ML21278A238

2 to Updated Final Safety Analysis Report, Chapter 10, Appendix 10A, Section 10A.6, Shutdown Cooling

ML21278A238
Person / Time
Site:	Calvert Cliffs
Issue date:	09/07/2021
From:	Exelon Generation Co
To:	Office of Nuclear Reactor Regulation
Shared Package
ML21278A102	List: ML21257A249 ML21257A253 ML21257A254 ML21257A255 ML21257A256 ML21257A258 ML21257A259 ML21257A260 ML21257A261 ML21257A262 ML21257A263 ML21257A264 ML21257A265 ML21257A267 ML21257A268 ML21257A269 ML21257A278 ML21257A281 ML21257A282 ML21257A283 ML21257A284 ML21257A285 ML21257A286 ML21257A287 ML21257A288 ML21257A289 ML21257A298 ML21257A299 ML21257A300 ML21257A301 ML21257A302 ML21257A303 ML21257A304 ML21257A305 ML21257A306 ML21278A106 ML21278A107 ML21278A108 ML21278A109 ML21278A110 ML21278A111 ML21278A112 ML21278A113 ML21278A114 ML21278A115 ML21278A116 ML21278A117 ML21278A118 ML21278A122 ML21278A123 ... further results
References
NEI 99-04
Download: ML21278A238 (2)

Text

10A.6 SHUTDOWN COOLING The SDC System is used to cool the Reactor Coolant System from 300F to 140F. The maximum temperature and pressure at which SDC can be initiated is 300 psig and 300F.

The SDC mode is a manually-initiated operation and is under strict administrative control during the entire cooldown period of approximately 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. It is further noted that the SDC System conditions are above 200F and 275 psig for less than 2% ofthe total operating time.

Based on the level of quality control, periodic ISI, the low usage factor, the short time this system exceeds 200F and 275 psig, and the strict administrative control of the SDC System, a break in this system is not considered credible.

10A.6.1 PIPE WHIP Since no pipe breaks or critical cracks are considered credible due to short duration, no pipe whip is considered.

10A.6.2 PIPE BREAK LOCATION Not applicable (Section 10A.6.1).

10A.6.3 PIPE BREAK ORIENTATION Not applicable (Section 10A.6.1).

10A.6.4 DYNAMIC ANALYSIS Not applicable (Section 10A.6.1).

10A.6.5 PIPE WHIP, JET IMPINGEMENT, AND REACTIVE FORCES PROTECTION No protective measures are required.

10A.6.6 SEISMIC CATEGORY I STRUCTURE EVALUATION Since a break in this system is not considered credible, there will be no additional loading to affect the adequacy of Category I structures. Category I structure are designed in accordance with the design bases shown in Appendix 5A of the UFSAR.

10A.6.7 STRUCTURAL DESIGN LOADS There will be no additional loads on the Category I structures or structural components because a break in this line is not considered to be credible. All Category I structures are designed using loads combinations listed in Appendix 5A of the UFSAR.

10A.6.8 ANALYSIS OF REVERSAL OF LOADS Not applicable (Section 10A.6.1).

10A.6.9 STRUCTURAL EFFECT OF OPENINGS ADDED TO THE STRUCTURES No new openings are required.

10A.6.10 VERIFICATION THAT ANY STRUCTURAL FAILURE WILL NOT AFFECT OTHER STRUCTURES REQUIRED FOR SAFETY No structures will fail (Section 10A.1.10).

10A.6.11 VERIFICATION THAT PIPE RUPTURE WILL NOT AFFECT SAFETY Not applicable (Section 10A.6.1).

CALVERT CLIFFS UFSAR 10A.6-1 Rev. 47 10A.6.12 EFFECT ON CONTROL ROOM Since there are no postulated ruptures in the system piping, therefore, there will be no effect on the Control Room.

10A.6.13 ENVIRONMENTAL QUALIFICATION OF AFFECTED REQUIRED EQUIPMENT Not applicable (Section 10A.6.1).

10A.6.14 DESIGN DIAGRAMS AND DRAWINGS Since no changes are required in this system, no design diagrams or drawings are included.

10A.6.15 FLOODING Not applicable (Section 10A.6.1).

10A.6.16 QUALITY CONTROL AND INSPECTION PROGRAM The quality control and inspection programs are presented in Section 10A.1.16.

10A.6.17 LEAK DETECTION Not applicable (Section 10A.6.1).

10A.6.18 EMERGENCY PROCEDURES Not applicable (Section 10A.6.1).

10A.6.19 SEISMIC AND QUALITY CLASSIFICATION The SDC System is designed and constructed to meet ANSI B31.7, Class I requirements.

The system is also designed to withstand an SSE in combination with normal design loads.

10A.6.20 DESCRIPTION OF ASSUMPTIONS, METHODS, AND RESULTS OF ANALYSIS FOR PRESSURE AND TEMPERATURE TRANSIENTS IN COMPARTMENTS Not applicable (Section 10A.6.1).

10A.6.21 DESCRIPTION OF ASSUMPTIONS, METHODS, AND RESULTS OF ANALYSIS FOR EFFECT ON PRIMARY OR SECONDARY CONTAINMENT STRUCTURE DUE TO PIPE RUPTURE Not applicable (Section 10A.6.1).

CALVERT CLIFFS UFSAR 10A.6-2 Rev. 47