ML20098B054
| ML20098B054 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 09/22/1995 |
| From: | Tuckman M DUKE POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9510020092 | |
| Download: ML20098B054 (6) | |
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DeePbwerCompany MSnma P.0 Box 1006 Senior Vicehesident Garlotte.NC2820H006 NuclearGeneration
. (704)382220000 ice (704)3824360 Fax DUKEPOWER September 22,1995 -
.s U. S. Nuclear Regulatory Commission Washington, D. C. 20555 -
Attention: Document ControlDesk
Subject:
McGuireNuclear Station Docket Numbers 50-369 and -370 Proposed Fuel Ent'chment Increase; Supplemental Response to Request for Additional Information
~ Attached is additional information regarding spent fuel pool cooling, to supplement the responses provided in Duke's July 21,1995 letter.
If any additional information is needed, please call Scott Gewehr at (704) 382-7581.
Very tmly yours, j $.
W"m
. M. S. Tuckman cc:
Mr. '. Nerses, Project Manager Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Conunission Mail Stop 14H25, OWFN Washington, D. C. 20555 020097 40
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V 9510020092 950922 g
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PDR ADOCK 05000369 P
l U. S. Nucl' ear Regulatory Commission September 22,1995 Page 2 l
Stuart D. Ebneter, Regional Administrator U.S. Nuclear Regulatory Commission - Region II 101 Marietta Street,NW-Suite 2900 Atlanta, Georgia 30323
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Mr. G. F. Maxwell i
Senior Resident Inspector l
McGuire Nuclear Station i
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ATTACHMENT 1 RcePONSE TO REQUEST FOR ADDITIONAL INFORMATION (8/10/95)
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1 McGUIRE PROPOSED FUEL ENRICHMENT INCREASE j
1)
Heat Transfer The heat transfer rate UAF (Heat transfer coefficient X Heat transfer area X Correction factor) is based on certain minimum flow rates of spent fuel pool (SFP) water and component cooling (CCS) water going through the tubes and shell of the HX. Accordingly, show that the values of UAF used in calculating the SFP coolant temperatures shown in Table A2-3 of the July 21,1995 submittal are conservanve.
The values of UAF are based on design data for the heat exchanger assuming maximum fouling. Informal testing performed on 4/7/93 indicated that the design data assumed is conservative. Specifically, the heat transfer coefficient, U, for heat 2
exchanger 2B determined from the measured data is approximately 460 BTU /hr ft,
2 while the r.ssumed value is 321 BTU /hr ft. Incomplete data was taken on the other heat exchangers. This data indicated that their performance was similar to the 2B heat exchanger. Therefore, the values of UAF used in calculating the SFP coolant temperatures shown in Table A2-3 are considered conservative.
4 2)
Cooling Time Regarding the cooling time for the fuel elements removed from the core and placed in the SFP, Table A2-1 shows that it takes 7 day (168 hours0.00194 days <br />0.0467 hours <br />2.777778e-4 weeks <br />6.3924e-5 months <br />) to place 76 fuel elements in the SFP for the normal reload case (Table A2-1 in the July 21 submittal),
and 150 hours0.00174 days <br />0.0417 hours <br />2.480159e-4 weeks <br />5.7075e-5 months <br /> (Table A2-2) for 193 fuel elements when removing a full core. Justify this apparent discrepancy, and make any corrections that are required.
The initial cooling time in Tables A2-1 and A2-2, for the normal and maximum heat loads, are both in error. The decay heat calculations were both based on 6.5 days, or 156 hours0.00181 days <br />0.0433 hours <br />2.579365e-4 weeks <br />5.9358e-5 months <br />. The 6.5 day initial cooling time is a conservative estimate of the earliest time that fuel assemblies could be moved from the reactor into the spent fuel pool.
Corrections to these tables are provided, j
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j 3)
Deionizer Show how the deionizer resins are protected against high SFP coolant temperatures.
In the event of a loss of SFP cooling at McGuire, the demineralizer is not specifically isolated. Loss of SFP cooling could occur in one of two ways; either loss of both i
SFP cooling pumps, or loss of component cooling, which cools the SFP heat exchanger. If both SFP cooling pumps are lost, there is no flow through the demineralizer, and therefore no need to isolate it. In the case ofloss of component cooling there would still be SFP cooling flow, but sufficient time exists to take the corrective actions for restoring either A or B train of component cooling to the SFP heat exchanger. The heatup rate, even with a fresh core in the pool, is still slow enough to allow ample time for restoring component cooling before any breakdown i
of the resin in the demineralizer. Typical temperatures in the spent fuel pool are 90-100 F; the worst-case heatup rate is =16.7 F/hr. Computer indications of low component cooling (KC) flow are available from a variety of sources, including:
outlet from SFP heat exchangers; Chemical and Volume Control System heat exchangers (also annunciator alarm); each reactor coolant pump upper and lower bearing cooler (also annunciator alarm); and high temperature indications on the many components served by KC.
In addition, the SRO is aware that at about 140 *F, the resin in the demineralizer would begin to breakdown. However the SRO also felt there was adequate direction in the loss of spent fuel pool cooling procedure for restoring cooling.
Furthermore, Chemistry would have been notified of the abnormal conditions and between the two groups, there are adequate responses for this situation.
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Sheeti (Table A2-1 l l
Normal Maximum Heat Load 76 Feed Batch 2
Bumup EFPD Discharged Total heatload heatioad (D_ays)
Enrichment (mwd /MTU)
Assemblies Discharged (BTU /Hr)
(BTU /Hr) 65 4.150 47277 1234.022 44 44 8.21 E+06 8.27E+06 4.400 42501 1109.359 32 76 5.95E+06 7.07E+06 579 4.150 47277 1234.022 44 120 5.49E+05 6.89E+05 4.400 42501 1109.359 32 152 3.88E+05 4.71 E+05 1121 4.150 47277 1234.022 44 196 3.19E+05 3.36E+05 4.400 42501 1109.359 32 228 2.24E+05 2.26E+05 1664 4.150 47277 1234.022 44 272 2.58E+05 1.98E+05 4.400 42501 1109.359 32 304 1.80E+05 1.32E+05 2207 4.150 47277 1234.022 44 348 2.37E+05 1.42E+05 i
4.400 42501 1109.359 32 380 1.65E+05 9.45E+04 2749 4.150 47277 1234.022 44 424 2.26E+05 1.21 E+05 4.400 42501 1109.359 32 456 1.57E+05 8.02E+04 3292 4.150 47277 1234.022 44 500 2.17E+05 1.07E+05 4.400 42501 1109.359 32 532 1.51 E+05 7.11 E+04 3834 4.150 47277 1234.022 44 576 2.09E+05 9.59E+04 4.400 42501 1109.359 32 608 1.46E+05 6.38E+04 4377 4.150 47277 1234.022 44 652 2.02E+05 8.62E+04 4.400 42501 1109.359 32 684 1.41 E+05 5.73E+04 4920 4.150 47277 1234.022 44 728 1.95E+05 8.11 E+04 4.400 42501 1109.359 32 760 1.36E+05 5.39E+04 5462 4.150 47277 1234.022 44 804 1.88E+05 7.80E+04 4.400 42501 1109.359 32 836 1.31 E+05 5.19E+04 6005 4.150 47277 1234.022 44 880 1.81 E+05 7.35E+04 4.400
_4_2501 1109.359 32 912 1.26E+05 4.89E+04 6548 4.150 47277 1234.022 44 956 1.75E+05 7.08E+04 4.400 42501 1109.359 32 988 1.22E+05 4.71 E+04 j
7090 4.150 47277 1234.022 44 1032 1.69E+05 6.76E+04 j
4.400 42501 1109.359 32 1064 1.18E+05 4.50E+04 7633 4.150 47277 1234.022 44 1108 1.63E+05 6.52E+04 4.400 42501 1109.359 32 1140 1.14E+05 4.34E+04 8175 4.150 47277 1234.022 44 1184 1.57E+05 6.29E+04
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4.400 42501 1109.359 32 1216 1.10E+05 4.18E+04 l
8718 4.150 47277 1234.022 44 1260 1.52E+05 6.07E+04 4.400 42501 1109.359 32 1292 1.06E+05 4.03E+04 9261 4.150 47277 1234.022 44 1336 1.47E+05 5.85E+04 4.400 42501 1109.359 32 1368 1.02E+05 3.89E+04 9804 4.150 47277 1234.022 44 1412 1.41 E+05 5.62E+04 4.400 42501 1109.359 32 1444 9.85E+04 3.73E+04 10347 4.150 47277 1234.022 19 1463 5.87E+04 2.34E+04 Total Heat load for Full Pool in storago mode BTU /hr 2.08E+07 1.95E+07 Page 1
Sheet 1 jTable A2-2 l
Maximum Heat Load 76 Feed Batch BTP 9-2 ANS 5.1 Cooling Bumup EFPD Discharged Total Heat Load Heat Load (Days)__ Enrichment mwd /MTU Assemblies Discharged (BTU /Hr)
(BTU /Hr) 6.5 4.150 1143 29.5 44 44 4.73E+06 4.33E+06 4.400 978 25.24 32 76 3.26E+06 2.94E+06 4.150 23158 597.72 44 120 7.95E,06 8.05E+06 4.400 20015 516.6 32 152 5.72E+06 5.77E+06 4.150 39263 1013.4 20 172 3.71 E+06 3.83E+06 4.400 37219 960.05 12 184 2.22E+06 2.28E+06 4.400 435G6 1125.24 8
192 1.49E+06 1.54E+06 4.400 "45115 1164.45 1
193 1.86E+05 1.93E+05 36 4.150 47277 1234.022 44 237 3.98E+06 3.96E+06 4.400 42501 1109.359 32 269 2.88E+06 2.85E+06 579 4.150 47277 1234.022 44 313 5.49E+05 6.89E+05 4.400 42501 1109.359 32 345 3.88E+05 4.71 E+05 1121 4.150 47277 1234.022 44 389 3.19E+05 3.36E+05 4.400 42501 1109.359 32 421 2.24E+05 2.26E+05 1664 4.150 47277 1234.022 44 465 2.58E+05 1.98E+05 4.400 42501 1109.359 32 497 1.80E+05 1.32E+05 2207 4.150 47277 1234.022 44 541 2.37E+05 1.42E+05 4.400 42501 1109.359 32 573 1.65E+05 9.45E+04 2749 4.150 47277 1234.022 44 617 2.26E+05 1.21 E+05 4.400 42_5_01 1109.359 32 649 1.57E+05 8.02E+04 3292 4.150 47277 1234.022 44 693 2.17E+05 1.07E+05 4.400 42501 1109.359 32 725 1.51 E+05 7.11 E+04 38_34 4.150 47277 1234.022 44 769 2.09E+05 9.59E+04 4.400 42501 1109.359 32 801 1.46E+05 6.38E+04 4377 4.150 47277 1234.022 44 845 2.02E+05 8.62E+04 4.400 42501 1109.359 32 877 1.41 E+05 5.73E+04
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4920 4.150 47277 1234.022 44 921 1.95E+05 8.11 E+04
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4.400 42501 1109.359 32 953 1.36E+05 5.39E+04 5462 4.150 47277 1234.022 44 997 1.88E+05 7.80E+04 4.400 42501 1109.359 32 1029 1.31 E+05 5.19E+04 6005 4.150 47277 1234.022 44 1073 1.81 E+05 7.35E+04 4.400 42_501 1109.359 32 1105 1.26E+05 4.89E+04 6548 4.150 47277 1234.022 44 1149 1.75E+05 7.08E+04 4.400 42501 1109.359 32 1181 1.22E+05 4.71 E+04 7090 4.150 47277 1234.022 44 1225 1.69E+05 6.76E+04 4.400 42501 1109.350 32 1257 1.18E+05 4.50E+04 7633 4.150 47277 1234.022 44 1301 1.63E+05 6.52E+04 4.400 42501 1109.359 32 1333 1.14E+05 4.34E+04 8175 4T50 47277 1234.022 44 1377 1.57E+05 6.29E+04
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4.400 42501 1109.359 32 1409 1.10E+05 4.18E+04 8718 4.150 47277 1234.022 44 1453 1.52E+05 6.07E+04 4.400 42501 1109.359 10 1463 3.31 E+04 1.26E+04 Maximum Pool Heat Load Btu /Hr 4.22E+07 3.96E+07 Page 2