ML091940085

Luminant RAI 24 and 37, Secondary Line Breaks, Debris Load and Testing

ML091940085
Person / Time
Site:	Comanche Peak
Issue date:	07/09/2009
From:	Luminant Power
To:	Office of Nuclear Reactor Regulation
References
Download: ML091940085 (4)

Text

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a NRC - Luminant Power Public Meeting Comanche Peak Nuclear Power Plant Secondary Line Breaks July 9th 2009 Secondary Line Breaks

• Containment Spray provides containment heat removal - maximum 10 hour1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> mission time for equipment qualification.

Decay heat removal is by the secondary systems (not by ECCS, i.e., 50.46)

• GDC-38 and GDC-41 do not apply Containment Spray is not credited for Part 100

RG 1.82 R3

" "Some PWRs may require recirculation from the sump for licensing basis events other than LOCAs. Therefore, plants should review the licensing basis and include potential break locations in the main steam and main feedwater lines as well in determining the most limiting conditions for sump operation."

• GDC-4 is the Comanche Peak licensing basis for secondary line breaks

• CPNPP elected to evaluate sump performance using the same break selection criteria as for LOCA.

Comparison of Fiber Load Fibrous MSLB (lbs)

Prototype (lbs)

LOCA (lbs)

Bounded Latent Fiber 24 30 24 Yes LDFG Fines 42.6 53.8 Yes LDFG Smalls 160 540.75 183 Yes LDFG Large 18.4 LDFG Intact 18.6 Kaowool 353.6 448.8 Prototype Sil-temp 52.4 71.4 Prototype Min-K 12.96 8

1.6 No Covers 27.2 Total 645.6 1099 218.8 Prototype

Comparison of Particulate Load MSLB (lbs)

Prototype (lbs)

LOCA (lbs)

Bounded Dirt/Dust 136 170 136 Yes Min-K Fines 52.16 34.3 lbs 6.72 No Acceptable Epoxy 217.5 3860.9 262.9 Yes Acceptable IOZt 366.9 267.5 376 Yes Unqualified Epoxy 2838 (6 mil) 12920 lbs as 2838 (6 mil)

Yes.

(outside ZOI) particulate fines (walnut shells)

Unqualified IOZ Yes (outside ZOI) 16834 25634 16834 Unqualified Alkyd Yes (outside ZOI) 104 992 104 Total 20, 549 43,879 20,557.6 Yes Prototype (small flume) Testing

• Ultra-Conservative test temperature - < 50 F

" Fiberglass fibers settle in 20 to 60 minutes in 50 F water versus 20 to 30 seconds in 120 F water

[NUREG/CR-2982, "...water temperature has a paramount effect on buoyancy..."]

• Tests conducted at 128 F and 169 F confirmed the effect on settling of fiberglass [Test Report No. ITR-92-03N]

• MSLB Head Loss - Small Flume 0.005 ft. (0.0044 fps)

• LOCA Head Loss - Small Flume 0.4682 ft. (0.0073 fps)

• LOCA Head Loss - Large Flume 0.6 ft. (0.0073 fps)

RAI 13

Conclusion

• Debris Generation and Transport analyses were performed consistent with the SER for NEI 04-07

" Prototype testing showed that LOCA debris loads and conditions bounded the secondary break head loss

" Large flume testing under the March 2008 protocol confirmed the the small flume test protocol was conservative for this case

" CPNPP has provided reasonable asurrance, that the Containment Spray System wil perform its design function for secondary line breaks