LR-N17-0034, Salem Generating Station, Units 1 & 2, Revision 29 to Updated Final Safety Analysis Report, Chapter 5, Sections 5.3.1 to 5.3-2

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Salem Generating Station, Units 1 & 2, Revision 29 to Updated Final Safety Analysis Report, Chapter 5, Sections 5.3.1 to 5.3-2
ML17046A355
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Site: Salem  PSEG icon.png
Issue date: 01/30/2017
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Public Service Enterprise Group
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Office of Nuclear Reactor Regulation
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LR-N17-0034
Download: ML17046A355 (2)


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5.3 THERMAL HYDRAULIC SYSTEM DESIGN 5.3.1 Analytical Methods and Data The thermal and hydraulic design bases of the Reactor Coolant System (RCS) are described in Section 4. 5.3.2 Operating Restrictions on Pumps The minimum net position suction head (NPSH) and minimum seal ection flow rate must be established before operating the reactor coolant pumps. Requirements are set forth in the pump operating instructions. 5.3.3 Temperature Power Operating Map Reactor power is controlled to maintain average coolant temperature at a value which is a linear function of load. 5.3.4 Load Following Characteristics Load following is discussed in Section 5.2.1.5.2. 5.3.5 Transient Effects Transient effects on the RCS are evaluated in Section 15. 5.3.6 Thermal and Hydraulic Characteristics Summary Table The thermal and hydraulic characteristics are given in Tables 4.3-1, 4. and 4.4-2. 5.3.7 Natural Circulation Capability The capability to perform natural circulation cooldown has been analyzed following a transient in a Pressurized Water Reactor of different design in which significant void formation occurred in the reactor vessel head. The took into account such factors as the amount of flow to the upper head region, RCS cooldown/depressurization rate, heat removal via the Control Rod Drive Mechanism (CRDM) cooling fans and ambient losses. Salem is a "T-Hot" plant, i.e., one in which the upper head water is assumed equal to the hot leg temperature. Analysis results are summarized below. 5.3-1 SGS-UFSAR Revision 24 May 11, 2009 I The average cooldown rate of the upper head fluid due to the 25°F per hour natural circulation cooldown rate is about 10°F per hour. The total upper head cooldown rate due to both the natural circulation cooldown and the CRDM fans varies from 31°F per hour initially to around 21°F per hour when the upper head temperature is cooled to 350°F. Thus, with the CRDM fans operating during the cooldown with no void formation in the upper head area, the operator is required to maintain a minimum of subcooling during the depressurization. A Salem-specific analysis has been performed to determine the natural circulation cool down strategy to prevent void formation without CRDM fans in operation. Without the CRDM fans in operation, the can be cooled down to Residual Heat Removal (RHR) conditions at a natural circulation cooldown rate of 25°F per hour with no void formation occurring in the upper head with appropriate precautions being taken by the operators. The operator is required to maintain a minimum of 50°F subcooling until the primary system pressure reaches 50 psi below the permissive to block SI. After the automatic injection are blocked, the establishes 200°F (approximately 430°F in the hot leg) and maintains at least 200°F subcooling (or the Technical Specification limit if it is more restrictive) to a primary system pressure of 1200 psig. Depressurization is stopped at 1200 psig and the cooldown is continued until the system is less than 350°F. At this point, the is to wait for 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> to allow the upper head to cool off, corresponding to a saturation temperature less than the RHR cut-in pressure (325 psig). Finally, the primary system is depressurized to 325 psig and the RHR System used for further cooldown. Unit 1 has Model-F steam generators which are similar in design to the Series 51 in natural circulation capabilities. Hence, the general conclusions drawn above are also applicable to Unit 1 with the Model-F steam generators. The Unit 2 AREVA NP Model 61/19T steam have natural circulation capability to remove decay heat. 5.3-2 SGS-UFSAR Revision 24 May 11, 2009