ML20077F415

an Analysis of Core Meltdown Accidents in CE Sys 80+ Plant Using Melcor,

ML20077F415
Person / Time
Site:	05200002
Issue date:	07/31/1994
From:	Nimnual S, Yang J BROOKHAVEN NATIONAL LABORATORY
To:	Office of Nuclear Reactor Regulation
Shared Package
ML20076E998	List: ML20076E995 ML20076E999 ML20077F411 ML20077F415 ML20077F416 ML20077F425
References
CON-FIN-J-2022 J2022-04669, J2022-4669, NUDOCS 9412140065
Download: ML20077F415 (297)

Text

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l J2022-04669 7/94 l

l AN ANALYSIS OF CORE MELTDOWN ACCIDENTS IN THE CE SYSTEM 80+ PLANT USING MELCOR S. NIMNUAL 1 i

J.W. YANG July 1994 Safety and Risk Evaluation Division l

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l 9412140065 941209 PDR ~ ADOCK 05200002 i A PDR j

j.

AN ANALYSIS OF CORE MELTDOWN ACCIDENTS IN THE CE SYSTEM 80+ PLANT USING MELCOR S. Nimnual J. W. Yang P

Safety and Risk Evaluation Division Department of Advanced Technology Brookhaven National Laboratory Upton, New York July 1994 Prepared for Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, DC 20555 Contract No. DE-AC02-76CH00016 FIN J-2022

'l ABSTRACT An analysis of severe accidents for the CE system 80+ standard plant design was performed to study the impact of core-concrete interaction (CCI) on the containment's performance. The MELCOR code (version 1.8.2) was used for the calculations. CCI may cause the containment to fail by over-pressurization from steam and non-condensible gases or the core debris may melt-through the basemat. Four accident sequences were selected for the study; a station blackout sequence, a small-break loss-of-coolant accident, a medium break loss-of-coolant accident, and a steam-generator tube rupture accident.

A sensitivity study based on these sequence also was made to assess the impact of a.) the availability of the cavity flooding system, b.) the type of concrete in the cavity, c.) the number of steam generator tubes ruptured, and d.) the operation of the containment spray.

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i TABLE OF CONTENTS

1. Introduction . . . . . . . . . . .......... .... ............................... ... 1 1.1 Background and Objective . . . . ......................................... I 1.2 MELCOR . . . . . . . . . . . . . . . ................................... ... 1 13 Organization ........... .... ....... ......... ....... ............ 2

2. Plant Description . . . . . .................................................... 3 2.1 Overall Plant Description . . . . . . . . . . . . . . . . . . . . . . . . . . ................... 3 2.2 Nuclear Steam Supply System ............................. ............ 3 2.2.1 Co re D e sign . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ....... 3 2.2.2 Reactor Internal Structures ........................ ............. 4 2.23 Reactor Coolant System . . . . . . . . . . . .... . ..................... 4 23 Engineered Safety Features . . . . . ....... ........... ......... .. ..... 5 23.1 Containment Structure Design . . ............... ................ 5 2.3.2 Safety Injection System . . . . . . . . . .. ... ...... .... .. .... 6 233 Safety Depressurization System ... ........... ...... ........... 6 23.4 Containment Spray System . . . . . . . . . . . . . . .... .. .. ........... 6 23.5 Emergency Feedwater System . . . . . . . . . . . . . .. ... ............... 6 2.4 In-Containment Water Storage System . . . . . . . . . . . . . . . . . . . . . . ....... ... 7 2.4.1 In. Containment Refueling Water Storage Tank and Holdup Volume Tank . . . ............. .. .... .. ...... 7 2.4.2 Steam Relief System . . ...... ... ....... ........... ... ... 7 2.43 Cavity Flooding Systera . . . . . . . . . . . . . . . . . . . . . ..... .... ......... 7

3. Accident Sequence . . . . . . . . . . . . . . . . . . ...................... . . ...... 19 3.1 Station Blackout Sequence . . . . . . . . . . . . . . . . . . . . . . . . . ...... ........... 19 3.2 Small. Break Loss-of-Coolant Sequence . . . . . . . . . . . ................. .... 19 33 Medium. Break Loss-of. Coolant Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 3.4 Steam Generator Tube Rupture Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

4. MELCOR Input ..........................................................21 4.1 Core Nodalization . . . . . . . . . . . . . . . . . . . . . . . . .. ....... . . . . . . . . . . . 21 4.2 Reactor Coolant System . . . . . . . . . . . . . . . . . . . . . . . . . . ............. . . . . . 21 43 Containment and Engineered Safety Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 4.4 Radionuclides Model . . . . . . . .. ........ .... . ... ... . . . . . . . . . 22

5. MELCOR Results . . . . . . . . . . . . . . . . ..... ............. ................... 35 5.1 Station Blackout Sequence . . . . . . . . . . . . . . . . . . . . . . .................. ... 35 5.2 Small. Break Loss-of-Coolant Sequence . . ....... ..... . . ........... 36 53 Medium. Break Loss-of-Coolant Sequence . . . . . . . . . . . . . ... ............... 38 5.4 Steam Generator Tube Rupture Sequence . ................. .... ....... 40 case 1 SGTR with Functional MSSV ..... ... ..... . . ............ .40 case 2 SGTR with struck open MSSV . . . .. . .. . . .. .. ....... 42 1

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TABLE OF CONTENTS (continued)

....... ....... . . . . . 179 Sensitivity Analysis . . . . . . . ..... ... .

. . . . . 179

6. .............. ................

6.1 Reactor Cavity Flooding . . . . . . . ....... ...... . . . . . . . . . . . . . 182 Basaltic concrete . .......... .............

..... . . . . . . . 183 6.2 . .... .

6.3 Rupture size in SGTR sequence .

........ . . . . . 262 7.

S u m m a ry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

...... . . . . . . . . . . . . . . 264

8. Re fe re n ce s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269 Appendix A. MAAP and MELCOR Modeling Of Corium/ Concrete Interaction i

VI

I LIST OF FIGURES Figure 2.1 CE System 80+ Overall Plant Design ................ ...... ............ 8 Figure 2.2 CE System 80+ NSSS . . . . . . . . .... ................ ....... ......... 9 Figure 2.3 CE System 80+ Reactor Core Assembly ....... .. .. . ........... 10 Figure 2.4 CE System 80+ Reactor Flow Paths .....................................11 Figure 2.5 CE System 80+ Safety Depressurization System ...... .....................12 Figure 2.6 CE System 80+ IRWST and Carving Flooding System Arrangement . . . . . . . . . . . . . 13 Figure 4.1 MELCOR Nodalization for CE System 80+ ..... ... ..... .......... . . . . 23 Figure 4.2 MELCOR Axial Elevation Input Model for CE System 80+ Core and Lower Plenum . 24 Figure 4.3 MELCOR Radial and CEA Ixcation Input Model for CE System 80+ Core and Lower Plenum . . . . . . . . ..... ...................................25 Figure 5.1.1 Vessel Collapsed Liquid Level Predicted by MELCOR for SBO Base Case Sequence . . .... .......... . . . ..... ...........44 Figure 5.1.2 Primary System Pressure Predicted by MELCOR for SBO Base Case Sequence .. ..... ...... .. .... .. . ... ..... 45 Figure 5.1.3 Core Ring 1 (node 110-115) Clad Temperature Predicted by MELCOR for SBO Base Case Sequence . . . ....... ... .. ............ .. 46 Figure 5.1.4 Core Ring 1 (node 104109) Clad Temperature Predicted by MELCOR for SBO Base Case Sequence . ................. ...................... 47 Figure 5.1.5 Core Ring 2 (node 210-215) Clad Tempetature Predicted by MELCOR for SBO Base Case Sequence . . . . . . . . . .... .... .... . ... ....... 48 Figure 5.1.6 Core Ring 2 (node 204 209) Clad Temperature Predicted by MELCOR for SBO Base Case Sequence . . .. . ............. ..... ..... ........ 49 Figure 5.1.7 Core Ring 3 (node 310-315) Clad Temperature Predicted by MELCOR for SBO Base Case Sequence . . . ... . .... . .. . . .. ..... . 50 Figure 5.1.8 Core Ring 3 (node 304 309) Clad Temperature Predicted by MELCOR for SBO Base Case Sequence . . . . ... ........... .. ... ... . . 51 Figure 5.1.9 Core Ring 4 (node 410-415) Clad Temperature Predicted by MELCOR for SBO Base Case Sequence . . . . . . ....... . .. ... .. .. . . .... . . 52 vii

I I LIST OF FIGURES (continued)

Figure 5.1.10 Core Ring 4 (node 404 409) Clad Temperature Predicted by MELCOR for SBO Base Case Sequence .. ......... ..... .... ...... .. .. . . . . . 53 i Figure 5.1.11 Core Support Plate Temperature Predicted by MELCOR for SBO Base Case Sequence . . . . . . .... ... ..... . .... .. . .. . . . . . . . . . . 54 Figure 5.1.12 Lower Head Inner Surface and Penetration Temperatures Predicted by MELCOR for SBO Base Case Sequence . . . . . . . . . . . . .... ..............55 Figure 5.1.13 In-Vessel Hydrogen Production Predicted by MELCOR for SBO Base Case Sequence ............ ............................ . 56 Figure 5.1.14 CCI Cavity Maximum Axial Penetration Predicted by MELCOR for SBO Base Case Sequence . . ........ . ............ .. ............ 57 Figure 5.1.15 CCI Cavity Maximum Radial Penetration Predicted by MELCOR for SBO Base Case Sequence . . . . . . . . .. .. . . . . . . .. .. ..... .. 58 Figure 5.1.16 Cavity Gases Production Predicted by MELCOR for SBO Base Case Sequence .. ... . ....... .... ........ . .. ........ 59 Figure 5.1.17 Containment Pressure Predicted by MELCOR for SBO Base Case Sequence . ......... ........ ...... ... . .. . . . . . . . . 60 Figure 5.1.18 Containment Atmosphere Temperature Predicted by MELCOR for SBO Base Case Sequence . ........... ....... .. . . . 61 Figure 5.1.19 Gaseous Mole Fraction Distributed in Upper Compartment of Containment Predicted by MELCOR for SBO Base Case Sequence . . . . . . . . . . . . . .... . . . 62 Figure 5.1.20 Gaseous Mole Fraction Distributed in Lower Compartment of Containment Predicted by MELCOR for SBO Base Case Sequence . . . . .......... . . . . . . . . 63 Figure 5.1.21 Gaseous Mole Fraction Distributed in Annular Compartment of Containment Predicted by MELCOR for SBO Base Case Sequence . . . . . . .. ... .... . . 64 Figure 5.1.22 Gaseous Mole Fraction Distributed in IRWST Predicted by MELCOR for SBO Base Case Sequence .. ..... .... . . ... ...... . . 65 Figure 5.1.23 Gaseous Mole Fraction Distributed in Cavity Predicted by MELCOR for SBO Base Case Sequence .. . . . . . ... .... .... .. . .. . . . . . 66 Figure 5.2.1 Vessel Collapsed Liquid Level Predicted by MELCOR for S-LOCA Base Case Sequence . . . . . ..... ........ .. ...... ....... . . . . . . . . . . 67 Figure 5.2.2 Core Ring 1 (node 110-115) Clad Temperature Predicted by MELCOR for S-LOCA Base Case Sequence . . ... . .. ... ...... . . . . 68 viii

.i LIST OF FIGURES (continued)

Figure 5.2.3 Core Ring 1 (node 104109) Clad Temperature Predicted by MELCOR for S-LOCA Base Case Sequence . . . . . . . ......... . . . . . . . . . . . . . 69 Figure 5.2.4 Core Ring 2 (node 210-215) Clad Temperature Predicted by MELCOR for S-LOCA Base Case Sequence . . . . . . . ...................... 70 Figure 5.2.5 Core Ring 2 (node 204-209) Clat Temperature Predicted by MELCOR for S-LOCA Base Case Sequence . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . 71 Figure 5.2.6 Core Ring 3 (node 310 315) Clad Temperature Predicted by MELCOR for S-LOCA Base Case Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 Figure 5.2.7 Core Ring 3 (node 304-309) Clad Temperature Predicted by MELCOR for S.LOCA Base Case Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 Figure 5.2.8 Core Ring 4 (node 410-415) Clad Temperature Predicted by MELCOR for S-LOCA Base Case Sequence .... ......... . .... . . . . . 74 Figure 5.2.9 Core Ring 4 (node 404-409) Clad Temperature Predicted by MELCOR for S.LOCA Base Case Sequence ... .. .... . ... .... . . 75 Figure 5.2.10 Core Support Plate Temperature Predicted by MELCOR for S-LOCA Base Case Sequence . ....... ............... ................ 76 Figure 5.2.11 Lower Head Inner Surface and Penetration Temperature Predicted by MELCOR for S.LOCA Base Case Sequence . . . . . . . . ............ ... . . . . 77 Figure 5.2.12 Primary System Pressure Predicted by MELCOR for S-LOCA Base Case S e q u e n ce . . . . . . . . . . . . . . . . . . . . . ........................... ........ 78 Figure 5.2.13 Water Volume in Cavity Predicted by MELCOR for S-LOCA Base Case Sequence ............................................ ............ 79 Figure 5.2.14 In-Vessel Hydrogen Production Predicted by MELCOR for S-LOCA Base Case Sequence . . . .............. .................... .. .. . . . 80 Figure 5.2.15 CCI Cavity Maximum Axial Penetration Predicted by MELCOR for S.LOCA Base Case Sequence .. ....................... . . . . . . . . . . . . 81 Figure 5.2.16 CCI Cavity Maximum Radial Penetration Predicted by MELCOR for S-LOCA Base Case Sequence .. ..... . . ..... .. .... . . . . . 82 Figure 5.2.17 Cavity Gases Production Predicted by MELCOR for S-LOCA Base Case Sequence ............ ......... . ............... .. ......... . . . . 83 Figure 5.2.18 Containment Pressure Predicted by MELCOR for S-LOCA Base Case Sequence .... ....... ...... ................... . . . . . . . . . . . . 84 ix

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1 LIST OF FIGURES (continued) l Figure 5.2.19 Containment Atmosphere ......... Temperature..... . . . .Predicted

. . . . . . . . . . . .by85 MELCOR for S-LOCA Base Case Sequence . . . . .

Gaseous Mole Fraction Distributed in Upper Compartment of Containment . . . . 86 Figure 5.2.20 Predicted by MELCOR for S-LOCA Base Case Sequence . . . . . . . . . . . . . . .

Figure 5.2.21 Gaseous Mole Fraction Distributed in Lower Compartm Figure 5.222 Gaseous Mole Fraction Distributed in Annular . . . . Compartment

. 88 o Predicted by MELCOR for S-LOCA Base Case Sequence . . . . . . . . . . . . . . .

Figure 5.2.23 Gaseous Mole Fraction Distributed in Cavity Predicted

............. . . 89 by MELCOR for S-LOCA Base Case Sequence . . . . . . . . . . . . . .

Gaseous Mole Fraction Distributed .... in IRWST Predicted

........... by. MI . . . &COR 90 for Figure 5.2.24 ... .

S-LOCA Base Case Sequence. . . . . . . . . . . . .

Vessel Collapsed Liquid Level Predicted by MELCOR ... for..... . . . . . 91 Figure 5.3.1 .. .... . ...

M-LOCA Base Case Sequence Figure 5.3.2 Primary System Pressure Predicted............. by MELCOR for M-LOCA

..... . . . . . . . . . 92 Base Case Sequence .. . .

SIT Liquid Volume Predicted by MELCOR for M.LOCA ............Base Case . . 93 Figure 5.3.3 ......... . . .. .........

Sequence ............

Core Ring 1 (node 110-115) Clad Temperature Predicted

.. . .... by . . . 94 Figure 5.3.4 .....

MELCOR for M-LOCA Base Case Sequence . . .

Core Ring 1 (node 104-109) Clad Temperature Predicted by . . . . . . . . . . . . 95 Figure 5.3.5 ....... ..

MELCOR for M-LOCA Base Case Sequence Core Ring 2 (node 210-215) Clad Temperature Predicted by. . . . . . . . . . 96 Figure 5.3.6 MELCOR for M-LOCA Base Case Sequence . . . . . . . . . . . . . . . . .

Core Ring 2 (node 204-209) Clad Temperature Predicted .. . . by . . . . . 97 Figure 5.3.7 ..

MELCOR for M-LOCA Base Case Sequence . . . . . . . . .

Core Ring 3 (node 310-315) Clad Temperature Predicted . 98 Figure 5.3.8 . .... ... . .. . by .......

MELCOR for M-LOCA Base Case Sequence Core Ring 3 (node 304-309) Clad Temperature Predicted by

....... .. .. . . . . . 99 Figure 5.3.9 ... .

MELCOR for M-LOCA Base Case Sequenu Figure 5.3.10 Core Ring 4 (node 410-415)....... Clad Temperature. . . . . . . . . . . .Predicted

. . . 100 by MELCOR for M-LOCA Base Case Sequence f

x

l LIST OF FIGURES (continued)

Figure 5.3.11 Core Ring 4 (node 404-409) Clad Temperature Predicted by MELCOR for M-LOCA Base Case Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 Figure 5.3.12 Core Support Plate Temperature Predicted by MELCOR for MELCOR Base Case Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . .... . . . . . . . 102 Figure 5.3.13 Lower Head Inner Surface and Penetration Temperatures Predicted by MELCOR Base Case Sequence . . . . . . . . . . . . . . . . . . . . .... . .. .. . .. 103 Figure 5.3.14 In-Vessel Hydrogen Production Predicted by MELCOR for M.LOCA Ba se Case S e q u e n ce . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 i Figure 5.3.15 Containment Pressure Predicted by MELCOR Base Case Sequence . . . . . . . . . . 105 Figure 5.3.16 Containment Atmosphere Temperature Predicted by MELCOR for M-LOCA Base Case Sequ e nce . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 Figure 5.3.17 Gaseous Mole Fraction Distributed in Upper Compartment of Containment Predicted by MELCOR for M.LOCA Base Case Sequence . . . . . . . . . . . . . . . . . . 10 7 Figure 5.3.18 Gaseous Mole Fraction Distributed in Lower Compartment of Containment Predicted by MELCOR for M-LOCA Base Case Sequence . . . . . . . . . . . . . . . . . . . 108 Figure 5.3.19 Gaseous Mole Fraction Distributed in Annular Compartment of Containment Predicted by MELCOR for M-LOCA Base Case Sequence . . . . . . . . . . . . . . . . . . 109 Figure 5.3.20 Gaseous Mole Fraction Distributed in Cavity Predicted by MELCOR for M-LOCA Base Case Sequence . . . .... .. . . . . . . . . . . . . . . . . . . . . 1 10 ,

I Figure 5.3.21 Gaseous Mole Fraction distributed in IRWST Predicted by MELCOR j for M-LOCA Base Case Sequence . .. . ... ..........................111  !

Figure 5.3.22 CC1 Cavity Maximum Axial Penetration Predicted by MELCOR q for M-LOCA Base Case Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 Figure 5.3.23 CCI Cavity Maximum Radial Penetration Predicted by MELCOR for M-LOCA Base Case Sequence . . . . ... ... . .... ... ........ . . . . 113 Figure 5.3.24 Cavity Gases Production Predicted by MELCOR for M-LOCA Base Case Sequence . . . . . . . . . . . . . . . ..... ....... . . . . . . . . . . . 114 Figure 5.4.1 Steam Generaters Pressure Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence ... .. ..... . . . . . . . . . . . . 1 15 Figure 5.4.2 Secondary Side Water Volume of the Broken Steam Generator Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence . . . . . . . . . . . . . . 116 xi

LIST OF FIGURES (continued)

Figure 5.4.3 Secondary Side Volume of the Unbroken Steam Generator Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence . . . . . . . . . . . . . . 117 Figure 5.4.4 Vessel Collapsed Liquid Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 Figure 5.4.5 Primary System Pressure Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 Figure 5.4.6 Core Ring 1 (node 110115) Clad Temperature Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence ...........................120 Figure 5.4.7 Core Ring 1 (node 104-109) Clad Temperature Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence ...........................121 ,

Figure 5.4.8 Core Ring 2 (node 210-215) Clad Temperature Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence ...........................122 ,

Figure 5.4.9 Core Ring 2 (node 204-209) Clad Temperature Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence . . . . . . . . . . . . . . . . . . . . . . . . 123 Figure 5.4.10 Core Ring 3 (node 310-315) Clad Temperature Predicted by MELCOR for ,

the 2-tubes SGTR (case 1) Base Case Sequence ...........................124 Figure 5.4.11 Core Ring 3 (node 304-309) Clad Temperature Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence ...........................125 Figure 5.4.12 Core Ring 4 (node 410-415) Clad Temperature Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence ...........................126 Figure 5.4.13 Core Ring 4 (node 404-409) Clad Temperature Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence ..........................127 Figure 5.4.14 Core Support Plate Temperature Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence ..............................128 Figure 5.4.15 lower Head Inner Surface and Penetration Temperature Predicted by c

MELCOR for the 2-tubes SGTR (cast 1) Base Case Sequence . . . . . . . . . . , . 129 Figure 5.4.16 In-Vessel Hydrogen Production Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence .................. . . . . . . . . . . . 130 Figure 5.4.17 Containment Pressure Predicted by MELCOR for the 2 tubes SGTR (case 1) Base Case Sequence ......... . . . . . . . . . . . . . . . . . . 131 l

!. Figure 5.4.18 Containment Atmosphere Temperature Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence ...... ... . . . . . . . . . . . . . . . . . . . 13 2 xii

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l f'

LIST OF FIGURES (continued)

' Figure 5.4.19 CCI Cavity Maximum Axial Penetration Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 Figure 5.4.20 CCI Cavity Maximum Radial Penetration Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence ..............................134 i Figure 5.4.21 Cavity Gases Production Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence ..............................135 Figure 5.4.22 Gaseous Mole Fraction Distributed in Upper Compartment of Containment Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence ......................................................... 136 ,

Figure 5.4.23 Gaseous Mole Fraction Distributed in Lower Compartment of Containment Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence .................-....................................... 137 Figure 5.4.24 Gaseous Mole Fraction Distributed in Annular Compartment of Containment '

Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence ..... .. ................................................138  ;

Figure 5.425 Gaseous Mole Fraction Distributed in Cavity Predicted by MELCOR for the ,

2-tubes SGTR (case 1) Base Case Sequence ..............................139 l Figure 5.426 Gaseous Mole Fraction Distributed in IRWST Predicted by MELCOR for the ,

2-tubes SGTR (case 1) Base Case Sequence .................... . . . . . . . . . 140 Figure 5.4.27 Radionuclides Released from Fuel Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence . . . . . ..... .........................141 Figure 5.4.28 Radionuclides Released to Main Steam Line House Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence . . . . . . . . . . . . . . . . . . . . . . . . . 142 Figure 5.4.29 Radionuclides Released to Environment Predicted by MELCOR for the 1 2-tubes STGR (case 1) Base Case Sequence ..............................143 Figure 5.430 Primary System Pressure Predicted by MELCOR for the 2-tubes SGTR I i

(case 2) Base Case Sequence . . . . . . . . . . . . . . . . . ........................144 Figure 5.431 Vessel Collapsed Liquid Level Predicted by MELCOR for the 2-tubes SGTR (case 2) Base Case Sequence . . . . . . . . . . . . . . . . . . . . . . . .. .. .... ... 145 Figure 5.432 Core Ring 1 (node 110-115) Clad Temperature Predicted by MELCOR for the 2-tubes SGTR (case 2) Base Case Sequence ..........................146 Figure 5.433 Core Ring 1 (node 104109) Clad Temperature Predicted by MELCOR for  !

the 2-tubes SGTR (case 2) Base Case Sequence ..........................147 xiii 1

- ~ ~ - - _ _

l l LIST OF FIGURES (continued) f

)

Figure 5.434 Core Ring 2 (node 210-215) Clad Temperature Predicted by MELCOR for. . . . .

f the 2 tubes SGTR (case 2) Base Case Sequence . . . .

i Core Ring 2 (node 204-209) Clad Temperature ..........

Predicted by MELCOR for. . . . .

Figure 5.435 the 2-tubes SGTR (case 2) Base Case Sequence Figure 5.436 Core Ring 3 (node 310-315) Clad Temperature Predicted by M the 2-tubes SGTR (case 2) Base Case Sequence Figure 5.437 Core Ring 3 (node 304-309) Clad Temperature

. . . . . . 151 Predicted by M the 2-tubes SGTR (case 2) Base Case Sequence Figure 5.438 Core Ring 4 (node 410-415) Clad Temperature Predicted by MELCOR for....

the 2-tubes SGTR (case 2) Base Case Sequence Figure 5.439 Core Ring 4 (node 404-409) Clad Temperature . .153 Predicted by M the 2. tubes SGTR (case 2) Base Case Sequence Figure 5.4.40 Core Support Plate Temperature....Predicted .... ..

by MELCOR for the

. .... .. . 154 2-tubes SGTR (case 2) Base Case Sequence . . . .

Lower Head Inner Surface and Penetration Temperatures ............ Predicted 155 by Figure 5.4.41 MELCOR for the 2-tubes SGTR (case 2) Base Case Sequence . . .

Figure 5.4.42 In-Vessel Hydrogen Production .......... ...... Predicted . . . . . . . . .by

. . . 15 MELCOR 6 for t (case 2) Base Case Sequence . . . . . . . . . .

Figure 5.4.43 Pool Volume in Cavity Predicted . ....... . by MELCOR for the 2-tubes SG (case 2) Base Case Sequence . . . . . . . .

Gascous Mole Fraction Distributed in Upper Compartment of Containment Figure 5.4.44 Predicted by MELCOR for the 2-tubes SGTR (case .....

2) Base Case. . . . . . . . . . . . . . . 15 Sequence ...................

Figure 5.4.45 Gaseous Mole Fraction Distributed in Annular Predicted by MELCOR for the 2-tubes SGTR (case 2) Base Case . . . . . . 159 Compartmen Sequence ......................

Gaseous Mole Fraction Distributed in Lower Compartment of Containment Figure 5.4.46 Predicted by MELCOR for the 2-tubes SGTR (case 2) Base .. ....Case 160 Sequence . ... .....

Gaseous Mole Fraction Distributed . . ..

in Cavity Pred cted by MELCOR for the.

Figure 5.4.47 2-tubes SGTR (case 2) Base Case Sequence Figure 5.4.48 Gaseous Mole Fraction Distributed in IRWST Predicted .

2. tubes SGTR (case 2) Base Case Sequence xiv

I LIST OF FIGURES (continued)

Figure 5.4.49 Containment Pressure Predicted by MELCOR for the 2-tubes SGTR (case 2) Base Case Sequence . . . . . . . . . . . . . . . . . . . . .......... . . . . . . . . . 163 Figure 5.4.50 Containment atmosphere Temperature Predicted by MELCOR for the 2-tubes SGTR (case 2) Base Case Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 Figure 5.4.51 CCI Cavity Maximum Axial Penetration Predicted by MELCOR for the

2. tubes SGTR (case 2) Base Case Sequence .................... . . . . . . . . . 165 Figure 5.4.52 CCI Cavity Maximum Radial Penetration Predicted by MELCOR for the 2-tubes SGTR (case 2) Base Case Sequence ..............................166 Figure 5.4.53 Cavity Gaseous Production Predicted by MELCOR for the 2-tubes SGTR (case 2) Base Case Sequence . . . . . . . . . . . . . . . . . ........................167 Figure 5.4.54 Radionuclides Released from Fuel Predicted by MELCOR for the 2-tubes SGTR (case 2) Base Case Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168 Figure 5.4.55 Radionuclides Released to Main Steam Line House Predicted by MELCOR for the 2-tubes SGTR (case 2) Base Case Sequence . . . .. ................169 ,

Figure 6.1.1 Water Volume in Cavity Predicted by MELCOR for SBO Dry Cavity,  !

Limestone Concrete Sequence . . . . . . . . . .. ..... ............ ... ..... 185 l 1

Figure 6.1.2 Water Volume in Cavity Predicted by MELCOR for SBO Wet Cavity, j Limestone Concrete Sequence . . . . . . . . . . . ............................186 i l

Figure 6.L3 CCI Cavity Maximum Axial Penetration Predicted by MELCOR for SBO Wet Cavity, Limestone Concrete Sequence .. .......................187 Figure 6.1.4 CCI Cavity Maximum Radial Penetration Predicted by MELCOR for SBO Wet Cavity, Limestone Concrete Sequence . . . . . . . . . . . . . . . . .......... 188 l

Figure 6.1.5 Cavity Gases Production Predicted by MELCOR for SBO Wet Cavity, Limestone Concrete Sequence .......... ........... ............. . . 189 l

Containment Pressure Predicted by MELCOR for SBO Wet Cavity,  ;

Figure 6.1.6 Limestone Concrete Sequence . . . . . . . . . . . . . . . . . ........ .............. 190 l l

Figure 6.1.7 Containment Atmosphere Temperature Predicted by MELCOR for SBO Wet Cavity, Limestone Concrete Sequence . . . . . . . . . . . . . . . ................. . 191 Figure 6.1.8 Gaseous Mole Fraction Distributed in Cavity Predicted by MELCOR for SBO Wet Cavity, Limestone Concrete Sequence ... . ......... . .. ... . 192 Figure 6.1.9 Gaseous Mole Fraction Distributed in Annular compartment of Containment Predicted by MELCOR for SBO Wet Cavity, Limestone Concrete Sequence . . . . . ... .... ...... ... ........ .... ... . . . . . . . . . 193 xv

l LIST OF FIGURES (continued)

Figure 6.1.10 Gaseous Mole Fraction Distributed in Lower Compartment of Containment Predicted by MELCOR for SBO Wet Caity, Limestone Concrete Sequence .......................................................... 194 Figure 6.1.11 Gaseous Mole Fraction Distributed in Upper Compartment of Containment Predicted by MELCOR for SBO Wet Cavity, Limestone Concrete S e q u e nce . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195 Figure 6.1.12 Gaseous Mole Fraction Distributed in IRS %T Predicted by MELCOR for SBO Wet Cavity, Limestone Concrete Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . 196 Figure 6.1.13 Radionuclide Environmental Releases Predicted by MELCOR for SBO Wet Cavity, Limestone Concrete Sequence .. . . . . . . . . . ... . . . . . . . . . . . . . . . . 197 Figure 6.1.14 Pool Volume in Cavity Predicted by MELCOR for M.LOCA Sequence with Basaltic Concrete and Dry Cavity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198 Figure 6.1.15 CCI Cavity Maximum Axial Pene-tration Predicted by MELCOR for M-LOCA Sequence with Basaltic Concrete and Dry Cavity . . . . . . . . . . . . . . . ... .... .199 Figure 6.1.16 CCI Cavity Maximum Radial Penetration Predicted by MELCOR for M.LOCA Sequence with Basaltic Concrete and Dry Cavity . . . . . . . . . . . . . . . . 200 Figure 6.1.17 Cavity Gases Production Predicted by MELCOR for M.LOCA Sequence with Basaltic Concrete and Dry Cavity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201 Figure 6.1.18 Containment Pressure Predicted by MELCOR for M-LOCA Sequence with Basaltic concrete and Dry Cavity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... .202 Figure 6.1.19 Containment Atmosphere Temperature Predicted by MELCOR for M-LOCA Sequence with Basaltic Concrete and Dry Cavity . . . . . . . . . . . . . . . . . . . . . . . . . . . 203 Figure 6.1.20 Pool Volume in Cavity Predicted by MELCOR for M.LOCA Sequence with Basaltic Concrete and Flooded Cavity . . . ..................... ...... 204 Figure 6.1.21 CCI Cavity Maximum Axial Penetration Predicted by MELCOR for M.LOCA Sequence with Basaltic Concrete and Flooded Cavity . . . . . . . . . . . . . . . . . . . . . 205 Figure 6.1.22 CCI Cavity Maximum Radial Penetration Predicted by MELCOR for M-LOCA Sequence with Basaltic Concrete and Flooded Cavity . . . . . . . . . . . . . . . 206 Figure 6.1.23 Cavity Gases Production Predicted by MELCOR for M.LOCA Sequence with Bastitic Concrete and Flooded Cavity .................. . . .. ... .. 207 Figure 6.1.24 Containment Pressure Predicted by MELCOR for M.LOCA Sequence with Basaltic Concrete and Flooded Cavity . . . . . . . . . . .... .............. . . . . 208 xvi

- . . - - - ~~ . . - , . .

, l LIST OF FIGURES (continued)

Figure 6.1.25 Containment Atmosphere Temperature Predicted'by MELCOR for M.LOCA Sequence with Basaltic Concrete and Flooded Cavity . . . . . . . . . . . . . . . . . . . . . . . . 209 l Figure 6.126 Pool Volume in Cavity Predicted by MELCOR for S-LOCA Sequence with Limestone Concrete and Dry Cavity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210 Figure 6.1.27 CCI Cavity Maximum Axial Penetration Predicted by MELCOR for S-LOCA Sequence with Limestone Concrete and Dry Cavity . . . . . . . . . . . . . . . . . . . . . . . . . 211 Figure 6.1.28 CCI Cavity Maximum Radial Penetration Predicted by MELCOR for S.LOCA Sequence with Limestone Concrete and Dry Cavity . . . . . . . . . . . . . . . . . . . . . . . . . 212 Figure 6.1.29 Cavity Oases Production Predicted by MELCOR For S.LOCA Sequence with Limestone Concrete and Dry Cavity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 s

Figure 6.130 Containment Pressure Predicted by MELCOR for S-LOCA Sequence with Limestone Concrete and Dry Cavity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214 Figure 6.131 Containment Atmospheric Temperature Predicted by MELCOR for S-LOCA Sequence with Limestone Concrete and Dry Cavity . . . . . . . . . . . . . . . . . . . . . . . . . 215 ,

Figure 6.2.1 Volume of Water in Cavity Predicted by MELCOR for SBO Wet Cavity, Basaltic Concrete Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216 Figure 6.2.2 CCI Cavity Maximum Axial Pcnetration Predicted by MELCOR for SBO Wet Cavity, Basaltic Concrete Sequence ..................................217 f

Figure 6.23 CCI Cavity Maximum Radial Penetration Predicted by MELCOR for SBO ,

Wet Cavity, Basaltic Concrete Sequence .................................218 .

Figure 6 2.4 Cavity Oases Production Predicted by MELCOR for SBO Wet Cavity, Basaltic Concrete Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219 Figure 6.2.5 Containment Atmosphere Temperature Predicted by MELCOR for SBO Wet Cavity, Basaltic Concrete Sequence .................................220 Figure 6.2.6 Containment Pressure Predicted by MELCOR for SBO Wet Cavity, Basaltic Concrete Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221 Figure 6.2.7 CCI Cavity Maximum Axial Penetration Predicted by MELCOR for S-LOCA Sequence with Basaltic Concrete and Dry Cavity . . . . . . . . . . . . . . . . . . . . . . . . 222 Figure 6.2.8 CCI Cavity Maximum Radial Penetration Predicted by MELCOR for i S.LOCA Sequence with Basaltic Concrete and Dry Cavity . . . . . . . . . . . . . . . . . . 223

]

1 Figure 6.2.9 Cavity Gases Production Predicted by MELCOR for S.LOCA Sequence with )

Basaltic Concrete and Dry Cavity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224 j I

xvii  !

l t

I LIST OF FIGURES (continued)

Figure 6.2.10 Containment Pressure Predicted by MELCOR for S.LOCA Sequence with Basaltic Concrcte and Dry Cavity ............................ . . . . . . . . 225 Figure 6.2.11 Containment Atmospheric Temperature Predicted by MELCOR for S.LOCA Sequence with Basaltic Concrete and Dry Cavity . . . . . . . . . . . . . . . . . . . . . . . . . . 226 Figure 6.3.1 Primary System Pressure Predicted by MELCOR for the 4. tubes SGTR Sequence with Limestone Concrete and Dry Cavity . . . . . . . . . . . . . . . . . . . . . . . . 227 Figure 6.3.2 Vessel Collapsed Liquid Level Predicted by MELCOR for the 4-tubes SGTR Sequence with Limestone Concrete and Dry Cavity . . . . . . . . . . . . . . . . . . 228 Figure 6.3.3 Core Support Plate Temperature Predicted by MELCOR for the 4-tubes SGTR Sequence with Limestone Concrete and Dry Cavity . . . . . . . . . . . . . . . . . . 229 Figure 6.3.4 Lower Head Inner Surface and Penetration Temperatures Predicted by MELCOR for the 4. tubes SGTR Sequence with Limestone Concrete a n d D ry Cavi ty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .... .............. . 230 Figure 6.3.5 In-Vessel Hydrogen Production Predicted by MELCOR for the 4-tubes SGTR Sequence with Limestone Concrete and Dry Cavity . . . . . . . . . . . . . . . . . . . . . 231 Figure 6.3.6 Primary System Pressure Predicted by MELCOR for the 25. tubes SGTR Sequence with Limestone Concrete and Dry Cavity . . . . . . . . . . . . . . . . . . . . . . 23 2 Figure 6.3.7 Vessel Collapsed Liquid Level Predicted by MELCOR for the 25-tubes SGTR Sequence with Limestone Concrete and Dry Cavity . . . . . . . . . . . . . . . . . . . . . . . . . 233 Figure 6.3.8 Core Support Plate Temperature Predicted by MELCOR for the 25-tubes SGTR Sequence with Limestone Concrete and Dry Cavity . . . . . . . . . . . . . . . . . . . 234 Figure 6.3.9 Lower Head Inner Surface and Penetration Temperatures Predicted

> by MELCOR for the 25-tubes SGTR Sequence with Limestone Concrete and Dry Cavity . . . .. ............... ......... .. ... . . . . . . . . . . 23 5 Figure 6.3.10 In. Vessel Hydrogen Production Predicted by MELCOR for the 25. tubes SGTR Sequence with Limestone Concrete and Dry Cavity . . . . . . . . . . . . . . . . . . . 23 6 l

Figure 6.3.11 Pool Volume in Cavity Predicted by MELCOR for the 2-tubes SGTR Sequence with Limestone Concrete and Dry Cavity . ... ... ....... . . . . . . . 237 Figure 6.3.12 Pool Volume in Cavity Predicted by MELCOR for the 4-tubes SGTR Sequence with Limestone Concrete and Dry Cavity . . . . ... . .......... .. 238 l Figure 6.3.13 Pool Volume in Cavity Predicted by MELCOR for the 25-tubes SGTR

! Sequence with Limestone Concrete and Dry Cavity ..... . . ... . . . . 239 l

i l

xviii l

I

I LIST OF FIGURES (continued)

Figure 6.3.14 CCI Cavity Maximum Axial Penetration Predicted by MELCOR for the 4-tubes SGTR Sequence with Limestone Concrete and Dry Cavity . . . . . . . . . . . . 240 Figure 6.3.15 CCI Cavity Maximum Radial Penetration Predicted by MELCOR for the 4-tubes SGTR Sequence with Limestone Concrete and Dry Cavity . . . . . . . . . . . . . 241 Figure 6.3.16 Cavity Gases Production Predicted by MELCOR for the 4-tubes SGTR Sequence with Limestone Concrete and Dry Cavity . . . . . . . . . . . . . . . . . . . . . . . . . 242 Figure 6.3.17 Containment Pressure Predicted by MELCOR for the 4-tubes SGTR Sequence with Limestone Concrete and Dry Cavity . . . . . . . . . . .... . . . . . . . . . 24 3 Figure 6.3.18 Containment Atmospheric Temperature Predicted by MELCOR for the 4-tubes SGTR Sequence with Limestone Concrete and Dry Cavity . . . . . . . . . . . . . 244 Figure 6.3.19 CCI Cavity Maximum Axial Penetration Predicted by MELCOR for the 25-tubes SGTR Sequence with Limestone Concrete and Dry Cavity . . . . . . . . . . . 24 5 Figure 6.3.20 CCI Cavity Maximum Radial Penetration Predicted by MELCOR for the 25-tubes SGTR Sequence with Limestone Concrete and Dry Cavity . . . . . . . . . . . . . 246 Figure 6.3.21 Cavity Gases Production Predicted by MELCOR for the 25-tubes SGTR Sequence with Limestone Concrete and Dry Cavity .. ... ...... . . . . . . . . . 24 7 Figure 6.3.22 Containment Pressure Predicted by MELCOR for the 25-tubes SGTR I Sequence with Limestone Concrete and Dry Cavity .... ..... . . . . . . . . . . . . 24 8 Figure 6.3.23 Containment Atmospheric Temperature Predicted by MELCOR for the

25. tubes SGTR Sequence with Limestone Concrete and Dry Cavity . . . . . . . . . . . 24 9 l

l l

XIX

l LIST OF TABLES i

CE System 80+ core Parameters . . . . . . . . . . . . . .

.. ....................14 Table 2.1 f . . . . . . . . . . . . . . . 15 CE System 80+ RCS Components Parameters . . . . . . . . . . . . .

Table 2.2 . . . . . . . . . . 17 CE System 80+ Safety Injection System Component Parameters . . . .

Table 23 Table 2.43 CE System 80 + IRWST Component Parameters . . . . . . . . . . . . . .

Core Initial Parameter Data Input for CE System 80+ MELCOR Model Table 4.1

. . . . . . . . . . 27 Flow Paths Data Input for CE System 80+ MELCOR Model . . . . . .

Table 4.2 Heat Structures Data Input for CE System 80+ MELCOR Model . . . . .

Table 43 ... ...... 33 Control Volumes Data Input for CE System 80+ MELCOR Model .

Table 4.4 Radionuclides Classes and initial Inventories ... ..

for CE System.. 80+ 34 MELCOR....

Table 4.5 ... .. . . ...... . ........

Model . . . . ...

Summary of MAAP and MELCOR Comparison for the SBO Base Case. . . . . . . . .

Table 5.1.1 ........................

Sequence ........

MELCOR Predicted Fractional Distribution

... .. ... ...of . . . 171 Radioactive Radio Table 5.1.2 ....

at 14,094 seconds of the SBO Base Case Sequence Table 5.13 MELCOR Predicted Fractional Distribution of Radioactive 580,000 seconds during Containment Melt-Through of the . . SBO

. . . 172Base Case Radio Sequence .

Table 5.2.1 Summary of MAAP and MELCOR Comparison for the S.LOCA Base.............

Can Seque nce . . . . . . . . . . . . . . . . . . . . . . .

Table 53.1 Summary of MAAP and MELCOR Comparison ..... ......

for

. . .the. . . .M.LOCA

. . . . 174 Base Case Sequence . ..

Summary of Major Events Predicted by MELCOR ... . . for .the . . 2....tube 175SGTR Table 5.4.1 (case 1), MSSV Functional and no Containment Spray . . .

Table 5.4.2 MELCOR Predicted Fractional ....... ....

Distribution of Radio

.............. ... 176 no Containment Spray . . . . . . . . . . . . .

Summary of MAAP and MELCOR Comparis<m for the 2-tubes SGTR

. . . . . 177 Table 5.43 Sequence (case 2) MSSVs Struck Open, and Containment Spray Availa Table 5.4.4 MELCOR Predicted Fractional Distribution of Radioactive 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br />. after Vessel Failure of the 2. tubes SGTR Sequence (case 178 2),

Rad MSSVs Struck Open, and Containment Spray Available n

--~- _

1 )

l l

LIST OF TABLES (continued)

Table 6.1.1 Effects of Flooded Casity for the SBO Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . 250  !

Table 6.1.2 Comparison of MAAP and MELCOR Predictions for the SBO Sequence with Flooded Cavity................................................... . . . . . . . 251 Table 6.1.3 MELCOR Predicted Fractional Distribution of Radioactive Radionuclides at 12,581 seconds of the SBO sequence with Limestone Concre:e and Wet Cavi ty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 2 Table 6.1.4 MELCOR Predicted Fractional Distribution of Radioactive Radionuclides at 511,525 seconds, after containment failure for the SBO Sequence with  ;

Limestone Concrete and Wet Cavity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253  :

Table 6.1.5 Effects of Flooded Cavity for M-LOCA Sequence with Basaltic Concrete Type....... ..... . .. ............ ................. . . . . . . . . 254 Table 6.1.6 Effects of Flooded Cavity for the S-LOCA Sequence with Basaltic Concrete Type.. ........................ .............................. .. 255 Table 6.2.1 Comparison of the Basaltic and Limestone Concrete . . . . . . . . . . . . . . . . . . . . . . . 25 6 Table 6.2.2. Effect of Cavity Concrete Type for the SBO Sequence with Flooded Cavity . . . . . . . 257 Table 6.23 MELCOR Predicted Fractional Distribution of. Jonuclides at 525,141 Seconds, after Vessel Failure of the SBO Sequence with Basaltic Concrete and Flooded Cavity ..... ......... ........ .... . . . . 258 Table 6.2.4 Effect of Cavity Concrete Types for the M-LOCA Sequence with Dry Cavity . . . . .. .. ........ ........... ............ ........ ... .259 Table 6.2.5 Effect of Cavity Concrete Types for the S.LOCA Sequence with Dry Ca vi ty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 60 Table 6.3.1 Effect of Rupture Size in the SGTR Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261 Table 7.1 Summary of Containment Failure Mode and Time for Base Cases . . . . . . . . . . . . . 265 Table 7.2 Summary of Containment Failure Mode and Time for Sensitivity Studies Involving Cavity Flooding .. ...................... ...... ... . . . . . 266 Table 7.3 Summary of Containment Failure Mode and Time for Sensitivity Studies Involving Concrete Type . .. ................... . . . ....... . . . . . 267 Table 7.4 Surnmary of Containment Failure Mode and Time for the SGTR Sequence . . . . . 268 xxi

l I

1. INTRODUCTION .

1.1 Background and Objectives This report describes an evaluation of potential severe accidents in the ABB Combustion Engineering System 80+ Nuclear Power Plant using the MELCOR computer code. The focus of the assessment is on the impact of core concrete interaction (CCl) on the containment's performance. The CCI may cause the containment to fail by over-pressurization from steam non-condensible gases, or the core debris may melt-through of the basemat. The assessment includes the following subtasks:

1. Several models were developed at BNL for a CE system 80+ MELCOR input deck, l namely, core, radionuclides, fuel dispersal interaction, direct containment heatmg,  ;

and in vessel heat structures about the core cells.

1

2. These models were combined with other models provided by the NRC and INEL to create a complete MELCOR input deck capable of analyzing severe accident sequences.

3. Potential accident sequences to be evaluated with MELCOR were reviewed and four were selected.

4. Complete MELCOR analyses of the selected accident sequences were made. For each sequence, it was assumed that (1) no mitigative features were operational, and, (2) the cavity flooders were not actuated. These parameters were designated as the base cases for each sequence.

5. Parametric studies using MELCOR were carried out. The study included the actuation of the cavity flooders and the containment spray system, and also considered various types of concrete in the reactor cavity (i.e., basaltic and limestone).

This report presents the results of these analyses. The accident sequences studied were a station blackout, a small break LOCA, a medium break LOCA, and a steam generator tube rupture.

1.2 MELCOR The MELCOR version 1.8.2 (or 1.8 NM) was used in the analysis. This version contains several new models, namely, the eutectic material reaction, a quench model for debris  !

falling in-vessel, radial relocation of molten debris, high and low molten-fuel ejection from l the reactor vessel, and direct heating of the containment. All these new models were actuated through user-specified parameters.  !

l The materialinteraction models during core melting include the eutectic reaction between l inconel grid spacers and zircaloy cladding, between intact zircaloy control-rod guide tubes i and steel control-rod cladding, and between absorber material and its__ cladding. The 1

I dissolution reaction includes the reaction between certain intact solid materials and molten eutectic mixtures (e.g., the dissolution of intact UO2 fuel by zircaloy bearing mixtures associated with the fuel cladding in the same core cell) are included in this analysis.

In the model for quenching the in-vessel falling debris, it is assumed that debris will relocate into the lower plenum when the core support plate in each radial ring fails, with a user-specified falling velocity. Furthermore, during the short interval when debris is falling, heat transfer from the falling debris to the water pool is calculated using a user-specified heat transfer coefficient. This quench model is used to simulate the energetic fuel-coolant interaction that may occur in the reactor pressure vessel.

The radial relocation of the molten debris model allows for radial spread of molten materials when they that are relocated downward by a candling motion, provided that there is a significant difference between the liquid levels in adjacent core rings.

There are two models of molten fuel ejection from the reactor pressure vessel which are  !

based on pressures at which the molten debris is ejected. The high pressure ejection model contains the interactions of hot debris with the containment's atmosphere, such as the oxidation of the metallic components of debris by both steam and oxygen, heat transfer from  !

the debris to the atmosphere, and surface deposition of the airborne debris by trapping or settling. This is referred as the direct containment heating model and is not applicable to l the low pressure injection case. The potential for a steam explosion and fuel coolant j interactions is not modeled in this MELCOR version.

l.3 Organization Section 2 briefly describes the overall ABB System 80+ plant, and some features of particular interest to the accident sequences being analyzed. The four accident sequences being simulated are summarized in Section 3. Section 4 describes the MELCOR input model for the System 80+ plant. The results of the MELCOR calculations, along with comparisons with the MAAP results are given in Section 5, for each accident sequence.

Section 6 gives the results of sensitivity studies, while Section 7 contains a brief summary and conclusions.

2

2. PLANT DESCRIPTION .

The descriptions of the System 80+ plant design are taken mostly from the Safety Analysis Report DC [1]. An overall description of the plant is given in the first part of this section.

The second and third parts describe systems important to the accident sequences being simulated.

2.1 Overall Plant Description The ABB Combustion Engineering System 80+ S+andard Plant is a 1300-MWe advanced pressurized water reactor. It is based on evolutionary improvements to the standard System 80 nuclear steam supply system (NSSS) and the Cherokee /Perkins balance of plant (BOP) design developed by Duke Power Co.

Simplicity in construction, operation, and maintenance is the main objective of this design.

The spherical steel containment provides 75% more space on the operating floor than a typical cylindrical containment of equal volume. There are several improved safety designs.

The four-train safety systems provide emergency core-cooling. The feedwater and decay-heat removal are dedicated to the active safety system. Emergency coolant is directed to the reactor vessel, and draws water from an inside containment-refueling water-storage tank (IRWST). A safety depressurization system which discharges into the IRWST in conjunction with the emergency core-cooling system, provides an alternative path for removing decay heat through feed-and-bleed. Figure 2.1 shows the overall plan of System 80 + .

2.2 Nuclear Steam Supply System (NSSS)

The NSSS contains two primary coolant loops (A and B), each of which has two reactor coolant pumps, a steam generator, a 42-inch inside diameter hot leg, and two 30-inch inside diameter cold legs. An electrically heated pressurizer is connected to loop A of the NSSS.

Pressurized water is circulated by single stage, centrifugal reactor coolant pumps driven by electric motors. The reactor coolant flows downward between the reactor vessel shell and the core support barrel, upward through the reactor core and the hot leg, to the tube side of the vertical U-tube ; team generators, and back to the reactor coolant plumps. The NSSS generates approximately 3931 MWt, and produces saturated steam in the steam generators.

The saturated steam is passed to the turbine and produces electric power at rate of 1300 MWe (net).

Figure 2.2 illustrates the configuration of the NSSS.

2.2.1 Core Design The reactor core is composed of 241 fuel assemblies, and 93 or more control element assemblies (CEAs). The fuel assemblies are arranged to approximately a right circular cylinder with an equivalent diameter of 3.65 meters and an active length of 3.81 meters.

The fuel assembly, which has 236 fuel rod positions (16 x 16 array), includes 5 guide tubes welded to spacer grids and it is closed at the top and bottom by end fittings.

3

l =

The guide tubes each displace four fuel rod positions and provide channels which guide the CEAs over their entire length of travel. In-core instrumentation is installed in the central guide tube of selected fuel assemblies. The in core instrumentation is routed into the bottom of the fuel assemblies through the bottom head of the reactor vessel.

The fuel is low-enrichment UO2 in the form of ceramic pellets and is encapsulated in helium- pressurized Zircaloy tubes which form a hematic enclosure.

2.2.2 Reactor Internal Structures The reactor's internal structures include the core-support barrel, the lower support structures, the in-core instrumentation nozzle assembly, the core shroud, and the upper-guide structure assembly. The core-support barrel is a right circular cylinder supported by a ring flange from a ledge on the reactor vessel, and carries the entire weight of the core. -

The lower support structure transmits the weight of the core to the core support barrel by means of a beam structure.

The core shroud surrounds the core and minimizes the amount of bypass flow. The upper guide structure provides a flow shroud for the CEAs, and limits upward motion of the fuel assemblies during pressure transients. There are lateral snubbers at the lower end of the core support barrel assembly.

Figure 2.3 shows the reactor's core and internal arrangement. Table 2.1 summarizes the important parameters of the core.

2.2.3 Reactor Coolant System (RCS)

The Reactor Coolant System (RCS)is arranged as two closed loops (A and B) connected in parallel to the reactor vessel. Each loop consists of one 42-inch inside diameter outlet hot leg, one steam generator, two 30-inch inside diameter cold legs, and two reactor coolant pumps. One pressurizer is connected to one of the loops via the surge line, i.e., loop A, of the RCS. The coolant flow paths in the RCS are illustrated in Figure 2.4.

The RCS operates at a nominal pressure of 2250 psia. Pressure is controlled by the pressurizer, where steam and water are maintained in thermal equilibrium. Steam is formed by an electrical immersion heater in the pressurizer, or is condensed by the pressurizer spray to limit variations in pressure caused by the contraction or expansion of the reactor coolant. The system is protected from overpressure by four spring-loaded safety valves connected to the top of the pressurizer. These valves discharge to the in-containment refueling water storage tank (IRWST), where the steam is released under water to be condensed and cooled. If the discharge of steam exceeds the capacity of the IRWST,it is vented to the containment's atmosphere.

Two steam generators produce steam for driving the plant's turbine-generator. Each steam generator is a vertical U-tube heat exchanger with an integral economizer which operates with the reactor coolant on the tube side, and with secondary coolant on the shell side.

Each unit is designed to transfer heat from the RCS to the secondary system to produce 4

saturated steam when there is the proper input feedwater. Moisture separators and steam driers on the shell side of the steam generator limit the moisture content of the steam during normal operation at full power. An integral flow restrictor was designed into the steam nozzle of each steam generator to restrict flow in the event of a break in the steam line.

Protection against overpressure for the secondary side of the steam generators is provided by spring-loaded safety valves located in the main steam system of the steam line isolation valves.

Other penetrations into the reactor coolant system are the four direct vessel-injection nozzles for the safety injection system; two return nozzles to the shutdown cooling systems, one in each hot leg; two pressurizer spray nozzles; vent and drain connections; and, sample and instrument connections.

Components and piping in the RCS are insulated with a material compatible with the temperatures involved to reduce heat losses and protect personnel from high temperatures.

The important thermal and hydraulic data are summarized in Table 2.2.

23 Engineered Safety Features The Engineered Safety features are designed to function in the event of an accidental release of radioactive fission products from the reactor coolant system. The features consist of the design of the containment structure, safety injection system, emergency feedwater system, safety depressurization system, and containment's spray system.

23.1 Design of the Containment Structure The containment vessel is a 200-foot diameter spherical shell with a wall approximately 1%

inches thick. The containment shell is supported by a spherical depression in an intermediate floor of the reactor building. The reactor building is a reinforced-concrete cylindrical building with a hemispherical dome. The exterior wall of the reactor building, including the dome, are referred to as the shield building. Space below the containment and inside the shield building is referred to as the subsphere and is occupied by Engineered Safety Features equipment.

The containment is designed to confine the release of radioactive material after an accident.

The radioactive material is ccafined by the containment isolation system. The containment also is designed to withstand the pressure and temperature of the DBA without exceeding the design leakage rate of 0.50% volume for the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

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23.2 Safety Injection System .

The safety injection system (SIS) provides core cooling during a loss-of-(LOCA), to maintain a coolable core-geometry and limit the claddin The SIS consists of active and passive injection subsystems. i d The active mechanically separated trains, each consisting ofh a safety h the directinjection (SI) pum valves. All the SI pumps draw water from the IRWST and discharge d during an it t roug vessel injection (DVI) nozzles into the reactor vessel when they are actuate accident.

The passive subsystem consists of four, i the identical p the RCS pressure drops below SIT's pressure (~ 610 psig). Table 23 summar zes design parameters of the safety injection system.

233 Safety Depressurization System (SDS)

The safety depressurization system consists of a reactos coolant d gas vent (R and a rapid depressurization (bleed process) system. The SDS provides a s means to vent non-condensible gases from the pressurizer and the reactor ves head to depressurize the RCS in the event that the pressurize spray system are unavailable.depressurize the RCS to initiate a prim base event of totalloss of feedwater.

Also, the SDS can depressurize the RCS in response to a severe acciden SDS is remote-controlled manually by the operators. The system is illustra 23.4 Containment Spray System (CSS)

The containment spray system (CSS) is designed to reduce fission containment p temperature from a main steam-line break i f or loss-o sends a spray of borated water to the containment's atmosphere hich take from the upper the containment. The flow is maintained by the containment's spray pumps f the w suction from the IRWST, through two heat exchangers, to the upper region o containment.

23.5 Emergency Feedwater System (EITVS)

The emergency feedwater system (EFWS) is designed to supply feeawater to th generators to remove heat The EFWS fromofthe consists twoRCS storageiftanks, mainfourfeedwater pumps, and system is a transient or accident. The associated piping and valves. Four pumps are motor-driven, and two are steam system can be automatically or manually initiated.

6

I 2.4 In-Containment Water Storage System The in-containment water storage system consists of the in-containment refueling water storage tank (IRWST), the holdup volume tank (HVT), the steam relief system (SRS), and the cavity flooding system (CFS). The system performs water collection, delivery, storage and heat sink functions inside the containment during normal operation and under accident conditions.

2.4.1 In-containment Refueling Water Storage Tank and Ifoldup Volume Tank The normal function of the IRWST is to store borated water, which can be used for refueling, SIS injection into the RCS, CSS injection, cavity flooding, and quenching of a SRS discharge. The IRWST water can be cooled by the CSS or SCS heat-exchangers during an accident.

When the containment sprays are actuated, the spray water drains into the HVT and is ultimately returned to the IRWST through the IRWST spillways.

2.4.2 Steam Relief System (SRS)

The steam relief system (SRS) controls pressure in the primary system during normal operation and accident conditions by transporting steam and water relieved through the pressurizer safety valves (PSVs) and rapid depressurization valves (RDVs) to the IRWST and dissipating its thermal energy.

2.4.3 Cavity Flooding System (CFS)

.The function of the cavity flooding system (CFS) is to flood the reactor cavity during a severe accident to cover core debris in the reactor cavity with water, which will cool and stabilize the molten debris.

The in-containment water storage system is illustrated in Figure 2.6, and the important parameters are summarized in Table 2.4.

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I Table 2.1 Core Parameters of the System 80+

241 Number of fuel assemblies in core, total B 93 Number of CEAs 56,876 Number of fuel-rod locations 0.208 Spacing between fuel assemblies, fuel rod surface to surface, 0.214 inches Spacing, outer fuel-rod surface to core shroud, inches 0.0393 Ilydraulic diameter, nominal channel, feet 60.9 Total flow area (excluding guide tubes), ft:

112.3 2

Total core area, ft 143.6 Core equivalent diameter, inches 152.46 Core circumscribed diameter, inches 3 102.7 x 10 Total fuel loading, kg U (assuming all rod locations are fuel rods) 257.1 x 10' Total fuel weight, lh UO (assuming all rod locations are fuel rods) 71,758 Total weight of Zircaloy,Ib 409.6 3

Fuel volume (including dishes), f t 16 x 16 Fuel Rad 0.506 Array Pitch, Inches 7.972 x 7.972 Outside dimensions Fuel rod to fuel rod, inches Fuel rod UO Fuel. rod material (sintered pellet) 0325 Pellet diameter, inches 0390 Pellet length, inches Zircaloy 4 Clad material 0332 Clad ID, inches 0382 Clad OD, (nominal), inches 0.025 Clad thickness, (nominal), inches 0.007 Diametral gap, (cold, nominal), inches 150 Active length, inches 7.918 l'lenum length, inches 14  !

l Il l Table 2.2 Components of the Reactor Coolant System of System 80+

Component Data Reactor Vessel Rated core thermal power, MWt 3,800 Design pressure, psia 2,500 Operating Pressure, psia- 2,250 Coolant outlet temperature, *F 615 Coolant' inlet temperature, *F 558 Total coolant flow,106 lb/h 165.6 3

Coolant volume (ft ) 5865 Steam Generators Number of units 2 Primary Side (or tube side)

Design pressure / temperature, psia /*F 2,500/650 Operating pressure, psia 2,250 Inlet temperature, *F 615 Outlet temperature, 'F 558 3

Coolant volume (ft ) 2973 Secondary Side (or shell side)

Design pressure / temperature, psia /*F 1,200/570 Full load steam pressure, temperature, psia /*F 1,000/545 Zero load steam pressure, psia 1,100 Total steam flow per gen., Ib/h 8.56 x 10 6 Full load steam quality, % (minimum) 99.75 Feedwater temperature, full power, F 450

' Pressurizer Design pressure, psia 2,500 Design temperature,'*F 700 '

Operating pressure, psia 2,500 Operating temperature, F 647 3 2,400 Internal volume (ft3)

Coolant volume (ft ) 1,200 Reactor Coolant Pumps Number of units 4 Type Vert.-Centrifugal Design capacity, (gpm) 111,400 Design pressure / temperature, psia /*F 2,500/650 Operatilig pressure, psia 2,250 3

Coolain volume (ft ) 134 15

Table 2.2 (continued)

Data Component

'L Reactor Coolant Piping  !

Flow per loop (20 lb/h) 82 Hot leg 41 Cold leg Pipe size (inside dia.), inches 42 Hot leg Cold leg 30 Suction leg 30 Discharge leg 2,500/650 Pipe design press./ temp., psia /*F Pipe operating press./ temp., psia /*F 2,250/615 Hot leg 2,250/558 Cold leg 3

Coolant volume (ft ) 135.6 each Hot leg 213.7 each Cold leg 70 Surge line 16

I Table 2.3 Parameters of the Components of the Safety Indection System Safety lidection Tanks Quantity 4 Safety Classification 2 Design Pressure, Internal / External 700 psig/100 psig Design Temperature 200*F Operating Temperature 120*F Normal Operating Pressure 610 psig Normal Liquid Volume 1858 ft3 Fluid Borated Water, 4400 ppm, max.

2000 ppm, min.

Safety Injection Pumps Quantity 4 Type Multistage, Horizontal, Centrifugal Design Pressure 2050 psig Maximum Operating Suction Pressure 100 psig Design Temperature 350*F Design Flow Rate 815 gpm*

• Does not include minimum bypass flow l

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f Table 2.4 Parameters of the Components of the In Containment Water Storage System l

In-containment Refueling Water Storage Tank 1

Quantity Cutmt. Design Pressure Design Pressure Cntmt. Atmospheric Normal Operating Pressure Catmt. Design Temp.

Design Temperature Catmt. Ambient Normal Operating Temperature Elevation 82 + 6 Normal Operating Level 545,800 gallons Normal Operating Water Volume 57,100 cu. ft.

Normal Operating Freeboard Volume Borated Water,4,000 - 4,400 ppm Fluid Holdup Volume Tank -. -

1 Quantity Cntmt. Design Pressure Design Pressure Cotmt. Ambient Normal Operating Pressure Cntmt. Ambient Minimum Operating Pressure Cntmt. Design Temp.

Design Temperature Containment Ambient Normal Operating Temperature Volume Empty Normal Operation 59,100 gallons before spillover to IRWST Accident Leakage water and containment spray Fluid w

18

-l

3. ACCIDENT SEQUENCES -

The accident sequences analyzed with the MELCOR code were those occurring with relatively high frequencies in the PRA [1]. These sequences were analyzed for information on the impact of a core-concrete interaction (CCI) on the containment's performance during an accident. The results were compared with the results obtained from the Modular Accident Analysis Program (MAAP) code, reported in Reference [1].

The following were the selected accident sequences:

1. Station Blackout (SBO)

2. Small-break loss of coolant accident (S LOCA)

3. Medium break loss of coolant accident (M-LOCA)

4. Steam Generator Tube Rupture (SGTR)

The basic assumptions and descriptions of the above sequences are given below:

Station Blackout Sequence (SBO)

A station blackout (SBO) sequence consists of a total loss of all AC and DC power, including the emergency diesel generators, the alternate combustion turbine / generator, and the station batteries.

The cavity flooding system was assumed not to be operational; only the passive injection subsystem from four pressurized safety injection tanks (SIT) was assumed to be available.

The active safety injection subsystems, i.e., HPSI, LPSI, and charging pumps were not available.

The primary system was assumed depressurized by the pressurizer safety valves (PSV). The contaimnent spray system (CSS) and the emergency feedwater system (EFWS) were assumed non-operable at the time of the accident.

Small break Loss-of Coolant Accident (S-LOCA) 2 2 This sequence consists of a small break in the cold leg with an area of 0.0032 M (0.034 ft ),

The equivalent diameter is 0.0635 m (2.5 inches). The accident is coupled with the failure of both containment sprays and the active safety-injection subsystem (i.e., HPI, LPI, and charging pumps). The passive safety injection subsystem is available to directly discharge borated water into the reactor vessel when pressure in the primary system falls below 4.21x106 Pa (610 psig).

The cavity flooding system is assumed non-operational, and the emergency feedwater system is unavailable to supply water to the secondary side of the steam generators.

19

---~

'f Medium Break Loss-of Coolant Accident (M LOCA) h i This sequence is similar to the small break loss-of-coolant acciden i l nt area is 0.0127 of the break in the cold leg is 0.127 m (5.0 inches) in diameter; the equ va e 2

m2 (0.1364 ft ),

Steam Generator Tube Rupture (SGTR) Sequence The rupture of tubes in one of 2

d to bethefunctional steam but the generat were considered for this sequence; in one, the MSSV was assumeV was assumed to be containment sprayswere unavailable. In the other case, ij tion, the mainMSS open and the containment sprays were operational. The active safety n d to be unavailable and auxiliary feedwater system, and cavity flooding system were assume for both cases. These analyses hi ct Sensitivity analyses were carried out for each SGTR scenario, the of the a

(

t ays and the of type of concrete in the cavity (i.e. limestone vs ba rupture of more tubes in the steam generator.

M 20

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4. MELCOR INPUT Parts of the MELCOR input deck for the CE System 80+ plant were prepared by INEL and BNL The inputs required for the RCS, steam generator, and containment were provided by INEL, while those required fer the core, radionuclides, fuel-dispersal interaction, direct containment heating, and in-vessel heat structures about the core cells were prepared at BNL.

BNL incorporated the two parts of the input deck to form a complete input deck in which the System 80+ plant is represented by 44 control volumes, 58 flow paths,115 heat structures, and 60 core-cells. The plant nodalization is illustrated in Figure 4.1, and summarized in Tables 4.1-4.3.

4.1 Core Nodalization The System 80+ core is divided into four radial rings and fifteen axial levels in each of the radial rings. The nodalization is illustrated in Figure 4.2. The first three axial levels represent the lower plenum. Level 3 represents the core support plate. Levels 4 through 15 are in the core region. The active fuel region (AF) is represented by axial levels 5 to 14, while levels 4 and 15 represent the non fueled core elements at the bottom and top of the active fuel cell, respectively.

The height of the activt fuel region is divided equally to represent the 10 axial levels (Levels 5 through 14). The height of axial level 3 is the thickness of the core-support plate.

The heights of levels 1 and 2 are the height of the lower plenum between the core-support plate and the bottom of the lower plenum.

The distributions of materials (i.e., UO 2, Zircaloy, Inconel and Stainless Steel) in each of the radial rings in the core and lower plenum region are summarized in Table 4.4. Figure 4.3 illustrates the locations of the control element assembly and the division of the radial rings. .

4.2 Reactor Coolant System (RCS)

The reactor coolant system (RCS) consists of the reactor vessel, the primary cooling loops, the primary and secondary steam generator systems, and the pressurizer. The reactor pressure vessel is represented by 6 control volumes: the annular downcomer, the lower plenum, the core channel, the core bypass, the upper plenum, and the reactor vessel dome.

There are two circulation loops (loop A and B), each consisting of 5 control volumes: the hot leg,2 RCP suction legs, and 2 RCP cold legs. The circulation loops are connected to steam generators. Each steam generator is divided into two sections: primary side (tube side), and secondary side (shell side). The primary side contains 2 control volumes: the rising tube section and the down tube section. The secondary side is divided into 4 control volumes: downcomer, economizer, evaporator, and the boiler and separator. The pressurizer, the feedwater inlet, the steam line outlet, and the main steam line house (or 21

I the turbine room) also are modeled as separate control volumes. There are 36 flow paths and 61 heat structures in the RCS nodalization.

4.3 Containment and Engineered Safety Feature The spherical containment of the System 80+ is divided into 5 control volumes: the lower compartment, the annular compartment, the upper compartment, the in-containment refueling water storage tank, and the cavity.

The bottom of the cavity is located about 5.8 meters below the reactor's lower head. The cavity floor is 4.5 m (15 feet) thick.' A section of the containment shell is imbedded about 1 meter below the surface of the concrete floor. Its presence in the concrete cannot be included in the corium/ concrete interaction model in the MELCOR code. However, the erosion of the concrete floor to a depth of 1 meter (where the containment shell is located) is reported for all MELCOR calculations. MELCOR's default compositions of limestone and basaltic concrete were used, adding a steel mass fraction of 0.135 to represent the rebar in the concrete.

The engineered safety features modeled in the MELCOR analyses include the cavity  !

flooding system, which discharges water to the cavity from the IRWST, the pressurizer i safety valves, which release primary system pressure to the IRWST, the passive injection subsystem, which injects borated water from SIT into the direct injection nozzle at the I reactor vessel, and the steam-generator safety valves.

The containment spray was modeled only in the sensitivity studies for the SGTR accident sequences in which the main steam safety valve was stuck open, and a flooded cavity assumed.  ;

l .

Eleven control volumes,14 flow paths, and 25 heat structures are modeled for the containment and engineered safety systems.

4.4 Radionuclides Model The 15 default radionuclide classes in the MELCOR RN package were used for the analyses. The formation of Csl was added as Class 16. Table 4.5 summarizes these classes of fission product material and the initial mass inventory of each class.

i The original CORSOR model, which simulates the release of the fission products from the l

core fuel, was used for all MELCOR calculations with the default values of aerosol diameter and distribution.

The decay heat power during the accident was calculated by using the ANS Standard, correcting for the fission power from U-235, U-238, and Pu-239.

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Figure 4.3 MELCOR Radial and CE Location Input Model for CE System 80+ Core and Lower Plenum 25

t ELCOR Model

'lable 4.1 Control Volumes Data hiput for CE System 80+ M VOID NAME EtrIHALPY C-2-POOL VOLLIQ DEMSITY M FRICTION TLIQ TVAP MASS Ma*3 FJG/Ma

• 3 J/KG VO111ME PRESSURE K K 133 0.000E+00 1.0448E+00 1.9720E+06 1.9844E+01 1.0000E+00 ALoter NtRiB PA 1.0100E+05 322.0000 322.0000 3.9940E+04 0.000E+00 1.0779E+00 4.0518E+06 3.3091E+00 1.0000E+00 BCOMPT 10 20 1.01GOE+05 322.0000 322.0000 2.0236E+04 2.994E+02 5.8132E+02 2.0564E+05 -5.0000E-01 3.3812E+004.1220E-01 1.0000E+00BCOMPT DCOMPr 322.0000 373.0885 2.9613E+05 0.000E+00 1.0779E+00 4.0518E+06 25 1.0100E+05 322.0000 322.0000 4.1511E+04 2.066E+03 5.5512E+02 2.0788E+05 -2.6976E-01 4.3894E-01 FCOMPT-RWST 1.0056E+01 0.0000E+00 WJrl.EGA 30 1.0100E+05 322.0000 322.0019 2.0445E+06 1.619E+01 6.8051E+02 1.4494E+06 2.0560E+01 0.0000E+00 S"IGENAPRIMARY1 40 1.0100E+05 592.4999 592.4999 1.1017E+04 2.498E+01 7.2230E+02 1.3461E+06 2.0560E+01 0.0000E+00 S7CENAPRIMARY2 100 1.4860E+07 574.7000 574.7000 1.8041E+04 2.498E+01 7.52168+02 1.2649E+06 8.2581E+00 0.0000E+00 PUMPSUCTIONA1 110 1.4680E+07 559.5001 559.5001 1.8787E+04 7.53368+02 1.2617E+06 115 1.4530E+07 558.9000 2.5464E+03 3.380E+00 1.1119E+05 1. 8139 E + 01 9.9474E-01 SIT-1 558.9000 5.262E+01 5.1748E+01 8.4623E+00 0.0000E+00 COLDLEGA1 120 1.4590E+07 310.8000 310.8002 5.1748E+05 6.477E+00 7.3564E+02 1.3139E+06 129 4.3161E+06 568.9001 4.7648E+03 8.2581E+00 0.0000E+00 PUMPSUCTIONA2 130 1.5410E+07 568.9001 3.380E+00 7.5336E+02 1.2617E+06 8.4623E+00 0.0000E+00 CDLDLEGA2 558.9000 558.9000 2.5464E+03 6.477E+00 7.5466E+02 1.2614E+06 2.1386E+01 0.0000E+00 FEEDWATERA 140 1.4590E+07 558.9001 558.9001 4.8879E+03 7.6621E+02 1.1936E+06 150 1.5410E+07 544.99?8 7.6621E+02 1.000E+00 6.2643E+02 1.1383E+06 2.1000E+01 2.1809E-01 STGENADOWNCOMEH 160 6.5998E+06 544.9998 2.136E+01 1.2194E+06 1.3910E+01 0.0000E+00 S7CENAEVAPORATE 530.0001 555.1098 1.7113E+04 1.335E+01 7.5711E+02 1.3910E+01 0.0000E+00 STGENAECONOMIZE 170 6.6000E+06 549.9999 549.9999 1.0104E+04 1.410E+01 7.9641E+02 1.1040E+06 172 6.6500E+06 526.9999 1.1231E+04 1.1331E*06 2.1000E+01 6.1696E-01 S7UENABOILER 174 6.6499E+06 526.9999 1.035E+02 3.3579E+02 3.1000E+00 9.9879E-01 STEAMLINEA 510.0000 555.1082 9.0698E+04 6.881E-02 3.5093E+01 2.7366E+06 1.0056E+01 0.0000E+00 Ht7tLEGB 180 6.6000E+06 550.0000 555.1102 1.9875E+03 1.619E+01 6.8051E+02 1.4494E+C6 190 6.6000E+06 592.4999 1.1017E+04 7.2694E+02 1.3340E+06 2.0360E+01 0.0000E+00 S10ENBPRIMARY1 200 1.4860E+07 592.4999 1.8157E+04 2.498E*01 1.2633E+06 2.0560E+01 0.0000E+00 S7UENBPRIMARY2 y 572.4999 572.4999 2.498E+01 7.5271E+02 8.2581E+00 0.0000E+00 PUMPSUCT10tml

& 210 1.4680E+07 559.2000 559.2000 1.8800E+04 3.380E+00 7.5409E+02 1.2597E+06 215 1.4530E*07 558.4999 2.5488E+03 5.1748E+01 1.1119E+05 1.8139E+01 9.9474E-01 SIT 2 220 1.4590E+07 558.4999 5.262E+01 1.2598E+04 8.4623E+00 0.0000E+00 COLDIEGB1 310.8000 310.8002 5.1748E+05 6.477E+00 7.5522E+02 8.2581E+00 0.0000E*00 FUMPSucrIONB2 229 4.3161E+06 558.5999 4.8915E+03 7.5409E+02 1.2597E+06 230 1.5420E+07 558.5999 558.4999 2.5488E+03 3.380Ee00 1.2598E+06 8.4623E+00 0.0000E+00 CDLDIEGB2 240 1.9590E+07 558.4999 6.477E+00 7.5522E+02 2.1386E+01 0.0000E+00 FEEDWATERB 558.5999 558.5999 4.8915E+03 1.000E+00 8.2975E+02 9.9482E+05 2.1000E+01 2.18098-01 S1UENBDOWNCOMER 250 1.5420E+07 504.0000 504.0000 8.2975E+02 6.2752E+02 1.1333E+06 1,3910E+01 1.0000E-06 S7CENBEVAPORATE 260 6.5200E+06 1.7142E+04 2.136E+01 27 0 6.5300E+06 529.0001 554.3975 1.335E+01 7.4756E+02 1.2452E+06 1.3910E+01 0.0000E+00 S7UENBECONOMIZE 554.8990 554.8990 9.9770E+03 1.410E+01 7.9633E+02 1.1040E+06 2.1000E+01 6.1696E-01 S7UENBBOILER 272 6.5794E*06 526.9999 526.9999 1.1230E+04 1.035E+02 3.3389E+02 1.1458E+06 274 6.5799E+06 513.0000 554.3956 9.0184E+04 6.881E 02 3.5091E+01 2.7367E+06 3.1000E+00 9.9879E-01 STEAMLINEB 280 6.5300E+06 550.7001 555.1102 1.9874E+03 5.262E+01 5.1748E+01 1.1119E+05 1.8139E+01 9.9474E-01 SIT-3 29 0 6.6000E+05 310.8000 310.8002 5.1748E+05 0.000E+00 1.2773E+00 1.7913E+07 -5.0000E+00 1.0000E+00 'IU-BIDG 329 4.3161E+06 305.4000 1.2773E+10 0.000E+00 1.1639E+00 4.2236E4061.8139E+01 -7.2488E+00 1.0000E+00 330 1.0136E+05 305.4000 300.0000 300.0000 1.1639E+10 5.262E+01 5.1748E+01 1.1119E+05 1.1639E+01 0.0000E+00 9.9474E-01 SIT-4ENVIRONME7fr 800 1.0130E+05 310.8000 310.8002 5.1748E+05 3.277E+01 7.5448E+02 1.2609E+06 2.5203E+00 0.0000E+00 DOWNCOMER 129 4.3161E+06 558.8000 558.8000 2.4723E+04 1.797E+01 7.5585E+02 1.2568E+06 7.2670E+00 0.0000E+00 LOWERPLEtm CORE 500 1.5180E+07 557.9999 557.9999 1.3584E+04 3.256E+01 6.8749E+02 1.4338E+06 7.2670E+00 0.0000E+00 CDREBYPASS 510 1.5130E+07 589.9999 589.9999 2.23872+04 6.814E+00 6.8092E+02 1.4491E+06 8.6511E+00 0.0000E*00 UPPERPLEl m 520 1.5020E+07 592.4999 592.4999 4.6396E+03 1.291E+01 6.8216E+02 1.4461E+06 1.4114E+01 0.0000E+00 UPPERHEAD 530 1.5000E+07 591.9999 591.9999 8.8073E+03 5.575E+01 7.4147E+02 1.2961E+06 540 1.4970E+07 565.5000 565.5000 4.1337E+04 3.459E+01 3.5861E+02 1.7090E+06 1.7000E+01 5.0009E 01 PRESSURIZER 550 1.4930E+07 610.3999 614.1162 2.4814E+04 600 1.4760E+07

b i

Table 4.2 Flow Paths Data Input for CE System 80+ MELCOR Model LEfCIH AREA FRJCr OPEN MFIEW VELLIQ FIEW VOWME JUFCTION ELEVATION IM**2) KG/S M/S PA7N m 'IU m (M) TD (M) (M) I')

1.9844E+01 1.9844E*01 1.0000E+01 3.3950E+02 1.0000E+00 0.00000E+00 0.0000E+00 ACOMPT BCO Wr 15 10 20 VALVE O 00000E+00 0.0000E+00 Cottr- FAIL 16 10 400 5.3381E+01 . 3381E+01 1.0000E+00 1.0000E-01 AmtWF DCOWT 3.9352E+01 1.0000E*01 7.1900E+02 1.0000E+00 0.00000E+00 0.0000E+00 25 10 30 3.9352E+01 6.7280E+01 1.0000E+00 0.00000E+00 0.0000E+00 TUNNEL 26 25 20 3.3091E+00 3.3091E+00 1.5500E+01 8.0526E+00 1.6180E+01 6.9000E400 1.0000E+00 0.00000E+00 0.0000E+00 BYPASS 27 25 20 8.0526E+00 9.2900E+00 1.0000E+00 0.00000E+00 0.0000E+00 BCOMPI-DCOMPT 35 20 30 1.0581E+01 1.0581E+01 1.0000E+01

-4.3000E+00 -4.3000E+00 2.0000E+00 2.0270E-01 1.0000E+00 0.00000E+00 0.0000E+00 CAVITY SPILL 40 40 25 1.3940E+01 1.0000E+00 0.00000E+00 0.0000E+00 ECOMPT OVERPRESS 45 40 20 3.3091E*00 3.3091E+00 5.0000E-01 0.0000E*00 20 40 3.3091E+00 3.3091E+00 5.0000E 01 1.3940E+01 1.0000E*00 0.00000E+00 ECDMFr VACUUM 46 1.0000E+00 1.02492E+04 1.6810E+01 VESSEL-lorLEGA 95 540 100 0.0831E+00 8.0831E+00 5.5817E+00 8.9380E-01 8.0813E+00 1.9629E+01 9.1820E+00 2.2950E+00 1.0000E+00 1.02452E+04 6.5600E+00 HurLEGA-SGA 105 100 110 9.3190E+00 2.2950E+00 1.0000E+00 1.02445E*04 6.1800E+00 SGA 110 110 115 1.9629E+01 1.9629E+01 1.0000E+00 5.10955E+03 2.9600E+00 SGA-PUMPINA1 115 115 120 1.9629E+01 5.4230E+00 1.0661E+01 2.2950E+00 5.4230E+00 8.0813E*00 6.6480E+00 4.5610E-01 1.0000E+00 5.11287E+03 1.4800Et01 PMPINAl -C214A1 125 120 130 VALVE 0.00000E+00 0.00COE+00 SIT-DOWNCOMER 129 129 500 8.0710E+00 8.0710E+00 2.0700E+01 1.0000E-01 7.7007E+00 7.7003E+00 1.0000E-02 1.2700E-02 1.0000E+00 0.00000E+00 0.0000E+00 PIPE-BREAK 11L1 130 20 3.7075E+00 4.5610E-01 1.0000E+00 4.98257E+03 1.4850E+01 COGEIEAl -VESSEL 135 130 500 0.0813E+00 7.3156E+00 1.0000E+00 5.10955E+03 SGA-PUMPINA2 145 115 140 1.9629E+01 5.4230E+00 1.0661E+01 2.2950E+00 2.9600E+00 5.4230E+00 8.0813E+00 6.6480E+00 4,5610E-01 1.0000E+00 5.10944E+03 1.4870l+01 PMP1NA2 -Cw1EA2 155 140 150 4.5610E-C1 1.0000E+00 5.11135E+03 1.4850E+01 COWEIEA2 -VESSEL 165 150 500 8.0813E,00 7.3156E+00 3.7075E+00 2.1300E+01 2.1300E+01 5.0000E-01 1.6908E-02 0.0000E+00 0.00000E*00 0.0000E+00 SGBDOWNCOMER 169 160 170 4.f484E+00 5.7665E+00 1.0000E+00 0.00000E+00 0.0000E+00 SGBDO1R-ECON 175 170 172 1.2165E+01 1.2165E+01 1.0000E+00 SGCCMR-EVAP 176 170 174 1.2165E+01 1.2165E+01 4.6484E+00 5.7665E+00 0.00000E+00 0.0000E+00 177 172 180 1.3910E+01 1.3910E+01 1.1393E+01 4.3070E+00 1.0000E+00 0.00000E+00 0.0000E+00 SGAECON-BOIL 178 174 180 1.3910S+01 1.3910E+01 1.1393E+01 4.3070E+00 1.0000E+00 0.00000E+00 0.0000E+00 SGAEVAP-BOIL 179 180 170 2.2060E+01 2.2060E+01 5.0000E-01 8.9029E+00 1.0000E+00 0.00000E+00 0.0000E+00 SGASEP-DNO1R 2.8310E+01 2.8310E+01 5.4884E+01 7.9450E-01 0.0000E+00 0.00000E+00 0.0000E+00 SGABOIL-S7L 185 180 190 1.0000E+00 1.02309E+04 1.6780E+01 VESSEL-tKMEGB 195 540 200 8.0831E+00 8.0831E+00 5.5817E+00 8.9380E-01 205 200 210 8.0813E+00 1.9629E+01 9.1820E+00 2.2950E+00 1.0000E+00 1.02140E+04 6.5400E+00 HGrLEGB-SGB 210 210 215 1.9629E+01 1.9629E+01 9.3190E+00 2.2950E+00 1.0000E+00 1.02435E+04 6.1400E+00 SGB ha 1.9629E+01 5.4230E+00 1.0661E+01 2.2950E+00 1.0000E+00 5.13059E+03 2.9700E+00 SGB-PUMPINBL-215 215 220 1.0000E+00 5.12817E+03 1.4910E*01 PMPINB1-C WIEB1 225 220 230 5.4230E+00 8.0813E+00 6.6480E+00 4.5610E-01 229 229 500 8.0710E+00 8.0710E+00 2.0700E+01 1.0000E-01 VALVE 0.00000E+00 0.0000E*00 SIT-DOWNCCHER 235 230 500 0.0313E+00 7.3156E+00 3.7075E*00 4.5610E-01 1.0000E+00 5.12549E+03 1.4880E+01 COLDEIEB1 -VESSEL 245 215 240 1.9629E+01 5.4230E+00 1.0661E+01 2.2950E+00 1.0000E+00 5.13059E*03 2.9700E+00 SGB-PUMPINB2 255 240 250 5.e230E+00 8.0813E+00 6.6480E+00 4.5610E-01 1.0000E+00 5.12817E+03 1.4910E+01 PMPINB2 -CWIEB2 265 250 500 8.0813E+00 7.3156E+00 3.7075E+00 4.5610E-01 1.0000E+00 5.12549E+03 1.4880E+01 COTEIEB2 -VESSEL 269 260 270 2.1300E+01 2.1300E+01 5.0000E-01 1.6908E-02 0.0000E+00 0.00000E+00 0.0000E+00 SGBDOWNCOMER 275 270 272 1.2165E+01 1.2165E+01 4.6484E+00 5.7665E+00 1.0000E+00 0.00000E+00 0.0000E+00 SGBDO1R-ECON 276 270 274 1.2165E+01 1.2165E+01 4.6484E+00 5.7665E+00 1.0000E+00 0.00000E+00 0.0000E+00 SGBDOTR- EVAP 277 212 280 1.3910E,01 1.3910E+01 1.1393E+01 4.3070E+00 1.0000E+00 0.00000E+00 0.0000E*00 SGBECON-BOIL 278 274 280 1.3910E+01 1.3910E+01 1.1393E+01 4.3070E+00 1.0000E+00 0.00000E+00 0.0000E+00 SGBEVAP-BOIL 279 280 270 2.2060E+01 2.2060E+01 5.0000E-01 8.9029E+00 1.0000E+00 0.00000E+00 0.0000E+00 SGBSEP-DNO*!R 285 280 290 2.8310E+01 2.8310E+01 - 84E+01 7.9450E-01 0.0000E+00 0.00000E+00 0.0000E+00 SGBBOIL S*L 305 600 100 8.8067E+00 8.8067E+00 E+01 5.2000E-02 1.0000E+00 0.00000E+00 0.0000E+00 PRZR-HJrLEGA 315 600 40 2.3460E+01 -1.0700E+00 . 01 1.1100E-02 VALVE 0.00000E+00 0.0000E+00 SRV 325 180 330 2.8310E+01 2.8310E+01 5.SouoE+01 1.0320E-01 VALVE 0.00000E+00 0.0000E*00 SGA-SRV 329 329 500 8.0710E+00 8.0710E+00 2.0700E+01 1.0000E-01 VALVE 0.00000E+00 0.0000E+00 SIT-DOWNCO1ER 335 280 330 2.8310E+01 2.8310E+01 5.5000E*01 1.0320E-01 VALVE 0.00000E*00 0.0000E*00 SGB-SRV 429 429 500 8.0710E+00 8.0710E*00 2.0700E+01 1.0000E-01 VAINE 0.00000E+00 0.0000E+00 SIT-DOWNCCHER 505 500 510 1.7832E+00 1.7832E+00 6.2877E+00 2.9525E+00 1.0000E+00 2.04716E+04 9.1900E+00 DWNCMR- 10WERHEAD 515 510 520 2.5203E+00 2.5203E+00 3.5052E+00 5.6485E*00 1.0000E+00 2.04933E+04 4.8000E+00 LOWERIEAD -CORE 525 520 530 2.5203E+00 2.5203E+00 3.5052E+00 1.8049E+00 1.0000E+00 4.35538E+03 3.5100E+00 LOWERIEAD- BYPASS 535 520 540 7.2670E+00 7.2670E+00 3.4918E+00 5.6485E+00 1.0000E+00 1.60768E+04 4.1400E+00 CORE -UPPEP.PIEM 545 530 540 7.2670E+00 7.2670E+00 3.4918E+00 1.8049E+00 1.0000E+00 4.36292E+03 3.5500E+00 BYPASS UPPERPIJN 555 550 540 8.6511E+00 8.6511E+00 4.8236E+00 1.3856E+00 1.0000E+00 2.05415E+01 2.0000E-02 CEA HOUSItG 565 500 550 1.1E33E*01 1.1639E*01 5.0000E-01 4.3870E-03 0.0000E+00 0.00000E+00 0.0000E+00 DOWNCOMR tidHEAD 900 510 25 1.6910E-01 0.0000E+00 1.6910E-01 1.0000E-02 VALVE 0.00000E*00 0.0000E+00 VESSEL BRI%CH

m .-

Table 4.3 Ileat Structures for CE System 80+ MELCOR Model HEAT STRUCIURE OF SYSTEM 80+

. -+----.----- ---- ---.----------- ------------------- ----+----~~-------------------- Surface (lef----------

t/Right) -------- Rad

---

t l Heat Structure - l --- -- Bcmndary ---- ation - l

---

.----------.-----.-----fAltit.

ifNi.znber Name Nod Geo -----------fNult-.

Orien

+--+----.-+---..------------+---+----+--------+-----+---

- fS Vol CcmdfFlowf- Area------ f Chr.L------f---DZ----fEmissRadNodf

--+-+---+----+----+---------+---------+--~~-----+-~0.0 --- ---

~---+-------+

No Rad 5 RECT 0.1691 Horz 1.0 N O ----

1 10011 RV IONER HEAD 510 1 Itfr 2.22 4.36 0.1691 0.0 No Rad 1.0 N 0.5 1 135.0130 4.6292 10.45 0.0 No Rad 2 10021 10WER RV WALL 5 CYIJi 1.1731 Vert --- 0.0 No Rad 0 --- ---

1.0 N 0.5 1 32.6079 2.5671 4.0291 0.0 No Rad 3 19081 UGS-CYLIt0ER 5 CY12t 8.6511 Vert 2.5671 4.0291 0.0 No Rad 0.5 1 33.9085 8.6511 Hors 1.0 N 0.5 1 8.2728 3.9878 0.762 0.0 No Rad j 4 10083 USG-BOT-PLATE 5 RECT 3.9878 0.762 0.0 No Rad 0.5 1 8.2728 14.2230 2.5761 0.0762 0.0 No Rad 5 10085 USG '[OP-PIATE 5 RECT 12.6802 Nors 1.0 N 0.5 0.5 1

1 14.2230 2.5761 0.0762 0.0 No Rad 3 CYIAI 7.3828 vert .97.0 N 0.5 1 .3530 0.0886 1.2683 0.0 No Rad 6 10091 CEA-1UBR-UPP 0.5 1 .3921 0.0886 1.2683 0.0 No Rad 3 CYTR 8.6511 Vert 97.0 N 0.5 1 1.5205 0.0886 5.45 0.0 No Rad 7 10092 G A-1UBE-D N E 0.5 1 1.6887 0.0886 5.45 0.0 No Rad 3 RECT 8.6511 Vert 1.0 N 0.5 1 205.9593 4.0291 4.0291 0.0 No Rad 8 10111 GA WEBS-PLA11t 0.5 1 205.9593 4.0291 4.0291 0.0 No Rad 10 CY128 11.6387 Vert 1.0 N 0.5 1 3.1043 4.4450 0.2223 0.0 . No Rad 9 10121 UPPER RV FIANGE 0 --- --- --- 0.0 No Rad 5 HSUP 11.861 Horz 1.0 N 0.5 1 1.0 4.5054 2.2527 0.0 No Rad 10 10131 UPPER HEAD 0 --- --- ---

0.0 No Rad 5 RECT 19.8812 Vert 1. N 10 1 EXT 3287. 12- 12. 0.0 No Rad 11 01002 MALIJtD 0 --- --- ---

0.0 No Rad 5 RECT 20.8812 Horz 1., N 10 1 EXT 475. 21. 21. 0.0 No Rad p 12 01003 DECKAB 0 --- --- ---

0.0 No Rad oo 1. N 10 1 EXT 5279.5 72. 72. 0.0 No Rad 13 01004 BQPTA 2 RECT 25.3812 Hors --- 0.0 No Rad 0 --- ---

14 02001 DECKBA 5 RECT 19.3812 Horz 1. N 20 1 EXT 475. 21. 21. 0.0 No Rad 0 --- --- ---

0.0 No Rad 15 02002 MM.rmn 3 RECT 3.3091 Vert 1. N 20 1 EXT 1456. 16.5 16.5 0.0 No Rad 0 --- --- ---

0.0 No Rad 16 02003 MALIB 3 RECT 3.3091 Vert 1. N 20 1 EXT 18366. 16.5 16.5 0.0 No Rad 0 --- --- ---

0.0 No Rad 17 02004 FICOR 9 RECT 4.0812 Horz 1. N 20 1 EXT 901. 30. 30- 0.0 No Rad

( 0 --- --- ---

0.0 No Rad 18 02005 EQPIB 2 RECT 11.3812 Hors 1. N 20 1 EXT 1393. 37. 37. 0.0 No Rad 0 --- --- --- 0.0 No Rad 19 03002 MALIDA 5 RECT 19.8812 Vert 1. N 30 1 EXT 3287. 12. 12. 0.0 No Rad 0 --- --- ---

0.0 No Rad l

20 03003 MkLLDB 3 RECT 3.3812 Vert 1. N 30 1 EXT 1456. 16.5 16.5 0.0 No Rad j 0 --- --- ---

0.0 No Rad 21 04001 IRMST WALLS 20 CYIR -4.57 Vert 1.0 N 0.5 1 490.33 6.069 6.069 0.0 No Rad i

0 --- --- ~~-

0.0 No Rad l

22 04011 IRWST F100R 20 RECT -4.5744 Hort 1.0 N O --- --- ---

0.0 No Rad l

0.5 1 129.88 0.9545 0.9545 0.0 No Rad t

23 04021 IRWST CEILING 20 RECT 3.3091 Horz 1.0 N 0.5 1 795.33 0.9545 0.9545 0.0 No Rad 0.5 1 795.33 0.9545 0.9545 0.0. No Rad ~

24 00101 FIOW-SKIRT 5 CYIR 1.17310 Vert 1.0 N 510 -1 Itfr 7.09870 3.7592 0.6011 0.0 No Rad 510 -1 EXT 7.23710 3.7592 0.6011 0.0 No Rad 25 00102 BARREL-2 5 CYIR 1.77420 Vert 1.0 N 510 -1 Itfr 8.07430 3.9878 0.64450 0.0 No Rad 500 -1 EXT 8.38290 3.9878 0.64450 0.0 No Rad 26 00103 BARPEL-3 5 CY128 2.41870 Vert 1.0 N 510 -1 Ilfr 1.27280 3.9878 0.10160 0.0' No Rad 500 -1 EXT 1.27230 3.9878 0.10160 0.0 No Rad 27 00104 BARREL-4 5 CYI28 2.52030 Vert 1.0 N 530 -1 Iffr 59.466.7 3.9878 4.74670 0.0 No Rad 28 00105 BARREL-5 5 CYIR 7.2670 Vert 1.0 N 540 -1 Itfr 52.98110 3.9878 1.3841 0.0 No Rad 500 -1 EXT 55.0742C 3.9878 1.3841 0.0 No Rad i

- _ _ _ . _ _ _ . _ _ = _ _ -

Table 4.3 (continued)

HEAT STRUCIU4E CF SYS E M 80+

---

.----------t------------------------------------ -t l Heat Structure l Bcnndary Surface (Lef t/Right) l

- Rad ation -

-.----..---------------------fAltit.----...fOrienfMult----fSfVolfCandfFlowf-Area------f-Chr.L------f---DZ----

ifNumber Name

,-.+-....-+.----.....

Nod Geo

---

.-+---+.---+------ .+-----+------+-+---+----+----+---------+---------+---------+-----.+-------+

f EmisJ Rad Ndf 29 00004 BAFFM-4 5 CYIN 2.52030 Vert 1.0 N 520 -1 ItE 1.56740 3.91610 0.12740 0.0 No Rad 530 -1 EXT 1.58520 3.91610 0.12740 0.0 No Rad 30 00005 BAFFM-5 5 CYIN 2.64770 Vert 1.0 N 520 -1 IrF 4.68750 3.91610 0.38100 0.0 No Rad 530 -1 EXT 4.74060 3.91610 0.38100 0.0 No Rad 31 00006 BAFFLE-6 5 CYIR 3.02870 Vert 1.0 N 520 -1 Iffr 4.68750 3.91610 0.38100 0.0 No Rad 530 -1 EXT 4.74060 3.91610 0.38100 0.0 No Rad 32 00007 RAFFLE-7 5 CYIN 3.40970 Vert 1.0 N 520 -1 Itfr 4.68750 3.91610 0.38100 0.0 No Rad 530 -1 EXT 4.74060 3.91610 0.38100 0.0 No Rad 13 00008 BAFrm-8 5 CYLN 3.79070 Vert 1.0 N 520 -1 Irrr 4.68750 3.91610 0.38100 0.0 No Rad 530 -1 EXT 4.74060 3.91610 0.38100 0.0 No Rad 34 00009 BAFFM-9 5 CYIR 4.17170 Vert 1.0 N 520 -1 Iffr 4.68750 3.91610 0.38100 0.0 No Rad 530 -1 EXT 4.74060 3.91610 0.38100 0.0 No Rad 35 00010 BAFFM-10 5 CYIR 4.55270 Vert 1.0 N 520 -1 Irrr 4.68750 3.91610 0.38100 0.0 No Rad 530 -1 EXT 4.74060 3.91610 0.38100 0.0 No Rad 36 00011 BAFFM-11 5 CYIN 4.93370 Vert 1.0 N 520 -1 Itfr 4.68750 3.91610 0.38100 0.0 No Rad 530 -1 RXT 4.74060 3.91610 0.38100 0.0 No Rad 37 00012 BAFFLS-12 5 CY1R 5.31470 Vert 1.0 N 520 -1 Itrr 4,68750 3.91610 0.38100 0.0 No Rad 530 -1 EXT 4.74060 3.91610 0.38100 0.0 No Rad 38 00013 BAFFM-13 5 CYIR 5.69570 Vert 1.0 N 520 -1 Iffr 4.68750 3.91610 0.38100 0.0 No Rad 530 -1 EXT 4.74060 3.91610 0.38100 0.0 No Rad 39 00014 BAFFM-14 5 CYIN 6.07670 Vert 1.0 N 520 -1 Ittr 4.68750 3.91610 0.38100 0.0 No Rad 530 -1 EXT 4.74060 3.91610 0.38100 0.0 No Rad tJ 40 00015 BAFFM-15 5 CYIR 6.45770 Vert 1.0 N 520 -1 INT 9.9569 3.91610 0.80930 0.0 No Rad y:2 530 -1 EXT 10.0658 3.91610 0.80930 0.0 No Rad 41 00050 CORE-FAP 5 RECT 7.2670 Horz 0.9709 N 520 -1 Iffr 15.9835 3.98780 0.1158 0.0 No Rad 540 -1 EXT 15.9835 3.98780 0.1158 0.0 No Rad 42 00051 BYPASS-FAP 5 RECT 7.2670 Horz 0.0291 N 530 -1 Irrr 15.9835 3.98780 0.1158 0.0 No Rad 540 -1 EXT 15.9835 3.98780 0.1158 0.0 No Rad 13 91001 SIT 1-CYLINDER 5 CYIN 8.0 Vert 1.0 N 129 1 INT 1.0 2.59 12.5 0.0 No Rad 0 --- --- --- 0,0 No Rad L4 92001 SIT 2-CYLINDER 5 CYIR 8.0 Vert 1.0 N 229 1 INT 1.0 2.59 12.5 0.0 No Rad 0 --- --- ---

0.0 No Rad 5 93001 SIT 3-CYLINDER S CYIN 8.0 Vert 1.0 N 329 1 Irrr 1.0 2.59 12.5 0.0 No Rad 0 --- --- ---

0.0 No Rad 46 94001 SIT 4-CYLINDER S CYIR 8.0 Vert 1.0 N 429 1 Iffr 1.0 2.59 12.5 0.0 No Rad 0 --- --- ---

0.0 No Rad 47 90002 CV160-FIDOR 3 RECT 20.0 Horz 1.0 N 160 -1 Itfr 1.0 .1 0.11600 0.0 No Rad 160 -1 EXT 1.0 .1 0.11600 0.0 No Rad 48 90003 CV260-F100R 3 RECT 20.0 Hort 1.0 N 260 -1 Iffr 1.0 .1 0.1160C O.0 No Rad 260 -1 EXT 1.0 .1 0.11600 0.0 No Rad 49 90006 CV190-F100R 3 RECT 7.0 Horz 1.0 N 190 -1 Iffr 1.0 .1 0.11600 0.0 No Rad 190 -1 EXT 1.0 .1 0.11600 0.0 No Rad 50 90007 CV290-FICOR 3 RECT 7.0 Horz 1.0 N 290 -1 Itfr 1.0 .1 0.11600 0.0 No Rad 290 -1 EXT 1.0 1 0.11600 0.0 No Rad 51 90009 PR2-CYLINDER 5 CYIR 11.0 Vert 1.0 N 600 1 Iffr 1.0 2.4383 12.0 0.0 No Rad 0 --- --- ---

0.0 No Rad 52 90009 CV400 F100R 3 RECT -6.0 Horz 1.0 N 400 -1 INT 100.0 1.0 1.0 0.0 No Rad 400 -1 EXT 100.0 1.0 1.0 0.0 No Rad 53 90010 CV040-FIDOR 3 RECT 1.0 Hors 1.0 N 040 -1 Iffr 10.0 1.0 1.0 0.0 No Rad 040 -1 EXT 10.0 1.0 1.0 0.0 No Rad 54 02510 CAVITY-FLOOR 5 RECT -5.7585 Horz 1.0 N O --- --- ---

0.0 No Rad 025 -1 EXT 107.80 0.85 0.9144 0.0 No Rad 55 02520 CAVITY-WALL-BOT 5 CY1N -4.5744 Vert 1.0 N 025 -1 Irrr 104.92 7.366 7.88 0.0 No Rad 040 -1 EXT 161.67 7.366 7.88 0.0 No Rad 56 02530 CAVITY-WALL-TOP 5 CY1R 3.3091 Vert 1.0 N 025 -1 Itfr 99.63 7.366 8.6 0.0 No Rad 020 -1 EXT 153.51 7.366 8.6 0.0 No Rad

l l

Table 4.3 (continued)

HEAT STRLX3URE OF SYSTEM 80+

-.f Bmndary Surface Reft /Right) -- Radiation -+

-.f....--.---.---.-------......-----------------------------.-----.-------------------

Heat Structure 9-.--t- ------t-

_ . . - . , - - - - - - - - . . . - - . d l Geo l Al t i t . [Or ---t------+lSlVo1lCondl ienl Mult -----+l Area - -Chr.L Flow l-+---+----+----+---

- - -- - - l+ - - - DZ

- - - - - +l Emi na l Rad Mod l

+--- .s lNo 0.0 No Rad 1TNtanberl

+--+...-..+. .---

Namn

..----- .-+ ..+-- -+--------+- --.+------+-+---+----+----+

6 CYIN 7.43747 Horz 1.0 N 0.5 1 14.363

-- - --+----

2.9464 - --+---------+------

2.9464

--- 0.0 No Rad 57 30011 107 133 A PIPING 0 0.381 0.0 No Rad 1.0 N 0.5 1 8.873 0.762 0.0 No Rad 58 30012 XOVER-Al PIPING 6 CYIN 4.94752 Hors 0 --- ---

0.0 No Rad 1.0 N 0.5 1 8.873 0.762 0.381 0.0 No Rad 59 30013 XOVER- A2 PIPIN3 6 CYIN ti.94752 Hors 0 --- ---

0.381 0.0 No Rad 1.0 N 0.5 1 14.082 0.762 0.0 No Rad 60 30014 CDIDLEG-Al 6 CYIN 7.59501 Hort 0 --- ---

0.381 0.0 No Rad 1.0 N 0.5 1 14.082 0.762 0.0 No Rad 61 30015 ODIDIEG-B1 6 CYIN 7.59902 Hors 0 --- ---

2.9464 0.0 No Rad O N 0.5 1 14.363 2.9464 0.0 No Rad 6 CYIN 7. 4 Y147 Hor:. 0 --- --- --

0.0 No Rad 62 30021 iOT IEG B PIPING 8.873 0.762 0.381 6 CYIN 4.94752 Hors 1.0 N 6.5 1 --- --- 0.0 No Rad 63 30022 L*WER-B1 PIPING 0 ---

0.0 No Rad 1.0 N 0.5 1 8.873 0.762 0.381 0.0 No Rad 64 30023 IOVER-B2 PIPING 6 CYIN 4.94752 Horz 0 --- ---

0.381 0.0 No Rad 1.0 N 0.5 1 14.082 0.762 0.0 No Rad 65 30024 ODIDIEG-B1 6 CYIN 7.59902 Horz 0 -- ---

0.381 0.0 No Rad 1.0 N 0.5 1 14.082 0.762 0.0 No Rad 16 30025 CDIDIEG-B2 K CYIN 7.59902 Hors 0 --- --- ---

0.0 No Rad 1.0 .0169 1.55 3 CYIN 10.81 Vert 12113. N 0.5 -1 1.0 .0169 1.55 0.0 No Rad 57 18001 FIEAN'!VBE 172-1A 0.5 -1 1.0 .0169 1.55 0.0 No Rad 3 CYIN 12.36 Vert 12113. N 0.5 -1 1.0 .0169 1.55 0.0 No Rad 58 18002 FI1W41UBE 172-2A 0.5 -1 1.0 .0169 1.575 0.0 No Rad

$ i9 18003 FI1 TAM 7UBE 180-01 3 CYIN 13.91 vert 12113. N 0.5 0.5

-1

-1

-1 1.0 1.0

.0169

.0169 1.575 1.575 0.0 No Rad 0.0 No Rad 3 CYIN 15.485 Vert 12113. N O.5 1.0 .0169 1.575 0.0 No Rad

'O 18004 FrEF4 'IUBE 180-U2 0.5 -1 1.0 .0169 1.575 0.0 No Rad 17.06 Vert 12113. N 0.5 -1 0.0 No Rad 18005 FrEAM '1VBE 180-U3 3 CYIN -1 1.0 .0169 1.575

'1 0.5 1.0 .0169 1.575 0.0 No Rad

-1 0.0 No Rad 18006 FrEAM 'IUBE 180-U4 3 CYIN 18.635 Vert 12113. N 0.5 -1 1.0 .0169 1.575

'2 0.5 1.0 .0169 1.55 0.0 No Rad

-1 13 18011 STRAM 4TBE 174-1A 3 CYIN 10.81 Vert 12113. N 0.5 1.0 .0169 1.55 0.0 No Rad 0.5 -1 1.0 0169 1.55 0.0 No Rad 74 18012 FrEAM TUBE 174-2A 3 CYIN 12.36 Vert 12113. N 0.5 -1 1.0 .0169 1.55 0.0 No Rad 0.5 -1 1.0 .0169 1.575 0.0 No Rad 75 18013 dM TUBE 180-D1 3 CYIN 13.91 Vert 12113. N 0.5 -1

-1 1.0 0169 1.575 0.0 No Rad 0.5 1.0 .0169 1.575 0.0 No Rad 3 CYIN 15.485 Vert 12113. N 0.5 -1 1.0 0169 1.575 0.0 No Rad 76 18014 STEAM 7UBE 180-D2 0.5 -1

.0169 1.575 0.0 No Rad 1.0 77 18015 FI11AM 'IUBE 180-D3 3 CYIN 17.06 Vert 12113. N O.5 -1

-1 1.0 .0169 1.575 0.0 No Rad 0.5

-1 1.0 0169 1.575 0.0 No Rad 78 18016 STitAM TUBE 180-D4 3 CYIN 18.635 Vert 12113. N 0.5 -1 1.0 0169 1.575 0.0 No Rad 0.5 1 IMP 1.0 4.5166 3.0 0.0 No Rad 5 CYIN 10.81 Vert 0.5 N 172 1.0 4.5166 3.0 0.0 No Rad 79 18021 SGA SHROUD-1 170 1 EXT 0.0 No Rad 1 INY 1.0 4.5166 3.0 5 CYIN 10.81 Vert 0.5 N 174 1 EXT 1.0 4.5166 3.0 0.0 No Rad 80 18022 %A SHROUD-2 170 4.516 3.0 0.0 No Rad 10.81 Vert 1.0 N 172 1 INT 14.0 0.0 No Rad 81 18023 SEPARTOR-PL 5 RECT 174 1 EXT 14.0 4.516 3.0 1 INT 1.0 4.5166 8.5064 0.0 No Rad 5 CYIN 13.91 Vert 1.0 N 180 1 EXT 1.0 4.5166 8.5064 0.0 No Rad 82 18024 92A SHROUD-3 170 5.5245 1.3356 0.0 No Rad 1 INT 1.0 5 CY1M 22.4164 Vert 1.0 N 180 1 EXT 1.0 5.5245 1.3356 0.0 No Rad 83 18025 SGA RHROUD-4 170 4.8087 8.2744 0.0 No Rad 1 INT 1.0 5 CYIN 10.81 Vert 1.0 N 170 --- .-- 0.0 No Rad 84 16010 SGA DC-SHELL-1 0 ---

Table 4.3 (continued)

HEAT STRUCTURE OF SYSTEM 80+

l Heat Structure Bmndary Surface (Lef t/Right)

---+----+--------t-----+---- -t-t---+----t----+---------+---------t---- ---*t-- Radiatican +

il t------t-----------------+l Number l Name Nod l Geol Altit, lOrienl Nult lSlVo1lCcmdl Flow l Area l Chr.L l DZ l Eksiss

+..+--.-..+-.....---.------+.--+----+.------.+-----+------+-+---+---.+....+-------..+--...----+----..---+-.----+lRadModl 85 18031 SGA DC-SHELL-2

---

+

5 CYIN 19.0844 Vert 1.0 N 170 1 INT 1.0 5.8928 4.6676 0.0 No Rad 0 --- ... --

0.0 No Rad 86 18032 SGA DC-SHELL-3 5 CYIR 23.752 Vert 1.0 N 180 1 INT 1.0 5.8928 1.6062 0.0 No Rad 0 --- --- --

0.0 No Rad 87 18033 SGA DONE 5 HSUP 25.3582 Vert 1.0 N 180 1' INT 1.0 5.9056 2.9528 0.0 No Rad 0 --- -.- ---

0.0 No Rad 88 18034 SEPARA*IORS 3 CYIN 23.8727 Vert 194.0 N 180 1 INF 1.0 0.2286 1.3399 0.0 No Rad 180 1 EXT 1.0 0.2286 1.3399 0.0 No Rad 89 18035 DRYER 3 RECT 25.5 Vert 1.0 N 180 1 INT 11.24 5.89 0.1495 0.0 No Rad 180 1 EXT 11.24 5.89 'O.1495 0.0 No Rad 90 28001 SIEAM 'IUBE 272-1B 3 CYIN 10.81 Vert 12113. N 0.5 -1 1.0 .0169 1.55 0.0 No Rad 0.5 -1 1.0 .0169 1.55 0.0 No Rad 91 28002 STEAM 'IUBE 272-2B 3 CY1M 12.16 Vert 12113. N 0.5 -1 1.0 .0169 1.55 0.0 No Rad 0.5 -1 1.0 .0169 1.55 0.0 No Rad 92 28003 STEAM'IUBE 280-U1 3 CYIN 13.91- Vert 12113. N 0.5 -1 1.0 .0169 1.575 0.0 No Rad 0.5 -1 1.0 .00169 1.575 0.0 No Rad 93 28004 S11AM'IVBE 280-U2 3 CYIN 15.485 Vert 12113. N 0.5 -1 1.0 .0169 1.575 0.0 No Rad 0.5 -1 1.0 .0169 1.575 0.0 No Rad 94 28005 STEAM 'IUBE 280-U3 3 CYIN 17.06 Vert 12113. N 0.5 -1 1.0 .0169 1.575 0.0 No Rad 0.5 -1 1.0 .0169 1.575 0.0 No Rad 95 28006 STEAM 7UBE 280-U4 3 CYIN 18.635 Vert 12113. N 0.5 -1 1.0 .0169 1.575 0.0 No Rad 0.5 -1 1.0 .0169 1.575 0.0 No Rad 96 28011 WEAM'IUBE 274-1B 3 CYIN 10.81 Vert 12113. N 0.5 -1 1.0 .0169 1.55 0.0 No Rad 0.5 -1 1.0 .0169 1.55 0.0 No Rad W 97 28012 STRAM 'IUBE 274-2B 3 CYIN 12.36 Vert 12113. N O.5 -1 1.0 .0169 1.55 0.0 No Rad

" 0.5 -1 1.0 .0169 1.55 0.0 No Rad 98 28013 STEAM *IUBE 280-D1 3 CYIR 13.91 Vert 12113. N 0.5 -1 1.0 .0169 1.575 0.0 No Rad 0.5 -1 1.0 .0169 1.575 0.0 No Rad 99 28014 STEAM 7UBE 280-D2 3 CYIN 15.485 Vert 12113. N 0.5 -1 1.0 .0169 1.575 0.0 No Rad 0.5 -1 1.0 .0169 1.575 0.0. No Rad

.00 28015 STEAM 'IUBE 280-D3 3 CYIN 17.06 Vert 12113. N 0.5 -1 1.0 .0169 1.575 0.0 No Rad 0.5 -1 1.0 .0169 .1.575 0.0 No Rad

.01 28016 STEAM'IUBE 280-D4 3 CYIN 18.635 Vert 12113. N O.5 -1 1.0 .0169 1.575 0.0 No Rad 0.5 -1 1.0 .0169 1.575 0.0 No Rad 102 28021 SGB SHROLD-1 5 CYIN 10.81 Vert 0.5 N 272 1 INT 1.0 4.5166 3.0 0.0 No Rad 270 1 EXT 1.0 4.5166 3.0 0.0 No Rad 103 28022 SGB SHROUD-2 5 CYIN 10.81 Vert 0.5 N 274 1 INr 1.0 4.5166 3.0 0.0 No Rad 270 1 EXT 1.0 4.5166 3.0 0.0 No Rad 104 28023 SEPARIOR-PL 5 RECT 10.81 Vert 1.0 N 272 1 INT 14.0 4.516 3.0 0.0 No Rad 274 1 EXT 14.0 4.516 3.0 0.0 No Rad 105 28024 SGB SHROLD-3 5 CYIR 13.91 Vert 1.0 N 280 1 INF 1.0 4.5166 8.5064 0.0 No Rad 270 1- EXT 1.0 4.5166 8.5064 0.0 No Rad 106 28025 SGB SHROIE-4 -5 CYIN 22.4164 Vert 1.0 N 280 1 INT 1.0 5.5245 1.3356 0.0 No Rad

, 270 1 EXT 1.0 5.5245 1.3356 0.0 No Rad

107 28030 SGB DC-SHELL-1 5 CYIR 10.81 Vert 1.0 N 270 1 INF 1.0 4.8087 8.2744 0.0'No Rad 0 --- --- -.-

0.0 No Rad l 108 20031 SGB DC-SHELL-2 5 CYIR 19.0844 Vert 1.0 N 270 1- INT 1.0 5.8928 4.6676 0.0 No Rad

( 0 .- - --- ---

0.0 No Rad 109 28032 SGB DC-SHELL-3 5 CYIR 23.752 Vert 1.0 N 280 1 INT 1.0 5.8928 1.6062 0.0 No Rad l 0 -- .-- ... 0,0 No Rad

110 28033 SGB DCHE 5 HSUP 25.3582 Vert 1.0 N 280 1 INT 1.0 -5.9056 2.9528 0.0 No Rad i 0 --. --- --.

0.0 No Rad i 111 28034 SEPARATORS 3 CYIN 23.8727 Vert 194.0 N 280 1 INT 1.0 0.2286 -1.3399 0.0 No Rad 280 1 EXT 1.0 0.2286 1.3399 0.0 No Rad 112 28035 DRYER 3 RECT 25.5 Vert 1.0 N 280' 1 INT 11.24 5.99 0.1495 0.0 No Rad 280 1 EXT 11.24 5.89- 0.1495 0.0 No Rad l

l l

Table 4.3 (continued)

HEAT STPUCIURE OF SYSTEM 80+

Bcamdary Surface (Left/Right)-------**+-- Radiation -+l Heat Structure -------+-~~~~----+l DZ j Dnissl Rad Mod l l

9..... 9................ 9.. 9....,........t--ient

--t Area l Chr.L

---

t-+lVollCondlFlowl---+----t--

Mult IS -t- +......+ ......+

il Number] Name l Nod

+..+,.....+.................+...+ l Geol Altit. lOr

...+........+.....+......+.+...+....+....+.........+.........+.........

2865. 52. 52. 0.0 No Rad 6 RECT 50.3812 Horz 1. N 10 1 Ittr 2865. 52. 52. 0.0 No Rad 113 01001 SHELIA 400 1 EXT 35. 35. 0.0 No Rad

1. N 30 1 Ittr 6903. 0.0 No Rad 6 RECT 3.8 Vert 6903. 35. 35.

114 03001 SNRY.YD 400 1 EXT -- --- --- 0.0 No Rad s RECT -5.0 Horz 1.0 N O 500.0 0.85 0.9144 0.0 No Rad 115 33000 TB.BIDG-FIOGR 330 -1 EXT t>>

t4

- um

I l

l Table 4.4 Core Initial Material Mass and Parameters

)

1 Ring 1 Ring 2 Ring 3 Ring 4 Total l l

Material Mass in (kg)

UO 2 6,468.24 21,912.81 35,857.32 55,766.05 120,004.4 Zr Cladding 1,386.10 4,695.70 7,683.90 11,950.20 25,715.94 '!

Zr total 1,803.71 6,110.53 9,999.04 15,550.72 33,464.00 Poison 97.37 540.96 895.38 1,524.27 3,058.00 Inconel 162.35 549.99 899.99 1,399.68 3,012.00 Core Support Plate 277.78 941.07 1,539.93 2,394.02 5,153.71 Lower Support Structure 1,446.75 4,896.68 8,012.74 12,4.A .?.J 26,820.46 Steel total 1,745.01 5,911.68 9,763.65 15,044.66 32,375.00 Lower head 917.70 3,109.00 5,087.00 7,912.00 17,025.70 Penetration 55.60 95.30 142.90 190.60 5,632.18 Core Parameters Number of fuel assembly 13 44 72 112 241' Number'of fuel rods 3,004 9,872 16,480 25,408 54,764 Number of control rods 64 512 512 1,024 2,112 Number of instrument 4 11 18 28 61 i

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5. MELCOR RESULTS 5.1 Station Blackout (SBO) Sequence The station blackout sequence involves the loss of all ac and de power. The active safety-injection system, emergency feed-water system, containment sprays, and the cavity flooding system are assumed to be unavailable.

MELCOR predicted that dry-out of the steam generator occurs 5,500 seconds (about 1.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />) into the event. The loss of heat removal in the core region leads to core uncovery at 9,779 seconds (2.72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />) and dry-out at 11,816 seconds (3.28 hours3.240741e-4 days <br />0.00778 hours <br />4.62963e-5 weeks <br />1.0654e-5 months <br />) (Figure 5.1.1). The generation of steam causes pressurization in the reactor vessel, and gases are released through the pressurizer safety valve (PSV). The reactor vessel starts to depressurize at the time of vessel failure (12,656 seconds or 3.52 hour6.018519e-4 days <br />0.0144 hours <br />8.597884e-5 weeks <br />1.9786e-5 months <br />), as shown in Figure 5.1.2. About 31 minutes later, the vessel's pressure is reduced to the set point of the SIT (610 psig), at which time safety injection is initiated. The SIT is depleted in about 500 seconds. Since the SIT is actuated after the vessel has failed, it has no effect on core recovery and the water eventually is discharged into the reactor's cavity.

Figures 5.1.3 to 5.1.10 show the clad temperatures of each axial node in the four radial rings. These figures illustrate that upon core uncovery, the temperature of the fuel increases rapidly, causing gap release and initiating the production of hydrogen. All fuel-nodes are relocated into the core support plate in about 30 minutes. Figure 5.1.11 shows the heat-up of the core-support plate and its failure, starting at about 12,630 seconds (3.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />). Following the plate's failure, core debris is relocated to the lower plenum. The accumulation of core debris on the lower head rapidly heats up the penetration tubes located on the lower head wall (Figure 5.1.12). MELCOR predictes that a penetration tube in Radial Ring 1 fails first at about 12,656 seconds (3.52 hours6.018519e-4 days <br />0.0144 hours <br />8.597884e-5 weeks <br />1.9786e-5 months <br />).

Figures 5.1.13 shows that about 560 Kg of hydrogen is produced in the reactor vessel before the lower head penetrations fail. The release of hydrogen into the IRWST causes 9 burns in the IRWST from 11,715 s to 12,933 s.

MELCOR predicts debris will be ejected from the failed penetration tubes into the reactor cavity at about 14,094 seconds (3.92 hours0.00106 days <br />0.0256 hours <br />1.521164e-4 weeks <br />3.5006e-5 months <br />). Although the cavity flooder was not actuated, abaut 22,000 Kg of water from the SIT and lower plenum are added into the cavity.

According to the MELCOR model, the water pool is assumed to not mix with the core debris, and the corium/ concrete interaction starts immediately, at about 14,094 seconds (

3.92 hours0.00106 days <br />0.0256 hours <br />1.521164e-4 weeks <br />3.5006e-5 months <br />). Figures 5.1.14 and 5.1.15 show that the distances eroded at the end of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> are about 0.49 m and 1.55 m in the radial and axial directions, respectively. At about 50,000 seconds (13.89 hours0.00103 days <br />0.0247 hours <br />1.471561e-4 weeks <br />3.38645e-5 months <br />), axial erosion penetrates 1 meter below the concrete floor, to the distance where the containment shell is embedded. The total time to erode the entire thickness of the floor (4.5 meters)is predicted to be about 160 hours0.00185 days <br />0.0444 hours <br />2.645503e-4 weeks <br />6.088e-5 months <br /> (6.7 days).

The gases released by the corium/ concrete interaction are given in Figure 5.1.16. About  !

1,435 Kg of hydrogen and 43,000 Kg of CO are released to the containment. The addition ,

l of combustible gases to the containment's atmosphere results in one burn in the cavity 35

f I region, two in the lower compartment, two in the upper compartment, two in the annular l compartment, and one in the lower plenum of the reactor vessel during a period from

! 53,780 s to 53,839 s.

The temperatures and pressures in the containment predicted by MELCOR are shown in Figures 5.1.17 and 5.1.18, respectively. Hydrogen burns and failure of the vessel result in temperature spikes in the containment. However, the pressure in the containment is not strongly affected by the hydrogen burns. The only major pressure spike is caused by the release of hot gases at the time the vessel fails. The pressurization rate is relatively slow and it appears that over-pressurization does not threaten the containment *s integrity at the time when the corium penetrates the entire thickness of the concrete floor in the cavity (i.e.

580,000 s, or 6.71 days).

The gas molar fractions in the five containment compartments are shown in Figures 5.1.19 to 5.1.23. There is a high concentration of steam in all compartments, except the IRWST where steam is condensed in the pool. The presence of large amounts of steam in the containment prevents further combustion of hydrogen and carbon monoxide.

Table 5.1.1 shows the major events predicted by MELCOR. The table also includes a comparison with MAAP that shows, in general, reasonable agreement between the two predictions. The only exception is the extent of penetration of the concrete predicted by two codes. MAAP predicted a much smaller penetration in both radial and axial-directions. This discrepancy is caused by differences in the basic assumptions and models used in the MAAP and MELCOR codes, as described in Appendix A. The differences in the initial conditions of CCI also may contribute to the different erosion distances predicted by the two codes.

Fractional distributions of radioactive radionuclides in the core, cavity, RCS and containment regions at 14,094 seconds (i.e. about 1,438 seconds after vessel failure) are The table also compares them with the MAAP-predicted summarized in Table 5.1.2.

distribution in the containment. (No detailed distributions in other regions were reported in the MAAP analysis.) There is a reasonable agreement between the two; however, MAAP shows that nearly all noble gases, a larger fractions of Te, and a smaller fraction of Csl are retained in the containment.

Table 5.1.3 summarizes the MELCOR-predicted fractional distributions at 580,000 second Since failure of the (6.71 days) when melt-through of the cavity floor is predicted.

containment at melt-through is not modeled in the MELCOR code, no releases to the environment were predicted. The code predicted a large fractions of noble gases, Cs, Ba, I, Te,and Cslin the containment. No comparison can be made with MAAP results because none were given in Reference [1].

5.2 Small-Break Loss-of-Coolant Sequence (S-LOCA) 2 The accident is initiated by a small-break of 0.0032 m (0.034 ft:) in the cold leg of one o the coolant loops. The equivalent diameter is 2.5 inches. The accident is coupled with t 36

failure of the active safety injection, containment spray, emergency feed water, and the cavity-flooding systems.

The loss of coolant inventory out of the break when the accident begins causes a rapid drop in the level of core water, as shown in Figure 5.2.1. MELCOR predicts that the core will be uncovered at 412 seconds (6.87 minutes) and will dry out at 3,344 seconds (55.7 minutes). The loss of coolant rapidly increase.s the fuel's temperature in all core nodes (Figures 5.2.2 to 5.2.9). MELCOR predicts that the fuel starts to melt and relocate to the core-support plate at about 2,133 seconds ( 35.6 minutes) after the start of the accident.

The heat-up and failure of the core support plate at about 3,708 seconds (1.03 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />) is shown in Figure 5.2.10. Following this, core debris is discharged into the lower plenum and accumulates on the lower head wall. This causes the heat up and failure of penetration tubes located in Radial Ring 1 at about 4,733 seconds (1.31 hours3.587963e-4 days <br />0.00861 hours <br />5.125661e-5 weeks <br />1.17955e-5 months <br />) (Figure 5.2.11).

MELCOR predicts that the penetration tubes in the other three rings will fail within about 1.29 hours3.356481e-4 days <br />0.00806 hours <br />4.794974e-5 weeks <br />1.10345e-5 months <br />.

Pressures in the reactor vessel are given in Figure 5.2.12. The break in the cold leg causes an immediate drop in pressure to about 8.27 Mpa (1200 psia). The pressure increases slightly as steam is generated after the core is uncovered. However, the continued loss of coolant through the break yields e steady decrease of pressure until the core-support plate fails. Figure 5.2.12 also indicates that the core pressure decreases to the set point of the SIT (i.e. 610 psia, or 4.2 Mpa) after the vessel fails. The actuation of the SIT did not affect-the vessel's pressure, but the core region was reflooded (Figure 5.2.1). The late core recovery occurred after the vessel's failure. The injected water eventually is discharged into the reactor cavity, as shown in Figure 5.2.13.

Figure 5.2.14 shows that about 383 Kg of hydrogen is generated in the reactor vessel and is released directly into the containment. Since a large quantity of steam also is released through the break into the containment, the containment is rich in steam and combustion was not predicted to occur before the vessel fails.

The axial and radial erosion of the concrete basemat in the cavity region are shown in Figures 5.2.15 and 5.2.16, respectively. Radial erosion is practically terminated at about 100,000 seconds. However, axial erosion increases steadily and reaches 4.53 meters at the time of the containment's failure by over-pressurization. MELCOR predictes that axial erosion reaches the embedded containment shell (i.e. about 1 meter below the surface of the floor) at about 11.94 hours0.00109 days <br />0.0261 hours <br />1.554233e-4 weeks <br />3.5767e-5 months <br />. The gases released from the CCI are given in Figure 5.2.17; the total hydrogen and carbon monoxide are 1,166 Kg and 38,000 Kg, respectively.

The MELCOR-predicted containment pressure is given in Figures 5.2.18. During a brief period from 64,439 to 64,475 seconds, burns occur in the cavity, lower, annular, and upper compartments. The simultaneous burning causes a large pressure-spike of about 1.05 Mpa (Figure 5.2.18). MELCOR also predicted multiple burns in the cavity and lower compartment between 17,274 and 17,327 seconds that have no apparent effect on the l containment's pressure. In general, the pressure increases steadily at a rate of about 2.21 l pa/s due to the addition of steam and non-condensible gases from the corium/ water and corium/ concrete interactions in the reactor cavity. At about 388,000 seconds (4.49 days),  !

l 37

the containment's pressure reaches 155 psia which is the containment failure criterion assumed in CESSAR. The temperatures in the containment are shown in Figure 5.2.19.

Besides the two temperature spikes caused by multiple burns, temperatures at various compartments in the containment, except the IRWST, remain relatively steady above 500 K, which is above the containment's design temperature of 290 F (417 K). The IRWST is at about its initial temperature of 350 K.

The gas molar fractions in various compartments of the containment are shown in Figures 5.2.20 to 5.2.24. After the predicted burns end at about 64,475 seconds, the containment atmosphere in all compartments, except the IRWST, is steam-inerted and no further burns were predicted. In the IRWST, concentrations of hydrogen and carbon monoxide are negligible.

Table 5.2.1 summarizes the major events predicted by MELCOR and compares them with _

the MAAP predictions. We note that there are the following differences in modeling this small break LOCA scenario:

1. The break diameter was assumed to be 2" in MAAP, but 2.5" in MELCOR.

2. Power scram was delayed by 17.8 seconds in the MAAP analysis, but no delay was assumed in the MELCOR analysis.

3. The auxiliary feed water and containment sprays were assumed available in the MAAP analysis, but unavailable in the MELCOR analysis.

Because of these differences, MAAP predicted an initiation of the SIT injection about one hour after the core was uncovered. The injection refilled the core and delayed the failure of the vessel to about 3.44 hours5.092593e-4 days <br />0.0122 hours <br />7.275132e-5 weeks <br />1.6742e-5 months <br />. MELCOR predicted such failure at about 1.31 hours3.587963e-4 days <br />0.00861 hours <br />5.125661e-5 weeks <br />1.17955e-5 months <br />.

The SIT injection was initiated after the vessel had failed. Actuation of containment sprays in the MAAP analysis yielded a relatively low pressure in the containment. MAAP did not predict that the containment would fail due to over-pressurization up to the end of analysis (i.e. 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />).

5.3 Medium Break Loss-of Coolant Accident (MB LOCA) Sequence The accident initiator in this sequence is similar to that in the SB-LOCA sequence, except the break area is 0.0127 m2 , (i.e. 5-inches in diameter). Failure of the active safety injection, containment sprays, emergency feed water, and cavity flooding systems also were assumed for this scenario.

The large area of the break results in a rapid loss of coolant and depressurization in the reactor vessel, as shown in Figures 5.3.1 and 5.3.2, respectively. Uncovery of the core is predicted to occur at about 8.23 seconds and dry out at about 399 seconds (6.65 minutes).

At about 711 seconds (11.85 minutes), the pressure in the reactor vessel decreases to the SIT set point (610 psia) and actuates the passive safety injection system (Figure 5.3.3).

Within about 2.3 minutes, the SIT is depleted. The addition of water through the passive safety injection rapidly refloods the reactor's core. However, continued loss of coolant through the break causes the core to be uncovered again at about 975 seconds (16.75 minutes) and to dry out at about 3,300 seconds (55 minutes).

38 l

1 The clad temperatures of every axial node in the four radial rings are given in Figures 5.3.4 to 5.3.11. All fuel nodes exhibit a rapid heat-up after the first uncovery of the core. Before the actuation of the SIT, the middle and upper nodes in the first two radial rings (i.e. Nodes 6 to 15 in Radial Rings 1 and 2), and the top node of Ring 3 are predicted to melt.

Reflooding of the core due to the passive safety injection did not completely cool these nodes. Only Nodes 4 and 5 in the first two rings, and axial nodes in the third and fourth rings were predicted to be cooled by reflooding. However, these nodes are heated up again after the end of the injection. The melting and relocating of these nodes are delayed for about 30 minutes to I hour, as shown in Figures 5.3.5, 5.3.7, 5.3.9, 5.3.10, and 5.3.11.

The temperatures of the core-support plate and penetration tubes located on the lower head wall are shown in Figures 5.3.12 and 5.3.13, respectively. The core-support plate and the vessel penetration tube in the first radial ring are predicted to fail at 5511 seconds (1.53 hours6.134259e-4 days <br />0.0147 hours <br />8.763227e-5 weeks <br />2.01665e-5 months <br />) and 5,169 seconds (1.44 hours5.092593e-4 days <br />0.0122 hours <br />7.275132e-5 weeks <br />1.6742e-5 months <br />), respectively. We note that the predicted failure of the penetration tube occurs before the core-support plate fails. According to the MELCOR code, the failures of these two structures are determined by the relative quantities of the mass and temperature of core debris relocated onto each of them [3). This non mechanistic model could generate a large degree of uncertainty in the predicted time of failure.

Figure 5.3.14 shows an in-vessel hydrogen production of about 442 Kg predicted by MELCOR. Hydrogen is released directly into the containment simultaneously with a large quantity of steam. MELCOR predicted that the hydrogen would not burn before the vessel.

failed.

Figure 5.3.15 shows the containment pressure predicted by MELCOR. There is a pressure spike of about 0.325 Mpa (50 psia) caused by burns in the cavity, lower and upper compartments, between 12,438 to 12,485 seconds; after this, the containment pressure rises at a relatively stable rate of 2.23 pa/s. With a dry cavity, the containment is mainly pressurized by the non condensible gases generated the interactions between the corium and  ;

concrete. The containment pressure reaches about 0.72 Mpa (104.4 psia) at the end of the calculation (i.e. 230,000 seconds). Extrapolation of the pressurization curve shows that the containment pressure would reach to 155 psia (its failure pressure assumed in CESSAR) l at about 4.5 days. The predicted temperatures in the containment are illustrated in Figure l 5.3.16. Temperatures in various compartme'nts of the containment, except the cavity, are at or below the design temperature of 417 K (290 F), The cavity's atmosphere is about 500  !

K.  ;

1 The gas molar fractions in various containment compartments are given in Figures 5.3.17 j to 5.3.21. After the brief period between 12,438 and 12,485 seconds, the atmosphere in all l compartments, except the IRWST, become steam inerted and the concentrations of l hydrogen and carbon monoxide are less than the flammability limits modeled in the MECLOR code. In the IRWST, concentrations of hydrogen and carbon monoxide are l negligible.

1 The MELCOR-predicted axial and radial erosion of the cavity concrete are shown in Figures 5.3.22 and 5.3.23, respectively. Axial erosion reaches the embedded containment shell at about 36,000 seconds (10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br />), and 1.75 meters at the end of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

39

I ll l

l Extrapolation shows that axial erosion would reach 2.75 meters by the estimated time of containment failure (via overpressurization). Thus, basemat melt-through is unlikely to occur prior to containment failure by overpressurization for this MB-LOCA scenario.

0.72 Similar to the small break 1.OCA, radial erosion is relatively slow, covering about meters at the end of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

Oases generated by CCI are shown in Figure 5.3.24; there are about 442 Kg of hydrogen and 30,000 Kg of carbon monoxide at the end of the calculation (i.e. 230,000 seconds).

MELCOR also predicted a continuous release of steam from corium/ concrete interactions, Since the resulting in a steam-rich atmosphere, as given in Figures 5.3.17 to 5.3.20.

containment atmosphere is steam inerted, the combustible gases were not predicted to burn.

However, all the non-condensible gases and steam contribute to pressurization of the containment.

Table 5.3.1 summarizes the major events predicted by MELCOR. Since the MP-LOCA scenario was not included in the MAAP analysis [1], the MAAP prediction for a large break sequence was included in Table 5.3.1 for comparison. In addition to the difference in the size of the break, the auxiliary feed water was assumed available in the MAAP analysis, but not in the MELCOR analysis. The availability of the auxiliary feed water delays uncovery of the core and failure of the vesselin the MAAP calculation. MAAP also predicted that, instead of over pressurization, melt-through of the cavity basemat occurs at about 8.3 days, about four days later than the time of containment failure predicted by MELCOR due to-over-pressurization.

5.4 Sequence for Steam Generator Tube Rupture (SGTR)

Case 1 SGTR With Functional MSSV Rupture of two tubes in one of the steam 2generators (Loop A) was assumed for this m , which corresponds to the rupture of two accident scenario. The break area is 0.00045 tubes. The failure of both the main and auxiliary feed water, the active safety injection, containment sprays, and the cavity-flooding systems also were assumed for this scenario.

The leakage of primary coolant into the steam generator (A), coupled with the failure of the feed water to both steam generators, causes a rapid heat-up and rise in pressure in the secondary side of the steam generators. Figure 5.4.1 illustrates the pressure rise from the initial 6.610E6 pa (957 psia) to the set point of the safety-relief valve (i.e 8.10 Mpa or 1175 psia). The secondary side of the failed steam generator (A)is rapidly depressurized shortly after the vessel fails at 11,674 seconds (3.24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />). The water volumes in the secondary side of the steam generators A (failed) and B (intact) are given in Figures 5.4.2 and 5.4.3, respectively, to illustrate the dry-out in the steam generators as a result of loss of feed water.

The MELCOR-predicted water levels and pressures in the reactor vessel are shown in Figures 5.4.4 and 5.4.5, respectively. Following loss of coolant through the ruptured tube in steam generator A, the water level and pressure decrease in the reactor vessel. Uncovery of the core is predicted to occur at about 5,930 seconds (1.65 hours7.523148e-4 days <br />0.0181 hours <br />1.074735e-4 weeks <br />2.47325e-5 months <br />), and dry-out at about 40

I l

10,899 seconds (3.03 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br />). Due to continued generation of steam in the reactor core, the reactor's pressure is maintained above the set point of the SIT (i.e. 4.21 Mpa, or 610 psia) until the vessel fails at 11,674 seconds (3.24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />). Thus, SIT is actuated after vessel failure and the water is added to the lower plenum of the reactor ves.sel (Figure 5.4.4). The I I

SIT water then is discharged into the reactor's cavity.

The clad temperatures of each node in the four radial rings are given in Figures 5.4.6 to 5.4.13. The fuel rods heat up rapidly after the core is uncovered. Fuels in Radial Ring 1 reach to the clad failure-temperature (1650*F or 1173 K) at about 7,868 seconds, at which time gap release starts. MELCOR predicts that fuel will melt and relocate the Radial Ring 1 at 8,142 seconds (2.26 hours3.009259e-4 days <br />0.00722 hours <br />4.298942e-5 weeks <br />9.893e-6 months <br />). Within about 41 minutes, fuel in all four radial rings relocates to the core-support plate. The heating and failure of the core-support plate at 11,651 seconds (3.24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />)is shown in Figure 5.4.14. Figure 5.4.15 shows the temperatures of the lower-head inner wall and penetration tubes attached to the wall. MELCOR predicted that the failure of the first penetration tube started at 11,674 seconds (3.24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />).

Figure 5.4.16 shows that 550 Kg of hydrogen is produced in the reactor vessel before it fails.

There is no hydrogen burn in the containment before the vessel fails, because it is released directly to the main steam-line house through the ruptured steam-generator tubes.

The pressurization of the containment predicted by MELCOR is given in Figure 5.4.17.

The discharge of SIT water into the cavity after the vessel fails causes the generation of a.

large quantity of steam from corium/ water interactions in the cavity. With steam added to the containment, the containment's pressure increases rapidly until about 48,440 seconds (13 hours1.50463e-4 days <br />0.00361 hours <br />2.149471e-5 weeks <br />4.9465e-6 months <br />) when the SIT water is completely boiled off. Subsequently, the containment is pressurized at a relatively low rate by the release of non-condensible gases from corium/ concrete interactions. Extrapolation shows that the containment pressure would reach 155 psia, (i.e. the assumed failure pressure in CESSAR), at about 678,000 seconds (7.85 days).

Figure 5.4.18 shows the temperatures in the containment predicted by MELCOR.

Temperatures in all containment compartments, except the IRWST, are above the containment design temperature of 417 K after the water in the cavity region is depleted.

The axial and radial erosion of the cavity's concrete floor are shown in Figures 5.4.19 and 5.4.20, respectively. Axial erosion reaches the embedded steel shell located 1 meter below the floor surface at about 57,000 seconds (15.8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />), and reaches 1.38 meters at the end of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The maximum radial erosion during the entire transient is only about 0.34 meters.

Figure 5.4.21 shows the accumulated gases released from the corium/ concrete interaction; large quantities of carbon monoxide and carbon dioxide are released into the containment.

At the time of failure of the containment, the total quantity of combustible gases in the containment are 35,000 Kg of CO and 1072 Kg of hulrogen. No combustion was predicted by MELCOR due to the presence of a high fr . twn of steam, as shown in Figures 5.4.22 to 5.4.25. In the IRWST, the fractions of hymogen and carbon monoxide are negligible (Figure 5.4.26).

41

The major events are summarized in Table 5.4.1. Our findings cannot be compared with MAAP results because no such analysis was reported [1].

I Figure 5.4.27 summarizes the release of radioactive radionuclides from fuel in the reactor vessel, and the release to the main steam line house from the ruptured steam generator tubes (Figure 5.4.28). Among the several classes of radionuclide released from the fuel, only the noble gases, CsOH and CSI are released to the main steam line house. The others radionuclides apparently are retained in the reactor vessel, and some are released to the environment after the containment fails.

Table 5.4.2 summarizes the fractional distribution at 11,791 seconds (3.28 hours3.240741e-4 days <br />0.00778 hours <br />4.62963e-5 weeks <br />1.0654e-5 months <br />) about 117 seconds after vessel failure. MELCOR predicts that most of the radionuclides, except the noble gases, are still retained in the reactor's coolant system. A MAAP analysis for this accident scenario was not performed.

Case 2 SGTR with stuck open MSSV In this sequence, a stuck-open MSSV was assumed in addition to a SATR. The rupture of two tubes in steam generator (A) coupled with the failure of feed water and the active safety injection systems also were assumed. However, the cavity-flooding system and containment sprays were assumed operable. Cavity flooding is activated at the initiation of the accident and containment sprays are actuated when containment's pressure reaches 20-psia. The scenario is similar to that analyzed by MAAP, reported in Reference [1].

The rupture of tubes coupled with the failure of the active safety injection results in depressurization of the reactor vessel and primary system inventory, as shown in Figures 5.4.30 and 5.4.31, respectively. The inventory loss eventually leads to core uncovery at about 4,881 seconds (1.36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />) and dry-out at about 9,896 seconds (2.75 hours8.680556e-4 days <br />0.0208 hours <br />1.240079e-4 weeks <br />2.85375e-5 months <br />). Because the RCS pressure is maintained above the SIT set point (610 psia), the SIT injection is started after the reactor vessel fails, which occurs at 11,772 seconds (3.27 hours3.125e-4 days <br />0.0075 hours <br />4.464286e-5 weeks <br />1.02735e-5 months <br />). This water is discharged into the reactor cavity.

The loss of primary coolant through the failed steam generator and the lack of RCS coolant make-up result in the fuel heat-up, shown in Figures 5.4.32 to 5.4.39. The failure of the core-support plate predicted by MELCOR starts at about 10,813 seconds (3.0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br />) and failure of the lower-head penetration tubes starts at about 11,772 seconds (3.27 hours3.125e-4 days <br />0.0075 hours <br />4.464286e-5 weeks <br />1.02735e-5 months <br />), as given in Figures 5.4.40 and 5.4.41, respectively. Figure 5.4.42 shows a total hydrogen production of about 568 Kg before the vessel's failure. Most of the hydrogen would be discharged through the ruptured tubes and the open MSSV to the main steam line house.

Figure 5.4.43 displays the water poolinventory in the cavity region. It is assumed that the cavity-flooding system is activated at the initiation of the accident, and there are about 305 cubic meters of water in the cavity. At the time of vessel failure (11,722 seconds), the casity water is increased to about 345 cubic meters due to the discharge of the SIT and residual water from the reactor vessel. At about 24,000 seconds, the containment sprays are activated by high pressure in the containment. The spray water is collected in the hold-up I

I 42

l tank in the IRWST and overflows into the cavity. Figure 5.4.43 shows that the water in the cavity increases steadily and the cavity is completely flooded over the entire transient.

i The molar fractions of gases in various compartments of the containment are shown in i Figures 5.4.44 to 5.4.48. These figures reveal that the steam content is reduced by sprays ,

and combustion in the containment. According to MELCOR calculations, combustion I occurs in the cavity region immediately after the vessel fails at about 12,825 seconds.

Multiple burns also occur in the cavity, IRWST, upper, annular, and lower compartments between 32,106 and 32,119 seconds. This multiple combustion causes a spike in pressure and temperature in the containment (Figures 5.4.49 and 5.4.50). However, due to the actuation of sprays, both pressure and temperature are generally maintained at low levels; MELCOR predicts that the containment is unlikely to fail by over-pressurization.

The axial and radial erosion of the cavity basemat and gases generated due to the corium/ concrete interaction are given in Figures 5.4.51 to 5.4.53, respectively. According to MELCOR calculation, the erosion of the cavity basemat is only 0.92 meters at the end of 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br />, about 20% of the thickness of the basemat. Axial erosion would be about 1.48 meters when extrapolated to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

The major events predicted by MELCOR for this scenario are summarized in Table 5.4.4, which includes a comparison with MAAP predictions. In the MAAP analysis, a stuck-open MSSV was assumed for both steam generators A (broken) and B (unbroken). The same, assumption also was used in the MELCOR analysis. Although both codes have the same assumptions, MAAP predicted an earlier uncovery of the core and failure of the vessel than MELCOR. There is no major difference in the containment's performance between the two predictions. Calculations were terminated at 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> in the MAAP analysis, and 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br /> in MELCOR. Both codes predicted that the containment had not failed at the end of the calculation.

The MELCOR-predicted radionuclides released from fuel and released to the main steam line house through the ruptured tubes and stuck-open MSSV are shown in Figures 5.4.54 and 5.4.55, respectively. The fractional distributions of the radionuclide at 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br /> (end of calculation) are summarized in Table 5.4.5, which compares these values with the MAAP-predicted releases to the environment. Table 5.4.5 shows that MAAP predicted releases to the environment are much higher than the MELCOR-predicted releases to the main steam-line house for all classes of nuclides, except the noble gases and CsOH.

43

l l

SYSTEM .

80+ .SBO. (LIMESTONE-DRY

.. . . . CAVITY)

. . i 20 . '

DOME -

j _._%.- UPP-PLENUM 18 -

--m-- CORE 3 ~

_ ., - BYPASS j

16 -

--O - LOW-PLENUM -

^

1 ANN-PLENUM E 14 - "

^ '

i - - VB of 12656 sec v

j -

W , .

2 W 12 -

1  :

w  : -

8 j

9 10 -

tn ._._ -._. +_._._.s,  ;; -

o_  :

u a 8 -

- - + - ---m- e '*--p--n----+-----+--.--

d O

6 -

i. -

s  !

4 -

--se--r -

% b - e _.- w - e- e - -

e - - e- -

=

2 -

0 20 25 30 5 10 15 0 3 l NONE TIME (10 s)

System 80+ MELCOR 10/04/93 16:09:36 JDDOATNNM i I

I

\

Figure 5.1.1 Vessel Collapsed Liquid Level Predicted by MELCOR for SBO Base Case Sequence l

SYSTEM 80+ SBO (LIMESTONE-DRY CAVITY) .

20 , . . .

^

DOME 18 -

--+-- UPP-PLENUM

- 2.5

- - se- - CORE 16 i k 3 _ .* - BYP ASS

{3 3 } -- o -- LOW-PLENUM g 14 - -

j v- ANN-PLENUM

- 2.O T m' T . 0' O-  : -

PRESSURIZER M o

o .

is -

C c 12 -

;; ......-- vs at 12656 see w

' ' w a:

o -  : 11 _

15 " O m 10 _ .

. m m

m  : W w -

m m  : o-o- 8 -

i t E -  ! i b - 1.O E O 6 -

!l l -

O 4 -

' .5 i -

2 -

i -

^ ^ '

0 ' ' ' ' '

" ' T ^ -~' -

.O O 5 10 15 20 25 30 NONE TIME (103 s)

System 80+

JDDQATNNM 10/04/93 16:09:36 MELCOR Figure 5.1.2 Primary System Pressure Predicted by MELCOR for SBO Base Case Sequence 9

l I

\

l l

l l

I i

l l

4 SYSTEM 80+ SBO (LIMESTONE-DRY CAVITY)

I . i

=

f 2.50- .

0 COR115

+- COR114 2.25 -

- sa - COR113 -

-v- COR112 _ 3 g 2.OO _

-E3- - COR111 -

"a O

m

^-

-e - COR110 8 1.75 -

E q

1.50 - - 2 mw R

g -

S E 1.25 -

y

.u a

2w Q

a a 1.00 -

- 1 0

< /t -

m d .

- 0.75 -

,- f7 2-h

!E & _

" O.50 -

-0 O.25 --

^ ' ~ "^' - -'

0.00 15 20 5 10 O

3 TIME (10 s) 1 Clad Temperature Predicted by MELCOR for SBO Base Case Sequence Figure 5.1.3 Core Ring 1 (node 110-115)

2.50-SYSTEM 80+ SBO (LIMESTONE-DRY CAVITY)

, , , , . . . - 4 t COR109 2.25 -

. . . . + . . COR108

~

us- COR107 I m 2.00 -

--w-- COR106

~

m a x - - 3 u_ l m

g

- -EF - COR105 "a C

g c 1.75 -

_ _e - COR104

~

I N N a 1.50 -

E g 1.25

- h, e

- 2 @

g W g,, W o 1.00 -

i; ' -

o D 5 o l -

5 o

1 0.75 -

(C5 W,

@ g -_ . _ . -

g g q g 0.50 -

L O.25-- ~ ~ c5 -- O o

O.00 ' ' ' ' * * "- ^' ----

0 5 10 15 20 TIME (103 s)

Figure 5.1.4 Core Ring 1 (node 104-109) Clad Temperature Predicted by MELCOR for SBO Base Case Sequence

SYSTEM 80+ SBO (LIMESTONE-DRY '

CAVITY)' '

2.50- i i i i t COR215

~

- - + - - COR214 2.25 -

as- COR213

~

2.00 - -v -- COR212 _ 3 mC y -e- - COR211

- o 5 1.75 - -e - COR210 ]

w

" 1 50 -

?

Q ,

2 $

a i , _

g 1.25 -

13 w

3 a

g a 1.00 -

P $

5 o - 1 O f _

m n 0.75 - -

l; 5 6 m _ _ _ -  : C - < 25

z_:

m

_" O.50 -

o r

. . -- 0 0.25 --

• ja u

, , , , _ _ . ,- o 0.00 20 O 5 10 15 TIME (103 s)

Figure 5.1.5 Core Ring 2 (node 210-215) Clad Temperature Predicted by MELCOR for SBO Base Case Sequence

__ mM

SYSTEM 80+ SBO (LIMESTONE-DRY CAVITY)

. - 4 2.50- . . . . . .

i COR209 2.25 - .... ..

COR208 us- COR207 2.00 - _ _ ,- - COR206

_3 g "o

- - D- - - COR205 "o - O O 1.75 -

_ _e - COR204 w

w & ce cr

? 1.50 - l 3

< 'li -2 ce m

5 g 1.25 -

W o 1.00 -

il

<i

((i o

u <

d , I - 1 d m

m 0.75 -

p 9 -: - c -- e : == d* o E

5 E O.50 -

~

O.25-- --O i

O.00 0 5 10 15 20 3

TIME (10 s) i Figure 5.1.6 Core Ring 2 (node 204-209) Clad Tennperature Predicted by MELCOR for SBO Base Case Sequence

i SYSTEM 80+ SBO (LIMESTONE-DRY CAVITY) 2.50- . . . . . . . - 4 i COR315 2.25 -

....+.. COR314 su COR313 2.00 -

__,-- COR312 g _

_ 3 g "o - - O- - COR311 "a C 1.75 -

_ _e - COR310 O

w w m x R 1.50 - -

R m -

- 2 mm m

n w

1.25 - -

w

& g >--

u o 1.00 -

> - o o < , <

a ,. a v . rn _ j u m 0.75 - -

m km O.50 r; - : c = ; -: - C - II h

oc o -

o 0.25 - - -- 0 0.00 ' ' '

0: '

= ?::

O 5 10 15 20 TIME (103 s)

Figure 5.1.7 Com Ring 3 (node 310-315) Clad Temperature Predicted by MELCOR for SBO Base Case Sequence

l l

l SYSTEM 80+ SBO (LIMESTONE-DRY CAVITY) 2.50- . . . . . . . - 4 t COR309 2.25 -

....+.. COR308

- su COR307 g 2.00 -

__ ,-- COR306

~

g

_3 "

"o - - D- - COR305 O

O C 1.75 -

,7 .- -e - COR304 w w m m R

1.50 -

L

?

$ ~

h - 2 5 gi; 1.25 - -

3; w 1 5 w u

~

j ,

o 1.00 - F - o 4 i ) <

-n s

" O

~

l - 1 m 0.75 -

m m 0.50 2

t v -: c=;= C # I a

O.25- - --O su d

O.00 '

't c '=O d c 0 5 10 15 20 TIME (103 s)

Figure 5.1.8 Core Ring 3 (node 304 309) Clad Temperature Predicted by MELCOR for SBO Base Case Sequence

l I

l l

l l

I 1

i SYSTEM 80+ SBO (LIMESTONE-DRY CAVITY) , ,

, , - 4 j 2.50 - , ,

( COR415

\

0 -

2.25 -

. . 4- - COR414 us- COR413 -

COR412

_ 3 "g g 2.00 ,

-v- O

• - - D- - COR411 - O o

G 1.75 -

-*- COR410 W N

R R

1.50 -

]5-4' - 2 $

3

% 1.25 -

.. W o

W r v, o 1.00 -

o

" 5 o t 0.75

- ' 9 L

g.

2 =:== : = =:: ==

r E

" O.50 -

JL -O i O.25 --

is l

' ' ' ' ' ' '*v  :: i 0.00 10 15 20 l O 5 3

TIME (10 s) i Case Sequence l Clad Temperature Predicted by MELCOR for SBO Base Figure 5.1.9 Core Ring 4 (node 410-415)

I i

i

2.50.

SYSTEM 80+ SBO (LIMESTONE-DRY CAVITY)

. . . . . . . - 4 t COR409 2.25 -

....+.- COR408

~

us- COR407 g 2.00 -

--v-- COR406

~

g

_3 "

"o - - D- - COR405 O

O C 1.75 -

- -e - COR404 N N E

1.50 - -

E 5 -

p -2 $

h

$ 1.25 -

f t) -

a W 'h f W Q 1.00 -

N -

Q d

d ' N

-e d

,,. O.75

~

// N -

~

_ g _g.: c= b .4 Q

3 g_ Q O.50 - -

It O.25-- 15 --O

[]

O.00 ' ' ' '

=

0 5 10 15 20 TIME (103 s)

Figure 5.1.10 Core Ring 4 (node 404 409) Clad Temperature Predicted by MELCOR for SBO Base Case Sequence e

SYSTEM 80+ SBO (LIMESTONE-DRY '

CAVITY) ' ' _

2.50- i i i O COR103

~

. . . . .e- -

COR203 2.25 -

us - COR303 2.00 - --v-- COR403 -3 C 2 -

"o m _. C 8 1.75 -

~ ___ m-y. -- w

g 5e ' ' * ,,

g >

o

~ 1 50 -

M <-.

_2 x

w x -

o_

w Ii -

E o- 1 25 - * .I ' w 1 .. o w w .+ i

& =

• _ w u w 1.00 -

. / 'l Q u n a .. e a

< 1 o_

__. _ s Y _

w 0.75 -

a

< [ ', l W

O "o =0  ? -

o 0 0.50 -

_ _o 0.25 -

O.OO 40 O 10 20 30 3

TIME (10 s)

Figure 5.1.11 Core Support Plate Teinperature Predicted by MELCOR for SBO Base Case Sequence

- -M

SYSTEM 80+ SBO (LIMESTONE-DRY CAVITY) - 4 2.50- . . . . . . .

....+.. RING-1 2.25 -

- + - RING-2 m- RING-3 g 2.00 _

--v-- RING-4 - 3 C "a ,

O LOW-HEAD "o C 1.75 -

- O w w

' 6i: .jk,f

% 5 5

.-- 1.50 -

g .

1  : a- l g _ -

-2 $

$ 1.25 - <

,/

t7 w -

s u z 1,00 -

8 t il se _ z 9

~

Y

\ l

+*

9

~

.g8  : _ 1 <

E

$ O.75 -

9 1g -

y .. - a k I ,, W w - _ . . .

- m a_

o- O.50 - 9 -

O.25- - --0 0.00 O 10 20 30 40 TIME (103 s) l Figure 5.1.12 Lower IIead Inner Surface and Penetration Temperature Predicted by MELCOR for SBO Base Case Sequence l

l l

SYSTEM 80+ SBO (LIMESTONE-DRY. CAVITY) 650, . . . . i i i . . i

_ 1,4 600 -

550-- --- 1.2 2

g 500 -

450- -

1.O 8 5 :2r 5a 400 -

~

~

'8 S 8

oc 350 -

o a_ ne m 300 -

m g g -

.6 m

• 250 -

W o

200 -

.4 w m

o o a;; 150 -

H2' M_

100- - +- Co -

.2

- - sm- - CO2 50 P- -

v- CH4 O d f0 '

=' T'O '= ' -- t 5 '

T O'  :

0 100 200 300 400 500 600 TIME (103 S)

Figure 5.1.13 In-Vessel Ilydrogen Production Predicted by MELCOR for SBO Base Case Sequence w ___a _ u ._. 2m- _________._______.._.__._._._.a._ -

.h- i h

L 6.0 SYSTEM 80+ SBO (LIMESTONE-DRY CAVITY) . . .

. .. , , , i i i .

5.5 -

i .i 5.0 -

4.5- -  !

M - 15 m  : p v

s 4.0 -

v u_

m 3.5 -

m-O s

b o 3.0_ -

e -- 10 s o w LLE Laj w o  : o-

>- 2.5 -

i -

9-- *

> t o 2.0 - -

. o 1.5- -

-5 i

l 1.0 -

i. -

O AXIAL PENETRATION O.5 . j --

24 HOURS

~

J ' ' '

l 0.0 ' ' ' ' ' ' ' '

O O 100 200 300 400 500 600 3

l . TIME ~ (10 S)

, Figure 5.1.14 CCI Cavity Maximum Axial Penetration Predicted by MELCOR for SBO Base Case Sequence i

l l

l l

_ _ _ _ _ - _ - _ . - -_ . _ _ . . . .:-~ . . . - . . . - - -- .. .. . - _ - . . . .

SYSTEM 80+ SBO (LIMESTONE-DRY , . . ,

CAVITY) ,

1.0 . .. , ,

- -3.0 0.9- -

0.8 -

! - 2.5

!. - m 9---

m O.7 -

i. b y

~ i r- 2.0 >_

: m

>- 0.6- -

i  : &

m.--  :. w w

2 0.5 o -

1.5 "e m o .

ao C 0.4 -

i t-5  : -- 1.O 5 U O.3- - o i 0.2 -

i -

.5

- RADIAL PENETRATION _

0.1 -

........ 24 HOURS 3

.o O.O ' '

100 200 300 400 500 600 0

TIME (103 S)

Figure 5.1.15 CCI Cavity Maximum Radial Penetration Predicted by MELCOR for SBO Base Case Sequence l

1 mg

SYSTEM ,80+ SBO (LIMESTONE-DRY, CAVITY) .

100 , . . . . , , .

90- - -- 200 80 -

o en M

a 70 - - -

150 W o O C w 60 - - w w m w w d 50 - - d x

m

$ m

'~,____y_______e 100 m

$ 40 -

1. ~ , ,

-r -

5

>- ' A , >-

w , '

s--

5 30 -

,- ,,,,. _ . _ . _ . 5

< , ... 4 O

O e 'a7

- ^

H2 - 50 20 -

,'W " -

,s ,g ',,.

• H2O

~~"~~ CO 10 - s' '

,8 ,, , _ p _._w.- CO2

'* ^~ # 0 0-0 -

0 0 100 200 300 400 500 600 TIME (103 S)

Figure 5.1.16 Cavity Gases Production Predicted by MELCOR for SBO Base Case Sequence

N SYSTEM. 80+. SBO .

(LIMESTONE-DRY

. . . . . CAVITY) 1.3 .

1.2 -

1.1 -

- 150 c;

9 1.0 -

- o 2-8 0.9 -

5 E 0.8 - g a <> -

'1 0 0 Mo-O O.7-- LE

+--

E 4 -

O.6 - i p 25 S E O5 -

W < >

k O.4 -

d ' t UPPER - 50 8 E -

. . . .O - LOWER

~

8 0.3 -

--v - ANNULAR _

0.2 -

- - o- - CAVITY -

- - IRWST O.1 O

0.0 300 400 500 600 O 100 200 TIME (103 s)

Figure 5.1.17 Containinent Pressure Predicted by MELCOR for SBO Base Case Sequence

1.5 SYSTEM 80+ SBO (LIMESTONE-DRY CAVITY) 1.4 -

9 - - + - - IRWST(otms) _

[] --v-- CAVITY (otms) - 2.O 1.3 -

- - e- - UPPER (alms) g 1'2 -

o --e-- ANNULAR (atms) _ C "g th --a-- LOWER (otms) "g 1.1_ -

c3

- 1.5 w <> w m >

m a 1o j - o e- >

c) +--

< < > a <

• > 5 7 0.9 <>

4 > {l A

.e s a

~

W O.8-l [ t ) ,, -- 1.O g

,__ t > s 5 0.7 4

• i g -

,5 s k . < > s E O6 2 " O, E

< < > ___-e,,- <

~

0.5 b-- -*----- " " ^ "#~~ ~ i~ '

o < > ; s-amm. * : >~"

,____g.' - e"

~ ~ E_hkN o

i r 7--e-O.4 ,

_ _ _ _ _ _ 4 _ _ _ 4 _ _ _ _ _ _ _ p _ _ _ _ _ _-

O.3 2 -

.O O.2 ' ' ' ' ' ' ' '

O 100 200 300 400 500 600 TIME (103 s)

Figure 5.1.18 Containment Atmosphere Temperature Predicted by MELCOR for SBO Base Case Sequence

SYSTEM 80+ SBO (LIMESTONE-DRY CAVITY) 1.0 . . . . . . . . i i i

^

STEAM O.9 -

-._,u.- 02 H2 Z O.8 -

--m-- co2 2

2 a co

~< 0.7 - -

W Z

o ^ m V

CL O.6 -

CL

• D z_

O.5 - -

Z 52

>- 0.4 - -

! O l

0 E O.3 -# -

g 0.2 .

01 j,% ----_ , , __ ,,_-=- w ----- m - --i O --

f -$._ - _ _ _ _ _ _ _ _ _ _ _ _ _ _

---"#>~V,~~-'-'_-'-'-^'-',--~~'-'______- '- '-' - '-- * '

O 100 200 300 400 500 600 TIME (103 S)

Figure 5.1.19 Gaseous Mole Fraction Distributed in Upper Compartment of Containment Predicted by MELCOR for SBO Base Case Sequence 1

t -1 +-t is-vd n w e,

SYSTEM 80+ SBO (LIMESTONE-DRY CAVITY) 1.0 . . . . . . . . . . .

O STEAM O.9 - _._ ,m.- 02- i

_ -9 - H2

~

3 0.8 -

--m-- CO2

• - o- CO z

@ 0.7 -

z o .

a v 0 0_

0.6 -

W oJ O.5 -

z_

z .

o

_ O.4 -

m -

u o E O.3 -t M

o s O.2 e. -

s r.

0*' ' >W~*1-----p , _ _ -_.__--g ---

_ 9

._--:2

_ e . V

• r * * - * -1 * - *__T r

• ___,______w__

- %_ , _ 7r _- - *_y*-*-*,- __ __ y ._. -

• 1 - - - * -r- * -

• T * - - a r- P * -

0 100 200 300 400 500 600.

TIME (103 S)

Figure 5.1.20 Gaseous Mole Fraction Distributed in Lower Compartinent of Containtnent Predicted Predicted by MELCOR for SBO Base Case Sequence

1.O SYSTEM 80+ .

SBO (LIMESTONE-DRY CAVITY)

^

STEAM O.9 -

---v- - 02

- -9 - H2 Z O.8 -

--m-- CO2

s

g; O CO

< 0.7 - -

D--

Z O ^

Y 0.6 -

- 0 0 _

Z Z

O.5 - -

z_

l Z 52 H

0.4 - -

i ch j b U t

l E O.3 -

t.a J

l C) O.2 . -

l :E s

O.1 i

! O N . } - - - - - -j p m - a g - - - =_= - ut g- - - =.= -m=g - - - -~

f, .f.

- ,v**

M -*- r-. n. ,y.-. ,.-. g -- --. 7- 9 .,_ . _ . r - - - - V7 - - - -- e r - - -

---,----w-0 100 200 300 400 500 600 3

TIME (10 S)

Figure 5.1.21 Gaseous Mole Fraction Distributed in Annular Compartment of Containment Predicted by MELCOR for SBO Base Case Sequence

SYSTEM 80+ SBO (LIMESTONE-DRY CAVITY) e e i 1.O i i i i i i i i

^

STEAM-O.9 - _._v-.- o2

- H2 0.8 - --m - co2 a Co u

sc O.7 -

95 -

z_ O.6 -

z <> -

o O.5 g a < 8 > -

E O.4 d k <>

3 0.3 -

0.2 -

l g _ c O  : .____,,,__

u__- ________m__

O.1 h

... ~~~ *' - - -.-.v._,

--e - - -e - -

w _W-_ 'g. ----r-----m--_-----.,_-

-g_ _

, y. ,_._._._._._,_._._..._._ ,._._.-.

O.O -

0 100 200 300 400 500 600 3

TIME (10 S)

Figure 5.1.22 Gaseous Mole Fraction Distribution in IRWST Predicted by MELCOR for SBO Base Case Sequence

l I

SYSTEM 80+ SBO .

(LIMESTONE-DRY CAVITY)

. . . . i 1.O i i O STEAM

- -vu.- 02 O.9 -

- -9 - H2

--m - co2 0.8 -

-o-co "'

O.7 -

< C C C -

O 0.6 < >

3 J>

z >

r -

9

~

0.5 <

m <>

m <o

< g' \ -

E O.4 -

b o

1 O.3 -

1 0.2 e.

0*1 -' 's gn --- --f

{..k------p -_ __ p _= - 4 --

du - .- e - - _ g -- ----,------e-----

( -'-~~'--'-"-'-'-"*--'-'"*'-'-'-^'-'

O.O 8 - '

500 600 O 100 200 300 400 3

TIME (10 S)

Figure 5.1.23 Gaseous Mole Fraction Distributed in Cavity Predicted by MELCOR for SBO Base Case Sequence

SYSTEM 80+ S- LOCA (LIMESTONE-DRY CAVITY) 16 . . . . . . . . .

t DOME j4 _

4- -

UPP-PLENUM _

= CORE

- - - v- - BYPASS 7 12 -- s-- LOW-PLENUM w t - -3E - ANN-PLENUM d

> 10 - Y -e- PRESSURIZER _

w I l . . . .

W 8 --

1 -

n. .

../g..........e...............e...... g.a...............e...............e...

_J >

_J '

e o 4 O s _ t -

. I w I l y a:

8 4 - -

-e- - -

es- - - - = F = v =

2 -

dp__v_ ,_ __ _ _x_ _ _

s \

O ' ' ' ' -"" ---"----- ^~

O 2 4 6 8 10 NONE TIME (103 s)

System 80+

CPEOAPHNM 3 / 16 / 9 4 14:06:53 MELCOR Figure 5.2.1 Vessel Collapsed Liquid Level Predicted by MELCOR for S-LOCA Base Case Sequence

SYSTEM 80+ S- LOCA (LIMESTONE-DRY CAVITY)

. . -4 2.50- . . . . . . .

i COR115 2.25 -

. . . . + . - COR114 us - COR113 2.00 -

--v-- COR112

- 3 m u_

x -

- - - E}- - COR111

• m a g -

C c 1.75 -

- -e - COR110 w

w Z N <> -

2 R 1.50 -

4 -

- 2 g 5  ; -

g g 1.25 -

i W

W .J ..

i

> - a

&a 1.00 -

!i 5 5

o -

_ j u m O.75 -

E u __ _m --

- -- a

- --- l' g'  ;

?

g -

O.50 -

4 k

t.

O.25- - g

-- 0 0.00 0 1 2 3 4 5 TIME (103 s)

Figure 5.2.2 Cort Ring 1 (node 110-115) Clad Temperature Predicted by MELCOR for S-LOCA Base Case Sequence

SYSTEM 80+ S- LOCA (LIMESTONE-DRY CAVITY) 2.50- i i i i i i i i i -4 0 COR109 2.25 -

+- COR108

-m- COR107

~

_ 2.OO -

--v-- COR106

_3 g m - - D- - COR105 "a 8 1.75 -

<> - -e - COR104 O

w M =

M R 1.50 -

?

3

5 -

?! /, -2 $

$ 1.25 .b ' 's -

Sig m

- > , u w a

n [t-o T o

a 1.00 -

/ 's -

• f k a i 3 d .

k '

s t

- 3 o

- O.75 - 18 's -

=

d3 k

• O E "rO_ -- arOr :I c_ Y E

=

0.50 -

q p >ay % 'i, i

O.25- - -- O i,

4>

0.00 ' ' '

= o :: '

0000 :

0 1 2 3 4 5 TIME (103 s)

Figure 5.2.3 Core Ring 1 (node 104-109) Clad Temperature Predicted by MELCOR for S-LOCA Base Case Sequence

.i

SYSTEM 80+ S- LOCA (LIMESTONE-DRY CAVITY) 2.50 . . . . . i i i i - 4 1 t COR215 2.25 - .... ..

COR214

- un - COR213 m 2.00 -

--v-- COR212

-3

^

w x -

- - - D- - - COR211 "a ~

O O

G 1.75 -

. - -e - COR210 w ,!r; w

= m 5 1.50 -

id( -

?

< y5 -2 5 -

S l

w  % 1.25 -

w w is >-

O w g 14, .

1 o 1.00 -

t - o l

a U

m 0.75

/

1 '

• ((4 -

- 1 a

m U

U a _. - -_.

• / \, g g

O.50 - 1 ; \ -

l.

0.25- - < lit -- O O.00 ' ' ' ' ' 'I' ' - - ' - ' -~-

0 1 2 3 4 5 TIME (103 s) i Figure 5.2.4 Core Ring 2 (node 210-215) Clad Temperature Predicted by MELCOR for S-LOCA Base Case Segw nce

,f

SYSTEM 80+ S- LOCA (LIMESTONE-DRY CAVITY) 2.50- , , , , , , , , ,

-4 t COR209 2.25 -

COR208

~

as - COR207 g 2.OO -

--v-- COR206

~

g

_3 "a - - D- - COR205 "o G 1.75 -

- -e - COR204

~

O M 5 W R 1.50 -

!  ?

!{

p.p -2 $

% 1.25 - - '

7 /k -

W ' >

/ /4 W d a 1.00 -

!N I -

- o 5

1 /s!/ L 5 i' 'd T - 1 g O.75 -

- g y -

g

' 4 M

=

o= cv : c=c. _ z_ 1 Ll I, i E m

0.50 -

i 1 -

s 1

's b O.25-- si s  ! -

- O

<> YT O.00 ' ' ' ' ' '

=' 0'a v 6 =

0 1 2 3 4 5 TIME (103 s)

Figure 5.2.5 Core Ring 2 (node 204 209) Clad Tennperature Predicted by MELCOR for S-LOCA Base Case Sequence

SYSTEM 80+ S- LOCA (LIMESTONE-DRY CAVITY)-

i e e i i 4 2.50- . , i i 0 COR315

~

4- -

COR314 2.25 -

- su- COR313 -

COR312 2.OO -

-v-- _

3 "C m

• ~

- - O- - COR311 o m ~

o -e - COR310 w c 1.75 -

m w -

a m Q R 1.50 -

- 2 a_ 5 g _

w g 1.25 -

3 w .-i//

~ -

a

'" o 1.00 -

/ '// > __

4 ' '

- 1 E$

- ~

m

-' c3 O O'75 -

g y 6- ;; :: : o = 0 _' -

N O.50 -

-- 0 O . 2 5 ---

' ' ~ ' ^ ' ~

0.00 3 4 5 O 1 2 3

TIME (10 s)

Clad Temperatum Predicted by MELCOR for S-LOCA Base Case Sequence I Figure 5.2.6 Com Ring 3 (node 310-315) .

__ N

SYSTEM 80+ S- LOCA (LIMESTONE-DRY CAVITY)

. . -4 2.50_ . . . . . . .

t COR309 2.25 -

. . . . + . . COR308

- un - COR307 2.00 -

--v-- COR306 _ 3 *g

- - - D- - COR305 o "o -

O C- 1.75 -

-e - COR304 w

w m m

5 1.50 -

?

< 4. :

5 -

- 2 5 y & 1.25 -

lf :\ .Pt[sI \ -

/k N N  ! I f

I o 1.00 -  ! // I.

- o 5 / //

• I $

o v  ? e _ j

...jp's, m O.75 - t y m

5 t

-= 0T : a=c . A'../\

2 k \ $

" O.50 - t

\

i- \ -

w< \ \

t m 0.25- - t i, T -- O

\ \

t

' ' ' ' ' ' -' d - -

O.00 0 1 2 3 4 5 TIME (103 s)

Figure 5.2.7 Core Ring 3 (node 304-309) Clad Temperature Predicted by MELCOR for S-LOCA Base Case Sequence

.I

l i

SYSTEM 80+ S- LOCA .

(LIMESTONE-DRY CAVITY). - 4 2.50- . .

0 COR415 -

2.25 -

....+.- COR414

- st- COR413 -

g 2.OO _

--v - COR412 _ 3 "C o

"o - - - O- - COR411 -

G 1.75 -

-e - COR410 W "x Lv

?

B 1.50 s

- 2 $

g -

g'$ '

1.25 if,. , w w

4-t n w - o o 1.00 -

?

2 o

2 3 o .

=

1 -

- 3 g

0.75 - <

g '

m 0.50 (L=

- -0 O.25 --

0.OO 12 16 0 4 8 NONE TIME (103 s)

System 80+

CPEOAPHNM 3 /16 / 9 4 14:06:53 MELCOR Clad Temperature Predicted by MELCOR for S-LOCA Base Case Sequence Figure 5.2.8 Core Ring 4 (node 410-415)

.i

-en SYSTEM 80+ S- LOCA (LIMESTONE-DRY CAVITY) 2.50_ . . i i i i i - 4 0 COR409 2.25 -

....+.. COR408

- mi- COR407 .

m 2.OO -

--v-- COR406

~

3 mC x -

"a C

- - - E}- - COR405 o 1.75 -

-e - COR404

~

w isd b

I 1.50 k

g

-2

(&

n y

1.25 -

'r W

s

) ,'I o 1.00 -

j g I -

Q E$ _

' )g '

s i - 1 O g O.75 -

11 1

h E

t o= t MN O * 'r N O.50 -

< ji -

(

8k --0 O.25--

0.00 ' ' ' ' ~

T'  : i -

0 4 8 12 16 NONE TIME (103 s)

System 80+

CPEOAPHNM 3 / 16 / 9 4 14:06:53 MELCOR Figure 5.2.9 Core Ring 4 (node 404-409) Clad Temperature Predicted by MELCOR for S.LOCA Base Case Sequence

.s

SYSTEM 80+ S- LOCA (LIMESTONE-DRY CAVITY) 2.50- . . . . . . . -4 0 COR103 2.25 -

.....g... COR203

- as - COR303 m 2.OO -

__ ,-- COR403

^

m z _

-3 m w

o o G 1.75 - -

C .

w w m x R

1.50 -

. . . /-....

?

m -

-2 m w w

& 1.25 -

l }p'_ ' %.: w.~' M~ .'

y d > -

.g,,+T

, _ ._ ; W a, w r 1.OO -

in ,

D .....

w

<_s ,

- __J

' ~ ~

W O.75 -

8n I -

u o e i 7 o

" ' 0 O.50 -

0.25-- -

-0 0.00 ' ' ' ' ' '

O 10 20 30 40 NONE TIME (103 s)

System 80+

CPEOAPHNM 3 /16 / 9 4 14:06:53 MELCOR Figure 5.2.10 Core Support Plate Teruperature Predicted by MELCOR for S.LOCA Base Case Sequence

.I

SYSTEM 80+ S- LOCA (LIMESTONE-DRY CAVITY) 2.50- , , , , , , ,

- 4

-+ - RING-1 2.25 -

-+- RING-2

- us - RING-3 2.OO -

--v-- RING-4

~

7 ,

_3 C "o  : LOW-HEAD "o G 1.75 - -

C w .ii 'l C+I- w

- 1.50 -

!!!i \ 5'%

% ~~

+

m _

,8 ~ -2 m w g s' ' u w

1.25 -

[ g/el, h -

-% ,d . _

w g 1.00 -

4 1/

p

<g, ed., -

~

5 a

a p

A

> g f ,(

W ~-=~ - 1 G

W O.75 -

• l ,

W W

w Th;,tl ,', E w

a_ o,3o _ H ..

, _ a_

sf O.25-- -

-0 0.00 ' ' ' ' ' '

O 10 20 30 40 NONE TIME (103 s)

System 80+

CPEOAPHNM 3 /16 / 9 4 14:06:53 MELCOR Figure 5.2.11 Lower IIcad Inner Surface and Penetration Temperaturr Predicted by MELCOR for S-LOCA Base Case Sequence

.s I

SYSTEM 80+ S- LOCA .

(LIMESTONE-DRY CAVITY) 20 . . .

I O DOME -

18 - - - +- - UPP-PLENUM - 2.5

_ . - ge. . - CORE

-d b -

16 j [ -4 - BYPASS

-o- LOW-PLENUM g 14J c >

E -v- ANN-PLENUM

- 2.O T m

I PRESSURIZER

(

c 12 c

w w -

1.5 g 5 10 ~ M M

u u a_

7 a- 8 -

- 1.0 W O

O 6 -

4 -

.5 2 -

' ' ' ' ' ""' * ^ - =" -

.0 0

0 2 4 6 8 10 NONE TIME (103 s)

System 80+

COENDSZNM 3 /15 / 9 4 13:42:35 MELCOR Figure 5.2.12 Primary System Pressure Predicted by ,iMELCOR for S-LOCA Base Case Sequence l

4 SYSTEM 80+ S- LOCA (LIMESTONE-DRY CAVITY) 300 . . . . . . . . .

_ . _ _ . - CAVITY - 10 275 -

250 -

225- -

Ie - -8

,,,.e i m

200 -

4, C

m M

M *

'g 175 -

6 v 9

w -

2 i -

s w y

e 3

o 150 -

i i

i-

- 2 3

> o a 125 - +.

o -

! N -4 a n- 100 -

! i. -

8-o_

s .,

75 - -i N. -

+ '

i 9 - 2 50 - , i, 25 -

,i i

! i

" 'b '

O ' ' ' ' '

O O 10 20 30 40 50 TIME (103 S)

Figure 5.2.13 Water Volume in Cavity Predicted by MELCOR for S-LOCA Base Case Sequence

.s

SYSTEM 80+ S- LOCA (LIMESTONE-DRY CAVITY) i 600 . . . i i i

- - 1.2 550_ -

500 -

2

- 1.O #

E 450- -

9 25 ~

v z

g 400 -

r

.8 O

i-

~ _ -

o M

a 350 -

o S 300

.6 l0 m

o h 4

250 m o -

200 4 -

.4 w g -

a:

O o -

o 150 -

H2 M__

2E

+- co -

.2 100_ .

- - an- - co2 50 l -v- CH4

'T 0 '

i 0 ': T' 0  :

O = '

T 0 0 100 200 300 400 3

TIME (10 S)

Figure 5.2.14 In-Vessel Ilydrogen Production Predicted by MELCOR for S-LOCA Base Case Sequence

• h.

a l

a SYSTEM 80+ S- LOCA (LIMESTONE-DRY, CAVITY)

- 25 7 - -

i 6- - - - 20 i

9 C 5 - -

6 15 g g -

w m 2 2 w

o 4 - -

o o

(<

O 3-- -

- 10 E>

2 - -

- 5

, 1 -

i O AXIAL PENETRATION O ' =

o, O 100 200 300 400 TIME (103 5)

Figure 5.2.15 CCI Cavity Maximum Axial Penetration Predicted by MELCOR for S-LOCA Base Case Sequence I

- i

_ _ _ _ _ _ _ _ _ _ _ _ _ _ . _ . _ _ . . w. - -_ < ~ . _ _ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . _ _ . _ _ _ _ _ _ . _ _ . _ . .

SYSTEM 80+ S- LOCA (LIMESTONE-ORY '

CAVITY) 1.O i i a ' '

3.O O.9~ -

O.8 _

- 2.5

_ m n O.7 -

Q 5 _- 2.O 3

>- O.6- -

N W 5

o B

m w

O.5 -

- 1.5 g w ,

O _ >-

t 0.4 -

E 50 0.3- - o

_- 1.0 $

O.2 -

'5 O.1 -

o  : RADIAL PENETRATION

.O

~

100 200 300 400 O

TIME (103 s)

Figure 5.2.16 CCI Cavity Maximum Radial Penetration Predicted by MELCOR for S.LOCA Base Case Sequence

SYSTEM 80+ S- LOCA (LIMESTONE-DRY CAVITY) 55_ . . . . . . . - 120 O H2 50 -

- + - H2O '

45--

--w-- co _ - 100

_._w.- CO2 m

o n 4o -

m y -

c2 v

35 80

• 9 w

w

,. , o - w

' '- m d

a 30 -

,v '

.v 5a y -

,s ,.

- 60 y m 25 -

.- m m

w o

20 -

e e'.

o E -

,' ,-,' - 40 $

< 15 -

i ,- -

o ,- o s'+ .F - +

10_- 7 ,.e ,

,,4 -- 2O 5 ,

l

, .s V' -

t g /

O Tn*. O. . O , . O ,

O O 100 200 300 400 NONE TIME (103 S)

System 80+

CPEOAPHNM 3 /16 / 9 4 14:06:53 MELCOR Figure 5.2.17 Cavity Gases Production Predicted by MELCOR for S-LOCA Base Case Sequence

SYSTEM 80+ S- LOCA (LIMESTONE-DRY CAVITY) 1.1 . . . . . . i 1*0 - -

o -

140 O.9 -

O -

o 6 8- O.8

- 120 -

l 52 9 o v

w 0.7--

• i cr: O -- 100 E O

U$ 0 IS O O.6 - -

g a: -

- 80 o_

9 T O.5 -

o Q M O W W

E O.4- -

a _- 60 g

< e--

z M O.3_- t UPPER

--4O O 8 -

-O - LOWER O.2 f --w-- ANNULAR

~

O.1 *---------*-------- - - - - -

~ ~ ~ ~

^

- - + - - IRWST O.0 ' ' ' ' ' ' '

O O 1OO 2OO 300 400 TIME (103 s)

Figure 5.2.18 Containment Pressure Predicted by MELCOR for S-LOCA Base Case Sequence

SYSTEM 80+ S- LOCA (LIMESTONE-DRY CAVITY) 2.50-. . . . . . . . -4 i

j - - + - - IRWST(otms) 2.25 4 I

--v-- CAVITY (otms) -

Y -- e-- UPPER (otms) 2 2.OO j -- e-- ANNULAR (otms) -

C "o

C I --A-- LOWER (atms) - 3 "o l C w 1.75 -e -

w

- 7, 5

< 3 <

n:

w 1.50 -

n:

w w

l 9 - 2 w5

~

e--

1.25 1 Y

ll

- ~

e-5 l El 5 y

1.00 j ,'7 1 t)

F -

w <

z 8

,7 as W

o -3 - 1 z O.75 12 o a y, 7 s , o i 1 3 0.50 - --

g_33--_--y_- g y -xr 1 0.25-s--+-------+-------+-------+-------

- 0 0 100 200 300 400 TIME (103 s)

Figure 5.2.19 Containment Atmosphere Temperature Predicted by MELCOR for S.LOCA Base Case Sequence

SYSTEM 80+ S- .LOCA (LIMESTONE-DRY . . i CAVITY) i i e i i 1.0 . . . . i i O STEAM

---v'-- 02 O.9 -

-9 - H2

-m-- co2

$ 0.8 -

-o co

~~;< 0.7 -

z o -

V O.6 -

8- -

0.5 -

z -

9 e-0.4 o

g E O.3 -

B o o,2 o

E

~

O1 E '- ---m--------as-------_m-_._____,______ ,

O.O t * . ~ ^ " ' ' ' E"-* -"~P ~ ^-

100 150 200 2 5.0 300 350 400 0 50 NONE TIME (103 s)

System 80+

CPEOAPHNM 3 /16 / 9 4 14:06:53 MELCOR Figure 5.2.20 Gaseous Mole Fraction Distributed in Upper Compartment of Containment Predicted by MELCOR for S-LOCA Base Case Sequence

SYSTEM 80+ S- LOCA (LIMESTONE-DRY .

CAVITY) 1.0 . . . . . . . . .

O STEAM O.9 - _ . _ ,_ . - 0 2

- -9 - H2 e- ~

0.8 --m-- CO2 5 -

@ -o co 3

0.7 -

z o -

0.6 -

sc 0.5 -

z l, -

o

_ O.4 r

m Q o E O.3 -

U o 0.2 -

s

1. g ,, ,

O.1 ,_______ ,_______,_______ ______

O.O b -"- ' ~ " ' ' - ' ~" -

4"" " ? ~*" *W*~-

0 50 100 150 200 250 300 350 400 NONE TIME (103 s)

System 80+

CPEOAPHNM 3 /16 / 9 4 14:06:53 MELCOR Figure 5.2.21 Gaseous Mole Fraction Distributed in Lower Compartment of Containment Predicted by MELCOR for S-LOCA Base Case Sequence

SYSTEM 80+ S-. LOCA .

(LIMESTONE-DRY CAVITY) e i a i i i 1.O i . . i i i i C STEAM

- -v--- 02 O.9 -

-9 - H2

~

--m-- CO2

$iE w

O.8 -

-o Co g -

3 0.7 -

z o -

Tz O.6 -

z -

O.5 -

z-z 52 0.4 -

C

$ $ 0.3 -

"a -

O m 0.2 -

<X., -

O.1 s._ ,___,_______ ,_______,_______ ______

~~-'

^ ~" ~- ""* ~ ~

O.O t -

150 200 250 300 350 400 o 50 100 NONE TIME (103 s)

System 80+

14:06:53 MELCOR CPEOAPHNM 3 / 16 / 9 4 Figure 5.2.22 Gaseous Mole Fraction Distributed in Annular Compartruent of Containtnent Predicted by MELCOR for S-LOCA Base Case Sequence l

I

SYSTEM 80+ S- LOCA (LIMESTONE-DRY CAVITY) 1.O , . . . . . . . . . . . . . .

O STEAM O.9 -

_ _ ,,._ . - 0 2

- ' ' - H2

<> ~

0.8 -

--m-- co2 y -Q Co t- O.7 r

^z O.6 $> d -

,A z

g O.5 -

p > ,v -

m a 6 e < l >

E O.4 - -

U '

35 g 0.3

,z O.2 $> -

0.1 M -

---

m--------m-______.,________,____

O.O " -*-"" # 1- " " - -+ *-"' A-E -' #- F v 0 50 100 150 200 250 300 350 42_

NONE TIME (103 s)

System 80+

CPEOAPHNM 3 / 16 / 9 4 14:06:53 MELCOR Figure 5.2.23 Gaseous Mole Fraction Distributed in Cavity Predicted by MELCOR for S.LOCA Base Case Sequence

.I

SYSTEM 80+ S- LOCA (LIMESTONE-DRY CAVITY) .

- 5.0 . . . . . . . . . . . . . .

'O ^

STEAM x 4.5 -

-.-v-.- 02

- -v - H2 4.O -

- - m - -- co2 o- Co se 3.5 -

9E -

z 3.O -

Z w 2.5 -

t) g E 2.0 -

g s.-.-. .-y_.-.-.-. ._ ,.-.-. .-.-.y.-.-.-.---..,-.- -.-.-. y_.-.

__J

@ 1.5 -

n n - n n "

v v " "

1.0 -

0.5 - -

O.O C f '= '

C t '= 'C V '= '

o 'T ' = ' C ' -- '= '

C t O SO 100 150 200 250 300 350 400 l NONE l TIME (103 s) l System 80+

CPEOAPHNM 3 /16 / 9 4 14:06:53 MELCOR l

Figure 5.2.24 Gaseous Mole Fraction Distributed in IRWST Predicted by MELCOR for S-LOCA Base Case Sequence l

s SYSTEM 80+ M- LOCA (LIMESTONE-DRY CAVITY) 16 i . . . . . i i i t DOME j4

-+- UPP-PLENUM _

= CORE

---v--- BYPASS 7 12 -

--es- LOW-PLENUM g - -m - ANN-PLENUM w

-8 w

-e- PRESSURIZER _

> 10 I w I g

A 1 A A A A A v v v v g v w 8 r

't T m

g g ...d3 .. ............. .............+..............i...............i.......

3 --!

o 6 i

IIkI I -

w I I\

m i:t - s 8 4 - ^ -

515 2 9,P Y.e sv s %

s

=

/I v= = =  ;-

'1 ' -i *es{ m 9 _____,_ __ _ _ m _ _ _

' ' ' ' ' -*-"~-- * ' - - - '

O O 2 4 6 8 10 NONE TIME (103 s)

System 80+

BWEKBRJNM 2/23/94 10:20:06 MELCOR Figure 5.3.1 Vessel Collapsed Liquid Level Predicted by MELCOR for M-LOCA Base Case Sequence

SYSTEM 80+ M- LOCA (LIMESTONE-DRY CAVITY) 20 . . . . . . . . .

t DOME 18 -

--+-- UPP-PLENUM 2.5

- - m- - CORE 16 4 - ,a - BYPASS fl - o -- LOW-PLENUM g 14 ' - v ANN-PLENUM 2.O W

=

o i i  : PRESSURIZER M o

c 12 o -

C E J i 1*5 E a

5 10 - - -

e C

oc C

" ' ' ce 8 - A M -

- 1.0 W O 6 - -

O 4 -

.5 i

2 - -

1 0 ' ' "

^

• • 2" = i - .O O 2 4 6 8 10 NONE TIME (103 s)

System 80+

BWEKBRJNM 2/23/94 10:20:06 MELCOR Figure 5.3.2 Primary System Pressure Predicted by MELCOR for M-LOCA Base Case Sequence t

i l

.i 60 SYSTEM 80+ M-. LOCA (LIMESTONE-DRY CAVITY)

SIT-1 -2.O 55 - -

-+- SIT-2 50 - --m-- lit-3 -

....y... SIT-4 45 -

m n

- 15 m n 9

40 -

, r o_

W D

35 - -

[:s o'

> 50 -

n -

D a

- 1.0 o >

a o

o 25 - -

a o- < > o g o e t-- 20 - - o-m u e 15 _ -

.5 r

10 - <> -

5 - i s -

i_' ' '. _ . _.

0 -- ' ' - - ' ' "

.O O 1 2 3 4 5 NONE TIME (103 s)

System 80+

BWE <BRJNM 2/23/94 10:20:06 MELCOR Figure 5.3.3 SIT Liquid Volume Predicted by MELCOR for M-LOCA Base Case Sequence

.I

SYSTEM 80+ M-. LOCA. (LIMESTONE-DRY . .

CAVITY)

. . - 4 2.50_ . .

i 0 COR115

~

COR114 2.25 - .... ..

us- COR113

--v-- COR112 m m 2.OO -

_ 3 u_

x m

- - E}- - COR111 "a

O c 1.75 -I - -e - COR110 w

w 4 m m

1.50  %

5 5 h - 2 wI 5

w p -

e gw 1.25 s ig w

t7 - o o 1.OO -.

J J

< ,l m o

_s o _ , ;l -

- 1 n

.-, O.75 o o -a d Z EE e & -

" O.50 -

1 id 9 - - O O.25 --

t1 T ': 0 t: -;.' =0' C i. =O C ' ;T  !: 0 i: :.

0.00 5 O 1 2 3 4 3

TIME (10 s)

Figure 5.3.4 Core Ring 1 (node 110-115) Clad Temperature Predicted by MELCOR for M-LOCA Base Case Sequence 1

l

" l ll

[

'N

SYSTEM 80+ M- LOCA (LIMESTONE-DRY CAVITY) 2.50- . . . . . . . . . - 4 t COR109 2.25 -

. . . . + . . COR108

- un - COR107 m 2.OO -

--v-- COR106 m

x - _ 3

• u_

m - - E}- - - COR105 a c 1.75 -

l _ -e - CORto4 O

4 M T e E D

7 1.50 ,ij ,

g' j y

m -

<. - 2 mw w or e, i e

• g w

1.25 , , ,- -

i a

w s

- i p . ~ . g. , _! g H o 1.00  ; i o

__.s I

P l

4

__s o _

t i - 1 o O.75 ' i - --

o

) o 0 i-E n I E O.50 bo 'V ~ ~ ~ a+..

h

'r 11 0.25 -- O t

O.OO  :: 0'7 : '

=? k - f d 0; c' : '= 0: 6: ' = ;

O 2 4 6 8 10 TIME (103 s)

Figure 5.3.5 Core Ring 1 (node 104-109) Clad Tenuperature Predicted by MELCOR for M-LOLA Base Case Sequence

.i

4 SYSTEM 80+ M- LOCA (LIMESTONE-DRY CAVITY) _4 2.50- , , , , , , , , ,

O COR215 2.25 - -

4- -

COR214 us- COR213 2*OO -

--V-- COR212 - 3 w m

2 m

- - D- - COR211 o -

C 1.75 -

-e - COR210 w

"m & _

5 R 1.50 -

Q g

w 3

- 2 m" n_

JE 9g 1.25 -

g w 4>

, t--

" _ a q 1.00 -

-' c) C$

~ - I O.75 m - -r c'd {E 2; id <e isE

" O.50 - in

[]

O.25- - ,r

-- 0 0.OO "t 0 c ' T d = c ci 7 ': = cc y'  : -3 ; c 'y 0 1 2 3 4 5 TIME (103 s)

Figure 5.3.6 Core Ring 2 (node 210 215) Clad Temperature Predicted by MELCOR for M-LOCA Base Case Sequence i

SYSTEM 80+ M- LOCA (LIMESTONE-DRY C. AVITY) 2.50_ . , , , . . . . - 4 ,

t COR209 2.25 -

. . . . + . . COR208

~

su - COR207 2.OO -

d, --v-- COR206

~

3 "g "a ,e ! I

- - E}- - COR205 O

O C 1.75 -

! - -e - COR204

~

w i  ! 5. w m i i T m R

1.50 -

j.

@. i.l

?

g -

,  ; g - 2 $

% 1.25 -

' , / !T

'S W !r / ,di f

W l

g 1.OO .

%- 6 l* i'I -

g a

o

\'l

! a u

~ 1 i _ j m 0.75 d E! i h -

m G is 'l!

d;t!

i I

i il 6 E tu i dj E

" O.50 -

g. gi ji - "

7 'I O.25-- is b

--O O.00 ' ' ^ ' ** ^' '- ' ' ^

O 2 4 6 8 10 TIME (103 s)

Figure 5.3.7 Core Ring 2 (node 204-209) Clad Temperature Predicted by MELCOR for M-LOCA Base Case Sequence

.t

2.50- SYSTEM 80+ M- LOCA (LIMESTONE-DRY CAVITY)

-4 .

t COR315 2.25 -

COR314 EB - COR313 g 2.OO -

--v-- COR312

_ 3 p "o - - O- - COR311 "o C- 1.75 -

- -e - COR310 O

w i w a: i a R

1.50 -

e .M .t -

R f.*b g '.

7,'

,, i.

\ ct -

- 2 $

g e

w 1.25 -

P 4. s , ,

w o 1.00 - o 1d +

4 - o

-J ,

a o _

! c _ j u en 0.75 -

ij , ,

m

1. k Ill h 0.50 -

<> i - o:

i r l 0.25-- [3 -

- 0 o

l O.00 '

0' 'in :0 a e =

': . c' : =' ::.'c :

0 1 2 3 4 5 l

TIME (103 s) l Figure 5.3.8 . Core Ring 3 (node 310-315) Clad Tenuperature Predicted by MELCOR for M-LOCA Base Case Sequence 1

2.50- SYSTEM .

80+.

M-. LOCA. (LIMESTONE-DRY CAVITY)

. . - 4 0 COR309 2.25 -

. . . . + . . COR308

- us - COR307 g 2.00 4

,, --v-- COR306 3 g f,j "a - -o- - COR305 "

O C 1.75 -

O

- -e - COR304 e 88 e R

1.50 -

l ,

[: I.i O

5 -

j ii i

- 2 5 sW e 1.25 -

.i l .d -

g o

t jl' /t W 1.00 -

/ I o 5

0 f..k ! lI .i O 5

m

O P. 0.75 [jg p; g 1;u -

- 1 Z

e (Lle. .8 9 9, o

Wl . D <[st #

E O.50 - ' Z

/ 2

'~/ '

e-. s O.25-- [8' i

{ -- 0 0.00 ' #' ^ ^' " " '~ '" ' -

0 2 4 6 8 10 3

TIME (10 s)

Figure 5.3.9 Core Ring 3 (node 304-309) Clad Temperature Predicted by MELCOR for M-LOCA Base Case Sequence

.I

l SYSTEM 80+ M- LOCA (LIMESTONE-DRY CAVITY) i >

4 2.50- , i i i i i i t COR415 .

2.25 -

.....g... COR414

- un- COR413 ~

m 2.OO -

--w-- COR412 3 mC x -

52 "a - - D- - COR411 -

C 1.75 -

-e - COR410 is!

w 0

= -

".-_- 1.50 - Q

- 2 mm M

w a_

s 1.25 -

w .#

1 "

gWo 1.00 - .

~

4 a

< g

• u ., , , P o o

s iy

- 1 i ~

O.75 . /5 "i ir .

s o

g , s=

z

~

t ,

5 0.50 - '/ c1 4 >

9 o

--O 0.25 --

is

'd 0= 6 = ' o C =' : =' o1 : 6 o 0.OO 10 O 2 4 6 8 3

TIME (10 s)

Figure 5.3.10 Core Ring 4 (node 410-415) Clad Temperature Predicted by MELCOR for M-LOCA Base Case Sequence

.t

2.50- SYSTEM 80+ M- LOCA ,

(LIMESTONE-DRY CAVITY)

. . . - 4 0 COR409 2.25 -

....+.. COR408 -

- us - COR407 g 2.OO -

--v-- COR406 ~

_3 C "a - - E}- - COR405 "o C 1.75 -

- -e - COR404 -

w iT w a:

jl ei n:

P- 1.50 -

e ' -

3 4 8 8 4

6 -

4 i

~

b

- h 1.25 -

/s,sgj ,

l -

8 W f .a e' '

W o 1.00 '

./

4, If e - o

/ i >< /** 4, u . i h / 0, o g 0.75  ;

, - 1 l t  ! -

6 o d  ! t['1 5

25 t . or . is /

Q:

O.50 z_

.-' I 1 p'4 '/._. / h d.

0.25-- ** -

-O

[]

O.00 ' ' "'-^ ' ' - ^ ' - '- ^ '-

0 2 4 6 8 10 3

TIME (10 s)

Figure 5.3.11 Core Ring 4 (node 404-409) Clad Teinperature Predicted by MELCOR for M.LOCA Base Case Sequence

.I

SYSTEM 80+ M- LOCA (LIMESTONE-DRY. CAVITY) ,

2.50- . . . . . . - 4 0 COR103 2.25 -

....+.. cOR203

-m- COR303 g 2.00 ,

--v-- COR403

_ 3 g m m o o C 1.75 - -

C w

m /,.;" -,'M.T ~9: 4 s s w

=

a 1.5o - i it,f E

6' d> . g" ,N'

- 2 5 S & 1.25 -

7, ~4 -

y u ..,',_M,. .?+m y

y W<

1.00 -

, W d 0.75 -

5 < >

- 1 d w  :: w m . m o s o

" U O.50 Q -

d> -- 0 O.25- -

0.00 '

0 'O 4 0 10 20 30 40 3

TIME (10 s)

Figure 5.3.12 Core Support Plate Temperature Predicted by MELCOR Base Case Sequence

.f

-~

- -~- - - - - - - - -

~ - - - - -

-- - i i

'2.50- SYSTEM 80+ M- LOCA (LIMESTONE-DRY CAVITY)

. - 4

....+.. RING-1 2.25 -

- +- RING-2 un - RING-3 2.OO -

--v--

~

7 ,

RING-4

_ 3 g "o  : LOW-HEAD "o C 1.75 -

C W (5, ' W R 1.50 -

3, 3

4 <

r l . %' s ,

- 2 5 g n 1.25 - l

,l?

~ -

S W  % +' %s W v- _

z 1,oo i n' '

z

.g r

u ,D~.T.4, .q, 5 _ g

< - , .%_N - -

1 4 W O.75 - ~ L -

W W

w W

w a- O.50 " - a_

0.25 -- -- 0 0.00 '

O 10 20 30 40 TIME (103 s)

Figure 5.3.13 Lower IIead Inner Surface and Penetration Teniperatures Predicted by MELCOR Base Case Sequence

.I

_ _ _ _ . _ _ _ _ - _ _ - _ _ . _ _ _ _ . - - - - _ . . - _ _ _ _m_ _r -

____.____-._.--______m__._____

SYSTEM 80+ M- LOCA (LIMESTONE-DRY CAVITY) 450 . . .. . m . ..

j v v v 400 .- .

350 800 g -

g E d 5 300 -

5 m

600 5 g 250 o m 3 -

l ;g a m

$ 200 -

O Q

e

- 400 eQ w 150  :> -

m m o m o o 25 o 1OO_ O TOTAL H2 -- 200

--+-- TOTAL CO 50< h --v-- TOTAL CO2 -

--w- TOTAL CH4 O T' T 5 t f0 ' - -

'T 0' v '

T t O O 50 100 150 200 250.

3 TIME (10 S)

Figure 5.3.14 In-Vessel Ilydrogen Production by MELCOR for M-LOCA Base Case Sequence

.I~

l l

l_ _ . . _ _. ._ _ ___ .-- _ - _ _ _ - _ _ _ - - - - _ - - _ - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - --

m s

4 SYSTEM 80+ M- LOCA (LIMESTONE-DRY CAVITY) 750 . . . . . . . . ,

700_- -

- 100 650 -

1

, g 600 -

c' om "a 550- -

- 80 m v

C w 500 - -

g

=>

cn M

450 - -

$w

- 60 ;g gM t.n 400 - _ _

s-- '

- 350 - -

5s 5

s 300

-r

- E E -

- g - 40 5 5 250 - 8 t UPPER

- z O

z l o r o

o 200 r -O - LOWER -

--w-- ANNULAR 150 -r ,

_._o.- CAVITY

- 20 100 f________.e______+_____ - - e- - IRWST -

50 ' ' ' ' '

O 50 100 150 200 250 TIME (103 s)

Figure 5.3.15 Containment Pressure Predicted by MELCOR Base Case Sequence

.t s .- - ,- ,, ~

1.7 SYSTEM .

80+

M-. LOCA.

(LIMESTONE-DRY CAVITY)

~

--+-- IRWST(atms)

- i -

v i --v-- CAVITY (otms) 1*5 -

i -

i -- s-- UPPER (atms) m Q -

h

--e-- ANNULAR (otms) -

C e --A--

- 2.0 m v 13 -

LOWER (otms) g p _

v W

o

- 1 i -

M 6- 1 a

< 11- - i 3.-

x v -- 1.5 x W

s -

W LaJ I 2

- t- ', w o O*9 - '

m s.- a -

z y -

N z a

- 1.O y

• - 07 - a z n -

s-o ,

z o sk o u

0.5 - , (%~ __f-_______,________y_____ -

~

.5 cs f.~ gs =sys =entesssss&"s""""e t**-

O.3 "--+--'--r+'--T-+r--,---+--<-

0 50 100 150 200 250 TIME (103 s)

Figure 5.3.16 Containment Atmosphere Teniperature Predicted by MELCOR for M.LOCA Base Case Sequence .-

.I

_.-___ _ ___ ___m

SYSTEM 80+ M- LOCA (LIMESTONE-DRY . .

CAVITY)

. . . . i i i i

o ^

7 - STEAM -

X _ . _ ,_ . - 0 2 ,

- -v - H2

+

z 6 -

- - as- - CO2 a

_ O CO _

M 5 5 o

o _

l a-5 4 -

• - o -

z

- o 3 - -

o p 4 o y _ _

w a

2< >

o _ _

'2 1 ' ,T~.' -

_ _ -a _ -e

_" , - __4 __ __ =.: -.:o_w . w --- _

O t:- ( _ 9 _ - - ' - - as - - -' - - - - -e. - ' - I T -E

' ' ' * * " ~.6_ '

O 50 100 150 200 250 TIME (103 S)

Figure 5.3.17 Gaseous Mole Fraction Distributed in Upper Compartment of Containment Predicted by MELCOR for M-LOCA Base Case Sequence

.i

SYSTEM 80+ M- LOCA (LIMESTONE-DRY CAVITY) ,

To O STEAM -

- 7 -

_ . _ ,- - 0 2 _

- -9 - H2

~

s - - as - - CO2 z

g 6 << >> -o-co -

z -

z 5 -

o -

o

• i -

3: <

o >

a 4 -

z_ -

~

o z co o_ 3 -

- o o

cr -

2 -

g -

o -

s -

I f _h --o

- -O- - - -

-e - -

, _ _- e_ = ,% -.- - v.e - -. .,-

p{y__ _ _ _ _ _ _ m

' ~ ' ' '

- - - ,- -m- - - - - ; - a - ,- - T - .-

O 200 250 O 50 100 150 3

TIME (10 S)

Figure 5.3.18 Gaseous Mole Fraction Distributed in Lower Compartment of Ccatamment Predicted by MELCOR for M-LOCA Base Case Sequence n

.u.

SYSTEM 80+ M- LOCA (LIMESTONE-DRY . .

CAVITY)

. i

. . . . i

'_ 7 _

O STEAM- -

x _._ ,_.- 02 -

- -e . H2 t-z 6 -

--m-- CO2

• D- CO. -

z _

~~< -

"z 5 -

o o _

I z

• 4 -

Ez 3 -

o__

o <

& 2 -

S o _

2 . . _

.%*p.y_-- o--

1<>

-o- _ _._ g -

r-= A- v-- v---

M _ _ 'v-_---m-------_' .-------m----

_ % , , _ _ , , %T ~-6-'

O t K _ '_ ' ' '

O 50 100 150 200 250 TIME (103 S) l l Figure 5.3.19 Gaseous Mole Fraction Distributed in Annular Compartment of Containment l Predicted by MELCOR for M-LOCA Base Case Sequence l

.i

. . _ _ _ _ _ __ . - _ _ . . _ _ - _ _ _ _ . _ . _ _ _ _ _ - . - _ . _ _ . _ _ _ - . - ___J--_ - - - - - --c.- - t _ _ . _ _ - . . --. - - _ - - _-

I SYSTEM 80+ M- LOCA (LIMESTONE-DRY ' ' ' CAVITY)

, - 9 . i i i o O STEAM

~ -

_ . _ ,- . - 0 2 X

8 -

-+- H2 o

__m- CO2 _

7 -

a co 5 6 -

< O o

25 5< >

z C 52 e-o o 4 4 >

cr

j. 3<1 0

1 _

2 -

3 <gc , ,

r .~. y . g ,____ -o -

--o -

_e _

7

_ '__-_m_T,_T__~_" "._T, ___T,-i.7-T C -y S % C T1~2 50 100 150 200 250 O

3 TIME (10 S)

Figure 5.3.20 Gaseous Mole Fraction Distributed in Cavity Predicted by MELCOR for M-LOCA Base Case Sequence

.f r

T SYSTEM 80+ M- LOCA (LIMESTONE-DRY CAVITY)

- 2.0 , , , , , , , , ,

'o ^

STEAM

- 6, x 1.8 3----,--.-.-.-.-,-.-.---.v.-.-.-.-.-,- _._ ,_.- o2

- -v - H2 1.6- - --m-- CO2

-o co Di 1.4 -

se 9E -

z_

1.2 -

z O O O O O

- 1.O -[ -

o O E O.8 -

u.i

__a 3

0.6 -

0.4< > -

0.2 -

O.O C v

= 'a v '

= b '= ti v '= c' - e i O 50 100 150 200 250 3

TIME (10 S)

Figure 5.3.21 Gaseous Mole Fraction Distributed in IRWST Predicted by MELCOR for M-LOCA Base Case Sequence

.1

_ _ _ _ - - - _ _ _ - . _ _ _ .  % '-'"t lW

d* "' w e -

C' __ m____________.-__.-____m_.._____ m___._

SYSTEM 80+ M- LOCA (LIMESTONE-DRY CAVITY) g 2.75 i . . . . . . . ,

2.50 - -

i _

j - 8 2.25 - -i _

2.00 -

i.

m.

~

1.75 -

_ - 6 { .

ce  : >_

" 5 w 1.50 -

i.

- 2 w

g o  : s

• W -

o w

o 1.25_ -  : -

-4 o 3 3 s__  : >_

> 1.00 -

o <

0.75 -

- 2 0.50 -

j _  ;

i O.25 ,  :

AXIAL PF"FTRATION _

i - - - 24 Houl; ,

j . - -. .

0.00 ' . . . .

O ,

O 50 100 150 200 250 TIME (103 S)

Figure 5.3.22. CCI Cavity Maximum Axial Penetration by MELCOR for M-LOCA Base Case Sequence

.s L

r -m, ,w - -,e,--

s SYSTEM 80+.M- LOCA (LIMESTONE-DRY CAVITY) 5 5 5 .I _

3 ' -' ' '-

~

7 -

i -

6--  ! -

2.O m

s

~

i

~

m T 5 -

3 -

[

52 v

v 3 -- 1.5 >_

>- cr

- 5w 4 -

9 5

- w 2

C 2 o -

O w

w c) 3-- i -

- 1.O >-

>  : e i b  : >

l > -

o i 2 -

3 -

l i -- .5

~

RADIAL PENETRATION 24 HOURS -

O ' ' ' ' ' '

.O O 50 100 150 200 250 TIME (103 S)

Figure 5.3.23 CCI Cavity Maximum Radial Penetration Predicted by MELCOR for M.LOCA Base Case Sequence

w 1

SYSTEM 80+ M- LOCA (LIMESTONE-DRY CAVITY) .

32.5_ . . . . . . . .

- 70 30.0 -

k 27.5 -- ,- - - 60 w -

m 25.O . -

i

, m cn o

m[ 2 2 . 5 - -

,',' -- 50 m v

C y 20.O -

,e w

w E - ,

- 40 wN w 17.5 -

d d x

',,..-.s i

- x 15.O -

g _ ,",' * -

- 3o OQ o 12.5 -

i

~-

R 10.O -

o l

.*.W- - 2O R

~

7.5 -[ '

, .# ' , C

-+- H2O H2 5.O-- ,s' ,-

- 10

,- -+- --w-- Co 2.5 8

,.# -+~~ _._w.- co2 vi *,c ' c' '

O.O '" " ' ' ' '

O O SO 100 150 200 250 TIME (103 S)

Figure 5.3.24 Cavity Gases Production Predicted by MELCOR for M.LOCA Base Case Sequence I

, y

e . .

+

10 SYSTEM..

80+

2-. SGTR .

(LIMESTONE-ORY CAVITY)

- 1.4

. - SG-A 9 -

j --+-- SG-B

, _i ---

VB at 11674 sec - 1.2 8 -

yr -

o 7_ -

l> -

- 1om un 9

3

[o v 6 - -

8 C w -

il - . 8 g

$ 5 -

il< -

$  % M

=

E 4-- I: 's -

.6 Ei o-u id  : ~

s y, o  : -+. o m 3 -

- - - - + - - ------+--------+= m-

.4 i -

0 2 -

i -

.2 1 -

i -

0 ' ' ' ' ' '

.O O 20 40 60 80 100 NONE 3 TIME (10 S)

System 80+

OABOCGTNM 2/27/ 14:25:34 MELCOR Figure 5.4.1 Steam Generators Pressure Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence

.I

SYSTEM 80+ :2- SGTR (LIMESTONE-DRY CAVITY) n - 7 200- i i i i i i i i

DOWNCOMER 180 -

....+.. EVAPORATOR

- 6

- - as- ECONOMlZER Q

160 - --v-- BOILER E

C

-- 5 *o E 140-\P v w 123 2

3 120 -y

~ 4 3 S

's ' Y d j -

o

• 100 -

's _s o

o s

- 3 o n- _ i - -

80 - '

- 4 g i V 4 o i a

<n s -

y 60_- g - 2 (n 5 \ -

2 40 - s Y _ 1

\ -

20 -

4 -usy -':-. 9 . . :-se . _ , , ' ' ?- - ----- . e _ . . .

~'

T' '

O O

O 20 40 60 80 100 NONE TIME (103 S)

System 80+

OABOCGTNM 2/27 / 14:25:34 MELCOR Figure 5.4.2 Secondary Side Water Voluine of the Broken Steam Generator Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence

.t l

200- SYSTEM .

80+

2-. SGTR .

(LIMESTONE-DRY CAVITY)

. . - 7

DOWNCOMER 180 -

....+.- ~

~

EVAPORATOR

-m- ECONOMlZER - 6 160 -

--w-- BOILER E 'Q

,2 I--

14o -_ -- 5 *a w C 2

3 o

120 L -

y 2

> -p - 4 o3 i

g o

1OO j - #

i i

d 3 oo-cn 80 -i I

1 o t CD

, (n i i

3 y 60_  ; -

d 2 v)

\ E 40 -i - N t ,

y - 1 20 i -

, . _4 -a ,- . . % . g . .- . . + . . + . .- . . +, . . as, .

O T 9 '

'T ' '

T

- 0 0 20 40 60 80 100 NONE TIME (103 S)

System 80+

OABOCGTNM 2/27/ 14:25:34 MELCOR Figure 5.4.3 Secondary Side Volume of the Unbroken Steain Generator Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence I

SYSTEM 80+ :2, SGTR (LIMESTONE-DRY CAVITY) 2O i i i i ..

. . i i i i

^

DOME 18 -

j - - + - - UPP-PL' ~

3 --m-- CORE

~

16 -

[ -+- BYPASS

~

- [] LOW-PLENUM 5 14 -

[ --4 - ANN-PLENUM g 3 -

VB of 11674 see y 12 -

U \ i o 10 -

i.

w &

y 8 l

0 2

0 0 0 m a -

s.

g _ , ,

/

s._ _._._+._ ._._._. ._._._.-._..i.-._._._._._ -.-._.

o

> 6 -

J'% j -

m 1N  :

4 -

( 3 e_ ___N :u_

2 -

g , , ,

' ' ' ' ' -"- " " --* - ' " '- ~

O O 5 10 15 20 25 30 NONE 3 TIME (10 S)

System 80+

OABOCGTNM 2/27/ 14:25:34 MELCOR Figur e 5.4.4 Vessel Collapsed Liquid Predicted by MELCOR for the 2-tuhes SGTR (case 1) Base Case Sequence

.I

c. -

SYSTEM 80+ :2- SGTR (LIMESTONE-DRY CAVITY) 20 . . . . .. . . . . . .

^

DOME 18 -

i --+-- UPP-PLENUM

- 2.5~

II

- - - m- - - CORE 16 i k 3b

_ . * - BYPASS f 9 15

-O- LOW-PLENUM g 14 - -

if -v- ANN-PLENUM

- 2.O T

= l l Jf PRESSURIZER o o ,

c 12 i t 5> ........

va at 11674 see G

w w x ~ i i t -

1~5 "

5 10 -

M 0

x w:- i, 0x o-o- 8 -

jt -

~

o e -

i - 1.o e O 6 -

31 O

4 -

3

.5 2 -

i -

' ' ' ' ' C -

0 ' ' -

.O O 5 10 15 20 25 30 NONE TIME (103 s)

System 80+

OABOCGTNM 2/27/ 14:25:34 MELCOR Figure 5.4.5 Priinaiy Systern Pressure Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence

SYSTEM 80+ , :2- SGTR (LIMESTONE-DRY CAVITY) 2.50_ , , , , , . - 4 O COR115 2.25 -

....+.. COR114

- un - COR113 m 2.OO -

--v-- COR112 m

x _ - 3

• u_

m - - E3- - COR111 l a c 1.75 -

_ _e - COR110 O

w w a: oc

R 1.50 - -

R

< - 2 a:

a: -

+. w w

g 1.25 -

g w

w >

l -- 4'l l - H C o 1.00 -  ! -

o o <  : !' . <

_a - J o -

4 - 1 o

- 0.75 -

o  : o E  ?? = : 5 -? Y E 0.50 -

I -

i-O.25-- 1

--O o

0.00 ' ' ' N' - - ' " -

o 5 10 15 20 TIME (103 s)

Figure 5.4.6 Core Ring 1 (node 110115) Clad Tennperature Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence 1

2.50- SYSTEM 80+ :2- SGTR (LIMESTONE-DRY CAVITY)

, i i . . i i - 4 t COR109 2.25 -

COR108 us - COR107 m 2.OO -

--v-- COR106 m

x -

< > _ 3 'm I

c 1.75

- - D- - COR105 "a g  ! -e - COR104

~

O k;

y l N R

1.50 - d '

il 1 hi!

ii!

R<

l, i ! - 2 g

$ -> i g 1.25 -

s'i  ! -

i m -

e ,i . w n~

~o 1.00 -

l@I !

T "

o a n i y ,4 <

an a

o _

<> l.  ! - 1 o

= 0.75 -

sl -

=

o a re ; _- - 0=y.- 4Er ol! 8 o

" 3= E O.50 -

I i

is O.25--

• Il --O 8

i I.

O.00 ' ' ' " '

=_i O 5 10 15 20 TIME (103 s)

Figure 5.4.7 Core Ring 1 (node 104-109) Clad Temperature Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence 1

i 2.50-SYSTEM 80+ :2- SGTR (LIMESTONE-DRY. CAVITY)

. . . . . . - 4 t COR215 2.25 -

COR214

-m- COR213 m 2.00 -

--v-- COR212

~

^

x .

- 3 u.

"o - - E}- - COR211 "o O 1.75 -

_e - COR210 O

w w m x 5

1.50 - -

R g -

- 2 5 9 1.25 -

n W ,

i W M o

< 1.00 - -

r

- o

.s ,1 a o .

- i s - 1 o g 0.75 -

g o o z_

' = ' = cv : m-o z_

0.50 -

r O.25-- 3'

--0 4b 0.00 '

"! T =5o  :'T =cc :

0 5 10 15 20 TIME (103 s)

Figure 5.4.8 Core Ring 2 (node 210-215) Clad Temperature Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence

.I

2.50.

SYSTEM 80+ :2- SGTR (LIMESTONE-DRY. CAVITY)

. . . , , . - 4 0 COR209 2.25 -

. . . . + . . COR208 mi - COR207 g 2.00

- ~

--v-- COR206 g

_3 "a - - D- - COR205 "a C 1.75 -

-*- COR204 O

N N R

1.50 - -

R s -

- 2 5 s 1.25 -

4 -

W W

[;f a 1.00 - - o a .; a o <- _ j u m 0.75

- 9 l  ! -

m 5 a N & 6 a e = 0 2.  :

m---- -- E p}

o: 0.50 - 9 - N

< > 11 i

O.25-- --0 I l 7 0.00 '

x,

O ^'x: 4: : ';.: c 0 5 10 15 20 TIME (103 s)

Figure 5.4.9 Core Ring 2 (node 204-209) Clad Temperature Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence

.I

2.50_ SYSTEM 80+ ,:2- SGTR (LIMESTONE-DRY CAVITY)

-4 1 t COR315 2.25 -

. . . . .e- -

COR314 l un - COR313 l

m 2.00 -

--v-- COR312 m

~

,3 g G

o 1.75 -

- -a- - COR311 "o

- -e - COR310 w

a: m" R 1.50 - -

a

$ Q m

w

-2 m a_

w 1.25 - -

E W

o 1.00 S

'g 5 a

3 e - 1 "

m--

O.75 -

0

.9 o

e= cv : c4 O'- ' '

" O.50 -

- s 11 0.25-- <> -- O O.00 ' '

= ' 0 0: '= 00:

O 5 10 15 20 3

TIME (10 s)

Figure 5.4.10 Core Ring 3 (node 310-315) Clad Temperature Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence

.t

SYSTEM 80+' :2- SGTR (LIMESTONE-DRY CAVITY) -4 2.50- , , , , , . .

t COR309 2.25 -

. . . . + . . COR308 un - COR307 m 2.OO -

--v-- COR306 - 3

^

u-x -

"a - - D- - COR305 "a C 1.75 -*- COR304 O

w + w m

m 5 1.50 - fi -

R

- 2 mw m _

w  :-

% 1.25 -

!? -

n W -

7. 1:

/

W c 1.00 - ,/ o< i - o V 3 V'e }! ; 1 3 o

o _

t

_ j m O.75 - N> - -

m 6

2 =;n : y= 0= .m

}f,s &. 5 z__

z__

'2:

O.50 -

r

- '2:

i.i i li O.25-- 6 - --O

'e

' c 0.00 ' i '

- 'O i  ;:

0 5 10 15 20 3

l TIME (10 s)

Figure 5.4.11 Core Ring 3 (node 304-309) Clad Temperature Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence l

l .E l

f l

l

~

SYSTEM 80+ :2- SGTR (LIMESTONE-DRY

. . . CAVITY)

. - 4 2.50_ . . .

t COR415

~

2.25 - .....s... COR414 es - COR413 2.OO - --v-- COR412 ~ _ 3 "g

- - O- - - COR411 O "a -e - COR410 C 1.75 -

w x

w m -

3 5

1.50 -

- 2 5 i

g -

sw 1.25 -

1 w

~

s-- ,4

' - o o 1.00 <

3 J

• < o J

u . -'p' l

- 3

• O.75 -

.4 4 5 6

6 _ . E m a=  : : :2- -

" O.50 -

II

--O O.25- - ,,

ii

': '= ; .O '  : dcO O.00 20 O 5 10 15 TIME (103 s)

Figure 5.4.12 Core Ring 4 (node 410-415) Clad Temperature Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence

.I

.w SYSTEM 80+ :2- SGTR (LIMESTONE-DRY CAVITY)

. - 4 2.50_ i . . . . .

0 COR409

~

2.25 -

....+.- COR408 m- COR407

~

2.00 -

--v-- COR406 _3 g 7

m

- - E}- - COR405 "g g -

C 1.75 -

- -e - COR404 w

w

• m cr R 1.50 - s 3

5 _

fl - 2 5 w

w sw 1.25 -

i i.

l w

H l-Q Q 1.00 -

7 i'

_.a t

U o

n 0.75 4 -

[>f-

- 1 O 5

3 g- = ;= : c a 0=  : cre-

z

g; "

" O.50 -

4 0.25-- --O O.00 ' '

t;'O T : '

= 20 d v :

O 5 10 15 20 TIME (103 s)

Figure 5.4.13 Core Ring 4 (node 404-409) Clad Temperature Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence

.t

=

SYSTEM 80+ :2- SGTR '

(LIMESTONE-DRY

' CAVITY) _

2.50- i i COR103 t ~

.....e... COR203 2.25 -

sm - COR303 ~

-v-- COR403 _ 3 mC 2.00 -

2 52 o "

c 1.75 -

g i

w cm

< i

,. , _. _. . . .,. ..;. . . . M.,. ,. g -a _ g y

5 1.50 -

I -

- 2 cr 4

w W

< h> ':E g 1.25 -

W W Y 2

- w w 1.00 - <

G

• I v - 1 d m _, .

O.75 - *L E o

w "

cr .__: o o < -

0 0.50 -

__ O O . 2 5 - '-

i i * '

O.OO 30 40 O 10 20 3

TIME (10 s)

Figure 5.4.14 Core Support Plate Temperature Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence

.I

SYSTEM 80+ :2- SGTR (LIMESTONE-DRY CAVITY) 4 2.50_ . . . . . . . -

....+.. RING-1 2.25 -

-+- RING-2

-m- RING-3

~

2.00 -

--w-- RING-4 _ 3 "g 7 ,

O LOW-HEAD o "o O G 1.75 -

,g. -

W '\ ,

+-

-r-4 W O

O-- 1.50 -

%. =- -

s i <

< . O

,J - 2 $

& 1.25 -

j /

S W '

W z - z 1.00 -

l l 52 G

e o_

r . . e--

4 - 1 <

l W w

O.75 - -

9 W

w 5  : ;;- c.: 0 =; 5 a

1 0.50 -

O.25- - --O l O.00

! O 10 20 30 40 l

! TIME (103 s)

Figure 5.4.15 Lower llead Inner Surface and Penetration Temperature j Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence

.I I

em SYSTEM 80+ :2- SGTR (LIMESTONE-DRY CAVITY) g g 5 5 5 g B E g g 3 3 5 1

700 _

- 1.5 l

n 600 -

E-s Q

v "o

C-i i

2 O

P 500 -f -

z o

o - -

_- 1.O p o o o

l O a:

400 -

O a:

I

a. _ a.

l m m-I C o

d

< 300 -

E o <c

_ o w .. -

.5 w a: _

a:

o 200 -

o o o a ,

H2 _ g

....+.. CO l

100 -

--m-- CO2

_ v- CH4 -

O '

i ' -- O '= ' -- 'O '=' '0 '

=' fO' -

.O O 75 150 225 300 TIME (103 S) l l

Figure 5.4.16 In-Vessel Ilydrogen Production Predicted by MELCOR for the 2. tubes SGTR (case 1) Base Case Sequence

.I l

l l

850 SYSTEM 80+ :2-. SGTR (LIMESTONE-DRY CAVITY).

- 120 750 -

1[

_- - 1oo 2 650 -

Is ._

"o O

E.

W 550-- -- 80 M D cn N

w

~

~

0 cr g: 450 - -

o_

(( _- 60 g U $ d > g y 350 - -

g a

1 _ 5

- 40 z h 250 _ t UPPER _ g o --O. LOWER

--w-- ANNULAR 150_-( 8 "

_ . _o. . - C AVITY 20

- - + - - IRWST -

50 ' ' ' ' ' ' ' ' ' ' ' '

O 75 150 225 300 TIME (103 s)

Figure 5.4.17 Containment Pressure Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence

.I

SYSTEM 80+ :2- SGTR (LIMESTONE-DRY CAVITY) . .

1.7 -

- - +- - IRWST(atms) -

7 --v-- CAVITY (alms) _

- 2.5 7 -- e-- UPPER (alms) g 1.5 '

7 --O-- ANNULAR (alms)

C "o -

1

--A-- LOWER (otms) -

- 2.O O "o

1.3 7 -

w w - '

{}

h 8 -

x :f .

7 x

M 11 - -

4 , a

- 1.5 W1 1

N :5

{$

N

+- IP ) +

w z O.9 ,

c o

z ta w La_3 2

s - d > < > - - 1.O z z

R 4 > . 5 E y O.7 -

4 o

E o

o 1$

o u - 9 c 3 5

5- N

-y=-

O -

[> '--P-------

_ a _ lbav_ve-J , - ,eV----+--------+-------+--,--;--o s--mm -*e*=

O.3 0 75 150 225 300 TIME (103 s)

Figure 5.4.18 Containment Atmosphere Temperature Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence

.I

3.50 SYSTEM 80+ :2- SGTR (LIMESTONE-DRY CAVITY) 3 .'2 5 -

i -

3.00~-  ! -

10 2.75 -

i -

2.50 - -

i -

8 -

3 2.25 3

E w

2.00 -

i g

E m

1.75 - -

6 g m

o  : o C 3 1.50 -

w >-

'=

i-4 1.25 - -

. -- 4 5 4

1.00 "

O.75 -

i -

-  : - 2 0.50 -

i -

AXlAL PENETRATION O.25 - < j ........

24 HOURS -

4 0.00 ' ' ' ' ' ' ' ' '

O O 75 150 225 300 3

TIME (10 S)

Figure 5.4.19 CCI Cavity Maximum Axial Penetration Predicted by MELCOR for the 2. tubes SGTR (case 1) Base Case Sequence

.I

4 5.5 SYSTEM 80+

2- SGTR (LIMESTONE-DRY CAVITY) 5.0 -

! F -

4.5- -

! - - 1.5 m 4.O -

i -

. 5 C e

3.5 -

- 6

>-- CE g 3,o-- 3 - - 1.0 +--

m w  :- s 2 O 8

o 2.5 -

i W

2.0 - e--

G t- ,

A >  ; <

-ct

• O o 1.5- - <>

i - -

.5 1.0 -

i -

0.5 -

i-

RADIAL PENETRATION -

<> j .. --

24 HOURS l' ' '

0.0 ' ' ' ' ' ' ' ' ' '

,o O 75 150 225 300 TIME (103 S)

Figure 5.4.20 CCI Cavity Maximum Radial Penetration Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence t

i

,,- n -

SYSTEM 80+ :2- SGTR (LIMESTONE-DRY CAVITY).

,, - - 80 35 - -

x -

/

30 -

n ,

" m o

M

,/

- -- s o oam

-- a m

52 25 - - -

52 s' "

w - -

w w <4 m w 20 -

s' - w

__s .-.s La.J / .n L.a.J m -

s *-- 4U T

~ -

f .-v -

" w r

'. - m

< 15

• o

,.s o

t:

> f s' .-

' t--

< 10 -

i v - <

c_> -

e+ ,. ^

2O o I '

.- H2 _

• ,d' H2O _

5 -

e' ,- --w-- CO s ,- - 4 --

~

s ,-

,,,,-e n

-.-w.- CO2 -

e -

O

1. ~ # ' ' ' ' I ' ' '~ ' '

O O 75 150 225 300 3

TIME (10 S)

Figure 5.4.21 Cavity Gases Production Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence

.I

SYSTEM 80+ :2- SGTR , ,

(LIMESTONE-DRY CAVITY). . . .

'o O STEAM -

- 7 -

_ . - y- - 02' x _

~ - -v - H2

--m-- CO2 H

2 6 -

O CO y _

E

< o -

~

z 5 -

O o -

I -

cL cu a

4 -

E ~

M z 3 -

O i--

o -

< o cr ~

' 2 ._

u.s -

~

._O 3E T. _

1 g>

pJ, V ]-

t

_ _ m _ _ _ _ _ _ _ _m.

• 3"

, K F-

=_g_- -

g _ _ _ _ _ _ _ m __g - _ _ _ _ %_ __ _

• r,* -

• T -

---

,.------e--

• - =g - * -

• y * - V7 + = * * -

• t P * -

0 300 350 0 50 100 150 200 250 3

TIME (10 S)

Figure 5.4.22 Gaseous Mole Fraction Distributed ir) Upper Coinpartinent of Contain nent Predicted by MELCOR for the 2-tubes SGTR (case I ) Base Case Sequence i

SYSTEM 80+ :2- SGTR -(LIMESTONE-DRY CAVITY)

O STEAM T 7 _

x _ . _ ,_ . - 0 2

~

-9 - H2 6 --m-- CO2 3 -

CO a

O- -

M o

5 -

o _

l

?c o

a 4 _O -

/

- y -

n z_ _

z -

o 3 -

w ce 2 <.

'a _

o _

2 F -

1 -<

p . , . , _d.p - - m - - - - - - - -m g = - _= - q = - = % _ _ _ _

P ,

-=::T T4 . 7. T_ ,*_ . r,_T_ ; . - . ? , . r- . _T_

O _

, _ m-

- M v--tv 0 50 100 150 200 250 300 350 TIME (103 S)

Figure 5.4.23 Gaseous Mole Fraction Distributed in Lower Compartment of Contaimnent Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence 1

b i

SYSTEM 80+ :2- SGTR (LIMESTONE-DRY CAVITY)

+

'O ^

STEAM C 7 -

x -. _ , _ .-

02

~

- H2 -1 E

l 6 -

- - m-- co2 w -

O- CO -

o 5 -

0 _

I z '

e z 4 _

a; _

C" z -

52 3 -

o .

cr m

2 . ..

a o _

'2 s 1

s ci - - m - - - - - - - -o,- g _ _ - - - ~ % _=_- - e , _ __

0 -

F( _.

P2__ M&N iF r7- #-- Z T-Tv- T TC ~+-

0 50 100 150 200 250 '300 350 TIME (103 S)

Figure 5.4.24' Gaseous Mole Fraction Distributed in Annular Compartment of Containment Predicted by MELCOR for the 2-tubes SGTR (case 1) Hase Case Sequence

.I

,.,m. ~ --.

c , s v w , _ m v __ _._ _ ___

1.O SYSTEM 80+ :2- SGTR .(LIMESTONE-DRY CAVITY) i e i . . . . . . . . .

^

STEAM O.9 -8 - . - ,- - - 0 2

<> - H2 0.8 -

--m-- co2

>- o co -

O.7 -<>

o >

0.6 -

+- -

25 z

o O*5 - -

p o < /> Q>

Q E O.4 -

i.a a <>

o 0.3 -

s 0.2 e. -

O.1 -Q v -

...q---m------ g - -m-q m___g____

O.O d '

d I" " " ' * ~ ~ ' - '- - '*- +'#' T *'#'

• O 50 100 150 200 250 300 350 3

TIME (10 S)

Figure 5.4.25 Gaseous Mole Fraction Distributed in Cavity Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence I

SYSTEM 80+ :2- SGTR (LIMESTONE-DRY ' ' CAVITY) io 3.25 i i e ' ' ' '

^

STEAM _

g 3.OO - 0 -.- w - 02

<> H2 2.75 -

--m-- co2 _

2.50 -

o- co M 2.25 8 3: < > -

2.00 -

g '

z 1.75 -

o <

7 .-

-.v, > _

U 4

1.50 -

CE 8 ' 1.25 -c w

_, __-m _

o 1

1,oO /f '

i v . . . .

- v . ._ . se _ ._ --w

, - y -.- ,_.3,,

O.75 -

,- v v p -e o' ' m' _e' -

O.50 -

, e v

p

~ _ _- O_- _y

-"-W- -

O.25 -

/ff-"

O.OO 7 ( , i , , , . . . . i ' '

100 150 200 250 300 350 O 50 TIME (103 S)

Figure 5.4.26 Gascous Mole Fraction Distributed in IRWST Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence 1

i 4 . -

SYSTEM 80+ :2- SGTR (LIMESTONE-DRY CAVITY) ' " ' '

1O**

t

'l Cl-1(Xe)  :

- -+- Cl-2(CsOH) i 1 O+3

[

-m- Cl-3(Bo) (-*-----f--*  !

- -- w-- Cl-4(l) - -

+ *-- -

91O*'

v M [

- -x- - Cl-5(Te) -, . - me- - .  !

i -----O-----

Cl-6(Ru)  :

+1 r

-v- Cl-7(Mo) ' , - -- ,- K _- , _ g , i

'^-

! -O Cl-8(Ce) , --- -- o __ _ .

2  :

a --A-- Cl-9(La) lf. i c2::

w 1 O+o [ - - o- - Cl-10(U) 'gn n  !

@ E n Cl-11(Cd) L [

Q La 1O

-1 r

Cl-12(Sn) 1 i

I d  ! -la Cl-13(B) l 5

~ " --9-- Cl-16(Cst) i -

~2 5 1O i

' b i r .

I I -

10 r

~!

It

-4 .e . .a .

.a .i ..e . . .

1O +6 1 0+ 0 1 0+ 1 1 0+ 2 1 0+ 3 10+ 4 1 0+ 5 10 NONE TIME (S)

System 80+

OABOCGTNM 2/27/ 14:25:34 MELCOR Figure 5 4.27 Radionud: des Released from Fuel Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence

.t

., SYSTEM 80+ :2- SGTR (LIMESTONE-DRY CAVITY) 10 e m - - , -

n - , - , m:

O Cl-1(Xe) -

+-- Cl-2(CsOH) '

1O+3 r -m-  !

g E Cl-3(Bo) 0 E -

--v-- Cl-4(l) 7 ua m

1 O+2  :

i -

-x- - Cl-5(Te)  :

@ {

Cl-6(Ru) '

I +1 -e- Cl-7(Mo) ,'

ui 1O F z

_.2 E

o- Cl-8(Ce) {

1

- --A-- Cl-9(La) o -

+---

m 1 O+o [ - - e- - Cl-to(U) ]

Z =

Cl-11(Cd) 2 _i .......- Cl-12(Sn) ,'

10 r ~

Z E -2 Cl-13(B) -

u M  : + - - --+.  :

to g --G-- Cl-16(Cst) --

_2 y 1O r j

z E , + _ _ _ _ _ _ _o _

or -

3 . _ x_ . _ . _ . _ - _ . _ , -

_3 * - - - - - ,

1O [ c  :

in

-# ^^ ^^ ^^

10 1 O' 1 O* ' 10+2 1 O*

• 1 O* # 1 O* ' 1 O*

• TIME (S)

Figure 5.4.28 Radionuclides Released to Main Steam Line Ilouse Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence

_ _ ._a

• 8iW>.

SYSTEM 80+ :2- SGTR (LIMESTONE-DRY CAVITY) 10 4  ;

Cl-1(Xe)

, ,g+3 , +- - Cl-2(CsOH)

! - In - Cl-3(Bo)  ! -

--v-- Cl-4(l)

^

g 1 O+2 [ -

-x- - Cl-5(Te) ] '

5 C Cl-6(Ru) s . .

]

2

+1 r

*v Ct~7(MO) 7 z  !

~

o- Cl-8(Ce)  !

O -

- - *- - Cl-9(La) 5 w

10+ [

- - o- - Cl-10(U) 'I

n Cl-11(Cd) z , }

10 r Cl-12(Sn) ,

Q  ! -ca Cl-13(B)  !

2  : --O--  :

-2 Cl-16(Cst) ,

C -E 10  !  ;

-3 10 r  !

5 10 O 50 100 150 200 250 300 350 400 TIME (103 s)

System 80+

OABOCGTNM 2/27/ 14:25:34 MELCOR Figure 5.4.29 Radionuclides Released to Envirunment_ Predicted by MELCOR for the 2-tubes SGTR (case 1) Base Case Sequence t

SYSTEM 80+ :2- SGTR (LIMESTONE-WET-SPR AY )

20 . . . . . . . . . . .

t DOME 18 -

- - +- - UPP-PLENUM

~

- 2.5

. - - m- - CORE 16 3 L

- -a - BYPASS 4 P - -o -- LOW-PLENUM g 14- -

v ANN-PLENUM -- 2.O W

$ c 12 B

t g

PRESSURIZER m

c d a ' E

- 1*5 a

10 -

i . 94 F -

5 0 a t :n . O E 8 -

[ t i

- E t E -

' - 1.O M O 6 -

y ,

8 4 -

' b -

.5 2 - II -

O ' ' ' ' 't -

.O O 5 10 15 20 25 30 NONE TIME (103 s)

System 80+

BOEJAVNNM 2/27/94 09:09:25 MELCOR Figure 5.4.30 Primary System Pressure Predicted by MELCOR for the 2-tubes SGTR (case 2) Base Case Sequence

.s

i ,

SYSTEM 80+ :2- SGTR (LIMESTONE-WET-SPRAY) . . . .

16 , . . . . . .

I ^

DOME

+-- UPP-PLENUM _

14 -

= CORE

- -v- - BYPASS 12 -- e-- LOW-PLENUM 7 . _ _ x__ _

-4 - ANN-PLENUM m I e- PRESSURIZER _

w 10 -

1 W

> I - - - -

v v v

• • ........, gy -

w 8

+.1..g...............g...............g...............g.............

w . ?.

a - . .

i g 3 T' ,

vi J .

• 5 -

o 6 - -

w

" \

w m -

o 4 -

' 2.

-e- - - - - es- - s

2. 2.

2 -

4

- --x----g--- -p _.

' ' ' ' ~----"-+-~*"--'-C O

0 5 10 15 20 25 30 NONE TIME (103 s)

System 80+

BOEJAVNNM 2/27/94 09:09:25 MELCOR Figure 5.4.31 Vessel Callapsed Liquid Level Predicted by MELCOR for the 2-tubes SGTR (case 2) Base Case Sequenc

.I

SYSTEM 80+ :2- SGTR (LIMESTONE-WET-SPR AY).

2.50- . . . . . . . . . . -4 t COR115 2.25 -

.....e-.. COR114

- un - COR113

~

_ 2.OO -

--w-- COR112

_3 g m - - D- - COR111 "a 8 1.75 -

- .e - COR110 O

w IsE m . O D 1.50 -

d .

e--

r g

w p

- 2 wI g

w 1.25 -

w H ll W H

& a 1.00 -

yl > -

Q

_, .I >

o . <l - 1 o 0.75 -

l -

=

c 3 sb c) g m_ _

_ .: , J, g

• ~ "

O.50 -

15 O.25-- q) --0 0.00 '

O 5 10 15 20 25 30 1

TIME (103 s)

Figure 5.4.32 Core Ring 1 (node 110-115) Clad Temperature Predicted by MELCOR for the 2. tubes SGTR (case 2) Base Case Sequence

.I l

2.50- SYSTEM 80+ :2- SGTR (LIMESTONE-WET-SPRAY)

. . . . . . . . . . . -4 0 COR109 2.25 -

.....g... COR108 as- COR107 m 2.OO -

--v-- COR106 m

x m

-3 a o

g 1.75

- - D- - COR105 "o

_ .e - COR104 O

Y Y R<

1.50 - -

?

g -

-2 g g 1.25 - -

g W W o 1.00 - + -

o

<2 4

<s

• \

o si _ j u 3 v. O.75 - -

l l i, -

r, o , ,, o z m -' . 2 0.50 -

jp -

h O.25-- . . E --O l

0.00 ' '

':: 1 - fC i0t  : 'c =' O d : 6=

0 5 10 15 20 25 30 TIME (103 s)

Figure 5.4.33 Core Ring I (node 104-109) Clad Teniperature Predicted by MELCOR for the 2-tubes SGTR (case 2) Base Case Sequence

.I

2.50-SYSTEM 80+ :2- SGTR, (LIMESTONE-WET-SPRAY)

-4 i COR215 2.25 -

....+- COR214 us- COR213 2.00 -

--v-- COR212

~

g m

7 _

_3 5

- - D- - COR211 "o 1.75 -

l - -e - COR210 O

w e

k< 1.50 - -

O jL - 2 $

& 1.25 -

k -

!! ri W g 1.00 -

, ))  :

g o ,

I o

- 1 m 0.75 -

1. I -

m 5

e- "

_; 1 h' b O.50 - [3 -

. .k 0.25-- -

-O r'

O.00 '

o 5 10 15 20 25 30 TIME (103 s)

Figure 5.4.34 Core Ring 2 (node 210-215) Clad Teniperatum Predicted by MELCOR for flie 2-tubes SGTR (case 2) Base Case Sequence

.I

SYSTEM 80+ :2- SGTR (LIMESTONE-WET-SPRAY) 2.50- , , , , , . . . . . . - 4 i COR209 2.25 -

. . . . + . . COR208 un- COR207 g 2.00 -

--v-- COR206 g

_ _3 "

"o - - D- - - COR205 O

O C 1.75 -

- -e - COR204 W W

?

1.50 -

?

. - 2 $

& 1.25 - dl, y -

_ W W

% Q 1.00 -

$'l -

g d . - 1 d I m m 0.75 - -

5 6 g e _ _ -; _

g

'I m O.50 - -

id!

O.25- -

--0

' ' - ' - ' ~ '- '- " " '- -

0.00 '

0 5 10 15 20 25 30 TIME (103 s)

Figure 5.4.35 Core Ring 2 (node 204-209) Clad Teinperature Predicted by MELCOR for the 2-tubes SGTR (case 2) Base Case Sequence

,t

2.50- SYSTEM 80+ .:2- SGTR .

(LIMESTONE-WET-SPRAY)

. . . . . . . -4 t COR315 2.25 -

.....e... COR314

- us - COR313 2.OO -

--,-- COR312 m

_3 g l

a C 1.75 -

- - D- - COR311 "o

-e- COR310 w I w 1.50 - -

l g -

1 6

-2 $

l g

w 1.25 - i j, -

W l l w

[

' W o 1.00 - 'N - o

__J 4 r <

~ -J u o . . u 0 _ j m 0.75 -

m 5 . en 5

z e- ~~;

m _ J a; 52 0.50 -

53 - "

r O.25-- d --O is

" ' - ^ ^ "- ^^ -' ~ ' -

O.00 ' ' '

0 5 10 15 20 25 30 TIME (103 s)

Figure 5.4.36 Core Ring 3 (node 310-315) Clad Teniperature Predicted by MELCOR for the 2-tubes SGTR (case 2) Base Case Sequence 1

2.50- SYSTEM , 80+ ,:2- SGTR (LIMESTONE-WET-SPRAY)

, . . . , . . . . -4 O COR309 2.25 -

. . . . + - COR308 -

as - COR307 g 2.OO -

__ ,-- COR306

~

_3 g "a

C

- - D- - COR305 "

O 1.75 -

< > -*- COR304 O

N N

?

1.50 -

R

-2 $

% 1.25 -

<I 'r -

g W j ',' W o 1.00 - ' -

o 4 .I I a i s o -_s p _ j u t;; m 0.75 _ -

m 6

a a: 0.50

%:n=_< (,

t -

5 a

m O.25-- 'P

+r

--O 4>

' ' '- '^

0.00 ' - " ^ * ' '--

0 5 10 15 20 25 30 TIME (103 s)

Figure 5.4.37 Core Ring 3 (node 304-309) Clad Tennpemture Predicted by MELCOR for the 2-tubes SGTR kase 2) Base Case Sequence

.I

4 SYSTEM 80+ :2- SGTR, (LIMESTONE-WET-SPRAY) 2.50- , , , , , . . . , ,

-4 t COR415 2.25 -

....+.. COR414 IB - COR413 g 2.OO -

--v-- COR412

~

g

_3 "

"o - - D- - - COR411 O

O C 1.75 -

_ _e - COR410 w w m m R

1.50 - -

?

- 2 $

w 1.25 - -

ams w g w

o  ! o t

m < 1.00 - -

tJ _.J _J o _ .d > _ j o y 0.75 -

, f[ -

3 o e z e- m_- -

[] z

! s2 0.50 -

l l _ s2 I

l 4>

l 0.25- -

<r --O t3

' ^ " - ' - ' ' - ' - '-

0.00 ' ' ' '

O 5 10 15 20 25 30 TIME (103 s)

Figure 5.4.38 Core Ring 4 (node 410-415) Clad Temperature Predicted by MELCOR for the 2-tubes SGTR (case 2) Base Case Sequence l

- - _ _ - _ _ . - - _ _ - _ _ _ - . _ _ _ _ .1

2.50_ SYSTEM'80+ :2- SGTR (LIMESTONE-WET-SPR A Y)

. . . . . . . . . . . -4 0 COR409 2.25 -

. . . . + . . COR408 su COR407 g 2.00 -

--v-- COR406 g

_3 "a

C

- - D- - COR405 "

O 1.75 -

_ _e - COR404 O

d "

W R

1.50 -

.R

$ - 1

-2 $

@ 1.25 -

'4 -

W &] W G

w o 1.00 -

'l i!P - o ii <

"I C$

g O.75

- .; ?' elt!*lf I g

_ j d w

h r -

_, - '2 i I h O.50 -

jij ,, 1

fi O.25-- i I -

-O rq' I 0.00 ' ' '

':t' ' '

're W O '

E:2f 0 O 5 10 15 20 25 30 3

TIME (10 s)

Figure 5.439 Core Ring 4 (node 404-409) Clad Temperature Predicted by MELCOR for the 2-tubes SGTR (case 2) Base Case Sequence

SYSTEM 80+ :2- SGTR (LIMESTONE-WET-SPRAY) ' ' '

1.6 . i

,i i ' ' '

s t COR103 w i -

1.5 -

si s ....+.. COR203

1r - - r y '~ 4 .;

, '.t , .g/.- )' m- COR303 -

1.4 -

. . }i ,ai 4 .

--v-- COR403 - 2.O m c m -

1. y- 9

+i :' ,

g 1.3 -

y v v w

f i

w @

m o

1.2 -

il ssv ... N. , ,+ % .. g .,,,, - r 4

Q j __v ' -- 1.5 83 m 1.1-- . ,l a-w -I s ct. w 2 - -

n W 1.O -  :

m w t - Q G

u Q.n O.9 -

d 1 ( _- 1.0 w w 0.8-- I $

O <

t o

0.7 -

lt O.6 -

p V , , . . . . ' i

.5 O.5 50 0 10 20 30 40 3

TIME (10 s)

Figure 5.4.40 Core Support Plate Teniperature Predicted by MELCOR for the 2-tubes SGTR (case 2) Base Case Sequence 4

2.O SYSTEM 80+ :2- SGTR (LIMESTONE-WET-SPRAY)

-3.0

.1 1.8 -

+i -

TEi 2

m 1.6 f, -2.5 C m

v 9 c. :-

w v

9 w I.%.! ' 3 w

$ flN de:

1.4 - [i --2.0 $

< 1: -

t <

$a li 8i

• 1 5 CL 2 1.2 -

p..

,,8;:

2 w a nl w

" ' l  ; "

- 1*5 G

z 9 1.0 -

• l

• l**,' +;  %~ yC-FJm - z 9

u t- ( ,*

r ct:: ai 8 i .. n::

e-- E e .

E *

--+-- RING-1 - 1.O $

W O.8- - <

(s - 4. - RING-2 W.

l 1

Isi- RING-3 0.6 -

_h 1

__y__ gigo_4 -

~ '

O LOW-HEAD O.4 ' ' ' ' ' '

O 10 20 30 40 50 1

TIME (103 s) l l Figure 5.4.41 Lower IIcad funer Surface and Penetration Teinperatures Predicted by MELCOR for the 2-tubes SGTR (case 2) Base Case Sequence

SYSTEM 80+ :2- SGTR (LIMESTONE-WET-SPRAY) . . . . .

600 . . . . .

550--

1. 2 500 -

2

-- 1.O g 6 450- - ,

o 25 -

v z 400 - z o

A .. -

'8 G

8 o

350 -

a a

o E 300 -

e

.6 m -

- m w

C; a

W 4

250 -

. . m to - o m 200 -

.4 w m -

m o - o o 150 -

H2 $_;i$

3 _

100_ -

+-- co -

.2

--m-- co2 50 -

v- cH4 O ='c v' O '= 'T O' '

90 '= '

v c 0 10 20 30 40 50 TIME (103 S)

Figure 5.4.42 In-Vessel Ilydrogen Production Predicted by MELCOR for the 2-tubes SGTR (case 2) Base Case Sequence

i 420 SYSTEM 80+ :2- SGTR (LIMESTONE-WET-SPRAY)

. . . . . . i 410 - -

400 - -

- 14 390 -

g

^ t--

$ 380 - -

m ya 370_ - -

_ y3 [

'1 g 360 - -

B o

a 350 - -

o O 8

o-g 340- - d - -

- 12 2 w -

E y 330 - -

o >

320 - -

0

~ ~

310- -

11 300 -

C/.VITY

~

290 ' ' ' '

O 10 20 30 40 50 TIME (103 S)

Figure 5.4.42 Pool Volume in Cavity Predicted by MELCOR for the 2-tubes SGTR (case 2) Base Case Sequence

SYSTEM 80+ :2- SGTR (LIMESTONE-WET-SPRAY) ,

7o a.00 , , , , , , , , ,

<> C STEAM G 2.75 -

_ . _ ,_ . - O 2

- -e - H2 -

,._ 2.50 -

q>

z --m-- CO2-w -

2

_Z 2.25 -

<> O- CO g 2.00 W _

o ,._ . _ . _ . _ . _ , _ . _ . ,

el 1.75 -

o_ .* , .

z 1.50 -

%,w.-.-.- .a 5 1.25 - 7 _

u , p  !

m o > a g

w 1.00 -

w o'

0.75 .

O.50 -

( //

/

$' F * *' ~ ~ ~ e - ~--- ~

l O.25 -

, / , e-

~~

' - + r d -# -r - ", ~ ~ ,

O.OO C v' = 'c '

='

O 10 20 30 40 50 TIME (103 S)

Figure 5.4A4 Gaseous Mole Fraction Distributed in Upper Compartment of Containment Predicted by MELCOR for the 2-tubes SGTR (case 2) Base Case Sequence

! SYSTEM 80+ :2- SGTR (LIMESTONE-WET-SPRAY)

- 2.75 . . . . . . . . . .

l s

o O STEAM x 2.50 -

--- w - 02 l

' ~ 2.25 -

-9 -

H2 -

Z l w --m-- CO2 2.00 -

o- CO _

1 g ._._._._._ ,._,

z  %.

o 1.75 -

i -

O O 4

z 1.50 -

.s

~

. ,._._ ,_ o -

z 1.25 -

M -

52 <> a l

b 4

1.00 -

i -

v ,

x ..

d" * * " ~ ~ ~ * ' ~ ~ -

u.'

O.75 -

I m / 8

/3 ' ]

':E O.50 f -

/

O.25 -

.- I e i '

O.00 C v '

= 'C '

= "-- ' - * ' - ' * - ' ~ ~ ' '

O 10 20 30 40 50 TIME (103 S)

Figure 5.4.45 Gaseous Mole Fraction Distributed in Annular Compartment of Containment Predicted by MELCOR for the 2-tubes SGTR (case 2) Base Case Sequence

i . o ._

SYSTEM 80+ :2- SGTR (LIMESTONE-WET-SPRAY)

- 2.75 . , , , , , , , , ,

'o

- O STEAM x 2.50 -

-- 02

- + - H2 H 2.25 - _

5 s

---

co2 2 2.OO x o- co _

z  ;

o 1.75 -

a >

u i , . ,._

g g N.'

o 1.50 -

f'. -

a s. , , _ . . . - . .

2 1.25 -

z <>

~ o T' 8 G 1.00 -

i -

< i E O.75 -

/ b'= ' - # " ~ ~ ~ ~ " ~ ~ -

5 1 0.50 0

/,o -v' - -

p IB O.25 -

/ -

__ __ g '

4 /' ="g ' - + " -

47 A ~ P _ '

-v -

O.00 cv '

= 'd ' - '

O 10 20 30 40 50 TIME (103 S)

Figure 5.4.46 Gaseous Mole Fraction Distributed in Lower Compartnient of Containnient Predicted by MELCOR for the 2-tubes SGTR (case 2) Base Case Sequence

i.O SYSTEM 80+ :2- SGTR (LIMESTONE-WET-SPRAY)

^

<> STEAM O.9< > <> . _._ ,m.- 02

- -9 - H2 0.8 -

--m-- co2 o- co n

,. O*7< > -

<> V l<>- ,

< ]

O < '

0.6 -

EE z

9 0.5 - -

G

> 4)

$ 0.4 -

5 $

o 2 0.3 -

> 4 r / I-O.2 r-._._. ._._ ,,

N 9-O.1 '~*'~~'t

• I -

--v / -

0 -l _ , __ _plg,w - /

y ,

O.O c '

= '?#3* '-r'- f ^.^~'----E O 10 20 30 40 50

TIME (103 S)

Figure 5.4.47 Gaseous Mole Fraction Distributed in Cavity Predicted by MELCOR for the 2-tubes SGTR (case 2) Base Case Sequence

4 SYSTEM 80+ :2- SGTR (LIMESTONE-WET-SPRAY)

- 2.75 . . . . . . . . . .

.g

- O STEAM x 2.50 -

--- w - 02

~

-+- H2 2.25 -

--m-- co2 2.00 -

o- co _

w ,

en ~

*-a-y-.-.3.-.-.-y...., <>

7 ,

z_ s '

1.50 - -

a z

o

'v ~._ : i

" i Q 1.25 -

E I w 1.00 - -

o

~ ~. g

~

O.75 -

/ ,

O.50 /

, i >

l -

ll 0.25 -

a l -

/

0.00 = = ' = '=~'-~='~~W - - #^>= = c' o 10 20 30 40 50 TIME (103 S)

Figure 5.4.48 Gaseous Mole Fraction Distributed in IRWST Predicted by MELCOR for the 2. tubes SGTR (case 2) Base Case Sequence

650 SYSTEM 80+ :2- SGTR (LIMESTONE-WET-SPRAY)

UPPER 6OO -

d'

. . . .o . . LOWER 550- - --v-- ANNULAR -- 80 o

^ - - - o- - - CAVITY y 500 -

<> - - + - - IRwsT o

5 450 -

. w w

h 400

~

1 >

60 y w 1- m w w

• i '

8: 350 -

'l >

8:

• - " Z z 300 - _

w 0 y - * - 40 3

_z_ 250 -

_ a W

4 4ly

>- z 5

o 200 -

8 150 - - 0)

T 0  : 7 0 0 : T 0 _ -

20 100  : T 0 0 - _

9 50 ' ' ' ' ' ' ' '

O 10 20 30 40 50 TIME (103 s)

Figure 5.4.49 Containment Pressure Predicted by MELCOR for the 2-tubes SGTR (case 2) Base Case Sequence t

{

SYSTEM 80+ :2- SGTR (LIMESTONE-WET-SPRAY) . .

1.7 . . . . . . . .

2.5

~

_ - - + - - IRWST(atms) ,

--v-- CAVITY (atms) p -

1'5 -

--E-- UPPER (alms)

- ^

[3 g - --e-- ANNULAR (atms) -

2 ~ 0 "'

m tb a o_

--A-- LOWG(atms) -

O w 3.3 _

Ik w w -

g I l1- -

Sh -- 1.5 wM w ct.

o- -

1 1

j a w

w -

H -

g O.9 - 1 5 C

g z - t _- 1.o

^ -

E

< 0.7 Y

5 o _ f> l ('~N

, s - ', ,

o o

0.5 ~ -

? t $ v e' Yp_

il

.5 a i$ I lI

~

M 8 18 -

,9 y Es, F - ,-

g t ~

-=

us+% d L g_" y-O.3 0 10 20 30 40 50 TIME (103 s)

Figure 5.4.50 Containment Atmosphere Temperature Predicted by MELCOR for the 2-tubes SGTR (case 2) Base Case Sequence

4

> m SYSTEM 80+ :2- SGTR (LIMESTONE-WET-SPRAY) 1.O i i . . . . i e i i

~

O.9- - - '

I O.8 - -

-2.5 m 0.7 - -

p E 6

>- O'6- - --2.O >_

W w W w '

s s o 0.5 - -

o 8 -

- 1.5 8 O C O.4 - -

C

< <c O.3- -

-- 1.O o 0.2 - -

i

.5 O.1 - -

O AXIAL PENETRATION O.0 'O ' ' ' ' ' ' '

.O O 10 20 30 40 50 3

TIME (10 S)

Figure 5.4.51 CCI Cavity Maximum Axial Penetration Predicted by MELCOR for the 2-tubes SGTR (case 2) Base Case Sequence

i 3.50 SYSTEM .

80+

2- .

SGTR (LIMESTONE-WET-SPRAY) 3.25 -

0 -

3.00- -

1.O 2.75 -

p2.50_ -

.8 --

2.25 -

6 g 2.00 -

g C

2 1.75

.6 W o o w

m .Is 1.50 -

u -

m >.- >-

t- 1.25- - e--

> -- ,4 >

0 1.00 -

O.75 -

0.50 -

.2 O.25 -

O RADIAL PENETRATION -

0.00 ' ' ' ' ' ' ' ' '

O 10 20 30 40 50 3

TIME (10 S)

Figure 5.4.52 CCI Cavity Maximum Radial Penetration Predicted by MELCOR for the 2-tubes SGTR (case 2) Base Case Sequence

14 ,

SYSTEM 80+

i . :2-SGTR (LIMESTONE-WET-SPRAY)

. i i . ' '

13 - -

- 30 t

12 - s'

,v -

11 - / -

25 n ,- -

o -

x 10 - y n cn n ,- -

s o - m C 9- -

,' o w '

- - 20 O w 8 # w w

w - "

s <

d w m 7- -

l -

d m

, - 15 m

- < 6 -

8

- m o <

S 5 8

o 3

p e -

3

< 4 -

s s

- 10 >e O f -

4 3

I

- O e

8 O H2 -

2- -

v 8

- + - H2O -

5

• --w-- co 1 -

,o o s',,_,_ ,._.- _._v_.- CO2 -

O ' ^ ' ^ ' - " ' " - " " ' ' ~~ ~' '

O O 10 20 30 40 50 3

TIME (10 5) i Ngure 5.4.53 Cavity Gascious production Predicted by MELCOR for the 2-tu

SYSTEM 80+ :2- SGTR (LIMESTONE-WET-SPRAY) 10+ 4  ;

i n

{ t Cl-1(Xe)  ::

,g+3 ,.

-+ - Cl-2(CsOH) (

! -m- Cl-3(Bo) . . 5

--w-- Cl-4(l) 'o:.~ T*7 f"4'*T:7 = N 91O**

x i

- -r- - Cl-5(Te) -

."- 1

. ,s*/ . . -m. i

- -msrr.v.

- - -r -r,-. -. mm

- -o-err v

a -

Cl-6(Ru) #

f -v -

Cl-7(Mo)

- 9+1 g.

,,_,_,_,y_,,_,_,_,_.,_ ,

! - o- Cl-8(Ce) , ,/,..... .......... .. .....  !

'3E  ; - ~ ~

o --A-- Cl-9(La) 8 1/ 4 D m e s.

w 1 O+o r - - o- - Ci-lo(U) pp

~

r Cl-11(Cd) r 2 ]:

" ~

w Q 1O

_i r

Cl-12(Sn)

-8 3 g  ! Cl-13(B) i

" j 2' -2 - - e- - Cl-16(Csi) <

1 m 1O r '

g j l l -

10- f

=

k

~# '

10

^ ^ ^

' ^ ^ ^ ^ ^

1 0+ 3 1 0+ 4 1 0+ 5 NONE TIME (S)

System 80+

BOEJAVNNM 2/27/94 09:09:25 MELCOR Figure 5.4.54 Radionuclides Released from Fuel Predicted by MELCOR for the 2-tubes SGTR (case 2) Base Case Sequence

~

j ,

10 ,

SYSTEM 80+ :2- SGTR (LIMESTONE-WET-SPRAY) t i -

E O Cl-1(Xe) 3

,g+3 ,.

....+- Ci-2(Csos) m m  : - as - Cl-3(Bo) 3 E -

--v-- Cl-4(1) g 1 O+ 2

-[ - -x- . - Cl-5(Te) 1

@ c: Cl-6(Ru) '

I w 1 O+ i F

....p..

Cl-7(Mo) 4

. g...'

z i

- o- Cl-8(Ce) '

4 Cl-9(La) p,', , _

,f m 1O r - - o- - Cl-to(u) _ _ , , , , , . . , , , '~ , ,~ ,

3  : =

~,, ' ,

2 Cl-11(Cd) 1. e - - ' '#&.,. . 'i

-1 -

1O r Cl-12(Sn) .s E  ! -ca Cl-13(B) rqu .

?. s a ........  !

M _,

- - o- - Cl-16(Cst)  :.

E 5 1O F .; .......... -- 1 z

5

~

l' -+--J *h j 1O

_3 N. = I ~

F 7  !

. ,. r ,  :

-s  ;; '

10 . .

1 O*

• 1 O*

• 1 0+

• TIME (S)

Figure 5.4.55 Radionuclides Released to Main Steam Line llouse Predicted by MELCOR for the 2-tubes SGTR (case 2) Base Case Sequence

Table 5.1.1 Summary of MAAP and MELCOR Comparison for the Station Blackout and Sequences (Base Case Calculations)

Major Event MAAP MELCOR Accident intiation 0.0 0.0 Reactor trip 0.0 0.0 Core uncovery 1,92 hr 9,779s (2.72 hr)

Fuel gap release 10,870s (3.02 hr) l Core dry out 11,816s (3.28 hr)

Core support plate failure 3.45 hr 12,630s (3.50 hr)

Reactor vessel failure 3.47 hr 12,656s (3.52 hr)

Commence debris ejection 14,094s (3.92 hr)

Begin concrete attack 14,094s (3.92 hr)

SIT inject 14,501s (4.03 hr)

SIT complete 15,000s (4.16 hr)

Cavity basemat melt-through ~ 8.0d 580,004s (6.71d)

Total H 2in-vessel production 637.0 kg 560.0 kg Total H 2CCI production 1,435 kg CCI radial penetration (24 h) 0.07 m 0.49 m CCI axial penetration (24 h) 0.79 m 1.55 m CCI reached embeded shell 13.89 hr Containment pressure (24 h) 42 psia 44 psia Containment temperature (24 h) 439 K 455 K

• Not reported.

170

Table 5.1.2 MELCOR predicted fractional distribution of . radioactive radionuclides at 14,094 seconds (1,438 seconds after vessel failure) of '

the SBO base case sequence (Dry cavity with Linnestone concrete).

i HELCOR MAAP CLASS NAME CORE CAVITY RCS C0trDOT CONTMN 1 (Ze) Noble Gas 446E+00 .000E+00 .735E-01 .481E+00 .980E+00 2 (Cs) Alkali Metal .457E+00. .000E+00 .383E+00 .160E+00 .127E+00 3 (Ba) Alkaline Earths .907E+00 .000E+00 .634E.01 .296E-01 .710E.02 4 (I) Halogans .100E+01 .000E+00 .162E-06 .123E 05 N/A

. 5 (Te) Chalcogens .922E+00 .000E+00 .528E-01 .248E-01 .114E+00 6 (Ru) Platinoids .996E+00 .000E+00 .258E-02 .120E.02 N/A _

7 (Mo) Early Transition .966E+00 .000E+00 .232E.01 .106E 01 .108E 01 8 (Ce) Tetravaients .100E+01 .000E+00 .490E-04 .224E-04 .110E-02 9 (La) Trivalents .999E+00 .000E+00 .485E.03 .263E.03 .309E-03 10 (U) Uranium .100E+01 .000E+00 .116E-03 .591E-04 N/A 11 (Cd) More volatile .719E+00 .000E+00 .191E+00 .899E-01 .720E.01 12 (Sn) volatile .719E+00 .000E+00 .191E+00 .899E-01 N/A 13 (B) Boron .000E+00 .000E+00 .000E+00 .000E+00 N/A 14 (H2O) Water .000E+00 .000E+00 .000E+00 .000E+00 N/A 15 (Cone) Concrete .000E+00 .000E+00 .000E+00 .000E+00 N/A 16 (CsI) Cs! .600E 07 .000E+00 .708E+00 .292E+00 .960E.01 I

r 171

[

Table 5.1.3 MELCOR predicted - fractional distribution , of radioactive -

radionuclides at 580,000 seconds (6.71 days) during containment melt.

through of the SBO base case sequence (Dry cavity with Lirnestone concrete).

4

............................................................................... q MELCOR MAAP j

..................................... ]

j CLASS NAME CORE CAVITY RCS CONTMN CONTMN I 1 (Ze) Noble Gas .727E 09 .000E+00 . 162E 02 . 990E+00 N/A ,

l I

2 (Cs) Alkali Metal .7505 09 .1173 13 . 3275+00 . 673E+00 N/A 3 (Ba) Alkalino Earths .736E 02 .3085+00 . 802E*01 . 604E+00 N/A 4 (I) Balogens .838E-06 .000E+00 . 439E 03 . 100E+01 N/A 5 (Te) Chalcogens .666E 02 .154E 02 . 305E-01 . 961E+00 N/A 1425 02 N/A 6 (Ru) Platinoida .1085-01 .985E+00 . 3135-02 .

7 (Mo) Early Transition .630E 02 .903E+00 . 340E 01 . 571E 01 N/A -

8 (Ce) Tetravslents .108E 01 .989E+00 . 636E 04 . 460E 04 N/A

.108E 01 .964E+00 520E 03 243E 01 N/A 3 (La) Trivalents . .

10 (U) Uranina .125E 01 .987E+00 . 198E 03 . 147E 03 N/A t

l 11 (Cd) More volatile .443E-02 .622E+00 . 247E+00 . 127E+00 N/A 12 (Sn) volatile .443E 02 458E+00 . 247E+00 . 291E+00 N/A l 13 (B) Boron .000E+00 .000E+00 . 000E+00 . 000E+00 N/A 14 (H2O) Water .000E+00 .000E+00 . 000E+00 . 000E+00 N/A 15 (Cone) Concrete .000E+00 .000E+00 . 000E+00 . 000E+00 N/A 16 (CsI) Cs! .3483 09 .262E 07 . 227E+00 . 773E+00 N/A

\ .....................'..........................................................

1 172

_ ____-_m_m_-._________-_mm_____..--.__m_ _

Table 5.2.1 Summary of MAAP and MELCOR Comparisons for the Small - LOCA Base case MELCOR: Break size = 2.5" diameter at cold leg MAAP: Break size - 2.0" diameter at cold leg, auxiliary feedwater and containment spray available.

Major Event MAAP MELCOR Accident initiation 0.0 0.0 Reactor trip 17.8 sec 0.0 Core uncovery 1.07 hr 412 s (6.87 min)

Fuel gap release -

1980 s (16.33 min)

Core dry out -

3344 s (55.73 min) s Core support plate failure 3.42 hr 3708 s (1.03 hrs)

~

SIT inject 2.0 hr 5294 s (1.47 hrs)

SIT complete 3.45 hr 5424 s (1.51 brs)

Reactor vessel failure 3.44 hr 4733 s (1.31 hrs)

Commence debris ejection -

5250 s (1.46 hrs)

Begin concrete attack -

5250 s (1.46 hrs)

Containment spray 9.96 min no spray Containment failure (p = 155 psia) no 388,000 s (4.49 d)

Total H 2in. vessel production 773 kg 383 kg Total H 2CCI production - 1,166 kg CCI radial penetration (24 h) - 0.49 m CCI axial penetration (24 h) 1.01 m 1.88 m CCI axial penetration at containment failure - 4.53 m l

CCI reached embeded steel containment -

'3,000 s (11.94 hr) structure Containment pressure (24 h) 16 psia 4.04 E5 Pa (59 psia)

Containment temperature (24 h) 120 F 447 K (345 F) 173

i.

Table 5.3.1 Summary of MAAP and MELCOR Comparisons for the MB LOCA Base Case Sequence MELCOR: Break size = 5.0" diameter at cold leg (MB-LOCA)

MAAP: Break size = 9.6" diameter at cold leg (LB-LOCA), auxiliaty feed water available Event Timing MAAP MELCOR Accident initiation 0.0 0.0 Reactor trip 1.1 sec 0.0 Core uncovery 1. initial -

8.23 sec

2. after SIT 1.07 hr 975 s (16.25 min)

Fuel gap release -

138 s (2.30 min)

Core dry out 1. initial -

399 s (6.65 min)

2. after SIT -

3300 s (55.0 min)

Core support plate failure 1.69 hr 5511 s (1.53 hr)

SIT inject 1.1 sec 711 s (11.85 min) _

SIT complete 13.1 min 850 s (14.17 min) ~

Reactor vessel failure 1.71 hr 5169 s (1.44 hr)

Commence debris ejection -

$169s (1.44 hr)

Begin concrete attack -

5169 s (1.44 hr) l Containment spray no no l Containment failure 8.3 d (melt through)" 4.48 d (p = 155 psia)* ___

Total l'I 2in vessel production 381.0 kg 442 @ 24 hr Total 112 CCI production -

871 @ 24 hr CCI radial penetration (24 h) -

.72 m CCI axial penetration (24 h) 1.22 m 1.75 m l

CCI axial penetration at containment failure -

2.75 m' 1

CCI reached embeded steel containment structure - 10.00 br l

Containment pressure (24 h) 48 psia 57.72 psia I 330*F 309'F Containment temperature (24 h)

Extrapolated value. Calculation ended at 230,000 s (2.66 d)

Melt-through does not refer to containment failure i

l 174 l

l

l Table 5.4.1 Summary of MELCOR Predicted Major Events for the SGTR (2 tubes) Base Case MELCOR: MSSV functional, no containment spray, dry-cavity and Limestone concrete.

Event Timing MAAP MELCOR Accident initiation 0.0 Reactor trip 0.0 Core uncovery 5930 s (1.65 hr)

Fuel gap release 7868 s (2.19 hr)

Fuel start to melt ' 8142 s (2.26 hr) i Core dry out 10,899 s (3.03 hr)

Core support plate failure 11,651 s (3.24 hr)

SIT inject 12,173 s (3.38 hr)

SIT complete 12,649 s (3.51 hr)

Reactor vessel failure 11,674 s (3.24 hr)

Commence debris ejection 11,791 s (3.28 hr)

Begin concrete attack 11,791 s (3.28 hr)

Steam generator dryout A 54,000 s (15.00 hr)

Steam generator dryout B 7,500 s (2.08 hr)

Containment failure (155 psi) 678,000 s (7.85 d)*

Total H 2in-vessel production 720 kg*

Total H2CCI production 1,400 kg*

CCI radial penetration (24 h) 0.34 m CCI axial penetration (24 h) 1.38 m CCI axial penetration at containment failure 4.0 m

• CCI reached embeded containment steet structure 57,000 s (15.83 hr)

Containment pressure (24 h) 47.86 psia Containment temperature (24 h) 354.0 F*

• Extrapolated value, calculation ended @ 350,000 seconds l

l l

1 175 l l

l

..l.

Table 5.4.2 MELCOR predicted fractional distribution . of radioactive radionuclides at 11,791 seconds (117 seconds after vessel failure) of -

the 2. tubes SGTR, dry cavity and Liinestone concrete sequence.

CLASS NAME CORE CAVITY RCS CONTMN. . MST.H 1 (Ee) Noble Gas .101E+00 .000E+00 .235E+00 .285E 01 .635E+00 2 (Cs) Alkali Metal .107E+00 .000E+00 .825E+00 .681E .968E 04 3 (Ba) Alkaline Earths .614E+00 .000E+00 .363E+00. .2243-01 .109E 05 4 (I) Halogens .100E+01 .000E+00 .870E 10 .994E-11 .319E 09 s 5 (Te) Chalcogens .667E+00- .000E+00 .313E+00 .2025 01 .473E-04 6 (Ru). Platinoids .979E+00 .000E+00 .199E 01. .117E 02 .587E 07 7 (Mo) Early Transition .850E+00 .000E+00 .142E+00 .858E-02 .419E 06 8 (Ce) Tetravalents .100E+01 .000E+00 .3365 03 .203E 04 .100E 08 9 (La) Trivalents .981E+00 .000E+00 .183E 01 .714E-03 .327E 07

• 10 (U) Uranium .995E+00 .000E+00 .439E-02 .185E-03 .909E 08 6 11 (Cd) More volatile .284E+00 .000E+00 .670E+00 .462E-01 .186E 05 i

12 (Sn) Volatile .284E+00 .000E+00 .670E+00 .4625 01 .186E 05 13 (B) Boron .000E+00 .000E+00 .000E+00 .000E+00 .000E+0e 14 (H2O) Water .000E+00 .000E+00 .000E+00 .000E+00 .000E+00 (

15 (Cone) Concrete .000E+00 .000E+00 .000E+00 .000E+00 .000E+00 16 (CsI) CsI .366E 07 .000E+00 .923E+00 .765E 01 .125E-03

(

l l

i l

l i

l 176

-_ + _ . - __ _~, - . _ _ _ _ _ _ _ _ _ _ _ _ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . _ - _ _ - _ _ - . - . -

l Table 5.4.3 Summary of MAAP and MELCOR Comparisons for the SGTR (2 tubes) Sequence with MSSVs Struck Open, and Containment Spray Available Major Events MAAP MELCOR Accident initiation 0.0 0.0 Reactor trip 18.4 sec 0.0 Core uncovery 1.09 hr 4,881 s (1.36 hr)

Fuel gap release -

7,348 s (2.04 hr)

Core dry out -

9,896 s (2.75 hr)

Core support plate failure 2.52 10,813 (3.00 hr)

SIT inject -

12,892 s (3.58 hr)

SIT complete 2.56 hr 13,483 s (3.75 hr)

Reactor vessel failure 2.54 hr 11,772 (3.27 hr)

Commence debris ejection 12,817 s (3.56 hr)

Begin concrete attack 12,817 s (3.56 hr)

Containment spray 2.54 hr 24,000s (6.67 hr)

Containment failure no no Total H 2in-vessel production 868 kg 568 kg @ 15 hr Total H 2CCI production -

496 kg @ 15 hr CCI radial penetration -

0.33 m @ 15 hr CCI axial penetration <.03m @ 24 hr .92 @ 15 hr CCI axial penetration at - -

containment failure CCI reached embedded - 15.48*

containment steel structure Containment pressure (24 hr) 15 psia .14 MPa (20.0 psia)

Containment temperature (24 h) 105 F* 340 K (152 F )

• Extrapolated value, calculation is ended at 15 hrs.

177

< ~.

l Table 5.4.4 MELCOR Predicted Fractional Distribution of Radionuclides at 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br />, after Vessel Failure of the 2-tubes SGTR Sequence (case 2), MSSVs Stuck Open, and Containment Spray Available HELCOR MAAP

....................................... ........ To CLASS NAME

......................................................CS CORE CAVITY R COtmel MSU{ (ENVIRON) 1 (Xe) Noble Gas .584E-04 .000E+00 .166E.04 .196E+00 804E+00 .938E+00 2 (Cs) Alkali Metal .620E.04 .167E-15 .406E+00 .497E+00 .977E-01 .438E+00 3 (Ba) Alkaline Earths .114E-02 .301E+00 .322E+00 .373E+00 .303E-02 .222E+00 4 (1) Halogens .180E-01 .0005+00 .585E-07 .982E+00 .222E-03 N/A 5 (Te) Chalcogens .1278-02 .165E+00 .195E+00 .621E+00 .174E-01 .540E-02 6 (Ru) Platinoids .196E-02 .982E+00 .157E-01 .389E-03 .137E-03 N/A 7 (Mo) Early Transition .169E-02 .832E+00 .130E+00 .342E-01 .114E-02 .640E-01 8 (Ce) Tetravalents .200E-02 .998E+00 .287E 03 .230E.04 .248E-05 .790E-03 9 (La) Trivalents .198E-02 .968E+00 .764E-02 .220E-01 .477E.04 .600E-03 10 (U) Uranium .399E-03 .997E+00 .199E-02 .141E.03 .128E.04 N/A 11 (Cd) More Volatile .171E.03 .304E+00 .655E+00 .340E.01 .719E 02 .180E+00 12 (Sn) Volatile .171E 03 .283E+00 .655E+00 .347E-01 .719E-02 N/A 13 (B) Borcn .000E+00 .000E+00 .000E+00 .000E+00 .000E+00 N/A 14 (H2O) Water .000E+00 .000E+00 .000E+00 .000E600 .000E+00 N/A 15 (Cone) Concrete .000E+00 .000E+00 .000E+00 .000E+00 .000E+00 N/A 16 (CsI) CsI .637E-10 .1468-11 .357E+00 .534E+00 .109E+00 .453E+00 9

178

I

6. SENSITIVITY STUDY 6.1 Flooding of the Reactor Cavity I

The accident sequences discussed in Section 5 assumed that the cavity flooding system is not I activated during the transient. In this section, we discuss the effect of a flooded cavity before the vessel fails. The accident scenarios considered are the station blackout and 4 small-break LOCA sequences with limestone concrete for the cavity basemat, and the  !

medium-break LOCA sequence with basaltic concrete for the cavity basemat. The use of different types of concrete allows us to investigate the impact of different types of concrete l on CCI. It is assumed that a flow path is connected between the IRWST and the reactor cavity that is open at the initiation of the accident and remains open throughout the entire transient. The water level in the cavity is the same as that in the IRWST.

Station Blackout (SBO) Sequence Although the cavity-flooding system is not actuated for the base case discussed in Section 5, there are about 225 cubic meters of water in the reactor cavity immediately after the vessel's failure. The residual water (about 1.8 cubic meters) in the reactor vessel's lower plenum before failure and the water injected from the SIT are all discharged into the reactor cavity immediately after the vessel fails, as shown in Figure 6.1.1. This amount of water is boiled off at about 47,000 seconds, which is about 9.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> after water is added into the cavity after the vessel fails. Thus, even in the case of a " dry-cavity", the cavity is flooded for a period of 9.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />.

3 For the wet-cavity case, initially there is about 300 m of water in the reactor's cavity, and the water increases to about 340 m3 after the vessel's failure when the SIT water is added to the cavity. Since a flow path is connected to the IRWST, the cavity remains flooded during the entire transient (Figure 6.1.2).

In the CORCON model used in the MELCOR code, the overlying water pool cools the upper crust of the molten core-debris. This cooling indirectly affects the heat transfer at the lower interface between the molten debris and the concrete floor. Thus, the presence of a water pool slows down the erosion rate of the concrete. The axial and radial rates of erosion predicted for this case (Figures 6.1.3 and 6.1.4), are slightly lower than that for the dry-cavity case early during the transient, but are much lower later during the transient. For example, at the end of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, the axial erosion is 1.35 meters for this case, and 1.55 meters for the dry-cavity case. At the time of containment failure, the axial erosion is 2.45 meters for the wet-cavity case and 4.60 meters for the dry-cavity case. Consequently, the hydrogen and carbon monoxide generated during CCI are lower than that in the dry-cavity case, as shown in Figure 6.1.5.

However the additional production of steam from the coriumAvater interaction in the wet-cavity case pressurizes the containment faster than in the dry cavity case (Ref. to Figure 6.1.6). The containment pressure reaches 155 psia (the assumed failure pressure in CESSAR) at about 5.23 days for the wet cavity case and the containment fails from over-pressurization. In the dry-cavity case, melt-through of the concrete basemat occurs at 6.71 179

El days, prior to reaching the containment failure pressure. Containment temperatures are shown in Figure 6.1.7. Except for a few temperature spikes due to hydrogen burns, the temperatures are generally lower than those of the dry-cavity case because of the presence i of a water pool above the molten debris. However, the containment's temperatures still i remain above the design temperature (290 F or 417 K) for a long time.

The gas molar fractions in various containment compartments are given in Figures 6.1.8 to 6.1.12. During the early stages of the transient, the containment is not steam-inerted and MELCOR-predicted hydrogen burns in the cavity, lower, annular and upper compartments.

After about 75,000 seconds, the steam fractions are above 55% and no burns were predicted. In the IRWST region, the steam fraction remains low until about 250,000 seconds. However, due to its low hydrogen content, only two burns were predicted early during the transient.

The major events in the dry-cavity and wet-cavity cases are compared in Table 6.1.1. The major differences are the time and mode of containment failure. A flooded cavity causes a higher pressurization rate in the containment and relatively slower erosion of the concrete basemat; consequently, there is an early containment failure due to over-pressurization. On the other hand, a dry-cavity results in slower pressurization and hence, melt-through of the cavity floor prior to reaching the containment failure pressure.

Table 6.1.2 compares the MELCOR and MAAP predictions for the SBO sequence with a flooded cavity. Both codes predicted that the containment would fail by over-pressurization.

However, the predicted failure time is 2.63 days by MAAP, and 5.23 days by MELCOR.

The earlier time predicted by MAAP is caused by a higher rate of steam generation than predicted in MELCOR. In MAAP, the core debris is assumed to be cooled by the water, so that more heat goes to boiling water and, hence, faster pressurization.

The fractional distributions of radionuclides shortly after the vessel's breach and the containment's failure are summarized in Tables 6.13 and 6.1.4, respectively. The limited results of MAAP analysis are included in these tables for comparison. We note that the environmental release predicted by MAAP after the containment fails is not given in CESSAR, and, hence, cannot be included in Table 6.1.4. Environmental releases predicted by MELCOR also are illustrated in Figure 6.1.13.

Medium Break LOCA Sequence Basaltic concrete was assumed for the cavity basemat for this sequence. As discussed in Section 5.3, the SIT is actuated before vessel failure and the water is boiled off during the period of core degradation. Thus, for the dry-cavity case, only a small quantity of residual water (about 3.75 cubic meters) is discharged into the cavity when the vessel fails. This i

water is rapidly boiled off and the cavity remains dry during the entire transient (Figure 6.1.14). Under the dry-cavity condition, the erosion of the basaltic basemat increases rapidly as shown in Figures 6.1.15 and 6.1.16. Axial erosion reaches the embedded steel shell  ;

located about 1 meter below the floor about 4.8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> after the initiation of CCI, and is l predicted to reach the thickness of the basemat (i.e. 4.57 meters) at about 3.70 days. The l CCI-produced gases are given in Figure 6.1.17. Large quantities of steam and hydrogen are i 180 ,

I i

I

I-produced from the basaltic concrete. (The characteristics of basaltic concrete will be discussed in Section 6.2.) With the addition of hydrogen into the containment, the MELCOR code predicted burns in the cavity, lower, annular and upper compartments between 35,393 and 35,450 seconds. The burns generated a pressure spike of about 700 Kpa (100 psia) and a temperature spike of about 1250 K (1790*F) in the containment, as shown in Figures 6.1.18 and 6.1.19, respectively. The containment appears unlikely to fail by over-pressurization, as indicated in Figure 6.1.18.

For the wet-cavity case, the cavity is flooded with water for the entire transient (Figure 6.1.20). The rates of axial and radial erosion of the cavity basemat are considerably reduced-by the overlying water pool, as shown in Figures 6.1.21 and 6.1.22, respectively.

Consequently, Figure 6.1.23 shows that gases generated from the CCI also are reduced.

However, continued boiling of water in the cavity causes a faster pressurization in the containment (Figure 6.1.24). The MELCOR calculation shows that the containment's pressure reached 1.068 Mpa (155 psia) at about 6.37 days. Furthermore, there is one burn in the cavity at 5,200 seconds, and multiple burns in the IRWST between 160,000 and 200,000 seconds. These burns have a minor effect on the containment's pressure but cause temperature spikes, as shown in Figure 6.1.25.

Table 6.1.5 compares major events for the dry and wet cases. A flooded cavity reduces the erosion of the concrete basemat but increases the pressurization of the containment. The containment is predicted to fail by over-pressurization late during the transient (6.37 days) if the cavity is flooded. However, if the cavity is dry, the enhanced erosion of the concrete causes a melt-through of the cavity basemat much earlier (3.70 days).

Small Break LOCA Sequence Limestone concrete was assumed for the cavity basemat for this sensitivity study. The dry-cavity case, i.e. the base case, is discussed in Section 5.2. Unlike the MB LOCA sequence, the SIT was initiated after vessel failure for the small-break LOCA scenario. Thus, even if th'e cavity flooder is not activated, the cavity would contain about 233 cubic meters of water immediately after the vessel failed. This water is boiled off within about 7.3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> and, then the cavity remains dry during the transient (Figure 5.2.13).

For the wet-cavity case, the cavity was flooded with water for the entire transient (Figure l 6.1.26). The MELCOR-predicted basemat erosion, CCI gas generation, containment pressures, and temperature are given in Figures 6.1.27 to 6.1.31. Major events for the dry and wet cavity cases for the SB LOCA sequence are summarized in Table 6.1.6. A flooded ,

cavity reduces the rate of erosion of the basemat and of gas generation, and causes failure of the containment by over-pressurization prior to basement penetration. A dry cavity )

enhances concrete erosion but, for this case (i.e. limestone concrete), pressurization also is l quite rapid. Therefore, if the cavity is dry, the containment could fail via over-pressurization at about the same time as basement penetration in about 4-5 days.

MELCOR also predicted multiple burns in the IRWST between 120,000 and 166,000 seconds. During these 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br />,11 burnsin the IRWST generate temperature spikes higher than 1100 K (Figure 6.1.30). These burns in the IRWST have a minor effect on the containment's pressure, as shown in Figure 6.1.31.

181 l l

l 6.2 Basaltic Concrete During a core meltdown accident, the type of concrete used in the reactor cavity can influence the pressurization of the containment and the rate at which the core debris penetrates the concrete floor. Most of the accident sequences discussed in Section 5 assumed that the basemat was made of limestone aggregate concrete. Here, the effects of using a basaltic aggregate concrete for the cavity floor is studied in this section for three sequences: SBO, SB- and MB-LOCA. Table 6.2.1 compares the composition, melting temperature and heat of fusion for the basaltic and limestone aggregate concrete. The basaltic concrete contains much less carbon dioxide but more evaporative water. Since hydrogen is produced primary by a steam / metal reaction, it is expected that the basaltic concrete would generate more hydrogen. On the other hand, the basaltic concrete is expected to generate much less CO, which also is a combustible gas. The basaltic concrete has a slightly lower melting temperature, but higher heat of fusion. These physical properties affect the decomposition of the concrete and the erosion of the floor.

Station Blackout (SBO) Secuence As shown in Figure 6.2.1, a SJO sequence with basaltic concrete and a flooded cavity was assumed. Comparisons should be referred to the sequence described in Section 6.1, in which the limestone concrete was assumed and the cavity also is flooded. -

The predicted axial and radial erosion, and gases generated by CCI for this basaltic concrete are shown in Figures 6.2.2 to 6.2.4, respectively. The corresponding information for basalt concrete is given in Figures 6.1.3 to 6.1.5. Comparison of the two indicates that the basaltic concrete results in faster erosion, more hydrogen production, and considerably less production of CO. For example, at the end of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, the axial erosion is 1.9 meters for the basaltic concrete, and 1.35 meters of the limestone concrete. The total amount of l hydrogen produced at the time the containment fails are about 2492, and 1140 Kg for the

. basaltic and limestone concrete, respectively. The total CO produced by the basaltic l

concrete is about 3,750 Kg, about one tenth of that produced by the limestone concrete.

The difference in hydrogen /CO production generates a different combustion behavior I

predicted by the MELCOR code. A brief comparison is given below:

Limestone Concrete Basaltic Concrete Compartment Time,s Time,s l IRWST 1 burn,11,711-11,721 2 burns,11,557-11,801 1 burn,71,196-71,200 Cavity 1 burn,14,301-14,307 12 burns,84,585-157,620 Lower 1 burn,71,196-71,200 none Annular 1 bum,71,196 71,234 rone Upper 1 burn,71,196-71,225 none 182

1 i

l l

The 14 burns in the IRWST and cavity yield high temperature spikes in the IRWST (Figure 6.2.5). However, the temperature spikes are not propagated to the containment.  :

Combustion has minimal effect on the containment's pressure (Figure 6.2.6). l Comparisons of performance of the containment for the basaltic and limestone concretes are summarized in Table 6.2.2. The major differences are the concrete erosion, generation l of gases from CCI, and combustion behavior. Both cases predict that the containment will .

fail by over pressurization at about the same time.

The MELCOR-predicted fractional-distributions of radionuclides after the containment's failure are summarized in Table 6.2.3. A comparison with Table 5.1.3 for limestone concrete reveals that basaltic concrete releases less of all classes of radionuclides to the environment.

Medium Break LOCA Sequence A dry-cavity was assumed for the MB-LOCA sensitivity study. The studies involving limestone and basaltic concrete were discussed in Sections 5.3 and 6.1, respectively. Similar to the SBO sequence, the basaltic case results in faster concrete erosion, higher hydrogen production, and considerably less production of carbon monoxide.

These two cases are compared in Table 6.2.4. The major differences are the time and mode of containment failure. For this dry-cavity scenario, MELCOR predicted that melt-through of the cavity basemat would occur at 3.70 days if the basaltic concrete is used. On the other hand, MELCOR predicted failure of the containment by over-pressurization due to non-condensible gases at about 4.48 days if the basemat is made of limestone concrete.

Small Break LOCA Sequence A dry-cavity also was assumed for the SB-LOCA sensitivity study. The base case with a limestone concrete basement was discussed in Section 5.2.

The predicted extent of erosion of the concrete, the amount of gases generated due to erosion, the containment's pressure and temperature assuming a basaltic cavity are shown in Figures 6.2.7 to 6.2.11. Basaltic concrete again results in faster erosion, higher hydrogen production, and considerably less production of carbon monoxide than the limestone case.

Again, MELCOR predicted that melt-through of the cavity basemat will occur prior to overpressure failure if the basaltic concrete is used. Over-pressurization failure of containment due to non-condensible gases occurs prior to basemat melt-through iflimestone concrete is used. The containment is predicted to fail at 2.75 days for the basaltic case, and later, at 4.49 days for the limestone case. The two cases are compared in Table 6.2.5.

6.3 Steam Generator Tube Rupture Size The rupture of two steam generator tubes was assumed in the SGTR base case described in Section 5.4. The effects of rupture size, i.e. number of tubes ruptured, are considered in the sensitivity study. The study involved two cases, namely, the rupture of 4 and 25 tubes.

183

I The rupture of 2 or 4 tubes is similar to a SB LOCA, while the 25 tube case is similar to a MB-LOCA. The failure of feed water, active safety injection, containment sprays and the cavity flooding systems also were assumed.

As expected, the increased break size results in a faster uncovery, and dry out of the core, and failure of the vessel as summarized in Table 6.3.1, which includes comparisons with the base case (i.e. 2-tube case). The MELCOR predicted reactor-vessel pressure, core water level, core support-plate temperature, lower-head penetration temperature, and the in-vessel hydrogen generation are shown in Figures 6.3.1 to 6.3.10, respectively, for the 4-tube and 25-tube cases.

We note that, for the 25-tube case, the failure of penetration tubes occurs before failure of core-support plate (Table 6.3.D). The situation is similar to the MB LOCA base case discussed in Section 5.3. For all the three cases, hydrogen and steam are discharged through the ruptured tubes into the main steam line house, but the gases do not contribute to the heating and pressurization in the containment before the vessel fails.

Similar to the base case, a dry-cavity and limestone concrete were assumed for the sensitivity study. Although the cavity flooder was not actuated by the operators, the SIT water was discharged into the cavity for all the three cases due to the late initiation of the SITS after failure of the vessel. The reactor cavity was flooded by the SIT water and other residual water from the reactor vessel for about 14 hours1.62037e-4 days <br />0.00389 hours <br />2.314815e-5 weeks <br />5.327e-6 months <br /> for the 2-tube case, and more than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> for the 4-tube and 25 tube cases (Figures 6.3.11 to 6.3.13).

The MELCOR-predicted erosion of the cavity basemat, CCI generated gases, containment pressures and temperatures are shown in Figures 6.3.14 to 6.3.23 for the 4-tube and 25-tube cases, respectively. With 25 ruptured tubes, MELCOR predicted melt-through of the cavity basemat at a relatively early time (4.92 days). This mode differs from the cases involving a few ruptured tubes in which the containment is predicted to fail by over-pressurization later (6.31 days for the 4-tube case, and 7.85 days for the 2 tube case).

The axial erosion when the containment fails is 4.54 m, i.e.,99% of the total thickness of the cavity basemat (4.57 m). This indicates that the containment could fail by over-pressurization at about the same time as melt-through of the cavity basemat (Table 6.3.D).

184

t SYSTEM 80+ SBO (LIMESTONE-DRY .

CAVITY) '

350 _

i i i i

- 12

CAVITY _

325 -

300 -

- 1O l 275 ~ - m en 2

C 250 -

"o E g

--8 c w 225- -

w

E \

3 200 -

3

-s o

175 - --6 O l [m ]

o a

o o

o-150 -

o

> 125 -

-4 >

[-

< 1OO o . .

75 -

- -2 50 - -

25 -

' ' ' ' : O O

O SO 100 150 200 TIME (103 S) 1

! Figure 6.1.1 Water Voluine in Cavity Predicted by MELCOR for SBO Dry Cavity, Liinestone Concirte Sequence

i C kE wEd> dg g>d e

c 2 1 O n 6 5 e 1 1 1 9 8 u q

~ - - e

- - , S

- ~ _ _ _- ~ _ - -

t e

r 0 e r

Y e i 0 c n

T I 6 o V C A i e

' C n

) o 0 t s

Y e T .

0 I ' m V - - 5 i L

A . y C ' i t

v 0 a T C E '

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1 B

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S '

3 M f E I R

M T I

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e e

+ 0 t

c 0 i d

8 ,

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i t

T i v S a Y - -

C S - ' A - - -

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~ - -

0 0 e 0 0 0 0 0 0 0 m 0 0 0 6 4 u 0 8 6 4 2 0 8 6 4 2 1 l

o 3 3 2 2 2 2 2 1 1 V

3 3 r

e t

a m$ w3d> d2 > >6 W 2

1 6

e r

u g

i F

o

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k SYSTEM 80+ SBO -(LIMESTONE-WET CAVITY) i i i i 6.0 i . . i i i i 5.5 -

i 5.0 -

i.

2

_ - 15 4.5- - i m

$ 4.O -

{

x m 3.5 -

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- t-4 .i

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- 1.5- - i 1.0 -

j AXIAL PENETRATION i

O.5 -' --- 24 HOURS 3

O J ' ' ' ' '

0.0 500 600 0 100 200 ,

300 400-i-

TIME (103 S)

Figure 6.1.3 CCI Cavity Maximum Axial Penetration Predicted by MELCOR for SBO Wet Cavity, Limestone Concrete Sequence

.~- ,-a _ _ _ _ _ - _ _ _ _ _ _ _ _ . _ _ . _ _ _ _ _ . _ _ _ _ _ _ _ _ _ . . _ _ - _ _ = = _

i SYSTEM 80+ SBO (LIMESTONE-WET CAVITY) .

1.O . .. . . . . . . g

- -3.O O.9- -

0.8 -

i -

-  : - 2.5 g O.7 -

p

• : 6

--2.O g

0.6- -

i 3

- n:

$O O.5 -

'E O-LM o -

- 1.5 W

,_ O.4 --  ! - >-

: = = = b 5 >

- < E  :

1.0 0

$ 0.3- - o i -

0.2- -

i -

3

.- 5 O RADIAL PENETRATION 0.1 -

[ _

d b  : ........

24 HOURS

,o 0.0 0 100 200 300 400 500 TIME (103 S)

Figure 6.1.4 CCI Cavity Maximum Radial Penetration Predicted by MELCOR for SBO Wet Cavity, Limestone Concrete Sequence

= , - . . - .

t  ;

1 SYSTEM 80+ 580 (LIMESTONE-WET CAVITY) 32.5_ , , , , , , , , , , ,

,,2 - 70 y-30.O -

s____- -

/

27.5-- -

- 60 m 25.O -

e

, m cn o a M '

/ -- 50 m

- 22.5- -

SE?

v 52 / v 20.O -

w w w w -

40 <

< - e - w w 17.5 - i d

d

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15.O - w -

N -

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-- 2 0 O$

8 0

^ -

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' -+- H2O 5.O- _- 10 s

--w-- co 2'5 ' *

- - - -v-*-'-'-~-'- **-'- ---v- - co2

} .m- n

~

O.O '# _" ' "' ' ' ' ' ' ' ' ~ ' '

O O 100 200 300 400 500 600 TIME (103 S)

Figure 6.1.5 Cavity Gases Production Predicted by MELCOR for Silo Wet Cavity, Limestone Concrete Sequenc

1.3 SYSTEM 80+ SBO (LIMESTONE-WET CAVITY) i i i i i e i e i e i i 1.2 -

l 1.1 - ' -

- d> - 150 7 1.O -

0 -

m

& <> a i

v 52 0.9 -

1p ..

o e >

0.8 -

O [,

5 v' vi ts m

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a o

-- 100 g'a_ v Q-O.6 1P '

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r 5

5 0.5 -

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G $ -

, t UPPER - 50 8 t

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i  : - - o- - CAVITY O.1 d"

- - + - - IRWST 0.0 ' ' ' ' ' ' ' '

O O 100 200 300 400 500 600 3

TIME (10 s)

Figure 6.1.6 Containinent Pressure Predicted by MELCOR for SBO Wet Cavity, Liinestone Concrete Sequence 4

SYSTEM 80+ SBO (LIMESTONE-WET CAVITY) , , ,

4 - - +- - IRWST(atms)

O.95 - 1.2

- j --v-- CAVITY (atms) ,

l -- e-- UPPER (atms) -

g O.85 ,

--e-- ANNULAR (atms) C "o -

--4-- LOWER (atms) 1 . O "g v

v g w

w 0.75 -8 d 5

E i- -

l i

4 7

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5 " - 5 0.65 g sW t 52

.6 U T < >

M O.55 4 G M

w w i 2 h

G CE s

4 ,

~

y 0.45

~ y r 5 j , =.es== =& = *L -

.4 M

o _e-+ @- W - 52_- - o o

,- W-t o _- r f-e

• ~~~~~~

.2 O.35 ~ i h O.25- ' ' ' ' ' ' ' ' ' ' ' -

.O O 100 200 300 400 500 600 TIME (103 S)

Figure 6.1.7 Containinent Atinosphere Temperature Predicted by MELCOR for SBO Wet Cavity, Liinestone Concrete Sequence

SYSTEM 80+ SBO (LIMESTONE-WET CAVITY) ,

1.0 . . . . . . . . . . <.- -

O STEAM O.9<g) ---v- - 02 -

- H2 0.8 -

v

--m-- co2 o- Co D

s; O.7<-><> -

o O.6 - -

25 z

52 O.5 - -

C<

h>

- E O.4 -

)

0 3 ly o 0.3 - -

s 0.2 <

r_

O.1 - -

~ . .

O.0

_ Ik ~C'___'s "~.fi-iE&7--h-TMJBN e i* - ie j 0 100 200 300 400 500 600 TIME (103 S)

Figure 6.1.8 Gaseous Mole Fraction Distributed in Cavity Predicted by MELCOR for SBO Wet Cavity, Limestone Concrete Sequence

)

M 0 O EA 2 0

T 2 2 oo 6 S0H cC o c

c O w+mo

^ 0 t n

- 0 e

i 5 n n

) .

M i t

a nc e Y

T W 0 o n Ce u f

o Seq I

V . 0 A 4 t

n C ) e e

~- S i

n e t

r t

T .

3 r c E 0 a po n

- 1 W - 0

( mC

- oe E . 0 E Cn o -

.Y'- M rt N _ 3 I a se O T l T

_ um ni .

S E

M A

nL nt y

I 0 ii v

L

( .

_D20 d a teC ut O b e B

S . m" i

iO trW s

DB 0

+

" 0 nS o r 8

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- 1 c f a

rR M

. E ,

.DE" '

FO eC

%' ~p

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_ Y 'O - r O MM s

S - - - - - - - ' - t uy ob e

O 0 9 8 7 6 5 4 3 2 1 sd a e

_ t Gc i 1 0 0 O O 0 0 O 0 O O

9. der 1 P 6 _

e 5EjzoVz~< z z9 o<E bos: r u

g i

F _.

-eta flll ll\l,1l\ ll, l j! i ijlI

t SYSTEM 80+ SBO (LIMESTONE-WET CAVITY) .,

1.0 . . . . . i e i i i rv -

^

STEAM O.9 -

- - - v- . - 02

- -9 - H2 w -

z m

o.8 -

--m-- co2

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-o-co

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r z

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55:

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53 E

f O.3 -

b o o.2  :-

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~~~.

0.0 r

- '* "^ = ' O d 0 100 200 300 400 -500 soo TIME (103S)

Figure 6.1.10 Gaseous Mole Fraction Distributed in Lower Conipartinent of Containinent Predicted by MELCOR for SBO Wet Cavity, Liinestone Concrete Sequence

SYSTEM 80+ SBO (LIMESTONE-WET CAVITY) i r.

^

1.0 i . i i i i i i i

^

STEAM

- . - ,- - - 0 2 O.9 -

-+- H2

~

w --m-- CO2 z O.8 -

o~ co 3

~

0.7 -

z o -

O V O.6 -

a -

g 0.5 -

z -

o__ O.4 -

U<

l 0 ,& O.3 -

_i

^

g O.2 -.

O.1 4 ,s -

'A D- --_

O.O [ 'S~ ~'" "a________

'D C -

'# NP" = ' o 400 500 600 O 100 200 300 TIME (103 S)

Figure 6.1.11 Gaseous Mole Fraction Distributed in Upper Coinpartinent of Containinent Predicted by MELCOR for SBO Wet Cavity, Limestone Concrete Sequence t 8

1 SYSTEM 80+.SBO (LIMESTONE-WET' CAVITY) ^

1.O , . . . . . . . .. .. .

^

STEAM  !

O.9-< > _ . _ ,_ . _ 0 2

-9 - H2 O.8 -

--m-- co2

- O - .CO M O.7<g -  ;

Sc 95 z__

O.6 - -

z o

0.5 g

t u O.4 -

e w < >

@ O.3 " > -

< > 1 0

0.2 .

7 - * *1-L-

O.1 -

v ' - .- a - - - ~~s -

a p._

l O.0 ._-

T P h m :%-.-,._._._._h. wb - -

_a__ ._

O 100 200 300 400 500 600 TIME (103S) i I

i l

7 Figure 6.1.12 Gaseous Mole Fraction Distributed in IRSMT l Predicted by MELCOR for SBO Wet Cavity, Limestone Concrete Sequence 2 .-- - , v + . . _ - - - , r m.w , . # -- n 4 s----- ,__ r

l 1O, SYSTEM 80+ SBO (LIMESTONE-WET CAVITY) i e i e i i i i i a i s  !

: i Cl-1(Xe)  :  !

' ~

10+3 r E- -

Cl-2(CsOH) , I.

- as - Cl-3(Ba)

--w--  :

l

^ Cl-4(l) g 1 O+2 w

[

---x--- ci-5(Te) 1

C Cl-6(Ru)

H ............g...............g..

'- (" )

b

1. 1O*' r i

z o

! -O- Cl-8(Ce) f - - - - .v-- - - e ,!

-o i

i O, * . :-

l cr

--A-- Cl-9(La) t '...-7 z

w 1O+0 r: - - - o- . - ci-to(U) :s . 7

s

'J . _ . _ . _ . _ .2 - - - - - - - K- ;

7

}

2 Cl-11(Cd) , ,r,-

~

m 1O

-1 r Cl-12(Sn) r i .F l G y Q  ! Cl-13(B)  !!

i.  !

2  : --O-- Cl-16(csi)  :  :

-2

! 5 10 r: __ _ ,,,,,1 i ...  :

c -

. .e - .

. p-1O r F a.... n

,, - - -v- - y ' , -y.- .s

---

c

'4 # . '

10 j

400 440 480 520 560 600 NONE TIME (103 s) l System ~80+

J2DKEDNNM 10/29/93 10:4 7:10 MELCOR Figure 6.1.13 Radionuclide Enviennmental Releases Predicted by MELCOR for SBO Wet Cavity, Limestone Concrete Sequence

. . - _ _ _ _ _ _ _ . _ . _ _ _ _ _ . - - . _ _ _ _ . _ _ _ . _ . _ _ _ _ . _ ~ _ _ _ _ _ _ _ . _ _ ~ _ - . _ _ _ _ _ . - _ - _ ~ - - . _ . _ _ _ . - - - - - . _ . _ _ - _ _ _ . - - - _ _ . - _ _ . _ _ _ _ _ _ _ . . - . - - - _ _ _ . _ - _ _ _ _ - . _ _ - - _ _ _ . _ _ _ _ - _ _ - - - _ . "

W SYSTEM 80+ M- LOCA (BASALTIC-DRY C AVITY) 4.0- . . . . . . . . . i

- 140

.,.  : CAVITY -

3*5 - -

120

~

3.0

m - . .

- 100 ,m__

E - -

6 w 2.5 -

w s -

s 3

o

-- 80 3 o

' 2.0 . I - # --

o a o - - o n-60 o a.

~ > 1.5 - -

3

& t-s--

- 40 <

1.0 - - O O.5-- -

20 7 1

_. 1 _

f ' ' ' ' '

O.0 ' ' '

t  : O O 20 40 60 80 100 TIME (103 S) 1 r

Figure 6.1.14 - Pool Volume in Cavity Predicted by MELCOR for M-LOCA Sequence with Basaltic Concrete and Dn Cavity t

SYSTEM 80+ M- LOCA (B AS ALTIC-DRY .C AVITY) i e > ',

2.75 . . i i i i i 8

2.50_ -'

2.25 -

2.00 -

C

- ~ -

3 1.75 -

>- 5 =

5 w 1.50 -

w

s 2 S So 1.25_ -

4 o D

C 1.00 G 5 -

o

i. m 4 o -

0.75 -

- 2 0.50 -

~

O.25 -

O AXIAt_ PENETRATION O

O.00 80 100 O 20 40 60 3

TIME (10 S) ,

i Figure 6.1.15 CCI Cavity Maximum Axial Penetration Predicted by MELCOR

' for M-LOCA Sequence with Basaltic Concrete and Dry Cavity i

es

l SYSTEM 80+ M- LOCA (BASALTIC-DRY CAVITY) ,

. . . . 6 8 . . . , ,

- 2.5 l

l 7 -

-- 2.O 6--

S Q ,

k 5

- 1 . 5' g w

y 4 -

0 8o >-

N

- - 1.0 +

w 3- -

8 t-u o -

2 - o

.5 1 1

O RADIAL PENETRATION O i ' ' ' ' ' ' ' '

.O O 20 40 60 80 100 TIME (103 S)

Figure 6.1.16 CCI Cavity Maximum Radial Penetration Predicted by MELCOR for M-LOCA Sequence with Basaltic Concrete and Dry Cavity 2

w%

SYSTEM 80+ M- LOCA .

(BASALTIC-DRY CAVITY)

. i 4.5 . . .

/

4.O -

p' -

/

/ -

- 8

/ n 3.5 -

/

M m 3

3.O -

/

/-

8

- 6 ww

- /

2.5 -

,- d y

/ w,,

/ cu

/ - -

m 2.0 -

/ -v,, - 4 <

u .

S '

/

C 1.5 -

s'y /

~

' 4

' / v

' C H2 - 2 1.0 - f - + - H2O

/+ f *'",,.-

/ / --*-- co -

O.5 -

/

- CO2 u

, ,,.-r. - . '#~ ' ' ' ' ' ' ' '

O 0.O 100 O 20 40 60 80 TIME (103 S)

Figure 6.1.17 Cavity Gases Production Predicted by MELCOR -

for M-LOCA Sequence with Basaltic Concrete and Dry Cavity

-______2_ __-__ ___ -_---__g-

- - ++w4- .- e i

SYSTEM 80+ M- LOCA (BASALTIC-DRY CAVITY) 700_ . . . . . . . . . .

_ 100 8

650 - d> -

4 600 -

4 To_ 550-- -

m f$ om 8 500 -

, I 8

M 3

450 - < >

m m -

$ 3

- 60 en O 400 -

5 5 p

4 > Q 350 - 4 -

e-e- 5 5 300 -

d t

3 -

g - 40 a

'" W 250 - -

M

$ 0 UPPER 8 8 2OO <

. . . .o . . LOWER

--w-- ANNULAR 150_ r 20

_.g______ - - - o- - - CAVITY 1OO C_____ -

- - + - - IRWsT 50 ' ' '

O 20 40 60 80 100 TIME (103 s)

Figure 6.1.18 Containment Pressure Predicted by MELCOR for M-LOCA Sequence with Basaltic Concerte and Dry Cavity

SYSTEM 80+ M- LOCA (BASALTIC-DRY C AVIT Y) 1.3 . . . . .

. - - + - - lRWST(otms) l 1.2 - 0 --v-- CAVITY (atms)

() --El-- UPPER (atms) g 11-- --e-- -- 1.5 e q ANNULAR (otms)

"o --A-- LOWER (otms) "o O 1.O -

l c

- C w w cc x o I

) o

< 0.9 - -

x w h l x w

w O.8- - --1.0 g

( > w H 6--

g M w

O.7 - I

) -

M w

s 5 L 1 z P z a O.6 -

7 i a

N lY t C o

o 0.5 yi , % ~ ~ _' '

.5 8 o

- l4e O.4 e,1$~-

j~ - -o 13 N ::EE.DE=45552215 @ 2EEE 0.3 # - - * - ~'~ ~ ~ '- - * ' ' ~' + . . -+.-- r--

0 20 40 60 80 100 TIME (103 s)

Figure 6.1.19 Containment Atmosphere Temperature Predicte<l by MELCOR for M-LOCA Sequence with Basaltic Concrete and Dry Cavity

.9

SYSTEM 80+ M- LOCA (BASALTIC-WET . .

CAVITY) 350 . , , , , , ,

i

CAVITY 340 j- -- 12.O 330. - -

11.5 m

^ 320

- 0

.k-5a o v -

11.O O w 3104 E 5 3 300

- D o

- 1 0 .' 5 d a -

a g 290 -

- 10.0 0 o-

>- 280 -

to t- t-

? R -

-9.5  %

o 270-- v 260 -

- - 9.0 250 -

' ' ' ' ' ' ' ' ' ' ' ' -8.5 240-0 100 200 300 400 500 600 TIME (iO3S)

Figure 6.1.20 Pool Volume in Cavity Predicted by MELCOR for M-LOCA Sequence with Basaltic Concrete and Flooded Cavity 4 9 4

i f

SYSTEM 80+'M- LOCA (B AS ALTIC-WET C AVIT Y) '

6.0 , .. , , , , , , , , ,

5.5 -

i -

5.0 '

j -

4.5- -

3 -- 15 4  :

m  : m 2

v' 4.O -

t-

v

$ 3.5 -

~s-La .

LAJ y .

o 3.0-- i -

- 10 g i

o  : O x

~

2.5 -

>-  : t-o o 2.0 -  : -

i o

C -

1.5- -

i --5 1.O -

i.

-' i  : AXIAL PENETRATION O*5 i ........ 24 HOURS J ' ' ' ' '

O.O ' ' ' ' ' '

o 0 100 200 300 400 500 600 TIME (103 S)

Figure 6.1.21 CCI Casity Maximum Axial Penetration Predicted by MELCOR for M-LOCA Sequence with Basaltic Concrete and Flooded Cavity i,

I

SYSTEM 80+ M- LOCA (BASALTIC-WET CAVITY) 1O . .. . . , , , , ,

0.9-- 3 -

3.0 0.8 -

i -

i

- 2.5 g 0.7 -

j -

7 i 6 g O.6- -

i -- 2.O >_

C i 5

w 2

o 0.5 -  : - 2 w  : o o -

- 1.5 W 3

g C 0.4 -

i - >-

8 5  ! $

O.3- -+ j  : 0-- 1.O 5 0.2 -

.5 0.1 , , . RADIAL PENETRATION _ _

i - - -

24 HOURS 0.0 ) '

' ' ' ' ' ' ' ,o O SOO 200 300 400 500 TIME (103 S)

Figure 6.1.22 CCI Cavity Maximum Radial Penetration Predicted by MELCOR for M-LOCA Sequence with Basaltic Concrete and Flooded Cavity

4 SYSTEM 80+ M- LOCA (BASALTIC-WET C. AVITY) 3.50 . . . . . . . . . . .

3.25,- -v !

7 3.00 - - -

2.75 -- , .w ' ' -

o - E"

- x 2.50 -

/ -

"a V s' -- 5 o "o

C 2.25- -

o w e' w Q 2.00 -

Q b

w 1.75 4 wU x w "

Q 1.50 -

/ -

Q v o - '

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/

3 w ' .k

> 1*OO ' - >

g <

-f ~* ~~ ,

• -- 2 o 0.75 -l W ,

O H2 -

8

' -+- H2O O.50. \ ,- --,-- co

_ j O.25 -$, e

• -.-v-.- CO2 -

~*-*-T-~~' ~'~I~'~

~

J# ' ' '

O.OO ' '

O O 100 200 300 400 500 600 TIME (103 S)

Figure 6.1.23 Cavity Gases Production Prediction by MELCOR for M-LOCA Sequence with Basaltic Concrete and Flooded Cavity

r i 4 ._-

SYSTEM 80+ M- LOCA (B AS AL TIC-WET C AVITY) 1.3 , , , , , , , , , , , ,

1.2 - o -

1.1 -

-r O

7 1.O'~ - o o

.u- 1 o_ v E

v 52 o9 -

w w -

r- x i x 0.8 - a O M W

^

g O7-- o- -

1OO M a_

o-o

.,- g O.6 - ,

z 5 0.5 -

'r - W b

4> <

E Z '

o- >--

E O,4 - z

>- t UPPER >

- 50 0 Z - U E$ O

= o 03 -

. . . .o . . LOWER

--v-- ANNULAR O.2 4

- - O- - CAVITY O.1 -

- - + - - IRWST O.0 ' ' ' ' '

O O 100 200 300 400 500 600 TIME (103 s) l l

l Figure 6.1.24 Containment Pressure Predicted by MELCOR for M-LOCA Sequence with Basaltic Concrete and Flooded Cavity

)

l

SYSTEM

.80+.,hi- LOCA (BASALTIC-WET C A VIT Y) g . . . . . . . .

O.95 $ '

, $$ - - + - - IRWST(otms) -

1 h"Ip --v-- CAVITY (alms) _

-1.2 Ms I - - El- - UPPER (otms)

O.85 !f ""

g , --e-- ANNULAR (otms)

C

% -3 4 1 --A-- LOWER (otms) - - 1.O "g' C i v y

a O.75

_b

} huen i

-- ,a y

5 g l JNI'4 s y 0.65 r

$b -

E h _f' IO" -

.6 O.55 o

M s

i; o <

ll -

g

• g '" 3

< _G < , E 4 <

y 0.45 -

Ip  %

8 g W

' ,e _ W ,o,,c-ge=-e - e - w w w = M ~=Q- rs

+: 8 0.35 M-

+___

-+'* -

~2 a

0.25- '

.O O 100 200 300 400 500- 600 TIME (103 s)

Figure 6.1.25 Containment Atenosphere Temperature Predicted by MELCOR for M-LOCA Sequence with Basaltic Concrete and Flooded Cavity

SYSTEM 80+ S- LOCA (LIMESTONE-WET CAVITY) 370_ , . . , , . . . . .

- 13 36O sg  : CAVITY _

350 -

340-u l

R i -

-- 12 g 3 330 -

C m

a W 320 3

o

[

2

> 310- -

- - 1I 3 o

i=$ 300 -

o o

w

[

h 290 2

E >

< 280 -

- 10 >-

U .b 270 -

<t o

260 -

250 -

240 ' ' ' ' ' ' ' ' ' '

O .100 200 300 400 500 NONE 3

TIME (10 s) 1 Figure 6.1.26 Pool Volume in Cavity Predicted by MELCOR l'or S-LOCA Sequence with Limestone Concrete and Dry Cavity I

= , .

SYSTEM 80+ S- LOCA (LIMESTONE-WET CAVITY) 4.0 . ., , , , . . . . .

- 12 3.5 -

3.0-- i _- 10

$ 2.5_ -

e_ 6 C

3 m l _8 x l'i s

i W

- w 4 o 2.0 -

s u  :

o O -

- 6 0 t- 15 -

• to <  :- 5

- O . 4

-  : o 1.0 -

i _

~

O*5 - 3 - 2 AXIAL PENETRATION -

. i -

24 HOURS O.O ' ' ' ' ' ' ' ' '

O O 100 200 300 400 500 TIME (103 S)

Figure 6.I.27 CCI Cavity Maximum Axial Penetration Predicted by MELCOR for S.LOCA Sequence with Limestone Concrete and Dry Cavity .

. , _ _ _ _ _ _ _ m _ . _ _ _ _ _ _ _ _ _ _ _ _ _ . _ _ _ _

, ,. . ~

SYSTEM 80+ S- LOCA (LIMESTONE-WET CAVITY) 1.0 . .. . . . . . . . .

O.9--  ! .

3.O O.8 -

i -

i

- 2.5 m 0.7 -

i -

m 1 - W

! i 6 y _

0.6-- i

--2.O 3 a:

's i C g 0.5 -

j -

g o -

- 1.5 M l 3 w C O.4 -

i - >

b M 5 0.3--F  :

0  ; -

1. O ' d -

0.2 -

i l . -

.5 0.1 ,, j = RADIAL - PENETRATION _

i -

24 HOURS O.O ' ' ' ' ' ' ' '

,o 0 100 200 300 400 500 3

TIME (10 S)

Figure 6.I.28 CCI Cavity blaximum Radial Penetration Predicted by htELCOR for S-LOCA Sequence with Limestone Concrete and Dry Cavity.

i l

SYSTEM 80+ S- LOCA (LIMESTONE-WET CAVITY) 50 , , , , , , , , , ,

C H2 45- - .

-- 100

-- + - H2O

--w-- co -

40 -

- - - v- - - co2 'l g - - 80 co

. M 35 -

"o v

52 c w 30 -

- w w w d - - 60 5 d 25 -

_y- -

d a

x -e _ _

w m w

w < *' <

O 20 -

s' o

- - 40 >-

3 /

N 15 -

O ,'+ . <r u 10 --i u .x. - 20 5 - e' '-

__p--+----+- -

Y n' ,

0 'r' _O. . . O . . O '

O.

1 l 0 100 200 300 400 500 TIME (103 5)

Figure 6.1.29 Cavity Gases Production Predicted by MELCOR for S-LOCA Sequence with Liinestone Concate and Dry Cavity _

._.___-__.___x - - .. _ _ . . . . . . -_-_-_:=_____.__.---_--_______--..____-------

~ - .. . _ . - _ _ _ _ _

m SYSTEM 80+ S- LOCA (LIMESTONE-WET . .

CAVITY)

. . - 4 2.50_ . . . . . .

- - +- - IRWST(otms)

--v-- CAVITY (atms) 2.25 -

- - e- - UPPER (atms)

--*-- ANNULAR (atms) _

C 2 2.OO - 3 "g "g -

7

--A-- LOWER (otms) v v

g 1.75 g m B . ,

B g 1.50 g ' ' -2 s T*, - W 1.25 E $  :? hi + $

'r } jji j[

g 4

1.00 -

r i w

n 4 .

- 1 2:

s-jj g

['

8 0.75 p4d>

o '

g

('. M _g_;.c 0.50 :h 4 m j 0 0 0 ~C *%

._ %______- - -. - g 0.25- ' ' ' ' ' ' ' '

-0 0 100 200 300 400 500 3

TIME (10 s)

Figure 6.1.30 Containment Pressure Predicted by MELCOR for S-LOCA Sequence with Limestone Concrete and Dry Cavity

SYSTEM 80+ S- LOCA (LIMESTONE-WET C AVITY) 1.1 i i i i i . . . . .

1.O -

i5 o - 14O' O.9 -

m 2 - .. - 120 m

- O.8 -

s 8 25 o w 0.7-- -

- 100 DM 5

m <> m m 0.6 -

lO m , ,

E - - 80 E O.5 - d, -

g w

W 0.4- -

<> -- 6O E z <

w G R >

g O.3_ 5 t

-O-UPPER LOWER

-4O O t-)

O.2 ll - - *- - ANNULAR

/ -._o..- CAVITY -2O O.1 -

- - + - - IRWST O.0 ' ' ' ' ' '

O O 100 200 300 400 500 TIME (103 s)

Figure 6.1.31 Containment Atmospheric Ternperature Predicted by MELCOR for S.LOCA Sequence with Liinestone Concrete and Dry Cavity

1

. * ~ '

360 SYSTEM . .. 80+ . SBO. (BASALT-WET CAVITY)

CAVITY 340- -

-- 12 m 320 -

)'

- 11 3

m y 300 -

B -

o

• o W

a 280~ -

1O d-to

>_ 260 - d E g_

a_

< -9 3 240 - b o

220 - -g 200 ' ' ' ' ' ' ' ' ' ' '

O 100 200 300 400 500 600 3

TIME (10 S)

Figure 6.2.1 ' Voluine of Water in Cavity Predicted by MELCOR for SBO Wet Cavity, Basakic Concrete Sequence

, .~ ,

4.5 SYSTEM 80+ SBO (BASALT-WET CAVITY)

- 14 4.0 -

3.5 - - 12

$ 3.O-- - - 10 m

g 2.5_ -

8 w

o w 2 o

2.0 -

U C

>- - 6 >-

g g 1.5 -

t-Q G - "

_ 4 1.0 -

O.5 ~ -

o -

- 2 O AXi AL PENETRATION O.O J ' ' ' ' ' ' ' ' ' '

0 o

100 200 300 400 500 600 3

TIME (10 S)

Figure 6.2.2 CCI Cavity Maxiinuin Axial Penetration Predicted by MELCOR for SBO Wet Cavity, Basaltic Concrete Sequence O.

3.25 SYSTEM 80+ SBO (BASALT-WET CAVITY) . .

3.00-- " -

1.O 2.75 - -

2.50_- -

.8 7 2.25 -

b 6 c 2.00 - -

.6 5 5 1.75 -

y W o o

m 1.50 - -

W tJ >-

g >_ 1.25-- -- .4 t-l >- >

i 5

o 1.00 -o -

D 0.75 - -

.2 0.50 - -

O.25 " -

O RADIAL PENETRATION 0.00 ' ' ' ' ' ' ' ' '

O 100 200 300 400 500 600 3

l TIME (10 S)

Figure 6.2.3 CCI Cavity Maximum Radial Penetration Predicted by MELCOR for SBO Wet Cavity, Basaltic Concrete Sequence

i i

4.0 SYSTEM 80+ SBO. (BASALT-WET i i i . . .

CAVITY) i i e i

--8 3.5 -

,s, -

i g 3.o -

/ E m

x -

/

,s -

-6 m' o

w 2.5 -

1. O -

C D - -

/ u 4 -

s D w /

4 d w cr 2.o -

,s' -

U w

w o:

r

, --4 m C <

w 1.5 - '

w -

a m - ,/ >-

e i

6 1.o -

-+ ^

- ~=

0

- ,/ - - -+"~ O H2 - 2 e ,. V H2O o.5 - '

,- __ ,-- CO -

< > + _._v-. -CO2 -

o.o # #- * -'-'~~~ # ~ ~~~~~

o o 100 200 300 400 500 soo 3

TIME (10 S)

Figure 6.2.4 Cavity Gases Production Prediction by MELCOR for SBO Wet Cavity, Basaltic Concrete Sequence

- - ~

_+

.m.___.._ __-_ _.________ _ - _ _ - . - _ - _ _ _ w i

i SYSTEM 80+ ,SBO (BASALT-WET CAVITY) e

. .sv i i e i i i O.95 - ', ll -ll - - +- - IRWST(a tms) -

ll ll ' --v-- - 1.2 yj CAVITY (alms) _

-A> 18 i I --B-- UPPER (atms) 1$ T I -

O.85 lli g:::o C g

-- e-- ANNULAR (otms)

"o -

, j --A-- LOWER (atms) _

1 . O "g w

m 0.75 - I,h '

M!

sie i x

w

? - Ak l " '

.8  ?#

• ljll' lflik,

@ O.65 - -

,,84 s

s a

,l W -

ll.

il '

i. i i

$l

~

.6 W M O.55 13 f j' -

M W - l < lil!' h+lpl i W

w @ -

• q.,is

.4-  %

e 0.45 - 7 l,ilii jl'h=i I, ,- - % 0- -

M g

Es w__

o a o , _ o i> h jo b 5 N ' ' # _ 'S -

.2 O.35 ~ 1a -# -

.O 0.25-O 100 200 300 400 500 600 TIME (103 S)

Figure 6.2.5 Containment Atmosphere Temperature Predicted by MELCOR for SBO Wet Cavity, Basaltic Concrete Sequence m_ _. _ . _ _ _ _ _ _ _ . .

1.3 SYSTEM 80+ SBO (BASALT-WET CAVITY) i i i i i i . . . i i 1.2 -

1.1 -

r -

m 1.O d> - 150 l

.cE 0 -

o=

v 9 <> 8 0.9 -

w w x ,

x, a O.8 -

$ o M E O.7-- <> -- 100 o-H g 0.6 z

[3

~

, r y

z O.5 <> Z o

5 z

h u

O.4 -

O-UPPER LOWER 8

- 5o O.3 -

--*-- ANNULAR -

- - o- - CAVITY O.2 -

a

- - e.- - lRwsT O.1 ' ' ' ' ' ' ' '

• - 0 0 100 200 300 400 500 600 TIME (103 s)

Figure 6.2.6 Containment Pressure Paedicted by MELCOR for SBO Wet Cavity, Basaltic Concrete Sequence j ..

m . .. . . . . ..

SYSTEM 80+ S- LOCA (BASALTIC-DRY CAVITY) 6.0 . . . . . . .

5.5 -

5.0 -

4.5- -

- - 15 n n <

3 4.O -

g E 3.5 -

s t; -

w o

E 3.o- -

--- 10 $U

>- 2.s -

s 5 b

[3 w

g 2.O -

Q o

1.5- -

-- 5 1.O -

O.5 '

O

~

AXIAL PENETRATION O.0 ' ' ' ' ' ' '

O O 100 200 300 400 TIME (103 S)

~

Figure 6.2.7 CCI Cavity Maximinn Axial Penetration Predicted by MELCOR -

for S.LOCA Sequence with Hasanic Concrete and Dry Cavity m_m;.._..... _-

- - - - ' ' ' ' ' ' ' ' ' " ' ~ ' ' ' ~ ' ' ' ' ' ' - ' ' ' ' " '

_ _ l

i SYSTEM 80+ S- LOCA (BASALTIC-DRY CAVITY) 2.0 , , , , , , ,

1.8-- -

6 1.6 -

~

5 m 1.4 -

E m v

• k

>- 1.2- -

? - -4 >-

w "

E 1.O -

C o -

8

,__ O.8 -

3 8

>~

g O.6--

N ti

-2 o O.4 -

I 1 O.2 , , . -

0 RADIAL PENETRATION O.O ' ' ' ' ' ' '

O O 100 200 300 400 TIME (103 S)

Figure 6.2.8 CCI Cavity Maximum Radial Penetration Predicted by MELCOR for S.LOCA Sequence with 11asaltic Concrete and Dry Cavity 8 9 I

e

..__ - , . - ~ , . _ . . . _ - _. _ . _ _ . . _ , . _ _ _ _ _ . ..

SYSTEM 80+ S- LOCA (BASALTIC-DRY CAVITY) 25.0 . . . . . . .

^

H2 22.5 - -

-+- H2O -- 50

- _. w - - CO 20.O -

_._w.- co2 -

o _

as-M 17.5 -

- 40 W

52 v 52 v

w 15.O -

w - w 5 -

'y w

[I! 12.5 -

- 30 0 x + -

III x

w / w w

$ 10.O A,

w >-

- - 20

• ~- 7.5

/ -

< /

O <

'g -'-

C.)

5.0 - -

/ -r

/ - w 10 2.5 - / n . . . - - v _ _ . . -

p . - v ,_._.. .. v. - v -

...-v O.O '"*"'... ~ ' ' ' ' ' '

O O 100 200 300 400 3

TIME (10 S)

Figure 6.2.9 Cavity Gases Production Predicted by MELCOR for S.LOCA Sequence with Basaltic Concrete and Dry Cavity 0 0

_ _ _ _ _ _ __ . - __ - . - . . x_ . _m, _-, ___ .____ ___ _ __ _____________

1.O SYSTEM . 80+. S- LOCA.

(BASALTIC-DRY . . .

CAVITY) .

l r 140 i O.9 -

i m 0.8 -

6 -

- 120

~

E

• m 52 0.7- "

v 9 -

_ 100 v 5 ,

w i w

$m O.6 -

d, -

5 g -

o - 80 en g: 0.5 -

o $

9 8:

$ O.4- -

60 e h b w z

a

_z -

$ O.3 <

u 2

o t UPPER - 40 o O

O.2 i O- LOWER _

b

~ --v-- ANNULAR O.1 *-------+-------+------ - - o- - CAVITY --

2O

- - - IRWST O.0 ' ' ' ' ' ' '

O O 100 200 300 400 3

TIME (10 s)

Figure 6.2.10 Containment Pressure Predicted by MELCOR for S-LOCA Sequence with Basaltic Concrete and Dry Cavity

_ _, _ ________--_w

1 SYSTEM 80+ S- LOCA (BASALTIC-DRY CAVITY) 1.5 . . . . . . .

<7

),4 - - + - - IRWST(otms) _

~

--v-- CAVITY (alms) - 2.O 1.3 -

--e-- UPPER (atms) g 1'2 - f3 --e-- ANNULAR (otms) _ C "g

N --A-- LOWER (otms) "g 1.1 _y () ~

w  :

-- 1.5 w a

e 4

- t) m 10 - _ O O_

,_ e--

4 t <

m a m w

cu 0.9 47 a'

7 -

w a_

1 57 ( ) 2 W O.8-L -- 1.O w

.-. t) .--

z w O7 ' - z w

[j :s t3 :s a ;g; "

• O.6 t c a i

7 < > e-z s-e-------,-------w------- -

.5 z o O.5 7'1 rg -y g.cecrgerec e W e*****g o O

y ' O O.4 d, s ~

O.3 4--*-~~~~--*--~~~~~*-~~--~~*-----

.O O.2 ' ' ' ' ' '

O 100 200 300 '4 0 0 i TIME (103 s)

Figure 6.2.11 Containinent Atniospheric Ternperature Predicted by MELCOR for S-LOCA Sequence with flasaltic Concrete and DryCavity

20 SYSTEM .

80+ .:4- SGTR .

(LIMESTONE-DRY .

CAVITY)

O DOME 18 -

--+-- UPP-PLENUM

- - - us- - CORE

- 2.5' 16 i h -

e. - BYPASS

~

69 --o- LOW-PLENUM g 14- -

v- ANN-PLENUM

- 2.O T

=

o 1 e

PRESSURIZER Po c 12 l 4 -

O E _ t O> 1'5 E R a 10 -

~

Q

. .:- ? <

Q 8 -

1 tJ Eo

- - 1.0 E j

t u 6 -

O o

4 -

.5 2 -

O ' ' ' ' ' # =

.O O 5 10 15 20 NONE TIME (105 s)

System 80+

KRDJBTJNM 11 /18 / 9 3 09:20:16 MELCOR Figure 6.3.1 Priinary System Pressure Predicted by MELCOR for the 4-tubes SGTR Sequence with Limestone Concrete and Dry Cavity

l 16 SYSTEM .

80+ :4- SGTR (LIMESTONE-DRY CAVITY) t DOME l 14 - +- UPP-PLENUM.- _

= CORE

-v- - BYPASS l 7 12 _ , _

x- - - El- - LOW-PLENUM

~

v g 1 - -m - ANN-PLENUM d

> 1o - 1 -e- PRESSURIZER _

w 1

[ 8

......., 0 0 0 0 W ~

'+. . \. -

g a

- l' - n - -

n -a - - -

- + -

.~.~- \

-s l o 6 -

o I tJ IJ W oo cr 1 o a 4 -

s'

-e - - - -

• e-- - , v= f- v= v= y=

2 -

D -

- - - x- - - - _z __ _ _ _ .a

' ' ' -' 4 r - - - ' - - * " c '=

O - - - + -

l O 4 8 12 16 20 l NONE TIME (103 s)

System 80+

KRDJBTJNM 11/ 18 / 9 3 09:20:16 MELCOR Figure 6.3.2 Vessel Collapsed Liquid Level Predicted by MELCOR for the 4-tubes SGTR Sequence with Limestone Concrete and Dry Cavity l

t

h,'

2.D0. SYSTEM 80+ :4- SGTR (LIMESTONE-DRY CAVITY)

- 4 t COR103 2.25 -

- - + - COR203 ul- COR303 g 2.00 -

--v-- COR403 n

, _ 3 g 5 1.75 -

w 4- w cr  :-' cr R

1.50 -

e '

r R

\

!  : gif*., N - 2 'j g 1.25 -

h * .

D.., h -

g w I , w

,. s ,_-

~

y W 1.OO - 1

, p' .,N .,

- w w < s e s . N <

S O.75 ~

's Y?-W *-M ~

l '*-

w -

f -, m a

O

=w a o

O.50 -

0.25-- --o O.00 '

0 ' '

0 *

'e i o

O 10 20 30 40 TIME (103 s)

Figure 6.3.3 Core Support Plate Teniperviire Predicted by MELCOR for the 4-tubes SGTR Sequence with Limestone Concrete and Dry Cavity

2.50- SYSTEM ,

B0+ , :4- SGTR .

(LIMESTONE-DRY CAVITY) .

. -4

....+.. gr <;_1 2.25 -

_ _,. __ p p g _2

- mu - RING-3 g .2.OO , -

"o  : M.

__,__ pino_4 O LOW-HEAD

-_ 3 "g C o 1.75 -

?., i 1. -

C N '8

,.-. N D

1.50 -

.\

u h. C N,s

. 8 D

e-is a_

2 1.25 -

p ,t.-

__ _  %%s s -

- 2 o-2 w .h N% w i

z 9

1,o0 -

, f:

M, 8

8

/+

k s z

l Ut *- 8  % 9 o

&,_. 9.,5 - _

f, f

%... - h-% W am-4 .....- .... 4... ,,, ......+.... 1 6--

, ,s &_

E m

o-

_ _ M I,y (,',

E m

O.50 -

- o-O.25-- -

-0 0.00 ' ' ' ' ' ' '

O 10 20 30 40 TIME (103 s)

Figure 6.3.4 Lower llead Inner Surface and Penetration Tennperatures Predicted by MELCOR for the 4-tubes SGTR Sequence with Limestone Concrete and Dry Cavity e I

l. ._.

t 600 SYSTEM . .

80+ .

4-. SGTR . .

(LIMESTONE-DRY CAVITY) 550.

f 3-'1.2 l 500 _

m ^

Q 450- n __ '1,o y o

C 5

p 400 _

2 o - o a

o 350 _

.8 m o

o .. O E 300 _ @

a:

m -

'6 M M 250 _ m

- w a m w

oc 200 -

, , _ g o -

.4 w o 150 or E; -

o

H2 O' 100-" +- co -

.2

- - m-- co2 50 ~

v- CH4 O i 'T O '= ';g i=. y ;

i i

=i 3 . _

0 150 300 450 600 3

TIME (10 S)

Figure 6.3.5 In-Vessel Ilydrogen Production Predicted by MELCOR for the 4-tubes SGTR Sequence with Liinestone Concrete and Dry Cavity

_ _ _ _ _ . . . _ _ . _ . _ _ _ _ _ _ _ . ________.__m

, s .

20 SYSTEM 80+:25- SGTR (LIMESTONE-DRY CAVITY) i . . . . . . . i

^

DOME l 18 -

! - - +- - UPP-PLENUM

- 2.5

- - an- - CORE 16 ll j -4 - BYPASS

~

, q n i o- LOW-PLENUM l g 14- -

j -v- ANN-PLENUM -- 2.O cx. T t

o_

i = i  : PRESSURIZER m v

9 12 1

. E  : _ 9 VB at 3300 sec v w '> i w m 10 -p

i. _

1.5 g m

m  :. m LAJ W

m -

x l ' 8 - - o-M - -

- 1.0 W d

w 8 6 -

8 4 -  : _

i -

.5 2 -

i -

O - -- - - '~ -

.O O 5 10 15 20 NONE TIME (103 s)

System 80+

KLDOAMHNM 11/12 / 9 3 16:05:34 MELCOR Figure 6.3.6 Primary System Pressure Predicted by MELCOR i for the 25-tubes SGTR Sequence with Limestone Concirte and Dry Cavity.

1 20 SYSTEM 80+:2 5- SGTR (LIMESTONE-DRY CAVITY) i

^

18 DOME i _._,_.- UPP-PLENUM -

16 -

--m-- CORE j

m

-+- BYPASS -

i 5 14 -

i c.

LOW-PLENUM M ANN-PLENUM -

a i W 12 -

i VB of 3300 see w  :- -

J ow 10 - '

m  : -

m , .  :

a 8  %..~ ._.  :

g  : ._._:._._._ -

U w

u \ i

> 6  :

a: s -

3 4 -

3

_e. ___

o 4 m =-ww 2 ~e-,__-

K .__._y.___

i

~1 -

O ' ' ' " " -* * * * + "" -*- + ' ' -

0 2 4 6 NONE 8 10 12 14 3

System 80+ TIME (10 S)

KLDQAMHNM 11/ 12 / 9 3 16:05:34 MELCOR Figure 6.3.7 Vessel Collapsed Liquid Level Predicted by MELCOR for time 25. tubes SGTR Sequence witti Liiiiestoine Concrete and Dry Cavity

_ _ _ _ _ _ _ _ _ . _ _ - - - - - - - - - - - - - - - - - - ^ ^

l l

l l

l l

SYSTEM 80+:25- SGTR (LIMESTONE-DRY CAVITY) , -4 2.50. , ,

t COR103 2.25 - -

t-- COR203 m- COR303

~~

2.OO - --v-- COR403 _3 g g

m

, m o

o -

O O 1.75 -

w w m m

, _ _ , _ _ _ -v------ E 5

1.50 -

~ _- _ _ _

- -m- <

--- " ' O --

- 2 $

.- *+........... +

ig 1.25 -

. O w ', .

t--

w w 1.00 - . is .. ' '_W

'X -

4

>~~'

• p r

N ,6 - I '2-O.75 -

w

$ W m

m o

o -

O

" O.50 -

--0 O.25 --

0.00 40 O 10 20 30 TIME (103 s)

Figure 6.3.8 Core Support Plate Teniperature Predicted by MELCOR for the 25-tubes SGTR Sequence with Liinestone Concrete and Dry Cavity

~ ' '

t 2.50_

SYSTEM 80+:25- SGTR (LIMESTONE-DRY CAVITY)

. . . . . . . - 4

. . . . + . . RING-1 2 25 -

- + - RING-2 us - RING-3 g 2.OO -

--v-- RING-4

~

_ 3 g "o 9 LOW-HEAD "o C

C 1.75 - -

& H W. W

?

1.50 -

n If /.5

.w ' .

R a> f.#/ - 2 5 sW 1.25 -

) is U$

V m if

=

/4'/

l W

z 1.00 - z l-;

9 w s ~pn. w- . s.r . .n

. = .g .

9 w

i - 1 <

W w

O.75 - l W

w 5

m o.50 dl 5

a 0.25-- -- 0 0.00 ' ' ' '

O 10 20 30 40 TIME (103 s)

Figure 6.3.9 Lower llead Inner Surface and Penetration Temperature Predicted by MELCOR for the 25-tubes SGTR Sequence with Limestone Concrete and Dry Cavity

SYSTEM 80+:25- SGTR (LIMESTONE-DRY CAVITY) 800 , , , ,

700 -

1.5 n

2 3 600 -

v o_

v z z o '

o P

O 500 -

A 5 -

- 1.0 8 b 400 [ - Ocr y e.n W m m m e 300 - -

yo w s w

8 - -

'5 8

g 200 -

H2 g

....+.

• Co 1OO - ? --m-- co2

-v- CH4 0 =' T 5 6 9 '= ';c' = '

7 c = ,o 0 100 200 300 400 500 TIME (103 5)

Figure 6.3.10 In-Vessel Ilydrogen Production Predicted by MELCOR for the 25-tubes SGTR Sequence with Limestone Concrete and Dry Cavity

225 SYSTEM 80+ :2- SGTR (LIMESTONE-DRY CAVITY)

CAVITY 200- - -

- 7 175 - - -

- 6 mm 9 . .

y v

150 - -

o w

2

- 5 C 8 125 - -

3

~~ - 4 d.

8 100 - -

_.s

- 3 a8 w

M u

y 75 - -

n

~__

- 2 <o 50 - -

25- - -

1

-r O ' '

f o

O 75 150 225 300 3

TIME (10 S)

Figure 6.3.11 Pool Volume in Cavity Predicted by MELCOR for the 2-tubes SGTR Sequence with Limestone Concrete and Dry Cavity

1 300 SYSTEM 80+ :4- SGTR (LIMESTONE-DRY CAVITY).

CAVITY 10 275 - -

250 - -

225-: . -- 8 W G C d 200 - -

52 w v

$ 175_ - -

6 5 o

1. ~~ 5-150 -

S O a a_ 125 - -

8 ,.

U

• 3

- 4 m  ;

[-

100  ;.,

g

" y 75 - - <

o

- 2 50 - - -

25 -

O ' ' ' '

t O

O 150 300 450 600 TIME (103 5) l Figure 6.3.12 Pool Volume in Cavity Predicted by MELCOR for the 4-tubes SGTR Sequence with Limestone Concrete and Dry Cavity

SYSTEM .

80+:25-SGTR.

(LIMESTONE-DRY CAVITY) 350 -

-- : CAVITY -

- 12 300 -

- 1O E G ~

b E 250 -

."52 w v 2 -

-- 8 w D, s h 200 -

h a >

o -

6 o a o- 150 - o o

D$ >- o-e t- e _

s

- 4 D 100 -

5 c.)

50 ~ <- -

- 2 da O ' '

O O 100 200 300 400 500 3

TIME (10 S)

Hgure 6.3.13 Pool Volume in Cavity Predicted by MELCOR for the 25-tubes SGTR Sequence with Limestone Concette and Dry Cavity

, , . .i SYSTEM 80+ :4- SGTR (LIMESTONE-DRY C AVITY) 5.0 , ., , , , , , , , , , , ,

15 4.5-- i 4.0 -

i m 3.5 -

i E i m t

10 3 M 3.0 -

i n-  :. cc.

i._

w w m  :- :s o

o w

2.5 -

w o o 3

C 2.O i W

o e-5 1.5- -  : --5 0 1.0 -

i _

AXIAL PENETRATION O.5 , .

........ 24 HOURS J ' ' ' '

O.O e e O

' ' ' i i i i O 150 300 450 600 TIME (103 S)

Figure 6.3.14 CCI Cavity Maximum Axial Penetration Predicted by MELCOR for the 4-tubes SGTR Sequence with Limestone Concrete and Dn Cavity l

l

2.75 SYSTEM 80+ :4- SGTR ,(LIMESTONE-DRY CAVITY) 2 o  : _,

2.50 -

i -

. 8 2.25 -

i -

m 2.00 -"  ! -

?52 1.75 -

5 i -

- ' 6 C 6

>- cr g

w 1.50 -

o i - '--

m s

2 O w

8 o

1.25_- i

-_ - 4 a M

>=4

- 1.00 -

< tb o o 0.75 -

i -

! - . 2 o.50 -

0 RADIAL PENETRATION O.25 w>

i - -

24 HOURS 0.00 ' ' ' ' ' '

• i 0 1 .5 0 300 450 600 3

TIME (10 S) i Figure 6.3.15 CCI Cavity Maximum Radial Penetration Predicted by MELCOR for the 4-tubes SGTR Sequence with Limestone Concate and Day Cavity  ;

i

4 -

SYSTEM 80+ :4- SGTR . .

(LIMESTONE-DRY . .

CAVITY) i i i . . i i i

~~

- v-'

.- g- 80 35 -

• y -

,x '

- ,s' '

30 -

/

, , .n -

! n ,' ,/ n O --"

,e .

- 60 I o 25 - ' / - o C ,W .V G l '

w - e . _ w t w ' / w

' 4 4 /

w 20 ' w I -s

,- -/ -

a W -

4 j 40 a w w i

1. 15  ! 4 I

N w l -

O .

y / ./

w >- s e >-

t-- _e /

6--

< 10 -+

t  ; _ - + - - 5 o ,, 4 o

- s , ,. -- 20

/ - O H2 i V

a

- H2O l'

5 *

,1 ,' --w-- CO

~

t

y. 9 9

. . -; / n ,~

- - ~ v- - CO2 -

1. "' ' "' ' Y ' ' '" ' '

O o-O 150 300 450 600 TIME (103 S) t Figure 6.3.16 Cavity Gases Production Predicted by MELCOR for the 4-tubes SGTR Sequence with Limestone Concrete and Dry Cavity .

t

1.3 SYSTEM . .

80+ .:4- SGTR .

(LIMESTONE-DRY CAVITY) 1.2 -

1.1 -

^ '

- 150 cE 1.O -

"o' _E_

C o,9 _

w o: h4 o

5 m

0.8 -

g w w a:

8: O.7- -

-- 100 o-s w

g 0.6 -

y 1 &

E O.5 -

z o O.4 - t UPPER _

8 o O- LOWER

- 50 0.3 -

--w-- ANNULAR -

--E>--- CAVITY O.2 -

- - + - - IRWST O.1 - - * - - * - - * - ~ - - - - ' - - * - - - ~ - - " - - " - -

0 100 200 300 400 500 600 TIME (103 s)

Figure 6.3.17 Containment Pressure Predicted by MELCOR for the 4-tubes SGTR Sequence with Limestone Concrete and Day Cavity

_ _ _ _ _ _ , ._m_. _ _ _ _.__ __ -

4 4 N SYSTEM . .

80t :4-SGTR (LIMESTONE-DRY CAVITY).

O.95 -

--+-- IRWST(atms) -

~

--v-- CAVITY (otms) _

- 1.2

- - e-- UPPER (otms) g O.85 -

--e-- -

ANNULAR (atms) C 9

~

- --A-- LOWER (otms) -

1. O mo

- =

w a:

0.75 - -

w cx 3

-- . 8 3 5c' 0.65 -

- 5

• cn w 2 t-- -

- . 6 d

,, M O.55 2' - t;-

u w s ,, c -i u

a;;

< ~

a ,

,_v--___y_______-v__---

_ _ _ _6 - s es s :"_ ^ _6"_V ,, ,,*O y-

-- )

.4 y

--z z O.45 a 7 8 ir .::__tr _ ._ _ - e z

a $

O.35 ~ ,

__+_____.__,_______+_______+-_____

.2 0.25- ' ' '

.O O 100 200 300 400 500 600 3

TIME (10 s)

Figure 6.3.18 Containment Atmospheric Temperature Predicted by MELCOR for the 4-tubes SGTR Sequence with Limestone Concrete and Day Cavity

)

6.0 SYSTEM 80+:25- SGTR (LIMESTONE-DRY ,

CAVITY) 5.5 -

i.

5.0 -

3 4.5-- 3 -- 15 m  : -

H 3E 4.O -

6 h

y 3.5 -

i M

b o 3.O--  : -- 10 2E i.a  : o to  !

u > 2.5 -

" t-3 D -

g 2.0 -

j Qo 1.5-- -- 5 1.O -

i

[.

O AXIAL PENETRATION O*5 -

g ........

23 HOURS O.O - ' ' ' '

o 0 100 200 300 400 500 3

TIME (10 S)

Figure 6.3.19 CCI Cavity Maximum Axial Penetration Predicted by MELCOR for the 25-tubes SGTR Sequence with Limestone Concrete and Dry Cavity

. _ _ . _ _ _ _ _ _ _ _ . _ _ . _ _ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . _ _ . _ _ _ _ _ _ ____._____.m__.____ .. -

1.O SYSTEM .,80+:25- SGTR (LIMESTONE-DRY CAVITY)

O.9~ -

! --3.O 0.8 -

i -

i -2.5 n 0.7 -

i.

n 2

U i b g 0.6- -

i.

- - 2.O 3 a:

b  : +

o 0.5 -

o -

- 1.5 W ou C- O.4 -

i m >  :

O.3- ,e  :  : e - 1.O o 0.2 -

i

• i -

.5 0.1 j = RADIAL PENETRATION o ,_

24 HOURS 0.0 / ' ' ' ' ' ' ' l

.O O 100 200 300 400 500 TIME (103 S)

Figure 6.3.20 CCI Cavity Maximum Radial Penetration Predicted by MELCOR for the 25-tubes SGTR Sequence with Limestone Concrete and Dry Cavity

__ -_._- _ . _ . _ _ _ _ . _ . _ m _

~

1

.L SYSTEM 80+:25- SGTR (LIMESTONE-DRY CAVITY) .

' 50 . . . . . . . .

-v' - 100 -

45- - ,

40 - ,-

n '

w' n m

o - 80 M 35 W

9 e ,

- ~

- w w 30 -

V m w '

3 -

1. • 1. ,.' - 6O 6 d '

d cr 25 -

e' -

cr ,

s m w m b @ 20 -

, ?' ,

,Y -

-4o

~ .- L_

l 15 _

> 4 <-

l < .,4 0 l o '.-

D ~

H2 e' .-

10__ * -

H20

_ -2O i * <W .-+~ --w-- CO >

5 l C~

_!y

. , ./, . - _._v_.- CO2 .

' ~ ' ' ' ' ' " '

O O '

O 100 200 300 400 500 i

3 TIME (10 5) l Figure 6.3.21 Cavity Gases Production Predicted by MELCOR'  !

for the 25-tubes SGTR Sequence with Limestone Concrete and Dry Cavity

.9

t SYSTEM 80+:25- SGTR (LIMESTONE-DRY CAVITY) 1.3 . . . . . . . . i 1.2 -

1.1 -

150 cE 1.O -

E v E.

C 0,9 _

w m

E B 0.8 -

p to w w m o-E O.7-- -- 100 5-f y

=

~

z O.6 -

Q s

W E O.5 -

< z

$ 0.4 -

t UPPER _ 8 O -

-O- LOWER - 50 0.3 - --w-- ANNULAR -

- - o- - CAVITY

~

l

- - e- - IRWST O.1 ' ' - - - + - - " - * - ~ - - - * - * - -'-----*---'-,-**--

0 100 200 300 400' 500 TIME (103 s)

Figure 6.3.22 Containment Pressure Predicted by MELCOR ,

for 25-tubes SGTR Sequence with Limestone Concrete and Dry Cavity

4 . . .-

SYSTEM .

80+:25-SGTR (LIMESTONE-DRY .

CAVITY)

O.95 - - + - - IRWST(otms) -

-:7 --v-- CAVITY (atms) _

- 1.2

- - e- - UPPER (alms) g O.85 -

--e-- ~

ANNULAR (atms) C "o -@ --A-- LOWER (otms) -

1. O ma C O w

m 0.75 '7 -

w o m

~ o

< -cr -- . 8 ~

m i m u O.65 - - w o- .

o_

1 1 w .

w

~ _

.6 ~

-l { -

~ O 55 M ~

'u" z -

z W If

,, ~______,_______y------+ W

$ 0.45

-. i

_ _ -ge_~~C W- .

4 @

% l l, _ _ ~ _-$~~___ _ -

~,

8 o.3:z=e*3_.

g

-O.35 ~W _

.2

__+_______,_______+_______+-_____-

0.25- ' '

- . O O 100 200 300 400 500 TIME (103 s)

Figure 6.3.23 Containment Atmospheric Temperature Predicted by MELCOR for the 25-tubes SGTR Sequence with Limestone Concrete and Dry Cavity

_j

l Table 6.1.1 Effects of Flooded Cavity for the SBO Sequence Dry Cavity Wet Cavity Cavity Water in cavity before VB 0 299.0 m 3 Water in cavity immediately after VB 225 m 3 340.0 m 3 Water in cavity @ Cont. failure 00 251.0 m 3 CCI .

H2 Production from CCI 1,435 kg 1,140 kg Radial abrasion @ 24 hr 0.49 m 0.36 m Axial abrasion @ 24 hr 1.55 m 1.35 m CCI abrasion @ Cont. failure 4.60 m 2.45 m DT required CCI to reach embedded 9.97 hr 11.23 hr containment steel shell*

Containment Pressure @ 24 hr 3.03x105 Pa (44 psia) 3.85x105 Pa (56 psia) l Temperature @ 24 hr , 455 K 402 K Pressure @ Cont. failure I

6.58x105 Pa (96 psia) 1.07x106 Pa (155 psia) l Temperature @ Cont. failure 532 K 447 K Containment failure melt-through*

• over pressure Time of containment failure 6.71 d 5.23 d Time measured from the initiation of CCI

" Melt-through does not refer to containment failure l

l 250

Table 6.1.2 Comparison of MAAP and MELCOR Predictions for the SBO Sequence with Flooded Cavity Major Event MAAP MELCOR Containment failure p = 155 psia) 2.63 d 5.23 d Total H 2in-vessel production 637 kg 527 kg Total H 2CCI production 1140 kg CCI radial penetration (24 h) 0.07 m .36 m CCI axial penetration (24 h) 0.07 m 1.35 m CCI at containment failure 2.45 m CCI reached embedded steel shell 14.72 hr Containment pressure (24 h) 64.0 psia 55.8 psia Containment temperature (24 h) 414 K 400 K

• Not reported 1

l l

251 l

]-

Table 6.1.3 MELCOR predicted fractional . distribution of. radioactive radionuclides at 12,581 seconds (1,233 seconds after vessel failure) of the SBO wet cavity and Limestone concrete sequence

!ELCOR. M;J@

CLASS NAME

....................................................,.,RCS CORE CAVITY CO!7tMN E!WIRON CCITIMN . >

1 (Xe) Noble Gas .167E-10 .000E+00 .9132 03 .578E-02 .993E+00 .980E+00 2 (Cs) Alkali Metal .972E-11 .178E 13 .151E+00 .748E+00 .101E+00 .440E-02 3 (Ba) Alkaline Earths .136E-01 .394E+00 .891E-01 .-503 E + 0 0 .140E-05 .295E-06

-4 (I) Halogens .453E-06 .000E+00' .566E-04 .547E 02 .994E+00 N/A 5 (Te) Chalcogens .124E-01 .198E+00 .430E-02 772E+00 .138E-01 .230E-04 6 (Ru) Platinoids .215E-01 .974E+00 .334E-02 .998E-03 .152E-06 N/A 7 (Mo) Early Transition .119E-01 .891E+00 .408E-01 .562E-01 .263E-05 .120E-05 8 (Ce)

P Tetravalents .216E-01 .978E+00 .699E 04 .315E 04 .191E-07 .110E 07 9 (La) Trivalents .216E 01 .973E+00 .,600E-03 .519E 02 .890E-08 .850E-08 10 (U) Uraniu:n .459E-01 .954E+00 .'191E-03 *

.776E-04 .152E-07 N/A -

11 (Cd) More Volatile .660E-02 .649E+00 .263E+00 .813E-01 .340E 05 .160]!:+00 12 (Sn) Volatile .660E 02 .605E+00 .263E+00 .125E+00 .123E 04 'N/A 13 (B), Boron .000E+00 .000E+00 .000E+00 .000E+00 .000E+00 N/A 14 (H2O) Water .000E+00 .000E+00 .000E+00 .000E+00 .000E+00 N/A 15 (Conc) Concrete .000E+00 .000E+00 .000E+00 .000E+00 .000E+00 N/A

.16 (CsI) CsI .678E-09 .142E 06 .443E 01 .852E+00 .103E+00 .310E-02 i

l J

l l

252 y_, s., - - - -

Table 6.1.4 MELCOR predicted fractional distribution of radioactive radionuclides at 511,525 seconds (5.92 days) after containment failure of the SBO wet cavity and Limestone concrete sequence PJLAP MELCOR CAVITY RCS. CONTMN. CONTHN

. CLASS NAME . CORE

.000E+00 .342E+00 .156E+00 .960E+00 1 (Ie) Noble Gas .502E+00 a

.000E+00 400E+00 .858E-01 .127E+00 2 (Cs) Alkali Metal .515E+00

.000E+00 .004E-01 .007E-02 .166E-01 3 (Ba) Alkaline Earths .912E+00

.100E+01 .000E+00 .327E-04 '.411E-04 -N/A 4 (I) Halogens 5 (Te) Chalcogens .928E+00 .000E400 .661E-01 .634E,02- .540E+00

.996E+00 .000E+00 .327E-02 .310E-03 N/A 6 (Ru) Platinoids

.969E+00 .000E+00 .280E-01 .279E-02 .119E-01 7 (Mo) Early Transition

.100E+01 .000E+00 .601E-04 .595E-05 .620E-02 0 (Ce) Tetravalents

.999E+00 .000E+00 .671E-03 419E-04 .992E-03 9 (La) Trivalents

.100E+01 .000E+00 .150E-03 .837E-05 N/A 10 (U) Uranium *

.730E400 .000E+00 .239E+00 .311E-01 .170E+00 11 (Cd) More volatile

.730E+00 .000E+00 .239E+00 .311E-01 N/A 12 (Sa) volatile

.000E+00 .000E+00 .000E+00 .000E+00 N/A 13 (D) Doron an~

.000E400 .000E+00 .000E+00 .000E+00~- N/A l

14 (H2O) Water l

.000E+00 .000E+00 .000E+00 000E+00 N/A l

15 (Conc) Concrete

.670E-07 .000E+00 .833E+00 .167E+00 .990E-01 16 (CsI) CsI i -------........................-..................-..-..--. ...................

5 9 l

253 l

l I

'I Table 6.1.5 Effects of Flooded Cavity for the M LOCA Sequence with Basaltic Concrete Type Dry Cavity Wet Cavity Cavity Water in cavity @ V.B. 3.75 m' 342 m 3 Water in cavity @ Cont. failure 0 283 m 3 CCI H2 Production from CCI @ 24 hr 1,505 kg 1,207 kg Radial abrasion @ 24 hr .71 m .35 m l

Axial abrasion @ 24 hr 2.25 m 1.84 m CCI abrasion @ Cont. failure 4.57 m 3.53 m

. DT required CCI to reach 4.81 br 6.89 br embeded Cont. Shell _

Containment Pressure @ 24 hr 53.5 psia 50.5 psia Temperature @ 24 hr 310 F* 251 F*

Pressure @ Cont. failure 122 psia 155 psia Temperature @ Cont. failure 363 F* 364.4 F Containment failure mode melt-through over pressurization Time of containment failure 3.70 d 6.37 d II 2-burn Location of H 2-burn before V.B. - -

1 cavity, IRWST Location of H 2-burn after V.B. cavity, low, Ann, Upp l

254

I Table 6.1.6 Effects of Flooded Cavity for the S LOCA Sequence with Limestone Concrete Type l

Dry Wet Cavity Water in cavity after V.B. 233 m 3 322 m 3 {

Water in cavity @ Cont. failure 0 275 m 3 CCI H2 Production from CCI 1,166 kg 830 kg Radial abrasion @ 24 hr .49 m .31 m Axial abrasion @ 24 hr 1.88 m 1.52 m CCI abrasion @ Cont. failure 4.53 m 3.58 m DT required CCI to reach 10.49 hr 11.53 hr embeded Cont. Shell -

Containment Pressure @ 24 hr 4.04x105Pa 3.76x105Pa Temperature @ 24 hr 447K 397K 1.068x106Pa 5

Pressure @ Cont. failure 10.68x10 Pa Temperature @ Cont. failure 487K 447K Containment failure mode over pressurization over-pressurization Time of containment failure 4.49 d 5.82 d II-burn 2

Location of H 2-burn before V.B. - -

Location of H2-burn after V.B. cavity, low, Ann, Upp, IRWST compartment 255

Table 6.2.1 Comparison of the Basaltic and Limestone Concrete a

Limestone i

i Basaltic Aggregate-l Species Aggregate Common Sand Species (w/o) No. Concrete Concrete l

SiO 2 1 54.84 35.80 TiO 2 2 1.05 0.18 Mn0 4 0.00 0.03 l

Mg0 5 6.16 0.48 Ca0 6 8.82 31.30 Na0 10 1.80 0.082 2

K02 11 5.39 1.22 18 6.26 1.44 Fe203 A10 19 8.32 3.60 23 22 0.00 0.014 Cr203 CO 2 59 1.50 21.154 H 2O evap 86 3.86 2.70 H 2O chem 87 2.00 2.00 Melting Temperature, K Solidus 1350 1420 Liquidus 1650 1670 6 6

Heat of Fusion J/Kg 1.8x10 1.2x10 i

l l

l l

l 256 l^

l

i Table 6.2.2 Effect of Cavity Concrete Type for the SBO Sequence With Flooded Cavity Limestone Basaltic Cavity Water in cavity @ VB 299 m 3 299 m 3 Water in cavity @ Cont. failure 251 m 3 259 m 3 CCI H2production from CCI 1,140 kg 2,492 kg Radial abrasion @ 24 hr .36 m .31 m 1.35 m 1.90 m Axial abrasion @ 34 hr CCI abrasion @ Cg,t. failure 2.45 m 3.97 m DT required for CCI to reach 11.23 hr 6.78 hr embedded contaiment steel shell*

Containment Pressure @ 24 hr 3.85x105 (56 psia) 3.31x105 Pa (48 psia)

Temperature @ 24 hr. 402 K 392 K Temperature @ Cont. failure 447 K 455 K Containment failure mode over pressurization over pressurization Time of containment failure p=155 5.23 d 5.38 d H 2-Burn Location of H 2-burn before VB IRWST IRWST Location of H2-burn after VB IRWST, Cavity IRWST Low, Ann,Upp Containtment Time measu:cd frota ':e nitiation of CCI ,

257 d

1 Table 6.23 MELCOR predicted . fractional distribution of radioactive  !

radionuclides at 525,141 seconds (0.71 days after containment failure) ,

for the SBO, wet cavity and Basaltic' concrete sequence. -

............................................................... ~..............

CLASS CORE CAVITY RCS CONTMN ENVIRON.

................NAME- ......................................................s........ ,

1 +,

1 (Ie) Noble Gas .782E-04 .000E+00' .136E-03 .288E-04 .100E+01 2 (Cs) Alkali Metal .764E-04 .342E-14 .157E+00 .821E+00 .216E ,l 3 (Ba) Alkaline Earths .470E-02 .560E+00 .819E-01 .353E+00 .391E-06 4 (I) Halogens .971E+00 .000E+00 .917E-06 .676E-06 .285E-01 5 (Te) Chalcogens .469E-02 .' 4 5 8 E+ 0 0 .217E-01 .515E+00 .815E-03 6 (Ru) Platinoids .527E-02 .990E+00 .326E.02 .126E-02 .550E-08

, 7 (Mo) Early Transition .482E-02 .920E+00 .307E-01 .442E-01 .671E 07

~

8 (Ce) Tetravalents .528E-02 .595E+00 .641E-04 .306E-04 .001E-08 .

?

9 (La) Trivalents .528E-02 .985E+00 .474E-03 .924E-02 .645E-08 f 10 (U) Uranium .333E-02 .996E+00 .212E-03 .918E-04 .643E-08 11 (Cd) More volatile .340E.02 .634E+00 .261E+00 .101E+00 .307E-06 12 (Sn) Volatile .340E-02 .611E+00 .261E+00 .124E+00 .271E 05 13 (B) Boron .000E+00 .000E+00 .000E+00 .000E+00 .000E+00 14 .(H2O) Water .000E+00 .000E+00 .000E+00 .000E+00 .000E+00 15 (Cone) Concrete .000E+00 .000E+00 .000E+00 .000E+00 .000E+00 16 (CsI) CsI .170E-09 .385E-06 .117E+00 .849E+00 .342E.01 b

f i

258  :

r

l I l Table 6.2.4 Effect of Cavity Concrete Types for the M.LOCA Sequence on Dry Cavity Limestone Basalt Cavity Water in cavity after V.B. 3.70 m' 3.75 m 3 Water in cavity @ Cont failure 0 0-CCI H 2production from CCI @ 24 hr 871 kg 1,505 kg Radial abraion @ 24 hr .72 m .71 m Axial abrasion @ 24 hr 1.75 m 2.25 m CCI abrasion @ Cont. failure 2.75 m (extrapolated) 4.57 m DT required CCI to reach 8.56 hr 4.81 hr embeded Cont. Shell Containment -

Pressure @ 24 hr 57.7 psia 53.5 psia Temperature @ 24 hr 309 F* 310 F*

Pressure @ Cont. failure 155 psia 122 psia Temperature @ Cont. failure 444 F* (extrapolated) 363 F*

1 Containment failure mode over pressurization melt through* i Time of containment failure 4.48 d (extrapolated) 3.70 d il-burn 2

Location of H 2-burn before V.E. - -

Location of H 2-burn after V.B. cavity, low, Upp, cavity, low, Upp, Ann compartment compartment

• Melt-through does not refer to containment failure l

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I Table 6.2 5 Effects of Cavity Concrete Type for the S LOCA Sequence With a Dry Cavity  ;

i Major Event Limestone Basalt Cavity Water in cavity after V.B. 233 m 3 240 m 3 1

Water in cavity dried-out 31,250s (8.68 hr) 30,500s (8.47 hr) l CCI H 2production from CC1 1,166 kg 2,794 kg Radial abrasion @ 24 hr 0.49 m .57 m Axial abrasion @ 24 hr 1.88 m 2.37 m CCI abrasion @ Cont. failure 4.53 m 4.58 m DT required CCI to reach 10.49 hr 7.01 br embeded Steel Shell*

Containment -

Pressure @ 24 hr 4.04x105Pa 3.54x105Pa Temperature @ 24 hr 447K 442K 6

Pressure @ Cont. failure 1.068x10 Pa 6.11x105Pa Temperature @ Cont, failure 487K 454K Containment failure mode over pressurization melt-through" Time of containment failure 4.49 d 2.75 d Il 2-burn Location of H 2-burn before V.B. - -

Location of H 2-burn after V.B. cavity, low , Ann , cavity, low , Ann ,

Upp- Upp.

l compartment compartment Time is measured from tre initiation of CCI.

Melt-through does not refer to containment failure 260 l

I Table 6.3.1 Effect of Rupture Size in the SGTR Sequence Event 2 Tubes 5 Tubes Accident initiation 0.0 0.0 Reactor trip 0.0 0.0 Core uncovery 3,178s (53,0 min) 347s (5.79 min)

Fuel gap release 47,76s (1.32 hr) 1,312s (21,87 min)

Core dry out 6,336s (1.76 hr) 2,412s (40.20 min)

Core support plate failure 6,977s (1.94 hr) 4,238s (1.18 hr)

SIT inject 8,500s (2.36 br) 4,395s (1.22 hr)

SIT complete 9,500s (2.64 hr) 4,682s (1.30 hr)

Reactor vereel failure 7,543s (2.10 hr) 3,300s (55.0 min)

Commence debris ejection 8,382s (2.34 hr) 3,319s (55.3 min)

Begin concrete attack 8,382 (2.34 hr) 3,319s (55.3 min)

Containment failure 6.31 d (p= 155 psia) 4.92 d (melt through)*

Total H 2in vessel-production 556 kg 780 kg Total H 2CCI production 1,072 kg 1,423 kg CCI radial penetration (24 h) 0.27 m .29 m CCI axial penetration (24 h) m 1.45m CCI reached steel containment 50,000s (13.89 hr) 43,770s (12.16 hr) structure Containment pressure (24 h) 55 psia 68 psia Containment pressure at 155 psia 149 psia containment failure Containment temperature (24 h) 254 F 275 F

• Melt-through does not refer to containment failure i

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7.

SUMMARY

A MELCOR- input deck has been developed for the CE System 80+ Plant. The i J

nodalization contains 44 control volumes,58 flow paths, and 115 structures. We believe that the nodalization represents a reasonable description of the System 80+ RCS and containment. The latest revision of the MELCOR code (version 1.8.2) was used for the analysis.

Four accident sequences were selected for study, namely: station blackout (SBO), small-break LOCA, medium-break LOCA, and steam generator tube rupture (SGTR). Each sequence involves a base case and sensitivity studies. Comparisons with the MAAP results were made for selected cases presented in CESSAR.

For all four base cases, it was assumed that the cavity flooding system was not activated and the cavity basemat was made of limestone concrete. The failure of active safety injection, emergency feed water and containment sprays also were assumed. The SGTR sequence assumed a rupture of 2 tubes. MELCOR analyses show that for all sequences, except the MB-LOCA, the reactor vessel is maintained at pressure levels above the set point of the SITS. Therefore, the SIT is activated only after the vessel fails and the water is added together with any residual water in the reactor vessel into the cavity. Consequently, the

" dry-cavity" cases have about 200 cubic meters of water in the cavity immediately after the-vessel's failure and the water is predicted to boil off in several hours. A rapid ~

depressurization in the reactor vessel was predicted only for the MB-LOCA sequence which leads to the actuation of the SITS before the vessel fails. The SIT water is discharged from the break into the containment and is collected in the IRWST. A dry cavity is maintained during the entire transient for this sequence.

CCI can cause over-pressurization of the containment and melt-through of the cavity basemat. MELCOR predicted that melt-through of the basemat would occur prior to overpressurization failure for the SBO sequence. However, for the MB-LOCA and SGTR sequences MELCOR predicts overpressurization failure prior to basemat melt-through. For the SB-LOCA sequence, the containment failure by overpressurization could occur at about the same time of basemat penetration mechanism. The failure times for the four sequences vary from 4 to 8 days (Table 7.1). An additional scenario was analyzed for the SGTR base case, in which a stuck-open MSSV was assumed. The containment sprays and cavity flooding systems also were assumed available. This scenario is similar to that analyzed by MAAP and reported in the CESSAR. Both codes predicted no containment failure at the end of the calculations (i.e. 40 and 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br /> in the MAAP and MELCOR analyses, respectively).

Sensitivity studies were performed to evaluate the effects of 1) cavity flooding,2) basaltic concrete and 3) rupture size for the SGTR sequence. The following summarizes work:

l

1) A flooded cavity initiated before failure of the vessel reduces the erosion of the cavity l basemat by the core debris. This, in turn, reduces the chance of basemat melt-through, as shown in Table 7.2. A flooded cavity enhances the containment's pressurization by j

adding steam into the atmosphere, and therefore, containment failure occurs by 262 l .

I overpressurization (if CHR is lost) before melt-through of the basemat. Flooding seems to have a stronger effect on basaltic concrete than on limestone concrete. For example, for the MB-LOCA sequence using basaltic concrete, MELCOR predicted that the containment would fail by over-pressurization at about 6.4 days if the cavity is flooded, but that basemat melt-through would occur at about 3.7 days if cavity flooding is not activated. For the SBO sequence using limestone concrete, a flooded cavity causes an early containment failure by over-pressurization (5.23 days), while a dry-cavity results in the melt-through of the cavity basemat later (6.71 days).

2) Basaltic concrete contains considerably less carbon dioxide and slightly more water vapor than limestone concrete. Hence, using basalt could result in more gradual pressurization in the containment. On the other hand, the relatively low melting temperature of the basaltic concrete would cause the concrete to erode faster. Table 7.3. indicates that the erosion rates for basalt concrete are always faster than limestone, but that limestone produces faster pressurization of the containment.

3) The number of tubes ruptured was increased from 2 to 4 and 25 for the SGTR sequence. A limestone concrete and dry cavity were assumed for these scenarios. As expected, the increase of rupture size uncovers the core faster and results in earlier failure of the vessel. The rupture of 2 and 4 tubes is similar to a SB LOCA. The cavity is partially flooded due to activating the SITS immediately after the vessel fails. The-rupture of 25 tubes is similar to a MB-LOCA. The early discharge of the SIT water" results a dry cavity after the vessel's failure. MELCOR predicted a late over-pressurization failure for the 2-tube case, over-pressurization failure and basemat melt-through at about same time for the 4-tube case, and an early basemat melt through for the 25-tube case (summarized in Table 7.3).

MELCOR predicted multiple burns in the containment for all sequences. The multiple burns generate spikes in temperature and pressure in the containment, which do not appear to threaten the containment's integrity. However, for several cases, multiple burns cause the temperature of the containment to be above the design temperature for a relatively long period.

Limited comparisons with the MAAP results show a reasonable agreement for several major events predicted by the two codes. However, MAAP generally predicted a slower erosion of the cavity basemat. This is caused by the differences in modeling corium/ concrete and corium/ water interactions as discussed in Appendix A. These differences lead to different predictions of the two codes.

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R e fe r e n c e . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1. Combustion Engineering Standard Safety Analysis Report-Design certification (CESSAR-DC) Volume 1-25, 1993 l 1

2. MELCOR 1.8.2 Computer Code Manual Volume 1: Primer and User's Guide Volume 2: Reference Manuals and Programmer's Guides, Sandia National Laboratories, February 1993

3. Private Communication Between S. Nimnual of BNL and R. Summers of SNL, March 25,1994.

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as 264 l

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Table 7.1 Summary of Containment Failure Mode and Time for Base Cases  :!

Sequence SBO SB LOCA - M B-LOCA SGTR 2 Concrete limestone limestone limestone limestone Type Cavity no no no no Flooding Containment melt- melt- over- over-Failure (CF) through* through and pressurizati pressurizati Mode over- on on pressurizati on Failure Time, 6.71 4.49 4.48 7.85 days Pressure at 96 155 155 155 CF, psia

~

Concrete 4.57 4.53 2.75 4.0 .

Erosion at CF,m

• Melt-through does not refer to containment failure i

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Table 7.2 Summary of Containment Failure Mode and Time for Sensitivity Studies Involving Cavity Flooding Sequence SBO SB-LOCA MB-LOCA Concrete type limestone limestone Basaltic Cavity flooding no yes no yes no yes Containment melt- over- over- over- melt- over-Failure (CF) through pressurization pressurization pressurization through* pressurization mode CF Time, days 6.71 5.23 4.49 5.82 3.70 6.37 Pressure at CF, 96 155 155 155 122 155 psia Concrete erosion 4.57 2.45 4.53 2.58 4.57 3.53 at CF, m

• Melt-through does not refer to containment failure

Table 7.3 Summary of Containment Failure Mode and Time for Sensitivity Studies Involving Concrete Type Sequence SBO SB-LOCA MB-LOCA Cavity Flooding yes no no Concrete Type basaltic limestone basaltic limestone basaltic limestone Containment over- over- melt- over- Melt- over-Failure (CF) mode pressurization pressurization through* pressurization through* pressurization and Melt-through*

Failure Time, days 5.38 5.23 2.75 4.49 3.7 4.48 Pressure at CF, 155 155 89 155 122 155 psia Concrete erosion 3.97 2.45 4.57 4.53 4.57 2.75 at CF, m

$

• Melt-through does not refer to containment failure

l

! I Table 7.4 Summary of Containment Failure Mode and Time for The SGTR Sequence No. of tube 2 4 25 ruptured Concrete type limestone limestone limestone Cavity Flooding no no. no Containment over-pressurization over-pressurization melt-through*

Failure (CF) mode CF Time, days 7.85 6.31 4.92 Pressure at CF, 155 155 135 psia Concrete erosion 4.0 4.54 4.57 at CF, m

• Melt-through does not refer to containment failure O

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I Appendix A MAAP and MELCOR Modeling of Corium/ Concrete Interaction In a detailed evaluation of the MAAP 3.0B code, Yang [A.1] discussed the physical models used in MAAP 3.0B to simulate corium/ concrete interaction and compared these models with those used in MELCOR. The discussions are summarized in this appendix to illustrate the basic differences between the two codes.

The general treatment of the decomposition of concrete by a molten or solid corium pool is provided by the subroutine DECOMP in the MAAP 3.0B code [A.2]. The CORCON-MOD 2 model which is equivalent to DECOMP, is incorporated in the MELCOR code.

Although DECOMP and CORCON both model the major phenomena related to corium/ concrete interactions, there are significant differences in the assumptions and approximations used.

1. Molten Pool lleat Transfer DECOMP assumes that the molten corium pool is homogeneously mixed. The concrete slag caused by the concrete melting is assumed to enter the debris pools immediately and mix with the core debris. The homogeneously mixed model implies that the debris has a single temperature, that there is uniform heat convection in all directions in the pool, and an equal thickness of the bottom and side crusts. (The top crust is treated separately.) The_

model also finds the same temperature profiles and erosion rates of concrete in both-sideward and downward directions.

In the CORCON model used in MELCOR, a stratification modelis assumed for the molten debris pool. It is assumed that the oxidic species and metallic species in the melt are mutually immiscible. Buoyancy forces are sufficient to separate the molten debris into two phases, even when there is vigorous mixing by gases from the decomposition of concrete.

In addition to the two layers (metal / oxide), CORCON provides another oxidic layer on top of the debris melt. This less dense oxidic layer is composed of ablation concrete oxides and steel oxides produced by chemical reactions with the concrete-decomposition gases.

However, the three-layer configuration (oxide / metal / oxide) is not predicted to last for long.

The bottom fuel-oxide layer diluted by concrete oxides becomes less dense than the metal layer. At this point, it is assumed that the bottom oxide layer moves above the metal layer and forms a single oxide layer. The CORCON model predicts different temperatures in each of the layers in the molten pool, non-uniform heat transfer, and non uniform crust thickness in the sideward and downward directions. Consequently, in CORCON, the rates of concrete decomposition and gas release differ in the downward and the sideward directions.

Sandia (the developer of the CORCON code) cited several experimental findings, A.3, to support the multiple-layer approach. The difference in heat transfer in the sideward and downward direction, (as described by Sandia), is caused by the gas flow between the melt and the concrete. In the downward direction (i.e., on the concrete floor), gas is generated at the boundary and enters the melt, while on the side surfaces, gas forms a flowing film along the boundary of the melt.

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In both DECOMP and CORCON, a quasi-steady model is used to calculate the heat i transfer. In DECOMP, the convective heat loss form the molten debris to its peripheral crust is determined by a heat transfer coefficient specified by the user, i.e., model parameter no.12 HTCMCR. The best estimate, are recommended minimum and maximum values are 1000,500, and 5000 W/m 2-K, respectively. This heat transfer is assumed to be equal in the downward, upward, and sideward directions. In CORCON, the multi-layer model permits the code to compute separate temperatures for each layer, computing the heat transfer to the upper, bottom, and side surfaces by different correlations. The presence of bubble agitation is included in these correlations. The model parameters used in MAAP allow the heat-transfer coefficient to be varied, so as to observe sensitivity to the temperature of the debris. We note that the release of fission products is strongly affected by the latter.

2. EITect of Water Layer Both MAAP and MELCOR allow for a water layer on top of the debris pool in the DECOMP and CORCON subroutines. This water layer is assumed not to interact I

energetically with the molten materials, but rather, serve as an additional heat sink. The presence of a water pool is predicted to cool the top of the melt below the solidification temperature, forming a thin solid curst on the surface.

In Decomp, the corium/ water interaction is determined in subroutine PLSTM. The model-

assumes that the debris crust in contact with water will crack and allow the ingress of water;~

the corium/ water interaction could quench the debris. In CORCON, the possibility of crust cracking and water ingress are not modeled; the overlying water pool is modeled only as a heat sink. The heat-transfer model in CORCON includes the full boiling-curve based on j a standard pool boiling correlation. No correction is made for the effects of gas injection at the melt / water interface. Also, the water pool does not have a significant influence on the temperature of the core debris. In a recent report, Powers et. al. [A.4) stated that "the data base now available on these simultaneous (corium/ concrete / water) interactions does not support the belief that water will quench the core debris"

3. Corium Concrete Contact and IIcat Conduction in Concrete l

One large difference between the DECOMP am CORCON models is the treatment of heat

transfer at the corium-concrete interface and within the solid concrete. When core debris l attacks the concrete, the melt solidifies and the concrete melts at the interface. A thin thermal layer penetrates the solid concrete, within which complex decomposition reactions take place.

l In DECOMP, a direct contact between the core debris and concrete is assumed. The l interface temperature of the debris crust and the concrete is equal to the temperature of

! the concrete's surface, which is the ablation temperature for concrete. (DECOMP assumes that melting of the concrete begins instantaneously upon contact with molten debris.) A one-dimensional heat-conduction calculation is performed by subroutine HTWALL for temperature profiles in the solid concrete. Because the heat flux and temperature profiles are the same both downwards and sidewards, the erosion rate also is the same in these directions.

270 1-i

i CORCON assumes that a stable gas film forms upon initial contact between the molten core debris and concrete. The concrete is separated from the debris by a gas film. The gas film model was modified in CORCON-MOD 2, which is the version used in the current version of MELCOR. It is believed that, under most conditions, gas release usually is far less than is required to form a stable gas film, and instead, intermittent debris / concrete contact occurs. Therefore, an interface temperature model was implemented in the CORCON-MOD 2 code to describe heat transfer at the interface between the core debris and the concrete. The interface temperature predicted by CORCON is closer tothe debris temperature than to the concrete's surface temperature because of higher thermal conductivity of the debris.

The CORCON interface model also includes the melting of the concrete and solidification of the core melt. The concrete slag is removed from the interface into the core melt by rising bubbles. The gas-film model was retained in the code but is only invoked when the gas velocity is sufficiently high.

CORCON does not consider heat conduction into the concrete nor decomposition in advance of the ablation front. Only one-dimensional steady-state ablation is computed.

4. Solid Pool Treatment Both DECOMP and CORCON allow the formation of solidified pool when the crush thickness fills the entire pool. In DECOMP, the treatment of heat transfer in a solidified poolis similar to that in a molten pool. The same heat conduction is calculated for the side walls and the lower bottom wall, resulting in their equal erosion.

The equal concrete-erosion modelin DECOMP is not applicable to a solidified debris pool.

Because of the rigid surfaces of the debris, the molten concrete and released gases are likely to form a film between the debris and the eroded cavity sidewalls. This film represents an additional thermal resistance and would reduce the rate of the erosion of the sidewall.

Furthermore, the newly eroded concrete will not be able to mix with the rest of the debris and will probably be pushed to the top of the debris where it will form a growing crust.

Since the concrete slag crust has no internal heating, it becomes an effective insulating barrier to upward heat transfer. The insulation effect will influence the internal heat-transfer in the solid debris pool. These phenomena are omitted in the DECOMP model.

CORCON predicts a top oxide layer, which is a mixture of core and concrete oxides and thus is internally heated. This treatment, developed for a molten pool, is not valid for a solidified pool.

Another important feature related to solidified debris is mixing and stratification during the transition from a molten to a solidified state. DECOMP assumes there is gross mixing while CORCON assumes there is stratification. For a conduction-limited solid debris, the most important property that affects the heat transfer process is thermal conductivity. Since thermal conductivity for the metallic and oxidic phases differ by at least an order of magnitude, the difference plays an important role in heat transfer in the debris. In the CORCON stratification model, the metallic layer has higher thermal conductivity but a lower decay power source. Hence, the metallic layer may solidify while the oxidic layer 271

I remains molten. The potential for a partially solidified layer and a molten layer can not be modeled by DECOMP.

5. Chemical Reactions In DECOMP, the various oxidation processes are computed by the chemical equilibrium model in the METOXA subroutine. The model allows all reactions to proceed in parallel.

Potential oxidation of chromium, a constitute of stainless steel, is omitted because at present, MAAP's mass balance equation does not include this species.

In MELCOR, the chemical reactions are calculated with the latest version of the chemical equilibrium routine developed for CORCON. An entropy of mixing term is included in the chemical potential of each condensed phase species, whose principal effect is to eliminate the strict sequential oxidation of metallic species. Chromium oxidation is included in MELCOR.

References:

A.1 Yang, J. W., Section 18 Corium-concrete interaction, Appendix A PWR Model Descriptions, MAAP 3.0B Code Evaluation Final Report, BNL Technical Report, FIN L-1499, Brookhaven National Laboratory, October 1992.

A.2 MAAP 3.0B Users Manual, Vol.2, Fauske & Associates, Inc., March 16,1990.

A3 Copus, E. R. and D. R. Bradley, " Interaction of Hot Solid Core Debris with Concrete," NUREG/CR-4558, Sandia National Laboratory, June 1986.

! A.4 Powers, et.al., "Recent Advances in the Study of Core Debris Interactions with Concrete," ANS Transactions, Vol.63,1991, p.261.

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