BVY 05-102, Core Operating Limits Report for Cycle 25

Core Operating Limits Report for Cycle 25

ML053260432
Person / Time
Site:	Vermont Yankee
Issue date:	11/15/2005
From:	Devincentis J Entergy Nuclear Northeast, Entergy Nuclear Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
BVY 05-102
Download: ML053260432 (27)

Text

Entergy Nuclear Northeast Entergy Nuclear Operations, Inc.

I '~Entergy I - i Vermont Yankee RO. Box 0500 185 Old Ferry Road Brattleboro, Vr 05302-0500 Tel 802 257 5271 November 15, 2005 BVY 05-102 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555

Subject:

Vermont Yankee Nuclear Power Station License No. DPR-28 (Docket No. 50-271)

Core Operating Limits Report for Cycle 25 In accordance with Section 6.6.C of the Vermont Yankee Technical Specifications, enclosed is the Core Operating Limits Report (COLR) for Cycle 25. This report presents the cycle-specific operating limits for Cycle 25 of the Vermont Yankee Nuclear Power Station.

If you have any questions concerning this transmittal, please contact me at (802) 258-4236.

Sincerely, d~Xnes M. DeVincentis

&'Manager,Licensing Enclosure cc: USNRC Region 1 Administrator USNRC Resident Inspector - VYNPS USNRC Project Manager - VYNPS Vermont Department of Public Service pz)CD

I Vermont Yankee Nuclear Power Station Cycle 25 Core Operating Limits Report Revision 0 October 2005 Prepared \I \1#o IoIZL-c)5 Reactor Engineer (Print/Sign) Date Reviewed Vri z.t.eZE{

Reactor EngitVer (Print/Sign) Date Approved A PI) i/i o<

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SuPerirt nd ctor Engineering (Print/Sign) Date Reviewed V 61mW

)c-rv'i LUi 1%Atf I io-) If1 1Date Plant Operations R vi w Committee (Print/Sign)

Approved AJA Io General Manager, Plant Opera*Pns rint/Sign) Date

REVISION RECORD Revision Date Description 25 0 10/2005 Cycle 25 revision.

Cycle 25 COLR Vermont Yankee Nuclear Power Station Revision 0 Revision Record Page iofi

ABSTRACT This report presents Cycle 25 specific operating limits at current license thermal power (1593 thermal megawatts)for the operation of the Vermont Yankee Nuclear Power Station as specified in Technical Specification 6.6.C. The limits included in the report are average planar linear heat generation rate, linear heat generation rate, minimum critical power ratio, and thermal-hydraulic stability exclusion region.

The requirement of Technical Specifications Table 3.2.5 pertaining to the rod block monitor (RBM) setpoint equation maximum value of N for single loop and dual loop operation are included in this report.

Cycle 25 COLR Vermont Yankee Nuclear Power Station Revision 0 Abstract Page iofi

TABLE OF CONTENTS Paze LIST OF TABLES ............ ii LIST OF FIGURES .............. iii

1.0 INTRODUCTION

2.0 CORE OPERATING LIMITS .. 2 2.1 Average Planar Linear Heat Generation Rate Limits (APLHGR) .2 2.2 Minimum Critical Power Ratio (MCPR) Limits .2 2.3 Linear Heat Generation Rate (LHGR) Limits .4 2.4 Thermal-Hydraulic Stability Exclusion Region .5 2.5 Power/Flow Map .7 2.6 Single Loop Operation .7 2.7 Rod Block Monitoring ............... .... 8 REFERENCES .. ......... 20 Cycle 25 COLR Vermont Yankee Nuclear Power Station Revision 0 Table of Contents Page i of iii

TABLE OF CONTENTS (Continued)

LIST OF TABLES Number Title Page Table 2.1-1 MAPLHGR Limits for GE 14-P I ODNAB426-16G6.0-l OOT- I 50-T6-2682 Fuel Bundle No. 2682 ..................................... 9 Table 2.1-2 MAPLHGR Limits for GE14-PI ODNAB390-14GZ-1 0OT-150-T6-2683 Fuel Bundle No. 2683 ..................................... 9 Table 2.1-3 MAPLHGR Limits for GE14-PI ODNAB388-17GZ-1 COT-150-T6-2684 Fuel Bundle No. 2684 .................................... 10 Table 2.1-4 MAPLHGR Limits for GE14-PI ODNAB422-16GZ-1 COT-150-T6-2862 Fuel Bundle No. 2862 .................................... 10 Table 2.1-5 MAPLHGR Limits for GE14-PI ODNAB383-13G6.0-IOOT-1 50-T6-2863 Fuel Bundle No. 2863 ..................................... 11 Table 2.1-6 MAPLHGR Limits for GE14-PI ODNAB388-17GZ-1 COT-150-T6-2864 Fuel Bundle No. 2864 ..................................... 11 Table 2.1-7 MAPLHGR Limits for GE14-PI ODNAB383-17G6.0-1 OOT-1 50-T6-2865 Fuel Bundle No. 2865 .............  ; 12 Table 2.1-8 MAPLHGR Limits for GEI 4-P I ODNAB394-7G5.0/6G4.0-1 OOT-1 50-T6-2566 Fuel Bundle No. 2566 ............. 12 Table 2.1-9 MAPLHGR Limits for GE14-PI ODNAB394-8G5.0/6G4.0-1 OOT-150-T6-2595 Fuel Bundle No. 2595 ....... 13 Table 2.1-10 MAPLHGR Limits for GE14-P IODNAB394-12G5.0-l COT-1 50-T6-2596 Fuel Bundle No.2596 ............. 13 Table 2.2-1 Cycle 25 Rated MCPR Operating Limits (OLMCPR) .............................. 14 Table 2.2-2 RBM Setpoint .................................... 14 Cycle 25 COLR Vermont Yankee Nuclear Power Station Revision C Table of Contents Page ii of iii

TABLE OF CONTENTS (Continued)

LIST OF FIGURES Number Title Page 2.2-1 Power Dependent K (P) / MCPR (P) Limits .................................... 15 2.2-2 Flow Dependent MCPR Operating Limit MCPR (F) ................................... 16 2.3-1 Power Dependent LHGRFAC (P) Multiplier .................................... 17 2.3-2 LHGR Flow Factor LHGRFAC (F) ................................... 18 2.4-1 Limits of Power/Flow Operation ................................... 19 Cycle 25 COLR Vermont Yankee Nuclear Power Station Revision 0 Table of Contents Page iii of iii

1.0 INTRODUCTION

This report provides the cycle-specific limits for operation of the Vermont Yankee Nuclear Power Station in Cycle 25. It includes the limits for the average planar linear heat generation rate, linear heat generation rate, minimum critical power ratio, and thermal-hydraulic stability exclusion region. If any of these limits are exceeded, action will be taken as defined in the Technical Specifications.

As specified in Technical Specifications Table 3.2.5, the rod block monitor (RBM) setpoint equation maximum value of N for single loop and dual loop operation are included in this report.

This Core Operating Limits report for Cycle 25 has been prepared in accordance with the requirements of Technical Specifications 6.6.C. The core operating limits have been developed using the NRC-approved methodologies listed in References 3.1 through 3.4. The methodologies are also listed in Technical Specification 6.6.C. The bases for these limits are in References 3.5 through 3.8.

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2.0 CORE OPERATING LIMITS The Cycle 25 operating limits have been defined using NRC-approved methodologies. Cycle 25 must be operated within the bounds of these limits and all others specified in the Technical Specifications.

2.1. Average Planar Linear Heat Generation Rate Limits (APLHGR) (T.S. 3.11 .A)

APLHGR is applicable to a specific planar height and is equal to the sum of the linear heat generation rate (LHGR) for all of the fuel rods in the specific bundle at the specific height divided by the number of fuel rods in the fuel bundle at the height.

The maximum APLHGR (MAPLHGR) limit is a function of reactor power, core flow, fuel type, and average planar exposure. The cycle dependent limits are developed using NRC approved methodology described in References 3.1 and 3.3. The MAPLHGR limit ensures that the peak clad temperature during a LOCA will not exceed the limits as specified in 10CFR50.46 (b) (1) and that the fuel design analysis criteria defined in References 3.1 and 3.3 will be met.

Tables 2.1-1 through 2.1-10 provide a limiting composite of MAPLHGR values for each fuel type, which envelope the lattice MAPLHGR values employed by the process computer (Reference 3.6). When hand calculations are required, these MAPLHGR values are used for all lattices in the bundle.

For single recirculation loop operation, the limiting values shall be the values from these Tables listed under the heading "Single Loop Operation." These values are obtained by multiplying the values for two loop operation by 0.82 (Reference 3.6).

The power and flow dependent MAPLHGR limits (MAPFAC multipliers) are identical to the LHGR limits (LHGRFAC multipliers) in Figure 2.3-1 and 2.3-2 since the power and flow dependent LHGRFAC multiplier are sufficient to provide adequate protection for the off-rated conditions from an ECCS-LOCA. Therefore, a specific power and flow dependent MAPLHGR limit (MAPFAC multipler) is not required.

2.2. Minimum Critical Power Ratio (MCPR) Limits (T.S. 3.1 1.C)

MCPR is the smallest Critical Power Ratio (CPR) that exists in the core for each iype of fuel and shall be equal to, or greater than the Operating Limit MCPR (OLMCPR), which is a function of Core Thermal Power, Core Flow, Fuel Type, and Scram Time (Tau).

The rated Operating Limit MCPR at steady-state rated power and increased core flow operating conditions is derived from the cycle specific fuel cladding integrity Safety Limit MCPR and the delta CPR, as determined from the most limiting transient event.

The rated OLMCPR will ensure that the Safety Limit MCPR is not exceeded during any abnormal operational occurrence (AOO) (Reference 3.6).

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The rated OLMCPR for two loop and single loop operation is documented in Table 2.2-1 and is dependent on scram time (Tau) surveillance data at position 36 (Reference 3.5).

Determination of Tau:

i. First, TAne shall be determined:

ENjT, where:

n = number of scram time tests thus far this cycle, N, = number of active rods measured in surveillance i, and

-e= average scram time to position 36 dropout of all rods measured in surveillance i.

ii. Second, TB shall be determined:

r 8 =,+1.65 FN, EI N,I where:

, = 0.830 = mean of the distribution for average scram insertion time to position 36 dropout used in the ODYN Option B analysis.

a= 0.019 = standard deviation of the distribution for average scram insertion time to position 36 dropout used in the ODYN Option B analysis.

N1 = number of active rods measured during the first surveillance test at BOC.

iii. Third, determine the OLMCPR, as follows:

If TrV < TB, then OLMCPROpiOmB from Table 2.2.1 may be used.

If TaVe> TB, then a new OLMCPR shall be calculated:

OLMCPRNew = OLMCPROprionB + >ave - TB (OLMCPR ption - OLMCPR on )

TrA - TB OtLn Cycle 25 COLR Vernont Yankee Nuclear Power Station Revision 0 Page 3 of 20

where:

OLMCPRoptianA= Option A OLMCPR from Table 2.2.1 based on Option A analysis using full core scram times listed in Technical Specification 3.3.C.1.2.

OLMCPRoptionB= Option B OLMCPR from Table 2.2.1 based on Option B analysis described in Reference 3.1.

r4 = 1.096 seconds = Technical Specification 3.3.C.1.2 core average scram time to drop-out of position 36.

The OLMCPR is the greater of the flow and power dependent MCPR operating limits, MCPR (F) and MCPR (P).

OLMCPR = AMX (MCPR (P), MCPR (F))

The flow dependent MCPR operating limits, MCPR (F) is provided in Figure 2.2-2.

For core thermal powers less than 30%, the power dependent MCPR operating limit, MCPR (P), is provided in Figure 2.2-1. For core thermal powers equal to or greater than 30%, MCPR (P) is the product of the rated OLMCPR presented in Table 2.2-1 and the K (P) factor presented in Figure 2.2-1.

Cycle exposure dependent limits are provided through the end of rated exposure point, which is expected to be the maximum exposure attainable at full power during ICF operation. Coastdown operation is allowable down to 40% rated CTP.

For single recirculation loop operation, the MCPR limits at rated flow shall be the values from Table 2.2-1 listed under the heading, "Single Loop Operation." The single loop values are obtained by adding 0.02 to the two loop operation values (TS 1.1.A.1).

2.3. Linear Heat Generation Rate (LHGR) Limits (T.S. 3.11 .B)

LHGR is the heat generation rate per unit length of fuel rod. It is the integral of the heat flux over the heat transfer area associated with the unit length. By maintaining the operating LHGR below the applicable LHGR limit, it is assured that all thermal-mechanical design basis and licensing limits for the fuel will be satisfied.

The maximum LHGR limit is a function of reactor power, core flow, fuel and rod type, and fuel rod nodal exposure. The limit is developed using NRC approved methodology described in Reference 3.1 to ensure the cladding will not exceed its yield stress and that the fuel thermal-mechanical design criteria will not be violated during any postulated transient events.

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During reactor power operation, the LHGR of any rod in any fuel bundle at any axial location shall not exceed the rated power and rated core flow limits (LHGRtd) for each fuel and rod type as a function of fuel rod nodal exposure listed in Reference 3.7.

The LHGR limits for the fuel pin axial locations with no gadolinium and maximum gadolinium concentration listed in Reference 3.7 are expected to operate near the LHGR limits.

There are also fuel pins with axial locations that have gadolinium concentrations that are less than the maximum concentration anywhere in the bundle. The LHGR limits for these axial locations range uniformly between the case of no gadolinium and the most limiting gadolinium concentration.

For other than rated power and flow conditions (below 25% core thermal power thermal limit calculation is not required), the applicable limiting LHGR values for each fuel type is the smaller of the power and flow dependent LHGR limits multiplied by the applicable power and flow adjustment factor or the LHGR limit multiplied by 0.82 when in single loop operation.

LHGR limit = MIN (LHGR (P), LHGR (F)).

Power-dependent LHGR limit, LHGR (P), is the product of the LHGR power dependent LHGR limit adjustment factor, LHGRFAC (P), shown in Figure 2.3-1 and the LHGRstd.

LHGR (P) = LHGRFAC (P) x LHGRstd The flow-dependent LHGR limit, LHGR (F), is the product of the LHGR flow dependent LHGR limit adjustment factor, LHGRFAC (F), shown in Figure 2.3-2 and the LHGRsd.

LHGR (F) = LHGRFAC (F) x LHGRstd 2.4. Thermal-Hydraulic Stability Exclusion Region (T.S. 3.6.J)

For Cycle 25, based on decay ratios at the most limiting point on the power/flow, the predominate oscillation mode is core-wide. Normal plant operation is not allowed inside the bounds of the exclusion region defined in Figure 2.4-1. These power and flow limits are applicable for Cycle 25. Operation inside of the exclusion region may result in a thermal-hydraulic oscillation. Intentional operation within the buffer region is not allowed unless the Stability Monitor is operable. Otherwise, the buffer region is considered part of the exclusion region (Reference 3.6).

The coordinates of the Exclusion Region are as follows:

Point Power (%) l Flow (%)

A 82.32 55.28 B 38.81 31.22 Cycle 25 COLR Vermont Yankee Nuclear Power Station Revision 0 Page 5 of 20

The equation for the boundary is as follows:

I TY - JVB PB where, P = a core thermal power value on the Exclusion Region boundary (% of rated),

W the core flow rate corresponding to power, P, on the Exclusion Region boundary (% of rated),

PA = core thermal power at State Point A (% of rated),

PB = core thermal power at State Point B (% of rated),

WA = core flow rate at State Point A (% of rated),

WB = core flow rate at State Point B (% of rated),

The range of validity-of the fit is: 31.22% <0/oFlow <55.28%

The coordinates of the Buffer Region are as follows:

Point Power (%) l Flow (%)

C 86.91 - 60.28

[ D 33.81 30.88 The generic equation used to generate the 5% buffer zone exclusion region boundary is:

where, P = a core thermal power value on the Buffer Zone boundary (% of rated),

W = the core flow rate corresponding to power, P, on the 5% Buffer Zone boundary (% of rated),

Pc = core thermal power at State Point C (% of rated),

PD = core thermal power at State Point D (% of rated),

Wc = core flow rate at State Point C (% of rated),

WD = core flow rate at State Point D (% of rated),

The range of validity of the fit is: 30.88% < 0/oFlow <60.28%.

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2.5. Powver/Flow Map Power operation, with respect to Core Thermal Power/Total Core Flow combinations, is allowed within the outlined area of Figure 2.4-1. This area is bounded by the following lines:

Minimum Pump Speed Line; This line approximates operation at minimum pump speed. Plant start-up is performed with the recirculation pumps operating at approximately 20% speed. Reactor power level will approximately follow this line during the normal control rod withdrawal sequence.

Minimum Power Line; This lines approximates the interlock that requires recirc pump speed to be at a minimum in terms of feedwater flow. This interlock ensures NPSH requirements jet pumps and recirculation pumps are met.

Natural Circulation Line; The operating state the reactor follows along this line for the normal control rod withdrawal sequence in the absence of recirculation pump operation.

Exclusion Region - The exclusion region is a power/flow region where an instability can occur. The boundary for the exclusion region is established through use of an analysis procedure which is demonstrated to be conservative relative to expected operating conditions.

. 5% Buffer Region Boundary; The Buffer Region is determined by adjusting the endpoints of the Exclusion Region and increasing the flow on the highest rod line by 5% and decreasing power on the natural circulation line by 5%.

Rated Power Line and MELLLA Boundary; These lines provide the upper power limit and operating domain assumed in transient analyses.

ICF Boundary; This line represents the highest allowable analyzed core flow. The analysis in Reference 3.4 supports the maximum attainable core flow being 107%

of rated core flow.

108% rod line; this line represents the ELLLA operating boundary and is the maximum load line allowed in single loop operation.

2.6. Single Loop Operation SLO was not analyzed for operation in the MELLLA region. The power/flow operating condition for Single Loop Operation (SLO) is core power less than 1239 MWVTh (77.77%CTP), core flow less than 26.35 Mg/hr (54.9%) and maximum rod line less than 108%. (References 3.2 and 3.9)

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2.7. Rod Block Monitoring The Rod Block Monitor (RBM) control rod block functions are no longer credited in the Rod Withdrawal Error (RWE) Analysis and, as such, do not affect the MCPR Operating Limit. The RBM setpoints are based on providing operating flexibility in the MELLLA region (T.S. Bases 3.2). The rod block monitor (RBM) setpoint equation maximum value of N for single loop and dual loop operation are listed in Table 2.2-2.

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Table 2.1-1 MAPLHGR Limits for GE14-PIODNAB426-16G6.0-IOOT-150-T6-2682 Fuel Bundle No. 2682 MAPLHGR (kWV/ft)

Average Planar Exposure (GWd/ST) Two Loop Operation Single Loop Operation 0.00 12.82 10.51 19.12 12.82 10.51 57.61 8.00 6.56 63.50 5.00 4.10 Technical Specification

References:

3.6.G.la and 3.1 l.A.

1 MAPLHGR for single loop operation is obtained by multiplying MAPLHGR for two loop operation by 0.82.

Table 2.1-2 MAPLHGR Limits for GE14-PIODNAB390-14GZ-1 OOT-1 50-T6-2683 Fuel Bundle No. 2683 MAPLHGR (k-W/ft)

Average Planar Exposure (GWd/ST) Two Loop Operation Single Loop Operation' 0.00 12.82 10.51 19.12 12.82 10.51 57.61 8.00 6.56 63.50 5.00 4.10 Technical Specification

References:

3.6.G.la and 3.1 l.A.

'MAPLHGR for single loop operation is obtained by multiplying MAPLHGR for two loop operation by 0.82.

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Table 2.1-3 MAPLHGR Limits for GE14-P1ODNAB388-17GZ-IOOT-150-T6-2684 Fuel Bundle No. 2684 MAPLHGR (kWY/ft)

Average Planar Exposure (GWd/ST) Two Loop Operation Single Loop Operation 0.00 12.82 10.51 19.12 12.82 10.51 57.61 8.00 6.56 63.50 5.00 4.10 Technical Specification

References:

3.6.G.la and 3.11 A.

l MAPLHGR for single loop operation is obtained by multiplying MAPLHGR for two loop operation by 0.82.

Table 2.1-4 MAPLHGR Limits for GE14-PI ODNAB422-16GZ-1 OOT- 150-T6-2862 Fuel Bundle No. 2862 MAPLHGR (kWV/ft)

Average Planar Exposure (GWd/ST) Two Loop Operation Single Loop Operation' 0.00 12.82 10.51 19.12 12.82 10.51 57.61 8.00 6.56 63.50 5.00 4.10 Technical Specification

References:

3.6.G.Ia and 3.1 I.A.

'MAPLHGR for single loop operation is obtained by multiplying MAPLHGR for two loop operation by 0.82.

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Table 2.1-5 MAPLHGR Limits for GE14-PI ODNA383-1 3G6.0-1 OOT-l 50-T6-2863 Fuel Bundle No. 2863 MAPLHGR (kW/ft)

Average Planar Exposure (GWcd/ST) Two Loop Operation Single Loop Operation' 0.00 12.82 10.51 19.12 12.82 10.51 57.61 8.00 6.56 63.50 5.00 4.10 Technical Specification

References:

3.6.G.Ia and 3.1 I.A.

1MAPLHGR for single loop operation is obtained by multiplying MAPLHGR for two loop operation by 0.82.

Table 2.1-6 MAPLHGR Limits for GEl4-PI ODNAB388-17GZ-10OT-1 50-T6-2864

• Fuel Bundle No. 2864 MAPLHGR (kW/ft)

Average Planar Exposure (GWdIST) Two Loop Operation Single Loop Operation 0.00 12.82 10.51 19.12 12.82 10.51 57.61 8.00 6.56 63.50 5.00 4.10 Technical Specification

References:

3.6.G.la and 3.1l.A.

XMAPLHGR for single loop operation is obtained by multiplying MAPLHGR for two loop operation by 0.82.

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Table 2.1-7 MAPLHGR Limits for GE14-PI ODNAB383-17G6.0-1 OOT-1 50-T6-2865 Fuel Bundle No. 2865 MAPLHGR (kW/ft)

Average Planar Exposure (GWd/ST) Two Loop Operation Single Loop Operation' 0.00 12.82 10.51 19.12 12.82 10.51 57.61 8.00 6.56 63.50 5.00 4.10 Technical Specification

References:

3.6.G.la and 3.1 l.A.

XMAPLHGR for single loop operation is obtained by multiplying MAPLHGR for two loop operation by 0.82.

Table 2.1-8 MAPLHGR Limits for GE14-PI ODNAB394-7G5.0/6G4.0-1OOT-150-T6-2566 Fuel Bundle No. 2566 MAPLHGR (kW/ft)

Average Planar Exposure (GWd/ST) Two Loop Operation Single Loop Operation' 0.00 12.82 10.51 19.12 12.82 10.51 57.61 8.00 6.56 63.50 5.00 4.10 Technical Specification

References:

3.6.G.la and 3.1 l.A.

'MAPLHGR for single loop operation is obtained by multiplying MAPLHGR for two loop operation by 0.82.

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Table 2.1-9 MAPLHGR Limits for GE14-P 1ODNAB394-8G5.0/6G4.0- lOOT-1 50-T6-2595 Fuel Bundle No. 2595 MAPLHGR (kWlft)

Average Planar Exposure (GWd/ST) Two Loop Operation Single Loop Operation' 0.00 12.82 10.51 19.12 12.82 10.51 57.61 8.00 6.56 63.50 5.00 4.10 Technical Specification

References:

3.6.G.la and 3.1 l.A.

l MAPLHGR for single loop operation is obtained by multiplying MAPLHGR for two loop operation by 0.82.

Table 2.1-10 MAPLHGR Limits for GE14-PIODNAB394-12G5.0-OOT-150-T6-2596 Fuel Bundle No. 2596 MAPLHGR (kW/ft)

Average Planar Exposure (GWd/ST) Two Loop Operation Single Loop Operation 0.00 12.82 10.51 19.12 12.82 10.51 57.61 8.00 6.56 63.50 5.00 4.10 Technical Specification

References:

3.6.G.la and 3.11.A.

lMAPLHGR for single loop operation is obtained by multiplying MAPLHGR for two loop operation by 0.82.

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Table 2.2-1 Cvcle 25 Rated MCPR Operating Limits (OLMCPR)

Cycle Exposure Two Loop Single Loop Option Range Operation 2 Operation Option A 0 to 12611 MWd/St 1.49 1.51 Beyond 12611 MWd/St 1.59 1.61 Option B 0 to 12611 MWd/St 1.40 1.42 Beyond 12611 MWd/St 1.42 1.44 Source: References 3.6.

I The MCPR operating limit is increased by 0.02 for single loop operation.

2 The two loop MCPR operating limits bound ICF operation throughout the cycle.

Table 2.2-2 RBM Setpoint 3 Dual Loop Operation Maximum Value of "N" in RBM Setpoint Equation - 62.

Single Loop Operation Maximum Value of "N" in RBM Setpoint Equation - 68.

Source: Reference 3.8 Technical Specification

References:

Table 3.2.5.

3 The Rod Block Monitor (RBM) trip setpoints are determined by the equation shown in Table 3.2.5 of the Technical Specifications.

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Power Dependent K (P) / MCPR (P) Limits 2.60

- I

> 60% Flow

/-1 II 1 I1 I 2.40 Operating limit MCPR (P) - K(P) x Operating Limit MCPR (100)

For P < 25%: No Thermal Limits Required 2.20 60% Flow For 25% s P < 300%, > 60% Flow:

OLMCPR (P) - 2.48- 0.034 x (P - 25%)

2.00 I I For 25% S P < 30%, S 60% Flow:

r- OLMCPR (P) = 2.07 - 0.026 x (P - 25%)

1 For 30% S P < 45%: K (P) 1.55 - 0.0135 x (P - 25%)

E1.80 c-r- _ _- ___I For 45%5SP < 100%: K (P) = 1.28 - 0.00509 x (P - 45%)

1.60 ForP> 100%: K(P) 1.00 I

1.40 -

1.20 1.00 25 30

__T_

35 40 45 50 55 60 65 70 I

75 I--

80 85 90 95 100 Power (% Rated)

Figure 2.2-1 Power Dependent.K (P) / MCPR (P) Limits (Technical Specification Reference 3.11 .C)

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Flow Dependend MCPR Operating Limit MCPR(F) l.80 1.70 + 4 4 4 4 4 +/- I For W (C) (% Rated Core Flow) > 30%0 C-U MCPR (F) = MAX (1.20,A (F) ' (%(C) / 100) + B(F))

1.60 4 4 4 tI Max Run Flow S 109.5%

ta .4 I I -I I A (F) = - 0.602 B (F) = 1.747 .

U r- Maximum Flow Rate 109.5%

U 1.40 C4

)_ I I -N U 14 0

U' I J E_ ______ _ - -I in 32

.20 - ~

InA I .su 20 30 40 50 60 70 80 90 100 110 120 Core Flow (% Rated)

Figure 2.2-2 Flow Dependent MCPR Operating Limit MCPR (F)

(Technical Specification Reference 3.1 1.C)

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Power Dependant LI-IGRFAC(P) Multiplier 1.10 1.00 0.90 0.80 S60% Flow rU 0.70 LHGR (P) = LHGRFAC (P) x LHGRstd C:- Where LHGRstd = Rated LHGR limits 0

= 0.60 . l _ ___ - For P<25%: No Thermal Urnits Required For 25% S P < 30%, > 60% FlowA

_ 60%_Flowl_

__ LHGRFAC (P) = 0.586.+0.0084 x (P-25%)

0.50 > 60% Flow For 25% S P< 30%, 5 60% Flow.

LHGRFAC (P) = 1.0 + 0.00523 x (P-1 00%)

0.40 For 30°h S P < 100%

LHGRFAC (P) = 1.0 4 0.00523 x (P-1 00%)

0.30 For P 100%: LHGRFAC (P) = 1.0 T_ T I 0.20 _ . i , -- - -

25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 Power (% Rated)

Figure 2.3-1 Power Dependent LHGRFAC (P) Multiplier (Technical Specification Reference 3.11 .B)

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LHGR Flow Factor LHGRFAC (F)

1. On z1 TIT T- r- I 1.00 _ _ _

Maximum Flow =109.5%

0.90 U

0 0.80 0.70 -

0 LHGR (F) - LHGRFAC (F) x LHGRstd LHGRstd - STANDARD LHGR LIMITS r- 0.60 _

For W (%/.Rated Core Flow) > 30%

And Max Runout Flow S 109.5Ne 0.50 .

LHGRFAC (F) - The Minimum of EITHER 1.0 OR (0.8737 x (WV/100) + 0.2779) 0.40 - %Rated Core Flow 0.30 20 30 40 50 60 70 80 90 100 110 120 Core Flow (%/.Rated)

Figure 2.3-2 LHGR Flow Factor LHGRFAC (F)

(Technical Specification Reference 3.1 1.13)

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CYCLE 25 POWER/FLOW MAP 110 100 90 80 la 70 60 50 0

a.

40 30 20 10 0

0 10 20 30 40 50 60 70 80 90 100 110 Core Flow (%Rated)

Figure 2.4-1.

Limits of Power/Flow Operation (Technical Specification Reference 3.6.J)

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3.0 REFERENCES

3.1. Report, General Electric, General Electric Standard Application for Reactor Fuel (GESTAR II), NEDE-2401 1-P-A-14, June 2000 (Proprietary).

3.2. Report, GE, Vermont Yankee Nuclear Power Station APRM/RBM/Technical Specifications/Maximum Extended Load Line Limit Analysis (ARTS/MELLLA),

NEDC-33089P, March 2003 (Proprietary).

3.3. Report, GE, Entergv Nuclear Operation Incorporated Vermont Yankee Nuclear Power Station Extended Power Uprate - Task T0407 - ECCS-LOCA SAFER/GESTR, GE-NE-0000-001 5-5477-01, July 2003.

3.4. Report, Vermont Yankee Nuclear Power Station Increased Core Flow Analysis, NEDC-32791 P. February 1999.

3.5. Letter, Global Nuclear Fuels, William H. Hetzel (GNF) to Dave Mannai (VYNPC),

Vermont Yankee Option B Licensing Basis, WHV: 2001-023, November 9, 2001.

3.6. Report, Global Nuclear Fuels, Supplemental Reload Licensing Report for Vermont Yankee Nuclear Power Station Reload 24 Cycle 25. 0000-0035-6435-SRLR, Rev. 0, September 2005.

3.7. Report, Global Nuclear Fuels, Fuel Bundle Information Report for Vermont Yankee Nuclear Power Station Reload 24 Cycle 25 0000-0035-6435-FBIR, Rev. 0, September 2005 (Proprietary).

3.8. VYDC 2003-015, ARTS/MELLLA Implementation.

3.9. Report, GE, Vermont Yankee Nuclear Power Station Single Loop Operation, NEDO-30060, February 1983.

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