ML20065E909
| ML20065E909 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 03/31/1994 |
| From: | VERMONT YANKEE NUCLEAR POWER CORP. |
| To: | |
| Shared Package | |
| ML20065E877 | List: |
| References | |
| NUDOCS 9404110149 | |
| Download: ML20065E909 (9) | |
Text
Appendix 2 Core Operatino Limits Report Chances for Stability Affected Paces 111 iv vi 1
4 11 13 1
9404110149 940331 PDR ADOCK 05000271 P
ABSTRACT This report presents the cycle-specific operating limits for the operation of Cycle 17 of the Vermont Yankee Nuclear Power Station. The limits are the maximum average planar linear heat generation rate, maximum linear heat generation rate, minimum critical power ratio and stability power flow exclusion region, l
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TABLE OF CONTENTS Pace ABSTRACT iii i
i LIST OF' FIGURES vi
1.0 INTRODUCTION
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2.2 Minimum Critical Power Ratio Limits.
3 2.3 Maximum Linear Heat Generation Rate Limits 3
1 2.4 Thermal Hydraulic Stability Limits 4
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LIST OF FIGURES Number Title Pace Figure 2.2-1 Kr Versus Percent of Rated Flow 10 Figure 2.4-1 Stability Power and Flow Exclusion Region 11 l
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1.0 INTRODUCTION
4 This report provides the cycle-specific limits for operation of the Vermont Yankee Nuclear Power Station in Cycle 17.
It includes the limits for the maximum average planar linear heat generation rate, maximum linear heat generation rate, minimum critical power ratio, and thermal hydraulic stability.
If any of these limits are exceeded, action will be taken as defined in the Technical Specifications.
This report has been prepared in accordance.with the requirements of Technical Specification 6.7.A.4.
The core operating limits have been developed using the NRC-approved methodologies listed in References 1 through 29, 33 and 34, and in Technical Specification 6.7.A.4.
The bases for these limits are in Reference 12, 17, and 30 through 34. n4ous
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will verify that these lattice MAPLHGR limits are not violated. Tables 2.1-1 through 2.1-4 provide a limiting ccmposite of MAPLHGR values for oach fuel type, which envelope the lattice MAPLHGR values employed by the process f
computer. When hand calculations are required, these MAPLHGR values are used for all lattices in the bundle.
2.2 Minimum Critical Power Ratio Limits l
During steady-state power operation, the Minimum Critical Power Ratio (MCPR) shall be equal to, or greater than, the limits shown in Table 2.2-1.
The MCPR limits are also valid during coastdown beyond 10760 mwd /St.
For single recirculation loop operation, the MCPR limits at rated flow shall be the values from the Table listed under the heading, " Single Loop Operation." The single loop values are obtained by adding 0.01 to the two loop operation values. For core flows other than the rated condition, the l
MCPR limit shall be the appropriate value from Table 2.2-1 multiplied by K,,
where K, is given in Figure 2.2-1 as a function of the flow control method in use.
These limits are only valid for the fuel types in Cycle 17, 2.3 Maximum Linear Heat Generation Rate Limits During steady-state power operation, the Linear Heat Generation Rate (LHGR) of any rod in any fuel bundle at any axial location shall not exceed the maximum allowable LHGR limits in Table 2.3-1.
This table only lists the limits for fuel types in Cycle 17.
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2.4 Thermal Hydraulic Stability Limits Normal plant operation will not occur inside the bounds of the exclusion region defined in Figure 2.4-1.
These power and flow limits are. applicable for Cycle 17, operation inside of the exclusion region may result in a thermal hydraulic oscillation.
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0 10 20 30 40 50 60 70 80 90 100 110 120 muunum rnnsn TorrAL CORE FLOW (%)
Exclusion Region Boundary Eauation Power = 133.7851 - 6.61 (FI.OW- 0.5) +0.113 (FLOW- 0.5)2
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Figure 2.4-1 Stability Power and Flow Exclusion Region (Technical Specification Rt 'rence 3.6.J) neous t
31.
- Report, M. A.
Sironen, Vermont Yankee Cycle 17 Core Performance Analysis Report, YAEC-1867, June 1993.
32.
- Report, B.
Y. Hubbard, et al., nnd-of-Full-Power-Life Sensitivity Study for the Revised BWR Licensino Methodoloav, YAEC-1822, October 1991.
33.
Report, General Electric Nuclear Energy, BWR Owner's Group Long-Term Solutions Licensing Methodology, NEDO-31960, June 1991.
34.
Report, General Electric Nuclear Energy, BWR Owner's Group Long-Term Solutions Licensing Methodology, NEDO-31960, Supplement 1, March 1992.
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