ML20073K921
| ML20073K921 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 09/30/1994 |
| From: | Binder J, Mcumber L, Spencer B ARGONNE NATIONAL LABORATORY |
| To: | NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| References | |
| CON-FIN-A-2266 ANL-94-18, NUREG-CR-6168, NUDOCS 9410120216 | |
| Download: ML20073K921 (112) | |
Text
NUREG/CR-6168 ANL-94/18 Direc~: Containmerr: Heating Integra Efec~:s Tests a~:
1/LO Sca e in Zion Nuclear Power P ant Geome:ry l'reparn! by J. [.. Itinder I. M MctJn:bcr. IL W. Spencer Argonne National 1.aboratory l'repared for U.S. Nuclear Regulatory Conunission EsA2!881R3183Ls P
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NUREG/CR-6168 ANL-94/18 Direct Containment Heating l
Integral Effects Tests at 1/40 Scale in Zion Nuclear Power Plant Geometry i
4 1
ii i
1 Manuscript Completed: April 1994
.j Date Published: September 1994 s
s f
Prepared by l
J. L Binder, L M. McUmber, B. W. Spencer i!
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j Argonne National Laboratory f
9700 South Cass Avenue
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Argonne, IL 60439 1
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- j Prepared for a
Division of Systems Research fI Ollice of Nuclear Reactor Research l
U.S. Nuclear Regulatory Commission I
Washington, DC 20555-0001 NRC FIN A2266 I
i j
I ABSTRACT The results of Direct Containment Heating (DCH) integral experiments are presented. The experiments simulated a high pressure melt ejection in the Zion Nuclear Power Plant. Experiments were conducted in a 1/40 scale model of the Zion containment. The model included the vessel lower head, cavity and instrument tunnel, and the lower containment structures. The melt ejections were driven by steam.
There were two main objectives of these experiments. The first was to investigate the efTect of scale on DCH phenomena. The IET test series addressed this by conducting counterpart integral tests in a 1/40 scale facility at Argonne National Laboratory and in a 1/10 scale facility at Sandia National Laboratories. Iron-alumina thermite with chromium was used as a core melt simulant in the IET test series. The second objective was to address potential experiment distonions introduced by the use of non-prototypic iron /alurrUta thermite. The second objective was met in the U series of tests which utilized a prototypic core melt. Corium experiments were conducted that were counterpart to the IET-lRR and IET-6 iron / alumina tests.
I iii NUREG/CR4168 J
CONTENTS SECTION PAGE ABSTRACT iii EXECUTIVE
SUMMARY
xiii i
INTRODUCTION 1
2 EXPERIMENT DESCRIPTION 3
2.1 Facility Description 3
2.2 Apparatus Description 3
2.2.1 Zion Cavity Model 8
2.2.2 Subcompartment Model 8
2.2.3 Steam Delivery System 8
2.3 Diagnostics 8
2.3.1 Pressure Measurements 8
2.3.2 Temperature Measurements 8
2.3.2.1 Subcompartment and Expansion Vessel Gas Temperature Measurements 8
2.3.2.2 Cavity Gas Temperature Measurements 8
2.3.3 Melt Ejection Indication 13 2.3.4 Visualization 13 2.3.5 Gas Composition Measurements 13 2.3.6 Debris Disposition Measurements 13 2.3.7 Data Acquisition and Reduction 13 2.4 Test Procedures and Operations 13 2.4.1 Pretest 13 2.4.2 Test 13 NUREG/CR-6168 y
i 2.4.3 Posttest 14 2.5 Core Melt Simulant Characterization 14 2.5.1 Prototype Core melt Composition 14 2.5.2 Experiments Simulants 14 2.5.2.1 Iron / alumina Thermite with Chromium 14 2.5.2.2 Experimental Corium 16 2.5.3 Scaling Considerations 19 3
EXPERIMENT RESUI.TS 29 3.1 Objectives 29 3.2 Test Initial and Boundary Conditions 29 3.2.1 Selection of NPP and Accident Sequence 29 3.2.2 Hole Diameter 29 3.2.3 Melt Mass 30 3.2.4 Driving Steam 30 3.2.5 Containment Atmosphere Conditions 31
)
3.2.5.1 Containment Conditions for IET-1, IR and IRR 31 3.2.5.2 Containment Conditions for IET-3 31 3.2.5.3 Containment Conditions for IET-6 31 3.3.5.4 Containment Conditions for IET-7 32 3.2.5.5 Containment Conditions for IET-8 32 3.2.5.6 Containment Conditions for Ul A and UlB 32 3.2.5.7 Containment Conditions for U2 32 3.2.6 Cavity Water 32 3.3 Test Results 32 3.3.1 Primary System Blowdown 32 3.3.2 Pressure Measurements 36 NUREG/CR4168 vi
=
3.3.2.1 Contoinment Loads 36 3.3.2.2 Cavity Pressure Histories 39 3.3.3 Temperature Measurements 39 3.3.3.1 Cavity Gas Temperatures 39 3.3.3.2 Subcompartment Gas Temperatures 39 3.3.3.3 Containment Gas Temperatures 39 3.3.4 Gas Composition Measurements 69 3.3.5 Debris Disposition Measurements 69 3.3.6 Particle Size Measurements 69 4
DISCUSSION AND ANALYSIS 77 4.1 Cavity Sweepout Phenomena 77 4.2 Hydrogen Production and Combustion 77 4.3 Comparison of Corium and Iron-Alumma Thermite Simulants 83 5
SUMMARY
AND CONCLUSIONS 85 6
REFERENCES 87 Appendices APPENDLX A A1 l
vii NUREG/CR-6168 i
}
LIST OF FIGURES Figure Page 2.1 The Corium Ex-vessel Interaction (COREXIT) Facility 4
2.2 Zion Cavity Model 5
2.3 Schematic of the Melt Generator and Injector 6
2.4 Internal Cavity Dimensions 7
2.5 Three-dimensional view of the Zion Subcompartment Model 9
2.6 Cross-sectional view of the Zion Subcompartment and Cavity Model 10 2.7 Aspirated Thermocouple Assembly 11 2.8 Corium Simulant Temperature Measured with Type C Thermocouples 17 2.9 Corium Simulant Temperature Measured with a Pyrometer 18 2.10 Melt Specific Enthalpy 20 2.11 Scaling Calculation for the Zion NPP 23 2.12 Scaling Calculation for the Experiment with iron-Alumma Thermite 24 2.13 Scaling Calculation for the Experiment with Corium.
25 3.1 Typical Blowdown Sequence Obtained in the Tests 33 3.2 Primary System Blowdown Histories Obtained in the Tests 34 3.3 Rate of Change of Steam Moles in the Pnmary System 35 3.4 Containment Loads Obtained in the ET Experiments 37 3.5 Containment Loads Obtained in the Corium Experiments 38 3.6 Cavity Pressure History Obtained in ET-lRR 40 3.7 Cavity Pressure History Obtained in ET-3 41 3.8 Cavity Pressure History Obtained in ET-6 42 3.9 Cavity Pressure History Obtained in ET-7 43 3.10 Cavity Pressure History Obtained in ET-8 44 3.11 Cavity Pressure History Obtained in UIA 45 NUREG/CR-6168 viii
3.12 Cavity Pressure History Obtained in UlB 46 3.13 Cavity Pressure History Obtained in U2 47 3.14 Cavity Gas Temperature Measured in ET-3 48 3.15 Cavity Gas Temperature Measured in IET-6 49 3.16 Cavity Gas Temperature Measured in ET-7 50 3.17 Cavity Gas Temperature Measured in Ul A 51 3.18 Cavity Gas Temperature Measured in UlB
$2 3.19 Subcompartment Gas Temperatures Obtained in ET-lRR 53 3.20 Subcompartment Gas Temperatures Obtained in ET-3 54 3.21 Subcompartment Gas Temperatures Obtained in ET-6 55 3.22 Subcompartment Gas Temperatures Obtained in ET-7 56 3.23 Subcompartment Oas Temperatures Obtained in ET-8 57 3.24 Subecmpartment Gas Temperatures Obtained in UIA 58 3.25 Subcompartment Gas Temperatures Obtained in UlB 59 3.26 Subcompartment Gas Temperatures Obtained in U2 60 3.27 Upper Dome Gas Temperatures Obtained in ET-lRR 61 3.28 Upper Dome Gas Temperatures Obtained in ET-3 62 3.29 Upper Dome Gas Temperatures Obtained in ET-6 63 3.30 Upper Dome Gas Temperatures Obtained in ET-7 64 3.31 Upper Dome Gas Temperatures Obtained in ET-8 65 3.32 Upper Dome Gas Temperatures Obtained in UI A 66 3.33 Upper Dome Gas Temperatures Obtained in U1B 67 l
3.34 Uppec Dome Gas 'empecstures Obtained in U2 68 3.35 Particle Size Dissibution of Debris Dispersed to the Upper Dome in ET-IRR 73 3.36 Particle Size Distribution of Debris Dispersed to the Upper Dome in ET-3 74 l
3.37 Particle Size Distribution of Debris Dispersed to the Upper Dome in ET-6 75 ix NUREG/CR-6168 l
3.38 Particle Size Distribution of Debris Dispersed to the Upper Dome in IET-7 76 4.1 Comparison of the Cavity Sweepout for ET4 and UI A 78 4.2 Comparison of the cavity Sweepout for ET4 and UIA in Dimensionless Form 79 4.3 Estimated Coberence Factors as a Function of the Cutoff Cavity Pressurization 80 4.4 Plot of the Oxygen and Hydrogen Moles in IET4 and U2 82 l
i NUREG/CR4168 x
LIST OF TABLES Table Page 2.1 Instrumentation 12 2.2 Synthesized Molten Melt Composition for an Instrument Tube Penetration Failure at Surry from Levy (1992) 15 2.3 Summary of Core Melt and Simulant Compositions (mass fraction) 15 2.4 Oxidation Characteristics of Melt Simulants with Steam 21 2.5 Assumed Initial Conditions Used in Melt Mass Scaling Calculations 26 2.6 Required Melt Mass to Satisfy Energy / Volume Scaling 26 2.7 Fractional Contribution to DCH Maximum Load 26 3.1 Summary of Specified Reference Initial and Boundary Conditions 30 3.2 Experiment Initial Conditions 31 3.3 Summary of Test Results 36 3.4a Gas Composition Measurements-Hydrogen Concentration in mole %
70 3.4b Gas Composition Measurements-Oxygen Concentration in mole %
71 3.5 Debris Disposition Measurements 72 3.6 Particle Size Measurements 72 4.1 Hydrogen Production and Combustion 81 A.1 Gas Bottle Analysis for IET-IRR 92 i
A.2 Gas Bottle Analysis for IET-3 93 A.3 Gas Bottle Analysis for IET-6 94 A.4 Gas Bottle Analysis for IET-7 95 A.5 Gas Bottle Analysis for IET-8 96 A.6 Gas Bottle Analysis for UIA 97 A.7 Gas Bottle Analysis for UlB 98 A.8 Gas Bottle Analysis for U2 99 xi NUREG/CR-6168 1-
EXECUTIVE
SUMMARY
The results of Direct Containment Heating (DCH) integral experiments are presented. The experiments simulated a high pressure melt ejection in the Ziou Nuclear Power Plant. Experiments were conducted in a 1/40 scale model of the Zion containment. The model included the vessel lower head, cavity and instrument tunnel, and the lower containment structures. The experiments were driven with steam.
There were two main objectives of these experiments. The first was to investigate the effect of scale on DCH phenomena. The IET test series addressed this by conducting counterpart integral tests in a 1/40 scale facility at Argonne National Laboratory and in a 1/10 scale facility at Sandia National Laboratories. Iron-alumina thermite with chromium was used as a core melt simulant in the IET test series. The second objective was to address potential experiment distortions introduced by the use of non-prototypic iron /alumma thennite. The second objective was met in the U series of tests which utilized a prototypic core melt. Corium experiments, UlB and U2, were conducted that were counterpart to the IET-lRR and IET4 iron /alumma tests, respectively.
This document provides a description of the experimental results. A detailed analysis of the tests is not undertaken herein. The two main objectives stated above were met. In addition to meeting the objectives, with regard to xale and melt simulant distortions, two specific findings were obtained. These are listed below.
1.
The subcompartment structures efficiently trapped 90 percent of the debris leaving the casity. This causes the extent of debris / atmosphere interactions to be significantly reduced. In the limit of complete trapping the DCH load is confined to the heat up of the blowdown gasses during the melt sweepout process.
2.
Comparison of counterpart iron /alumma and corium tests indicated a very small effect of non-prototypic melt simulant on the measured DCH load.
xiii NUREG/CR-6168
ACKNOWLEDGEMENTS This work was funded by the U. S. Nuclear Regulatory Commission. The support and guidance of the NRC program managers, R Lee and C. Tinkler, is gratefully acknowledged. The efforts of R. Wesel and B. Banez were instrumental in carrying out the experiments. "Ihe efforts of D. Kilsdonk in preparing the figures of the tests apparatus is appreciated. The gas sample analysis was carried out by the late T. Engelkemier of the Analytical Chemistry Division at ANL, the careful analysis is appreciated.
i l
1 1
NUREG/CR4168 x;y
1 IhTRODUCTION 1 INTRODUCTION Risk studies of U. S. nuclear power plants addition of gas moles to the containment atmosphere, have focused attention on low probability, beyond Water vaporization is, therefore, a source of design basis, severe accidents. These accidents additional containment pressurization. However, for involve a core melt, relocation to the vessel lower most cases, the net effect of debris quenching is an head, failure of the lower head, and release to the energy sink. The third source of energy to the containment. The release of the molten core material containment is the release of chemical energy in the (corium) to the containment can produce thermal or corium via metal oxidation reactions with steam or pressure loadings that pose a threat to the integrity of oxygen. This energy source may be significant if the the containment. Ofinterest here is a corium release corium released from the vessel contains a significant in a PWR while the vessel is at elevated pressure, in fraction of " reactive" metal. In the prototype case the such a case the corium will be forcibly ejected into reactive metal is predominantly zirconium and the containment cavity. An event of this type is possible small mounts of chromium from stainless termed a High Pressure Melt Ejection (HPME). The steel structures in the core. These metals readily fundamental question then becomes: Will the HPME have exothermic reactions with steam or oxygen at cause an energy transfer to the containment high temperatures. The corium may also contain atmosphere large enough to produce a pressure load significant amounts of metal iron, however, the that threatens the containment integrity? The transfer oxidation reactions with iron and steam are only of energy to the containment atmosphere is termed slightly exothermic. The oxidation reactions ofiron Direct Containment Heating (DCH).
and oxygen are significantly exothermic; however, due to the HPME process the melt interacts almost The sources and mechanisms for direct exclusively with a steam atmosphere. Therefore, iron containment heating will be described below. There oxidation does not present a significant energy are four sources of energy to the containment source. The oxidation of the metal is expected to atmosphere.
The first is the addition of the occur mainly in the cavity where highly fragmented blowdown gasses (steam and hydrogen) from the melt is intimately mixed with high velocity steam reactor coolant system (RCS) to the containment.
exiting the primary system. The fourth source of The mass of gas in the RCS is typically an order of energy to the containment is the combustion of magnitude less than the mass of gas in the hydrogen. There may be three sources of hydrogen containment. Therefore, the blowdown source of in the containment.
Hydrogen may be in the energy to the containment is negligible. The transfer containment pre-existing to the HPhE due to in-l of the corium thermal energy to the containment, vessel zirconium oxidation and then subsequent l
debris / gas heat transfer,is a second source of energy.
release from the primary system to the containment.
l The blowdown of the primary system gasses into the In-vessel oxidation also leads to hydrogen in the cavity will fragment and disperse the corium out of blowdown gasses which is a second source of the cavity into the containment. In general this hydrogen to the containment. The third source of source of energy will be a significant DCH hydrogen is from the metal steam reactions during the contributor for HPMEs. However, it is expected that debris dispersal phase of the HPhE and blowdown.
the efficiency of this debris / gas heat transfer will Hydrogen combustion may be a significant source of increase with debris flight path. The presence of energy, possibly the dominant one, to the many lower compartment structures in the containment.
containment building can trap debris, reducing the flight path and consequently lead to significant The NRC has been sponsoring a research mitigation of the debris / gas heat transfer. A second program to resolve the DCH issue. An important part mitigation of the debris / gas heat transfer can occur of this effort is an integral effects testing program. In due to quenching of the debris by water in the general, the objective of this program,is to assess the containment or cavity. It should be noted that debris effects of scale on DCH phenomena. This was quenching by water willlead to vaporization and the accomplished by performing integral and counterpart 1
I INTRODUCTION experiments in two different facilities. Experiments IET-9 through SNL-IET-1!) indicated that hydrogen at 1/40th linear scale were conducted at Argonne combustion could be supported in an atmosphere National Laboratory and at 1/10th linear scale at approximately 50% inerted by steam. The ANL tests Sandia National Laboratories. The more specific have addressed questions regarding the debris objective of the counterpart testing is to obtain sweepout process from the cavity. Cavity gas integral effects data from scaled experiments with composition and temperature measurements indicate initial conditions related to specific postulated that the blowdown gasses and the melt nearly accident scenarios. The experiments incorporate melt chemically, and thermally equilibrate, during the ejection from the vessel, high pressure blowdown of cavity sweepout. It was found that this process alone primary system, entrainment and sweepout of debris significantly determines the measured pressure from the cavity, transport and trapping in the lower response of the containment. The last three tests of containment subcompartments, oxidation of metallic the ANL experiment program addressed the use of constituents, combustion of hydrogen, and heat the non-prototypic iron / alumina with chromium melt transfer to, and vaporization of, water in the used in the earlier ANL tests and the SNL tests.
containment.
The experiments employed the These used a prototypic core melt produced by a geometry of the Zion Nuclear Power Plant (NPP).
thermite type reaction. The melt closely matches the anticipated core melt for the NPP (Levy,1991). It is This report presents the results of the ANL shown that the prototypic material contains less experiments.
The specific objective of the specific thermal energy and higher chemical energy experiments reported on here is to conduct integral content. However, the results obtained in the corium DCH tests applying the SNL scaling methodology tests did not show significant differences in the DCH using a 1/4tn scale mockup of the SNL 1/10th scale load with respect to the tests with iron / alumina facility. Useful tests, counterpart to the SNL tests, simulant.
have been ensured by employing linear geometric scaling to the greatest extent feasible. The facility includes models of the vessel lower head, cavity, subcompartments and containment dome. In addition operating conditions were matched to the greatest extent possible to minimize sources of difference in the results, other than the scale distortions.
Measurements in the tests are made of the primary system pressure history, the cavity and containment pressure responses, gas temperatures, debris disposition, hydrogen production and oxygen depletion.
The integral tests at ANL have addressed
)
several questions. The first and most imponant relates to the effect of experiment scale on DCH phenornena. Comparison of test results betw een ANL and SNL indicated little effect of scale on the containment load. The ANL tests also addressed the question of whether steam in the containment atmosphere will inert hydrogen combustion. Two tests were run comparing 50% inerting of air try nitrogen or steam in the containment. The results indicated that at the 1/40th scale these experiments were conducted at the steam was effective in inerting the hydrogen combustion while the nitrogen was not.
However, further testing at larger scale at SNL (SNL-j NUREG/CR-6168 2
i i
2 E.D'ERIMENT DESCRIPTION i
2 EXPERIMENT DESCRIPTION The facility and test apparatus used in the test apparatus is described in detail in the next integral tests is described in this section. The section.
experiment was conducted in the Cotium E.K-Vessel Interaction (COREXIT) facility. The overall layout 2.2 Apparatus Description of the facility is shown schematically in Figure 2.1.
Major components of the facility include an explosion 2.2.1 Zion Cavity Model
.i resistant containment cell, a 1.51 m' expansion vessel, Zion Nuclear Power Plant (NPP) cavity and The cavity model was copied from an subcompartment models, and a high pressure steam origmal design by SNL. A 1/40 linear scale replicate system. The dimensions of the apparatus are based was designed and built for the ANL tests. It is on a 1/40th scale linear mockup of the Zion lower shown schematically in Figure 2.2. The cavity model containment structures.
All of the essential was designed to withstand pressures up to 4000 psi components of the tests apparatus are replicates of the produced by fuel coolant interactions. The model SNL 1/10th scale apparatus to the greatest extent consists of a concrete instrument tunnel and keyway feasible. Any inconsistencies that existed will be contained with an outer pipe pressure boundary. The described below.
tunnel and keyway are made up of the type of limestone / common sand concrete used at the Zion Details of the facility, test apparatus, NPP. Bolted on top of the pipe body is a saddle diagnostics, core melt simulant and procedures are piece, referred to as the top cap, which contains the given in the following sections.
melt generator and injector (MGI). The details of the inside of the MGI are shown in Figure 2.3.
This 2.1 FacilitV Description figure indicates the presence ofinternal heaters in the MGl. These heaters were used only in the U series The containment cell depicted schematically of tests.
in Figure 2.1 was constructed for performing ex-vessel severe accident experiments with reactor The melt generator intemals is made up of a materials. The facility was designed to contain a the reaction crucible and volume reducers. He fuel-coolant interaction with an equivalent energy thermite powders are contained within a ceramic release of 0.4 lbm of TNT. Further details on the "LAVITE" cmcible machined into a hemispherical containment is given by Spencer et al (1987). The shape. The inside radius is scaled to the Zion vessel expansion vessel protrudes through a circular opening lower head inner radius.
There is a hole of in the cell ceiling. The expansion vessel has an predetermined size drilled into the center of the inside diameter of 0.76 m and an overall height of hemisphere. Below the hemisphere is a steel orifice 3.1 m. The vessel has a total inside volume of 1.71 that contains a hollowed out brass plug. After m', however, this volume was reduced to 1.51 m' to ignition of the thermite the molten material is ejected match the SNL facility. This scales to 91,000 m' at into the cavity by melting out this brass plug. The full scale which is 18.3% over sized compared to the hole through which the melt is expelled is limited in actual 77,000 m' freeboard volume inside the Zion size by the hole in the "LAVITE*.
containment. He vessel has four sections containing various ports for instrumentation. The lower section In order to accommodate the MGI under the is a blind flange upon which the subcompartment vessel lower flange the cavity keyway is extended by model rests. This expansion vessel is raised up on a tunnel extension which mates the cavity to the EV.
legs in order to accommodate the cavity model This results in an elongation of the keyway by 1.7 underneath. Also located inside the cell is the reactor times its correctly scaled length. This distortion is coolant system (RCS) mockup volume. The volume the same in the SNL facility. Figure 2.4 is a is supplied steam by lines coming from the boiler schematic of the cavity internal surface dimensions.
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Tunnel Length 8.81 22.47 C
Tunnel Height 3.13 7.98 D
Keyway Length 6.19 15.79 E
Keyway Extension 31.0 F
Cavity Radius 2.60 6.63 O
Keyway x section 2.29 5.84 H
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Figure 2.4 Internal Cavity Dimensions
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2 EXPERIMENT DESCRIPTION 2.2.2 Subcompartment Model instrumentation that was used in the tests. The locations of various measurements are shown on the in order to address the affect of debris preceding figures. Further details are given below.
trapping in the containment a model of the Zion lower compartment structures was placed in the 23.1 Pressure Measurements expansion vessel. The model is shown schematically in Figures 2.5 and 2.6.
The location of the cavity All pressure measurements were made with exit is shown in die figures. The model is a scaled strain gauge type transducers. All of the transducers down version of the 1/10 scale model originally were calibrated using methods and dead weight j
conceived and built by SNL. The model does not testers traceable to NBS standards. The pressure i
include all of the complicated piping present in the measurements that are recorded during the tests are reactor containment building. However, the major listed below:
j flow paths and restrictiou are modeled. The model J
includes representations of the steam generators, a)
Accumulator Pressure History reactor coolant pumps, biological shield wall, b)
Melt Generator History j
refueling canal, and seal table room located above the c)
Cavity Pressure History i
cavity exit. The perimeter of the model is defined by d)
Expansion Vessel Pressure History a concrete circular wall which corresponds to the crane wallin the reactor. The model was constructed 23.2 Temperature Measurements from concrete and mortar. The components were painted with a white epoxy paint. The walls and 2.3.2.1 Subcompartment and Espansion Vessel floors are held together by threaded rods. Seals are Temperature Measurement made at various joints with high temperature silicon rubber.
Temperature measurements were made with bare junction type K (30 gauge) thermocouples at 2.23 Steam Delivery System various locations in the subcompartment model and expansion vessel.
The steam delivery system for the experiment is depicted schematically in Figure 2.1.
2.3.2.2 Casity Gas Temperature Measurement The system is made up of a high pressure steam boiler, the accumulator, a fast acting valve, the The temperature of the blowdown gasses injector and associated piping. The 25 gallon boiler exiting the cavity were measured with an aspirated can deliver saturated steam to pressures up to 10.3 thermocouple assembly. The assembly is depicted MPa. The accumulator is the mock up of the primary schematically in Figure 2.7. The assembly consists system volume and delivers the steam to the injector of a bare junction Type C thermocouple shielded by when the fast acting valve is opened.
The a 0.635 cm stainless steel tube. The tube has slot cut accumulator is heated by high temperature band in the end to draw gas through and over the heaters and is well insulated. The total unoccupied thennocouple.
The flow area through the slot volume up and down stream of the steam valve was matches the tube cross-sectional area.
The scaled to the Zion NPP primary system volume. This thermocouple junction is set back from the beads.
volurne is approximately 6.1 x IO'S m which scales The tube is inserted into the cavity near the end of 2
to 368 m' at full scale compared to 360 m' for the the instrument tunnel. The end of the tube extends Zion NPP. The ANL steam volume is over scaled 2.54 cm into the cavity. The slot is positioned to compared to the 0.3 m' volume at the 1/10 scale SNL face downstream of the flow. The opposite end of facility which scales to 300 m' at the NPP scale.
the tube is connected to a solenoid valve and evacuated gas sample bottle. When the valve is 2.3 Diaenostics crened gas is drawn from the cavity through the tube, and over the junction to the fill bottle. This allows a measurement of the gas temperature without Table 2.1 details the type and location of NUREG/CR-6168 g
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2 i'XPERIMENT DESCRIPTION Table 2.1 Instrumentation ID TYPE LOCATION PURPOSE TC8-16 TC-Type K Accumulator (RCS)
Steam Temperature TC8-17 TC-Type K Accumulator (RCS)
Steam Temperature PTS-1 PT 0-10.3 MPa Accumulator (RCS)
Steam Pressure PTS-2 PT 0-10.3 MPa Accumulator (RCS)
Steam Pressure UBW Burn Wire MOI Indicator to Open Valve PTS-3 PT 0-10.3 MPa MGI Driving Steam Pressure PTS-4 PT 0-10.3 MPa MGl Driving Steam Pressure PTS-5 PT 0-0.687 MPa Cavity Cavity Pressure PTS-6 PT 0-3.436 MPa Cavity Cavity Pressure PC Photocell Cavity Window Measure Debris Ejection Interval TC8-18 TC-Type K Seal Table Room Gas Temperature VS Microswitch Steam Delivery Valve Valve in Full Open Position TC8-7 TC Type K Subcompartment Gas Temperature TC8-8 TC Type K Subcompartment Gas Temperature TC8-9 TC Type K Subcompartment Gas Temperature TC8-10 TC Type K Subcompartment Gas Temperature PTS-10 PT 0-0.687 MPa Expansion Vessel Dome Containment Pressure PTS-Il PT 0-0.687 MPa Expansion Vessel Dome Containment Pressure PTS-12 PT 0-0.687 MPa Expansion Vessel Dome Containment Pressure TC8-20 TC Type K Refueling Canal Gas Temperature TCl2-1 TC Type K Expansion Vessel Dome Gas Temperature TCl2-2 TC Type K Expansion Vessel Dome Gas Temperature TCl2-3 TC Type K Expansion Vessel Dome Gas Temperature TCl2-4 TC Type K Expansion Vessel Dome Gas Temperature TCl2-5 TC Type K Expansion Vessel Dome Gas Temperature TCl2-6 TC Type K Expansion Vessel Dome Gas Temperature TCW-1 TC Type C Aspirated TC Assembly Cavity Gas Temperature NUREG/CR-6168 12
2 EXPERIMENT DESCRIPTION the junction encountering molten material.
23.6 Debris Disposition Measurements The temperature measured by the thermocouple will in general differ from the actual The disposition of the dispersed melt was temperature of the gas in the cavity. This error measured after the test. The recovery of the debris results from a number of sources as listed here:
was made by vacuuming each specific location of interest. The debris collected from each location was
- 1. Velocity error.
then weighed.
When it was assumed to be
- 2. Radiation error.
meaningful, a particle size analysis was carried out
- 3. Time response error, with a sonic sifter.
- 4. Conduction error.
Corrections for these errors was made by a procedure outlined by Moffatt (1962). The velocity of the flow Pressure transducer, thennocouple and other at the junction used for the velocity error correction signals of interest were routed from the test cell to was calculated by assuming compressible choked the data acquisition equipment. All signals were flow in the tube. Frictional losses were accounted for amplified and recorded by a Metrum RSR 512 rotary following White (1974). The maximum correction data recorder. The signals were recorded at a rate of was less than five percent from the raw measurement.
40 kHz per channel and stored on 1/2" video cassette tape. After the test the data was down loaded to an 233 Melt Ejection Indication IBM PC for reduction and analysis.
An indication of the start of the HPME was 2.4 Test Procedures and given by a burn wire located below the melt plug.
Operations The burn wire assembly consists of two varnished copper wires twisted together. When melt strikes the twisted pair, the varnish is vaporized, making an 2.4.1 Pretest electrical contact. A similar twisted pair is also located in the MOI above the melt plug which is used The pretest procedures specify the assembly to give the signal to open the valve. Both of these of the apparatus, loading of the thermite powders and burn wire assemblies are indicated in Figure 2.3.
the check out of the instrumentation.
The subcompartment is assembled and instrumented on 2.3.4 Visualization top of the lower flange of the expansion vessel. This is followed by the assembly and instrumentation of A video camera was placed at the top of the the expansion vessel. The thermite powder is mixed expansion vessel and was focused onto the in a glove box, transported to the test cell, and then subcompartment model.
This camera captured loaded into the MGl. 'lhe MGl is closed up and then images of the melt ejection from the subcompartment the cavity model is put into place under the and also gave visual confirmation of bydrogen burns expansion vessel. The last step in the assembly is when they occurred.
making the piping connections for the steam system.
The fmal pretest operation is the check out of the 2.3.5 Gas Cotnposition Measurements instrumentation and data acquisitico system.
Gas composition measurements were made 2.4.2. Test by taking grab samples at various locations and times during the test.
Samples were taken by filling Test operations are begun by preheating all initially evacuated 75 mi sample bottles. The samples of the piping and fittings associated with the steam are analyzed post-test by gas spectroscopy.
delivery system. This includes the accumulator, steam valve and MGl. In addition, if called for by the test, the EV is also heated. The accumulator is 13 NUREG/CR-6168
~
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l 2 EXPERIMENTDESCRIPTION I
heated to 600 K. The MGl is heated to 550 K. The the same mixture used in the SNL IET tests. In the MGl was heated to reduce problems with U series of tests a prototypic core melt was generated condensation after the steam is introduced by the via a thermite type reaction. In this section the j
main valve opening. However, temperatures in anticipated reactor core melt composition is i
excess of 400 K was found to cause spontaneous discussed. This is followed by a summary of the reaction of the uranium powders in the prototypic experiment simulants. Lastly, differences in the melts material tests. Problems associated with this are and the scaling considerations used to specify the discussed in the results. In parallel with the heating, initial melt mass are given.
[
the expansion vessel atmosphere is brought to its specified initial condition, and the steam boiler is 2.5.1 Prototype Core Melt Composition brought to operating conditions. When the apparatus f
is at the specified temperature, the water is added to The anticipated prototype core melt l
the cavity. The doors on the cell are then closed. At composition is assumed from the analysis of this point, the accumulator is pressurized with steam Levy (1991). Levy synthesized the predicted core l
from the boiler. When the accumulator is at the test melt progression of available code s.nalyses for a specification, the test is ready be initiated station blackout accident at the Surry Nuclear Power
[
Plant. An mstrument tube penetration failure is The test is begun by starting the data assumed to start the high pressure melt ejection. For i
acquisition and then depressing the ignition switch.
this scenario Levy estimated that a total of 44 metric i
l The ignition switch applies power to the ignitor tons of molten material would be available for assembly which starts the thermite reaction. The ejection. The composition of the molten materialis reaction proceeds downward in the MGI until it shown in Table 2.2. Levy calculated that this scales encounters the upper burn wire located above the to 54 MT for the Zion plant. In order to have a plug. The signal from the burn wire actuates the bound on the total amount of metallic zirconium the i
opening of the steam valve. Steam is applied to the 11,130 kg of U - Zr - O eutectic was broken down as j
MGl. This is followed by the failure of the brass follows. it is assumed that all of the uranium melt plug starting the HPME. Typically 0.2 to 0.5 originated as UO,.
This is subtracted from the seconds elapses between pressurization and the start eutectic, leaving Zr and some oxygen, it is assumed of the HPME. The HPhG is detected by the burn that the remaining oxygen had reacted with Zr to wire located under the brass plug. This signal produce ZrO,. What remains then is metallic Zr.
actuates timers which control the automatic gas Thus, the eutectic is assumed to be made up of 46.5 i
sampling. After the ejection, gas samples are also mass % UO,40.2 mass % ZrO,, and 13.3 mass % Zr.
3 l
taken manually at specified times. Data acquisition The stainless steelis assumed composed of 74 mass %
continues until all of the gas samples are taken.
Fe,18 mass % Cr and 8 mass % Ni. The assumed composition of the prototype core melt, broken down 2.4.3 Posttest into its fundamental oxide and metallic constituents, is shown in Table 2.3.
Posttest operations consist of the debris disposition m e a sur e rn e nt s, photographic 2.5.2 Experiment Simulants documentation of the posttest condition and particle i
sizing. In addition, the gas samples are analyzed by The best available method for generating the Analytical Chemistry division at ANL.
melts for DCH experiments is through thermite type reactions. The two types of melts that were used in 2.5 Core Melt Simulant the experiments are discussed in detail below.
Characterization 2.5.2.1 Irontalumina Thermite with Chromium Two types of core melt simulants were used g
- g in the experiments. In the IET series an iron /alumma i
has been used extensively m. reactor safety thite with additional chromium was used. This is i
NUREG/CR-6168 14 i
l
2 EXPERIMENT DESCRIPTION Table 2.2 Synthesized Molten Melt Composition for an Instrument Tube Penetration Failure at Surry from Levy (1991).
l Composition l
Mass, kg l
Steel 8,97C Zr 4,790 UO 18930 2
ZrO 0
2 U-Zr-O 11,130 i
Total 43.820 Table 2.3 Summary of core melt and simulant compositions (mass fraction).
SASM Fe/Al O w/Cr Experiment Corium 2 3 UO 0.550 0.0 0.578 2
Zr 0.143 0.0 0.137
- Zro, 0.102 0.0 0.105 Fe 0.152 0.505 0.143 Cr 0.0369 0.108 0.0371 Ni 0.0164 0.0 0.0 Al O 0.0 0.373 0.0 2 3 Al 0.0 0.0139 0.0 experiments. The simulant used in the IET test series aluminum in the melt. The same powders used in the was originally developed by Allen et al (1991) for the SNL tests were obtained for use in the ANL Limited Flight Path (LFP) DCII experiment series at experiments. The chemical equation describing the SNL. In these experiments chromium was added to thermite reaction is given by (Allen et al,1991),
the initial mixture of iron oxide and aluminum powders for two reasons; (1) to cool the mixture to more prototypic temperatures, and (2) to make the oxidation potential of the melt more prototypic. The composition used in the LFP tests was also used in 1
the IET tests. Due to non-uniformities in the iron oxide powders used at SNL the thermite reaction was i
not stoichiometric. This resulted in a small excess of 15 NUREG/CR-6168 i
2 EXPERIMENT DESCRIPTION
\\
91.1 IFe,0,
+ 165.73FeO 6.39Fe,0 103.95Cr 391.94A1
+
+
+
3 3) 183.llAl 0,
+ 451.84Fe 25.72Al + 103.95Cr
+
2 This reaction resulted in a molten mixture at In practice this temperature will not be realized due approximately 2500 K. The composition is given in to several limiting heat transfer and thermodynamic Table 2.3.
factors. The following two are the most important.
First, the reaction crucible is not a true adiabatic container and there will be heat losses to the 2.5.2.2 Erperimental Corium surrounding structure. Secondly,the temperature will be limited by the boiling points of the metal Several options were considered for a constituents. The boiling temperatures for Cr and Fe potential prototypic experiment corium composition are 2945 K and 3080 K, respectively. Thus, energy generated by a thermitic reaction. Development must go into vaporizing these constituents to rise to testing was carried out in order to verify the viability the adiabatic temperature.
of a possible composition. A development test consisted of mixing powders of the proposed Figure 2.8 shows the temperatures measured compositions in the MGI crucible and then igniting by the tantalum sheathed Type C thermocouples the mixture with a nichrome wire.
A viable located in the melt in the two development tests. The candidate was found if the reaction was self-thermocouples measured peak temperatures in the sustaining, the mixture became fully molten and range from 2600 to 2750 K. Figure 2.9 shows the exhibited good flow properties. Temperature of the temperature measured by a pyrometer focused on the melt was measured in two ways. First, there were melt stream exiting the crucible. The data obtained tantalum sheathed Type C thermocouples located in by the pyrometer shows a considerable amount of the MGl. Secondly, two pyrometers were focused on noise. The source of this noise is the large amount of the melt stream exiting the injector.
aerosol surrounding the melt stream, partially obscuring it, and producing the unclean signal. The From the development testing a thermite type data was smoothed numerically by successively reaction which produced an excellent prototypic melt applying an eleven point smoothing algorithm until a was identified. The reaction is given by, satisfactory result was obtained. The smoothed data is also shown on the figures The smooth signals i
10.5Zr 15U + 6Zr +
9Fe,0
+ SCrO,
+
3 (2-2)
+ 18Fe + SCr + 10.5Zr +
1.87MJ/kg 15UO, + 6ZrO, Two tests were run with this same composition to show temperature peaks at approximately 2800 K.
check for reproducible behavior. The approximate From this data it is concluded that the melt obtains a composition of the experiment melt is shown in Table temperature in the range of 2600 to 2800 K, with 2.3. Close approximation of the prototype is noted.
2700 K being the recommended value.
The simulant used in the IET tests is given for comparison.
The actual melt composition formed by the reaction will not match the right hand side of The temperature of the melt after complete equation (2-1) or the composition given in Table 2.4.
reaction will depend upon several factors. An upper The following discussion is adapted from the work of bound can be estimated by assuming that the reaction Baker (1993).
The melt will consist of two takes place adiabatically. The heats of formation of immiscible compositions, a metal and an oxide. The the reactants and products together with the enthalpy metal will consist of mostly zirconium with sotne data yields a temperature of 3280 K (Baker,1993).
uranium. In addition there is substantial solubility of NUREG/CR-6168 16
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Figure 2.8 Coriums Simulant Temperature Measured with Type C T'nermecouples k
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2 EXPERibiENTDESCRIPTION oxygen in a zirconium-uranium liquid, metallic phase.
degrees of superheat in the alumina, iron and If the materials reach en equilibrium the oxide will be chromium, respectively. The superheat in the iron is in the form (U,Zr)Ou It is generally assumed that important because it comprises 50.5% of the mass of i
the steel, i.e. iron and chromium, will be miscible the melt. At the corium simulant temperature of with the zirconium melt. There are two significant 2700 K the enthalpy is 1.2 MJ/kg. The amount of effects of this type of equilibration. The first is to superheat is dif5 cult to determine because of the decrease the differences in density between the two uncertainties in the melt form. However, the amount phases. This is partially evidenced by examining the of superheat in the oxide is expected to be small.
melt composition obtained in the development tests.
The oxide phase accounts for approximately 65% of Microscope examination showed that the phases were the mass. Because of this, freezing effects can intimately mixed, indicating that segregation of the provide a significant limitation to melt entrainment phases did not occur before solidification. This is in and ultimately to the transfer of heat from the melt to contrast to the iron /alumma mixture in which the the containment atmosphere.
metal and oxide phases rapidly separates due to the large density difference.
It is also likely that A second important difference between the difference in surface tension is decreased. A second simulants is their oxidation potential. A significant effect of this equilibration is to leave the oxide, as fraction of the iron / alumina thermite is made up of well as the metal, deficient in oxygen. Therefore, the metal, which is predominantly iron. The iron is a oxide could later react with the steam during the weak oxidizer, with steam, when compared to DCII process. The individual heats of reaction are zirconium, chromium and aluminum.
By weak not well known.
oxidizer it is meant that the Gibbs free energy for reaction is relatively low. Thus, the other metals will The above discussion was given only to preferentially react with the steam. The heat of suggest the possible form of the melt.
The reaction is also small for iron and steam compared to determination of the exact composition would require the other metals reaction with steam. These reasons a detailed phase and chemical characterization of the provided the motivation for adding chromium to the end product. However, this type of study would be iron / alumina thermite mixture. In contrast corium difficult due to the close mixing of the phases. The simulant contains significantly less metal, by mass study would require careful separation of the phases, fraction, compared to the iron / alumina simulant.
characterization by X-ray diffraction, foll owed by an However, the fraction which is a strong oxidizer is elemental and oxygen content analysis. This detailed larger. These differences can be noted in Table 2.4 chemical analysis was not possible.
below. From the data it is noted that the specific oxidation energy is the same for the two melts.
2.5.3 Scaling Considerations However, for the case of the corium, a larger percentage, 88.0%,
will come from exothermic The scaling criteria for selecting the test metals as compared to $6.4% for the iron / alumina initial melt mass will be established. For purposes of thermite.
In addition, the potential exists for making comparisons and establishing the scaling producing over twice as many moles of hydrogen criteria the composition of the prototypic experiment with the iron /alumma thermite. However,if only the melt will be assumed to be given by the right hand strongly exothermic metals are considered,the corium side of equation 21. This is equivalent to the mass could potentially produce 18.0% more hydrogen than fraction given in Table 2.3.
the iron /alumma thermite.
Figure 2.10 plots the prototype and simulant Energy to volume scaling has been used to melt enthalpy as a function of temperature. It is clear specify the initial melt mass for the experiments that the iron / alumina melt contains significantly more (Pilch,1991). The objective is to match the ratio of thermal energy. At the iron / alumina melt temperature, the total possible energy input to the containment 2500 K, the enthalpy is 2.65 MJ/kg. At this volume in the experiment to the reactor case. This is temperature there is approximately 200,700 and 370 equivalent to matching the maximum theoretical containment pressure increase, APax, normalized by 19 NUREG/CR-6168
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=
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Corium Simulant x
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0 1000 2000 3000 Temperature, K Figure 2.10 Melt Spec;fic Enthalpy
, ~ _,.
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2 EXPERIMENT DESCRIPTION Table 2.4 Oxidation Characteristics of Melt Simulants with Steam Contributor g-moles of H, g-moles of H Energy Energy Released 2
Produced per Produced per Released per per Mass Oxidized Mass Oxidized Mass Oxidized Mass Oxidized Fe/A10 w/Cr Corium Fe/Al O w/Cr Corium 2 3 2 3 h0/kg hU/kg Zr 0
3.00 0.0 0.88 Cr 3.11 1.07 0.45 0.16 Al 0.39 0.0 0.21 0.0 Total of 3.50 4.07 0.66 1.04 Exothermies Fe 12.0 3.40 0.51 0.14 Total 15.5 7.47 1.17 1.18 the initial containment pressure, Pg, at reactor and experiment scale. Following developments given by AE = AE, + E, + AEox + AE,, + AE,, (2-5)
Pilch (1991) the dimensionless ratio is given by, The source due to the blowdown gasses is given by
= =.
y-1 AE(M,)
(2-3)
P"C'#V"C5 Pd (2-6)
P, 1 + $(M,) P V, AE,=
1-g YRCS_
RCI.0 g
j where P,cs, is the initial pressure of the reactor j
where y is the heat capacity ratio of the containment coolant system (RCS), Vac, is the volume of the RCS gasses, Po is the containment initial pressure, and M, and yac3 is the specific heat ratio of the blowdown is the participating debris mass. The ratio of the gasses. The source due to the debris thermal energy debris heat capacity to the total heat espacity of the is given by containment gasses is given by
)
AE,= M, Ae,,
(27)
M,C' (2-4) 9- (N + N,)C, where Ae is the specific enthalpy of the debris at its g
r initial temperature. The source due to oxidation of j
the metallic constituents in the debris will be limited by either the debris mass or the available steam and where C,is the heat capacity of the debris, No is the is given by the following for each case, initial number of gas moles in the containment, N, is 1
the number of blowdown gas moles and C, is the j
effective constant volume specific of the containment gasses. The total energy available for pressurizing the containment. AE, is primarily a function of the debris mass and is given by 21 NUREG/CR-6168
2 EXPERIMENT DESCRIPI70N AE,= [yC,,p,,7(P,) - C,,,p(T,,7(P,)
T y
y 3
-T,)-hyp]M,p M, [ fo'x%'Ac 'x for M {
sN o
s where hp2o is the heat of vaporization of the water.
's AE d in developing this expression for the maximu:n ox p ssible containment pressure load the following
{ a' Ac 'x for M, { MW
>N, a
asunptions were made:
s, (2-8) 1)
The containment volume is considered a where fox' is the fraction oxidized, x' is the mass single cell.
fraction, Aeox'is the specific reaction energy, and v 2)
All of the participating debris contributes as 3
is the stoichiometric coefficient for oxidation of the fragmented particles and equilibrate with the i* species. For the case of steam limited oxidation containment atmosphere.
the coefficients, a,, give the mass of the i* species 3)
Heat loss to structure is ignored.
oxidized. The oxidation of the metallic species is assumed to occur preferentially, i.e. the species with The dimensionless adiabatic pressure the highest Gibbs free energy reacts first, followed by increase, equation (2 3), has been calculated for the j
the second, third, etc., until all of the steam is reactor case and the experiments. The results are consumed.
The number of moles of hydrogen presented in Figures 2.11 through 2,13. The total available for combustion are present from pre-existing load and the contributions from each of the four hydrogen and the metal-steam reactions and is given major contributors (RCS blowdown, debris thermal j
by energy. debris oxidation. and hydrocen combustion)
J M, { MW,
+ f,'N,, for M, { v.foxI sN, fo'xf MW A,
i, (2-9)
N,' => '
N, + f,N,, for M, { v,fo'x%'>N, u
t i
where f,2 is the fraction of the initial containment are plotted as a function of participating debris mass.
gasses that is hydrogen. The source due to the The initial conditions that were assumed to make combustion of hydrogen will depend on the these calculations are given in Table 2.5.
The availability of oxygen and is given by experiment values are given in full scale and at experiments scale for comparison. In making these N,
calculations the following assumptions were made.
N,*MW 4c,' for f,N 2_-
l u,
o g 2
(2-10) l AE,,
N 1)
All of the water in the cavity was completely i
n 2f,N,,MW,p,, kr f,N,,<
vaporized by the melt.
o o
2)
All of the melt is oxidized to the extent that steam is available.
3)
All hydrogen, pre-existing and produced, is i
where Ae,2 is the specific heat of combustion for burned to the extent that oxygen is hydrogen. The net effect of the vaporization of a available.
mass, M,20, of water in the containment is given by The containment atmospheres were assumed to be the same for the reactor and experiment. The number of NUREG/CR-6168 22 u..
i l
l 10 9
Blowdown & Vaporization Thermal 8
Hydrogen Combustion
~
Oxidation 7
tal lo 6
5 u
tea 4
3 2
--.-:--=
1 0.,e c r g..--:
u
..,........,........,....,....,....,....,....,....,....,...,....,....p...s....
0 20000 40000 60000 80000 100000 Melt Mass, kg b
.Oh
- c 5
Figure 2.11 Scaling Melt Mass Calculation for the Zion NPP
g o
k' a
- =
ti s
3:
=
e 10 Q
9 Blowdown & Vaporization
--- Thermal 8 - ------- Hydro en Combustion
~
0xida ion
==
7 Total 6
5
~
A 4
~~..... ---~~~--........ -
3 2
~
- ~ _ _........-.-
1 g
.m. _ _ v w.=__.- r,...........................................,.............
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
=1.0 Melt Mcss, kg Figure 2.12 Scaling Melt Mass Calculatten for the Esperiment with Iron-Alumina Thernaite 1
10 9
Blowdown & Vaporization Thermal 8
Hydrogen Combustion
~
~
Oxidation 7
Total 6
5 u
4 3
W-
'p 2- '
ww",,.,,=
.. * :}
1...,,,.r..., Td*... c=..c==== =
~~.'~,.......
3....,....,...
...,.........r.......,....,....p...s....,....,...-
u 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 m
Melt Mass, kg b
tri 0
en:c&
j Figure 2.13 Scaling Melt Mass Calculation for the Experiment with Corium f
=
s
~
.r
2 EXPERIMENT DESCRIPTION Table 2.5 Assumeil Initial Conditions Used in Melt Mass Scaling Calculations Zion NPP Experiment (2.55%)
Experiment (Full Scale)
V,,m' 77,000 1.51 89,800 Vaa, m' 360 6.1 x 10'8 368 P MPa 0.2 0.2 0.2 T,K 373 373 373 o
Atmosphere, mol%
Air 50 50 50 Steam 46 46 46 Hydrogen 4
4 4
Steam g-moles in RCS 545,000 9.0 543,000 Cavity Water, g-moles 144,000 3.0 180,930 Table 2.6 Required Melt Mass to Satisfy Energy / Volume Scaling AP/Po Mass (kg) i SASM-NPP 5.84 54,000 Fe-Al O w/Cr 5.84 0.71 2 3 Experimental Corium 5.84 1.13 Table 2.7 Fractional Contribution to DCH Maximum Load SASM-NPP Fe-Al O w/Cr Experimental Corium 2 3 Blowdown 0.0267 0.0228 0.0243 Thermal 0.211 0.254 0.232 Oxidation 0.246 0.147 0.249 H,
0.516 0.576 0.495 j
i 2 EXPERIMENTDESCRIPTION moles of cavity water were taken from the scaling study of Pilch for the reactor. The initial temperature of the NPP melt was taken as 2500 K following Lesy (1991).
The temperature for the iron-alumina simulant was assumed to be 2500 K. Temperature for the corium simulant was taken as 2700 K.
An energy to volume ratio of 5.84 was calculated for 54,000 kg molten melt ejected at Zion.
This is used to estimate the initial melt mass for the simulant experiments. The results are shown in Table 2.6. Table 2.7 shows the fractional contributions of each of the DCH contributors at an energy to volume ratio of 5.84.
6 27 NUREG/CR-6168 l
l
O
~._ - - - - - __ _ _ _ _
a I
f) i :.
I-3 EXPERlhiENTRESULT5 3
EXPERIMENT RESULTS The results from the 1/40 scale DCH integral 3.2 Test Initial and Boundarv
[
tests are described in this section. The initial series Conditions p
of tests was denoted the Integral Effects Tests (IET).
These tests employed iron / alumina thermite with chromium as a core melt simulant. Seven tests were 3.2.1 Selection of the NPP and Accident run in this series and are denoted ET - 1, IR, IRR, Sequence 3,6,7,8. The IET-1 and IR tests were scoping tests and are not described in this report. Following the The nuclear power plant under consideration ET test series the U series was conducted which is the Zion generating station. Attention was paid to used prototypic core materials in the melt simulant.
modeling th: reactor vessel lower head, reactor i
Three tests were run in this series, UlA, UlB and cavity, instrurnent tunnel and lower subcompartment '
U2. The tests were completed over a time period structures in some detail. The lower subcompartment from February,1992 to March,1993.
structures were included in order to capture the l
potential mitigating effects produced by debris 3.1 ObiectiveS -
trapping after it is swept from the cavity. Details on the experiment model were given in Section 2. The The main objective of the ET test series was accident sequence considered is a pump seal failure to investigate the effect of scale on DCH phenomena.
induced LOCA produced by a station blackout. The This has been accomplished by undertaking core melt progression and composition on the lower counterpart integral testing at 1/10 scale in the SNL head is assumed from the annlysis of Levy (1991).
facility and at 1/40 scale in the ANL facility. Three The vessel breach is assumed to occur by the failure tests at ANL were specifically counterpart to SNL of an instrument tube penetration. Table 3.1 gives a tests. These tests are ET-IRR,3, and 6, which are summary and comparison of the relevant initial and i
counterpart to SNL IET-1R (Allen et al,1992),IET-3 boundary conditions for the Zion NPP, the (Allen et al,1992) and ET-6 (Allen et al,1992),
experiment and the experiment at full scale. Table respectively.
The ANL-SNL counterpart tests 3.2 gives the actual initial conditions for all of the nominally varied only the length scale.
The experiments. Further details are given below.
I remaining tests, IET-7 and 8, addressed issues
(
regarding the containment initial conditions.
3.2.2 Hole Diameter i
l Upon completion of the IET test series a The initial breach size is assumed to be an second series of integral tests, the U series, was instrument tube penetration which is a hole initiated. These tests addressed issues regarding the approximately 2.54 cm in diameter. As the melt is use of nonprototypic iron / alumina thermite as a core ejected the hole will grow in size due to ablation of melt simulant. In these tests prototypic core melt was the lower head steel.
For the assumed initial generated via a thermite type reaction. Three tests conditions a final ablated hole diameter of 40 cm was were completed and are denoted as UIA, UlB and calculated. Simulation of this ablation behavior is U2. The UlB and U2 tests are counterpart to the not possible in a small scale experiment. Therefore, IET-lRR and IET-6 tests, respectively.
in the experiment, the hole size is fixed at the calculated final diameter scaled to the experiment In the next section the test initial and scale. This diameter is 1.1 cm. In the IET-IRR test boundary conditions are summarized.
This is the "LAVITE" limiter partially failed which resulted followed by a description of the test results.
in a final hole of 1.3 cm.
29 NUREG/CR-6168 l
l
3 EXPERIMENT RESULT 5 Table 3.1 Summary of Specified Reference Initial and Boundary Conditions Zion NPP 1/40 Scale Full Scale Melt Mass, kg 54,000 0.71 Fe-A10 45,000 Fe-A10 3 3 3 3 1.13 Corium 54,000 Corium Melt Temperature, K 2600 K 2500 K Fe-Al O 2500 K Fe-A1 0 2 3 3 3 2700 K Corium 2700 K Corium j
RPV Gas Composition Steam Steam Steam RPV Pressure, MPa 17.0(6.2')
6.2 6.2 Volume, m' 360.0 6.1 x 10 '2 368 Hole Diameter, em Initial 2.54 1.1 42.0 Final 35.0 Containment Free 77,000 1.51 89,800 Volume, m' Pressure, MPa 0.2 0.2 0.2 Composition, mol%
50% Air, Varied Varied
)
46.0% Steam, 4.0% Hydrogen 1
Temperature, K 373 300 300 Cavity Water, kg 2600 0.057 3480-Depth, em 6.7 0.23 15.0
' Pump Seal EGCA 3.2.3 Melt Mass 3.2.4 Driving Steam The initial mass of melt for the experiments The driving steam pressure was matched was established by the scaling analysis that is detailed between the NPP and the experiment. The initial in Section 2. The objective of this analysis was to driving pressure is obtained when the steam valve is match the ratio of the total energy input to opened and the accumulator and free volume in the containment volume between experiment and the MGl equilibrate prior to plug failure. In order to NPP. This analysis resulted in a mass of 0.71 kg for obtain the appropriate driving pressure (nominally 6.2 the iron / alumina thermite IET tests and 1.13 kg for MPa), the accumulator is set initially to a higher the corium tests. Concems with potential freezing pressure (nominally 8.9 MPa). The temperature of the effects limiting the mass of melt ejected lead to accumulator is initially 590 to 600 K. The primary higher initial thermite charge masses in IET-lRR and system volume given in Table 3.1 is the total of the 3.
These freezing effects were found to be accumulator volume and the free space in the MGl.
unimportant and the initial mass was set at 0.71 kg in the scoping tests, difficulties with steam for the remaining IET tests.
condensation were encountered when the steam valve was opened. In order to prevent this, the MGl intemals were heated to 550 K prior to the test. This was not possible in the corium tests because NUREG/CR-6168 30
3 EXPERIhiENTRESUL15 Table 3.2 Experiment Initial Conditions IET-1 RR IET-3 IET-6 IET-7 IET-R U1A U1B U2 Melt Fe/Al.0 Fe/Al,0, Fe/Al,O, Fe/Al,0 Fe/Al,0 Corium Corium Corium 3
3 3
Mass, kg 0.82 0.82 0.71 0.71 0.71 1.13 1.13 1.13 D. cm 1.3 1.1 1.1 1.1 1.1 1.1 1.1 1.1 P,,.,, MPa 6.7 5.7 6.6 6.1 6.5 3.0 6.0 4.3 N,, g-moles 9.84 8.43 9.65 8.88 9.36 4.18 8.87 5.89 Pm MPa 0.2 0.2 0.2 0.1 0.2 0.2 0.2 0.2 Ta, K 318 315 310 310 473 300 300 301 Atm., inol%
H, 0.0 0.0 2.0 0.0 3.9 0.0 0.0 2.6 O
0.I 10.8 9.9 10.1 7.7 0.6 0.5 11.6 2
Steam 0.0 0.0 0.0 0.0 49.0 0.0 0.0 0.0 N,
99 9 RR 8 87.5 89 4 37.4 99 0 99.0 84 6 temperatures in excess of 373 K caused spontaneous combustion loadings. The initial pressure for this test reaction of the uranium powders. This accounts for was 0.2 MPa.
t'.e lower driving pressures obtained in the corium i
tests. The number of moles of driving steam are 3.2.5.2 Containment Conditions for IET-3 calculated from the accumulator pressure and temperature conditions at the time the plugged failed.
The containment atmr.h re composition for This data is included in Table 3,2 this was selected in order tr. ahe,a te combustion of the hydrogen produced in the 7r'al/ steam reactions.
3.2.5 Containment Atmosphere The atmosphere initial compc sition was nominally 50 Conditions mol% air and 50 mol% nitrogen. Comparison of this test and the IET-IRR test gives a measure of the The containment atmosphere conditions e ntainment loading efficiency of the combustion of (pressure, temperature and composition) were the hydrogen produced by metal oxidation with steam.
main parameters varied in the tests. The conditions The initial pressure for this test was 0.2 MPa.
for each test is summarized below.
3.2.5.3 Containment Conditions for IET-6 3.2.5.1 Containment Conditions for IET-IRR The IET-6 test further incremented a change The containment was inerted with nitrogen in the initial containment atmosphere by adding pre-for these tests. Inerting the atmosphere suppresses existing hydrogen. This test when compared to the hydrogen combustion and allows direct measurement IET-3 and IET-lRR tests gave a measurement of the of the hydrogen produced by metal / steam reactions.
efficiency of containment loading due to combustion of Pre-existing hydrogen.
The nominal initial Therefore, the tests measure the efficiency of the metal oxidation by steam and of the debris / gas heat c mposition was 48.7 mol% nitrogen,48.7 mol% air, transfer. These tests provide a baseline for the and 2.6 mol% hydrogen. The amount of hydrogen is consistent with the in. vessel oxidation of 50 % of the subsequent tests which do not suppress hydrogen combustion. Direct comparison of inerted and non-zircaloy fuel element cladding and subsequent release inerted tests give an estimation of the hydrogen to the containment atmosphere. Consistent with the 31 NUREG/CR-6168
3 EXPERIMENT RESULIS i
previous tests the initial pressure was 0.2 MPa.
defined as the time at which the brass melt plug failed and the HPhE commenced.
3.2.5.4 Containment Conditions for IET 7 3.3.1 Primary System Blowdown The IET-7 test duplicated the cwtainment atmosphere composition oflET-3; however, the initial Figure 3.1 shows a typical pressure history pressure was decreased by one half to 0.1 MPa. The i2 the accumulator and MGl during a test. The traces objective of this test was to investigate the impact of show the accumulator at the pre-test initial pressure.
varying the ratio of the initial steam driving pressure Upon ignition of the thermite powders the pressure to initial containment pressure.
increases in the MGl due to heating of the gasses.
The reaction proceeds downward in the powders until 3.2.5.5 Containment Conditions for IET-8 the upper bum wire located above the brass plug (Figure 2.3) is contacted. This causes a signal to be The IET-8 test investigated the potential for sent to open the steam valve, which applies steam a prototypic containment atmosphere to inert the from the accumulator to the MGl. The time to fully combustion of hydrogen. A prototypic containment open the valve is on the order of 100 milliseconds.
atmosphere for this test was obtained by adding Shortly after the steam is applied the brass plug fails approximately one bar of steam to the containment and the HPME begins.
which contained initially one bar of air. In addition pre-existing hydrogen was also added. The initial Figure 3.2 gives a summary of the blowdown pressure was approximately 0.2 MPa.
histories obtained in the experiments. Analysis of these traces indicates that punch through of the melt 3.2.5.6 Containment Conditions for UI A and UlB pool in the MGl occurred immediately in all of the tests. Therefore, the initial blowdown of the system These corium tests were run counterpart to into the cavity is characterized by a two phase the IET-lRR test, therefore, the containment ejection of melt and steam. This two phase ejection atmosphere was initially inerted with nitrogen. The period occurred for approximately 0.2 seconds, at initial pressure was nominally 0.2 MPa.
which time the MGI is emptied of melt, and the single phase blowdown of steam continues until the 3.2.5.7 Containment Conditions for U2 primary system is fully vented. The time for the blowdown to be completed is on the order of one This corium test was counterpart to the IET.
second. The effect of this two-phase ejection is given 6 test and was specified with nominally the same in Figure 3.3 which plots instantaneous rate of change atmosphere conditions.
of steam moles in the primary system as function of time. The peak in the blowdown rate occurs when 3.2.6 Cavity Water the melt is completely ejected from the MGl. A blowdown time constant, r,, was obtained from the Water was added to the cavity prior to all of blowdown histories by fitting the data to the tests. The amount of water was dictated by the scaling analysis of Pilch (1992) to match the potential (3,3) p,p q mitigating effect due to debris quenching. However, this resulted in a very small amount of water in these small scale tests.
If the blowdown of the primary system occurs isothermally, then the blowdown time will be given 3.3 Test Results by, v,c, This section describes the results of the T.
(3-2)
=
integral tests. Table 3.3 gives a summary of the key C,A /RT,cs,,
4 test results. In all of the figures, time zero was NUREG/CR-6168 32 Em
l i
P i
[
10 9
Ac c umulator 8
7 O
Q.
s 6
O 5
O
'a i
m I
4 t
3 2
1 MGl g
Time, sec s 1.0 -0.8 -0.6 -0.4 -0.2 00 02 04 0.6 0.8 1.0 8
a r
- o M
r b
h Figure 3.1 Typical Blewdown Sequence Obtained in the Tests d
4 E
-o as n,
wrs ao 7
/
I i
I i
i j
i i
ks...'..
u
!s 6 +;.w s...,A U1 A r
xs
,,g U1 B 5
gc.h a.
\\; %x IET-1 RR g
U2 i
g, g%o-IET-7 IET-6
~
3 4 A
\\\\
%v. -Gg...
r E
's_
IET-8 m
g xx..
m 3
N s.~ -(t.
s 8
a_
t x x. x>t N
s.N.it s s, N
s 2
'x c.'s)%
s~
s
~- Q.
s, s
m
..i fw.,%,,,
"ss
_'N 1
% h-' A
,,,w%
I
- w Ni' "O s s.
~**1 s
MP'.r.y.rm~c.1.m,,y, r_
a:.
N w
e l
s l
t I
a l
t t
t t
t t
f N=% _
t r
0.0 0.1 0.2 0.3 0.4 0.5 0.6
-0.7 0.8 0.9-1.0 Time, sec Ms= n Pri-ry symem akmm-nise.*. obe ima in the rest.
3 i
22 20 18
~
h$
16 g
\\m 14
~
_D o
12
~
E m
i 10 CD S
8 s
c 6
n 4
~
~
~
2 0
g i
i l
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 5
O 4
g Time, sec g
h lE Figure 3.3 Rate of Change of Steam Moles in the Primary System y
3 EXPERIMENT RESULT 5 Table 3.3 Summary of Test Results ET-1RR ET-3 ET-6 ET-7 ET-8 U1A U1B U2 Driving Pressure, P,cs,, VPa 6.7 5.7 6.6 6.1 6.5 3.0 6.0 4.3 Blowdown Steam, g-moles 9.84 8.43 9.65 8.88 9.36 4.18 8.87 5.89 Melt Mass, kg 0.79 0.75 0.71 0.69 0.70 1.130 1.130 1.130 Initial Cont. Pressure, Peo,rr,, MPa 0.2 0.2 0.2 0.1 0.2 0.2 0.2 0.2 Blowdown Time Constant, t,, secs 0.23 0.41 0.28 0.32 0.33 0.38 0.54 0.49 Initial Containment Atmosphere Composition, mole %
H 0.0 0.0 2.0 0.0 3.9 0.0 0.0 2.6 2
0 0.1 10.8 9.9 10.1 7.7 0.6 0.5 11.6 3
Steam 0.0 0.0 0.0 0.0 49.0 0.0 0.0 0.0 N
99.9 j 88.8 87.5 89.4 37.4 99.0 99.0 84.6 2
APurx.c4vrry, kPa 550 200 480 430 290 90 400 185 APuxx.coirr, kPa 150 190 250 166 133 45 111 185 Sweepout Fraction 0.705 0.735 0.691 0.793 0.766 0.190 0.795 0.295 II: Pre-existing, g-moles 0
0 2.3 0
3.0 0
0 3.1 H Produced, g-moles 4.1 4.7 4.9 5.2 5.2 5.0 6.0 6.0 0 Depleted, g-moles
-0 1.8 2.1 1.8 0.4 4
4 3.0 2
where Vacs is the volume of the reactor coolant with the counterpart ET tests. Table 3.3 summarizes primary system, An is the area of the breach, R is the the peak pressure rise for all of the tests. The ideal gas constant, Tacs, is the initial temperature of maximum pressure rise was obtained in ET-6. This the blowdowri gas, and C, is a discharge coefficient.
is expected because this test contained pre-existing The blowdown time constants obtained from each test hydrogen.
Comparison of ET-IRR and ET-3 is summanzed in Table 3.3 indicates an increase from 150 kPa to 190 kPa due to hydrogen combustion. The addition of pre-existing 3.3.2 Pressure Measurements hydrogen to the containment in ET-6 further increased the peak pressure rise to 250 kPa.
3.3.2.1 Containment Loads L wering the initial containment pressure in ET-7 to 0.1 MPa resulted in peak pressure rise of 166 kPa Figure 3.4 gives the containment loads e mpared to 190 kPa for ET-3. In the ET-3,6,7 obtained in the ET tests and Figure 3.5 gives the and U2 tests a visible flame was present rising up containment loads obtained in the corium tests along from the operating deck during the HPME. This is NUREG/CR-6168 36
\\
l J. -
300 i
o 1ET-8 S
c IET-7 J
~
IET-6 m
O lET-3 8
lET-1 RR o
200 -
.E e
ay
~
- ^
"-+-*--m-.-
~
e
_.____ ~ __
^--
a-
's 100 -
e
_._+
E o
.53
~
C
~
O O
Q 0
i 0
3 2
3 4
5 E-m Time, secs g
4 O
a Figure 3,4 Containment Loads Obtained in the IET Tests
- i l!
,lll f'
I sN@*$ B:su 4
^
s 3
n t
e m
i re
~
p sE se u
l roC c
e h
e t
s se l
d 2
e e
i n
i m
a t
b
^
iT O
s da R
e R
L tn 8
A_
e 1
~
m 6
n 2
i I
4U-1 a
1-t T
U J
n E
J 1
eC 5
3 erug iF j
l '
0 0
0 0
0 0
0 0
0 5
4 3
2 0ax f M0u.a iOa55 M
l l
3 EVERSIENT RESULTS con 6rmation of the occurrence of hydrogen Figure 3.18. The high peak temperatures measured in combustion in these tests.
This result is also the cavity result from the large heat transfer rates that supported by the hydrogen measurements. The peak occurs between the entrained melt particles and the pressure rise in IET-8 was 133 kPa despite the blowdown gas during the cavity sweepout phase.
presence of pre-existing hydrogen. This indicates the suppression of hydrogen combustion by steam in the 3.3.3.2 Subcompartment Gas Temperatures atmosphere.
This is supported by the gas composition measurements presented in the next The temperatures measured at various section and the lack of detection of a flame by the locations in the subcompartment are plotted in vessel cameras. The containment loads obtained in Figures 3.19 through 3.26 for each test.
The the corium tests were consistently lower than the thermocouple locations can be obtained from Figure loads obtained in the iron / alumina thermite tests. The 2.6. In summary, TC8-7 and TC8-9 are on the cavity pressure rises in UI A and UlB were 45 and 111 kPa exit side and TCS-8 and TC8-10 are opposite the compared to 150 kPa in IET-lRR. The pressure rise cavity exit. TC8-18 is located in the seal table room.
in the U2 test was 185 kPa compared to 250 kPa in In all of the tests higher temperatures were measured IET-6. liowever, somewhat uncertain,is the effect of on the cavity exit side of the model.
Peak the lower driving pressure in U2. Despite these temperatures on the cavity side ranged from 1000 K uncertainties, there was not significant differences in so over 1530 K.
The maximum temperature that the containment loads measured in the counterpart could be measured by the Type K thermocouples that melt simulant tests.
were used is 1530 K. Measured temperatures on the side opposite the cavity exit were much lower with 3.3.2.2 Cavity Pressure IIistories h eaks in the range from 300 to 700 K.
The temperature maximums on the cavity exit side are Figure 3.6 through 3.13 plot the cavity and atttined on the sarne time scale as the containment containment pressure histories obtained in all of the pressure peaks. These measurements are consistent integral tests. The peak cavity pressure measured in with the observed behavior of hot blowdown gasses the tests is summarized in Table 3.3.
Yan and exiting the cavity during the sweepout phase.
Theofanous (1993) have postulated that the time interval over which a pressure difference exists 3.3.3.3 Containment Gas Temperatures between the cavity and the containment is proportional to a sweepout time interval, tu, of the The temperatures measured at various debris from the cavity. The ratio of the sweepout elevations in the upper dome are plotted in Figures interval to the blowdown time defines a coherence 3.27 through 3.34. The temperatures measured in the factor of the blowdown gas and debris.
This upper dome were lower than the subcompartment coherence factor plays an important role in temperatures. In contrast with the subcompartment calculating the pressure load with the model of Yan temperature responses, the peaks in the upper dome and Theofanous (1993). This issue is discussed temperatures lag the pressure response. The peak further in Section 4.
pressure is generally obtained at approximately 0.5 seconds and the peak upper dome temperatures are 3.3.3 Temperature Measurements indicated in the range of 1.0 to 2.0 seconds. One explanation for this measurement can be attributed to l
the slow response time of the thermocouples.
3.3.3.1 Cavity Gas Temperatures However, the 30 gauge wire bare junction Gas temperatures were measured in the thennocouples that were used in the subcompartment cavity in the IET-3, 6, 7 and UI A and UlB tests.
were also used in the upper dome. A more likely exP anation comes from the fact that the l
The gas temperatures were measured with the aspirated thermocouple assembly that is desenbed in thermocouples in the upper dome were not directly in Section 2. The cavity gas temperature and pressure the path of the hotjet of gasses that exited the cavity measurements are plotted in Figure 3.14 through and subcompartment. The thermocouples only began to respond after some mixing occurred.
39 NUREGCR-6168
m a'
m B
B 5'
m 5
800 4
s o
u 700 1
o 600 ll S
. Cavity 6
b 500 y
,o (D
I, CA l
b
!i (g o_
400 r
0'fhkhA$ESI@r'+'c=
O
~
300 l-/
Containment 200 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 o.8 0.9 1.o Time, sec s 1
Figure 3.6 Cavity Pressure IIIstory Olstained in IET-IRR l
L..
800 q
i i
700 o
600 a_
x d
b 500
<n (n
Q) 1 400 4
Cavity 4,_.. a.. _.,,, a......
v..,i 1
gp,,,,, j i - v v '
300
/
Containment w
2 0 0 I
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 m
Time, sec s k
a Q
R O"
Figure 3.7 Cavity Pressere History Obtained in IET-3 Q
i.,
n B
- c p,
I 800 4
s 700 o
600 4
O Cavity S
i t',
g b
500
[
a 8
lllg%dd% % h ww m e
O-400 300 I
Containment 200 O.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Time, sec s Figure 3.8 Cavity Pressure History Obtained in IET-6 l
i- -
i
____o
l 700 600 CAVITY o
500 Q_
M d
b 400 m
V) 1 l
l 1
300 W
,'J,1 ppm _ _
200 EV 100 O.0 0.1 0.2 0.3
- 0. 4-0.5 0.6 0.7 0.8 0.9 1.0 l
T.ime, sec 4
s g
Figure 3.9 Cavity Pressure History Obtained in IET-7 y
l l
O aw&
m l
5 800 4
$g u
700 o
600 o_
x i
s 500 (J l 1
~
w 0
1i
.Covity l
Q-400
~
U pyp y:;e:
nu,.,,w----~+
300 Contoinmant 200' 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1
Time, sec Figure 3.18 Cavity Pressure History Olitained in IET-8
..~.-l
h i
800 700 l
a 600 o_
x c;
a b
500 m
V)
Q) t Q-400 300 Cavity w w,,,m,w,,,,,,,,,,
ku_.-a m 0.0 0. k
((. 2 03 04 0.5 0.6 0.7 08 09 1.0 g
g 8
Time, sec g
W&
S y
Figure 3.11 Cavity Pressure History Obtained in UIA Q
t
...-..*+.,--,,#....
.y.
.--y%
r.r
.,,,,v.%,.3
.,e
-,-e--m..,
,-m-,,.,.,-v.,-r,-,,,%.w w
e-%.-
.e-
...,e, m-%.
rm.
..m.
w... ~.
w C)
Pi
- n 5
5 800 i
i i
i y
4 15 700 U
o 600 O
.x k
0 b
500 Cav.ty a
<n i
(A L
o-400 4
M ;"'.l:7.2': WL%[
Containment 200 O.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Time, sec Figure 3.12 Cavity Pressure History Obtained in UlB 1L.
- q i
800 700 o
600 o_
3 i
b 500 m
(a 8
1 400 Cav.ty i
300 l
Containment k
I 200 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Time, sec a
a t
s Figure 3.13 Cavity Pressure History obtained in U2 y
- = _ - -
_ = -
l l
(
l a
B m
D m
b 2500 4
i i
i 800
~
??
- 2100 700 -
- 1700 600 -
o a
O_
.x E
d
- 1300 s
500 p
m D
(n o
Cavity Pressure Q-400
.,,,t.,,m a,........
e y.
g, - 900 g
j m
...,v----
g Cavity Gas Temperature-500 300 J
Containment Pressure 100 2000.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Time, sec s Figure 3.14 Cavity Ces Temperature Measured in IET-3 a
800 2500 700
- 2100
\\ Cavity Pressure y
o 600
- 1700 p
0-i.
3 x
i o
E L.
500 i
8p%
1300 l
=
~;au w E
a>
t 9
s 400
[
- 900 g
~
1 0
Cavity Gas Temperature 300 f
Containment Pressure 500 200 100 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Time, sec s l
a e
S s
Figure 3.15 Cavity Ces Temperature Measured in IET-6 Q
l lI
O Q
B m
5 5
700 2500 4
i i
i i
s U
- 2100 600 M
Cavity Pressure
- 1700 p
o 500 a
o-
- + >
1 O
O
- 1300 8.
400 Cavity Gas Temperature y
~
l
~
E 8
m i
o i
- 900 g
$$nym,Algstco E
300 tu mu a....,, u mum,, ya;n..
o I
,, n
- 500 200 f
Containment Pressure 100 1000.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Time, sec Figure 3.16 Cavity Gas Tessperature Measured in IET-7 J
800 2500 700 -
- 2100 o
600 1700 6
5 Q-
~
x d
s 500
- 1300 3
8 E
o e
I-L 1
400 Cavity Gas Temperature
- 900 moo 300 Cavity Pressure
- 500 l
w w > m s::&::::::,::::.
100 Q
200 "^4'*'2'"
0.0 0.1
-0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 g
Time, sec s D
a 4
a 5
b l
5 G
Figure 3.17 Cavity Gas Temiperature Measured in UIA y
1 5
8 e
e 2500 l
5 800 s
- 2100 a
700 -
Cavity Gas Temperature x
- 1700 p
600 -
o a
a-
~
x E
g
-- 1300 b
500 1
E I
m 8
j e
e 400
, Cavity Pressure ~
- 900 m
i o
O wha
-wct.ead,y 500 a00 Cantainment Pressure 100 200 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Time, sec Figure 318 Cavity Gas Temperature Measured in UIB l
1600
~C8-7
,N
~
1400 M
1200 4
Amplifier Saturated 8
a p
1000 e
o i
TC8-18 800 A
I
[
f TC Failed S
600 l
TC8-8 400
~
r 200 l
0 1
2 3
g M
o T.ime, secs g
g i
!E U
S Figure 3.19 Subcompartment Gas Temperatures Obtained in IET-1RR
m l
6m B
w g
1600 e
w 1400 M
1200 v
M y,
1000 b
TC8 o_
~
E 800 TCB-7 o
l-m i
g 600
/
TCB-8
~
t
/
400 TC8-9 Foiled TCB-9 t
200 0
1 2
3 Time, sec s Figure 3.20 SubcomPSFI"'", c., Temperatures Obtained in IET-3
.m.--
.m.
i TC8-7 Failed c
1400 M
1200 TC8-7 8
a o
1000 L
a>
~
~
TC8-18 E
800 Amplifier Saturated m
S 600 400 TC8-8 200 O
1 2
3 2
1 8
Time, sec s i
5 6
s E
Figure 3.21 Subcompartment Gas Temperatures Obtained in IET-6 y
l
i J
~
l 8
5 l
1600 Amplif;er Saturated ja i
n 1400 M
1200 TC8-18
?
3 0
1000 L
h
[
800 H
(o S
600 TC8-8 400 200 0
1 2
3 Time, sec s Figure 3.22 Subcompartment Gas Temperatures Obtained in IET-7
=i
l 500 x
p 400 TC8-18 a
~o s
e o
,./__.,_..._._._._.__.__.._._._._..___._
[
TC8-8 g
l--
m 300 Oo m
m9 l
200 2
0 1
2 3
n la 4
g Time, sec s g
- c O
5 Figure 3.23 Subcompartasent Gas Temiperatures Obtained in IET.8 M
= -
h 8a
- o I
k 1600 g
i i
!3 u
1400 M
1200 TC8-7 8a 13 1000
~
u
~
[
800 TC8-9
~
H o
600
~
TC8-8 TC8-10 400
[
TC8-18 200 O
1 2
3 4
Time, sec Figure 3.24 Subcompartment Gas Temperatures Obtained in UIA
1600 eAmplif.ier Saturated i
1400 TC8-7 i
^
y 1200 8
a 5
TC8-18 1000 l
e e
a E
800 ff TC8-10 m
9O 600 t
/
TC8-8 I
400 t
v 0
1 2
3 Time, sec 4
o D
1 e
Figure 3.25 Subeempartenent Gee Tesaperatures Obtained in UlB Q
1 i
i t
.~y---wer-.
,..--,e:+e..
y
,-+
m..-.m
+
.-~ -.--..
--.s v....o~-
e
..--r-
- - - - - ~. - -, -, - - -
~
I Oax dh g
a 1600 g
i 3
4 1400 TC8-7 s
x 1200
's '
~.
.v s
t 3
NTC8-1 y
1000 rdr..
s
~~.'.
e l
H 8
a.
..TC 8 - 9 5
800 l,l':.
.._..~~..'m"===
s m
- - ~ - ~
.<TC 8 - 1 b~~ ~'" *'..-...
-~...~.,.
O
......~
o 600
. ~.
i 400 f
~/
- 't
/
.e.f.
- 200 i
0 1
2 3
4 Time, sec Figure 3.26 Subcompartment Ces Temperatures Obtained in U2 f
1 I
.A
800 i
i i
i H = Height Above Operating Deck 700 p
600 E
E e
500 E
g 400 H = 0.75 m
~
O 300 H = 2.25 m t
I E
f I
l 0
1 2
3 4
5 8
Time, sec s a
5 5
h-Figure 3.27 Upper Dome Gas Temperatures Obtained in IET-IRR M
e 2
9 i
800 E
H = Height Above Operating Dec k u
700 p
600 B
E e
500 E,
H = 2.25 m q
H 400 o
H = 0.75 m O
H = 1.50 m 300 200 O
1 2
3 4
5 Time, sec s Figure 3.28 Upper Denne Gas Tennperatures Obtained in IET-3 i
N..
800 H = Height Above Operating Deck 700 H = 0.75 m x
~
~
u l.
6 600 a
"o
(
L S
500 t
E H = 1.50 m o
i f-m 400 O
O J
300 1
l f
200 l
0 1
2 3
4 5
Oa Time, sec M
l b
Figure 3.29 Upper Denne Gas Teseperatures Obtained in IET-6 Q.
m 1
e 9
D l
k s
800
. H' = bleight Above Operating dec k s
u H = 0.75 m 700
.3 600 E
g g
H = 1.50 m Ey 500 o
H = 2.25 m m
o
~
400 H = 0.0 m k
300 O
1 2
3 4
5 6
7 8
9 10 Time, sec s Figure 3.30 Upper Denne Gas Temperatures Obtained in IET-7 l
l l
I 800 H = Height Above Operating Deck 700 o
600 L
.-...._...........-.--------::------~~~--
.a o
_. _. ~.. ~..
u 4..
~_.. _.. -=~~
_r.;*..-.. --__,,.= n
-~=.~
~~~.r.-~.~.=;
e a
500
==.
o_
. ~. - - _-n
.u -
E
~
~
H = 0.79 m w
400 H = 1.22 m Oo H = 1. 6 3 m H = 1.83 m 300 H = 2.13 m H = 2.59 m m
200
]
O 1
2 3
4 5
fis O
Time, sec s a
aW q
C:
h Figure 3.31 Upper Dome Gas Temperatures Obtained in IET-8 U
h n
oan
~
t D
8 800 g
H = Height Above Operating Deck l
700 H = 0.79 m x
H = 1.22 m
~
d 600 H = 1.63 m b
H = 2.13 m y
H = 2.59 m 500 E
I-m 400 0
0
.::_.---~-r===u===----~~-------------------~~-----~_.
200 O
1 2
3 4
5 Time, sec s Figure 3.32 Upper Dome Gas Temperatures Obtained in UIA
. N 800 H = Height Above Operating Deck 700 H = 0.79 m y
~
H = 1.22 m 6
600 H = 1.63 m l
H = 2.13 m W
O L
e 500 l
1 Eo g
m 400 O
O
.......=-,--:...--....-------------------_-....-.-.-..-..-.
300
=
he i
200 l
0 1
2 3
4 5
m g
Oa Time, sec s a
- o td b
S E
Figure 3.33 Upper Dome Gas Temperatures Obtained in UlB U
r O
D
@m b
4
=
g 800 s
H = Height Above Operating Deck-a 700 4
~
M H = 1.22 m e
600 H = 1.83 m 3
H = 0.79 m -
E 500 E
H = 1.63 m -
o 400 y H = 2.59 m _
o 0
H = 2.13 m -
300 3
200
'O 1
2 3
4 5
Time, sec s Figure 3.34 Upper Denne Gas Temperatures Obtained in U2
.1 EXPERIMENT RESULTS The thermocouples were placed along the centerline observations are consistent with large debris oxidation of the expansion vessel.
The temperature rates occurring during the sweepout process.
measurements can be considered accurate in these regions after some mixing of the heated blowdown The gas samples taken in the upper dome gasses and the colder expansion vessel upper dome give a measure of the total amount of hydrogen gasses.
produced and bumed by considering the change in hydrogen and oxygen concentrations from the initial In general, higher temperatures rises were condition. These results are given in Section 4.
measured in tests with hydrogen combustion. Peak increases were measured in the range of 400 to 450 3.3.5 Debris Disposition Measurements K in the hydrogen combustion tests. Conversely, in the inerted tests peak increases were measured in the The post-test disposition of the debris is range of 100 to 150 K.
The magnitude of the summarized in Table 3.5. The sweepout fraction for temperature rises decreased with increasing elevation tests with a nominal driving pressure of 6.2 MPa above the operating deck. This indicates that hot were in the range of 0.70 to 0.80. The exceptions to gasses exiting the cavity mixed and cooled with this were the lower pressure tests, UI A and U2. In upper dome gasses.
these tests the sweepout was much lower. The data indicates the trapping ability of the subcompartment 3.3.4 Gas Composition Measurements structures. In these tests 90 to 95 percent of the i
debris was trapped and prevented from entering the The gas composition was measured at upper dome. This had a significant mitigating effect various locations and times in the tests by the use of on the DCH load.
gas sample bottles. The hydrogen and oxygen concentrations are given in Table 3.4 in mole percent.
3.3.6 Particle Size Measurements The complete analyses for all the bottles is given in Appendix A. Note that the concentrations reported A partic1c size distribution measurement was i
are the raw measurements of the non-condensables made for debris dispersed to the upper dome in IET-obtained from mass spectrometer analysis. Only the IRR,3,6 and 7. The particle sizes were measured l
predominant species are reported. Because of this the by a sonic sifter. Debris from other regions was not columns do not add to 100%. There was the presence analyzed because this debris typically consisted of of trace amounts of gasses which were not analyzed.
agglomerated particles. However, debris dispersed to The IET-8 test, which had a high steam the upper dome had the most likely probability of l
concentration, had much higher hydrogen and oxygen retaining the size produced by the HPME. The concentrations in the gas samples compared to the distributions are plotted on a log-normal plot in other tests.
This is because only the non-Figures 3.35 through 3.38. These plots indicate that condensables are analyzed.
the distribution could be considered roughly log-normal. However, an upper limit is not indicated.
The gas sample data in Appendix A show The mass median diameters are summarized in Table measurable amounts of CO and combustible CO.
3.6 2
These species most likely result from the decomposition of concrete in the cavity and subcompartment models. The CO was not considered in the gas combustion analysis presented in Section 4 because the amounts were an order of magnitude less than the hydrogen.
The cavity sample bottles gave consistently high hydrogen concentrations. This is consistent with previous measurements by Allen et al(1991). These 1
i I
3 Ek7'ERI. VENT RESULTS Table 3.4a Gas Compoillion Measurements-Hydrogen Concentrations in mole percent Location Timing, secs IET-lRR IET-3 IET-6 IET-7 IET-8 UIA UlB U2 Cavity 0.0-0.5 73.4 28.6 33.0
'i4.8 -
58.2 Cavity 0.1-0.6 49.8 60.7 51.3 32.1 Cavity 0.0-1.0 5.4 Cavity 15.0-16.0 11.2 18.2 Cavity 60.0-61.0 Seal Table 1.25-1.75 33.1 62.3 55.7 4.7 Upper Dome
Background
0 0
2.0 0
7.3 0
0 2.6 3.1 4.4 3.1 Upper Dome 5.0 -5.0 3.2 4.5 3.0 Upper Dome 15.0-16.0 2.2 2.0 3.3 4.1 2.6 Upper Dome 30.0-31.0 Upper Dome 60.0-61.0 3.4 0.95 2.6 2.6 18.3 3.5 4.2 2.6 Upper Dome 450.0-451.0 3.3 0.98 2.7 2.8 17.9 3.9 4.7 2.6 l
l l
l l
l l
l NUREG/CR4168 70
1 3 EXPERLUEb7 RESULTS Table 3.4b Cas Composition Measurements-Oxygen Concentrations in mole percent l
Location Timing IET-lRR IET-3 IET4 IET-7 IET-8 U1A U1B U2 Cavity 0.0-0.5 0.0026 8.6 5.6 5.7 4.1 Cavity 0.1-0.6 0.0005 1.5 0
1.9 Cavity 0.0-1.0 l
Cavity 15.0-16.0 4.0 Cavity 60.0-61.0 14.3 3.7 Seal Table 1.25-1.75
<0.0005 0.9 1.3 8.3 Upper Dome
Background
0.12 10.8 9.9 10.1 15.6 0.57 0.47 11.6 Upper Dome 5.0-6.0 0.41 0.18 8.0 Upper Dome 15.0-16.0 0.40 0.23 7.9 Upper Dome 30.0-31.0 8.3 7.9 0.64 0.39 9.9 Upper Dome 60.0-61.0 0.071 9.3 8.1 6.7 12.2 0.63 0.32 8.8 Upper Dome 450.0-451.0 0.22 9.2 8.2 6.9 11.7 0.53 0.28 9.3 l
1 l
1 71 NUREG/CR-6168 i
m_..
3 EXPERIMENT RESULTS Table 3.5 Debris Disposition Measurements
- .A;
-. Jg :;Ap ET-lRR ET-3 IET-6 IET-7 ET-8 UlA UlB U2 A. Initial Melt Mass, grams 820.0 820.0 713.0 713.0 713.0 1130.0 1130.0 1130.0 B. MGl 43.3 67.3 30.3 4.0 11.8 53.2 50.0 23.3 C. Cavity and Chute 260.8 232.2 262.7 153.7 179.3 898.3 169.5 820.4 D. Seal Table Room 148.9 163.1 167.9 113.6 158.7 80.4 167.9 0.0 E. Remaining Subcompartment 358.2 428.2 339.6 448.9 405.3 60.0 636.2 343.8 F. Total Sube,mpart. = D + E 507.1 591.3 507.5 562.5 564.0 140.4 804.1 343.8 O. Upper Dome 114.6 37.8 81.3 26.2 22.6 7.37 48.5 0.0 H. Total Collected 925.8 928.6 881.8 746.5 804.5 1165.6 1072.0 1187.5
' I. WS N' '-
U Transport Fractions t
f, = 1 - B/A 0.947 0.918 0.966 0.994 0.984 0.953 0.956 0.979 f% = (F+G)/(C+F+G) 0.705 0.734 0.6'91 0.793 0.766 0.190 0.795 0.295 fun = G/(C+F+G) 0.13 0.044 0.096 0.035 0.030 0.0071 0.048 0.0 Table 3.6 Particle Size Measurements ETlRR IET-3 IET-6 IET-7 Mass Median Diameter, microns 450 990 1000 300 I
t NUREG/CR-6168 72
il I!l lI!\\1 1,
ll
" Bgm4 Bsg 9
9 R
9 R
7 ::.
=
1 9
T 9
E I
41}
9 n
Iit{.
9 i
e mo D
9 r
3rr 9
e i-Iiijr p
p U
e 5
h 9
e t
o g
0 g
t x
d 9
a e
Y s
t r
n e
0 p
~
8 e
s i
c D
~
0 r
s 7
ir h
e b
P eD 0
f 5
o e
n v
o
'R _.
0 i
i t
t u
3 a
b k
ir 0
l t
2 u
s iD m
e 0
z u
i 1
S K_
C e
l 5
c g
i tra P
5 1
3 3
erug iF 1
1
=.
- =...
= :; = =.
0 4
0 0
0 0
0 0
1 1
0 1
1 ue bE E.a $ e.v>
e z5g" @
1l lliljll lI I1 ll
4 3
10 w
4 s
g i
g i
k y
' g is j
p E
U 1000 = c w
,t
_.:_:T
~
c
'u a)
~
Q) w E
=
.m V
Q
=
r o>
m 100 s
U)
K r
g 10
.01
.1 1
5 10 2030 50 7080 90 95 99 99.9 99.99 Cumulative Percentage Figure 3.36 Particle Size Distribution of Debris Dispersed to the Upper Dome in IET-3
l 4
I 1
10 zz.
=
.....g
- ...~--g es
.i E
1000 4
g=
g
_g-e k
e
~
E
=
=
3,
.9a m
o 100
~
is
- r+
(
)
_g.
=
3 m
10
.01
.1 1
5 10 2030 50 7080 90 95 99 99.9 99.99 s
a Q
Cumulative Percentage i
l3 Figure 3.37 Particle Size Distribution of Debris Dispersed to the Upper Dome in IET-6 Q
m g,$ 6 g 99
1,.
9
_j
=
=
~
9 9
9 7-9 T
E I
n i
9 e
9 moD re 5
p 1
I p
9 U
1 e
0 g
h e
I
_ D 9
a t
o s
t t
g-0 n
de 8
e h
sr 0
c e
7 r
p f
e is
\\
P D
s 0
ir w~
5 e
be b%
v D
i h
0 t
fo 3
a n
\\
l o
0 u
i t
2 u
g m
b g
0 u
ir ts C
1 i
D N
5 ez iS e
lc i
tr 1
a P
8 3
3 e
1 t
rug iF 1
_. =
~
=
0
- =
- a -
- =
=
0 0
0 0
1 Q
0 1
j 0
1 E(ygbEm e $.- @
gngg" a
l1 l'
l
4 ANALYSIS AND DISCUSSION 4 ANALYSIS AND DISCUSSION 4.1 Sweepout Phenomena made if the difference in the cavity and containment pressure normalized by the containment pressure is P otted versus dimensionless time. Where time is l
An important part of the DCH phenomena is made dimensionless with the blowdown time the sweepout of debris from the cavity and the accompanying metal oxidation and blowdown gas e nstant, t,.
This is done in Figure 4.2. Three heat up. Understanding this phenomena is required differences can be noted when comparing the two in order to have predictive capability of DCH loads.
curves in Figure 4.2: 1) The magnitude of the The experimental data presented in Section 3 show pressure difference is greater in the higher driving that the sweepout process results in high heat transfer pressure test; 2) the pressure difference is shifted rates and extensive metal oxidation by the blowdown later in time for the low driving pressure test; and 3) steam. This is indicated by the high measured gas the duration of the pressure difference is shorter for temperatures and the high concentrations of hydrogen, the low pressure test. If this data is to be used for estimating the coherence factor then a threshold or compared to other regions of the containment,in the cavity. The vigorous two-phase mixing process that cutoff cavity pressurization must be defined. Figure occurs in the cavity during sweepout has been 4.3 plots the estimated coherence factor from the documented extensively (Spencer et al,1982; Tutu, cavity pressurization data as a function of the cutoff N. K. et al,1988). In the limit of one hundred Pressure. The duration of the cavity pressurization and/or the coherence factor magnitude is clearly percent trapping of debris by the subcompartment structure the DCH load will result from the heat up of dependent upon the threshold pressure level at which the blowdown gas during the cavity sweepout. The the cavity is defined to be pressurized. However, Convection Limited Containment Heating (CLCH) regardless of the definition of the pressure threshold, the duration of the elevated pressure period is clearly model developed by Yan and Theofanous (1993)
I nger in the higher pressure IET-6 test in comparison incorporated this idea and yielded good predictions of to the lower pressure UI A test.
l the Zion NPP experiments presented here.
Figure 4.3 shows that the sweepout interval The important modeling parameter required increases with increasing driving pressure for the range of pressures considered here (3.0 MPa < Paes, for the CLCH and TCE models concerns the
< 6.6 MPa). However, it should be noted that for coherence of the melt sweepout and blowdown of the primary system. A coherence factor, tu/t,, can be higher driving pressures a limiting pressure is defined where tu is the time duration over which expected to be reached where nearly complete sweepout of the melt will occur. For pressures in this melt is swept from the cavity and t, is the primary system blowdown constant defined earlier in Section range the coherence factor would decrease with
- 3. This coherence factor is a measure of the extent of mereasmg pressure.
interaction between the fragmented melt and the blowdown gasses. The cavity pressure history data 4.2 Hydrogen Production and presented in Section 3 can be used to estimate the Combustion coherence factor. Following Yan and Theofanous this is done by postulating that the time interval over The tests conducted in this program yielded which a pressure difference exists between the cavity a considerable amount of data on the production and and the containment is equivalent to the melt combustion of hydrogen during the HPME sequence.
sweepout time, tu. For example a comparison of the Estimations of the hydrogen production and cavity sweepout in IET-6 and Ul A is made in Figure combustion for all of the tests are shown in Table i
4.1.
These two tests were chosen because of the 4.1.
These results where obtained from the data greater than factor of two difference in initial driving given in Table 3.4 and through use of the ideal gas pressure. It is assumed that the affect of the property law. The data on the hydrogen in tests where i
differences are second order compared to the driving l
pressure. A more meaningful comparison can be 77 NUREG/CR-6168
e 6
0 5
b 700 e
i b
R e!3 600 IET-6 R
\\
i l'
o D-x 500 i
,!( hfikMhNhWWW
~
?
l t
m m
in e
400 O_
300 j
U1 A
%6AA AAApA^ANA%A^^^-
M * ^ * * "'
200 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Time, sec s Figure 4.1 Comparison of the Cavity Sweepout for IET-6 and UI A I
I 1.5 i
~
\\ IET-6 W
1.2
\\
mx b
g g 0.9 1
y 1
d I
o h'
U h %
0.6 I
l fl U
0 1
U1 A j
s 0.3 -l 1
.a
(/
??sFi( -
[
l.
p
(
- *+;
E
+ *' ' #24 ' * *U b%f%*Hww
~
0.0 5
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 l
b t/T R
S W
b N
i E
Figure 4.2 Cesaparlsen of the Cavity Sweepout for IET-6 and U1A in Dimensionless Form g
=
^
~
n N<"
n n
g 0.8 i
i i
a s
e b
e 0'7 o
U1A
~
R IET-6 E
~
0.6 o
g 0.5 o
e"
~
~
o 0.4
~
5 e
o 0.3 o
o e
0.2 oo 0.1 e
9 0.0 O.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 CAVITY CONTAINMENT g
CONTAINMENT Figure 4.3 Estimated Coherence Factors as a Function of the Cutoff Casily Pressurhation 1
'T
l 4 ANALYSIS AND DISCUSSION Table 4.1 Hydrogen Production and Combustion l
ET-lRR ET-3 ET-6 ET-7 ET-8 UIA UlB U2 H Pre-existing, g-moles 0
0 2.3 0
3.0 0
0 3.1 0 Depleted, g-moles 0
1.8 2.1 1.8 0.4 0
0 3.0 2
H, Produced', g-rnoles 4.0 4.7 4.9 5.2 5.2 5.0 6.0 6.0 H Burned', g. moles 0
3.5 4.2 3.6 0.8 0
0 6.0 2
Fraction of H Burned' O.0 0.75 0.58 0.69 0.10 0.0 0.0 0.66 2
' This data is calculated assuming all of the oxygen depletion occurs by recombination with hydrogen hydrogen could burn were calculated assuming all of approximately 2.0 seconds. This is associated with the oxygen depletion occurs from hydrogen an increase in temperature at some of the upper dome recombination.
thermocouple locations. These data support the idea that a localized hydrogen burn occurred well after the The hydrogen production data in the inert blowdown completed. A second explanation for the tests are consistent with complete oxidation for the hydrogen burn measurements shown in Table 4.1 is exothermic metals (zirconium and chromium) in the the possibility that not all of the oxygen depletion snelt and only a small fraction of the iron. These arose from hydrogen recombination. The validity of results are not unexpected and are consistent with this assumption can be addressed by plotting the earlier measurements made by Allen et al. (1991).
hydrogen and oxygen measurements as a function of The metal oxidation occurs rapidly during the cavity time after the start of the HPhE. This has been done sweepout. This results in a hot jet of hydrogen and in Figure 4.2.
This plot shows the number of steam exiting the cavity.
hydrogen moles staying constant over a long time scale after the HPhE. However, the number of The hydrogen in the jet that exits the cavity oxygen moles continue to decrease well after the will partially burn ifit accesses an oxygen containing HPhE. This may be occurring due to slow oxidation atmosphere in the containment. A flaming jet exiting of hot metal in the debris. A third possibility is that the cavity and subcompartment was clearly evident in steam continues slowly oxidizing hot metal followed the video and high speed film recorded in ET-3,6, by immediate recombination of hydrogen. This 7 and U2. Flames were not evident in the nitrogen scenario could also result in the slow decrease of the inerted tests ET-lRR, UIA, and UlB and in the oxygen inventory and the steady hydrogen inventory steam atmosphere test ET-8.
since the hydrogen would be continually burned and replenished. The conchision is that there is an The data in Table 4.1 show extensive inherent uncertainty in these measurements and the hydrogen combustion in tests where oxygen was data given in Table 4.1 is only an upper bound. The present, with one exception, ET-8. However, the important conclusion is that combustion of hydrogen amount of hydrogen consumed is not consistent with and subsequent energy release did not occur on a the relatively low actual measured DCH loads. There time scale coherent with the blowdown of the system.
are three possible explanations for this occurrence.
Therefore, the actual DCH loads were smaller than The first is that the hydrogen combustion occurred would be expected from the hydrogen combustion over a long time scale and was not completely shown in Table 4.1.
coherent with the HPhE. There is substantial A second qualified conclusion can be drawn evidence of this occurring in U2. In the U2 test a from the ET-8 test with a prototypic steam second plateau in the pressure occurred at atmosphere. In this test the combustion of hydrogen 81 NUREG/CR-6168 i
5 m
h e
N E
6 x
G 16 i
i i
i b
e U2 H2 R
0 U2 02 e
14
=
IET-6 H2
~
O lET-6 02 12 0
10 o
E O
~
O E
8 i
oi 6
4
~
e 2
0 O
100 200 300
'00 500 Time, see Figure 4.4 Plot of the Oxygen and Ilydrogen Moles in IET-6 and U2
4 ANALYSIS AND DISCUSSION was almost completely suppressed. However, it is noted that the suppression of hydrogen combustion in HPME sequences may be scale dependent as evidenced by the occurrence of significant hydrogen combustion in larger scale tests at SNL with prototypic atmospheres.
4.3 Comparison of Corium and Iron Alumina Thermite Melt Simulants A main objective of these tests was to assess possible distortions introduced by the use of non-prototypic iron-alumma thermite as a core melt simulant. Several differences in the composition, chemical and thermal energy content, and physical properties were pointed out in Section 2.
These differences partially manifested themselves in the integral experiments. However,in terms of the actual measured DCH load, the differences were small.
l l
83 NUREG/CR-6168 4
.1
SUMMARY
AND CONCLUSIONS 5
SUMMARY
AND CONCLUSIONS The results of Direct Containment Heating (DCH) integral experiments are presented. The experiments simulated a high pressure melt ejection in the Zion Nuclear Power Plant. Experiments were conducted in a 1/40 scale model of the Zion containment. The model included the vessel lower head, cavity and instrument tunnel, and the lower containment simctures. The experiments were driven with steam.
There were two main objectives of these experiments. The first was to investigate the effect of scale on DCH phenomena. The IET test series addressed this by conducting counterpart integral tests in a 1/40 scale facility at Argonne National Laboratory and in a 1/10 scale facility at Sandia National Laboratories. Iron-alumma thermite with chromium was used as a core melt simulant in the IET test series. The second objective was to address potential experiment distortions introduced by the use of non-prototypic iron / alumina thermite. The second objective was met in the U series of tests which l
utilized a prototypic core melt. Corium experiments, UlB and U2, were conducted that were counterpan i
to the IET-IRR and IET-6 iron /alununa tests, respectively. In addition to meeting these two important objectives, two specific findings were i
obtained. These are listed below.
1.
The subcompartment structures efficiently trapped 90 percent of the debris leaving the
- cavity, This causes the extent of debris / atmosphere interactions to be significantly reduced.
In the limit of complete trapping the DCH load is confined to the heat up of the blowdown gasses during the melt sweepout process.
2.
Comparison of counterpart iron / alumina and corium tests indicated a very small effect of non-prototypic melt simulant on the measured DCH load.
)
l 85 NUREG/CR-6168
1 I
l l
\\
6 REFERENCES 6 REFERENCES 1
Allen, M. D., M. Pilch, R. T. Nichols and R.
Heating with Application to the Design and j
O.
- Griffith, 1991,
- Experiments to Specification of an Experiment program for Investigate the Effect of Flight Path on Resolving DCH Issues,' SAND 91-2784, Direct Containment Heating (DCH) in the Sandia National Laboratories, Albuquerque, Surtsey Test Facility," NUREG/CR-5728, N. M.
S AND91 1105, Sandia National Laboratories, Albuquerque, NM.
Pilch, M. M.,1992, " Development of the Single-Cell Adiabatic Equilibrium Model for Allen, M. D, M. Pilch, R. T. Nichols.R. O.
Direct Containment Heating," SAND 92-Griffith and T.
K.
Blanchat, 1992a, 0085, Sandia National Laboratories,
' Experiments to Investigate the Effects of Albuquerque, NM.
1:10 Scale Zion Structures on Direct Containment Heating (DCH) in the Surtsey Spencer, B. W., D. Kilsdonk, J. J. Sienicki Test Facility: The IET-l and IET-lR Tests,"
and G.
R.
Thomas. "Phenomenlogical S AND 92-02 5 5, Sandia National Investigations of Cavity Interactions Laboratories, Albuquerque, NM.
Following Postulated Vessel Meltthrough,"
Proceedines of the International Meetine on Allen, M. D., M. Pilch, R. T. Nichols.R. O.
Thermal Nuclear Reactor Safety. Chicago, Griffith and D. C. Williams,1992b, "The IL August 29-September 2,
- 1982, Third Integral Effects Test (IET-3) in the NUREG/CR-0027, USNRCS,1983, Vol. 2.
Surtsey Test Facility," SAND 92-0166, pp 923-973 Sandia National Laboratories, Albuquerque, NM.
Spencer, B. W., J. J. Sienicki end L. M.
McUmber,1987, " Hydrodynamics and Heat Allen, M. D., T. K. Blanchat, M. Pilch and Transfer Aspects of Corium-Water R. T. Nichols,1992c, "An Integral Effects Interactions, EPRI Report NP-5127, Argonne test in a Zion-like Geometry to Investigate National Laboratory, Argonne, II.
I the Effects of Preexisting Hydrogen on Direct Containment Heating in the Surtsey Tutu, N. K. et al.,1988, " Debris Dispersal Test Facility: The IET-6 Test," SAND 92-from Reactor Cavities During High-Pressure 1802, Sandia National Laboratories, Melt Ejection Accident Scenarios,"
Albuquerque, NM.
NUREG/CR-5146, Brookhaven National Laboratory, Upton, NY.
- Levy, S.,
1991, Appendix G in "An Integrated Structure and Scaling White, F.,1974, Fluid Mechanies. McGraw-Methodology for Severe Accident Technical Hill, New York, N. Y.
Issue Resolution,' NUREG/CR-5809, EGO-2659.
Yan, H. and T. O. Theofanous,1993, "The l
Prediction of Direct Containment Heating,"
Moffat, R.
J.,
1962, " Gas Temperature ANS Proceedings of the 1993 National Heat Measurements,'
in Temrierature-Its Transfer Conference, August 8-11, 1993 Measurement and Control in Science and Atlanta, Ga., p 294-309.
Industry. Vol. 3, Part 2, Rheinhold, New York, N. Y., pg. 553-571.
Pilch, M. and M. D. Allen,1991, *A Scaling Methodology for Direct Containment 87 NUREG/CR-6168 l
i
APPENDIXA i
l Appendix A RESULTS OF GAS BOTTLE ANALYSIS FOR THE INDIVIDUAL TESTS I
The results of the gas bottle analysis for the individual tests is given in this appendix. The results are presented in mole percent of the non-condensable species ofinterest. Because of this a sum of the result will not add to 100 percent. This arises from errors in the measurements and the presence of trace amounts of other gas species. The results are presented as obtained from the mass spectrometer. No attempt was made to re-normalize the data.
)
i i
i I
i l
\\
A1 NUREG/CR-6168 I
h l
I
8 n
5 n
A a
ca Table A.1 Gas Bottle Analysis for IET-1RR Bottle / Location Timing, see II,, mole %
O,, mole %
N, mole %
CO, mole %
CO,, mole %
- l. Cavity 0.0 - 0.5 73.4
- 1.4 0.0026
- O/)004 10.2
- 0.46 14.5
- 1.5 1.47
- 0.07
- 2. Cavity 0.1-0.6 49.8 1.0 0.00050
- 0.0005 35.5
- l.1 8.9 i 0.9 4.6
- 0.2
- 3. Seal Table Room 1.25 - 1.75 33.1
- 1.0
<0.0005 44.5
- 1.7 12.1 i 1.2 3.310.2
- 4. Upper Dome
Background
<0.01 0.12
- 0.01 99.9
<0.005 0.001
- 0.003
- 5. Upper Dome 60.0 - 61.0 3.4
- 0.2 0.078
- 0.004 95.5 0.7
- 0.1 0.19 i 0.01
- 6. Upper Dome 60.0 - 61.0 3.4
- 0.2 0.080
- 0.004 95.4 0.7 i 0.1 0.19
- 0.01
- 7. Upper Dome 60.0 - 61.0 3.5 i 0.2 0.054
- 0.003 95.4 0.7 i 0.1 0.17 i 0.01
- 8. Upper Dome' 450.0 - 451.0 0.15
- 0.03 12.1
- 0.3 87.2 0.34 i 0.05 0.12
- 0.02
- 9. Upper Dome 450.0 - 451.0 3.3
- 0.2 0.22
- 0.01 95.5 0.7
- 0.1 0.17 i 0 02
- 10. Upper Dome 450.0 - 451.0 3.2
- 0.2 0.22
- 0.01 95.6 0.7
- 0.1 0.1810.00I
'This Bottle Leaked 7
Table A.2 Gas Bottle Analysis for IET-3 Bottle /1.ccation Timing, sec 11, mole %
O,, mole %
N,, mole %
CO, mole %
CO,, mole %
3
- 1. Cavity 0.0 - 0.5 28.6
- 1.2 8.6
- 0.3 49.5
- 2.0 10.6
- 1.1 2.1
- 0.1
- 2. Cavity 0.1-0.6 60.7
- 2.2 1.5
- 0.004 21.0
- 0.8 10.7
- 1.I 5.1
- 0.2
- 3. Seal Table Room 1.25 - 1.75 62.3
- 1.9 0.93
- 0.03 11.2
- 0.5 14.0
- I.4 5.6
- 0.3
- 4. Upper Dome
Background
<0.0 l 10.8
- 0.3 88.8
<0.02 0.01 I i 0.00I
- 5. Upper Dome 60.0 - 61.0 0.95
- 0.05 9.3
- 0.2 88.3 0.12
- 0.02 0.67
- 0.03
- 6. Upper Dome 60.0 - 61.0 0.93
- 0.05 9.2 i 0.2 88.4 0.17
- 0.03 0.69
- 0.04
- 7. Upper Dome 60.0 - 61.0 0.96
- 0.05 9.3
- 0.2 88.3 0.16
- 0.03 0.68
- 0.04
- 8. Upper Dome 450.0 - 451.0 1.0
- 0.05 9.2
- 0.2 88.4 0.17
- 0.03 0.68 i 0.03
- 9. Upper Dome 450.0 - 451.0 0.98
- 0.05 9.1
- 0.2 88.4 0.20
- 0.03 0.67
- 0.03
- 10. Upper Dome 450.0 - 451.0 0.97
- 0.05 9.3
- 0.2 88.2 0.02
- 0.03 0.67
- 0.03 i
Od
- o b
Nx
I N
't 8
Od;c N
b A
E Table A.3 Gas Bottle Analys!s for IET-6 11ottle/ Location Timing, sec II,, mole %
0, mole %
N, mole %
CO, mole %
CO,, mole %
3
- 1. Cavity 0.0 - 0.5 33.0 i 1.0 5.6
- 0.1 54.2
- 1.1 6.4
- 0.6 0.37
- 0.2
- 2. Cavity 0.1 - 0.6 51.3
- 1.3 0.0014
- 0.0006 36.6
- 0.8 9.1
- 0.9 2.15
- 0 06
- 3. Seal Table Room 1.25 - 1.75 55.7
- 1.4 1.26
- 0.03 21.0
- 1.1 11.0
- 1.1 4.8
- 0.2
- 4. Upper Dome Dackground 2.0
- 0.1 9.9 i 0.3 87.5
- 0.6
<0.01 0.013
- 0.003
- 5. Upper Dome 60.0 - 61.0 2.510.1 8.1
- 0.2 87.9
- 0.5 0.15
- 0.03 0.54
- 0.02
- 6. Upper Dome 60.0 - 61.0 2.7
- 0.1 8.2
- 0.2 88.1
- 0.5 0.17 i 0.03 0.54
- 0 02 I
- 7. Urper Dome 60.0 - 61.0 2.6
- 0. I 8.0
- 0.2 88.2
- 0.5 0.15
- 0.03 0.50
- 0.02
- 8. Upper Dome 450.0 - 451.0 2.7 i 0. I 8.1
- 0.2 87.9
- 0.5 0.19
- 0.05 0.52 i 0.02 l
l
- 9. Upper Dome 450.0 - 451.0
<0.0 l 19.7
- 0.3 79.2
- 0.4
<0.01 0.134
- 0.006 I0. Upper Dome 450.0 - 451.0 2.6
- 0.1 8.3
- 0.2 87.8
- 0.5 0.I7
- 0.03 0.53
- 0.02
- 11. Upper Dome 30.0 - 31.0 2.3
- 0.1 8.2
- 0.2 88.3
- 0.5 0.12
- 0.04 0.5010.02 l
- 12. Upper Dome 30.0 - 31.0 2.010.1 8.3
- 0.2 88.4
- 0.6 0.15 i 0.05 0.5210.03 i
- 13. Upper Dome 30.0 - 31.0 2.2
- 0.1 8.3
- 0.2 88.3
- 0.5 0.12 i 0.03 0.50
- 0.02
Table A.4 Gas Bottle Analysis for IET-7 Bottle / Location Timing. sec 11, mole %
O,, mole %
N,, mole %
CO, mole %
CO,, mole %
3
- l. Cavity 0.0-0.5 34.8 i 1.7 5.7 i 0.3 48.2
- 1.8 9.9 i 1.0 0.7310.02
- 2. Cavity 0.1 - 0.6 32.1
- 0.8 1.91
- 0.05 55.3
- 1.4 9.3
- 0.5 2.43
- 0.06
- 3. Seal Table Room 1.25 - 1.75 4.7
- 0.3 8.3
- 0.8 85.4
- 0.8 0.84
- 0.09 0.22
- 0.01
- 4. Upper Dome
Background
<0.01 10.1
- 0.2 89.4
- 0.6
<0.01 0.021
- 0.002
- 5. Upper Dome 60.0 - 61.0 2.6
- 0.1 6.7 i 0.2 88.2 i 0.9 0.61 i 0.09 1.151002
- 6. Upper Dome 60.0 - 61.0 2.6
- 0.1 6.8 i 0.2 88.3 i 0.9 0.6310.09 1.1210.02
- 7. Upper Dome 60.0 - 61.0 2.5
- 0.1 6.7
- 0.1 88.5
- 0.9 0.69
- 0.09 0.98 i 0.03
- 8. Upper Dome 450.0 - 451.0 2.9
- 0.1 6.8
- 0.1 87.9
- 0.9 0.68
- 0.09 1.08 i 0.03
- 9. Upper Dome' 450.0 - 451.0 0.13
- 0.1 15.0
- 0.3 83.2
- 1.0 0.33
- 0.07 0.53 i 0.02
- 10. Upper Dome 450.0 - 451.0 2.7
- 0.1 6.9
- 0.1 87.9
- 0.9 0.62
- 0.09 01.12
- 0.03
- 11. Upper Dome' 30.0 - 31.0 1.6
- 0.1 8.5
- 0.2 87.8
- 1.0 0.48
- 0.09 0.96
- 0.03
- 12. Upper Dome 30.0 - 31.0 2.0
- 0.1 7.8
- 0.2 88.2
- 0.9 0.49
- 0.09 0.96
- 0.03
- 13. Upper Dome 30.0 - 31.0 2.0
- 0.1 8.1
- 0.2 87.7
- 0.6 0.50 i 0.09 0.98
- 0.03 tThese Bottles Leaked Im
=
a a
- c w
dh 0
N oo x
l i
l l
4 s'"
n'3 I
- c b
A oo Table A.5 Gas Bottle Analysts for IET-8 Bottle / Location Timing, sec II,, mole %
O,, mole %
N,, mole %
CO, mole %
CO,, mole %
- 1. Cevity 0.0 - 0.5 58.2 i 2.7 4.1 i 0.2 20.2 i 1.1 14.6
- 0.9 1.6
- 0.1 l
- 2. Cavity
Background
8.1
- 0.4 15.1
- 0.4 74.6
- 1.5 0.4
- 0.1 0.9
- 0.1
- 3. Cavity 60.0 - 61.0 11.2
- 0.6 14.3
- 0.3 70.5
- 1.4 2.3
- 0.2 0.65
- 0 06
- 4. Upper Dome
Background
7.3
- 0.4 15.6 i 0.4 74.8
- 1.5 0.4
- 0.1 1.05 i 0.05
- 5. Upper Dome 60.0 - 61.0 18.9 i 0.9 12.3 i 0.2 62.4
- 1.2 3.1
- 0.3 1.9
- 0.1
- 6. Upper Dome 60.0 - 61.0 17.6 i 0.9 12.4
- 0.2 63.3 i 1.3 1.1
- 0.3 2.2 A 0.1
- 7. Upper Dome 60.0 - 61.0 18.4 1 0.9 11.7
- 0.2 63.5 i 1.2 3.2
- 0.3 1.7 0.1
- 8. Upper Dome 450.0 - 451.0 18.1
- 0.9 11.6
- 0.2 63.6 i 1.2 3.3
- 0.3 1.9
- 0.1
- 9. Upper Dome' 450.0 - 451.0 7.7
- 0.4 14.9 i 0.2 71.3
- 1.0 2.710.3
!.9
- 0.1
- 10. Upper Dome 450.0 - 451.0 17.6
- 0.9 12.1
- 0.2 63.4
- 1.2 3.2
- 0.3 2.3
- 0.1
'This Bottle Leaked t
-~
Table A.6 Gas Bottle Analysis for UIA Bottle /1.ocation Timing, sec II,, mole %
O,, mole %
N,, mole %
CO, mole %
CO,, mole %
- 1. Cavity 0.0 - 1.0
- 2. Cavity 15.0 - 16.0 These Bottles Did Not Sample Due To A Timing Failure
- 3. Cavity 60.0 - 61.0
- 4. Upper Dome
Background
<0.02 0.57
- 0.02 99.0
<0.04 0.01I i 0.003
- 5. Upper Dome 60.0 - 61.0 3.4 i 0.2 0.73
- 0.03 95.0 0.64
- 0.09 0.093 i 0.005
- 6. Upper Dome 60.0 - 61.0 3.5
- 0.2 0.68
- 0.02 95.0 0.58 i 0.09 0.030
- 0.003
- 7. Upper Dome 60.0 - 61.0 3.5
- 0.2 0.70
- 0.02 95.0 0.58
- 0.09 0.067 1 0.003
- 8. Upper Dome 450.0 - 451.0 4.0
- 0.2 0.65
- 0.03 94.4 0.6910.10 0.082 1 0.004
- 9. Upper Dome' 450.0 - 451.0 4.0
- 0.2 0.58 i 0.02 94.4 0.76
- 0.11 0.106 1 0.005 y
- 10. Upper Dome 450.0 - 451.0 3.9
- 0.2 0.50
- 0.01 94.6 0.67 i 0.10 0.108
- 0.005
- 11. Upper Dome' 30.0 - 31.0 3.0
- 0.2 0.68
- 0.04 95.4 0.58
- 0.09 0.076
- 0.004
- 12. Upper Dome 30.0 - 31.0 3.2
- 0.2 0.68 i 0.02 95.3 0.5510.08 0.076 1 0.002 I3. Upper Dome 30.0 - 31.0 3.4
- 0.2 0.73
- 0.02 94.8 0.6610.10 0.087 i 0.004 I4. Upper Dome 5.0 - 6.0 3.1
- 0.5 0.41
- 0.01 95.6 0.60
- 0.2 0.051
- 0.003
- 15. Upper Dome 15.0 - 16.0 3.2 i 0.2 0.40
- 0.03 95.5 0.7I i 0.I 1 0.082 1 0.008 l
- 16. Upper Dome 30.0 - 31.0 3.6
- 0.2 0.46
- 0.02 94.9 0.78
- 0.12 0.102 i 0.006
- 17. Upper Dome 60.0 - 61.0 3.7
- 0.5 0.41
- 0.04 95.0 0.67
- 0.10 0.099 i 0.004
- 18. Upper Dome 450.0 - 451.0 3.5
- 0.2 0.40 i 0.02 95.1 0.72
- 0.11 0.099 i 0.004 0
k h 'These Bottles Leaked
- c 5
Nx
Table A.7 Cas Bottle Analysis for U1B k
N tn 8
a 13ottle/ Location Timing, sec H,, mole %
O,, mole %
N,, mole %
CO, mole %
CO,, mole %
y m&
A E.
I. Cavity 0.0 - 1.0 c
- 2. Cavity 15.0 - 16.0 These Bottles Leaked
- 3. Cavity 60.0 - 61.0
- 4. Upper Dome
Background
<0.01 0.47
- 0.01 99.0
- 0.3
<0.01 0.01101 0 003
- 5. Upper Dome 60.0 - 61.0 4.3
- 0.3 0.315
- 0.008 94.2
- 0.7 0.67
- 0.10 0.113
- 0.006
- 6. Upper Dome 60.0 - 61.0 4.1
- 0.3 0.405
- 0.008 94.3
- 0.7 0.68 i 0.10 0.105 i 0.006
- 7. Upper Dome 60.0 - 61.0 4.2
- 0.3 0.363
- 0.008 94.3
- 0.7 0.70 i 0.10 0.104 1 0.006
- 8. Upper Dome 450.0 - 451.0 4.4
- 0.3 0.334
- 0.008 94.1 i 0.7 0.6610.10 0.144 1 0.007
- 9. Upper Dome 450.0 - 451.0 4.9
- 0.3 0.303
- 0.008 93.7
- 0.7 0.74
- 0.10 0.093 1 0.005 y
- 10. Upper Dome 450.0 - 451.0 4.6
- 0.3 0.32
- 0.008 93.9
- 0.7 0.69
- 0.10 0.112
- 0.006
- 11. Upper Dome' 30.0 - 31.0 0.03
- 0.01 15.7
- 0.3 83.2
- 0.5 0.20
- 0 09 0.053
- 0.003
- 12. Upper Dome 30.0 - 31.0 4.2
- 0.2 0.48I i 0.007 94.3
- 0.7 0.58
- 0.09 0.089 i 0.004
- 13. Upper Dome 30.0 - 31.0 4.0
- 0.2 0.443
- 0.009 94.5
- 0.5 0.61
- 0. I I 0.087
- 0.003 E I4. Upper Dome 5.0 - 6.0 4.4
- 0.3 0.184
- 0.004 94.4 i 0.5 0.57 i 0.IO 0.112 1 0.005 l
- 15. Upper Dome 15.0 - 16.0 4.5
- 0.2 0.228
- 0.005 94.1
- 0.5 0.62 i 0.09 0.I16 1 0.005
- 16. Upper Dome 30.0 - 31.0 4.2
- 0.3 0.235 i 0.005 94.5
- 0.6 0.54 i 0.08 0.107 i 0.006
- 17. Upper Dome 60.0 - 61.0 4.2
- 0.3 0.185
- 0.004 94.7
- 0.5 0.58
- 0.10 0.102 1 0.005
- 18. Upper Dome 450.0 - 451.0 4.8
- 0.3 0.160
- 0.003 94.1
- 0.5 0.62
- 0.09 0.108
- 0.004
'This Bottic Leaked I
ll
Table A.8 Cas Bottle Analysis for U2 13ottle/ Location Timing, see H,, mole %
0, mole %
N,, mole %
CO, mole %
CO,, mole %
3
- l. Cavity' O.0 - 1.0 0.03
- 0.01 17.2
- 0.5 77.3
- 0.7 0.46
- 0.09 0.084 i 0.008
- 2. Cavity I5.0 - 16.0 5.4
- 0.3 9.9
- 0.2 74.5
- 0.9 4.310.9 1.6
- R I
- 3. Cevity 60.0 - 61.0 18.2
- 1.1 8.1
- 0.2 65.6
- 0.8 2.9
- 0.4 1.11
- 0.06
- 4. Upper Dome'
Background
2.1
- 0.1 13.0
- 0.3 83.7
- 0.6 0.03
- 0.03 0.012
- 0.004
- 5. Upper Dome 13ackground 2.6
- 0.1 11.6
- 0.3 84.6
- 0.6 0.07 0.04 0.01I
- 0.004
- 6. Upper Dome 60.0 - 61.0 2.6
- 0.I 9.2
- 0.2 86.3
- 0.6 0.43
- 0.09 0.36
- 0.02
- 7. Upper Dome 60.0 - 61.0 2.6
- 0.1 9.5
- 0.2 86.I
- 0.6 0.41
- 0.08 0.33
- 0.02
- 8. Upper Dome 450.0 - 451.0 2.4
- 0. I 9.3
- 0.2 86.4
- 0.6 0.40
- 0.08 0.34 i 0.02 y
- 9. Upper Dome 450.0 - 451.0 2.4
- 0.1 10.3
- 0.3 85.4
- 0.7 0.40
- 0.08 0.36
- 0.02 l
- 10. Upper Dome 450.0 - 451.0 2.6
- 0.1 9.4
- 0.2 86.0
- 0.6 0.44
- 0.10 0.36
- 0.02 i
I1. Upper Dome 310-31.0 2.5
- 0.2 10.6
- 0.3 85.3
- 0.8 0.1I i 0.05 0.31
- 0.03 j
- 12. Upper Dome 30.0 - 31.0 2.4
- 0.1 10.2
- 0.3 85.6
- 0.6 0.26
- 0.06 0.32 i 0.02
- 13. Upper Dome 30.0 - 31.0 2.4
- 0.2 10.4
- 0.4 85.6
- 0.9
<0.1 0.32
- 0.03 l
- 14. Upper Dome 5.0 - 6.0 3.1
- 0.2 8.0
- 0.2 87.0
- 0.6 0.38 i 0.08 0.45 t 0.02
- 15. Upper Dome 15.0 - 16.0 3.0
- 0.2 7.9 i 0.2 87.2
- 0.6 0.39 i 0.10 0.46
- 0.03
- 16. Upper Dome 30.0 - 31.0 2.9
- 0.3 8.2
- 0.3 87.1
- 0.9 0.31
- 0.10 0.45
- 0.03
- 17. Upper Dome 60.0 - 61.0 2.7
- 0.2 7.8
- 0.2 87.7
- 0.7 0.26
- 0.08 0.45
- 0.03
- 18. Upper Dome 450.0 - 451.0 2.8
- 0.2 8.2 i 0.2 87.4
- 0.6 0.20
- 0.08 0.37
- 0.02 O
Q 'These Bottles Leaked 5
Nx
_ _ _ _ _ _ _ - - _ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ = _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
C 70mv 335 U.S. NUCLE AR PEGULATORY COMMISSION 1.
P T N' f ER NmCY 11C2.
saa Accenaam Numters, if say.)
2 m 32:2 BIBLIOGRAPHIC DATA SHEET rs,,,ntr,scr,ons on tne r,<, rue NUREG/CR-6168
- 2. tit tE ANo SveT'T'E ANL-94/18 Direct Containment Heating Integral Effects Tests at 1/40 Scale in Zion Nuclear Power Plant Geometry
' ' ' " " "* "'[S"[
September '
1994
- 6. TYPE Of REPORT J.L. Binder, L.M. Mcumber, B.W. Spencer Technical
- 7. PE R IOD COV E R E D isavus-e cerm
- C,h"l3a"?'~,i.lHl*"~~"""'^~***"'"'"~"'"*"**"'""'"'"*"'"'"'""'*"""*"'"""'"'""**"'"'"'""""""'**'*"'""
s Argonne National Laboratory 9700 S. Cass Avenue Argonne, IL 60439
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Division of Systems Research Office of Nuclear Regulatory Research U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 to SUPPLEMENTARY NOTES
- 11. ABST R ACT /200 =.ms o, kso The results of Direct Containment Heating (DCH) integral experiments are presented. The experiments sinulated a high pressure melt ejection in the Zion Nuclear Power Plant.
Experiments were conducted in a 1/40 Scale model of the Zion containment.
The model included the vessel lower head, cavity and instrument tunnel, and the lower containment structures. The melt ejections were driven by steam.
There were two main objectives of these experiments.
The first was to investigate the effect of scale on DCH phenomena. The IET test series addressed this by conducting counterpart integral tests in a 1/40 scale facility at Argonne National Laboratory and in a 1/10 scale facility at Sandia National Laboratories.
Iron / alumina thermite with chromium was used as a core melt simulant in the IET test series. The second objective was to address potential experiment distortions introduced by the use of non-prototypic iron / alumina thermite.
The second objective was met in the U series of tests which utilized a prototypic core melt.
Corium experiments were conducted that were counterpart to the IET-1RR and IET-6 iron / alumina tests.
- 12. AE Y WORDS 'OESCR PTORS Ost wor.s.rparem re r -di mst res,arr*
- er rocarra rne repon s a a v AtL Afu Ld v ST AitMENT e
Unlimited Direct Containment Heating (DCH) i 5 ice, ct Ass:nce,%
Zion Nuclear Power Plant
,r,,,,,,,,,
Severe Accident Unclassifiad (Thos Rep rt)
Uncl a s si fi ed Ib. NUMBER OF PAGE S
- 16. PRICE NRC F OAv 33$ G49
\\
Sb Federal Recycling Program
IN ZION NUCI. EAR POWER PIANT GEOMETRY UNITED STATES SPECIAL FOURTH CLASS RATE NUCLEAR REGULATORY COMMISSION POSTAGE AND FEES PAiO WASHINGTON. D.C. 20555 0001 USNAC PE RVti NO G C1 OFflCIAL BUSINESS PEN ALTY FOR PR!VATE USE. $300
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