ML20065E253
| ML20065E253 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 03/31/1994 |
| From: | Kmetyk L, Laura Smith GEO-CENTERS, INC., SANDIA NATIONAL LABORATORIES |
| To: | NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| References | |
| CON-FIN-L-2486 NUREG-CR-6107, SAND93-2042, NUDOCS 9404080073 | |
| Download: ML20065E253 (200) | |
Text
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NUREG/CR-6107 SAND 93-2042 1
' Summary 0:? MELCOR 1.8.2 Calcu..ations :for Three LOCA Secuences (AG, S2D, anc S3D}
at ~:ne Surry Plan ~:
Prepared by L Kmetyk/SNL L Smith /GCI Sandia National Laboratories 3
Operated by Sand;a Corporation Geo-Centers Inc.
l Prepared for l
U.S. Nuclear Regulatory Commission hDR DOC 05 00 80 P
4 esum AVAILABILITY NOTICE Avadabihty of Re erence Matenars Cited in NP.C Pubhcations f
Most documents cited in NRC publications will be available from one of the following sources.
1.
The NRC Public Document Room 2t20 L Street, NW., Lower Level. Washington, DC 20555-0001 The Superintendent of Documents. U S. Government Printing Office, Mail Stop SSOP, Washington DC 2.
20402-9328 3.
The Natonal Technical Inf ormation Service, Spongf:efd, VA 22161 Although the listing that fol!ows represents the majority of documents cited in NRC publications, !t is not in-tended to be exhaustive.
Referenced documents available for inspection and copying for a fee from the NRC Pubhc Document Room include NRC correspondence and internal NRC memoranda; NRC bulletins, circu!ars. Information notices. in-spection and investigation notices; licensee event reports, vendor reports and correspondence: Commission papers: and apphcant and beensee documents and correspondence f orma :
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ef" D!SCLAIMER NOTICE This report was prepared as an account of work sponsored by an agency of the United States Government.
Ne:ther the United States Government nor any agency thereof, or any of their employees, makes any warranty, expressed or implied, or assumes any legal habihty of responsbihty for any third party's use, or the resufts of 4
such use, of any information, apparatus, product or process disclosed in tnis report, or represents that its use by such third party would not infringe pnvately owned rights.
NUREG/CR-6107-SAND 93-2042 e
b Summary of MELCOR 1.8.2 Calculations for Three LOCA Sequences (AG, S2D, and S3D) at the Surry Plant x
6 Manuscript Completed: October 1993 Date Published: March 19%
EYepared by i-L Kmetyk/Sandia National Laboratories L Smith /Geo-Centers In-Sandia National Latx>ratories Albuquerque, NM 87185 Geo-Centers Inc.
2201 Buena Vista Dr. SE Albuquerque, NM 87106 Prepared for Division t,f Safety Issue Resolution Office of Nuclear Regulatory Research U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 NRC FIN L2486
Abstract Activities involving regulatory implementation of updated source term information were pursued. These activities include the identification of the source term, the' identification of the chemical form of iodine in the source term, and the timing of the source term's entrance into containment. These activities are intended to support a more realistic source term for licensing nuclear power plants than the current TID-14844 source term and current licensing assumptions. MELCOR -
calculations were performed to support the technical basis for the updated source term.
This report presents the results from three MELCOR calculations of nuclear power plant accident sequences and preses.ts comparisons with Source Term Code Package (STCP) calculations for the same sequences. The three low-pressure -
sequences were analyzed to identify the materials which enter containment (source terms) and are available for release to the environment, and to obtain timing of sequence everas. The source terms include fission products and other materials such as those generated by core-concrete interactions. All three calculations, for both MELCOR and STCP, analyzed the Surry plant, a pressurized water reactor (PWR) with a subatmospheric containment design.
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Table of Contents
. Abstract.............................................................
...... iii
~ Acknowledgements.................
-........................................ xi 1 Introduction...........
1 1.1 Background and Objectives.......
I 1.2 MELCOR I
'l 1.3 Organization of Report '.
2 PWR Subatmospheric Containment Design 3
3.
2.1 Reactor and Primary System...........
3 2.2 Containment..
3 Accident Sequences 7
3.1 AG Large Break LOCA Sequence...
7-3.2 S2D Small Break LOCA Sequence 7.
7-3.3 S3D Pump Seal LOCA Sequence 4 MELCOR Plant Model.......
8 8-4.1 General Features...
8 4.2 Nodalization..
8 4.3 Plan 1 Model Features 5 Results and Comparisons with STCP 13 j
5.1 General Comments Applicable to All Three Accident Simulations 13 j
13 5.2 AG Sequence 13 5.2.1 Key Events.............
14
' i 5.2.2 Primary System Behavior......
5.2.3 Core Degradation......
14 5.2.4 Containment Response 15 5.2.5 Fission Product Transport and Release to the Environment...........
........, 16 j
17.
5.3 S2D Sequence....
17 5.3.1 Key Events..
5.3.2 Pdmery Fystem Behavior 18 5.3.3 Core Degradation.....
20 5.3.4 Containment Response........
20
........ 21 -
5.3.5 Fission Product Transport and Release to the Environment.
5.4 S3D Sequence
)
5.4.1 Key Events.....
...................22 5.4.2 Primary System Behavior
. 23 -
5.4.3 Core Degradation
........ -24 5.4.4 Containment Response....
5.4.5 Fission Product Transport and Release to the Environment.
25 '
. 6 Summary and Findings.....
....... 180 7 References
.................... 181
-1 List of Figures 2.1 Surry Reactor Vessel..
5 7
2.2 Surry Subatmospheric Containment NUREG/CR-6107 y
-_-----_---_-_._-_m__-__-___
7 I
List of Figures (continued) 4.2.1 MELCOR Nodalization for Primary System..........................
10 4.2.2 MELCOR Nodalization for Containment
................... 11 4.2.3 MELCOR Nodalization for Core.........
12 5.2.1 Primary System Pressures Predicted during AG Sequence 28 5.2.2 Primary System Temperatures, in Downcomer and in Upper Plenum Predicted during AG Sequence..........
............... 29
- 5.2.3 Core Exit Gas Temperatures, in Upper Plenum and in Uppermost Core Cells Predicted during AG Sequence.
30 5.2.4. Reactor Vessel Liquid Levels Predicted during AG Sequence.
31 5.2.5 Integrated Outflows of Liquid, Steam and Hydrogen through the Hot Leg Break Predicted during AG Sequence 32 5.2.6 Integrated Outflows of Liquid, Steam and Hydrogen through the Vessel Breach Predicted during AG Sequence..
33 5.2.7 Core Ring 1 Clad Temperatures Predicted during AG Sequence......
34 5.2.8 Core Ring 2 Clad Temperatures Predicted during AG Sequence....
35 5.2.9 Core Ring 3 Clad Temperatures Predicted during AG Sequence..
36 5.2.10 Core Total Materu Masses Predicted during AG Sequence......
37 5.2.11 Core Fractional Material Masses Predicted during AG Sequence..
38 5.2.12 Lower Plenum Debris Bed Masses Predicted during AG Sequence..
39 5.2.13 Lower Plenum Debris Bed Temperatures Predicted during AG Sequence.
40 5.2.14 Containment System Pressures Predicted during AG Sequence 41 5.2.15 Containment System Atmosphere Temperatures Predicted during AG Sequence.
42 5.2.16 Cavity Steam and Noncondensable Mole Fractions Predicted during AG Sequence..
43 5.2.17 Decay Heat Predicted during AG Sequence l
44 l
5.2.18 Total Cavity Masses in Cavity Predicted during AG Sequence 45 l
5.2.19 Cavity Layer Masses Predicted during AG Sequence..
46 l
5.2.20 Cavity L.ayer Temperatures Predicted during AG Sequence 47 5.2.21 Decay Heat and Chemical Energy in Cavity Predicted during AG Sequence.
48 5.2.22 Cavity Maximum Radius and Minimum Depth Predicted during AG Sequence 49 5.2.23 Gas Generation Predicted in Core and in Cavity during AG Sequence.....
50 5.2.24 Release of Class 1 (Xe) Noble Gas Radionuclides from Fuel in Core and in Cavity l
Predicted during AG Sequence, as Percentage ofInitialInventory in Core.
53 5.2.25 Release of Class 2 (Cs) Alkali Metal Radionuclides from Fuel in Core and in Cavity l
Predicted during AG Sequence, as Percentage ofInitialInventory in Core.
54 j
5.2.26 Release of Class 3 (Ba) Alkaline Earth Radionuclides from Fuel in Core and in Cavity l
Predicted during AG Sequence, as Percentage ofInitialInventory in Core..
55 1
5.2.27 Release of Class 4 (I) Halogen Radionuclides from Fuel in Core and in Cavity Predicted during AG Sequence, as Percentage of Initial Inventory in Core 56 5.2.28 Release of Class 5 (Te) Chalcogen Radionuclides from Fuel in Core and in Cavity Predicted during AG Sequence, as Percentage ofInitialInventory in Core..
57 5.2.29 Release of Class 6 (Ru) Platinoid Radionuclides from Fuel in Core and in Cavity Predicted during AG Sequence, as Percentage of Initial Inventory in Core....
58 5.2.30 Release of Class 7 (Mo) Early Transition Element Radionuclides from Fuel in Core and in Cavity Predicted during AG Sequence, as Percentage of Initial Inventory in Core 59 -
5.2.31 Release of Class 8 (Ce) Tetravalent Radionuclides from Fuel in Core and in Cavity Predicted during AG Sequence, as Percentage ofInitialInventory in Core 60 5.2.32 Release of Class 9 (La) Trivalent Radionuclides from Fuel in Core and in Cavity Predicted during AG Sequence, as Percentage of Initial Inventory in Core 61 5.2.33 Release of Class 10 (U) Uranium Radionuclides from Fuel in Core and in Cavity Predicted during AG Sequence, as Percentage of Initial Inventory in Core.
62 NUREG/CR-6107 y;
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List of Figures (continued)-
'5.2.34 Release of Class 11 (Cd) More Volatile Main Group Radionuclides from Fuel in Core and in Cavity j
Predicted during AG Sequence, as Percentage of Initial Inventory in Core..................... 63
)
5.2.35 Release of Class 12 (Sn) Less Volatile Main Group Radionuclides fmm Fuelin Core and in Cavity Predicted during AG Sequence, as Percentage of InitialInventory in Core '..........
64-4 5.2.36 Distribution of Class I (Xe) Noble Gas Radionuclides in Primary System, Containment and Environment Predicted during AG Sequence, as Percentage of Initial Inventory in Core..................... 65 5.2.37 Distribution of Class 2 (Cs) Alkali Metal Radionuclides in Primary System, Containment and Environment
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Predicted during AG Sequence, as Percentage of Initial Inventory in Core.
66 -
j 5.2.38 Distribution of Class 3 (Ba) Alkaline Earth Radionuclidesin Primary System, Containment and Environment during AG Sequence, as Percentage of InitialInventory in Core........
67 5.2.39 Distribution of Class 4 (1) Halogen Radionuclides in Primary System, Containment and Environment Predicted during AG Sequence, as Percentage of Initial Inventory in Core..................... 68
{
5.2.40 Distribution of Class 5 (Te) Chalcogen Radionuclides in Primary System, Containment and Environment Predicted during AG Sequence, as Percentage of Initial Inventory in Core..................... 69 5.2.41 Distribution of Class 6 (Ru) Platinoid Radionuclides in Primary System, Containment and Environment Predicted during AG Sequence, as Percentage of Initial Inventory in Core..
70 5.2.42 Distribution of Class 7 (Mo) Early Transition Element Radionuclides in Primary System. Containment and Environment Predicted during AG Sequence, as Percentage of Initial Inventory in Core..........
71 5.2.43 Distribution of Class 8 (Ce) Tetravalent Radionuclides in Primary System, Containment and Environment i
Pralicted during AG Sequence, as Percentage of Initial Inventory in Core..................... 72 5.2.44 Distribution of Class 9 (l.a) Trivalent Radionuclides in Primary System, Centainment and Environment Predicted during AG Sequence, as Percentage ofInitialInventory in Core.
73 5.2-.46 Distribution of Class 11 (Cd) More Volatile Main Group Radionuclides in Primary System, Containment and Environment Predicted during AG Sequence, as Percentage ofInitialInventory in Core 75 5.2.47 Distribution of Class 12 (Sn) 1.ess Volatile Main Group Radionuclides in Primary System, Containment and Environment Predicted during AG Sequence, as Percentage of Initial Inventory in Core '...
76 5.2.48 Total Fission Product Mass Released, and Overall Distribution, Predicted during AG Sequence.
77 5.3.1 Primary System Pressures Predicted during S2D Sequence 79 5.3.2 Primary System Temperatures, in Downcomer and in Upper Plenum Predicted during S2D Sequence...... 80 l
5.3.3 Core Exit Gas Temperatures, in Upper Plenum and in Uppermost Core Cells. Predicted during S2D Sequence....
81 5.3.4 Reactor Vessel Liquid Levels Predicted during S2D Sequence 82
- 7 5.3.5 Integrated Outflows of Liquid. Steam and Hydrogen through the Hot leg Break Predicted during S2D Sequence.....
.......83 5.3.6 Integrated Outflows of Liquid, Steam and Hydrogen through the Vessel Breach Predicted during S2D 84 Sequence..
5.3.7 Core Ring 1 Clad Temperatures Predicted during S2D Sequence 85 5.3.8 Core Ring 2 Clad Temperatures Predicted during S2D Sequence 86 5.3.9 Core Ring 3 Clad Temperatures Predicted during S2D Sequence 87 5.3.10 Core Total Material Masses Predicted during S2D Sequence 88 5.3.11 Core Fractional Material Masses Predicted during S2D Sequence 89 5.3.12 Lower Plenum Debris Bed Masses Predicted during S2D Sequence 90 5.3.13 Lower Plenum Debris Bed Temperatures Predicted during S2D Sequence....................
91 5.3.14 Containment System Pressures Predicted during S2D Sequence 92 i
5.3.15 Containment System Atmosphere Temperatures Predicted during S2D Sequence 93 i
5.3.16 Cavity Steam and Noncondensable Mole Fractions Predicted during S2D Sequence
......'94-5.3.17 Containment Dome Steam and Noncondensable Mole Fractions Predicted during S2D Sequence 95 5.3.18 Decay Heat Predicted during S2D Sequence 96 5.3.19 Total Cavity Masses in Cavity Predicted during S2D Sequence..
97 5.3.20 Cavity Layer Masses Predicted during S2D Sequence....
98 j
5.3.21 Cavity Layer Temperatures Predicted during S2D Sequence.....
99 5.3.22 Decay Heat and Chemical Energy in Cavity Predicted during S21) Sequence
...... 100 l
l vii NUREG/CR-6107 l
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List of Figures (continued) 5.3.23 Cavity Maximum Radius and Minimum Depth Predicted during S2D Sequence................. 101 5.3.24 Gas Generstion Predicted in Core and in Cavity during S2D Sequence...................... 102 5.3.25 Release of Class I (Xe) Noble Gas Radionuclides from Fuel in Core and in Cavity Predicted during S2D
........... 104 Sequence, as Percentage of InitialInventory in Core 5.3.26 Release of Class 2 (Cs) Alkali Metal Radionuclides from Fuel in Core and in Cavity Predicted during S2D Sequence, as Percentage of Initial Inventory in Core
. 105 5.3.27 Release of Class 3 (Ba) Alkaline Earth Radionuclides from Fuel in Core and in Cavity Predicted during S2D Sequence, as Percentage of Initial Inventory in Core
.. 106 5.3.28 Release of Class 4 (I) Halogen Radionuclides from Fuel in Core and in Cavity Predicted during S2D
. 107 Sequence, as Percentage of Initial Inventory in Core 5.3.29 Release of Class 5 (Te) Chalcogen Radionuclides from Fuel in Core and in Cavity Predicted during S2D
.. 108 Sequence, as Percentage of Initial Inventory in Core 5.3.30 Release of Class 6 (Ru) Platinoid Radionuclides from Fuel in Core and in Cavity Predicted during S2D
............ 109 Sequence, as Percentage of Initial Inventory in Core 5.3.31 Release of Class 7 (Mo) Early Transition Element, Radionuclides from Fuel in Core and in Cavity Predicted during S2D Sequence, as Percentage of Initial Inventory in Core....
........ I 10 5.3.32 Release of Class 8 (Ce) Tetravalent Radionuclides from Fuel in Core and in Cavity Predicted during S2D Sequence, as Percentage of Initial Inventory in Core
. 111 5.3.33 Release of Class 9 (La) Trivalent Radionuclides from Fuel in Core and in Cavity Predicted during S2D Sequence, as Percentage of Initial Inventory in Core
................. 112 5.3.34 Release of Class 10 (U) Uranium Radionuclides from Fuel in Core and in Cavity Predicted during S2D Sequence, as Percentage of Initial Inventory in Core
............. I 13 5.3.35 Release of Class 11 (Cd) More Volatile Main Grou; Gdionuclides from Fuel in Core and in Cavity Predicted during S2D Sequence, as Percentage of Initial Inventory in Core
......... I 14 5.3.36 Release of Class 12 (Sn) 1.ess Volatile Main Group Radionuclides from Fuel in Core and in Cavity Predicted -
during S2D Sequence, as Percentage of Initial Inventory in Core.
. 115 5.3.37 Distribution of Class 1 (Xe) Noble Gas Radionuclides in Primary System, Containment and Environment Predicted during S2D Sequence, as Percentage of Initial Inventory in Core
...... I 16 5.3.38 Distribution of Class 2 (Cs) Alkali Metal Radionuclides in Primary System, Containment and Environment Prdicted during S2D Sequence, as Percentage of InitialInventory in Core
........ I 17 5.3.39 Distribution of Class 3 (Ba) Alkaline Earth Radionuclides in Primary System, Containment and Environment -
during S2D Sequence, as Percentage of Initial Inventory in Core......
..............I18 5.3.40 Distribution of Class 4 (I) Halogen Radionuclides in Primary System, Containment and Environment Predicted during S2D Sequence, as Percentage of Initial Inventory in Core
......... I 19 5.3.41 Distribution of Class 5 (Te) Chalcogen Radionuclides in Primary System, Containment and Environment Predicted during S2D Sequence, as Percentage of Initial Inventory in Core
.......... 120 -
5.3.42 Distribution of Class 6 (Ru) Platinoid Radionuclides in Primary System, Containment and Environment Predicted during S2D Sequence, as Percentage ofInitialInventory in Core
....... 121 5.3.43 Distribution of Class 7 (Mo) Early Transition Element Radionuclides in Primary System, Containment and Environment Predicted during S2D Sequence, as Percentage of InitialInventory in Core.......
122 5.3.44 Distribution of Class 8 (Ce) Tetravalent Radionuclides in Primary System, Containment and Environment Predicted during S2D Sequence, as Percentage of InitialInventory in Core
.......... 123 5.3.45 Distribution of Class 9 (La) Trivalent Radionuclides in Primary System, Containment and Environment Predicted during S2D Sequence, as Percentage of Initial Inventory in Core
..........,. 124 5.3.46 Distribution of Class 10 (U) Uranium Radionuclides in Primary System, Containment and Environment Predicted during S2D Sequence, as Percentage of InitialInventory in Core
............ 125 5.3.47 Distribution of Class 11 (Cd) More Volatile Main Group Radionuclides in Primary System, Containment and Environment Predicted during S2D Sequence, as Percentage ofInitialInventory in Core
. 126 5.3.48 Distribution of Class 12 (Sn) Less Volatile Main Group Radionuclides in Primary System, Containment and Environment Predicted during S2D Sequence, as Percentage of InitialInventory in Core........... 127 5.3.49 Total Fission Product Mass Released, and Overall Distribution, Predicted during S2D Sequence 12E 5.4.1 Primary System Pressures Predicted during S3D Sequence 130 NUREG/CR-6107 viii I
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List of Figures (continued)-
. 5.4.2 Primary System Temperatures, in Downcomer and in Upper Plenum, Predicted during S3D Sequence..... 131
. 5.4.3 Core Exit Gas Temperatures, in Upper Plenum and in Uppermost Core Cells Predicted during S3D Sequ ence.......,..................................................... 13 2 5.4.4 Reactor Vessel Liquid Levels Predicted during S3D Sequence
...-......... 133 l
5.4.5 Integrated Outflows of Liquid, Steam and Hydrogen through the Hot Leg Break Predicted during S3D -
l Sequence
.. 134-5.4.6 Integrated Outflows of Liquid, Steam and Hydrogen through the Vessel Breach Predicted during S3D Sequence.............
. 135 5.4.7 Core Ring 1 Clad Temperatures Predicted during S3D Sequence
.......... 136
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5.4.8 Core Ring 2 Clad Temperatures Predicted during S3D Sequence
............... 137 5.4.9 Core Ring 3 Clad Temperatures Predicted during S3D Sequence
.............. 138 5.4.10 Core Total Material Masses Predicted during S3D Sequence
.......... 139 5.4.11 Core Fractional' Material Masses Predicted during S3D Sequence
.............. 140.
5.4.12 Lower Plenum Debris Bed Masses Predicted during S3D Sequence....
............ 141 5.4.13 Lower Plenum Debris Bed Temperatures Predicted during S3D Sequence..................... 142 5.4.14 Containment System Pressures Predicted during S3D Sequence.........
...... 143 5.4.15 Containment System Atmosphere Temperatures Predicted during S3D Sequence
............ 144 5.4.16 Cavity Steam and Noncondensable Mole Fractions Predicted during S3D Sequence
.145 5.4.17 Containment Dome Steam and Noncondensable Mole Fractions Predicted during S3D Sequence 146-
' 5.4.18 Decay Heat Predicted during S3D Sequence 147 5,4.19 Total Cavity Masses in Cavity Predicted during S3D Sequence......
. 148 5.4.20 Cavity Layer Masses Predicted during S3D Sequence.................
... 149 5.4.21 Cavity Layer Temperatures Predicted during S3D Sequence.
.. 150 5.4.22 Decay Heat and Chemical Energy in Cavity Predicted during S3D Sequence
............... 151 e
5.4.23 Cavity Maximum Radius and Minimum Depth Predicted during S3D Sequence....,
...... 152 5.4.24 Gas Generation Predicted in Core and in Cavity during S3D Sequence
......... 153 5.4.25 Release of Class 1 (Xe) Noble Gas Radionuclides from Fuel in Core and in Cavity Predicted during 3D '
Sequence, as Percentage of Initial Inventory in Core
.......-155 5.4.2.6 Release of Class 2 (Cs) Alkali Metal Radionuclides from Fuel in Core and in Cavity Predicted during S3D
.............. 15 6 -
Sequence, as Percentage of Initial Inventory in Core 5.4.27 Release of Class 3 (Ba) Alkaline Earth Radionuclides from Fuel in Core and in Cavity during S3D Sequence, i
,l as Percentage of Initial Inventory in Core...............
...... 157 5.4.28 Release of Class 4 (1) Halogen Radionuclides from Fuel in Core and in Cavity Predicted during S3D Sequence, as Percentage of Initial Inventory in Core................................. 158
' 5.4.29 Release of Class 5 ('"e) Chalcogen Radionuclides from Fuel in Core and in Cavity Predicted during S3D Sequence, as Percentage of Initial Inventory in Core
.....................159 5.4.30 Release of Class 6 (Ru) Platinoid Radionuclides from Fuel in Core and in Cavity Predicted during S3D Sequence, as Percentage of Initial Inventory in Core
................. 160 5.4.31 Release of Class 7 (Mo) Early Transition Element Radionuclides from Fuel in Core and in Cavity Predicted during S3D Sequence, as Percentage of Initial Inventory in Core........
. 161 5.4.32 Release of Class 8 (Ce) Tetravalent Radionuclides from Fuel in Core and in Cavity Predicted during S3D Sequence, as Percentage of Initial Inventory in Core
....... 162 5.4.33 Release of Class 9 (La) Trivalent Radionuclides from Fuel in Core and in Cavity Predicted during S3D Sequence, as Percentage of Initial Inventory in Core
......... 163 5.4.34 Release of Class 10 (U) Uranium Radionuclides from Fuel in Core and in Cavity Predicted during S3D Sequence, as Percentage of Initial Inventory in Core
....... 164 5.4.35 Release of Class 11 (Cd) More Volatile Main Group Radionuclides from Fuel in Core and in Cavity Predicted during S3D Sequence, as Percentag3 of Initial inventory in Core
..........._... 165 5.4.36 Release of Class 12 (Sn) Less Volatile Main Gre.ip Radionuclides from Fuelin Core and in Cavity Predicted during S3D Sequence, as Percentage of InP. sal Inventory in Core...
.,...... 166 5.4.37 Distribution of Class 1 (Xe) Noble Gas Radionuclides in Primary System. Containment and Environment Predicted during S3D Sequence, as Pe-centage of Initial Inventory in Core 167 ix NUREG/CR-6107
List of Figures (continued) 5.4.38 Distribution of Class 2 (Cs) Alkali Metal Radionuclides in Primary System, Containment and Environment Predicted during S3D Sequence, as Percentage of laitial Inventory in Core 168 5.4.39 Distribution of Class 3 (Ba) Alkaline Earth Radionuclides in Primary System, Containment and Environment during S3D Sequence, as Percentage of Initial Inventory in Core......................... 169 5.4.40 Distribution of Class 4 (I) Halogen Radionuclides in Primary System, Containment and Environment Predicted during S3D Sequence, as Percentage of Initial Inventory in Core 170 5.4.41 Distribution of Class 5 (Te) Chalcogen Radionuclides in Primary System, Containment and Environment Predicted during S3D Sequence, as Percentage of Initial Inventory in Core 171 5.4.42 Distribution of Class 6 (Ru) Platinoid Radionuclides in Primary System, Containment and Environment -
Predicted during S3D Sequence, as Percentage of Initial Inventory in Core 172-5.4.43 Distribution of Class 7 (Mo) Early Transition Element Radionuclides in Primary System, Containment and Environment Predicted during S3D Sequence, as Nrcentage of Initial Inventory in Core........... 173 5.4.44 Distribution of Class 8 (Ce) Tetravaient Radionuclides in Primary System. Containment and Environment Predicted during S3D Sequence, as Percentage of Initial Inventory in Core 174
- 5.4.45 Distribution of Class 9 (La) Trivalent Radionuclides in Primary System, Containment and Environment Predicted during S3D Sequence, as Percentage of Initial Inventory in Core 175 5.4.46 Distribution of Class 10 (U) Uranium Radionuclides in Primary System, Containment and Environment Predicted during S3D Sequence, as Percentage of Initial Inventory in Core
... 176 5.4.47 Distribution of Class Il'(Cd) More Volatile Main Group Radionuclides in Primary System, Containment and Environment Predicted during S3D Sequence, as Percentage of InitialInventory in Core........ 177 5.4.48 Distribution of Class 12 (Sn) Less Volatile Main Group Radionuclides in Primary System, Containment and Environment Predicted during S3D Sequence, as Percentage of InitialInventory in Core........... 178 5.4.49 Total Fission Product Mass Released, and Overall Distribution, Predicted during S3D Sequence....... 179 List of Tables 4.2.1 MELCOR RN Classes and InitialInventories 9
l 5.2.1 Sequence of Events Predicted during AG Sequence, Compared to STCP........
27 5.2.2 Radionuclide Distribution in Core, RCS and Cavity Predicted at 5,000 min for AG Sequence 51 l
5.2.3 Radionuclide Distribution in Containment and Environment Predicted at 5,000 min for AG Sequence......-52 5.3.1 Sequence of Events Predicted during S2D Sequence, Compared to STCP 78 l
5.3.2 Radionuclide Distribution at 833 min for S2D Sequence..........
............ 103 t
5.4.1 Sequence of Events Predicted during S3D Sequence, Compared to STCP
.........-129 5.4.2 Radionuclide Distribution at 1,668 min for S3D Sequence...
.154 r
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Acknowledgements The authors would like to acknowledge a number of individuals who contributed significantly to this report. He MELCOR -
development team (Sam Thompson, Randy Cole, Russ Smith and Randy Summers) provided substantial assistance with these -
calculations, including correcting coding errors and identifying input errors, Sam Thompson also provided user-convenient -
plot programs. Susan Dingman and Tom Brown provided the final, formal technical review, which resulted in a large number of improvements and clarifications to the text,
.I i
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1 Introduction L
1.1 Background and Objectives
'l as report 'is designed to satisfy the documentation Activities involving regulatory implementation of updated requirements of FIN. L2486 (Surry MELCOR source term information were pursued. These activities calculations) performed for the U.S. Nuclear Regulatory include the identification of the source term, the Commission (NRC) by Sandia National Laboratories identification of the chemical form of iodine in the source (SNL). He purpose of the report is to compare the term, and the timing of the source term's entrance into results of three STCP analyses of Surry accident containment. These activities are intended to support a sequences carried out by Battelle Memorial Institute more realistic source term for licensing nuclear power (BMI) for the NUREG-1150 program with new analyses plants than the current TID-14844 source term and current of the same accident sequences using MELCOR.
licensing assumptions.
MELCOR calculations were performed to sepport the technical bias for the updated 1.2 MELCOR source term.
MELCOR: began development in 1982 as a fully This report summarizes the results from three MELCOR integrated, engineering-level computer code that models calculations of nuclear power plant accident sequences and the progression of severe accidents in light water reactor TID-14844 presents comparisons with Source Term Code nuclear power plants. MELCOR is being developed at Package (STCP) calculations for the same sequences.'
Sandia National Laboratories for the U.S. Nuclear The program task was to run the MELCOR program tor Regulatory Commission as a second-generation plant risk three low-pressure sequences to identify the materials assessment tool and the successor to the Source Term which enter containment (source terms) and are available Code Package he entire spectrum of severe accident 8
for release to the environment, and to obtain timing of phenomena, including reactor coolant ' system and sequence events.
The source terms include fission containment thermal-hydraulic response, core _ heatup, products and other materials such as those generated by degradation and relocation, and fission product release core-concrete interactions. All three calculations, with and transport, is treated in MELCOR in a unified both MELCOR and STCP, analyzed lossmf-coolant framework for both boiling water reactors and pressurized accidents (LOCAs)in the Surry plant, a pressurized water water reactors. MELCOR has been especially designed reactor (PWR) with a subatmospheric containment design.
to facilitate sensitivity and uncertainty analyses. Its current uses include estimation of severe accident source In the AG sequence, a large break LOCA, both psssive terms and their sensitivities and uncertainties in a variety and active Emergency Core Cooling System (ECCS) of applications.
]
safety systems for protection of the primary systern were assumed to be available until containment failure The newest version of MELCOR, MELCOR 1.8.2, was occurred. Containment protective systems available for released in May 1993. The Surry analyses documented in use included the containment fan coolers and containment this report were carried out with that release version.
sprays. Since the containment recirculation spray system coolers were inoperable, there _ was no capability for (This report assumes a reader having some familiarity containment heat removal as the accident progressed. For with MELCOR' terminology and capabilities. For those f
the small break LOCA's, S2D and S3D, the ECCS with little or no previous experience with M ELCOR, Ref.
systems were assumed unavailable, with the exception of 2 is recommended as a good intnxiuction and source of the passive accumulators.
For those two accident background information.)
sequences, the containment spray systems were fully operable, including the capability for containment heat 1.3 Organization of Report removal via the containment spray recirculat on system coolers. Since each of the-three accident sequences Section 2 contains a brief description of the Surry PWR progressed through core melt, core slumping, reactor with subatmospheric containment design. The AG, S2D, vessel failure, and ex-vessel core-concrete mteractmn, and S3D accident sequences are summarized briefly in they provided a good test of the ability of MELCOR t Section 3.
Section 4 describes the MELCOR model, simulate integrated accidents that progressed to the point along with features particular to the given accident.
of radionuclide release to the containment or environment.
sequences being analyzed. Results' of the MELCOR 3
+ -,,
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Introduction calculations, along with comparisons to the STCP results, are presented in Section 5, for each of the three accident sequences.' Section 6 contains a brief summary and
- conclusions.-
i i
i
~ NUREG/CR-6107 y
m
2 PWR SubatmoSpheric Containment Design The MELCOR analyses described in this volume were condensate storage tank (CST). The Emergency Core based on the Surry Power Station, Unit 1. Operated by Cooling System is a suite of systems designed to deliver the Virginia Electric Power Company, it is located on the coolant water to the reactor vessel in the event of a kmes River in southeastern Virginia, about 16 kilometers LOCA. The ECCS provides makeup water during small (10 miles) south of Williamsburg, Virginia. Two units break accidents when the RCS remains at a relative high are located on the site, with Unit 2 essentially identical to pressure via three High Pressure Injection System (HPIS)
Unit 1.
pumps. These pumps serve as charging pumps under normal operative conditions. For larger breaks in the 2.1 Reactor and Primary System RCS, the Low Pressure Injection System (L.PIS) is available to provide high volume, low pressure coolant The nuclear reactor of Surry Unit 1 is a 2441 MWt flow to the RCS. Both the HPIS and the LPIS can pressurized water reactor (PWR) designed and built by function in a recirculation mode as well as in an injection Westinghouse. The Reactor Coolant System (RCS) is a mode. In the recirculation mode they take suction from three loop design, with a reactor coolant pump (RCP) and the containment sump. Surry also has three passive o U-tube steam generator (SG) in each loop. In addition, accumulators to provide immediate, high flow, low Loop C contains the primary system pressurizer. Under pressure injection to the RV in the case oflarge breaks in normal operating conditions, the RCS operates at ~ 15.5 the RCS.
MPa (155 bar, 2,250 psia), with a core inlet coolant temperature of 557 K (5435 and a core exit coolant 2.2 Containment temperature of 593 K (608'F) The RCS coolant flow mte during normal operation is 12,688 kg/s (27,972 lb/s).
The Surry containment, designed and built by Stone and Webster, is a reinforced concrete cylinder with a The reactor vessel (see Figure 2.1) contains the core, core hemispherical dome. Figure 2.2 shows a cross section of barrel, core support structures, and control rod and the containment.
The cylindrical portion of the instrumentation component structures. Water from the containment sits on a basemat that is 3.05 m (10 ft) thick.
SGs is pumped through the cold legs by the RCPs to the The wall of the cylinder is about 1.3 m (4.3 ft) thick.
reactor vessel (RV) inlet nozzles, transitting the The dome thickness is about 0.8 m (2.6 ft). A welded downcomer and RV lower plenum prior to passing steel liner forms the pressure boundary. Containment through the lower core support plate and entering the volume is 50,971 m' (1,800,000 ft'), and the design core. Moving upward through the core, the coolant flows pressure is 0.41 MPa (4.1 bar,45 psig. 59.7 psia). Due out the top and exits the RV via the outlet nozzles, to conservatisms in design and construction, most flowing through the hot legs into the steam generators estimates of the failure pressure are between two and again. The reactor core is made up of 32,028 Zirealoy-4 three times the design pressure. For the MELCOR clad fuel rods containing sintered UO distributed in 157 analyses, a containment failure pressure of 0.97 MPa (9.7 2
fuel assemblies. The core. ctive height is 3.66 m (12 ft),
bar,126 psig,140.7 psia) was used, which identical to RCS overpressure control is assured by three safety the mean value used for the calculations done for the valves set to open at a nominal pressure of 17.24 MPa Surry plant in support of NUREG-11504and documented (172.4 bar,2,500 psia). Capacity of each safety valve is in the supporting document.'
36.3 kg/s (80 lb/s). Two Power Operated Relief Valves (PORVs) are available, set to relieve RCS pressure when During normal operation, the interior of the containment it reaches 16.2 MPa (162 bar, 2,350 psia). PORV is maintained at about 0.07 MPa (0.7 bar,10 psia),
nominal relief capacity is 22.6 kg/s (49.7 lb/s).
Normal containment cooling is by fan coolers, These are not safety grade, and they will be partially submerged if Safety grade emergency systems are designed to protect the containment sump is full of water. Emergency the RCS in the event of an accident. Should normal containment beat removal is accomplished by the spray feedwater flow be lost, the auxiliary feedwater system systems. The containment spray injection system (SCIS)
(AFWS) is available to provide coolant to the steam has two trains, each with one pump which takes suction generator secondaries. The AFWS has three pumps: two from the Refueling Water Storage Tank (RWST). There cre driven by electric motors; the third is driven by a are two containment spray recirculation systems (CSRS),
steam turbine. The AFWS takes suction from the each with two trains. Each of the six containment spray 3
. - - ~.. _ - _...
i U
PWR trains is independent of the other spray systems, except There is no connection between the containment sump and that each requires electrical power for the pumps. Each the reactor cavity at a low elevation in the Surry containment spray recirculation train includes a heat containment. Water from a pipe break in containment exchanger that is cooled by the service water system and will flow to the sump, The reactor cavity will remain dry a pump that takes suction directly from the containment unless the containment sprays operate.
sump..One system has its pumps located inside the
- containment and the other has its pumps located outside the containment.
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3 Accident Sequences l
l The accident sequences analyzed with MELCOR and 3.2 S2D Small Break LOCA Sequence i
documented in this report are described using the nomenclature originally defined in the Reactor Safety This accident soquence was initiated by a 0.05 m (2 in)
Study, also referred to as WASH-1400.* The AG diameter break in the Loop A bot leg. The AFW system
{
accident refers to a large break loss of coolant accident, was available indefinitely, but all active ECCS systems, l
and the S2D and S3D accidents refer to small break i.e., HPIS and LPIS, were unavailable for injection to the LOCA's, as per the WASH-1400 accident namins primary system. Primary system passive accumulators convention, all initiated when the reactor is at full power.
were functional. Once they were discharged, boiloff of The accident sequences are defined in the following the primary system inventory progressed through core paragraphs.
uncovery, core melting, and vessel breach. Containment Engineered Safety Features (ESF), containment coolers 3.1 AG Large Break LOCA Sequence and containment sprays, were available from the start of the accident. The containment coolers were operating at The AG accident sequence analyzed with MELCOR was the beginning of the accident, shifting to high capacity characterized by a 0.74 m (29 in) diameter break in the when the containment temperature reached 313.7 K Loop A hot leg combined with loss of containment heat (105'F). When containment pressure rose to the 0.172 removal capability, but with all the other safety systems MPa (1.72 bar,25 psia) setpoint, the containment coolers operational.
Additionally, the Auxiliary Feedwater shut down, and t.he containment sprays began injecting System (AFW) remained in operation throughout the water drawn from the RWST. With RWST depletion, the accident, and the steam generator secondarie= were containtnent spray system shifted to recirculation mode, depressurized to a target pressure of 1.31 MPa (13.1 bar, drawing water from the containment sumps and passing it 190 psia) by the operators, starting at 30 min. At the through the containment spray recirculation coolers prior beginning of the incident, the normal containment cooling to spraying it back into the containment atmosphere, system (fan cooling system) was operating but tripped off Operator depressurization of the steam generator within a few seconds due to the rise in containment secondaries to a pressure of 1.31 MPa (13.1 bar,190 pressure above the 0.172 MPa (1.72 bar, 25 psia) psia) began at 30 min, with completion scheduled for 60 serpoint.
The Containment Spray injection System min. The primary system was depressurized by the initiated based on this same 0.172 MPa setpoint, operators when the core exit gas temperature reached 922 j
delivering water from the Refueling Water Storage Tank K (1,200 F).
through the spray nozzles located in the containment dome and reducing containment pressure in the process.
3.3 S3D Pump Seal LOCA Sequence Concurrently, the passive accumulators and the active ECCS components, the High Pressure' Injection System This accident sequence was initiated by a very small and Low Pressure Injection System, provided cooling break, characterized as a pump seal LOCA, with a total water to the core.
The combined action of the leak rate at normal operating conditions of 2,839 liters per containment sprays and ECCS led to rapid depletion of min (750 gpm). For the MELCOR run, all three primary _
the RWST and consequent switchover to recirculation system loops were given breaks sized to produce leakage mode. From that point onward, with the Containment flows of 946.3 liters per min (250 gpm) at normal system Recirculation Spray System (CSRS) coolers inoperable, pressure.
All other pertinent accident sequence the containment pressure began to rise slowly toward the characteristics were identical to those specified for the containment failure point. Upon containment failure, the S2D sequence described in Section 3.2.
ECCS systems ceased operation and boiloff of the remaining inventory commenced, leading to core uncovery, core melting, and vessel breach. When the core exit gas temperature reached 922 K (1,200 F), the operators manually opened the primary system power operated relief valve (PORV), although, by that point, the primary system was already depressurized.
4 MELCOR Plant Model 4.1 General Features The cavity under the reactor vessel was specilied to have t.n internal depth and radius of 1,00 m and 4.28 m, Our MELCOR Surry model was developed from a MELCOR input deck originally received from the Idaho and 3,04 m thick below the cavity.
National Engineering laboratory". (INEL), which m. turn was based on a SCD AP/RELAP5 input deck developed by The hydrogen combustion model.m MELCOR was INELS and subsequently modified by a Sandia National activated, with all default input settings used. Therefore, Laboratories analyst for use in station blackout sequence the hydrogen and oxygen mole fraction limits for igmtion calculations."J2 For the analyses documented in this 5" *" **Y report, that deck was modified further, from a single loop respectively, while the combmed H O and CO mole 2
2 to a three loop model. ECCS active and passive systems fracti n imit f r inerting v lumes with excessive diluents models were added, along with containment Engineered was taken as 0.55.
Safety Features models.
Furthermore, models were created to simulate intentional depressunration of the The default. classes in the MELCOR RN and DCH steam generator secondaries and manual depressurization g
of the pnmary system when the core exit gas temperature MELCOR fission product material classes, including the reached a specified salue.
total radioactive mass inventory of each class tmtially present; a small fraction of these were specified to be in 4,2 Nodalization the gap rather than in the fuel. These calculations were done using the CORSOR fission product release model.
The MELCOR Surry model for these calculations is made These analyses also were done specifying two MAEROS up of 33 control solumes (6 for the reactor vessel and components, one for the water (Class 14) and another for
.l intemals,16 for the primary system loops, 4 for the all other aerosols and fission product vapors, and the steam generator secondaries, 6 for the containment, and default number (five) of aerosol distribution size bins and.
I for the environment); 67 flow paths (51 intemal to the size bin diameters.
RCS 10 internal to the containment, 5 connecting the RCS to containment, and I linking the containment to the A large number of control functions (435) were used to
.I environment); and 143 heat structures (114 for the RCS track the source term telease and subsequent distribution.
and 29 for the containment). Figure 4.2.1 and 4.2.2 give to determine timing and flow of various AFW, ECCS and j
a graphic representation of the basic nadalization used for spray systems, and to adjust. valves and pumps.as the primary system and for the containment, respectivel),
required, In particular, control functions were used to of the Surry plant: note that time-specified control track the total and radioactive masses of each class (1) volumes representing SG feedwater and AFW sources and released from the intact fuel and/or debris in the vessel sinks, and the environment outside containment, are not (either in the core, the bypass or in the lower plenum),
shown in these figures, for simplicity-(2) released from the debris in the cavity, (3) remaining in the primary system (i.e., the reactor vessel), (4) in the All control volumes were specified to use nonequilibrium containment, and (5) in the environment. Those control j
thermodynamics and were specified to be vertical functions provided time-dependent source term release and j
volumes; all heat structures used the steady-state distnbution data for subsequent pcetprocessing in a form temperature-gradient self-initialization option. Detailed more convenient for analysis and evaluation.
volume-altitude tables and junction flow s gments were used to correctly represent subcomponents in and between 4.3 Plant. Model Features the major components modelled.
MELCOR is sufficiently flexible to allow creation of as Nodalization of the reactor core, a separate model from detailed a model as necessary in order to analyze the the control volumes listed above, consists of 39 core cells accident sequences in a realistic way, The AG accident divided into 3 radial rings and 13 axial levels. Axial levels 4 through 13 make up the active core region, while
- sequence required the most complicated input deck., since both primary ECCS and containment ESF systems were levels I through 3 model the lower plenum, including the i
in operation at i,ome point in the calculation. Sufficient core cupport plate in level 3. Figure 4.2.3 illustrates the modeling input was included to model properly the High reactor core nodalization used.
Pressure Injection System (HPIS), the High Pressure i
i MELCOR Plant Model Recirculation System (HPRS), the Low Pressure injection Sources and sinks were utilized to model the Auxiliary i
System (LPIS), and the Low Pressure Recirculation Feedwater System. Control function logic models were System (LPRS) Detailed modeling of the primary system included to model operator depressurization of the steam passive accumulators was included in the station blackout generator secondaries at a time of choice, and to model '
deck. Models were furnished to simulate the Containment operator depressurization of the primary system via the -
Spray Injection System (CSIS) and the Containment Spray Power Operated Relief Valve (PORV) when the core exit Recirculation System (CSRS), including the capability for gas temperature reached 922 K'(1,200"F).
Finally. -
simultaneous operation. The containment coolers were -
control function logic was included to allow the operators modeled for both the normal and enhanced operating to shift delivery of ECCS wa'er from the cold legs to the modes.
hot legs at the 16 hr mark, as assumed in the AG accident sequence.
Table 4.2.1 MELCOR RN Classes and InitialInventories Class Total Class Name Representative Member Elements Radioactive Mass, (Kg)
- 1. Noble Gases Xe He. Ne, Ar, Kr. Xe, Rn, H, N 2.4483E 4 02 4
- 2. Alkali Metals Cs Li, Na, K, Rb Cs, Fr, Cu 1.3645E + 02
- 3. Alkaline Earths Ba Be, Mg, Ca, Sr. Ba, Ra, Es, Fm 1.0740E + 02
- 4. Halogens 1
F. Cl,. Br, I, At 1.0545E + 01 -
- 5. Chalcogens Te O. S, Se, Te, Po.
2,.1481E + 01
- ** ' ' ^ " '
- 6. Platinoids Ru l.5110E + 02 Ni V, Cr, Fe, Co Mn, Nb, Mo, Tc,
- 7. Early Transitwn Elements M
l.7819E + 02 To W 6"'
P' "'
- 8. Tetravaients Ce 3.1440E +02 C
Al, Sc, Y La, Ac, Pr, Nd, Pm,
- 9. Trivalents La Sm, Eu, Gd, Tb, Dy, Ho, Er, 2.9170E + 02 Tm, Yb, Lu, Am, Cm, Bk, Cf
- 10. Uranium U
'U 6.1025 E + 04 '
j
'l 11, More Volatile Main Group Cd Cd, Hg, Zn, As, Sb, Pb, TI, Bi 7.1350E-01
- 12. Less Volatile Main Group Sn Ga, Ge, In, Sn, Ag 4.0521 13, Boron B
B, Si, P 0
- 14. Water
- 1:0 HO O
2
- 15.. Concrete
'O 1
9 NUREG/CR-6107 l
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1
MELCOR Plant Model 11S05002 HSO9007 CV050 (Dome)
HS05003 HS05001 FLOO5 FLO46d N
IIS05014 HSO9006 HS03003 HS05034 NFLO22M O 007
- HS05054, HS05006 11S04101 HSO4003 HSO9003 IIS02002 IIS00501
- V041 :(Przr Cubi) FLO45 CV020 (SG Cubi: -
t HS02001 11S09001 FLD43 Y FLO12 IIS00505 IIS01004 1
HS01005 HSO9002 CV005 (Dasement)
~
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IIS01001 11S01002 HS01003 ifs 00503 Figure 4.2.2 MELCOR Ncxlalization for Containment i
)
- l, p.;
'i
' MELCOR Plant Model w;
~ 6.72197m -
.i Level 13 6.35621m -
-i Level 12 2
5.99045m.
Level 11 5.62469m '
Level 10 5.25893m -
t Level 9 l
4.89317m Level B 4.52741m Level 7 4.18165m -
Level 6 3.79589m Level 5-3.43013m.
e Level 4
.' 3.064 37m Leyel 3 3.01992m Level 2
'1.74550m '-
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1 Figure 4.2.3 MELCOR Nodalization for Core NUREG/CR-6107 '
12 j
,. -..._. -. a.,.. -.
a.
5 ReSults and Comparisons with STCP 5.1 General Comments Applicable to predicted 25.1 min, while MELCOR predicted 1.0 min.
All Three Accident Simulations MELCOR predicted HPIS and LPIS injection to beginjust 0.4 min after accident initiation. Since the primary active ECCS systems, with their high 11ow rates, initiated early For each. f the accident. sequences simulated with o
in the accident, the timing of the passive accumulator MELCOR, the fuel release model selected was CORSOR delivery is not critical to the outcorne of the accident with surface-to-volume ratio correction.
L. sed on the progression. With both containment sprays and ECCS structural response issues expert opinion elicitation used operating in the injection mode, the RWST (Refueling for the NUREG 1150 study, the containment failure Water Storage Tank) was depleted at the 50 minute mark, pressure was specified at 0.97 MPa (9.7 bars,140.7 according to the. MELCOR simulation, with the psia)..The STCP calculations defmed containment failure g
g pressure at 0.93 MPa (9.3 bars, 135 psia).
The g
f g
MELCOR calculations were run on an IBM RISC-6000 ECCS systems. The MELCOR simulation continued in Model 550 workstation, with the AG sequence requiring this mode, with sprays and ECCS systems in operation, 128,000 seconds of computing time to run through up until the 960 nun point, when the operators shifted 300,000 seconds of accident time; the S2D sequence used ECCS injection from the loop cold legs to the hot legs, as 27,400 seconds to carry tne simulation through 50 000 per emergency procedures. With the containment spray -
~1 seconds, and the S3D sequence required 93,000 computer g
g
,, g
- seconds to simulate 100,000 seconds.
gg g;
in a linear fashion. STCP predicted containment failure 5.2 AG Sequence at 3,054.2 min, based on a containment failure pressure of 9.3 bars (~ 135 psia), while MELCOR predicted the The AG accident sequence analyud with MELCOR was containment to fail at 3,540 min, using 0.97 MPa (9.7 l
charactenzed by a 0.74 m (29 in) diameter break m the bars,140.7 psia) as the failure pressure. Both codes l
Loop A hot leg combined with loss of containment heat assumed ECCS failure' within about a minute of.
removal capability, but with all the other safety systems containment failure. ' At that point, there was no further operational The main features and assamptions of this source of water to the primary system, and it entered a sequences are briefly described in Section 3.1-boiloff stage.
5,2.1 Key Events STCP predicted the start of core uncovery at 3,080.6 min, and MELCOR predicted this to occur at 3,570.2 min.
Table 5.2.1 summarizes the AG accident sequence MELCOR modeled ths core in 3 radial rings and 10 axial predicted timing of events for both the STCP and nodes. MELCOR predicted the onset of zircaloy cladding MELCOR calculations, starting with accident initiation, oxidation at 3,619.6 min, with the initial gap release
!)
~
Immediately upon rupture of the 0.74 m (29 in) diameter occurring at 3,621.5 min, both m ring I.. MELCOR Loop A hot leg pipe, the primary system commenced a predicted the start of core melting in the innermost ring at-rapid blowdown, pressurizing the containment above the 3,665.0 min. STCP did not differentiate between the j
25 psia containment spray initiation setpoint injust a few different core components and predicted core melt.to seconds.
Both STCP and MELCOR predicted begin at 3,155.6 min. MELCOR calculated the beginning
. containment sprays to begin delivery in less than a minute of core collapse in radial ring I at 3 684.3 min, while after accident initiation. With the massive blowdown, the STCP calculated global core collapse at 3,209.2 min; contamment sumps fill rapidly to a level sufficient to Since the MELCOR analysis produces a more gradual allow the containment recirculation sprays to begin collapse of the core than STCP, the reactor vessel bottom delivery within a few minutes, adding their flow to that head did not completely dry out prior to failure. For the already present due to the injection sprays.
STCP run, bottom _ head dryout was predicted at 3,237.6 min, and bottom head failure at 3,371.6 min. MELCOR While the containment safety systems were delivering calculated failure of the bottom head in the region -
water through the spray systems, the active and passive underneath radial ring 1 at 3,685.4 min. For both the emergency core cooling systems were supplying water to MELCOR and STCP rtms, debris ejection began the primary, A rather large difference exists between immediately, with the entire mass of molten corium STCP and MELCOR concerning the time when the transferred to the cavity in a single time step for the passive accumulators were fully discharged.
STCP STCP rtm. The MELCOR calculation took on the order 13 NUREG/CR-6107
=.
Resuhs and Comparisons
'of 45 min to transfer the core from the vessel to the temperature of the gas exiting the core rose to nearly 850 cavity. For both codes, as soon as molten corium was K (1,0707) at the time of vessel failure, transferred to the cavity, core concrete attack began, producing aerosols and gases in the process Neither code predicted deflagrations, as the containment was Figure 5.2.4 is a plo: of collapsed and swollen liquid steam inerted at this point.
levels in the reactor vessel, in the upper plenum, core and lower plenum. (Dotted lines are provided in the figure 5.2.2 Primary System Behavior indicating the top-of-core / bottom-of-UP clevation at 6.72197 m and the bottom-of core / top-of-LP elevation at 3.06437 m, for reference.) There was very little level Figures 5.2.1 through 5.2.4 show primary system response based on parameters calculated by MELCOR.
swell predicted anywhere in the vessel except in the core.
Figure 5.2.1 shows the pressure response of the upper The core remained fully covered until the 960 min point plenum (CV140), the vessel downcomer region (CV100),
in the accident, when the ECCS flow is shifted from cold and the core (CV120), all virtually identical. Due to the legs t hot legs. At that point, the water level in both the large size of the break in hot leg A, the primary pressure d wnc mer and the core fell below the top of the active fell very rapidly at the start of the accident, reaching fuel, even though significant liquid still remained in the equilibrium with containment at about the I minute mark.
upper plenum. The collapsed liquid level in the core From that point onward, the primary system pressure dropped to about the core midplane, but the significant tracked containn ent pressure (presented later in Figure level swell in the core kept the swollen leve'. near the top 5.2.7) as it slowly increased to the failure pressure of f the active fuel, and thus maintained core cooling.
0.97 MPa (9.7 bars,140.7 psia). With containment Water levels then remained about constant until failure at 3,540 minutes, the primary pressure fell to c ntainment failure at 3,540 min, when ECCS flow was atmospheric.
lost. At that point, the water levels in the vessel dropped quickly, with all inventory lost at the point of vessel Primary temperatures in the reactor vessel downcomer I wer head failure,3,685.4 min.
end upper plenum control volumes are given in Figure 5.2.2.
As long as the ECCS systems injected into the Integrated outflows from the primary system through the cold legs, the reactor vessel downcomer volume was a hot leg break and through the vessel breach are given in few degrees cooler than the upper plenum volume.. At Figures 5.2.5 and 5.2.6, respectively; the outflows are 960 min, when ECCS flow was shifted from cold legs to subdivided into liquid water, steam and hydrogen flows in hot legs, the temperatures in the downcomer and lower both cases.
As expected in a large break LOCA plenum volumes became essentially the same.
This sequence, most of the RCS inventory is lost as liquid remained the case until containment failure at 3,540 min, water out the break. Liquid remaining in the lower when all ECCS flow was lost to the primary system and plenum at the time of vessel lower head failure is lost out boiloff of the remaining coolant inventory began. At that the vessel breach to the cavity, point, the temperature of the upper plenum spiked upward, reflecting the effect of the core uncovery and 5.2.3 Core Degradation melting.
Figure 5.2.7 through 5.2.9 show cladding temperatures Figure 5.2.3 shows the core exit gas temperature as predicted at different axial levels in the various radial predicted in the upper plenum control volume (CV140),
rings during the core damage period.
(Recall that and also the local core fluid temperatures in the MELCOR modelled the core in 3 radial rings and 10 axial uppermost axial level in each radial ring. Steam exited levels in the active fuel region.) The behavior in all three the core at about 400 K (2607) for the first 960 min. At rings is very similar, only slightly delayed in time in the that juncture, the temperature of the exi'ing gas jumped outer rings due to lower power densities. MELCOR because the ECCS flow had been redirected from the loop predicted the start of core heatup in the uppermost axial cold legs to the hot legs. After settling down to about levels immediately after core uncovery began. Core 425 K (3057) by 1,600 min, the temperature increased uncovery and core heatup continued with no major clowly to around 450 K (3507) by the time of interruption, with cladding oxidation and initial gap i
containment failure, a reflection of the gradual heatup of release beginning at ~3,620 min. ' The core heatup and the coolant inventory being recycled through the core by damage was quite rapid - MELCOR predicted the start the ECCS systems. With ECCS no longer available, the of core melting in the innermost ring at 3,665 min and NUREG/CR-6107 g4 i
Results and Comparisons core collapse and lower head penetration failure about 20 containment to fail slightly earlier in the STCP calculation min later.
than in the MELCOR calculation. With containment failure at 3,054.2 min for the STCP calculation and at Figure 5.2.10 shows the total masses of core materials 3,540.0 min for the MELCOR calculation, the pressu e (UO, Zircaloy and zirc c,xide, stainless steel and steel and temperature within containment fell rapidly. The 2
oxide, and control rod poison) remaining in the vessel pressure returned to ambient, while the containment during the later portion of the AG transient. Figure atmosphere temperature stabilized at around 373 K 5.2.11 shows the same information, but normalized by the (212*F), saturation temperature at ambient atmospheric initial masses of each material present. (Note that the pressure.
fractions of ZrO and steel oxide use the initial masses of 2
zircaloy and stainless steel, respectively, as normalizing Figure 5.2.16 shows the mole fractions of steam, masses, because no oxides are present initially.) Debris nitrogen, oxygen, hydrogen and other noncondensable ejection began immediately after lower head failure, and gases in the cavity control volume (CV010). The results it took on the order of 45 min to transfer the majority of for the cavity control volume atmosphere given in figure the core material from the vessel to the cavity. All the is representative of the other containment control UO is transferred to the cavity, as is most of the volumes, and it shows that prior to failure the containment 2
unoxidized zircaloy and almost all the oxides; however, is steam inerted. After containment failure, practically all much of the steel in the core support plate and the lower of the noncondensible gases are swept out-into the plenum structure is predicted to remain unmelted and in environment leaving only steam in the containment place even after vessel breach.
atmosphere.
No combustible gas deflagrations are predicted, by either the MELCOR or STCP codes.
The temperature and mass of debris in the lower plenum (i.e., on the lower head) are presented in Figures 5.2.12 Figure 5.2.17 shows the total decay heat present during and 5.2.13. There is only a brief period of time when a the accident, along with the amount associated with the substantial mass of debris is found in the lower plenum, cavity after reactor vessel bottom head failure. Itis-between initial core plate failure and initial lower head apparent that most of the fission products are retained in penetration failure and ejection to the cavity, the cavity, either in the corium or in the cavity water.
This is due, in part, to the reactivation of the containment 5.2.4 Containment Response sprays after containment failure.
in the MELCOR calculation being reported here, these Containment pressure and temperature response are presented in Figure 5.2.14 and Figure 5.2.15 as sprays were lost at the ~65,000 see (1,083 min) mark, calculated by MELCOR and with the corresponding STCP due to a control function that checks to see if the sump result [Ref.1, Vol.3, Figures 4.1 and 4.2] given for water used as the source ofinventory for the containment comparison. The containment atmosphere pressures and sprays in recirculation mode is too hot to allow the system temperatures predicted by both codes behaved in similar t pump it (a way of looking at NPSH difficulties). If ways. The pressures and temperatures rose precipitously that is the case, the sprays fail. What happened in the run in the initial minutes of the accident, in reaction to the is that the sprays failed for this reason, and then, with the rapid initial blowdown of primary system coolant, and containment failure and depressurization of the then decayed back down to the 0.1 MPa (1 bar,15 psia) containment back to ambient atmospheric conditions, the end 330 K (135*F) range, as relatively cold water was sprays reactivated themselves (not a likely thing to injected to the containment volumes by the containment happen) and began spraying water again, just when the spray injection system and to the primary system via the inventory of aerosols in the containment atmosphere was nchest.
ECCS injection systems. After the RWST was depleted of cool water, the conteinment began its slow heatup and repressurization, as energy was released to a containment Since the thrust of our work was to estimate'the source without capability for heat removal.
During this term to the containment, it may be immaterial whether the pressurization period, the containment temperature radionuclides have been washed out of the atmosphere by remained at the corresponding saturation temperature.
the sprays or are located somewhere else.
If the The containment pressurized slightly faster in the STCP inventory split between pools, deposition onto heatsinks, analysis which combined with the different failure and suspension in the containment atmosphere is deemed pressures assumed in the two analyses caused the critical to the presentation of this report, then the AG 15 NUREG/CR-6107
1 Results and Comparisons sequence needs to be rerun with containment spray controi 5.2.5 Fission Product Transport and
- parameters adjusted to make the sprays behave in Release to the Environment 1
whatever manner is deemed most suitable.
-l The overall behavior of fission products released from The mass of core debn..s m the cavity, the mass of ablated fuel is described in Tables 5.2.2 and 5.2.3 and shown concrete, the mass of gas produced, and the total mass of gnphically in Figures 5.2.24 through 5.2.47. Tables debns (including core debns together with ablated and
'3 8 ** *
- l '"
""'1id*
f* ', "*! '
d.' 9 " ion at the end of the accident simulat,on,3,973.
reacted concrete) are presented in Figure 5.2.18. Before istnbut i
about 4,133 min, the debn.s m the cavity was primanly min for STCP and 5,000 min for MELCOR. Figures debns ejected from the vessel; after that time sigmficant 5.2;24 through 5.2.35 show the mass of radionuclides, by.
core-concrete mteraction began and substantial masses of 6spu eMAre WhMM ablated and reacted concrete were added to the total cavity both the.m-vessel and ex; vessel portions of the accident, along with a trace givmg the sum of the two, all by the initial inventories of each class.-
u nna Figure 5.2.19 shows the mass inventories of the metallie Figures 5.2.36 through 5.2.47 are plots of radismuelide and' oxidic debris in the cavity, and Figure 5.2.20 shows masses released into the primary control volumes, the the temperature histories of those debris layers. At around c ntammem mmmt v lumes, e en nment, and a sum 4,133 min, a CORCON layer flip occurred, in which the total of the three, also normalized by the imtsal mventory debris bed switched from en initial configuration with a P*##
- '*"N"'**
' * ""Y metallic debris layer above a heavy oxide layer to a later mu es mpe e atm sphere and deposited.
configuration with a light oxide layer above a metallic
[am pools and n structures, but do. not include debris layer. This layer flip occurred.when enough radionuclides stili in the fuel debns in the core and/or concrete had been ablated (with its resultant low-density silicate oxides) to dilute the high-density zirc oxide and steel oxide debris to an average density value less than the Fuel damage does not occur until after failure of the metallic debns density.
ECCS systems; and by e.at point, the containment has 1;
failed already. Thus, a path to the environment was Figure 5.2.21 shows cavity heat sources due to decay heat P*" * ""
8'E '" '"*8 and chemical reactions occurring in the corium. It is
~3,620 min. Prior to reactor vessellower head failure, interesting to note that, for a brief period around the np cts were trany m
may system 4,133 min mark, the chemical reactmn energy release is and into the containment via the Loop A 0.74 m (29 in) roughly 7 times the magnitude of the energy release due diameter hot leg break.
At lower head penetration to decay heat. This time corresponds to the CORCON failure, m Iten c rium was transferred m. stages to the.
layer Hipjust described.
cavity, where further fission product release to the The CORCON layer inversion resulted in greatly increased heat transfer from the melt to the concrete. The g
gg g
maximum cavity depth and radius are presented in Figure MELCOR and STCP simulations, significant differences 5.2.22. The relocation of the metallic layer to the bottom et st. As noted above, besides the fact that MELCOR of the cavity causes an increase in the rate of ablation models revola'ization of radionuclides from the primary vertically downward and halts further radial ablation. The g gp ggg gg heat generated by chemical reactions withm the cavity 6
hMhhd also m, ereases dramatically at this point, as just noted m gg g g gp g
M gum x.22.
the MELCOR simulation, they were in operation at this I ***
Figure 5.2.23 gives an accounting of the total mass of non-condensible gases released from the cavity and from The fractional release of radionuclides into the the core during core darnage and during core-concrete g
gg g
mteraction.
The majority of non-condensible gas g
g gg produced is carbon monoxide, and the majority of that identified by the representative elements Xe, and Cs.
production occu s in the cavity during core-concrete MELCOR: predicts a significantly higher fractional distribution for Ba and marginally : higher for I.
NUREO/CR4107 16
' l
Results and comparicte MELCOR predicts a higher release for Ru, too; but only predicted to occur in the cavity, similar to the behavior of trace amounts are being compared. Both codes predict Class 3 (Ba) and Class 5 (Teb All of the Class 8 (Ru) the bulk of the Ru to remain in the core debris in the and almost all of the Class 11 (Cd) releases are predicted cavity. Comparisons between the two codes for fractional to occur in-vessel, Class 7 (Mo), Class 8 (Ce), Class 10 distribution of Ce and La show some differences between (U) and Class 12 (Sn) have most of their releases
-l trace amounts in the containment and environment, predicted to occur in-vessel, but a significant, non-zero, combined, but both codes show nearly all of the inventory fraction of the initialinventory of these classes is released of these radionuclides residing in the fuel debris in the in the cavity.
cavity. - MELCOR predicted the fractional distribution of Te for the combined containment and envimament to be The released radionuelide distributions are also predicted significantly less than was predicted by STCP; the to fall into a few subdivisions. All of the noblejases fractional distribution in the RCS was smaller for the (Class 1) and iodine (Class 4) are releasul to the MELCOR run, a significantly larger fraction resided in environment by the end of the MELCOR simulation, the cavity, the containment inventory was roughly equal Most of the Ba, Te and La (290% of the rmount to the.STCP value, but the fraction released to the released) remain in the containment, with ~5% of the environmeu was much less than for the STCP run.
amount released still in the RCS and ~5 % h,st to the environment. All of the other classes have ~75% of the -
Figures 5 2.24 and 5.2.25 show that almost all of the amount released remaimng in the containment, with Class 1 and Class 2 volatiles are released imm the fuel m
~ 15 % of the amount released stillin the RCS and -10%
the MELCOR calculation. About 60% of that release lost to the environment.
occurs in-vessel, with the renuining ~10% released ex-vessel in the cavity. Note that Figure 5.2.27 shows a very The total mass of fission products released from the fuel similar release pattem for Class 4 (halogens like iodine, is shown in Figure 5.2.48. More than half the total also considered volatiles) in-vessel, but no additional re'. se occurs during in vessel core damage and melt release in the cavity. This is due to a coding problem in ejection. The in<avity release primarily occurs before the' McLCOR: the VANESA code, which is used to calculate CORCON layer flip at around 4,133 min, with very httle the ex-vessel release within MELCOR, considers iodine release at later times. Most of the fission products i-to be released as Csit since there is no separate Csl class released are found in control volumes, -in either in these MELCOR ealculations, MCLCOR counts that Csl atmosphere or pool, and about 50-70% of the fission release to be a Class 2 (Cssi release (ineidentally products in the control volumes are vapors rather than explaining why the total Class 2 release fraction shown in aerosols (mostly because aerosols settle out and deposit Figure 5.2.25 is greater than 100%, which should be onto beat structures more readily). Very few (s5 %) of impossible). Based upon physical insight, the Class 4 the fission products are oeposited onto heat structures.
release should closely r-semble the Class I and 2 results.
The release behavior predicted by MELCOR can be 5.3 S2D Sequence grouped into Several subdivisions. Assuming the correct iodine behavior, ~ 100% of the Class 1, Class 2 and This accident sequence was initiated by a 0.05 m (2 in)
. (corrected) Class 4 radionuclide inventories are released, diameter break in the Loop A bot leg. The main features about 50%/50% in-vessel and ex. vessel. The next major and assumptions controlling this sequence are described release fractions are of Ba/Sr (~ 15 %) and Te ( ~ 25 %),
briefly in Section 3.2.
both mostly predicted to occur in the cavity. About 6-7 %
~
of the Cd and Sn radionuc:ide inventory is released, and 5.3.1 Key Events about 3% of the Mo radionuclide inventory. (Note that these amounts consider only the release of radioactive Table 5.3.1 provides a summary of the event timing for forms of these classes, and not additional releases of the S2D accident sequence from both the STCP and nonradioactive aerosols from structural materials.)
MELCOR calculations. He starting point is accident Fmally, a total s0.02% of the amtial inventory of the initiation, when a 0.05 m (2 in) diameter Loop A hot leg refractories (Ru, Ce, La and U) are released.
pipe break occurred, and blowdown of the primary system coolant inventory to the containment began, By 1.0 min The release patterns become more varied as the relene in the STCP calculation and 0.3 min in the MELCOR amount decreases. Mort of the Class 9 (La) releases are calculation, the containment fan coolers shifted from 17 NUREG/CR-6107
Results and Comparisons normal operation to high capacity operation, when the predicted core slump at _176.8 min. STCP indicated containment atmosphere temperature rose above 313.7 K global core collapse at 180.6 min, while MELCOR r
(105 *F). According to the accident sequence definition, predicted collapse of the inner core segment, as modeled the operators took action to depressurize the secondary by rarlial ring 1, at 146.7 min.
side of the swam generators, beginning at 30 min and scheduled for completion at 60 min. Initial core uncovery With the melting and collapse of the core, containment occurred in the STCP calculation at 41.3 min and at 35.6 pressure rose to the initiation setpoint for the containment min for MELCOR.
For both calculations, initial sprays, 0.17 MPa (1.7 bars, 25 psia). Two things accumulator delivery commenced after the core had begun happened at that point. The containment coolers tripped to uncover, at 44.0 min for the STCP calculation and off, and the containment spray injection systeni, drawing 38.8 mm for the MELCOR calculation. STCP pralicted water from the Refueling Water Storage Tank (RWST),
an uninterrupted delivery of accumulator water to the began operation. STCP predicted the containment sprays primary system that continued until depletion at 65.0 min.
to commence injection at 188.0 min, while MELCOR MELCOR predicted delivery in two stages, with the first predicted this to occur at 267.0 min. In conjunction with finishing at 68.6 min, after having delivered 85 percent of the Injection Spray System, the Recirculation Spray the total accumulator inventory. MELCOR predicted a System c immenced operation at 282.4 min for the STCP second accumulator delivery of the remaining inventory simulation and at 272 min for the MELCOR run. Water between 158.0 min and 158.5 min, after the core had circulation through the Recirculation Spray System coolers begun to collapse.
Both codes predicted initial provided heat removal capability for the containment.
accumulator delivery beginningjust after the start of core While STCP predicted bottom head dryout to occur at uncovery, such that the core was recovered, but then a 2.09.2 min, prior to bottom head failure at 314.4 min, the second core uncovery occurred. Timing for the second MELCOR run predicted a much earlier localized bottom uncovery was 114.7 min according to STCP and 101.9 head failure in ring I at 148.3 min, with water still min for MELCOR. The MELCOR core model consisted remaining in the lower head at that time. Debris ejection of 3 radial rings and 10 axial nodes. Because of the to the cavity began immediately upon lower head failure recovering of the core with accumulator water, MELCOR for the STCP run, with the onset of concrete' attack at predicted gap release in radial rings 1 and 2 prior to the 315.5 min. For the MELCOR run, debris ejection to the onset of zircalo) oxidation. Radial ring i gap release was cavity was delayed until 164.4 min, some 16 min after predicted at 46.5 min, ring 2 gap release at 48.1 min, and bottom head failure, due to the more gradual collapse of cladding oxidation at 61.7 min. MELCOR predicted gap the core and the cooling effect of the water resident in the release for radial ring 3 much later, at 135.7 min, due to lower head. MELCOR predicted the onset of concrete the cooling effect of the accumulator water addition to the attack and a layer inversion in the cavity at 333.3 min.
primary system.
STCP predicted corium layer inversion at 372.5 rr.in.
i A large difference in timing is evident between the two 5.3.2 Primary System Behavior codes for their predictions of when the operators depressurize the primary system via the power operated Conipared to the rapid blowdown exhibited during the AG relief valve, (PORV).
For both simulations, sequence large break LOCA, the primary behavior for the depressurization of the primary system was scheduled to S2D sequence was much more benign in nature, commence when the core exit gas temperature reached However, with no Emergency Core Cooling Systems 922 K (1,200*F). This occurred for the MELCOR run at (ECCS) injecting makeup water to the primary system, 49.0 min and at 148.0 min for STCP. The difference is the accident progressed with greater rapidity than did the not likely to have affected the final source term release to AG sequence. Figures 5.3.1 through 5.3.4 give primary the containment very much. The nodalization of the core system response based on the MELCOR calculation.
in the MELCOR ruc, such that the core melts in discrete stages, is the likely reason for the large timing difference Figure 5.3.1 shows the primary system pressure during between the runs.
the accident progression for the MELCOR analysis.
After accident initiation, the primary pressure fell quite MELCOR predicted the onset of core melting in the rapidly during the first few minutes from normal system inside radial ring at 130.0 min, as compared to the STCP pressure to 6 MPa (60 bar, 870 psia) and then made a value of 161.6 min. Core slump in the MELCOR run rapid reversal, climbing back up to 7.4 MPa (74 bar, occurred at 140.0 min, again in radial ring 1, while STCP 1,075 psia) by the 15 min mark. At that point, the NUREG/CR-6107 ig
Resuhs and Comparisons primary pressure stabilized as decreasing primary accumulator water to the core and the resulting rapid inventory was offset by increasingly hot steam exiting the production of steam. His temperature spike is quite reactor core upper plenum. At 30 minutes, the first of apparent in Figure 5.3.3, the plot of core exit gas several events occurred that reversed the primary temperature, rising to near 1,040 K (1,4127) prior to repressurization trend, causing a precipitous drop. The falling back to the 600 K (6207) range at the end of the first event was the operator initiated depressurization of initial delivery of accumulator water at 69 min. With the the steam generator secondaries, beginning at 30 minutes start of the second core uncovery at 102 min, the upper and concluding at 68.6 minutes. Secondly, as the primary plenum temperature began to oscillate between 475 K pressure fell below the passive accumulator setpoint,4.24 (3957) and 625 K (6657), while the downcomer MPa (42.4 bars, 615 psia), they began delivery of water temperature remained about 475 K (3957). As the core to the cold legs.
MELCOR predicted initial core began to melt at 130 min and progressed into core slump uncovery at 35.6 minutes, with accu rmlator discharge at 140 min, the primary temperatures began a steady beginning at 38.8 minutes. Hirdly, MELCOR predicted climb to approximately 1,100 K (1,5207) by the time of that the core exit gas temperature reached 922 K core collapse. Quenching of the molten corium in the (1,2007) at 49 minutes, prompting the operators to lower head served to lower the primary temperature depressurize the primary system by opening the PORV somewhat just prior to vessel failure and subsequent valve.
By approximately the 70 minute mark, the debris ejection at 164 min.
MELCOR analysis showed the primary pressure reduced to the IMPa (10 bar,145 psia) level, where it remained Figure 5.3.4 provides a plot of collapsed and swollen until bottom head failure in ring I at 148.3 minutes. At water levels in the reactor vessel, in the upper plenum, that point, the primary pressure equalized with core nnd lower plenum. (Dotted lines are provided in the containment pressure.
figure indicating the top-of-core / bottom-of-UP elevation at 6.72197 m arid the bottom-of< ore / top-of-LP elevation The primary system pressure predicted by STCP [Ref.1, at 3.06437 m, for reference.) Since the only source of Vol. 6, Figure 4.2.50] is included in Figure 5.3.1 for water to the piimary is the accumulators, the collapsed comparison to the MELCOR calculation. The results are levels track their performance. Reactor vessel water qualitatively very similar for the first - 150 min, with the inventory fell from the outset, with initial core uncovery MELCOR RCS pressure predicted generally slightly at 35.6 min. The coolant level continued to decrease until lower than the STCP predicted response.
De the accumulators began delivery at 38.8 min and repressurization at 180-220 min in the STCP result has no continued to rise until they ceased delivery at 68.6 min, counterpart in the MELCOR analysis; it corresponds in having successfully recovered the core. From that point timing to the period between core ecliapse (at 180.6 min onward, the coolant inventory decreased, and the for STCP) and bottom head dryout (at 209.2 min for collapsed water level in the reactor vessel fell in a linear l
STCP), and is likely due to boiling off the remaining fashios. The core uncovered for the second time at 101.9 j
lower plenum water inventory. MELCOR fails the lower min and was almost completely voided at the time of head very soon after core collapse (148.3 min and 146.7 vessel failure,148.3 min. As seen for the AG sequence min, respectively), and thus any water left in the lower in Figure 5.2.4, there was very little level swell predicted plenum simply falls into the cavity; after lower head anywhere in the vessel except in the core. The core failure, the MELCOR RCS pressure calculated remains coll... sed and swollen liquid levels both fell even during essentially at the containment pressure.
those periods when significant liquid still remained in the upper plenum. The significant level swell in the core.
1 Figure 5.3,2 gives primary temperatures in the reactor during these periods helped maintain core cooling.
vessel downcomer and upper plenum cc-21 volumes.
One must keep in mind that after the onset of debris Integrated outflows from the primary system through the ejection at 164.4 min, the downcomer and upper plenum hot leg break and through the vessel breach are given in had been drained of water, for all practical purposes. The Figures 5.3.5 and 5.3.6, respectively; the outflows are j
primary temperatures in the downcomer and upper subdivided into liquid water, steam and hydrogen flows in plenum were in the 550 K (5307) range until the start of both cases. Mast of the RCS inventory is lost as liquid operator initiated depressurization of the steam generator water out ste break. Liquid remaining in the lower secondaries, when they began a downward trend. An plenum at tie time of vessel lower head failure is lost out abrupt temperature spike in the upper plenum temperature the vessel breach to the cavity. Note that relatively less occurred at 39 min, coincides with the delivery of inventory is lost out the small break and relatively more 19 NUREG/CR-6107
t I
Results and Comparisons oct the vessel breach than predicted for the large break 5.3.4 Containment Response LOCA in the AG sequence (Figures 5.2.5 and 5.2.6).
P The containment pres ure and temperature response, for (5.3.3 Core Degradation both the MELCOR and the STCP calculations, are presented in Figure 5.3.14 and Figure 5.3.15.
(The This core panial uncovery, recovery and final uncovery STCP results are taken from Ref.1, Vol. 6, Figures' is also visible in the core temperature response predicteJ.
4.2.55 and 4.2.56.) Qualitatively, the predictions made l
Figures 5.3.7 through 5.3.9 show cladding temperatures by both codes concerning containment pressure and at various levels in the different radial rings during the temperature were similar, although the timing of the core damage period. The behavior in all three rings is events varied between the two codes. Pressure and
~
very similar, only slightly delayed in time in the outer two temperature spikes attnomable to hydrogen deflagrations -
rings due to lower power densities. MELCOR predicted for the MELCOR run are the major difference between core heatup in the uppermost axial levels beginning at the two. The STCP analysis did not allow hydrogen about 35 min, when the core first uncovers. By about 50 burns to occur.
min, the upper half of the core showed elevated clad temperatures. Accumulator injection interrupted core Both cales predicted a relatively rapid nse in containment uncovery and heatup, with almost all of the core pressure after accident initiation as blowdown fmm the recovered to saturation temperatures by 70 min. After prinury system entered the containment via the break.
I that time, wah the loss of the accumulator water injection, With depressurization of the steam generator secondanes the core began to heat up again and damage was quite commencing at 30 min, the containment pressurizatior rapid - MELCOR predicted the stan of core meltmg in curve hyan to turn over, almost reaching the 0.172 MPa the innermost ring at 140 min and core co!Iapse and lower (1.72 bar, 25 psia) contr.irment spray initiation setpoint in head penetration failure about 10 mm later.
the STCP calculation prior to falling off at the 65 min ma rk. MELCOR predicted the containment pressure to.
i Figure 5,3.10 shows the total masses of core materials rise to 0.134 MPa (1.34 bar,19.4 psia) at 39 min, when (UO,, Zircaloy and zirc oxide, steel and steel oxide, and the effects of steam generator secondary depressurization control rod pois(m) remaining in the vessel during the and accumulator delivery to the pnmary helped reduce
-l S2D trans' ent.
Figure 5.3.11 shows the same containment pressure to approximately 0.126 MPa (1.26 I
i information, but nonnalized by the initial masses of each bar, 18.3 psia) by 68.6 min, when both initial j
material present. (Note that the fractions of ZrO and accumulator water delivery and secondary side I
2 steel oxide use the initial masses of z.ircaloy and stainless depressurization were completed.
i steel, respectively, as normalizing masses, because no oxides are present initially.) Debris ejection began about The STCP calculation predicted a repressurization of the 15 min after lower head failure. As in the AG-sequence containment up to the containment spray initiation setpoint l
results shown in Figures 5.2.10 and 5.2.11, all the UO of 0.172 MPa (1.72 bar,25 psia) at 188 min,- followed by 2
is transferred to the cavity, as is tnost of the unexidized a steep decline in containment pressure as the containment zircaloy and the oxidas; however, much of the structural sprays injected relatively cool water from the RWST until:
)
steel in the lower plenum and core support plate is it was depleted at 282 min.
At that pointc with j
predicted to remain unmelted and in place even after containment pressure at approximately 0.09 MPa (0.9 bar, vessel breach.
13 psia), the containment recirculation sprays began !
operation. Their coolers were operable, but were unable The ternperature and mass of debris in the lower plenum to fully counteract the increase in containment pressure (i.e., on the lower head) are presented in Figures 5.3.12 that occurred as the core melted, rupturing the reactor i
and 5.3.13. There is only a brief period of time when a vessel lower head, and fell into the cavity at 315 min. By substantial mass of debris is found in the lower plenum, definition, the STCP analysis did not allow the culten between initial core plate failure and initial lower head corium in the cavity to be quenched. By the end of the-l penetration failure and ejection to the cavity. Again, this run at 915.5 min, the containment pressure had risen.
I is quite similar to the corresponding results for the AG gradually after corium layer inversion had been completed sequence given in Figures 5.2.12 and 5.3.13, except in at 372.5 min, to 0.14 MPa (1.4 bar, 20.3 psia), well -
timing.
below containment failure pressure.
-. ~,
Results and Comparisons The MELCOR analysis predicted a similar type of through 5.3.23 provide information concerning decay behavior, with the added spice of hydrogen deflagrations heat, both total and the portion connected with the cavity, thrown in for good measure. After the end of accumulator along with characteristics of the debris resident in the delivery to the primary, the containment pressure rose to cavity after lower head failure. By the end of the approximately 0.14 MPa (1.4 bar, 20.3 psia) by the time MELCOR analysis, the corium debris temperature was of debris ejection,164.4 min. Along with debris ejection, approximately 1,650 K (2,510"F) and trending downward a hydrogen deflagration in the cavity caused a small slowly.
containment pressure spike up to 0.16 MPa (1.6 bar,23.2 psia). After decaying, the containment pressure began to 5.3.5 Fission Product Transport and Release rise again, as the corium in the cavity reacted with the to the Environment concrete, adding noncondensible gases to the containment atmosphere. Contair nent pressure rose to the 0.172 MPa The STCP analysis did not look at source term releases (1.72 bar, 25 psia) level at 267 min in the MELCOR for the S2D accident. The following discussion therefore calculation, and the resulting containment spray injection refers solely to MELCOR source term results. (Recall flow helped to lower containment pressure back down t that, for reference, Table 4.2.1 gives the list of the the 0.09 MPa (0.9 bar,13 psia) level by 300 min, much MELCOR fission product classes and their total the same as had happened with the STCP run. From that radioactive mass inventories.) Table 5.3.2 gives the point, the MELCOR analysis predicted two distinct sets radionuclide fractional distribution at the end of the of hydrogen deflagrations involving numerous containment MELCOR analysis, 833.4 min. Figures 5.3.25 through and primary system volumes, at the 310 min and 332 min 5.3.36 show the radionuclide mass fraction, according to marks. The first raised containment pressure by just a fission product class, released from the fuel in the in-few bar, and the second caused a more pronounced spike vessel and ex-vessel portions of the accident, accompanied up to 0.24 MPa (2.4 bar, 34.8 psia), the maximum by a trace showing the total of the two. Figures 5.3.37 containment pressure witnessed during the MELCOR through 5.3.48 give plots of radionuclide masses in the analysis.
A third series of hydrogen deflagrations primary, containment, environment, and a sum total of all occurred between 385 min and 470 min, raising three, all as a fraction of the initial class inventory containment pressure to about 0.125 MPa (1.25 bar,18.1 present. Since the containment was not predicted to fail, psia) by the 470 min mark. At the end of the MELCOR no releases to the environment occurreci.
simulation,833.4 min, the containment pressure had risen slightly, to 0.14 MPa (1.40 bar, 20.3 psia), exactly the Signific.mt radionuclide releases from the fuel occurred at same as predicted by the STCP analysis.
the outset of core melt, - 130 min, and continued through the remainder of the in. vessel portion of the accident and Little needs to be said concerning the containment on into the ex-vessel segment. Transportation to the atmosphere temperature plot, Figure 5.3.15, except to say containment for the more volatile radionuclide classes was that once the containment atmosphere became saturated rapid, while the less volatile classes showed significant early in the accident analysis, it remained saturated, and release from the fuel after it had relocated to the cavity.
the containment atmosphere temperature reflected that Generally, for the noble Fases, halogens, and main group condition. The STCP plot of containment atmosphere metals, releases to the containment were finished by 250 temperature is a more benign trace since it does not min.
The other radionuclide groups were slower, reflect the spikes caused by hydrogen deflagrations that completing their releases from the fuel mass to the are present in the MELCOR plot, containment by approximately 330 min. After the point, very little release of radioactive radionudides to Figures 5.3.16 and 5.3.17 show the mole fractions of containment occurred.
steam and noncondensables in the cavity and containtnent dome control volumes, respectively.
Since the As discussed in Section 5.2.5 for the AG sequence containment was not steam inerted at the time of lower results, Figures 5.3.25 and 5.3.26 show that almost all of head failure and debris ejection, hydrogen deflagrations the Class 1 and Class 2 volatiles are released from the occurred in containment for the MELCOR analysis, fuel in the MELCOR calculation. About 50% of that initially in the cavity volume. Later deflagrations were release occurs in-vessel, with the remaining 50% released distributed throughout the containment volumes. None ex-vessel in the cavity. Note that Figure 5.3.28 shows a threatened containment integrity. The STCP analysis did very similar release pattern for Class 4 (I) in-vessel, but not consider hydrogen deflagrations. Figures 5.3.18 no additional release in the cavity. This is because 1
4 21 NUREG/CR-6107 i
Results and Comparisons VANESA, which is used to calculatc the ex-vessel release volumes are vapors rather than aerosols (mostly because withm MELCOR, considers iodine to be released as Cst; aerosols settle out and deposit onto heat structures more since there is no separate Csl class in these MELCOR readily). Relatively few fission products (s5%) are calculations, MELCOR counts that Csl release to be a deposited onto heat structures in this sequence.
Class 2 (Cs) release (also explaining why the total Class 2 release fraction shown in Figure 5.3.26 is greater than
]
100%). Based upon physical insight, the Class 4 release 5.4 S3D Sequence should closely resemble the Class 1 and 2 results.
This accident sequence was initiated by a very small
)
He release behavior predicted by MELCOR can be break, characterized as a pump seal LOCA, with a total grouped into several subdivisions. Assuming the correct leak rate at normal operating conditions of 2,839 liters per iodine behavior, ~ 100% of the Class 1, Class 2 and min (750 gpm). All other pertinent accident sequence (corrected) Class 4 radionuclide inventories are released, characteristics were identical to those specified for the about 50%/50% in-vessel and ex-vessel. The next major S2D sequence described in Section 3.2.
release fractions are of Ba and Te (~ 30%), both mostly predicted to occur in the cavity. About 12-14% of the Cd 5.4.1 Key Events and Sn radionuclide inventory is released, and s3% of the Mo radionuclide inventory. (Note that these amounts The summary of event timing for the S3D accident consider only the release of radioactive forms of these sequence is provided in Table 5.4.1, for both the STCP classes, and not additional releases of nonradioactive and the MELCOR calculations. The accident initiating aerosols from structural materials.) Finally, a total e ed was a pump seal LOCA with a total leak rate to s0.3% of the amtial inventory of the refractories (Ru, c ntainment of 2,839 litters per min (750 gpm) at normal Ce, La and U) are released. The release patterns are very primary system operating pressure. For the MELCOR similar to the release patterns predicted for the AG analysis, each primary system imp was provided with a sequence. Most of the La releases are predicted to occur e
m e pump sucha catml volmnes p2N, in the cavity, similar to the behavior of Ba and Te. All CV320, and CV420) sufficient to produce a 946 liters per of the Ru and almost all of the Cd releases are predicted mn( 0 gpm) leak rate at wrmal systens operating to occur in-vessel. The remaining classes, Mo, Ce, U pressure.
e STCP analysis utilized a single break sized and Sn, have most of their releases predicted to occur in-t aH w the total 2,8B Uten pu nun @0 gpm) How vessel, but a significant fraction occurs in the cavity.
rate. The containment fan coolers shifted from normal P*'*
8 **P" P*'* "
The released radionuclide distributions are also predicted atmosphere temperature rose above 383.7 K (105 F), at to fall into a few subdivisions. Except for the difference I min in the STCP calculation and 0.4 min in the that with no containment failure there is no release to the MELCOR calculation. By accident sequence definition, environment, the distribution patterns predicted by the operators began manual depressurization of the steam MELCOR for the S2D sequence resemble those obtamed generator secondaries at 30 min for both STCP and for the AG sequence. All of the noble gases (Class 1)
MELCOR, aiming to reach a target pressure of 1.31 MPa and iodine (Class 4) are m the containment by the end of (13.1 bar,190 psia) by 60 min. He STCP analysis the MELCOR simulation. Most of the Ba, Te and 12 predicted initial accumulator delivery at 40 min, while (295% of the amount released) are m the containment' MELCOR predicted it to occur at 38.8 min. As with the while all of the other classes also have most of their S2D calculation, the MELCOR accumulator flow was released inventory (~90% of the total released) m the divided into two distinct segments, with the initial containment.
delivery of 80 percent of the total accumulator inventory
- "*P The total mass of fission products released from the fuel predicted a second, and f~ mal accumulator discharge from is shown in Figure 5.3.49. About half the total release 656 min through 701 min, after the onset of core melt and 4
occurs during in-vessel core damage and melt election.
slumping. The STCP analysis modeled a single delivery He imcavity release primarily occurs before the of accumulator water that was completed at 80.5 min.
CORCON layer flip after 300 nun, with very little release at later times. Most of the fission products released are ggggg p
g found m control volumes, in either atmosphere or pool' and at 590.6 min for the MELCOR calculation. The and about 50-70% of the fission products m the control i
MELCOR nodalization of the core consisted of 3 radial NUREG/CR-6107 22
Resuhs and Comparisons rings and 10 axial nodes. MELCOR predicted gap at that level until the operator manually depressurized the release in radial ring I at 606.2 min, shortly after the system at 617 min, causing it to fall. By the time of onset of core uncovery. Ring 2 gap release was predicted lower head Gilure at 740 min, the primary pressure had at 608.6 min, with ring 3 following at 617.3 min.
decreased to approximately 0.5 MPa (5 bar, 73 psia).
MELCOR predicted cavity debris layer inversion at 900 After lower head failure, primary pressure was very close min.
to containment pressure.
Since the STCP code predicted a maximum containment ne primary system pressure predicted by STCP itaken pressure of 0.152 MPa (1.52 bar,22 psia) around the 700 from Ref.1, Vol. 6, Figure 4.2.41] is included in Figure min mark, the containment sprays never reached their 5.4.1 for comparison to the MELCOR calculation. The octuation setpoint of 0.172 MPa (1.72 bar,25 psia). On results from the two codes are qualitatively very similar, the other hand, MELCOR predicted the containment spray with the MELCOR primary system pressure predicted injection system to initiate at 851 min, followed shortly generally slightly lower than the STCP predicted response thereafter at 855 min by the containment spray for the first ~750 min (before vessel breach brings the recirculation system. The reason for their operation was RCS pressure to the containment pressure). The large e set of hydrogen deflagrations that occurred in the pressure spike at 700-750 min in the STCP result has only containment volumes, beginning at 849.3 min and a tiny counterpart in the MELCOR analysis. This continuing for 40 seconds, that drove the containment comparison between MELCOR and STCP predictions is pressure above the 0.172 MPa (1.72 bar,25 psia) spray very similar to the comparison for the S2D sequence initiation setpoint. The STCP calculation did not allow presented in Figure 5.3.1. As with the S2D sequence hydrogen combustion. A second set of two relatively results, the timing of the pressure spike corresponds to the weak hydrogen deflagrations occurred in the pressurizer, time between core collapse (at ~710 min for STCP) and at 961.6 min and 990.4 min, t.fter the lower head had bottom head dryout (at ~740 min for STCP), and is failed, barely causing a blip in the containment pressure.
likely due to boiling off the remaining lower plenum The MELCOR calculation predicted depletion of the water inventory. As in the AO sequence, MELCOR Refueling Water Storage Tank (RWST) at 944 min, at predicts the lower head failure very soon after predicting which point the containment spray injection system ceased core collapse (739.9 min and 739.0 min, respectively),
operation, leaving the containment spray recirculation and thus any water left in the lower plenum simply falls system, with its operable coolers, as the sole source of into the cavity; after lower head failure, the MELCOR containment heat removal. The STCP calculation was RCS pressure remains essentially.t the containment halted at 1,450 min, while the MELCOR run was stopped pressure.
at 1,667 min.
j Figure 5.4.2 gives primary temperatures in the reactor l
5.4.2 Primary System Behavior vessel downcomer and upper plenum control volumes.
Figure 5.4.3 provides a plot of the core exit gas Because of the relatively small leak rate from the primary temperature. From these plots it can be seen that the system, the S3D accident takes a significant period of primary temperatures fell from the 575 K (575"F) range time to develop, even though there is no active source of in the initial gages of the calculation, to approximately coolant injection. Figure 5.4.1 through 5.4.4 provide 480 K (404*F) by the end of the manual operation to information concerning primary system response based on depressurize the steam generators and the end of the first the MELCOR calculation, accumulator inventory delivery. Both downcomer and upper plenum temperatures remained in that range until Figure 5.4.1 shows the primary system pressure as it fell the beginning of core melting at 625 min, when the upper from normal operatirig pressure to the 8.0 MPa (80 bar, plenum temperature began to rise precipitously to 1,160 psia) range during the initial stages of the approximately 1,400 K (2,060"F) by 656 min. At that calculation, where it remained until the beginning of point, MELCOR predicted the remainder of the operator depressurization of the steam generator accumulators finally depleted, the upper plenum secondaries at 30 min. Successful completion of this temperature climbed quickly, reaching the 1,050 K procedure, along with delivery of water to the primary (1,430*F) range at the time of bottom head failure, 740 system from the passive accumulators, helped to reduce min. After that point, the downcomer and upper plenum the primary system pressure to the 1.6 MPa (16 bar,230 have been completely drained of coolant, for all practical 1
psia) range by 130 min. The primary pressure remained purposes.
Results and Comparisons Figure 5.4.4 gives a plot of the collapsed water levels in beginning at about 200 min. Significant core heatup began 3
the reactor vessel. The levels track the performance of after 590 min, when accelerated core uncovery began, and i
- the accumulators, since they are the only source of water the core damage process was quite rapid - MELCOR to the primary. As can be discerned from the plot, the predicted the start of core melting in the innermost ring at core remained covered until 591 min, when the upper 625 min and core collapse and lower head penetration plenum voided, and the collapsed water level dropped failure about 2 hr later.
below the top of the core. From that point, the collapsed water level fell off rather rapidly, and the core was Figure 5.4.10 shows the total masses of core materials completely voided by the time of core collapse and bottom (UO, Zircaloy and zire oxide, steel and steel oxide, and 2
head failure,739 min.
control rod poison) remaining in the vessel during the S3D transient. Almost all the core material is transferred Figure 5.4.4 is a plot of collapsed and swollen liquid to the cavity soon after vessel breach. All the UO is 2
levels in the reactor vessel, in the upper plenum, core and transferred to the cavity, as is most of the unoxidized 1
lower plenum. (Dotted lines are provided in the figure zircaloy, the oxides and the control rod poison; however, indicating the top-ofwore/ bottom-of-UP elevation at much of the structural steel in the lower plenum is 6.72197 m and the bottom-of-core / top-of-LP elevation at predicted to remain unmelted and in place even after 3.06437 m, for reference.) There was very little level vessel breach. Figure 5.4.11 shows the same information, swell predicted anywhere in the vessel except in the core.
but normalized by the initial masses of each material The core remained fully covered until the 960 min point present. (Note that the fractions of ZrO and steel oxide 2
in the accident, when the ECCS flow is shifted from cold use the initial masses of zircaloy and stainless steel, legs to hot legs. At that pcmt, the water level in both the respectively, as normalizing masses, because no oxides downcomer and the core fell below the top of the active are present initidly.)
fuel, even though significant liquid still remained in the upper plenum.. The collapsed liquid level in the core The temperature and mass of debris in the lower plenum dropped to about the core midplane, but the significant (i.e., on the lower head) are presented in Figures 5.4.12 level swell in the core kept the swollen level near the top and 5.4.13. There is only a brief period of time when a of the active fuel, and thus maintained core cooling, substantial mass of debris is found in the lower plenum, Water levels then remained about constant until b tween initial core plate failure and initial lower head containment failure at 3,540 min, when ECCS flow was penetration failure and ejection to the cavity.
lost. At that point, the water levels in the vessel dropped quickly, with all inventory lost at the point of vessel lower head failure,3,685.4 min.
5.4.4 Containment Response Integrated outflows from the primary system through the The containment pressure and temperature response, for pump seal leaks and through the vessel breach are given both the MELCOR and the STCP analyses, are given in in Figures 5.4.5 and 5.4.6, respectively; the outflows are Figure 5.4.14 and Figure 5.4.15. (The STCP results subdivided into liquid water, steam and hydrogen flows in were obtained from Figures 4.2.46 and 4.2.47 in Ref.1, both cases. Most of the RCS inventory is lost as liquid Vol. 6.) Although the timing of events varies between the water out the pump seal leaks until vessel failure occurs; two analyses, the progress of the accident is similar, liquid remaining in the lower pienum at the time of vessel qualitatively.
The major difference between the lower head failure is lost out the vessel breach to the containment response is driven by the fact that MELCOR cavity.
allowed hydrogen deflagrations to occur, while STCP did I
not. Each code predicted.a relatively benign rise in containment pressure during the initial minutes of the 5.4.3 Core Degradation calculations. The STCP calculation showed a containment pressure rise to just under 0.1 MPa (1 bar,14 psia) at 55 Figures 5.4.7 through 5.4.9 show cladding temperatures min, after which it leveled off and fell to the 0.09 MPa at various levels in the three radial rings during the core (0.9 bar,13 psia) range. The MELCOR code predicted damage period. The behavior in all three rings is very similar containment response, with an initial pressure rise similar, only slightly delayed in time in the outer rings to 0.08 MPa (0.8 bar,11.6 psia) and then a general due to lower power densities.
MELCOR predicted leveling off of the containment pressure as the primary intermittent core heatup in the uppermost axial level system coolant level slowly fell. Both codes predicted a NUREG/CR-6107 24
Results and Comparisons pronounced increase in containment pressure after the Figures 5.4.16 and 5.4.17 present the mole fractions of core uncovered, began to overheat, and the operators steam and concondensables in the cavity and containment manually depressurized the primary system via the dome control volumes, respectively. For the MELCOR PORV. For the STCP analysis, this occurred at 658 min, analysis, the containment was not steam inerted at the with the containment pressure rising from 0.09 MPa (0.9 time of lower head failure and debris ejection, and large bar,12.75 psia) to 0.11 MPa (1.1 bar,16.5 psia) by 687 hydrogen deltagrations occurred throughout the min, when core melting commenced. At that point in the containment at that point. Containment int grity was not STCP analysis, the containment pressure spiked upward, threatened by the pressure rise that resul'ed. Figures reaching 0.15 MPa (1.5 bar, 22 psia) by 717 min, the 5.4.18 through 5.4.24 provide information concerning time of core collapse into the lower head. Containment decay heat, both total and the portion connected with the pressure gradually trailed off afterwards, falling to 0.125 cavity, along with characteristics of the debris sesident in MPa (1.25 bar,18 psia) by the time of bottom head the cavity after lower head failure. At the end of the failure and the commencement of core-concrete MELCOR analysis, the corium debris temperatue was interaction, 850 min. Thereafter, with no containment approximately 1,650 K (2,510*F) and showing no signs or sprays in operation, the containment pressure rose changing very much, gradually to 0.15 MPa (1.5 bar, 22 psia) by the end of the calculation at 1,450 min.
5,4.5 Fission Product Transport and Release to the Environment After the PORV was manually opened at 617 min in the MELCOR analysis, containment pressure rose from 0.085 The STCP analysis did not look at source term releases MPa (0.85 bar,12.3 osia) to 0.1 MPa (I bar,14.8 psia) for the S3D accident. Thus, the following discussion by the time of core collapse into the lower head,739 min.
refers solely to MELCOR source term results. For From that point, containment pressure increased further reference Table 4.2.1 gives the list of the MELCOR to 0.14 MPs (1.4 bar, 20 psia) by 833 min, well after fission product classes and their total radioactive mass lower head failure and corium transfer to the cavity had inventories. Table 5.4.2 gives the radionuclide fractional occurred. The large hydrogen deflagrations that occurred distribution at the end of the MELCOR analysis,1,667 in the MELCOR calculation at that point caused the min.
Figures 5.4.25 through 5.4.36 show the containment pressure to spike upward to ~0.39 MPa (3.9 radionuclide mass fraction, according to fission product bar,56.6 psis), after which it decayed rapidly due to the class, released from the fuel in the in-vessel and ex-vessel cooling effect of the containment injection spray system pertions of the accident, accompanied by a trace showing that began operation at 851 min. By the time the injection the total of the two. Figures 5.4.37 through 5.4.48 give spray system had depleted the RWST at 944 min, the plots of radionuclide masses in the primary, containment, containment pressure had fallen to 0.08 MPa (0.8 bar, environment, and a sum total of all three, all normalized 11.6 psia). From that point onward, only the containment to the initial inventory of each class present in the core.
vecirculation spray system was functioning, and the As in the S2D analysis, since the containment was not as energy and containment began to repressurize predicted to fail, no releases to the environment occurred.
noncondensible gases were added from the core-concrete i
interaction.
By the end of the MELCOR accident Significant radionuclide releases from the fuel occurred at calculation, the containment pressure had climbed back up the onset of core melting, ~625 min, and continued to 0.115 MPs (1.15 bar,16.7 psia) and was changing through the remainder of the in-vessel portion of the very little, accident and on into the ex-vessel segment.
Transportation to the containment for the more volatile Figure 5.4.15 gives the containment atmosphere radionuclide classes was practically complete by the time temperature plots. The temperatures reflect a saturated of lower head failure at 740 min. Less volatile classes containment atmosphere after the initial stages of the showed significant release from the fuel during both the accident. As expected, the MELCOR temperature plot in-vessel and ex-vessel phases of the calculation. In shows a divergence in the temperature of the cavity general, radionuclide releases from the fuel were atmosphere after lower head failure and relocation of the completed by the 850 min mark, with the exception of corium to the cavity. The STCP temperature trace is Te, which exhibited a prolonged ex-vessel release that more benign since it does not reflect the effects of the lasted until the 1,170 min mark.
hydrogen deflagrations? hat are present in the MELCOR j
t plots.
25 NUREG/CR-6107 I
Results and Comparisons The same problem with ex vessel iodine release identified The released radionuclide distributions are also predicted in the AG and S2D sequences is found in the S3D to fall into a few subdivisions, generally different for the sequence results. Figures 5.4.25 and 5.4.26 show that S3D sequence than the patterns predicted for the AG and almost all of the Class I and Class 2 volatiles are released S2D sequences. All of the noble gases and iodine are from the fuel in the MELCOR calculation. For the S3D found in the containment by the end of the MELCOR sequence almost all that release occurs in-vessel, with simulation (as in the S2D simulation). Slightly more than s5% released ex-vessel in the cavity. Note that Figure half of the Cs and Ba released remain in the primary 5.4.28 shows a very similar release pattern for I in-vessel, system, and most (~75 %) of the Ru, Mo, Ce, U, Cd and but no additional release in the cavity. As discussed in Sn released remain in the primary system. Te and La are Sections 5.2.5 and 5.3.5, the
- missing
- iodine release is the only classes found mostly (~ 60-70 %) in containment found in Figure 5.4.26 in the >100% release total for at the end of the MELCOR calculation.
Cs. One would expect the Class 4 release to closely resemble the Class I and 2 results.
The total mass of fission products released from the fuel is shown in Figure 5.4.49.
Most of the total release Much larger in-vessel releases are predicted to occur occurs during in-vessel core damage and melt ejection.
during the S3D sequence than in the AG and S2D About 60% of the fission products released are found in sequences.
Assuming the correct iodine behavior, control volumes, in either atmosphere or pool, and about
~ 100% of the Class 1, Class 2 and (corrected) Class 4 70% of the fission products in the control volumes are radionuclide inventories are released, almost all in-vessel vapors rather than aerosols (mostly because aerosols settle (as in the AG and S2D sequences). The next major out and deposit onto heat structures more readily). There release fractions are of Cd and Sn, both with ~75%,
is significant (~40%) deposition of fission products onto much greater than found for the AG or S2D sequence, heat structures soon after release begins. The fractions of and almost all in-vessel, followed by Te (2:60%), about fission products in control volumes and on heat structures equally in-vessel and in the cavity, and Ba (s50%) and remains nearly constant through the latter portion of this Mo (s20%), both mostly in-vessel. (Note that all these
- sequence, include only the release of radioactive forms of these classes, and not additional nonradioactive aerosols from stmetural materials.) Finally, a total s2% of the refractories (Ru, Ce, La and U) are released.
Results and Comparisons Table 5.2.1 Sequence of Events Predicted during AG S;quence, Compared to STCP 1
Key Event Time (min)
STCP MELCOR j
Accident initiation
- 0.0 0.0 Containment injection sprays on 0.7 0.6 Containment recirculation sprays on 6.1 5.1 ECCS injection on, (HPIS/LPIS) 0.4 Accumulators depleted 25.1 1.0 ECCS recirculation on, cold legs 29.0 50.0 RWST depleted 29.0 50.0 ECCS recirculation shift to hot legs 960.0 Containment failure 3,054.2 3,540.0 ECCS off 3,055.2 3,541,7 Core uncovery begins 3,080.6 3,570.2 Begin zircaloy oxidation 3,619.6 Gap release, Ring-1 3,621.5 Gap release, Ring-2 3,626.4 Gap release, Ring-3 3,641.6 Core melt t.ts 3,155.6 3,665.0 Core slump
-3.206.6 3,680.0 3,209.2 3,684.3 (partial) g, yg,p ring-1 Bottom head dryout 3,237.6 3,371.6 3,685.4 (partial)
Bottom head failure ring-1 Commence debris ejection 3,685.4 Begin concrete attack 3,371.6
-3,686.9 End of calculation 3.973.1 5,000.0 j
'l l
l 27 NUREG/CR-6107
Results and Comparisons 20 C
Upper Head IO
~
~
0 Downcomer i
Core 16 n2 14 E
'O 12 8
s O
g 10 E
o.
8 x
U o
E o
c 6
n.
4 2 N 0
T~
00'
'\\
er 0
1 2
3 4
5 3
Time (10 min)
Surry AG (HL LBLOCA)
CWDRDCONK 3/23/93 17:35:04 MELCOR IBM-RISC Figure 5.2.1 Primary System Pressures Predicted during AG Sequence NUREG/CR4107 28
l:
Results and Comparisons 850
,n C
Downcomer '
~
~
0 Upper Plenum 750 700 d )
E 8
650 u
.2 2
600' -
E.
l i 5
550 s.-
x b
500p 5
E 450 u
400Il 13' o
I l 350 I
i t
300 0
1 2
3 4
5' 3
Time (10 min)
Surry AG _(HL LBLOCA)
CWDRDCQNK 3/23/93 17:35:04 MELCOR IBM-RISC Figure 5.2.2 Primary System Temperatures, in Downcomer and in Upper Plenum, Predicted during AG Sequence 29 NUREG/CR4107
Results and Comparisons f
2.2-
=
Upper Plenum
)
t
- 2. 0 '
- o-Top Core Level (Ring 1)
~
- -e - Top Core Level (Ring 2)
P
[
1.8
--E--
Top Core Level (Ring 3)
~
9-l
- 1. 6 8
.p b
j 3
1.4 Eo.
1.2
)
s ik mg 1.O
[(f',,
-e -
g t
se o
b 0.8
$ 83, A,
N a
%a j
u u
-O
- 0. 6 :c A_wo.~ -rz
=y % '_-
l l 4
~'"
0.41 41 :::
n
~
0.2 0
1 2
3 4
5 h
3 Time (10 min)
Surry AG (HL LBLOCA)
CWDRDCONK 3/23/93 17:35:04 MELCOR IBM-RISC -
Figure 5.2.3 Core Exit Gas Temperatures, in Upper Plenum and in Uppermost Core Cells, Predicted during AG Sequence NUREG/CR-6107 30
--r
L i
Results and Comparisons
)
I
'l 16
--e--
Lower Plenum.(Swollen)
=
Lower Plenum-(Collapsed) j4
--e--
Core (Swollen)
Core (Collapsed)
I2
~
Upper Plenum (Swollen)
~
--A--
Upper -Plenum (Collapsed).
i E
10 v
a
. g.
h-$ f f %
6 j
8i r
-6 a
l l
4 0
=
=
=
_c
-]
2 l11
' " C'-
': 0 0
0-1 2
3 4-5-
3 Time (10. min)
Surry ' AG (HL LBLOCA)
CWDRDCONK 3/23/93 17:35:04 MELCOR IBM-RISC Figure 5.2.4 Reactor Vessel Liquid Levels Predicted during AG Sequence 31 NUREG/CR-6107 '
Results and Comparisons l
60 55 50 R
l
.f 45 1
oG 40 1
%o 35
=no 30 5*
25 cn F
20 a
-l o
15 c
10 5
0
=
' - e ' = '- ^ '
- -' - - * -
- v - ~ - * -
0 1
2 3
4
-5 3
Pool (Break)
Time (10 min)
Surry AG '(HL LBLOCA)
-- e--
steam (Break)~
j CWDRDCONK 3/23/93 17:35:04 MELCOR IBM-RIS ""o H2 (Break)
J Figure 5.2.5 Integrated Outflows of Liquid, Steam and Hydrogen through the Hot Leg Break Predicted during AG Sequence NUREG/CR-6107 32 i
=
L A
4 Results and Comparisons I
I I
I I
I I
I i
12.5 N
7.5 g
x m5 2.5 ny
[ [
[
((
[
[ ;
C
[
......D...........
9
's -2.5 X
~~
O y
\\
n O
\\
8 -7.5 4
a t
s T
\\
ng-12.5
\\
\\m
\\\\-
-17.5 s
' 3
-22.5 O
1 2
3 4
5 3
Pool Time (10 min)
~~*~~N'*
Surry AG (HL LBLOCA)
""U '" H2 CWDRDCONK 3/23/93 17:35:04 MELCOR-IBM-RISC Figure 5.2.6 Integrated Outflows of Liquid, Steam and Hydrogen through the Vessel Breach Predicted during AG Sequence 33 NUREG/CR-6107
Results and Comparisons i
i
'I 2.50
-i i
i i
i i.
i Node 104-1 2.25 Node 105 2.
Node 106 4
Node 107 I
'2.00 2
' Node 108.
.1.75
'~
0 Node 109 -
g v
O Node 110 g
1.50 c.
Node 111
- s c
Node 112
(-1.25 Node 113 E
m H
1.00 o>
.E
- '8 0.75
_oo 0.50 m.
_-- =.- _
m=
0.25 O'A :
~0.00 3.50 3.55 3.60
'3.65 3'. -7 0
'3'.75 I
3 Time (10 min)
Surrye AG' (HL LBLOCA)
CWDRDCONK' 3/23/93 17:35:04 MELCOR IBM-RISC
-l Figure 5.2.7 Core Ring 1 Clad Temperatures Predicted during AG Sequence NUREG/CR-6107 34
~..,.
- 1.
Results and Comparisons 2.50
=
Node 204 2.25 No'de 205 1
Node 206 2.00 Node 207 2
Node 208
- g 1.75 C
Node 209 I
v C.
Node 210 n
g 1.50 a
Node 211 o
Node 212
.( 1.25 Node 213
~
Eo H
1.00
.E_".
1 0.75 2o O.50 ;
g g;_
0.25 0.00
'3.50 3.55 3.60 3.65-3.70 3.75 3
Time (10 min)
Surry AG (HL LBLOCA)
LCWDRDCONK 3/23/93-17:35:04 MELCOR IBM-RISC Figure 5.2.8 Core Ring 2 Clad Temperatures Predicted during AG Sequence i
35 NUREG/CR-6107 a
i Results and Comparisons
-i
'-t
'i i
2.50 i
i i
i i
i i
=
Node'304 2.25 yoe 3o3 1
Node 306 2.00 Node 307
[
~
2
'T Node 308
._ "g'1.75 C
Node 309 1 i
~
( 1.50 0
Node 310 g.
1 Node 311
~
s
~Ei Node 312 i 1.25 gog, 333 Eo*
1.00
.E_
E 0.75
_9 0
0.50.:
0.25
. 0 '. 0 0 3.50 3.55 3.-60 3.65-3.70 3. 7.51 3
Time (10 min)
Surry-AG- (HL LBLOCA)
.CWDRDCQNK 3/23/93 17:35:04 MELCOR IBM-RISC Figure 5.2,9 Core Ring 3 Clad Temperatures Predicted during AG Sequence NUREG/CR 6707 36
Results and Comparisons 90
=
UO2 80
- e-Ziracioy
-- E--
Zire Oxide
- * - steel-3 70
--w-Steel Oxide mcn
_v
-. -+. - CRP 60
.m9 v
II g
g 50 E
2 40 3._
.o
___S e
30 t>o 20 a____
___4_
10 0
Y~E
- & ' ' 7-
-- 2-- !
=
^
^
3.5 3.7 3.9 4.1 4.3 4.5 4.7 4.9 h
3 Time (10 min Surry AG (HL LBLOCA)
CWDRDCQNK 3/23/93 17:35:04 MELCOR IBM-RISC Figure 5.2.10 Core Total Material Masses Predicted during AG Sequence 37 NUREG/CR4107 i
Results and Comparisons 1.0 is a i
i i
I UO2 i
' L i
_._. ziracioy -
0.9 li I
-- E-- Zirc 0xide g
0.8 S _ __ __ 4 _ __ _ __ 4 __._
e
_4_
si,,i o
i Steel Oxide
- - = - -
E 0.7
_._p.-
CRP i 1 T _._._._.. +._.
g 0.6 l
E 0.5 l
e"
-a mem o
0.4 2
~oc:
0.3
.9
o~
E 0.2 u.
Wit __ _ _ _ _, _ _ _ _ _ _ _ _, _ _ _ _. _, _ _ _ _ _ + -
0.1 l
\\
_ _ i.Mc s _. A..: -.:. s -R _.c = s. U _, _ w W.
_:. C 0.0 3.5 3.7 3.9 4.1 4.3 4.5 4.7 4.9 3
Time (10 min Surry AG (HL LBLOCA)
CWDRDCONK 3/23/93 17:35:04 MELCOR IBM-RISC i
Figure 5.2.11 Core Fractional Material Masses Predicted during AG Sequence NUREG/CR-6107 38 I
.j
Results and Comparisons q
u k
l'5 I
I I
i i
I i
i i
i I
I I
i N
l>
[l 35
=
Ring 1 (COR.101) n d
O Ring 2 (COR.201)
Ring 3 (COR.301) 30 mO p
,,f o
25 i p v
ne' m
D 2
20 o
oe m
.E!
15 ie li o
H e-10 m
s i O
u i W 5
Y v
v v
^'-'
s 0
3.5 3.7 3.9 4.1 4.3 4.5 4.7 4.9 h
3 Tirne (10 min)
Surry AG- (HL' LBLOCA)
L, CWDRDCONK 3/23/93 17:35:04 MELCOR IBM-RISC O
b g
Figure 5.2.12 Lcrwer Plenum Debris Bcxl Masses Predicted during AG Sequence 39 NUREG/CR-6107 y
i-
Results and Comparisons i
2.25
--m-Ring 1 (COR.101)'
ll
---+- Ring 2 (COR.201) 2.00 Ring 3 (COR.301) mx 1.75 O
0 m
2 1.50 l b 2
\\
E hl E
1.25 E
O v
1.00 c8
.m
'E 0.75 E
E 0.50 0
0.25 9
0.00 0'=
':l:
'='
'=
'=
3.5 3.7 3.9 4.1 4.3 4.5 4.7
-4.9 3
Time (10 min)
Surry AG -(HL LBLOCA)
CWDRDCQNK 3/23/93 17:35:04 MELCOR IBM-RISC Figure 5.2.13 Lower Plenum Debris Bed Temperatures Predicted during AG Sequence NUREGICR-6107 40
l Results and Comparisons' s
I l
l 1.0 i
i a
i i
i-O Basement
- 0. 9 -
Cavity
~
SG Cubicles
/
0*8 2
Przr Cubicle
.f
^
m o.
II Dome o.
/
07 STCP
- II.
o v
../
E 0.6 us M
m l
i E
0.5 o_
./
/
5 0.4
~
E
/
i C
- ~
2 0', 3 :e e
o 9
ir o
e 0.2 d
/
i 1b g.-
0.1 e
'l l
i i
i i
e i
0.0 0
1 2
3
'4 5
3 Surry AG~ (HL LBLOCA)_.
Time (10 min)
CWDRDCQNK 3/23/93 17:35:04- 'MELCOR IBM-RISC Figure 5.2.14 Containment System Pressures Predicted during AG Sequence 41 NUREG/CR4107
Results and Comparisons 500 i
i i
i i
i 480
' r 52 460'E m
E 440
.2 I f
- 8. -
420 3 E-E I >
y 4
lu 400' "
- n a
E u,
t-g
! 4' 380[ l-./
0_c
^^
Ee f
y 5
360 S.!
O B 8'**"I
- .1 a
Cavity
'.5_
a 340 1
7 SG Cubicles ~
Przr Cubicle 320 x Dome.
......... STCP 300-0 1
2 3
4 5
H 3
' Time (10 min)
Surry. AG (HL LBLOCA)
CWDRDCONK 3/23/93 17:35:04 MELCOR IBM-RISC I
Figure 5.2.15 Containment System Atmosphere Temperatures Predicted during AG Sequence NUREG/CR-6107 42 2
- ~. _
i l
Results and Comparisons j
4 i
1.0
, g..,...
k I' O.9-
_.)
,,,..3' 0.8 l..D,.-
0.7 C
/
._9 o
/
-._e..-
steam o
0.6 8
- o-N2 e
o g j
/
e 0.5
\\/
- 4
- 02 3
'5/
- - E- - H2 m
t) 2-0.4 o
d\\
o 0. 3_ tt!
\\
W s
i O m
- 0. 2 It s
N 1
n A
N t
0.1 N
'e t-l
~$ _
~ h - -d
'0
- 1 0.0 I
0 1
2 3
4 5
3 Time (10 min)
Surry AG (HL LBLOCA)
CWDRDCQNK 3/23/93 17:35:04 MELCOR IBM-RISC Figure 5.2.16 Cavity Steam and Noncondensable Mole Fractions Predicted during AG Sequence-43 NUREG/CR-6107
Results and Comparisons I,.
160 i
Total
- o-in core -
140 15 h-in C avity-0
--E--
on Structures 120
_._e.
In Atmosphere
--v-
- in Pool 9
100 a
o
'15=
80 c
II xO
[
60,y 4-40 4
20 0
=
c 0
01 ':
'0 1 Si W
51 t "; t
- C ; ^
0 1
2 3
4 5
t-3 Time (10 min)
Surry-A'G (HL LBLOCA)
CWDRDCONK 3/23/93 17:35:04 MELCOR IBM-RISC Figure 5.2.17 Decay Heat Predicted during AG Sequence NUREG/CR4107 4,g a
\\
i Results and Comparisons 200 i
i i
i i
i
- m-Total added by COR 180
~
0 Total in CAV
-- A-- - Gas released in CAV
^
160
~
_.H - Concrete ablated in CAV 140
~
g
,;Fg 120
--m -- - -
--a.
I y
g 100 U-s 3 -
80 TU 60 r,
-n IV
/
40
/
t o
5 20
____a--------
'i,,'
0 1 :'
0
'1 :t 0
'l 2.5 3.0
'3.5 4.0-4. 5-
-5.0 3
. Time- (10 min)
Surry. AG.(HL LBLOCA)
CWDRDCONK 3/23/93 17:35:04 MELCOR IBM-RISC
]
Figure 5.2.18 Total Cavity Masses in Cavity Predicted during AG Sequence
.m 45 NUREG/CR-6107 w-4 43
Results and Comparisons-160 u
0 H0X L
1 LOX 140 i
~
MET,
120 e
v y
100 o
1 5
(
p 80 a
.3 60 o
==
g 40 o
o 20 9
0 7 0' 70' i
'7:T' -
c
0 2.5 3.0 3.5 4.0 4.5 5.0 3
Time (10 min)
'Surry ' AG (HL LBLOCA)
CWDRDCONK 3/23/93 17:35:04 MELCOR IBM-RISC Figure 5.2.19 Cavity Layer Masses Predicted during AG Sequence NUREG/CR-6107 46
Results and Comparisons 1(
2.25 i
i i.
i i
i O
H0X.
<7 a
t.0X 2.00 1
2 MET m
g 9
1.75 g
1 2
1.50 j
E E.
')
1.25
.s y
u E 1.00
.S m5 0.75 8
b 0. 5 0' 5:
l a
0o 0.25 0.00 7 0' i
'70' i
' -' 0 0
'0 2.5 3.0 3.5 4'. 0 4.5 5.0 3
Time (10 min)
-Surry AG (HL LBLOCA)
'CWDRDCQNK 3/23/93 17:35:04 MELCOR IBM-RISC Figure 5.2.20 Cavity layer Temperatures Predicted during AG Sequence 47 NUREG/CR-6107
}
- Results and Comparisons 60 55 C
Dec y Heat O
Chemical Reactions -
50 0
45 40 i
v g
35 E
g 30 v>
g 25 I
20 15 o
o 10
=
5 t
0
-5 2.5 3.0 3.5 4.0 4.5 5.0 3
Time (10 min)
Surry AG (HL LBLOCA) j CWDRDCQNK 3/23/93 17:35:04 MELCOR IBM-RISC i
Figure 5.2.21 Decay Heat and Chemical Energy in Ca ity Predicted during AG Sequence NUREG/CR-6107 48 l
Results and Comparisons Cavity Minimum Depth 1.4 1.3 E
1.2 v
1.1 1.0 Cavity Maximum Radius 4.450 4.425 4.400 4.375 E"4.350 4.325 4.300 4.275 2.5 3.0 3.5 4.0 4.5 5.0 3
Time (10 min)
Surry AG (HL LBLOCA)
CWDRDCONK 3/23/93 17:35:04 MELCOR IBM-RISC l
1 Figure 5.2.22 Cavity Maximum Radius and Minimum Depth Predicted during AG Sequence 49 NUREG/CR-6107
-l
'Results and Comparisons
- )
1 i
.l i
i e
i i
i i
i i
i 7
'3 1
=
Total from Cavity
- e-H2 from Cavity y'
6
- * - H2O from Cavity
~
^
p
/
--K--
C0 from Cavity "o
,/
c 5
- -+- - CO2 from Cavity
- o-H2 from Core v
'g
--E--
CO. from Core f
i o
_o_
4 I
-(- - CO2 from Core
.O ct
- - v- - ; CH4 from Core il m
o
.r o
3 w
q o
Eo 2
CE ll 1
4l 7
0
^ -^-
--=2-2-
M
^' r -
2.5 3.0 3.5 4.0 4.5 5.0 i
3 Time (10 min)
Surry AG (HL LBLOCA)
CWDRDCONK 3/23/93 17:35:04 MELCOR IBM-RISC I
i Figure 5.2.23 Gas Generation Predicted in Core and in Cavity during AG Sequence NUREG/CR-6107 r
50
Results and Comparisons Table 5.2.2 Radionuclide Distribution in Core, RCS and Cavity Predicted at 5,000 min for AG Sequence Radionuclide Core RCS Cavity Species Group and Representative Element MELCOR STCP MELCOR STCP MELCOR STCP.
Noble Gases, Xe 8.91E-03 2.93E-04 0
Alkali Metals, Cs 8.61E-03 0.127 0.13
-0 1.6E44 Alkaline Earths, Ba 1.14E-02 5.74E-03 5.0E-03 0.834 0.98 Italogens, I 1.59E-02 5.13E-04 0.13 0
1.5E-04 Chalcogens, Te 1.14 E-02 7.13 E-03 0.15 0.755 0.14
- Platinoids, Ru 1.15 E-02 1.20E-04 3.8E-07 0.988 1.0 Transition Metals, Mo 1.14E-02 5.69E-03 0.958 Tetravalents, Ce 1.15E-02 4.72E-06 0
0.988 1.0 Trivalents, La 1.15E-02 6.41 E-06 4.0E-08 0.988 0.99 Uranium, U l.53 E-02 5.57E-06 0.985 1.13E-02 1.59E-02 0.928
? in u Metals,Cd y
Results and Comparisons Table 5.2.3 Radionuclide Distribution in Containment and Environment Predicted at 5,000 min for AG Sequence
"",'[
Containment Environment Radionuclide Species Group and Representative Element STCP MELCOR STCP MELCOR STCP ELCOR Noble Gases, Xe 6.75E-05 0.991 0.998 0.99 1.00 Alkali Metals, Cs 0.779 0.28 8.52E-02 0.57 0.86 0.85 Alkaline Earths, Ba 0.145 7.3 E-03 4.03 E-03 1.4E-02 0.15 2.1E42 Halogens, I 1.16E-04 0.28 0.983 0.58 0.98 0.86 Chalcogens, Te 0.220 0.24 6.32E-03 0.47 0.23 0.71 Platinoids, Ru 2.78E-04 4.2E-07 7.61E-05 7.9E-07 3.5E-04 1.2E-06 Transition Metals, Mo 2.18E-02 2.87E-03 2.5E-02 Tetravalents, Ce 1.38E-05 1.8E-05 2.59E-06 4.8E-05 1.6E-05 6.6E-05 Trivalents, La 1.94E-04 6.2E-05 5.82E-06 1.6E-04 2.0E-04 2.2E44 Uranium, U 2.57E-05 4.30E-06 3.0E-05 6M (5M2 i Gr Metals, Cd tt:t20 Metais, S.
4.368-o2 9.678-o>
s.aso2 NUREG/CR-6107 52
Results and Comparisons -
1 Class 1 (Xe) 100 a
u 90 T
8 80 c
_E 70 B
i 60 r
r) v__
_ _ v _. _ _ _,. _
50 sa 9____4____.__
40-
'r E
l
.8
)I r
30 3
I 8
I
.o 20 l
e
,1 10 I
J
0 Ct l'
ct l'
c 2.5 3.0 3.5 4.0 4.5 5.0 y
Time (10 min)
- v-Primary -
3 Surry AG (HL LBLOCA)
- -a - Cavity c
Total CWDRDCONK 3/23/93 17:35:04 MELCOR IBM-RISC Figure 5.2.24 Release of Class 1 (Xe) Noble Gas Radionuclides from Fuel in Core and in Cavity Predicted during AG Sequence, as Percentage of Initial Inventory in Core 53 NUREG/C:14107
l Results and Comparisons Class 2 (Cs) 110 i
i i
i-i
~
d 100 b
T 90 E-c*
80 s
~s 70
.T
_C_.
60 a
g _ _ _,. _ _ _ _.,.
v
__8 50
,s----u--
w 5
40 7
I 4:
I U
/
T 30 b
8 20
/
e
/
i l
10
/
0 0t e'
at l'
0' 2.5 3.0 3.5 4.0 4.5 5.0-3
- v-Primary Time (10 min)
- + - Cavity -
Surry AG (HL LBLOCA) o Total CWDRDCQNK 3/23/93 17:35:04 MELCOR IBM-RISC Figure 5.2.25 Release of Class 2 (Cs) Alkali Metal Radionuclides from Fuel in Core and in Cavity Predicted during AG Sequence, as Percentage of Initial Inventory in Core j
- ~r
Results and Comparisons--
l
- l i
Class 3 (Ba) 16 i
14 g
--w----
L
.O A
S 12
_E_
A:
10 g
O 8
2tf
(
U E
6 O
.h I
1 v
E-4 l
j O
i S-l e
/
2 7 - - -,. - - -
q r
./
0 Ct l'
Ot l'
2.5 3.0 3.5 4.0 4.5 5.0-3
- v-Primary Time (10 min)
-- + - cmHy
.'Surry AG (HL LBLOCA)
Total CWDRDCONK 3l23/93 17:35:04 MELCOR IBM-RISC -
m l
Figure 5.2.26 Release of Class 3 (Ba) Alkaline Earth Radionuclides from Fuel in Core and in Cavity Predicted during AG Sequence, as Percentage of Initial Inventory in Core 55 NUREG/CR-6107.
Results and' Comparisons Class 4 (I) 60 i
e i
i i
e i
=
55 P
T 50 uS fr g
45 E
40
.9 3i 35 5
30
-ua u.
25 E
20
]
m 8
15 g
tr-10 5
0 Ct Ct d'
^
^'
^
2.5 3.0 3.5 4.0 4.5 5. 0-3
- v-Primary '
T.ime (10 m. )
in
- -e - Cavity.
Surry AG (HL LBLOCA) gg CWDRDCONK 3/23/93 17:35:04 MELCOR IBM-RISC 4
Figure 5.2.27 Release of Class 4 (I) Halogen Radionuclides from Fuel in Core and in Cavity Predicted during AG Sequence, as Percentage of Initial Inventory in Core NUREG/CR 6107 56 j
i J
Results and Comparisons
.)
Class 5 (Te) 25.0-i i
i i
i i
i 22.5 m
$ 20.0
~
~
b
/
s 17.5
/
T:i 5__ 15.0 I
A a
I
" 12.5 T
l E.
10.0 E
is 8
7.5 T
l 8
F m
5.0 l
E g
/
2.5 r
/
0.0 Ct l'
Ot l' N" 2.5 3.0 3.5 4.0 4.5 5.0 3
~ " ~ ~ 'I* 'Y Time (10 min)
- -e - Cavity -
.Surry AG (HL LBLOCA)
Total CWDRDCONK 3/23/93 17:35:04 MELCOR IBM-RISC q
j l
Figure 5.2.28 Release of Class 5 (Te) Chalcogen Radionuclids from Fuel in Core and in Cavity Predicted during AG l
Sequence, as Percentage of Initial Inventory in Core 1
57 NUREG/CR-6107 1
- Results and Comparisons Class 6 (Ru) 50 i
i i
i i
i i
i i
=
=
f=
45 2
y
(,
'c 40 O
_E 35
.9
.~
C 30 e r e<
m I
52 25 v
~52 20 E
r j
15 y
10
_c 7
5 0
Ct l'
Ct l'
0 i'
i' i
2.5 3.0 3.5 4.0 4.5 5.0 Time (10? min)
- v-Primary
- Surry AG (HL LBLOCA)
-- 4 -- Cany 2
CWDRDCONK 3/23/93 17:35:04 MELCOR IBM-RISC
't Figure 5.2.29 Release of Class 6 (Ru) Platinoid Radionuclides from Fuel in Cote and in Cavity Predicted during AG Sequence, as Percentage of Initial Inventory ir Core l
' NUREG/CR-6107 58 l-
l Results and Comparisons
'l Class 7 (Mo) 3.25 i
i i
C 3
00 2.75 mb
$ 2.50
?5 2.25 5E 2.00 E
9-y-
-9 a
u 1.75 v
].1.50 7
u..
e
- 1. 2 5.
p __._ __ a__ -
/
1 00 a
i E
I 8 0.75 A
y E 0.50 I
t I
0.25
-h I '
A 0.00 0t e'
Ct l'
d 2.5 3.0 3.5 4.0 4.5 5.0 Time (10 min)
- "- P'~I* 'Y 3
i CovHy Surry AG (HL LBLOCA)
IBM-RISC Total CWDRDCONK 3/23/93 17:35:04 MELCOR Figure 5.2.30 Release of Class 7 (Mo) Early Transition Element Radionuclides from Fuel in Core and in Cavity Predicted during AG Sequence, as Percentage of Initial Inventory in Core 59 NUREG/CR-6107
i
( '
Results and Comparisons 1
Class 8 (Ce) 2.25 2.00 r.
m L
b c
.2l 1.75 s
=
(
E 1.50
_e ir a
1.25 m
l9 v
1.00 7
if
@ 0.75 i t
.t-
] 0.50 g
4-3
/
n: 0.25 7
/
f 0.00
=t l'
at c'
di 1.-
i e
i 2.5 3.0 3.5 4.0 4.5 5.0 Time (10 min)
- v-Primary.
3 Surry AG (HL LBLOCA)
- Cavity c
Total CWDRDCQNK 3/23/93 17:35:04 MELCOR IBM-RISC f
w mmmmmmmmmmmmmmmmmmm Figure 5.2.31 Release of Class 8 (Ce) Tetravalent Radionuclides from Fuel in Core and in Cavity Predicted during AG Sequence, as Percentage of Initial Inventory in Core NUREG/CR-6107 60 3
Results and Comparisons _
Class 9 (La) 22.5 rr 20.0
.mb o
Cg 17.5 g
-a--
.s 3
15.0 E
f 12.5 I
oG 10.0 3
I E
7.5 e
to
' l I
5.0 I
8 2
=,
I - - v-- - - v-f m
2.5
/
0.0 0t l'
Ct l'
['
2.5 3.0 3.5 4.0 4.5 5.0 Time (10 min)
- v-Primary 3 cmHy -
Surry AG (HL LBLOCA) o Total CWDRDCQNK 3/23/93 17:35:04 MELCOR IBM-RISC Figure 5.2.32 Release of Class 9 (I.a) Trivalent Radionuclides from Fuel in Core and in Cavity Predicted during AG Sequence, as Percentage of Initial Inventory in Core 61 NUREGICR-6107
E Results and Comparisons Class 10 (U) 4.5 m -
4,0-c D
o C
-3.5 e
_E j
-9 3
3.0 f
-*g.
tr M
2.5 m
-ig v
2.0 v
K
'E 1.5 8
mg
-1. 0 u
g 4
w
.y o:
0.5 t
r 1
0.0 Ct l'
ct l'
d 2.5 3.0 3.5 4.0 4.5 50 Time (10 min)
- v-Primary.
3 Surry AG (HL LBLOCA)
- + - c avity CWDRDCQNK 3/23/93 17:35:04 MELCOR IBM-RISC
-NI C
==mmmmmmmmmmmmmmme i
Figure 5.2.33. Release of Class 10 (U) Uranium Radionuclides from Fuel in Core and in Cavity Predicted during AG Sequence, as Percentage of Initial Inventory in Core
Results and Comparisons Class II (Cd)
-6 5
i i
i i
i i
i.
i i
5 - --
6.0 g
g 5.5 o
5.0 c
4.5
'5
!T EE 4.0
_C 4
w 3.5 v
~5 3.0 u.
E 2.5 E-2.0 o
1
.\\
m
-.o 1.5 m
- 1. 0-r 0.5
- r -a, -
r 0.0 0.t s'
ct i'
d 2.5-3.0 3.5 4.0 4.5
- 5. 0L Time (10 min)
- v-Primary 3
Surry AG (HL LBLOCA)
- 6 cavity --
c Total CWDRDCQNK 3/23/93 17:35:04 MELCOR IBM-RISC mammem mmmmmmmmmmu Figure 5.2.34 Release of Class 11 (Cd) More Volatile Main Group Radionuclides from Fuel in Core and in Cavity Predicted during AG Sequence, as Percentage 'of Initial Inventory in Core 63 NUREG/CR-6107
.Results and Comparisons Class 12 (Sn) 7.0 6.5
~
b 6.0
-v - -
w-
,p u2 5.5 C
I 5.0 s
,3 4.5 i r 5
4.0 w
3.5 eif 3.0 2.5 k
v 2.0 8
g 1.5 1.0 I
0.5 1
0.0 at l'
at l'
d
- 2.5 3.0 3.5 4.0 4.5 5.0 i
Time (10 min)
- v-Primory 3
Surry AG (HL LBLOCA)
-- + -- cow y.
c Total CWDRDCQNK 3/23/93 17:35:04 MELCOR IBM-RISC Figure 5.2.35 Release of Class 12 (Sn) Less Volatile Main Group Radionuclides from Fuel in Core and in Cavity Predicted 1
during AG Sequence, as Percentage ofInitialInventory in Core l
NUREG/CR 6107 64 i
l Results and Comparisons Class 1 (Xe) 100
/
Total Released
/
90-
- o-Primary
/
- e - Containment
/
o
--A--
Environment 4
j 80 s
_C 1
8 70
-O I
n E
l
~C n
60 e
A E
9 50 5
o
_o "1
5 40 I
b
. i 1
e 30 Il 1
l 3
,1 o
1I E
20
.9 in
\\
i t
i O
g
\\
i g
R 10 t
N
^ ' ' "'
^^^"'
0 2.5 3.0 3.5 4.0 4.5 5.0 4
Time (10 min)-
1 3
Surry 'AG (HL LBLOCA)
CWDRDCONK 3/23/93 17:35:04 MELCOR IBM-RISC Figure 5.2.36 Distribution of Class 1 (Xe) Noble Gas Radionuclides in Primary System, Containment and Environment Predicted during AG Sequence, as Percentage ofInitialInventory in Core 65 NUREG/CR-6107
Results and Comparisons i
Class 2 '(Cs)'
110 i
i i
i i
i i
Total Released f;
100
^
-D-Primary x
hi
- -e - Containment 90
' @~
--A--
Environment t
- - - -- a 5
80 f
.o l
5 70 6
/
a f
i 60 C
.e
/
- 1 3
50
/.
S P
.6
.2 40 7
/
O I>
eR 30
/
_g 9
1 C
1(
.e 20 m
cE r s- - - D-
-D-
- i 10
',,_______+_______4____.:
0 0 tic' ct c'
d
2.5 3.0 3.5 4.0 4.5 5.0
)
Time (10 min) 3 Surry ' AG (HL LBLOCA)
CWDRDCONK 3/23/93 17:35:04 MELCOR IBM-RISC
-i Figure 5.2.37 Distribution of Class 2 (Cs) Alkali Metal Radionuclides in Primary System, Containment and Environment Predicted during AG Sequence, as Percentage ofInitialInventory in Core NUREG/CR-6107 66 1
i
'1
Results and Comparisons -
4 i
Class 3 (Bo) 16
~
Total Released C
- O- - Primary k "~ ~ ~
~~~-
g j4 o_
-- e - Containment O
E
--A---
Environment
_E_
12 oE5 10 8
E 8
=a
.e 6
1 o
o e
m Ti
.4 I
E
/
o5
/-
e 2
j 7
J' @ =, := - iik - - - - - - -@=
=
0
--e-t i O '
O t c'
~
2.5 3.0 3.5 4.0 4.5-5.0 3
Time (10 min)
Surry AG (HL LBLOCA)
CWDRDCONK 3/23/93 17:35:04 MELCOR IBM-RISC Figure 5.2.38 Distribution of Class 3 (Ba) Alkaline Earth Radionuclides in Primary System, Containment and Environment during AG Sequence, as Percentage of Initial Inventory in Core 67 NUREG/CR-6107
i Results and Comparisons -
l
-l
- q Class 4 (I) 60
"'I' **d 55
^
I
'7
~
__. g___ Primary
- + - containment
/
o 50
--A--
Environment f
E
,7
_t -
45 l
I
- E 40 dl
- =
i
~
1I w
35 4
ft YI 8
30 5
i f
25
,4 E
it -
5 31 20 E
'I in 15 15
.' 6 a
8
$\\
- 6 10 g
O
'[
\\
5 g
d} ' c 0
0 t'c' 0 tic'
'c:
'c 2.5 3.0 3.5 4.0 4.5 5.0 3
Time (10 min)
Surry AG (HL LBLOCA)
CWDRDCONK 3/23/93 17:35:04 MELCOR IBM-RISC Figure 5.2.39 Distribution of Class 4 (I) Halogen Radionuclides in Primary System, Containment and Environment Predicted during AG Sequence, as Percentage of Initial Inventory in Core NUREG/CR-6107 68
~.
,)
Results and Comparisons Class 5. (Te) i 25.0 7
Total Released 22.5-
- a-Primary
. ~.
o-
- e - C~ontainment
{o er '
20.0
--A--
Environment
/
/
17.5 f
g E
7 C
o 15.0
,8.12.5 3n E-10.0 1
.n r
O
~
7.5 e
.m
=
8g 5.0 l
A
/
__f 2.5 7
J ~= i +
i-P~
. -i 2. -.
0.0 2.5 3.0 3.5 4.0 41.5 50 3
Time (10 min)
Surry AG (HL LBLOCA)
CWDRDCQNK ~ 3/23/93 17:35:04 HELCOR IBM-RISC Figure 5.2.40 Distribution of Class 5 (Te) Chalcogen Radionuclides in Primary System, Containment and Environment.
I Predicted during AG Sequence, as Percentage of Initial Inventory in Com 69 NUREG/CR-6107.
u i
4 Results and Comparisons n
s=
Class 6 (Ru) 50 i
i i
i i
i i
i s
c Total Released m
g 45
- a
_ Primary c
- e - Containment
<r
__[
40
.-- a--
Environment o
35
- E_
30
' t mg
__-__a_____
O U
25 C
.2 b
20
- 5
+
.22 l
o 15 e
m
-_-a _._ -
_-a _ -.
=
13 g
10 y
Y E
5 ce
's 0
0 tiO' O tao' 0
2.5 3.0 3.5 4.0 4.5 5.0 3
Time (10 min)
Surry AG (HL LBLOCA)
CWDRDCONK 3/23/93 17:35:04 MELCOR IBM-RISC Figure 5.2.41 Distribution of Class 6 (Ru) Platinoid Radionuclides in Primary System. Containment and Environment Predicted during AG Sequence, as Percentage of initial Inventory in Core NUREG/CR-6107 70
I J
Results and Comparisons:
d i
Class 7. (Mo) 3.25 7
Total Released 3.00 g
- 0
. Primary 3
2.75
- -e - containment I 2.50
-- *-- Environment
_C t 2.25
,--w---.
2.00
/
we 6
" 1.75 1.
C
'e' l-
.1 1.50
-1
.c i
'C l
t; 1.25
,e 3
s-a I
1 00 p.
o 8.0.75 1
C
.9 a-o- - -o - - --o - ;
o 0.50 O
cr u
0.25 f-------*-------#-~~
II 0.00 0 tic' O t > c
d
2.5 3.0 3.5 4
0 45 l5. 0 j
3 Time (10 min)-
Surry. AG (HL LBLOCA)
JCWDRDCONK 3/23/93 17:35:04 MELCOR IBM-RISC Figure 5.2.42 Distribution of Class 7 (Mo) Early Transition Element Radionuclides in Primary System, Containment and 1-Environment Predicted during AG Squence, as Percentage ofInitialInventory in Core 71 NUREG/CR-6107.
- Results and Comparisons Class 8 (Ce) 2.25 i
i Total Released' m
{ 2.00
- o-Primary c
- e - Containment
.E 1.75
--A--
Environment E
f 3
1.50 m
<r
,.-o y
1.25
/y '
v
/
c 1.00 1
i a
6c-e-
- e
$ 0.75 h
O g 0. 5 0
___ p _ _ _ -
, F.__ __ g_
a 8
j 0.25
",-----*--------*------a f
0.00 0 t i c' tic' d
2.5 3.0 3.5 4.0 4.5 5.0 3
Time -(10 min)
Surry AG (HL LBLOCA)
CWDRDCONK 3/23/93 17:35:04 MELCOR IBM-RISC Figure 5.2.43 Distribution of Class 8 (Ce) Tetravalent Radionuclides in Primary System, Containment and Environment
~
Predicted during AG Sequence, as Percentage of Initial Inventory in Core NUREG/CR-6107 72
Results and Comparimms Class-9 (La) 22.5 i
i i
i i
7 Total Released m.
[ 20.0
- a-Primary T
-+- Containment 0"~~~~*~~~~
j
.5 17.5
--A--
Environment
~5E.s 15.0 et m
6 12.5 c
C 10.- 0 o
.-9u 35 7.5 o
?
5.0 g
I
.9
./
(
E 2.5 r_g ce NT# ~'V - @ ~7 ~-P -'
0.0
-A W
W
=
M w
w
- w y
2,5 3.0 3.5 4.0 4.5 5.0 Surry-AG (HL LBLOCA)
'CWDRDCQNK 3/23/93 17:35:04 MELCOR IBM-RISC Figure 5.2.44 Distribution of Class 9 (La) Trivalent Radionuclides in Primary System, Containtnent and Environment Predicted duing AG Sequence, as Percentage of Initial Inventory in Core 73 NUREG/CR4107.
Results and Comparisons Class 10 (U) 4.5 Total Released m
{
4.0
- D-Primary c
- e - Containment ~
v E
3'5
--A--
Environment Z
j
.2
[
'E 3.0 f
4
',_g-n.
'r 6
6 2.5 G
I c
f-e 2.0 a
- e 1.5 I
o l
3 e
1.0 aC l
.e q -e - - e- - - e-B 0.5 y-------+-------4------
e 4t 0.0 0 t t-c' O ti='
d
2.5 3.0 3.5 4.0 4.5 5.0 3
Time- (10 min)
Surry AG (HL LBLOCA)
CWDRDCONK 3/23/93 17:35:04 MELCOR IBM-RISC Figure 5.2.45 Distribution of Class 10 (U) Uranium Radionuclides in Primary System, Containment 1 avironment Predicted during AG Sequence, as Percentage of Initial Inventory in Core NUREG/CR-6107 74
a j
Results and Comparisons i
i
~i
- I Class 11 (Cd) 6.5 6.O
~
Totol Released j
_ Primary mxg 5.5
- e - containment
--A--
Environment 5.0
_C 2
4.5 y
c 4.0 we
--4~-~~*~~~T 3.5 A
CO5 3.0
(
.9 2*5 w
.-o 2.0
.o I
1.5 15~- - " ~~ -
T
~~
CO l
4,-----A------~+------
j 1.0 x
f 0.5 0.0 0 t1 O' O tic' 0
2.5 3.0 3.5 4.0 4.5 5.0 3
Time (10 min)
Surry AG. (HL LBLOCA)
CWDRDCQNK 3/23/93 17:35:04 MELCOR IBM-RISC l
Fig,re 5.2.46 Distribution of Class 11 (Cd) More Volatile Main Group Radionuclides in Primary System, Containment and Environment Predicted during AG Sequence, as Percentage of Initial Inventory in Core 75 NUREG/CR-6107
)
7 Results and Comparisons J
Class 12 (Sn) 7.0 6.5
~
Total Released
- D-Primary j
m>-
6*0 E5
- e - Containment f
8
5.5 --A--
Environment
>C i
5.0 oE 4'5
.5
, - e.
- - - o-
, 7
/
E 4.0 I
,8 3.5 7
-e 3
i
- e 3.0 A
2.5
' F 8
2.0
- =
O i r-4 --
E' E
1.5 O
I
-g o
1.0
,____+_______4_______,
e n
1 0.5 6
'l 0.0 0 t i c' 0 t 10 '
0
o 2.5 3.0 3.5 4.0 4.5 5.0 3
Time (10 min)-
Surry 'AG. (HL LBLOCA)
CWDRDCONK 3/23/93 17:35:04 MEL COR IBM-RISC Figure 5.2.47 Distribution of Class 12 (Sn) Less Volatile Main Group Radionuclides in Primary System, Containment and Environment Predicted during AG Sequence, as Percentage of Initial Inventory in Core NUREG/CR-6107 76
Results and Comparisons 450
=
Total Released
=
400
- o-Total in Pool /Atms
_ o_ _ _:
Aerosol in Pool /Atms -- E--
V0Por in Pool /Atms
/
350
--w-Total on HS I
/
g d5 300 o>
0 250 g _ _ _ _ _ _ _ _, _ _ _ _ _ _ _ y_ _ _ _:
13 IIj 3
i
~8 200
,i tt s
I )I C
150 i
- - - - a- - - - =
.g g
g 0
l l
)
100
/
4
/
50
!,b,_._._._._.y _._._._._._
0
=': 0 1
- 2. ='
0 1 2. U '
2.5 3.0 3.5 4.0 4.5 5.0 3
Time (10 min)'
.Surry AG (HL LBLOCA)
CWDRDCONK 3/23/93 17:35:04
.MELCOR IBM-RISC Figure 5.2.48 Total Fission Product Mass Released, and Overall Th Ei% tion, P--dicted during AG Sequence 77 NUREG/CR-6107
Results and Comparisons Table 5.3.1 Sequence of Events Predicted during S2D Sequence, Compared to STCP Key Event Tune (mia)
STCP MElf0R Accident initiation 0.0 0.0 Containment coolers on 1.0 0.3 Start steam generator depresuriution 30 5 30 5 Initial core uncovery begina 41.3 35.6 38.8 - 68.6 I"' N**)
Accumulators deliver until depleted 44.0 - 65.0 158.0 158.3 (Second Flow)
End steam generator deperasurization 60.0" 68.6 Gap relesse, Rirg 1 46.5 Gap release, Ri 42 48.1 llegin zitteley oxidation 61,7 Second core uncove y begina 114.7 101.9 Gap release, Ring-3 135.7 Primary system PORVs open 148.0 49.0 Core melt stana 161.6 130.0 Core slump 176.8 140.0 146.7 Core collapse 180.6 (Partial)
Ring-l Containment coolers trip off 267.0 Containment injection spreys on 188.0 267.0 U"* * " '
C'"' P'IO' I Bonom head dryout 209.2 failure of bottom head.
RWST depleted 363.6 l
Containment injection sprays oft 363.6 containment recirculation sprays on 282.4 272.0 l
1 148 3 1
Ikcom head failure 314.4 (Partial)
Ring-l j
Commence debris ejection 164.4 Begin concrete attack 315.5 227.6 1
1 1
Corium layers inven 372.5 333.3 End of calculation 915.5 833 4 NUREGICR4107 7g i
Results and Comparisons-20 a
Upper Head I8
~
0 Downcomer
- Co're
^
16
~
STCP me 14
u, n
o 12 cr m
2 l
2g 10.c 8
-i x
L o
E 4
c 6
a_
t i
4
- ~
2
- ^ '"
0
' ^ '
' ' " " ^ "
^~'
^
'^ ~
^
0 150 300 450 600 750 h
Time (min)
Surry S2D (HL SBLOCA)
DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC Figure 5.3.1 Primary System Pressures Predicted during S2D Sequence 79 NUREG/CR-6107
L.
Resuhs and Comparisons i
i i
i i
i i
1.4 C
Downcomer I*5 c
Upper Plenum
~
1.2 o
g
[
1.1 u
o O
1.0 o
E o
g i
g 0.9 g
e 0.8 3
o y
$WP 0.7
.9 y
0 E
o
'c 0.6 ll n.
0.5 fC-0.4 0.3 O
150 300 450 600 750 Time (min)
Surry S2D (HL SBLOCA)
DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC Figure 5.3.2 Primary System Temperatures, in Downcomer and in Upper Plenum Predicted during S2D Sequence NUREO/CR-6107 80
l Results and Comparisons 2.4 e
i i
e iiiiiiiiiiii
=
Upper Plenum.
g 1
2.2 l
- o-Top Core Level (Ring 1) l
- -a - Top Core Level (Ring 2) g 2.0
-- E-
. Top Core Level (Ring 3)
L "o
t G
I '# !
1.8 l
a si l
I8 g
1.6 g:,l E.
I kll l l E
1.4
{
lAl r
4 1
Ag 1.2 t,
in ll 3
1.0 i
\\
l Q
rI '
'xD 0
[
~ '$
0.8
~4 ~ -
'~~
~
V
=
=
0.4 0
150 300 450 600
.750 Time.(min)
Surry: S2D (HL SBLOCA)
DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC Figure 5.3.3 Core Exit Gas Temperatures, in Upper Plenum and in Uppermost Core Cells, Predicted during S2D Sequence 81 NUREG/CR-6107
1 l
Results and Comparisons i
16
-- e-- Lower Plenum -(Swollen)
=
Lower Plenum-(Collapsed) j4
--e-- Core (Swollen)
Core (Collapsed) 12
--A--
Upper Plenum (Swollen)
Upper Plenum (Collapsed) i m
E 10. c v
m5
-l I
8 F
4 1
~
j
.g.,;....... : :................ _
,E 6
~~~A, 4 -
b *, y-i i
.l
- .g-g 7...
2 i
H 1
I 0
0 40 80 120 160
- 200.
Time (min)
Surry'.S2D (HL SBLOCA)
DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC Figure 5.3.4 Reactor Vessel Liquid Levels Predicted during S2D Sequence NUREG/CR-6107 82
Results and Comparisons 160 i.
140 -
n u"
120 m
9 v
e 100 hy o
o 80 -
x0 E
i m
60 -
E" o
e_______.o________3_______e________
o 40 x
i
/
20 i
o i
i 0
0
'6
'c' c'
5 - '
'c' 0
150 300 450 600 750 h
O Pool (Break)
Time (min)
.Surry. S2D (HL SBLOCA)
-- e-- Ee m (Break)
" o H2 (Break)
DEDRANCNM 4/05/93-17:05:43 MELCOR IBM-RIS Figure 5.3.5 Integrated Outflows of Liquid, Steam and Hydrogen through the 11ot Leg Break Predicted during S2D Sequence 83 NUREG/CR4107
Results and Comparisons i
50 s
a n
45-1 1 40 9x "o
35 c
m*
30 il Oc3o 25 E
8 20 As j
15 o
II 10 5
, - - -s - - - - - -.e- - - - - - - -e - - - - - - - e- - - - -
i t
0 i ='
d
'c '
'c'
-d e'
O 150 300 450 600-750 Pool Time (min)
'.Surry S2D (HL SBLOCA)
-- e--
Steam DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC
" "D * " H2 m mmmmmmmmmmmmmme Figure 5.3.6 Integrated Outflows of Liquid, Steam and Hydrogen through the Vessel Breach Predicted during S2D Sequence l
NUREG/CR-6107 g4 i
Results and Comparisons
{
l i
.ii 2.50
=
Node 104 2.25 Node 105 1
- Node 106 '
i 2.00 I /
Node 107 2
Node 108 1.75 g
1 C
Node - 109 v
m.
l 0
Node 110' g
1.50
=
a Node.111 o
Node 112
{1.25 q
Node 113 E
e 6-1.00 h
l tw
.E E 0.75 0
l
\\:
l4 2
u M L 0.50
. o 0.25 0.00 0
50 100 150 200 250 l
h Time (m. )
i in Surry S2D (HL SBLOCA) i DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC Figure 5.3.7 Core Ring 1 Clad Temperatures Predicted during S2D Sequence 85 NUREG/CR-6107
Results and Comparisons t
I i
2.50 i
i
=
Node 204 2.25 0
Node 205-1 Node 206 2.00 Node 207-
/
^#
Node 208 1.75 o
Node 209 c
N de 210-E 1.50 H
,6 g
i Node 211 E
I Z - Node 212
/
e 1.25 Q-Node 213.
E e
H 1.00 p
._-E 0.75 S
- )
0-j t
H s.<.
m >
0.50 0.25 0.00 0
50 100 150 200 250 h
Time (min)
J Surry S2D (HL SBLOCA)
- DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC i
Figure 5.3,8 Core Ring 2 Clad Temperatures Predicted during S2D Sequence j
i NUREG/CR-6107 86 1
1
i Results and Comparisons i
I 2.50
=
Node 304 2.25 Node 305 1
Node 306
=i 2.00 Node 307
/
2
' Node 308 "g
1.75 C
Node 309 l
v O
Node 310 e
1.50 A
Node 311
- s
/
l Y
Node 312 i
g'
{ 1.25
.i:
Node 313 E
e 1.00 E
a l
$ 0.75 q
a R
r O-
<r.
0.50
' d. e-M l.
l 0.25 -
s 0
0.00-0 50 100 150-200 250-Time (min)
Surry S2D (HL SBLOCA)
-DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC Figure 5.3.9 Core Ring 3 Clad Temperatures Predicted during S2D Sequence 87 NUREO/CR-6107 i
i
f Results and Comparisons t
90
=
UO2 q
- e-Ziracioy I
80
-- E-- Zire Oxide H
-,6 - steel 70
- - v- - Steel Oxide m
o>
x
- -+- - C RP g
60 G
u>g 50 8
l JE gg 40 g
-o
---4 30 I
o l
8 1
o 20
___ 3 10 i s _ & _ __ _ _ w _ _ _.4 __._ _ __
- _ _. -
0 TE 5
- ;' 0; ': C TO' : '; - ' : 0 - f ; ' "
0 150 300 450 600 750 h
T.ime (min Surry S2D (HL SBLOCA)
DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC Figure 5.3.10 Core Total Material Masses Predicted during S2D Sequence NUREG/CR4107 gg
Results and Comparisons t-ty i
10
-^
i-igiqi i
i i
i i
i i
i i
l UO2 g -~ I g
0.9 l
- o-ziracioy
\\l L
-- E-- Zire Oxide g
0.8 o_ _ _
- + - st..i O
- - v- - Steel 0xide E
0.7
- -+- - CRP CD 1 1
.E 0.6 l
Eo" 0.5 i-g o
n 8
0.4 H
1
~dc 0.3
.2
_o j
0.2 I
0.1 Yl l e
- q........._+.._..._._._ +..._._.... _._..._..
7 r"- 6Il-
'='
d t
' = '
0.0 0
150 300 450 600 750 j.
Time (min Surry S2D (HL SBLOCA)
-DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC Figure 5.3.11 Core Fractional Material Masses Predicted during S2D Sequence 89 NUREG/CR-6107
(_:_
Results and Comparisons 55.
i
,g Ring.1 ' (COR.101) 50 it Ring 2 (COR.201)--
Ring 3 l(COR.301) 45 9?
40 e
v 35 n
8n_j 30
)
c8 25 n
'5 20
)
,eo e
15 Oo Si) 1
~
n 5
0 t ='
"- i ;
= ;;
si i;
0-150 300 450 600 750 h
T.ime (min)
Surry' S2D (HL SBLOCA)
DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC Figure 5.3.12 lower Plenum Debris Bed Masses Predicted during S2D Sequence NUREG/CR4107 90 a
~
Results and Comparisons p
2.25
=
Ring 1 (COR.101)
Ring. 2 (COR.201) i.
2.00
=
^
Ring 3 (COR.301) i 1.75 G
l i
L n
8 1.50
/
I o
k 1.25 E
>l l g
m 1.00 J
E 4
w
- 5 0.75 w
E L
E'O.50 Oo 0.25
^'
^^'
0.00 O
150 300 450 600 750.
Time (min)
Surry. S2D (HL SBLOCA)
DEDRAMCNM 4/05/93 17:05:43 MELCOR IBM-RISC
.gure 5.3.13 Lower Plenum Debris Bed Temperatures Predicted during S2D Sequence 91 NUREG/CR4107
]
Results and Comparisons 240 i
i i
i.
O Basement 220 i
cavity SG Cubicles -
Przr Cubicle
^
200 mg Dome
. 'a
......... STCP oc 180
~
i nr m
8 l.
g 160 a
m E
- t a
140 I
1 y
j o
i t D
E i
1 0
.E 120 a
O E
ip O
100 1
o 80 '*
x 60 O
150 300 450 600 750 Time (min)
Surry S2D (HL SBLOCA).
DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC Figure 5.3.14 Containment System Pressures Predicted during S2D Sequence
.NUREG/CR-6107 92
Results and Comparisons-1.3 O
Basement 12 Cavity.
~
x SG Cubicles-
"o I*I Przr Cubicle
^
Dome 1.0 sicP e
i j
' r g
0.9 i
n.
E 0.8 o
m Ey 0.7 a
e g
0.6 n
.c -
c 0.5 n
Oo-(
G'
=
g'= ' _ '
'.... :..s" '
.g.... :.'=............
0.4 0.3 0
150 300 450 600 750 Time (min)
Surry S2D (HL SBLOCA)
DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC Figure 5.3.15 Containment System Atmosphere Temperatures Predicted during S2D Sequence 93 NUREGICR-6107-
l Results and Comparisons
.1. 0 y ;,s,.,,
u,i i
l
-- m--
Steam lo i l
0.9 IllI i
- e - -N2 I
u
- a - 02 i
lu 0.8 i
~
t H2 -~
i i,
i s
-. _ e.. - C 0 i
07 n
s i
i si
- - e. - CO2 c
l' g[}IT i 1 ih
._9 ll
\\
.6-CH4 l
3 g
0.6 i
i d 's I
i e
0.5 h
E 5
1
, a..!- - - - - u - - - - - - -, _ _ _ _
1 b
0.4 l
M f-
'E l
,j %
i ! '\\
j o
l k'
0.3
, ~1 ij oA'_g.-*
q a
0.2 e'
I 3
,q
[j
.s.-.-.
._._..g_,,
^
u i
, t 0.1
+'
l:
I l
4 1
i-
?: 1l 2 t 3'M*DT - - '- ' *.-- - r- - r - e g
- e--
- - e - -
l 0.O c'
b 0
150 300
-450 600 750 h
1 i'
Time (min)
Surry S2D (HL SBLOCA)
J DEDRANCNM 4/05/93 17:05:43 MELCOR ' IBM-RISC
'l 1
Figure 5.3.16 Cavity Steam and Noncondensable Mole Fractions Predicted during S2D Sequence j
NUREG/CR-6107 94 e
Results and Comparisons 1
I I
I I
I I
I I
I I
I I
I i
1.
'o 7
-- m--
Steam -
x a
- e-N2 g 02 AD "i 6
L gi H2 g
j I
L
- -D- - CO o
o
\\
o
,- 'a g\\
- -e- -~ CO2 ng a
5
+
y ' 'i s
t 1,
b-CH4 I
I s
s e
T>
.\\,eA 4
A
' ~~ *
--A
,/
E 4
3 gy e
i g
,._.u- - - - - - - - M - - - - - - - -u li j
E 8
s S
h
'M l'
/
~
' if,,8
)
g 3 i e
i -
i E
L i i ii
.E l
I o
I r
n E
2 s
o 1 1 o
\\.
/
l7 1
pa :'~,,o, __. _..a- - w. _ m m.=.D.
.)
3 _ _ = _ _ _ e _ __
0 O
6: EC '
'O ' lh i'
E.
'A 0
150 300 450 600 750
.I Time (min)
Surry S2D (HL SBLOCA)
DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC 1
Figure 5.3.17 Containment Dome Steam and Noncondensable Mole Fractions Predicted during S2D Sequence 95 NUREG/CR-6107
.Results and Comparisons 160 o
Total
--- in core 140
'II in Cavity o
-- E-- on Structures 120 in Atmosphere
- - v- - in Pool V
100it o
1Ei3 80 x
g l e g
60 40 0
_ _ _,, _ _ =,,, _ _
_=_ __ __
0 0 *- ^= *' ' T T" "-9 ~ 7"' ""Z "t*'"*" "r ' O O
150 300 450 600 750
)
Time (min)
Surry S2D (HL SBLOCA)
DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC Figure 5.3.18 Decay Heat Predicted during S2D Sequence
. NUREGICR-6107 96
i Results and Comparisons i
l 200
- m-Total added by COR 180 0
Total in CAV
~~
-- A--
Gas released in CAV 160
- -H - Concrete oblated in CAV 140 m
o>
_ML
- m- - - m- - -s - - -
120 i
-v y>
o eg 100 Os x
80 G
ll 0
60 a
, _ - :n
- 4 40 0
F' I
20 i n I
0
': d d 'i " ' 'T'~'~~~~~'
~~I~~'~~~~'~~~'
~~
^
0 150 300 450 600 750 Surry S2D (HL SBLOCA)
DEDRANCNM 4/05/93-17:05:43 MELCOR IBM-RISC l
l l
Figure 5.3.19 Total Cavity Masses in Cavity Predicted during S2D Sequence i
l.
97 NUREG/CR-6107 l
l l
Results and Comparisons 160 O
H0X 1-e i
LOX 140
~
MET 3
a 120 E
v
.y 100 s
is y
80 a
.O j
60 o
.t>
40 0
3 20 o
r
' ^ '
'H 0
0 150 300 450 600-750-g Time (min).
.Surry S2D'(HL SBLOCA)
DEDRANCNM 4/05/93
'17:05:43
'MELCOR IBM-RISC 1
'l Figure 5.3.20 Cavity Layer Masses Predicted during S2D Sequence NUREG/CR-6107 98
.3 _
Results and Comparisons.
2.50.
i i
i i
i i
i i
i i
0 H0X-
-W 2.25 1
tox 2
MET Z
% 2.00 r
O 1.75 g
u 8.1.50
,,1 E4 1.25 f
.h 8
1.00
.E!
' 7 0 u
S 0.75
, )
o x
5 0.50 0
9 0.25 E'
'O d
'0' 0.00 t 0' 1
0 150 300 450-600 750 Time (min)
Surry S2D-(HL SBLOCA) o DEDRANCNM 4/05/93
.17:05:43 MELCOR IBM-RISC Figure 5.3.21 Cavity Layer Temperatures Predicted during S2D Sequence 99 NUREG/CR4107
Results and Comparisons 90 i
i i
i i
i i
i i
.g G
Decay-Heat 80 0
Chemical Reactions 70 60 M3 50 m
8 40 a
S 30 0
3 20
, 3 F_
c k
10
~
o 0
0 0
0 0
0 0
-10
-20
-30 O
150 300 450 600 750 Time (min)-
Surry S2D (HL SBLOCA)
-DEDRANCNM 4/05/93.
17:05:43 MELCOR IBM-RISC Figure 5.3.22 Decay Heat and Chemical Energy in Cavity Predicted during S2D Sequence NUREO/CR-6107 100
~..
\\
Results and Comparisons Cavity Minimum Depth.
1.4
' I'. 3 m
E 1.2 v
f 1.1 1.0 Cavity Maximum Radius 4.50
[
~
4.45 4.40 J
nE'
-v n
-j 4.35 4.30 4.25 0
150 300 450 600 750.
Time (min)
SurrylS2De(HL SBLOCA)
DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC Figure 5.3.23 Cavity Maximum Radius and Minimum Depth Predicted during S2D Smuence 101
Results and Comparisons i
e i
i i
i e
i e
i i
i e
i i
7 6
, E'
/*%m
.x n
X 8
5 r
s' 8
i g
4 Total from Cavity
]
/
- e-H2 from Cavity i
v>
H2O from Cavity
< o i
o 3
--r-- C0 from Cavity o
- -+- - 'CO2 from Covity g H2 from Core o
2 s
--E--
CO from Core
- -o- - CO2 from Core 1
u
--+-- CH4 from Core '
0
. i -- - m_m. --s _w e-is i hm.__ _5E ea r-h w.
- e-0' 150 300 450 600 750 t
l Time (min) i Surry S2D (HL SBLOCA)
DEDRANCNM 4/05/93 17:05:43
'MELCOR IBM-RISC I'
Figure 5.3.24 Gas Generation Predicted in Core and in Cavity during S2D Sequence l
NUREG/CR-6107 102 l
l-
i Results and Comparisons Table 5.3.2 Radionuclide Distribution at 833 min for S2D Sequence Radionuclide Species Group and Core RCS Cavity Containment Representative Element Noble Gases, Xe 3.06E-04 3.34E-03 0
0.9 %
Alkali Metals, Cs 2.94E-04 0.139 2.54E-18 0.860 Alkaline Earths, Ba 4.63E-04 7.56E 03 0.703 0.289 Halogens, I 6.04E-04 1.99E-03 0
0.997 Chalcogens, Te 4.67E-04 8.97E-03 0.685 0.306 Platinoids, Ru 4.68E-04 2.12E-04 0.999 7.45E-04 Transition Metals, Mo 4.63E-04 5.13E-03 0.974 1.99E-02 Tetravalents, Ce 4.68E-04 5.59E-06 1.0 2.07E-05 Trivalents, La 4.68E44 5.52E-05 0.997 2.79E-03 Uranium, U 7.04E44 5.08E-05 0.999 2.48E-04 6E@
2.93E42 0.873 9.78E@.
i Gr u Metals, Cd
!iin!TZ"*Meais, Sn 4 s68-o4 2.93E-02 0.86, 0.iO9 i
s l
103 NUREG/CR-6107 i
I Results and Comp; isons i
Class 1 (Xe) 100
,c,
,=,
9 90 8
80 j
n
-70
.~_O.
_5 60 H:
50
= i ~& - -- --v 5 -
-2.g -
7 =I E
u_
,r 40 Eo o
I 30 g
y I
8 1
_E 20 7
I e
a::
O l
10 0
e T' d' 0
150 300 450 600 750 Time (min)
- v-Primary g
Surry S2D (HL SBLOCA)
- a - Cavity DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC c
Total t
Figure 5.3.25 Release of Class I (Xe) Noble Gas Radionuclides from Fuel in Core and in Cavity Predicted during S2D Sequence, as Percentage of Initial Inventory in Core l
l NUREG/CR-6107 104
~'?
i l
l Results and Comparisons 1
-1
' Ciass 2- (Cs) 110 O
a c
c I
-100 nb 90
.8c n
s' 80
. _C D
70
- =
.5 -
g 60 v
1 l
g _ __+_ _. 4 __ __ __ __ & __ _ _.
8 50
-9 w.
I I
5 40 t-1 r
l 7
30 w
I 0
i 20
, 7 m
/
n g
10 a
f
/
11 0
t v' 0
150 300 450 600 750 o
T.ime (min)
- v-Primary-r Surry -S2D (HL SBLOCA)
- +
cany l'-DEDRANCNM 4/05/93 1'7:05:43 MELCOR IBM-RISC i
Figure 5.3.26 Release of Class 2 (Cs) Alkali Metal Radionuclides from Fuel in Core and in Cavity Predicted during S2D l
Sequence, as Percentage of Initial Inventory in Core 105 NUREG/CR-6107
..t i,
Results and Comparisons 1
Class 3 (Ba) 30.0 tb 27.5 w---s----s--
p 25.0 f
O 3 22.5
^
g II Z 20.0
.e
-3 17.5 11
. L 15.0 l
I 12.5-Ip E
10.0 o
4 8
7.5 1
g i
3 5.0 I
/
R 7 l'- * - - " - - ' - -
2.5
/
0.0 t v' h
0 150 300 450 600 750 Time (min)
- v-Primary Surry S2D.(HL SBLOCA) Cavity DEDRANCNM 4/05/93
.17:05:43 MELCOR IBM-RIS'C o
Total Figure 5.3.27 Release of Class 3 (Ba) Alkaline Earth Radionuclides from Fuel in Core and in Cavity during S2D Sequence, as Percentage of initial Inventory in Core NUREG/CR-6107 106
Results and Comparisons i-r Class 4 '(1) 55 7
0 7
0 7
0 C
50 mb 45 o
'r C
i 40
.s 3
35 U
- =
_C 30 a
v 8
25 w
r 5
20 g
n 1
15 8
10 m
F n
5 O
t 7'
'l
'a
'i' i'
i 0
150 300 450 600 750 i
Time (min)
- v-Primary. cavity Surry S2D (HL SBLOCA)
DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC Tow 1
i Figure 5.3.28 Release of Class 4 (1) Halogen Radionuclides from Fuel in Core and in Cavity Predicted during S2D Sequence.
I as Percentage of laitial Inventory in Core
-l 107 NUREG/CR-6107 -
)
l1
' Results and Comparisons;
- C) i d
W
'l:{
Class 5 (Te) 32.5 m
~
30.0
,e_4-*-
{
27.5 t
25.0 e
L
.]
I 5 22.5
~5 tb IE 20.0 s
a 17.5 a
v
~
15.0 S
u.
E 12.5 rp 8
i 4
10.0 o
L O
I 8
7.5
'l
--O e
5.0 I
L g:
-f v- - - v--
-v-2.5 d
A O.0 0
150 300 450 600 750 i
Time (min) v
. Primary'.
Surry S2D (HL SBLOCA)
-- + - CmHy i
o Total DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC Figure 5.3.29 Release of Class 5 (Te) Chalcogen Radionuclides from Fuel in Core and in Cavity Predicted during S2D d
Sequence, as Percentage of Initial Inventory in Core NUREG/CR-6107 jog
~
q g...
p
-l d~
Results and Comparisons
-1 1
,.1 1
Class 6 (Ru) 1.0
,4 0.9-T o
0.8 ee>
C Z
0.7
.9 5
- 0. 6 -
.bt 9
0.5 n
w
.2 0.4 E
3 0.3 mo E
0.2 eT 7
u
.I 0.1 b
0.0 O
150 300 450 600 750
'l g
1 Time (min)
- v-Primory Surry S2D '(HL SBLOCA)
- + - cmHy q
C
- I DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC 1
Figure 5.3.30 Release of Class 6 (Ru) Platinoid Radionuclides from Fuel in Core and in Cavity Predicted during S2D Sequence, as Percentage of Initial Inventory in Core
.j 109 NUREG/CR-6107
3
-i Results and Comparisons Class 7 (Mo) 2.75 2.50
=
nt 2.25 OE E 2.00
_C
~5 1.75
=
.c.-
7 1.50 n
E 1.25 u.
5 1.00 r) k 2----&----s 3 0.75 m
/
E e
s 0.50
, 7 oc
/-
r) 0.25 I
0.00 t v' lh 0
150 300 450 600 750 Time (min)
- v-Primary Surry S2D (HL SBLOCA)
- + - cmHy DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC Total
)
Figure 5.3.31 Release of Class 7 (Mo) Early Transition Element Radionuclides from Fuel in Core and in Cavity Predicted l
during S2D Sequence, as Percentage of Initial Inventory in Core NUREG/CR4107 110 4
Results and Comparisons Class.8 (Ce) 2.75
= -
2.50
~
T L.,y 2.25
_y_
_g_
4 E 2.00
[
3:::
'r
_i_= 1.75 7
1.50 r) 52 v
1.25 8
u.
1.00 E
gj 8* 0.75 I
m 0.50
,,,,,__ __ e e
a-0.25 r) f
/
0.00 t'
k 0
150 300 450 600' 750 Time (min)
- v-Primary.
- cmuy.
Surry. S2D (HL SBLOCA)
C Total DEDRANCNM 4/05/93 17:05:43.
MELCOR IBM-RISC Figure 5.3.32 Release of Class 8 (Ce) Tetravaient Radionuclides from Fuel in Core and in Cavity Predicted during S2D Sequence, as Percentage of Initial Inventory in Core e
ill NUREG/CR-6107 R
Results arid Comparisons Class 9 (La) 3.00 i
i i
i i
i i
i c
C C
c 2.75
^
n
$2.50 r--*------*------*-
1:I 2.25 s
5 2.00 I
y 1.75 f
I I
l 9
1.50'
-e i
s 1.25 i l 5
1.00 I
L o 0.-75
'I 8
.E 0.50 i
e 9
- --"--~~#~-
0.25 4
'~#'
0.00 t 7' i
l 0
150 300 450 600 750 Time (min)
- v
. Primary Surry S2D (HL SBLOCA)
-- + -- Cavity -
DEDRANCNM 4/05/93 17:05:43 MELCOR 1BM-RISC l
Figure 5.3.33 Release of Class 9 (La) Trivalent Radionuclides from Fuel in Core and in Cavity Predicted during S2D Sequence, as Percentage of Initial Inventory in Core NUREG/CR-6107 112
Results and Comparisons Class 10 (U) 35 0
i i
i i
e i
i i
i_i i
i_,
i i
2
( _ _ h.__ _-
32.5 mb 30.0 2
5 27.5
--E 25.0
,y Oj 22.5 yt 20.0 l9 17.5 v
j 15.0 u.
12.5 E
o ir b
10.0 o
8 7.5 8s 5.0 ce 2.5 a- - - -- s.- -- - -- w -
0.0 i'
n 0
150 300 450 600 750 Time (min)
- v-Primaryc 6.-
. Cavity Surry S2D (HL SBLOCA) o Tofat DEORANCNM.4/05/93 17:05:43 MELCOR IBM-RISC Figure 5.3.34 Release of Class 10 (U) Uranium Radionuclides from Fuel in Core and in Cavity Predicted during S2D Sequence, as Percentage of Initial Inventory in Core 113 NUREG/CR-6107
Results and Comparisons Class 10 (U) 35.0 1
[ _ _ ~, _ __
32.5 mb 30.0 2
5 27.5 E
25.0 i)
OE 22.5 C
M 20.0 m
i E
17.5 v
T 15.0 of 12.5 Eo er 10.0 O
8 7.5 O
5.0 x
2.5 4_.
)
0.0 d'
f.
1 1
0 150 300 450 600 750 Time (min)
- v-Primary.
Surry S2D (HL SBLOCA)
- + - CaHy 3
i'I DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC summmmmmmmmmmmmmmma Figure 5.3.34 Release of Class 10 (U) Uranium Radionuclides from Fuel in Core and in Cavity Predicted during S2D Sequence, as Percentage of Initial Inventory in Core i
1 113 NUREG/CR-6107
~.
Results and Comparisons Class 11 (Cd) 13 p _
.__9_;
4:
12 i
g 1.1 bg 10
?
_c 9
35 8
E tr u
7 v
6
.t2 E
5 2
4 i
8 3
.e Oa:
2
' r 13 1
0 i'
' e " --' -- "* * - ' - + 4' - " " - 6 0
150 300 450 600 750 Time. (min)
- v-Primary Surry S2D (HL SBLOCA) 4-Cavity DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC o
Total Figure 5.3.35 Release of Class 11 (Cd) More Volatile ~ Main Group Radionuclides from Fuel in Core and in Cavity Predicted during S2D Sequence, as Percentage ofInitialInventory in Core NUREG/CR-6107 134
L, Results and Comparisons Class 12 (Sn) 14 i
i
=.
m 13
_y_
=
___,____y___
12 mb
)
S 11 c
i r
.g 10 y
9
=5 g
7 a
2 6
Eo 5
4:
m 4
8 8
3 e"
2
' r
_6_ _ _ _.4 - - - _ A- - _
u O
d 7' E
0 150 300 450 600 750 i
Time (min)
- v-Primary _ covHy Surry S2D (HL SBLOCA)
Total DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC wmmmmmmmmmmmmmmme Figure 5.3.36 Release of Class 12 (Sn) Less Volatile Mair. Group Radionuclides from Fuel in Core and in Cavity Predicted during S2D Sequence, as Percentage of Initial Inventory in Core 115 NUREO/CR-6107
0 Results and Comparisons ~
4 Class 1 (Xe) 100
,e 1 -
r m 90 mb o
c 80 o
N
_C 70 g
r
-l
'E 60 1
w
)
50 3
.-9 7
.h 40 a
l 25 9
.g 30 5
E 20 7
Total Released o
r 95 i j Primary o
i i 0:
- e - Containment 10
--A--
Environment ~
0 6 7 ' 1 "" b 'n '
b e
'c 0
150 300 450 600 750--
Time (min)
Surry S2D (HL SBLOCA)
DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC l
l l
Figure 5.3.37 Distribution of Class 1 (Xe) Noble Gas Radionuclides in Primary System, Containment and Environment Predicted during S2D Sequence, as Percentage ofInitial Inventory in Core NUREG/CR-6107 116 l
Results and Comparisons F
Class 2 (Cs) 110
[ v v
v v
100 Tu o
I
- ]
j 90
._ e._ _ _ _o_ _ _ - -o_ _ _
i 4
5 80 I
6_
I 9
j 70 7
Total Released I
M
- O-Primary
/
60
- e - Contoinment c
j
--A--
Environment
- i a
50
/
e P
2 r
y 40 o"
.3 30 t
8 I
C
.e 20 a
"g (1 7 -e ~ _
-e.
s.- _ _ o__
b L
10 f
l 0
i 7't "
'i'
'a
'a' 0
150 300 450 600 750 l
Time (min)
Surry S2D (HL SBLOCA)
DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC Figure 5.3.38 Distribution of Class 2 (Cs,) Alkali Metal Radionuclides in Primary System, Containment and Environment l
Predicted during S2D Sequence, as Percentage of Initial Inventory in Core 117 NUREG/CR-6107
Results and Comparisons Class 3 (Bo) 30.-0
, _ -- -o -.._ - -..e -- - -- -- e.
l 27.5 2j5 25.0 C*
Total Released
~
n 22.5
<r 0- Primary 0
-E 20.0 c
e ontainment
^5 A--
Environment x.17.5 v-1 5.'0
- a e
12 5
h
.e i
Q 10.0 eo Ti 7.5 2
C 5.0 D.
Q:
/
2.5 r:
e t
_. m 7 1.r T
ie.,
, - Eh_-
Q_,-
i.
0.0 0
150 300 450 600 750 Time (min)
Surry S2D (HL SBLOCA)
DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC
- Figure 5.3.39 Distribution of Class 3 (Ba) Alkaline Euth Radionuclides in Primary System, Containment and Environment during S2D Sequence, as Percentage of Initial Inventory in Core
.I NUREG/CR-6107 iig e
b Results and Comparisons Class 4 -(l) 55 0
0-4-
,I O
50 1
b
/
2 45 c
y E
I s
40 I
o
[c 35 d
M
)
30 C
.93 25 e
r b3 20 0
o e) i l i
32 15 5
i 7
Total Released 8g 10
- o-Primary j
cE
- e - Containment 5
--A--
Environment T
,N m,
. _,. o 0
0 150 300 450 600 750-1 Time (min)
Surry. S2D (HL SBLOCA)
DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC Figure 5.3.40 Distribution of Class 4 (1) Halogen Radionuclides in Primary System, Containment and Environment Predicted during S2D Sequence, as Percentage of Initial Inventory in Core 119 NUREG/CR-6107
'.]
Results and Comparisons Y
l Class 5 (Te) 32.5 30.0
.,_ _ - o. i s
g 27.5 e*
25.0 C
s 22.5
'r
- E-"
20.0 Total Released-o w
-D-Primary v
17.5
-c
- e - Containment-O 5
15.0
--A--
Environment e
r j
12.5 n
,o e
10.0 D
8 7.5 C
'Y O
- 6 5.0- -
/o 0
2.5
,e
' /
'T T N '~ '
' D T T D '~
~
0.0
^ -
0 150 300 450 600 750 Time (min)
Surry S2D (HL SBLOCA)
DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC Figure 5.3.41 Distribution of Class 5 (Te) Chalcogen Radionuclides in Primary System. Containment and Environment Predicted during S2D Sequence, as Percentage of InitialInventory in Core NUREG/CR-6107 120
j Results and Comparisons Class 6 (Ru) 1.0 3
0.9 s'
O.8 C
y 0.7 f.__e_____._o.____.e____e.__
E Q
Total Released M
0.6 I
i Primary o
I:
- e. - containment o
l 0.5 o
--A
- Environment g
l 2
0.4
.t:
o n
25 0.3
- 'l a>
I; 32 l
l 3
0.2
-- o --- -- _
-8
--- * - - F g
8 Ti 5
o 0.1 I
ce l
0.0 6
'1 "
'a' d
'a
'l' 0
150 300 450 600 750 Time (min)
Surry S2D (HL SBLOCA) i DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC -
Figure 5.3.42 Distribution of Class 6 (Ru) Platinoid Radionuclides in Primary System, Containment and Environment L
Predicted during S2D Sequence, as Percentage ofInitialInventory in Core 121 NUREG/CR-6107
l 1
R Results and Comparisons I
q J
l
.J l
1 1
Class 7 (Mo) l 2.75 2.50 7
7 Tu 1
2 2.25 C
+
@>5 2.00 i
e - - - - e- - - - --o -
r
.9
]
1.75 p'
E
/
Total-R6! eased 1.50 I
@ Primary
'5 1.25
- e - containment 3
d o
--A--
Environment
.2 1.00 5
-o O;8 0.75 8
.E 0.50 he
--El - - -e - -
B-D--
E v
a:
0.25 I
T 0.00 67'1"
'l' d
'e-
'i '
0 150 300 450 600-750 Time (min)
Surry S2D (HL SBLOCA)
DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC Figure 5.3.43 Distribution of Class 7 (Mo) Early Transition Element Radionuclides in Primary System, Containment and Environment Predicted during S2D Sequence, as Percentage ofInitial Inventory in Core l
NUREG/CR-6107 122
Results and Comparisons
)
I
-)
Class 8 (Ce) 2.-75 y 2.' 5 0 o
c g 2.25 c
$ 2.00
,o-e~~~"~
s
~~*i=
1.75
/
et e ' ~ ~ ~d Total Released
~
h 1.50 l - Primary I
- e - containment 1.25 3
--A--
Environment
.o I
E 1.00 P
.ao 0.75 U.
3' I
g 0.50
, ( a __..__ _e _.__
.e-e--
m O
Y 9
g 0.25 1
0.00 0
150 300 450 600 750 Time (min)
Surry S2D (HL SBLOCA)
DEDRANCNM 4/05/93
'17:05:43 MELCOR IBM-RISC i
Figure 5.3.44 Distribution of Class 8 (Ce) Tetravaient Radionuclides in Pamary System, Containment and Environment -
Predicted during S2D Sequence, as Percentage of Initial Inventory in Core 123 NUREG/CR-6107
' Results and Comparisons 1
Class 9 (La),
3.00
*----+----4--'-
i g 2.75 e
i I 2.50 e>
S-7 Total Released
,3.- Primary 3 2.00
- e - containment 3
--4--
Environment g
T 1.75 9
v 1.50 c
.2j 1.25 7
_c o
.E!
1.00 O
$ 0.75 6ag 0.50
?,0.25
/
F-m t~ ' - e, n m e ;-
-, m,,, -i- &, c 0.00 0
150 300 450 600 750 Time (min)
Surry S2D (HL SBLOCA)
DEORANCNM 4/05/93 17:05:43 MELCOR IBM-RISC 1
Figure 5.3.45 Distribution of Class 9 (La) Trivalent Radionuclides in Primary System, Containment and Environment Predicted during S2D Sequence, as Percentage ofInitial Inventory in Core
'I NUREG/CR-6107 124
Results and Comparisons -
Class 10 (U) 35,0
- 32.5
-@ 3 0. 0
.E 27.5
+~~~~4-------*--~~--
_w
/
y 25.0 C
22.5
~
I a
Total Released E
7 20.0
- D-Primary o
I C,
- e - Containment 17.5 I
g
--A--
Environment 5
15.0 ag 12.5 0
5 I I 10.0 e
i o
ll' 5
7.5 a
5 5.0
>---D---
-- -a --- --
-e_
g o
x 2.5 0.0 6'
P!
'l' d
0 150 300 450 600 750 Time (min)
Surry S2D (HL SBLOCA)
DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC Figure 5.3.46 Distribution of Class 10 (U) Uranium Radionuclides in Primary System. Containment and Environment Predicted during S2D Sequence, as Percentage of Initial Inventory in Core 125 NUREG/CR-6107 9
Results and Comparisons Class 11 (Cd) 13 7:
- v 12 T
f 11 o
't C
j 10
,,_ _ g
,_____e___.._
__e.__
____o___-
m 9
6
^E l
E 8
U If Total Released 7
9
_ Primary 5
6
- e - Containment
..o o
3
~~^~~
5
.22 b
o
-l e
4 2
d( + - - e- - - o-- - - o - - --
8 3
C Oj 2
IP x
1
)
0 0
150 300 450 600 750 Time (min)
Surry S2D (HL SBLOCA)
DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC Figure 5.3,47 Distribution of Class 11 (Cd) More Volatile Main Group Radionuclides in Primary System, Containment and.
Environment Predicted during S2D Sequence, as Percentage of Initial Inventory in Core NUREG/CR-6107 126
i Results and Comparisons Class 12- (Sn) 14
]
13 2
./
{
12 u
O l
e E
- l, j
t1 g
_ _ _ _ _ _ _ _ 4 _ _ __
l
?
G
}
i 10 g
,_ __ __ _c,
j 9
f
'l I
t w
8 l
Total Released v
'I 7 PrimaryL g
3
- e Containment e
6 i
j; a
--A--
Environment-i^
f 5
l i
4 P
o u
j 3
i
- -e - - e- _ _ _
e_.
I 2
I B e
l 1
0 i v'i d
'l'
.d
'A
'A 0
150 300 450 600 750 Time (min)
Surry S2D (HL SBLOCA)
DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC Figure 5.3.48 Distribution of Class 12 (Sn) Less Volatile Main Group Radionuclides in Primary System, Containment and Environment Predicted during S2D Sequence, as Percentage of Initial Inventory in Core 127 NUREG/CR-6107 l
-j
,)
Results and Comparisons p
1 500 450
__ _._ __ _.__ _ __. e_ -
400
=
Total Released I
9
- o-Total in Pool /Atms a
350
/
- -e - Aerosol in Pool /Atms v>
/
a>
-_ g--
Vapor in Pool /Atms n
300 o
- -* - Total on. HS t
2
[
h t
250 a
i T
0 I
./l e
200 3l c
m_____________.
/
l
]
150 m
-c
(
l 100
/
50 8 I~~
l,.
y_._ _._......_..._ _._._._._..
+
0
'a A O
150 300 450 600 750 Time (min)
Surry S2D (HL SBLOCA)
DEDRANCNM 4/05/93 17:05:43 MELCOR IBM-RISC i
Figure 5.3,49 Total Fission Product Mass Released, and Overall Distribution, Predicted during S2D Sequence
]
i NUREG/CR-6107 128
Results and Comparisons Table 5.4.1 Sequence of Events Predicted during S3D Sequence, Compared to STCP Key Event Time (min)
STCP MELCOR Accident ini6ation 0.0 0.0 Containment coolers on 1.0 0.4 Start steam generator depressuri7ation 30.0*
30.0*
38.8 - 113.3 Accumulators deliver until depleted 40.0 - 80.5 656 - 0.0 -
(Second Flow End steam generator depressurization 60.0*
110.1 Initial core uncovery begins 525.4 590.6.
Gap release, Ring-1 606.2 Gap release, Ring-2 608.6 Gap release, Ring-3 617.3 Primary system PORVs open 658.0 616.7 Begin zircaloy oxidation 620.1 Core melt starts 687.3 625.0 Core slump 707.9 630.0 739.0 Core collapse 716.7 (Partial)
Ring-2 Containment injection sprays on 850.9 Containment recirculation sprays on 855.1 I
Does not occur prior to Bottom head dryout 740.6 failure of bottom head 739.9 Bottom head failure 849.1 (Partial)
Ring-2 Commence debris ejection 739.9 l
Begin concrete attack 850.1 740.0 Corium layers invert 921.1 900.0 RWST depleted 944.4 Containment injection sprays off 944.4 End of calculation 1,450.1 1,666.8 129 NUREG/CR-6107
~ Results and Comparisons-20 i
i i
i i
i i
c Upper Head 18
~
0 Downcomer i
Core H
16
......... STCP
-o 14 a.
[]
m 9",
12 6 ye t
u 3
g 10 a 3
3 8
i xu t o o
E 13 c
6 q
a_
4 4
.................. ii 2
y c. :a z, -
2
~^
~^
0 O.0 0.4 0.8 1.2 1.6 i
3 Time (10 min)
Surry S3D (Pump Seal Leakage SBLOCA)
CPDPEGDNI 3 / 16 / 9 3 15:4 8:10 MELCOR IBM-RISC 1
i i
.i Figure 5.4.1 Primary System Pressures Predicted during S3D Sequence
)
i NUREGICR-6107 130 i
p Results and Comparisons
- 1. 6.
i.
i q
Domomer -
1.5 Upper Plenum 0
1.4 o
(
p 1.3 n8 1.2 d
c 3
o
[
E 1.1 o
0 b
1.0
' )
i n.
t E*
l' 0.9 o ci 0
b 0.8
'o
.E E
0.7 U
8 g
0.6 d
0.5 p
.. - - =. s.. :
0.4 0.0 0.4-0.8
- 1. 2 -
1.6 3
Time (10 min)
Surry S3D (Pump Seal Leakage SBLOCA)_
CPDPEGDNJ 3 /16 / 9 3 15:4 8:10 MELCOR IBM-RISC Figure 5.4.2 Primary System Temperatures. in Downcomer and in Upper Plenum, Predicted during S3D Sequence 131 NUREO/CR-6107
4 M
Results and Comparisons 2.75
=
Upper Plenum 2.50
('
- o-Top core Level (Ring.1) 4 X
- e - Top Core Level (Ring 2)
~
g 2.25 "o
,; t
--E--
Top Core Level (Ring.3)
I
" 2.00 8
q L bi l
g 1.75 t
b l
o-I g
1.50 f
j w
o r x, 8
1.25 M
"$b o
f
],
y.-r-d 1.00 l
t 0 0.75 l l
.0.50 ii O.25 O.0 0.4 0.8 1.2 1.6 3
Time (10 min)
Surry S3D (Pump Seal Leakage SBLOCA)-
CPDPEGDNJ 3 / 16 / 9 3 15:4 8:10 -
MELCOR IBM-RISC Figure 5.4.3 Core Exit Gas Temperatures, in Upper Plenum and in Uppermost Core Cells Predicted during S3D Sequence NUREG/CR4107 132 l
- d
'j l
Results and Comparisons -
j 1
)
-)
i 16 i
i
--E--
Lower Plenum- (Swollen)..
=
Lower Plenum (Collapsed) j4
--e--
Core (Swollen)
Core.(Collapsed) 12
--*-- Upper Plenum '(Swollen)
Upper Plenum (Collapsed) n E
10 v
2 h
8
~#
~
~ 25 1 L r ' T. -
.................................... 1
~$'Y " ~6
~
6 t
W =L4, 4
. o
. c
=
=
=-
=
g An.
2 0
- f C 0
100 200 300 400 500 600 700-800-g Time (min)
Surry S3D (Pump Seal Leakage SBLOCA)
CPDPEGDNJ 3 /16 / 9 3 15:4 8:10 MELCOR IBM-RISC Figure 5.4.4 Reactor Vessel L.iquid Levels Predicted during S3D Sequence 133 NUREG/CR-6107 i
Results and Comparisons i
250
=
=
I.
225 l
200 l
e l
175 n
o i
5 150 1
o O
g 125
$3 100 1
B l
75 l
ct Ea 50 i
n.
25 0
0 0
'O
" * ~ ~ T ~ ~ ~ * ~ ~5 " - -e r y r -
0.0 0.4 0.8 1.2 1.6 3
Pool Time (10 min)
~ ~ * ~ ~ SI ' *
-Surry S3D (Pump Seal Leakage SBLOCA)
" " * * " H2 CPDPEGDNJ 3 /16 / 9 3 15:4 8:10 MELCOR IBM-RISC Figure 5.4.5 Integrated Outflows of Liquid, Steam and Hydrogen through the Hot Leg Break Predicted during S3D Sequence NUREG/CR-6107 334
-4 Results and Comparisons i
i 1
14 13 12 11
_x 10 m
E 9
m*
_o_
8
=ao 7
.c 8
6 co 5
E 4
n O>
3 2
1
, -,.o- - - - - - - - s - - - - - - - U- -
0 0 ='
O
'O=
O 6
-C'-
A d"-
0.0 0.4 0.8 1.2 1.6 3
Pool Time (10 min)
Surry S3D (Pump Seal Leakage SBLOCA)
-- e--
Steam CPDPEGDNJ 3 /16 / 9 3 15:4 8:10 MELCOR IBM-RISC Figure 5.4.6 Integrated Outflows of Liquid, Steam and Hydrogen through the Vessel Breach Predicted during S3D Sequence 135 NUREG/CR4107
J Results and Comparisons P
2.50
=
Node 104 2.25 Node 105 1
Node 106 2.00 Node 107 2
Node 108 i
"g 1.75 0
Node 109
~
[ 1.50 0
Node 110 g
a Node III
~
z O
2 Node 112 g' 1.25 Node 113-
~
E0 i >
1.00
._E' E 0.75 i
0 0.50
- n~Ib
]
0.25 0.00 0
100 200 300 400 500 600 700 800 Thie (min)
Surry. S3D (Pump Seal Leakage SBLOCA)
CPDPEGDNJ 3 /16 / 9 3-15:4 8:10 MELCOR IBM-RISC Figure 5.4.7 Core Ring i Clad Temperatures Predicted during S3D Sequence NUREG/CR-6107 136
4 4
Results and Comparisons 2.50
=
Node 204 2.25 Node 205 1
Node 206 f
2.00-Node 207 2
Node 208 a
1.75 0
Node 209 g
yi O
Node 210 g
1.50 1
Node 211 1
2 Node 212
[ 1.25 Node 213
,,1 1
l Eo 1.00
.E_.
0.75 O
}
=_
_crs O.50 0.25 0.00 0
100 200-300 4~00 500 600 700'
~800 i
Time (min)'
1 Surry S3D '(Pump ' Seal Leakage SBLOCA)
CPDPEGDNJ 3 /16 / 9 3 15:4 8:10 MELCOR JBM-RISC Figure 5.4.8 Core Ring 2 Clad Temperatures Predicted during S3D Sequence 137 NUREG/CR-6107
i Results and Comparisons -
i i
i 2.50
=
Node 204 2.25 Node 205 Node 206 h
2.00 Node 207 2
Node 208 a
1.75 0
Node 209 g
/g -
v O
Node 210 g
1.50 e.
Node 211 Node 212 o{1.25 l i Node 213 g
E e
1.00
.E_"
E 0.75 0
rw N
)
0.50
-- =
O.25
^' "' -
~
0.00 0
100 200 300 400 500 600 700 800 Time (min)
Surry S3D (Pump Seal Leakage-SBLOCA)
CPDPEGONJ 3 /16 / 9 3 15:4 8:10 MELCOR IBM-RISC Figure 5.4.8 Core Ring 2 Clad Temperatures Predicted during S3D Sequence 137 NUREG/CR-6107
Results and Comparisons 2.50 i
=
Node 304 l
2.25
. Node 305 i
Node 306 l
i Node 307 f
2.00 2
Node 308 "g
1.75 C
Node 309 v
O Node 310 e
1.50
-a Node 311 a
o Node 312 f
{1.25 Node 313 l l 1.00 i
.E._
E 0.75 2
. - - : u --
2 ;w n,
_. - AG 0.50 0.25 0.00
- ' ::J::
i 0
100 200 300 400-500 600 7.00 800 Time (rnin)
J Surry S3D (Pump-Seal Leakage SBLOCA)
CPDPEGDNJ 3 /16 / 9 3-15:4 8:10 MELCOR IBM-RISC Figure 5.4.9 Core Ring 3 Clad Temperatures Predicted during S3D Sequence NUREG/CR-6107 138
Results and Comparisons 90
=
UO2
~
80
- e-21roctoy
-- E-- Zirc 0xide
- -a -- st el f
70
- - v- - Steel 0xide n*
u
-. -+.. - CRP 60 E
v mg 50 8
2 40
.g O
- - - - - Ar-s e
30 E>
o
--.4---_-.--&_.-.
20
-_e - -
10 Li e
e-. - - e--
.e
.......p..... 3.... - +.g... zq, _- s - - ~_q- - -, - -
0 0.0 0.4 0.8 1.2 1.6 3
Time (10 min-Surry S3D (Pump Seal Leakage SBLOCA)
CPDPEGDNJ 3 / 16 / 9 3 15:4 8:10 MELCOR IBM-RISC Figure 5.4.10 Core Total Material Masses Predicted during S3D Sequence 139 NUREG/CR-6107
Results and Comparisons 1.0 r-n
-m a
n s
a n
=
UO2 s.
0.9
- e-ziracioy
-- E-- Zirc 0xide
{
0.8
_ 39,,j
A-----_a b
O
- - v- - Steel 0xide E
0.7
_._p.-
CRP o,.,
cn c
I~E 0.6 l
E i
.O 0.5 g
i.
._._._,s s,.-.
un 8
0.4 2
y
/L g
0.3
./
a o
1
-E 0.2 a
1 g
t..,
_ _ _ _ z._ _ _ _ _ _ _ g _ _ _ _ _ _.
0.1
.i er
'l W
0.0
'A 0.0 0.4 0.8 1.2
- 1. 6-3 Time (10 min
-Surry S3D (Pump Seal Leakage -SBLOCA)
CPDPEGDNJ 3 /16 / 9 3 15:4 8:10 -
MELCOR IBM-RISC
}
Figure 5.4.11 Core Fractional Material Masses Predicted during S3D Sequence I
NUREG/CR-6107 140 l
I
-~
Results and Comparisons 65 o
Ring 1l(COR.101) 60 Ring 2 (COR.201) 55 Ring 3 (COR.301)-
3 50 52 45 v
E 40 0
35 m
4 s
30
'E 25 1
20
+
O 15 u
10 o
x_
5 0
'0-
'^
c' 0
't 0.0 0.4 0.8-
- 1. 2-
- 1. @
3 Time (10 min)
Surry S3D (Pump Seal Leakage SBLOCA)
CPDPEGDNJ 3 /16 / 9 3 15:4 8:10 MELCOR IBM-RISC Figure 5.4.12 Lower Plenum Debris Bed Masses Predicted during S3D Sequence 141 NUREG/CR-6107 I
Results and Comparisons i
2.75 i
..i i
i i
i l
Ring 1 (COR.101);
2.50 Ring 2 (COR.201)
Ring 3 (COR.301) m 2.25 x
- oO 2.00
?>
j 1.75 n
15
/
q g 1.50 l
s 1.25 y
S h
l l 1.00
,a 15$ 0.75 g
e H
0 0.50 0.25 0.00
- ='
'0=
E:
-2 0.0 0.4 0.8 1.2 1.6 3
Time (10 min)
Surry S3D (Pump Seal Leakage SBLOCA)
CPDPEGDNJ 3 /16 / 9 3 15:4 8:10 MELCOR IBM-RISC Figure 5.4.13 Lower Plenum Debris Bed Temperatures Predicted during S3D Sequence l
L NUREG/CR-6107 142
Results and Comparisons 400 375 0
Basement 1
Cavity I I 350 7
SG Cubicles 325 Przr Cubicle
^
n
[
300 Dome o
......... STCP O
275 m
250 a
i r E
225 o.
200
-C.
E 175 l b i
150 e
o 125 100
~
75 f**
'~'~
^
50 O.0 0.4 0.8 1.2 1.6 Time (10 min) 3 Surry S3D (Pump Seal Leakage SBLOCA)
CPDPEGDNJ 3 /16 / 9 3 15:4 8:10 MELCOR ' IBM-RISC-Figure 5.4.14 Containment System Pressures Predicted during S3D Sequence I
143 NUREG/CR4107
l 1
Results and Comparisons c
J L
.1. 4 i
i i
i i
j !
0
. Basement 1"3 Cavity -
i SG Cubicles
^y 1.2 Przr Cubicle
^
o I
Dome 11 m
r
......... STCP
.e 1.0 t
ea.
~E 0.9 e
g 0.8 n
E d
q 0.7 C
l}
e 5
0.6 is.
g.
E 0.5
^
a a
=r-g g Jf o
0.4
'u! &'c L
0.3-0.0 0.- 4
.0. 8 1.2 1.6 3
Time (10 min)
Surry S3D (Pump Seal Leakage SBLOCA)
CPDPEGDNJ 3 /16 / 9 3 15:4 8:10 MELCOR IBM-RISC Figure 5.4.15 Containment System Atmosphere Temperatures Predicted during S3D Sequence NUREG/CR-6107 344
Results and Comparisons
- c. a, I.0 I
e i
1
-- m-- Sieom l
l
-- e -- N2 0.9 I
- e - 02 i
1 l
H2 0.. B i
-..e.. - CO 0.7 W ~ ~ ~ ~ 6. _ _
l
- -e- - CO2
,c
...s...
CH4 A
i
.9 b
{,,
'5 0.6 E
I s.
u-
[
l ]).
.e 0.5 OE l
o ll A J' IY-l
[
g 0.4 g
p A,,
!: ('Jk')*
0.3 Q'
I i
O.2
_._ y __ _, ' * -
1 A
b.
0*1
' - m - ' ~
{I Y'-S.~.~._.$.
^"f"-"1 e n..-----q.,-
"2
^
0.0 0.0 0.4 0.8 1.2 1.6 Time (10 min)~
3 Surry S3D (Pump Seal Leakage SBLOCA)
CPDPEGDNJ 3 /16 / 9 3 15:4 8:10 MELCOR lBM-RISC-Figure 5.4.16 Cavity Steam and Noncondensable Mole Fractions Predicted during S3D Sequence 145 NUREGICR-6107
'l q
Results and Comparisons i
i i
e i
i i
i
'o 7
- - m--
steam a
- e - N2
/,
- jA._
_~n I
- -* - 0 2 6
\\
l
\\
C O
s s
_. _e.- CO E
6 N
- - e- - CO2 o
5 s'~
u L-al
....f,...
CH4 s
si O
i s
4 I I e
E e'h O
/g Q
P i
3
,.R'~
-m-8 I
E
/~
- ~ ~ ~ ~ ~., s '
b i
5 i
R 2
^
/
O g ~~_ N -
e i
'd,
-e s
st 1
f '. _e-
-- y. 3.-
rp
%.:. 2 : ;,-g ac' y ':
O c
5:
ad c:t d
O.0 0.4 0.8 1.2 1.6 3
Time (10 min)
Surry S3D (Pump Seal Leakage SBLOCA)
CPDPEGDNJ 3 /16 / 93 15:4 8:10 -
MELCOR IBM-RISC Figure 5.4.17 Containnw.nt Donne Steam and Noncondemable Mole fractions Predicted during S3D Sequence NUREG/CR-6107 146
Results and Comparisons s
b 160
=
' Totol -
- o-in core 140
- -a - in.Covity g
o
-- E--
on Structures 120
- -o- - in ' Atmosphere -
- - v- - in Pool m
se:
100 3
n o
oe 80 1
Ao 8
60 I I o
40 20 1
\\
r - --6-- - - -- -4.= -. _..
j
-' ^
if ;~ ""* * - '
- ~-
0 0.0 0.4 0.8 1.2
- 1. 6 '
3 Time (10 min) j Surry S3D. (Pump Seal Leakage SBLOCA)
CPDPEGDNJ-3 /16 / 9 3 15:4 8:10 MELCOR IBM-RISC Figure 5.4.18 Decay Heat Predicted during S3D Sequence 147 NUREG/CR-6107
~!
Results and Comparisons 200 i
i i
i i
i i
- m-Total added by COR
-180
~
O Total in CAV
--A--
Gas released in CAV 160
- -H - Concrete ablated in CAV O
140 mg n9 120 v
/ * --- -
8-100 J
r 80 U
TC 60 4'~~~*~~
40
/
20
[
___&_______4____
- - ' - ^
" ~
0 O.0 0.4 0.8 1.2 1.6 3
Time (10 min)
Surry S3D (Pump Seal Leakage SBLOCA)
CPDPEGDNJ 3 /16 / 93 15:4 8:10 MELCOR IBM-RISC r
')
t Figure 5.4.19 Total Cavity Masses in Cavity Predicted during S3D Sequence NUREG/CR-6107 148 1
l
Results and Comparisons 140 e
i 130 0
H0X
~
1 LOX 120
~
MET 3
110
,x 52 100 v
g 90 o
80 t
o 70 a
.e 60
.E g
50 y
40 i
8 l
o 30 -
i 20 10 -
W 0
- ^ '
'-^
^'
i 0.0 0.4 0.8 1.2 1.6 3
Time (10 min)
Surry S3D (Pump Seal Leakage SBLOCA)
CPDPEGDNJ 3 / 16 / 9 3 15:4 8:10 MELCOR IBM-RISC Figure 5.4.20 Cavity Layer Masses Predicted during S3D Sequence 149 NUREG/CR-6107
6 MJ w aW ? G M > J34M M M *&
- ' A O,+2m'w'.w r sm--nd e=..* =W * ! w e 5
J{',
t.
F d
4 N
I
?" )
s' L
i l
f' l
l,i I,
i I
l E
I a
0 e
t w-d -:
i.
I I
I I <
I i
e I
.t k
?.'
i -.
'l t 4
I F
t-A P
s 0
a e
a
.d_m-_,----_.m----m--
--h--w
-. +,
)
Results and Comparisons e
- Cavity Minimum Depth 1.35 i
i 1.30 1.25-1.20 E
" 1. 1 5'
'1.10 1.05
/'
1.00 Cavity Maximum Radius 4.55 i
a l
4.50 l
4.45 E 4.40 v
4.35.
J 4.30 4.25 O.0 0.4 0.8
- 1. 2 -
- 1. 6 -
3 Time (10 min)
'Surry 'S3D (Pump Seal Leakage SBLOCA)
CPDPEGDNJ 3 /16 / 9 3 ;
15:4 8:10 MELCOR ' IBM -RISC Figure 5.4.23 Cavity Maximum Radius and Minimum Depth Predicted during S3D Sequence NUREG/CR4107 152 t
t
._,..-4
. ~. -
Results and Comparisons 6.5
='
=
Total from cavity 6.0
- e-H2 from Cavity
' g
- -.g 5.5
- e - H2O from Cavity
-- x-- C0 from Cavity 5.0 men 2
- -+- - CO2 from' Cavity 4.5 8
- o-H2 from-Core
/
-- E--
CO from Core m
4.0 em
- -<- - CO2 from Core
~
~ '
CH4 from Core
- - v- -
u 3.0 0
2.5
'\\
E u
H 2.0 n
-8 H
2 1.5 1.0 ll 0.5
" "-- '^
"/~-
YA-
" #Y 0.0 0.0 0. 4' O.8
- 1. 2'
.1. 6 3
Time (10 min)
-Surry. S3D (Pump Seal Leakage SBLOCA)
CPDPEGDNJ_
3 /16 / 9 3 15:4 8:10 MELCOR IBM-RISC Figure 5.4.24 Gas Generation Predicted in Core and in Cavity during S3D Sequence 153 NUREG/CR4107
Results and Comparisons Class 2 (Cs) 110 i
i i
i 100 0
0 0
_ _ _,_ _ _ _ _ v mb 90 Y
80
_C D
70
=C 60 a
v 8
50 u.
r 40 u-
. n
?
30 8
20 a:
r 10
' ~
~~7-7 ~ ~ '~
~
0 0.0 0.4 0.8 1.2 1.6 Time (10 rain)
- v--
Primary 3
~~ * ~ I"UY Surry S3D (Pump Seal Leaka'ge SBLOCA)
Total CPDPEGDNJ 3 /16 / 9 3 15:4 8:10
.MELCOR IBM-RISC 1
i Figure 5.4.26 Release of Class 2 (Cs) Alkali Metal Radionuclides from Fuel in Core and in Cavity Predicted during S3D Sequence, as Percentage of Initial Inventory in Core NUREG/CR-6107 156
i Resuhs and Comparisons Class 3 (Ba) 50 i
i i
i
-i f3
~
45 15 40 Ce 5
35
_v_
.o.
30
,r 25 25 20 E
t e
f3 15 m
r--<----&---
g 1
S 10
~
l f l 5
/
0 cf a 'c':
t i i
i 0.0' O.4 0.8 1.2 1.6 Time (10 min)
- v--
Primary 3
Surry S3D (Pump Seal Leakage SBLOCA)
- + - Cavny o
Total l
CPDPEGDNJ 3 /16 / 93 15:4 8:10 MELCOR IBM-RISC w mmmmmmmmmmmmmmmmum
. Figure 5.4.27 Release of Class 3 (Ba) Alkaline Earth Radionuclides from Fuel in Core and in Cavity during S3D Sequence, as Pementage of Initial Inventory in Core 157 NUREG/CR4107
Results and Compadsons i
Class 6 (Ru)
-1.8 i
i i
i 1.6
<r T'
r)
S 1.4 Fo
-g 1.2
.9
<r
._C I3 1.0 5
.2 0. 8' E
0.6 II 2
E 0.4
'r J
J 0.2
-0.0 Cf a
'O-
'i i
i' O. 0.
0.4 0.8 1.2 1.6 Time (10 min).
- v-Primary 3
Surry S3D (Pump Seal Leakage SBLOCA)
- +
CavHy C
- I CPDPEGDNJ 3 /16 / 9 3 15:4 8:10 MELCOR IBM-RISC Figure 5,4.30 Release of Class 6 (Ru) Platinoid Radionuclides from Puel in Core and in Cavity Predicted during S3D Sequence, as Percentage of Initiallnventory in Core NUREO/CR-6107 160
Results and Comparisons Class 7 (Mo) 20 W
M 18
(-
-y-
--g ns 8
16 a
y
?
l
.s 14
~.~_
i__
12 r
o a
10 T
(f 8
E y
O i
h a
6 4
o 80e 4
n::
r j
r 2
4____,____,
I
';i 0
Cf a
'C-O.0 0.4 0.8 1.2 1.6 Time (10 min)
--- v--. Primary 3
- + - Covny Surry S3D (Pump Seal Leakage SBLOCA)
Total CPDPEGDNJ 3 /16 / 9 3 15:4 8:10 MELCOR IBM-RISC i
Figure 5.4.31 Release of Class 7 (Mo) Early Transition Element Radionuclides from Fuel in Core and in Cavity Predicted during S3D Sequence, as Perrentage of Initial Inventory in Core
'l 161 NUREG/CR-6107
Results and Comparisons Class 10 (U)
.2.25 i
i_
i 2
m 2.00 mb n
2 5
1.75
_E_
5 1.50
_C ny M
1.25 n
l9 v
7 1.00 of 5 0.75 u
4:
o g 0.50 8
2 r
- 0.25
' ~ -
^ -
0.00 01 1
'C7 t-0.0 0.4
- 0. 8 1.2 1.6 Time (10 min)
- v-Primary 3 covHy Surry S3D (Pump Seal Leakage SBLOCA)
CPDPEGDNJ 3 /16 / 9 3 15:4 8:10 MELCOR IBM-RISC Figure 5.4.34 Release of Class 10 (U) Uranium Radionuclides from Fuel in Core and in Cavity Predicted during S3D Sequence, as Percentage of Initial Inventory in Core NUREG/CR4107 164
g.
~
Results and Comparisons P
Class '12 -(Sn) e a
a es y_
u
.<.-4 4.
w 70 a
T
<r a
60 2
t3 C.
.g
?
50
.5!q r
~
f)
M 40 v
g u.
0
,7 E
O r]
_u o
?
20 8
ej m
.r 10
' O v ' b
-- 4 -- - ' -- ~^ '- -- ' - ' - '
0 0f a
O.0 0.4 0.'8 1.2 1.6 Time (10 min)
- v-Primary-3 Surry S3D (Pump. Seal Leakage SBLOCA)
-- + - Ec m Hy U
III CPDPEGDNJ 3 /16 / 9 3 15:4 8:10 MELCOR. IBM-RISC-i
. Figure 5.4.36 Release of Class 12 (Sn) Less Volatile Main Group Radionuclides from Fuel in Core and in Cavity Predicted during S3D Sequence, as Percentage of Initial Inventory in Core 1
NUREG/CR-6107 166
Results and Comparisons Class 11 (Cd) i i
i m.
70 9
<r 8
60 r3 c
g
_G 50
.oE
<r
[]
40 e
30 r
E i
_2 I3
.o 3
20 8
w c$$
'r 10 53
'~'l'
~"
^
O 0.0 0.4 0.8 1.2
- 1. 6 -
3
- v-Primary Time (10 min)
-- * -- C VNY
~
Surry S3D (Pump Seal Leakage SBLOCA)
Totali CPDPEGDNJ 3 /16 / 9 3 15:4 8:10 MELCOR IBM-RISC musammmmmmmmmmmmme f.-
- Figure 5.4.35 Release of Class 1I (Cd) More Volatile Main Group Radionuclides from Fuel in Core and in Cavity Predicted during S3D Sequence, as Percentage of Initial Inventory in Core 165 NUREG/CR-6107
Results and Comparisons Class 1 (Xe) 100 g
,-+---g----,--
90 I
-D I
o C
80 s
-s 70
.9 l
.T C
60 E
50 I
5 l
.o E
40 4
m 25 h
i
.g 30 I
9,=
E 20 7
Total Released o
7
?-5
- D-Primary o
10 1
- e - Containment-a:
4p
--4--
Environment '
n N
I--
~-
^ "
- ' ^
0 0.0 0.4 0.8 1.2 1.6 3
Time (10 min)
Surry S3D (Pump Seal Leakage SBLOCA)
CPDPEGDNJ 3 /16 / 9 3 15:4 8:10 MELCOR IBM-RISC Figure 5.4.37 Distribution of Class I (Xe) Noble Gas Radionuclides in Primary System. Containment and Environment Predicted during S3D Sequence, as Percentage of Initial Inventory in Core 167 NUREG/CR-6107
i--
[
Results and Comparisons l'
L i
Class 2 (Cs) 110 i
i 100 L
h 90 l
E 80 9
.o_
4l i
70 ll 60 8
a+--s
_s_
=
I s
50 i
_o p
-e-_.__e
}
c
.e 40 7
o I
2 30 13 8
I 7
Total Released l
g 20
~
1 /
- D-Primary -
j d
- e - containment 10'
/
-- *-- Environment g
I 1.
0 01_c ' c -- E
.i 0.0 0.4 0.8 1.2 1.6 3
Time (10 min)
Surry S3D (Pump Seal Leakage SBLOCA)'
CPDPEGDNJ 3 /16 / 9 3 15:4 8:10 MELCOR IBM-RISC Figure 5.4.38 Distribution of Class 2 (Cs) Alkali Metal Radionuclides in Primary System, Containment and Environment Predicted during S3D Sequence, as Percentage of Initial inventory in Core NUREG/CR 6107 168
Results and Comparisons Class 3 (Ba) 50 Total Released I 7
45
- o-Primary 8
- e - Containment j
40
~
--A--
Environment
_C 35
-OE
-C i
30-
~
w p-w - -- o _ _
._o -
a 8
25 b
=;
_ _ _ _o.
r i
E 20
.e l
O I
I e
15 2
P R
b /
g.
10
/
.y
<r l
f 5
/
^ "" ~
' ^
0 O.0 0.4 0.8 1.2
.1. 6 3
Time (10 min) 1 Surry S3D (Pump Seal Leakage SBLOCA)
CPDPEGDNJ 3 /16 / 9 3 15:4 8:10 MELCOR IBM-RISC
)
i l
Figure 5.4.39 Distribution of Class 3 (Ba) Alkaline Earth Radionuclides in Primary System, Containment and Environment U
during S3D Sequence, as Percentage of Initial Inventory in Core 169 NUREG/CR-6107
]
1 i
'Results and Comparisons Class 4 (1) 100 c-I 90 mt I
co c
80 P
_C 70 H
- =
p 60 8
50 l
l
.=
.5 l
3 40 4
m5 h
i I
.g 30 l
20 I
T
. Total Released-I 95 Primary O
1
- e - containment m
jo 4p
--A--
Environment-
^""^
'^#
0 0.0 0.4 0.8 1.2 1.6 3
Time (10 min)
.Surry S3D (Pump Seal Leakage SBLOCA)
CPDPEGDNJ 3 /16 / 9 3 15:4 8:10 MELCOR IBM-RISC Figure 5.4.40 Distribution of Class 4 (1) Halogen Radionuclides in Primary System, Containment'and Environment Predicted during S3D Sequence, as Percentage of Initial Inventory in Core NUREG/CR-6107 170
. -.-m.
m
,i i
. Results and Comparisons -
U 1
a.
l 1
Class 5 (Te) 65 i
i i
i i
i i
i 60 Total Released.
~
. Primary m>-g 55
_ e - containment
~
, 7 50
--A--
Environment
_c 3
45 i
=
i 5
40
- + -' ~ ~ + ~ ~
1 n.
/
~
35 I
8 9
5 30 1
S 1
j 25 4
o e-
- o- - -a - -
e 20 I'
a P
l 15 I
C a
O I
- j 10 1
,d 5
0 0fic
'Ovd l
i
'i 0.0 0.4 0.8 1.2 1.6 3
Time (10 min)
Surry :S3D (Pump Seal Leakage SBLOCA)
'CPDPEGDNJ 3 / 16 / 9 3 15:4 8:10 MELCOR. IBM-RISC Figure 5.4.41 Distribution of Class 5 (Te) Chalcogen Radionuclides in Primary System, Containm Predicted during S3D Sequence, as Percentage of InitialInventory in Core 171 NUREGICR-6107
^~
. ~. -... -.
= -
Results and Comparisons :
Class 6 (Ru) 1.8 7
Total Released g
1.6 Primary
,r
- -e - Containment
.,o_
E 1.4
--A--
Environment E
I - e- - - o- - --a l}
~O=
1.2 E
u D
1.0 C
.2 1
'l 3
0.8 O
4 m
o 0.6 e
.T E
l b g
0.4 I __ _o _ __ __ _ e __ _ __ __ e_.
o
- s v
f 0
m 0.2 f
L l
/
i' i
'i 0.0 0110
'O73 0.0 0.4 0.8 1.2
-1.6 3
Time (10 min)
Surry 'S3D (Pump _ Seal L'eakage SBLOCA)
CPDPEGDNJ 3 /16 / 9 3 15:4 8:10 MELCOR IBM-RISC Figure 5.4.42 Distribution af Class 6 (Ru) Platinoid Radionuclides in Primary System, Containment and Environmen 4
Predicted during S3D Sequence, as Percentage ofInitial Inventory in Core
- NUREG/CR-6107 172 l.
l
-t
b Results and Comparisons Class 7 (Mo) 20
?
Total Released 7
7
~
~
g
- D-Primary -.
- e - Containment o
,7 j
16
--A--
Environment
_E 14
.9 P
- e -- - a--
q 12
't I
E 10
.5 V
.c I
5 8
P 5
Q i
e - - - - - e- - -
e 6
2 9
1 5 e g
I g
4
-s
<r
/
O d
2
/
^ " ' - ' ^ -
0 O.0 0.4 0.8 1.2
- 1. 6 -
3 Time (10 min)
Surry S3D (Pump Seal Leakage SBLOCA)
CPDPEGDNJ 3 /16 / 9 3 15:4 8:10 MELCOR IBM-RISC Figure 5.4.43 Distribution of Class 7 (Mo) Early Transition Element Radionuclides in Primary System, Containment and Environment Predicted during S3D Sequence, as Percentage of Initial Inventory in Core 173 NUREG/CR-6107
~
Results and Comparisons Class 8-(Ce) i I
I i
i i
I 3
35 Total Released 7
m h
- D-Primary -
c
- e - Containment
'I j
30
--A--
Environment 6
=
- e--
- - D -
--a 5
25 gt 4
I-8 20 I
g-
)
=
15 L
A
.9 l
o a>
10 8
6
_ 4_
.-.e -- - -- - s..
1 1
k
' I 5
,d o
x O
^""-
' ^ - ' '
O.0 0.4 0.8 1.' 2
- 1. 6 '
3 Time (10 min)
-Surry S3D (Pump Seal Leakage SBLOCA)
- CPDPEGDNJ 3 /16 / 9 3 15:4 8:10 MELCOR IBM-RISC Figure 5.4.44 Distribution of Class 8.(Ce) Tetravalent Radionuclides in Primary System, Containment and Environment Predicted during S3D Sequence, as Percentage of Initial Inventory in Core NUREG/CR-6107 174
Results and Comparisons Class 9 (La) 5.5
~
Total Released T
5.0
-D-Primory g
"c
- e - Containment e
4.5
--A--
Environment
_E_
3 4.0
_e____e___4
.-g 3.5 1
34
'r 1
52 3.0 p
v I
c
.9 2.5 I
- a I
o E
2.0
.E!o
.e.
s__ _ ___ o_.
1.5 l
.o IF 15 E
1.0 i
O
- i5 e
0.5 Y'l i'
i
'a O.0 0110 ' O -
0.0 0.4 0.8 1.2 1.6 3
Time (10 min)
Surry S3D (Pump Seal Leakage SBLOCA)
CPDPEGDNJ 3 / 16 / 9 3 15:4 8:10 MELCOR IBM-RISC f
l Figure 5.4.45 Distribution of Class 9 (La) Trivalent Radionuclides in Primary System, Containment and Environment Predicted during S3D Sequence. as Percentage of InitialInventory in Core 175 NUREO/CR4107
Results and Comparisons Class 10 (U) 2.25 7
Total Released b 2.00
- a-Primary O
c
- e - Containment
'7 e
.E 1.75
--A--
Environment
--e
-e- - - s-
.9_
13 i
1.50 ke k1.25 C
8 1.00 Il 2e&
< r
.e 0.75 Q
3._.-o- - - - -e - - - - e- -
-g 0. 5 0 E
I
.9
< rg I
i 0.25 6
x 1
0.00
^ "^- ' ^
O.0 0.4 0.8 1.2 1.6 3
Time (10 min)
Surry S3D (Pump Seal Leakage SBLOCA)
CPDPEGDNJ 3 /16 / 9 3 15:4 8:10 MELCOR IBM-RISC Figure 5.4.46 Distribution of Class 10 (U) Uranium Radionuclides in Pnmary System, Containment and Environment Predicted during S3D Sequence, as Percentage of Initial Inventory in Core NUREG/CR-6107 176
Results and Comparisons Class 11-(Cd) i i
70 Total Released g
- D-Primary o
- e - Containment
'r j
60
--A--
Environment
~
fc
{ e- - - e- - - o 50 I
o
-;=
l B.
I AD
~
~
cO P
B.
1 A
30 y
.!2 o-
]
20 i3 g____,____g_
>c J
- -B
,r 1
o 10 d
1
^"""
' ^
0 O.0 0.4 0.8 1.2
- 1. 6.
h 3
Time.(10 min)
Surry S3D (Pump Seal Leakage SBLOCA)
CPDPEGDNJ 3 /16 / 9 3 -
15:4 8:10
'.MELCOR IBM-RISC Figure 5.4.47 Distribution of Class 11 (Cd) More Volatile Main Group Radionuclides in Primary System. Containment and Environment Predicted during S3D Sequence, as Percentage of Initial inventory in Core 177 NUREG/CR-6107
- Results and Comparisons Class 12 (Sn) i i
i m
T Total Released 70
- Primary m
w 8
- -e - Containment ~
lr j
60
~
--A--
Environment L
a--
- - D-
-D-50 "E
< J' 94 I
~
40 CO p.
-g
_o 30
.E!
o 20 g
_o.- - - - e - - - - o- -
5g 1
E
'r l o
10 d
1
' ^
^ "
E 0
O.0 0.4 0.8 1.2 1.6 3
Time (10 min)-
.Surry S3D (Pump Seal Leckage SBLOCA)
CPDPEGDNJ 3 /16 / 9 3 15:4 8:10 MELCOR IBM-RISC Figure 5.4.48 Distribution of Class 12 (Sn) Less Volatile Main Group Radionuclides in Primary System, Containment and Environment Predicted during S3D Sequence, as Percentage ofInitial Inventory in Core NUREG/CR-6107 178 t
s
4 Results and Comparisons 650 600
=
Tolol Released 550
~
- o-Total in Pool /Atms
- -e - Aerosol in Pool /Atms 500 9
--E--
Vapor in Pool /Atms d5 450
~
--w-Total on Hs n
8 400
- -8
{/
s
~~~ - ~~
- O'-
s 350 t
i s
/
-8 300
[
/...- -
~
~
~~
~
~
250 i
/!
'8 li !
s 200 in LA.
I g'
150 e
iNJ1 g j/
7
- ~ ~~ - -- - - - - '
100
\\v (l
50
(
0 O.0 0.4 0.8 1.2 1.6 3
Time (10 min)
- Surry S3D (Pump Seal Leakage SBLOCA)
CPDPEGDNJ 3 /16 / 9 3 15:4 8:10 MELCOR IBM-RISC Figure 5.4.49 Total Fission Product Mass Released, and Overall Distribution, Predicted during S3D Sequence 179 NUREG/CR-6107
j 6 Summary and Findings This report summarizes the results from three MELCOR pressurization rate and partly due to a highcr # Nre calculations of nuclear power plant accident sequences pressure setpoint. After containment failure and assc ed performed in support of the NRC's updated regulatory loss of ECC, both codes predicted core damage, sower source term and presents comparisons with Source Term head failure, and debris ejection to the cavity. The core Code Package (STCP) calculations for the same degradation process calculated by MELCOR was sequences. The program task was to run the MELCOR somewhat more gradual and extended than that predicted i
program for three low-pressure sequences to identify the by STCP. Both codes predicted almost all the noble gases materials which enter containment (source terms) and are and alkali metal volatiles (CsOH) released, and most ofthe available for release to the environment, and to obtain halogens (1). Significantly more alkali earth (Ba) release E
timing of sequence events. The source terms include and significantly less Tellurium (Te) releases were fission products and other materials such as those calculated by MELCOR than by STCP. A small fraction generated by core-concrete interactions.
All three (s5%) of the Mo, Cd and Sn were calculated to be l
calculations, for both MELCOR and STCP. analyzed the released in the MELCOR analysis, with no STCP values l
Surry plant, a pressurized water reactor (PWR) with a for comparison. Both codes predicted only trace amounts j
subatmospheric containment design.
of the refractories (Ru, Ce, La and U) to be released.
The AG sequence, a large break LOCA, assumed the Fission product release results from STCP were not 4
availability of both passive and active Emergency Core available for the S2D and S3D sequences for comparison Cooling System (ECCS) safety systems for protection of to MELCOR predictions. Therefore, only timings of the primary system. Containment protective systems major events could be compared in these two cases, available for use included the containment fan coolers and Neither code predicted containment failure in either case, containment sprays. Since the containment recirculation primarily due to the continued availability for containment spray system coolers were inoperable, there was no heat removal da the containment spray recirculation capability for containment heat removal as the accident system coolers. ume to core uncovery, core damage and progressed. The snud! break LOCA sequences, S2D and relocation, lower head failure and debris ejection to the S3D, assumed the ECCS systems were unavailable, with cavity were not all that different. One major difference the exception of the passive accumulators. For those two between results from from MELCOR and from STCP was
?
accident sequences, the containment spray systems were the prediction of deflagrations occurring in both sequences fully operable, including the capability for containment in the MELCOR analyses, with associated containment heat removal via the containment spray recirculation pressure and temperature spikes; there were no system coolers.
Since each of the three accident deflagrations in the STCP analyses for either small break sequences progressed through core melt, core slumping, sequence.
reactor vessel failure, and ex-vessel core-concrete interaction, they provided a good test of the ability of The overall fission product source terms calculated by MELCOR to simulate integrated accidents that progressed MELCOR for the S2D and S3D sequences, and for the to the point of radionuclide release to the containment or AG sequence as well, showed some general similarities in environment.
predicted response. In all three cases almost all of the noble gases (2 99%) and most (~ 85-95 %) of the Cs and 1
There were no major differences in the behavior predicted I volatiles were released; very little remained in the RCS for the AO large break LOCA sequence. Both MELCOR and almost all were in the containment or (for the AG and STCP predicted a slow pressurization of containment sequence) released to the environment. Intermediate as the ECCS water delivered to the core is boiled off amounts of Ba, Te, Sn, Cd and Sn (2-30%) were removing the decay heat. The containment was predicted released, and only trace amounts (sl%) of the to fail slightly later in time in the MELCOR calculation refractories Ru, Ce, La and U were predicted to be than in the STCP analysis, partly due to a slower released.
l 4
NUREG/CR-6107 180
References 1.
Denning, R. S. et al., "Radionuclide Release Calculations for Selected Severe Accident Scenarios," NUREG/CR-4624, BMI-2139, Battelle Columbus, Vol. 3: PWR, Subatmospheric Containment Desien. July 1986, and Vol. 6:
Sunnlemental Calculations, August 1990.
2.
Summers, R. M. et al., MELCOR 1.8.0: A Computer Code for Nuclear Reactor Severe Accident Source Term and Risk Assessment Analyses, NUREG/CR-5531, SAND 90-0364, Sandia National Laboratories, Albuquerque, NM, January 1991, 3.
Gieseke, J. A. et al., Source Term code Packace: A User's Guide, NUREG/CR-4587, BMI-2138 Battelle Columbus Laboratory, July 1986 4.
USNRC, Reactor Risk Reference Document. NUREG-1150, Office of Nuclear Regulatory Research, U. S. Nuclear Regulatory Commission, February 1987, 5.
Breeding, R. J. et al., Evaluation of Severe Accident Risks: Vol. 3. Rev. l. Pt.1: Surry Unit 1, NUREG/CR-4551, SAND 86-1309, Sandia National Laboratories, Albuquerque, NM, October 1990.
6.
USNRC, Reactor Safety Study -- An Assessment of Accident Risks in U. S. Commercial Nuclear Power Plants,-
WASH-1400 (NUREG-75/014), U. S. Nuclear Regulatory Commission, October 1975.
7.
Internal Memorandum from R. J. Dallman to R. D. Copp, "MELCOR Preliminary Evaluation", RJD-50-87, Idaho National Engineering Laboratory, December 28, 1987.
8.
Letter from C. A. Dobbe, INEL, to J. E. Kelly, SNL, " Transmittal of Calculational Workbooks for the MELCOR Input Decks of the Surry PWR", CAD-1-88, May 6,1988.
9.
Letter from C. A. Dobbe, INEL, to J. E. Kelly, SNL, " Transmittal of Floppy Disk Containing the MELCOR Input -
Decks of the Surry PWR", CAD-2-88, May 17,1988.
10.
- Bayless, P. D., Analyses of Natural Circulation Durine a Surry Station Blackout Usine SCDAP/RELAP5, NUREG/CR-5214, EGG-2547, Idaho National Engineering Laboratory, October 1988.
11.
Smith, P. N. and Mason, P. L., AEA Assessment of MELCOR 1.8.1 Usine Calculations for TMLB' Accident Secuengs, AEA RS 5484, UK AEA Winfrith Technology Centre, March 1993.
12.
L. N. Kmetyk, MELCOR 1.8.2 Assessment: Surry PWR TMLB' (with a DCH Study), SAND 93-1899, Sandia National Laboratories, Albuquerque, NM, March 1994.
181 NUREG/CR-6107
Distribution General Electric Company (3)
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Attn:
M. L. Corradini Attn:. Mark Riley.
Engineering Research Building G. A. Moses Jow Semanchik' Vincent Baiamonte 1500 Johnson Drive P.O. Box 79 Madison, WI 53706 West Mifflin, PA 15122 Ramu K. Sundaram Mohsen Khatib-Rahbar Manager, LOCA Analysis Group Energy Research Inc.
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NUREG/CR-6107 182 l
1
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~
~
Dr. Bohumfr Kujal -
Attn: : Ulrich Erven -
I Gescelschaft fur Anlagen-und Reaktorsicherheit (3)
Department of Reactor Technology -
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- Dr. Susumi Sugeri, Director General Univer:sidad Politecnica de Mcdric (2) 1 Jcpan Institute of Nuclear Safety :
Attn:
Augustin Alonzo Santos Fujita Kankou Toranoman Illdg. 7F Francisco Martin
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'6418 A. A. Elsbernd 6418 L. N. Kmetyk (10) 6418 R. S. Longenbaugh 6418 R. C. Smith 6418 R. M. Summers 6418 T. J. Tautges 6429 K. E. Washington 7141 Technical Library (5) 7151 Technical Publications 8523-2 Central Technical Files 1
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2 mLE ANo sustmt SAPD93-2042 Summary of MELCOR 1.8.2 Calculations for Three LOCA Sequences..( AG, S2D, 'and S3D) at the Surry Plant 3-DATE"0"s55 C l
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2 Albuquerque, NM 87185 2201 Buena Vista, NM 87185 Albuquerque, NM 87106
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Division of Safety issue Resolution Office of Nuclear Regulatory Research U,S. Nuclear Regulatory Commission Washington, DC 20555-0001
- 10. SUPPLEMENTARY NOTES
- 11. ABSTR ACT rJoo e,si or arur Activities involving regulatory implementation of updated source term information were pursued. These activities include the identification of the source term, the identification of the chemical form ofiodine in the source term, and the timing of the source term's entrance into containment. These activities are intended to support a more realistic source term for licensing nuclear power plants than the current TID-14844 source term and current licensing -
assumptions. MELCOR calculations were performed to support the technical basis for the updated source term.
~ This report presents the results from three MELCOR calculations of nuclear power plant accident sequences and presents comparisons with Source Term Code Package (STCP) calculations for the same sequences. The three low-pressure sequences were analyzed to identify the materials which enter containment (source terms) and are available for release to the environment, and to obtain timing of sequence events. The source terms include fission products and other materials such as those generated by core-concrete interactions. All three calculations, for both MELCOR l,
and STCP, analyzed the Surry plant, a pressurized water reactor (PWR) with a subatmospheric containment design;
- 12. r,t Y woRDs ot sc R:Pt oR s u... <. w e<-* e** -a, a=,-aa= = =w-s 'a =-o oavus'un5'os e Unlimited LOCA Analyses
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