ML20214G648
| ML20214G648 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 05/16/1974 |
| From: | Tedesco R US ATOMIC ENERGY COMMISSION (AEC) |
| To: | Deyoung R US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| CON-WNP-0070, CON-WNP-70 NUDOCS 8605220361 | |
| Download: ML20214G648 (3) | |
Text
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g=-n MAY 161974 x
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eket No. 50-397
?
. C.
h'r_,, Assistant Director for Light Water Beactors, Creup 1, L WFFSS 2 - SACRIFICIAL SEIELD ANMULUS FRESgURE RESPONSE (TAR-908) l 1
Plant Mane WFFSS Nuclear Project No. 2 Docket No.:
50-397 Licensing Stage: Fost-CP Froject Manager:
J. Orndoff Requested Completion Date: May 15, 1974 Technical Review By: Containment Systema Branch Description of Task: Review of Sacrificial Shield Pressure Basponse Review Status: Awaiting Information In response to your technical assistissce request of April 12. 1974, the Containment Systems Branch has reviewed the infetuation provided by the i
applicant regarding the pressure response of the sacrificial shield annulus. We find that additional information is required for us to complete our review as specified in the enclosed question list.
We also note that our review of the VFFSS-2 shield annulus will include the potential effects of spatial pressure variations within the annulus region. This was found to be a significant consideration in the analysis of PWR reactor cavities and subcompartments and is being applied in analogous situations on BWR's.
Original sirned by:
i Robert L. Tedesco l
Robert L. Tedesco Assistant Director for Containment Safety
(
I Directorate of Licensing
Enclosure:
As stated i
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R. Klecker C. Lainas L - Reading J. Eendrie D. Eisenhut R. Cudlin CS - Reading S. Hanauer J. Carter CSB - Reading W. Lutler S. Varga Docket File No.
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REQUEST FOR ADDITIONAL INFORMATION WPPSS - 2 DOCKET NO. 50-397 1.
With regard to the method of analysis for the sacrificial shield annulus pressure responses provide the name and a description of the blowdown and pressure a.
transient code (s) used it. the analyr.is; b.
justify the blowdown model used sh'owing that it adequately represents the short-term mass and energy release rates; c.
provide and justify, preferably by comparison with experimental data, the equations or correlations used to calculate ficw between compartments.
Include a discussion of the critical flow model and discharge coefficient applied to critical flow; d.
discuss the method of treating the air-steam-water mixture in subcompartment thermodynamics and fluid dynamics.
2.
Provide the following additional information with respect to the results of the sacrificial shield annulus pressure analysis:
a.
Provide a table of the blowdown mass and energy release rates used in the analysis; b.
Provide and justify the break type and area used in the analysis; c.
Provide sufficiently detailed drawings showing the strangement of the reactor vessel, sacrificial shield, insulation, and recirculation line from which subcompartment volumes and vent areas can be determined.
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d.
1% scribe the nodalization sensitivity studies performed to determine the minimum number of volume nodes required to conservativelypredictthemaximumpressureforthesacrificibl shield annulus. These studies should include, consideration of spatial, pressure variation; i.e., pressure variations cir-cumferentially, axially and radially within the annulus.
~
Provide a schematic flow diagram sh ging the nodalization of e.
the shield, annulus and specifying nodal net f ree volumes and i
interconnecting flow path areas.
f.
Provide and justify values of vent loss coef ficients and/or frictionfactorsusedtocal'hulate[flowbetweennodalvolumes.
9 When a loss coefficient consists of more than one ccmponent (e.g.,
entrance loss, exit loss)/ident'ify each component and its value.
g.
Discuss the manner in which movabic obstructions to vent flow (such an insulation, ducting, plugs and seals) were treated.
Include analytical justification if credit is taken for t'ae removal of such itecis to obtain vent area. Justify your assumption that vent areas will not be more than 50% plugged by insulation or other' displaced objects.
h[ Provide a curve of shield differential pressure 'as a function oftimeindicating4patialreshonsewhere' appropriate.
1.
Specify the det.ign differential pressure of the sacrificial shield.
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