 0 /'F when T < T' T3= time constant Utilized in the rate lag controllerforTavg 132 9.5 sec r3sl(l +-3s) = function generated by the rate lag controllerforTag dynamic compensation f2 (AI) = 0, for all Al.

NIC17/EZ COLR Rev 1 Page 16 of 20

3.4 REACTOR COOLANT SYSTEM (RCS) 3.4.1 RCS Pressure, Temperature, and Flow Departure from Nucleate Boiling (DNB) Limits LCO 3.4.1 RCS DNB parameters for pressurizer pressure, RCS average temperature, and RCS total flow rate shall be within the limits specified below:

a. Pressurizer pressure is greater than or equal to 2205 psig;
b. RCS average temperature is less than or equal to 591 'F; and
c. RCS total flow rate is greater than or equal to 295,000 gpm.

SR 3.4.1.1 Verify pressurizer pressure is greater than or equal to 2205 psig.

SR 3.4.1.2 Verify RCS average temperature is less than or equal to 591 'F.

SR 3.4.1.3 Verify RCS total flow rate is greater than or equal to 295,000 gpm.

SR 3.4.1.4 ------------------------------ NOTE--------------------------------------------

Not required to be performed until 30 days after 2 90% RTP.

Verify by precision heat balance that RCS total flow rate is 2 295,000 gpm.

N1C17/EZ COLR Rev 1 Page 17 of 20

3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS) 3.5.6 Boron Injection Tank (BIT)

Required Action B.2 Borate to an SDM 2 1.77 % Ak/k at 200 'F.

NIC17/EZ COLR Rev 1 Page 18 of 20

3.9 REFUELING OPERATIONS 3.9.1 Boron Concentration LCO 3.9.1 Boron concentrations of the Reactor Coolant System (RCS), the refueling canal, and the refueling cavity shall be maintained > 2600 ppm.

Note: The refueling boron concentrationsatisfies the more restrictive of the following conditions: (a) keff O.95 , or (b) boron concentration Ž2600 ppm.

SR 3.9.1.1 Verify boron concentration is within the limit specified above.

NlC17/EZ COLR Rev 1 Page 19 of 20

NAPS TECHNICAL REQUIREMENTS MANUAL TRM 3.1 REACTIVITY CONTROL SYSTEMS TR 3.1.1 Boration Flow Paths - Operating Required Action E.2 Borate to a SHUTDOWN MARGIN > 1.77 % Ak/k at 200 IF, after xenon decay.

NlC17/EZ COLR Rev 1 Page 20 of 20

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