RBHT Reflood Heat 

Transfer Experiments 

Data and Analysis

Office of Nuclear Regulatory Research

NUREG/CR-6980
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RBHT Reflood Heat

Transfer Experiments

Data and Analysis

Manuscript Completed: January 2011 

Date Published: April 2012 

Prepared by:

L. E. Hochreiter

Fan-Bill Cheung

T. F. Lin

J. P. Spring

S. Ergun

A. Sridharan

A. Ireland

E. R. Rosal (Applied Research Laboratory)

The Pennsylvania State University

University Park, PA 16802

K. Tien, NRC Project Manager

NRC Job Code N6154

Office of Nuclear Regulatory Research 

NUREG/CR-6980

iii 

ABSTRACT 

A total of 25 valid bottom reflood heat transfer experiments have been performed in the 

Pennsylvania State University/U.S. Nuclear Regulatory Commission Rod Bundle Heat Transfer 

(RBHT) Test Facility to examine the effects of both dispersed flow film boiling and inverted 

annular film boiling in rod bundle geometry. The RBHT Test Facility had a full length, 3.66 m 

(12 ft), 7x7 rod array with typical pressurized water reactor rod diameters of 9.49 mm (0.374 in) 

and a rod pitch of 12.59 mm (0.496 in). The heater rods had a top skewed power shape with a 

peak to average power of 1.5 at the 2.77 m (9.08 ft) elevation. The ranges of conditions for the 

experiments were pressures from 138 to 414 kPa (20 to 60 psia), flooding rates from 0.0254 to 

0.1524 m/s (1 to 6 in/s), and initial peak clad temperatures from 1033 to 1144 degrees K (1400 

to 1600 degrees F), inlet subcooling from 11 to 83 degrees K (20 to 150 degrees F), and peak 

powers of 1.32 to 2.31 kW/m (0.4 to 0.7 kW/ft). The experiments were performed using a 

constant power rather than simulating the reactor decay power. The use of a constant bundle 

power extended the reflood transient several hundred seconds and resulted in quasi-steady film 

boiling over the majority of the bundle length. There were approximately 500 channels of 

transient data recorded for each test including the bundle power, heater rod temperatures, 

upper plenum pressure, inlet flow rate, inlet water subcooling, superheated vapor temperatures 

in the bundle, spacer grid temperatures, liquid carryover of the bundle, and the detailed axial 

bundle pressure drop. Transient mass balances were typically within five percent for the low 

flooding rate experiments, and larger for the higher flooding rate experiments. The experimental 

data has been qualified and submitted to the U.S. Nuclear Regulatory Commission data bank 

for analysis and computer code validation. 

v 

FOREWORD 

Reflood thermal-hydraulics represents an important set of phenomena during a hypothetical 

large break loss-of-coolant-accident (LOCA). These phenomena must be accurately simulated 

by systems codes in determining plant response to a LOCA. In spite of significant research into 

reflood thermal-hydraulics, there still exists a large uncertainty in these calculations. As a result, 

the Nuclear Regulatory Commission (NRC) conducts experimental investigations of reflood 

thermal-hydraulics in order to provide data for model development and to more thoroughly 

assess its systems codes. 

The NRC is currently assessing and improving the TRAC/RELAP Computational Engine 

(TRACE) code for best estimate analysis of light water reactors. While calculation of reflood by 

TRACE appears to be reasonable, higher accuracy is needed as the code is applied to power 

uprates and new plant designs to ensure acceptable margin between expected plant 

performance and the regulatory limits. Accurate prediction of the consequences of a large 

break LOCA is important because it is one of the postulated accident scenarios that determine 

the licensed core power and several other operational parameters. As the NRC places greater 

emphasis on risk-informed regulation, a more accurate and reliable systems code is needed to 

obtain realistic rather than conservative predictions. 

To acquire detailed, fundamental data for use in developing models for an LBLOCA, the NRC 

sponsored the design and construction of a Rod Bundle Heat Transfer (RBHT) Test Facility. 

Some of these detailed data have only recently become possible because of recent advances in 

instrumentation technology for two-phase flow measurements. 

This report presents the results of reflood heat transfer tests. The data from these tests will be 

used to develop and assess a reflood model for the TRACE code. The results of other test 

series will be reported in separate reports. Additional information about the RBHT Test 

Program is provided in two previously published reports: NUREG/CR-6975, “Rod Bundle Heat 

Transfer Test Facility Test Plan and Design,” and, NUREG/CR-6976, “Rod Bundle Heat 

Transfer Test Facility Description.” 

With improved data and code models for an LBLOCA, we can more accurately predict the 

consequences of LBLOCA accidents and provide better technical bases for regulations 

associated with such accidents. As a result, this study will help to achieve the NRC’s strategic 

performance goals of making the agency’s regulations more effective, efficient, and realistic. 

 

 

vii 

CONTENTS 

Page

ABSTRACT ................................................................................................................................ iii

FOREWORD ............................................................................................................................... v

EXECUTIVE SUMMARY .......................................................................................................... xiii

ABBREVIATIONS ..................................................................................................................... xv

1. INTRODUCTION .................................................................................................................... 1

1.1 Rod Bundle Heat Transfer Program Reflood Heat Transfer Test Matrix ......................... 3

1.2 References ...................................................................................................................... 3

2. TEST FACILITY DESCRIPTION FOR REFLOOD EXPERIMENTS ....................................... 7

2.1 General Facility Description ............................................................................................. 7

2.1.1 Test Section .............................................................................................................. 9

2.1.2 Lower Plenum ......................................................................................................... 16

2.1.3 Upper Plenum ......................................................................................................... 16

2.1.4 Large and Small Carryover Tanks ........................................................................... 18

2.1.5 Steam Separator and Collection Tank ..................................................................... 21

2.1.6 Pressure Oscillation Damping Tank ........................................................................ 22

2.1.7 Exhaust Piping ........................................................................................................ 24

2.1.8 Injection Water Supply Tank ................................................................................... 25

2.2 Facility Improvements Over Previous Tests .................................................................. 26

2.3 Instrumentation and Data Acquisition System ............................................................... 26

2.3.1 Loop Instrumentation and Controls ......................................................................... 27

2.3.2 Test Section Instrumentation ................................................................................... 29

2.3.3 Data Acquisition System .......................................................................................... 38

3. CALCULATIONAL METHODS USED FOR THE RBHT REFLOOD HEAT TRANSFER 

EXPERIMENTS .................................................................................................................. 40

3.1 Transient Heat Transfer Coefficient Calculation (DATARH) .......................................... 40

3.1.1 Introduction .............................................................................................................. 40

3.1.2 Mathematical Model ................................................................................................ 40

3.1.3 Structure of the source program DATARH.F ........................................................... 45

3.1.4 RBHT Rod Geometry and Materials ........................................................................ 47

3.1.5 Input File Required for Executing the Current Version of the Program ................... 48

3.1.6 Calculation of the Power Factor at Each Thermocouple Location ........................... 51

3.2 Quench Front Determination ......................................................................................... 57

3.3 RBHT Mass Balance .....................................................................................................65

3.3.1 Introduction .............................................................................................................. 65

3.3.2 Methodology ............................................................................................................ 65

3.3.3 Summary of Mass Imbalances ................................................................................ 67

3.3.4 Transient Mass Balance .......................................................................................... 68

3.3.5 Mass Storage in the Bundle .................................................................................... 70

3.4 Droplet Measurements ..................................................................................................73

3.4.1 Droplet Measurement Instrumentation .................................................................... 73

3.4.2 Droplet Size Measurements .................................................................................... 75
viii 

3.4.3 Droplet Size and Elevation ...................................................................................... 75

3.4.4 Droplet Velocity ....................................................................................................... 82

3.4.5 Calculation of Interfacial Area from Droplet Distribution Data ................................. 83

3.4.6 Droplet Measurement Data for Individual Experiments ........................................... 85

3.5 References ..................................................................................................................... 86

4. CONCLUSIONS .................................................................................................................... 88

APPENDIX A. TEST RESULTS ............................................................................................. A-1

APPENDIX B. UNCERTAINTIES .......................................................................................... B-1

B.1 Measurement Errors .................................................................................................... B-1

B.2 Heat Transfer Coefficient Uncertainty Analysis ........................................................... B-8

B.3 References ................................................................................................................ B-24
ix 

FIGURES

Page

1.1 Reflood Flow Regimes for High and Low Reflood Rates . ............................................ 2

2.1 RBHT Test Facility Schematic . .................................................................................... 8

2.2 Test Facility Isometric View . ........................................................................................ 8

2.3 Test Section Isometric View . ...................................................................................... 11

2.4 Rod Bundle Cross Section View . ............................................................................... 12

2.5 Heater Rod Schematic . .............................................................................................. 13

2.6 Heater Rod Axial Power Profile .................................................................................14

2.7 Mixing Vane Grid ....................................................................................................... 14

2.8 Low Melt Reservoir .................................................................................................... 15

2.9 Housing Window ........................................................................................................ 15

2.10 Lower Plenum ............................................................................................................ 17

2.11 Upper Plenum ............................................................................................................ 17

2.12 Exhaust Line Baffle .................................................................................................... 18

2.13 Small Carryover Tank ................................................................................................ 19

2.14 Large Carryover Tank ................................................................................................ 20

2.15 Steam Separator ........................................................................................................ 21

2.16 Steam Separator Collection Tank .............................................................................. 22

2.17 Pressure Oscillation Damping Tank ........................................................................... 23

2.18 Exhaust Piping ........................................................................................................... 24

2.19 Injection Water Supply Tank ...................................................................................... 25

2.20 Loop Instrumentation Schematic ............................................................................... 28

2.21 Rod Bundle and Housing Instrumentation Axial Locations ........................................ 30

2.22 Instrumented Heater Rod Radial Locations ............................................................... 31

2.23 Mixing Vane Grid Instrumentation .............................................................................. 31

2.24 Grid No. 2 Instrumentation ......................................................................................... 32

2.25 Grid No. 3 Instrumentation ......................................................................................... 32

2.26 Grid No. 4 Instrumentation ......................................................................................... 33

2.27 Grid No. 5 Instrumentation ......................................................................................... 33

2.28 Grid No. 6 Instrumentation ......................................................................................... 34

2.29 Grid No. 7 Instrumentation ......................................................................................... 34

2.30 Traversing Steam Probe Rake Schematic ................................................................. 36

2.31 Laser Illuminated Digital Camera System Setup ....................................................... 37

3.1 RBHT Test Facility, Heater Rod Locations (Looking Down from Top) ....................... 51

3.2 Axial Power Ratio for Rod F4 ..................................................................................... 52

3.3 Power Factor as a Function of Length (Beginning of Heated Length to PCT) ........... 54

3.4 Power Factor as a Function of Length (From PCT to End of Heated Length) ........... 54

3.5 Clad Temperature at 2.24 m, Experiment 1096 ......................................................... 57

3.6 Temperature and First Derivative of Temperature at 2.24 m Elevation ..................... 59

3.7 Temperature and First Derivative of Temperature Curve at 2.42 m Elevation ........... 60

3.8 Temperature and First Derivative of Temperature Curve at 2.42 m Elevation ........... 61

3.9 Quench Temperature at Different Quench Locations, Experiment 1096 . .................. 62

3.10 Quench Temperature at Different Quench Locations, Experiment 1383 ................... 63

3.11 Housing Quench Front, Experiment 1096 .................................................................. 63

3.12 Housing Quench Front, Experiment 1383 .................................................................. 64

3.13 Rod and Housing Quench Front, Experiment 1096 ................................................... 64

3.14 Rod and Housing Quench Front, Experiment 1383 ................................................... 65
x 

3.15 Summary of Mass Imbalances ................................................................................... 68

3.16 Supply Tank Cross-Sectional Area ............................................................................ 69

3.17 Mass Balance Plot for Experiment 1383 .................................................................... 72

3.18 General Schematic of the Imaging System ................................................................ 74

3.19 Typical VisiSizer Image Through the Rod Bundle (No Droplets Present) .................. 74

3.20 Normalized Droplet Distributions Upstream and Downstream Grid ........................... 76

3.21 Probability Distribution Log-Normal Curve Fits Upstream and Downstream Grid ...... 77

3.22 Drop Breakup Data as a Function of Droplet Impact Weber Number . ....................... 78

3.23 Comparison of Droplet Diameters .............................................................................. 79

3.24 Comparison of Droplet Diameters .............................................................................. 80

3.25 Comparison of Droplet Diameters ............................................................................. . 81

3.26 Size and Velocity Distribution Downstream of the Spacer Grid ................................. 82

3.27 Sauter Mean Diameter Time History for Experiment 1383 ........................................ 84

3.28 Liquid Flow rate for Experiment 1383 ........................................................................ 85

3.29 Rate of Interfacial Area for Experiment 1383 ............................................................. 86

 
xi 

TABLES 

Page

1.1 Reflood Heat Transfer Test Log ................................................................................... 4

3.1 Geometry and Dimensions of RBHT Heater Rod ...................................................... 47

3.2 Heater Number 1 ....................................................................................................... 51

3.3 Sample Power Factor Calculation for One Heater Rod ............................................. 53

3.4 Axial Power Factors for the RBHT Heater Rods ........................................................ 55

3.5 Supply Tank Parameters ........................................................................................... 68

 

xiii 

EXECUTIVE SUMMARY 

As part of the U.S. Nuclear Regulatory Commission’s safety analysis computer code 

development efforts, the Rod Bundle Heat Transfer (RBHT) Test Facility has been designed 

and constructed at The Pennsylvania State University. The RBHT Test Facility is a full length 

simulation of a portion of a pressurized water reactor (PWR) fuel assembly. The bundle is a 7x7 

rod array with four unheated corner rods and 45 heated electrical rod which simulate a 17x17 

PWR fuel assembly. The RBHT Test Facility has a heated length of 3.66 m (12 ft), with typical 

PWR rod diameters of 9.49 mm (0.374 in) and a rod pitch of 12.6 mm (0.496 in). The heater 

rods have a top skewed power shape with a peak to average power of 1.5 at the 2.77 m (9.08 ft) 

elevation. The ranges of conditions for the experiments are pressures from 138 to 414 kPa (20 

to 60 psia), flooding rates from 0.0254 to 0.1524 m/s (1 to 6 in/s), and initial temperatures from 

1033 to 1144 degrees K (1400 to 1600 degrees F), inlet subcooling from 11 to 83 degrees K (20 

to 150 degrees F), and peak powers of 1.32 to 2.31 kW/m (0.4 to 0.7 kW/ft). Typical PWR 

mixing vane spacer grids were simulated in the RBHT bundle. 

There are approximately 500 channels of transient data recorded for each test including the 

bundle power, heater rod temperatures, upper plenum pressure, inlet flow rate, inlet water 

temperature, superheated vapor temperatures in the bundle, spacer grid temperatures, liquid 

carryout of the bundle, and the detailed axial bundle pressure drop. Transient mass balances 

were typically within five percent for the low flooding rate experiments, and larger for the higher 

flooding rate experiments. There are a total of 25 valid experiments performed and reported to 

the U.S. Nuclear Regulatory Commission. The data from these experiments were qualified and 

submitted to the U.S. Nuclear Regulatory Commission’s data bank for analysis and code 

validation purposes. 

There are several unique features of the RBHT program which are not found in other rod bundle 

reflood heat transfer experiments. The RBHT experiments are performed using constant power 

rather than simulating decay power as in previous rod bundle experiments. The use of constant 

power results in a quasi-steady dispersed flow film boiling regime in the bundle and extends the 

reflood transient. The longer experimental time allows a more detailed examination of the 

dispersed flow film boiling heat transfer models in the analysis codes without the additional 

complication of a rapidly moving quench front up the bundle. There are traversing miniature 

steam probes in the bundle at several elevations which measured the superheated steam 

temperature in the presence of saturated entrained droplets. The steam probes are located upand downstream of the spacer grids and can indicate the effects of the spacer grids on the twophase droplet flow. There is also a laser illuminated high resolution digital camera and 

associated software which can measure the entrained droplet size within the bundle at different 

elevations relative to the spacer grids. There are a large number of very sensitive differential 

pressure cells along the bundle. The mixing vane grids are also instrumented with several 

miniature thermocouples such that spacer grid temperature behavior can also be characterized 

in addition to the heater rod and vapor temperature measurements. The RBHT Test Facility 

reflood heat transfer experiments have provided integrated detailed data that can be used for 

advanced safety analysis computer code assessment for dispersed flow film boiling and 

inverted annular film boiling in a prototypical rod bundle geometry. 

xv 

ABBREVIATIONS 

DATARH Data Reduction and Heat Transfer Computer Program 

ECC Emergency Core Cooling 

FLECHT Full-Length Emergency Core Heat Transfer 

FLECHT-SEASET Full-Length Emergency Core heat Transfer – Separate Effects and 

 System Effects Tests 

HP Hewlett-Packard 

IEEE Institute of Electrical and Electronics Engineers 

INEEL Idaho National Engineering and Environmental Laboratory 

LBLOCA Large-Break Loss of Coolant Accident 

LIDCS Laser Illuminated Digital Camera System 

NRC U.S. Nuclear Regulatory Commission 

PWR Pressurized Water Reactor 

TC Thermocouple 

RBHT Rod Bundle Heat Transfer 

SMD Sauter Mean Diameter 

STP Standard Temperature and Pressure Conditions 

1 

INTRODUCTION 

 

The objective of the Rod Bundle Heat Transfer (RBHT) Program is to provide high quality 

experimental data for computer code model development and validation. As part of this 

program, a series of experiments are performed to examine reflood thermal/hydraulic behavior 

over a wide range of conditions. 

A series of reflood experiments are performed in the (RBHT) facility over a range of pressures, 

flow rates, inlet temperatures and simulated powers. The experiments are run using constant 

power, which is different from the previously performed FLECHT (Refs. 1 and 2) and FLECHTSEASET (Ref. 3) experiments such that the reflooding behavior is quasi-steady for much longer 

periods of time. It is believed that the quasi-steady behavior of the RBHT experiments will make 

model development and validation easier since the film boiling portions of the experiments are 

extended in time. Also, the specific instrumentation which was added to the RBHT for improved 

understanding of the reflooding process will provide new and improved data for the quasi-steady 

reflood experiments. Specifically, subchannel vapor measurements using miniature 

thermocouples on traversing steam probe rakes yield vapor superheat for extended times as the 

quench front advances up the heater rods. 

There are two basic flow regimes for reflooding in a rod bundle. For high flooding rates, 

typically, 0.1524 m/s (6 in/s) or higher, the dominant flow regime for the post-CHF regions in the 

bundle is an inverted annular regime in which a thin layer of vapor separates the heated wall 

from the subcooled liquid flow which nearly fills the channel. Since the inlet flow is larger than 

the quench rate of the fuel rods, a long region of inverted film boiling can exist above the 

quench front. As one proceeds upward along the bundle, liquid becomes saturated and begins 

to break into chunks or liquid slugs. The length of the inverted annular and the liquid chunk 

regimes depends on the flooding rate into the heated bundle, initial subcooling of the liquid, 

system pressure, and the rod bundle initial temperature and power level. The heat transfer in 

this regime is high and results in immediate clad temperature turnover such that lower peak 

cladding temperatures are calculated for this reflood regime. Figure 0.1 shows an example of 

both the high and low flooding rate reflood heat transfer and flow regimes. 

For low flooding rates, there is no subcooled inverted annular film boiling region. Because of 

the low injection flow rate, the liquid quickly reaches saturation and there is bulk boiling of the 

fluid below the quench front. In the quench front region, and above the quench front, there is a 

froth region which has a medium range void fraction which transitions between a low void 

fraction, below the quench front, to the much higher void fraction in the dispersed flow regions 

above the quench front. This behavior is shown in Figure 0.1. The heat transfer in this region 

occurs between the heated wall and the superheated steam. Liquid droplets in the superheated 

steam evaporate reducing the steam temperature as well as increasing the flow rate of the 

steam. As a result, the calculated peak cladding temperature usually occurs in this region. In 

most reactor reflood calculations, after the initial surge into the core, the flooding rates are very 

low, typically 0.0254 m/s (1 in/s) or less such that the dispersed flow film boiling region is the 

dominant flow regime of interest and is the heat transfer regime in which the peak cladding 

temperature occurs. 
2 

Figure 0.1 Reflood Flow Regimes for High and Low Reflood Rates. 

The RBHT instrumentation strategy is primarily designed to obtain detailed information for the 

low flooding rate experiments. The low flooding rate conditions are more limiting for postulated 

accident conditions, and the phenomena associated with the low flooding rate behavior are 

more difficult to predict with accuracy. 

This report provides a summary of the data obtained, the data reduction methods and 

assumptions used in reducing the data as well as the uncertainty in the experimental data and 

derived quantities from the data. A full set of the experimental data was transmitted to the NRC 

data bank. 

 
3 

1.1 Rod Bundle Heat Transfer Program Reflood Heat Transfer Test Matrix

A series of reflood heat transfer experiments are performed to provide data for dispersed flow 

film boiling in rod bundles as well as for the inverted annular flow film boiling heat transfer 

regime. The range of pressures expected during a PWR LBLOCA was examined as well as the 

inlet subcooling of the Emergency Core Cooling (ECC) flow into the test bundle. The initial 

temperatures are selected to represent a Best-Estimate peak cladding temperature at the 

beginning of the reflood portion of the LOCA transient. Most of the experiments use a peak 

cladding temperature of 1033 to 1144 degrees K (approximately 1400 degrees F). The flooding 

rates vary from 0.0254 to 0.1524 m/s (1 to 6 in/s). 

There are a number of repeat experiments in which the laser illuminated digital camera system 

is moved to different axial positions in the rod bundle. The strategy is to obtain drop size 

information at different elevations, relative to the quench front, for the same system conditions 

such that the evolution of the entrained flow can be determined by super-positioning the data 

gathered in different experimental runs. 

While there is a learning curve in performing the experiments, the test repeatability, mass 

balances, and test performance continued to improve over the testing period. The most 

significant problem encountered in the reflood test series is pressure oscillations which occurred 

due to the control logic for the exhaust control valve. Pressure variations in the test section 

were usually small, but there are several experiments in which pressure oscillations could not 

be damped and the experimental runs are considered invalid. The reflood heat transfer test log 

is given in Table 1.1 for the different experiments performed and there is a Quick Look Report 

(QLR) written for each valid experiment which contains a mass balance calculation. The data 

from these experiments has been sent to the NRC’s data bank in electronic format. 

1.2 References

1. Rosal, E. R., Hochreiter, L. E., McGuire, M. F., Krepinevich, M. C., “FLECHT Low 

 Flooding Rate Cosine Test Series Data Report,” WCAP-8651, December (1975). 

2. Rosal, E. R., Conway, C. E., Krepinevich, M. C., “FLECHT Low Flooding Rate Skewed Test 

 Series Data Report,” WCAP-9108, May (1977). 

3. Lee, N., Wong, S., Yeh, H.C., and Hochreiter, L.E., “PWR FLECHT-SEASET Unblocked 

 Bundle, Forced and Gravity Reflood Task Data Evaluation & Analysis Report,” 

 NRC/EPRI/Westinghouse Report No. 10, WCAP-9891, NUREG/CR-2256, EPRI NP-2013, 

 November (1981). 

 
4 

Table 1.1 Reflood Heat Transfer Test Log 
5 

Table 1.1 Reflood Heat Transfer Test Log (Cont) 
6 

Table 1.1 Reflood Heat Transfer Test Log (Cont) 
7 

2. TEST FACILITY DESCRIPTION FOR REFLOOD EXPERIMENTS 

The RBHT Test Facility was developed by The Pennsylvania State University and the United 

States Nuclear Regulatory Commission. The facility is designed to conduct systematic separate 

effects tests under well-controlled laboratory conditions in order to generate fundamental rod 

bundle heat transfer data from: two-phase level swell tests, steam flow tests with and without 

droplet injection, inverted annular film boiling reflood tests, and dispersed flow film boiling 

reflood heat transfer tests. The facility is capable of operating in steady-state forced and 

variable reflood modes covering a wide range of flows and heat transfer conditions at pressures 

from 1.0 (14.5 psia) to 4.2 bars (60 psia). 

2.1 General Facility Description

The test facility consists of the following major components shown schematically in Figure 2.1, 

and in an isometric view in Figure 2.2: 

• A test section consisting of a lower plenum, a low-mass housing containing the heater 

rod bundle, and upper plenum. 

• Coolant injection and steam injection systems. 

• Closely coupled phase separation and liquid collection systems. 

• An injection system. 

• A pressure fluctuation damping tank and steam exhaust piping. 

The test facility is a once-through flow facility in which either water or steam can enter the lower 

plenum and flow upward through the rod bundle. The lower plenum is attached to the bottom of 

the flow housing and is used as a reservoir for the coolant prior to injection into the rod bundle 

during reflood. The upper plenum serves as the first stage for phase separation and liquid 

collection of the two-phase effluent exiting the rod bundle. The liquid phase separates from the 

flow due to the sudden expansion from the bundle to the larger plenum flow area. 

The facility has a large and small liquid carryover tank provided to collect the liquid carryover in 

order to measure the amount of entrainment in the flow. The de-entrained liquid from the upper 

plenum drains into the top of a 25.6 mm tube, which extends inside the small carryover tank. 

When the small carryover tank fills, it overflows into the large carryover tank. A centrifugal twophase separator is located downstream of the upper plenum and acts to separate out the 

remaining liquid flow from the vapor such that the vortex meter at the exit of the steam pipe will 

measure single phase vapor flow only. There is a third liquid collection tank on the phase 

separator, which collects the separated liquid. 

A pressure-damping tank located before the vortex flow meter and pressure control valve acts 

to damp out any pressure oscillations to maintain tight pressure control on the facility. 

Separating the exit flows from the bundle provides a means of calculating a transient mass 

balance as well as an energy balance on the facility. 
8 

Figure 2.1 RBHT Test Facility Schematic. 

Figure 2.2 Test Facility Isometric View. 

EXIT 

FLOWMETER

EXHAUST 

MUFFLER 

EXHAUST 

VALVE

LOWER PLENUM 

7X7 ROD BUNDLE 

FLOW HOUSING 

UPPER 

PLENUM 

PRESSURE 

OSCILLATION 

DAMPING TANK 

HEATED 

WATER 

SUPPLY 

TANK 

INLET 

FLOWMETER 

STEAM 

SEPERATOR 

CARRY OVER 

TANK 

LOW MELT 

RESERVOIR AND 

CONNECTOR 

PLATE
9 

2.1.1 Test Section 

The test section consists of the heated rod bundle, flow housing, and the lower and upper 

plenums, as shown in Figure 2.3. The heater rod bundle simulates a small portion of a 17x17 

PWR reactor fuel assembly. The electrically powered heater rods have a diameter of 9.5 mm 

(0.374 in) arranged in a 7x7 array with a 12.6 mm (0.496 in) pitch, as shown in Figure 2.4. The 

bundle has 45 heater rods and 4 unheated corner rods. The corner rods are used to provide 

structural support for the bundle and provide exit points for thermocouple leads. The support 

rods are made from Inconel 600 tubing having a diameter 9.525 mm (0.37 in), a wall thickness 

of 2.108 mm (0.083 in), and a total length of 3.96 m (156 in). The heater rods are single ended 

and consist of a Monel 500 electrical resistance heating element surrounded by hot pressed 

boron nitride (BN) insulation and enclosed in a Inconel 600 cladding, as shown in Figure 2.5. 

Since it is desired to re-use the heater rods for multiple experiments, the cladding material was 

chosen for its high strength and low thermal expansion coefficient at high temperatures, which 

minimizes rod bowing and failure at high temperature operating conditions. The heater rods 

have a 3.66 m (12 ft) heated length with a skewed axial power profile, as shown in Figure 2.6, 

with the peak power located at the 2.74 m (9 ft) elevation. The maximum-to-average power 

ratio (Pmax/Pavg) is 1.5 at the peak power location and 0.5 at both ends of the heated length. The 

bundle has a uniform radial power distribution. 

Power to each rod is provided by a 60 volt, 12,600 amp, 750 kW DC power supply. Each rod is 

rated for 10 kW, and designed to operate at 13.8 bars (200 psig) at a maximum temperature of 

1477 degrees K (2200 degrees F), but because of its solid construction it can be operated up to 

103.4 bars (1500 psig). Rods marked with an “I” in Figure 2.4 are instrumented with eight 0.508 

mm (0.02 in) diameter ungrounded thermocouples attached to the inside surface of the Inconel 

sheath at various locations. Rods marked with a “U” are not instrumented. All of the 

thermocouple leads exit at the heater rod bottom end. The Inconel 600 thermocouple sheath is 

compatible with the heater rod cladding and housing material to reduce differential thermal 

expansion and minimize the possibility of causing thermocouple failure during the thermocycling operations. 

The rod bundle has seven mixing vane grids shown in Figure 2.7. These grids are similar in 

design of a PWR 17x17 fuel assembly, but instead of having dimples and springs, these grids 

have only dimples which provide a cold clearance of 0.127 mm (0.005 in) around each heater 

rod in order to prevent bowing when the heater rods are linearly expanding at high 

temperatures. The grids straps are made out of Inconel 600 alloy sheets which are 0.51 mm 

(0.020 in) thick and are 44.5 mm (1.75 in) in height including the mixing vanes. The grids are 

located 522 mm (20.55 in) apart except for the spacing between the first and second grid, which 

is 588 mm (23.26 in) apart. The first grid is located 102 mm (4.01 in) above the bottom of the 

heater length. The grids in conjunction with the corner rods form the heater rod bundle support 

structure. The grid locations are similar to the ones found in a 17x17 PWR fuel assembly. The 

heater rod top extensions are attached to the 25.4 mm (1 in) thick nickel ground plate by means 

of a Morse taper that provides a good electrical contact. The heater rod bottom extension and 

copper electrode extend through the lower plenum O-ring pressure seal plate. 

The copper electrodes, which are 5.84 mm (0.023 in) in diameter and 203 mm (8 in) long, 

extend through holes drilled in the low-melt reservoir shown in Figure 2.8. This reservoir serves 

as the electrical power supply positive connection. It contains a low temperature melting alloy at 

about 344 degrees K (160 degrees F) which is an excellent conductor, thus providing a good 
10 

electrical contact and mechanical cushion allowing for rod thermal expansion to each heater 

rod. 

The flow housing provides the pressure and flow boundary for the heater rod bundle. It has a 

square geometry. Its inside dimensions are 90.2 x 90.2 mm (3.55 x 3.55 in), and wall thickness 

6.4 mm (0.25 in) as shown in Figure 2.4. The housing is made out of Inconel 600, the same 

material used for the heater rod cladding and thermocouple sheaths. As pointed out previously, 

the high strength of Inconel 600 at elevated temperatures will minimize housing distortion during 

testing. The 6.4 mm (0.25 in) wall thickness is the minimum allowable for operating at 4.2 bars 

(60 psig) and 811 degrees K (1000 degrees F) taking into consideration the cutouts to 

accommodate the large windows and numerous pressure and temperature penetrations through 

the walls, as shown in Figure 2.3. The empty housing has a flow area of 83.4 cm2

 (12.9 in2). 

With the rod bundle in place the flow area is 48.6 cm2

 (7.5 in2). This area is 7.21 percent larger 

than the ideal flow area of a 7x7 rod bundle configuration. The excess flow area is due to the 

flow housing inside dimensional tolerance and the space needed to insert the rod bundle in the 

housing. The gap between the outer rods and the flow housing inner wall is 2.5 mm (0.1 in) 

wide. 

The flow housing has six pairs of windows. Each window provides a 50.8 x 292 mm (2.0 x 11.5 

in) viewing area. Each pair of windows is placed 180 degrees apart and located axially at 

elevations overlapping rod bundle spacer grids, thus providing a viewing area about 88.9 mm 

(3.5 in) below and 152 mm (6 in) above the corresponding space grids. The windows will 

facilitate the measurement of droplet size and velocity using a Laser Illuminated Digital Camera 

System (LIDCS). In addition, high speed movies using diffused back lighting can be taken 

during the experiments for visualization and flow regime information. The windows are made 

out of optical grade fused quartz and are mounted on the housing by means of a bolted flange 

and Kemprofile high temperature gasket material, as shown in Figure 2.9. 

The flow housing is supported from the nickel plate and upper plenum, allowing it to freely 

expand downward, thus minimizing thermal buckling and distortion. The two-phase void fraction 

will be measured using sensitive differential pressure cells. The flow housing has 23 pressure 

taps located at various elevations, as shown in Figure 2.3. The pressure taps are connected to 

sensitive differential pressure (DP) cells providing measurements to calculate single-phase 

friction losses for determining base rod bundle and grid loss coefficients. Sixteen of these 

pressure taps are located about 76.2 to 127 mm (3 to 5 in) apart to provide detailed void fraction 

measurements in the froth region above the quench front. 

The flow housing also has thirteen stand-off penetrations at various elevations for the traversing 

steam probe rakes which measure the superheated steam temperatures in the dispersed flow 

regime. 
11 

Figure 2.3 Test Section Isometric View. 
12 

Figure 2.4 Rod Bundle Cross Section View. 
13 

 

Figure 2.5 Heater Rod Schematic. 

NOTES: 

1.

in inchesAll dimensions 

. 
14 

Figure 2.6 Heater Rod Axial Power Profile. 

Figure 2.7 Mixing Vane Grid. 
15 

Figure 2.8 Low Melt Reservoir. 

Figure 2.9 Housing Window. 
16 

2.1.2 Lower Plenum 

The lower plenum is attached to the bottom of the flow housing. The lower plenum is made out 

of nominal 203 mm (8 in) schedule 40, 304 stainless steel pipe with an inside diameter of 202 

mm (7.94 in), a height of 203 mm (8 in), and a volume of 6570 cm3

 (0.232 ft3), as shown in 

Figure 2.10. The lower plenum is used as a reservoir for the coolant prior to injection into the 

rod bundle during reflood. It connects to the injection water line and steam cooling line. It has 

two penetrations for thermocouples monitoring the coolant temperature prior and during reflood, 

and pressure taps for static and differential pressure measurements. 

The lower plenum also has four Conax fittings with multiple probes sealing glands for the bundle 

grid, steam probes and support rod wall thermocouple extensions that are routed through the 

bottom of the rod bundle. It contains a flow baffle, which is attached to the flow housing bottom 

flange. The flow baffle has a square geometry, similar to the holes that act as a flow distributor 

and flow straightener to provide and even flow distribution into the rod bundle. 

2.1.3 Upper Plenum 

The upper plenum serves as the first stage for phase separation and liquid collection of the twophase effluent exiting the rod bundle. The liquid phase separates due to the sudden expansion 

from the bundle to the larger plenum flow area. The de-entrained liquid is collected around the 

flow housing extension in the upper plenum. The extension acts as a weir preventing the 

separated liquid from falling back into the heater rod bundle. The upper plenum vessel 

configuration is shown in Figure 2.11. The vessel is made from a 203 mm (8 in) 204 stainless 

steel pipe with an inside diameter of 202 mm (7.94 in) and a height of 305 mm (12 in). It has a 

volume of 9873 cm3

 (0.347 ft3). The plenum has a 76.2 mm (3 in) pipe flange connection to the 

steam separator and two penetrations for fluid thermocouples. It is covered with a 203 mm (8 

in) 304 stainless steel blind flange. This flange has a 25.4 mm (1 in) penetration for steam 

injection, venting, and connecting the safety relief valve and rupture disc assembly. It also has 

a pressure tap penetration for static and differential pressure measurements. In addition, the 

upper plenum contains an exhaust line baffle shown in Figure 2.12. The baffle is used to further 

de-entrain water from the steam and prevents water dripping from the upper plenum cover 

flange to be carried out by the exhaust steam. The baffle has a 76.2 mm (3 in) flange 

connection at one end. It is inserted through the upper plenum exit nozzle, and it is bolted 

between the nozzle flange and the flange of the pipe going to the steam separator. 
17 

Figure 2.10 Lower Plenum. 

Figure 2.11 Upper Plenum. 
18 

Figure 2.12 Exhaust Line Baffle. 

2.1.4 Large and Small Carryover Tanks 

The de-entrained liquid from the upper plenum drains into the top of a 25.4 mm (1 in) tube which 

extends inside a small carryover tank to detect and measure the carryover liquid as soon as 

possible. This tank, shown in Figure 2.13, is close-coupled in series with a larger carryover 

tank, shown in Figure 2.14, which collects and measures and the amount of liquid overflow from 

the smaller carryover tank. The small carryover tank has a volume of about 1388 cm3

 (0.049 

ft3

), and is used to more accurately measure the initial water being collected as a function of 

time. The smaller carry over tank is made from 50.8 mm (2 in) schedule 80 pipe having an 

overall length of 914 mm (36 in) including the end caps. The large carryover tank is made from 

a 102 mm (4 in) schedule 40 pipe with a bottom end cap and top flanges having an overall 

length of 183 cm (6 ft) and a capacity of 15917 cm3

 (0.562 ft3). Each tank is connected with 

25.4 mm (1 in) flexible hose, and has a 25.4 mm (1 in) drain tube, and 9.5 mm (0.375 in) wall 

penetrations for installing fluid instrumentation and level indicators. 
19 

Figure 2.13 Small Carryover Tank. 

1 in Inlet

1 in Outlet (To 

Large Carryover) 

1 in Drain

0.375 in TC and 

Pressure Tap 

0.375 in Pressure Tap 

2 in schedule 80 pipe 
20 

Figure 2.14 Large Carryover Tank. 

1 in Inlet 

0.375 in TC and 

Pressure Tap 

4 in schedule 40 pipe 

0.375 in Pressure Tap 

3/8 in Vent

1 in Drain
21 

2.1.5 Steam Separator and Collection Tank 

The wet steam exhausted from the upper plenum flows through a steam separator (or dryer), 

shown in Figure 2.15, where carryover liquid droplets are further separated from the steam and 

collected in a small collection tank, shown in Figure 2.16, attached to the bottom of the steam 

separator. The steam separator relies on centrifugal force action to provide 99 percent dry 

steam. The separated liquid is drained into a collection tank where a differential pressure cell is 

used as a level meter to measure liquid accumulation. The steam separator is fabricated from a 

356 mm (14 in) diameter 316 stainless steel pipe and is 914 mm (36 in) long. It has 50.8 mm (2 

in) connecting nozzles, a 25.4 mm (1 in) drain, and a 12.7 mm (0.5 in) top vent. It also has two 

pressure taps for liquid level measurements and two 38.1 mm (1.5 in) side nozzle connections. 

The drain tank is a small vessel with a capacity of 11329 cm3

 (0.4 ft3). It is made from a 102 

mm (4 in) schedule 80 pipe with an overall length of 1.78 m (70 in), including both end caps. It 

has a 25.4 mm (1 in) drain nozzle, a 25.4 mm (1 in) top pipe connection to the steam separator, 

pressure taps and fluid thermocouple connections. 

Figure 2.15 Steam Separator. 
22 

Figure 2.16 Steam Separator Collection Tank. 

2.1.6 Pressure Oscillation Damping Tank 

The dry steam from the steam separator flows into a pressure oscillation-damping tank. As its 

name implies, it is used to dampen pressure oscillations at the upper plenum caused by rapidly 

oscillating steam generation rates in the heater rod bundle during reflood. This effect is coupled 

to the characteristics of the pressure control valve, which is located downstream in the steam 

exhaust line. It is desirable to have a smooth pressure control in order to minimize uncertainties 

when calculating mass balances, steam generation rates, and heat transfer coefficients in the 

heater rod bundle, and avoid the pressure control valve causing oscillations in the bundle as it 

cycles. The tank has a volume of 0.209 m3 (7.38 ft3

), which is approximately equal to the total 

volume of the rest of the test facility. The pressure tank is fabricated from 356 mm (14 in) 

diameter, 304 stainless steel standard schedule pipe and is 2.59 m (102 in) long, as shown in 

Figure 2.17. Inside the tank is a 76.2 mm (3 in) schedule 40, 304 stainless steel pipe that 

provides a tortuous path for the steam flow to expand into a large volume, thus damping 

pressure oscillations. The inlet and outlet nozzles are 76.2 mm (3 in) in diameter with flanges. 

The vent and drain lines are made of 25.4 mm (1 in) stainless steel pipe. There are 9.53 mm 

(0.375 in) tube penetrations for a fluid thermocouple and two static pressure taps. The tank 

walls are heated with clamp-on-strip heaters up to about 11 degrees K (20 degrees F) above 

saturation temperatures to prevent steam condensation. 
23 

Figure 2.17 Pressure Oscillation Damping Tank. 
24 

2.1.7 Exhaust Piping 

The steam flows out of the pressure oscillation-damping tank through a 76.2 mm (3 in) schedule 

40, 304 stainless steel pipe shown schematically in Figure 2.18. The exhaust line has a Vortex 

flow meter, a 76.2 mm (3 in) V-Ball pressure control valve, and a muffler at the exit to minimize 

the noise caused by steam blowing into the atmosphere. The pressure control valve is 

activated by a signal from a static pressure transmitter located on the upper plenum. The line is 

also instrumented with a static pressure transmitter, fluid thermocouples, and outer wall 

thermocouples. The 76.2 mm (3 in) line has flow-straightening vanes which reduce the pipe 

length requirements upstream of the Vortex flow meter in order to obtain accurate flow 

measurements. This line has strapped-on electrical heaters to keep the wall temperatures 

about 11 degrees K (20 degrees F) above saturation to insure that single-phase steam flow 

measurements are made by the Vortex flow meter. 

Figure 2.18 Exhaust Piping. 

Vortex Flowmeter

Pressure Control 

V-Ball Valve 

Steam Vent Muffler

Drain Leg 

To Pressure Oscillation 

Damping Tank 
25 

2.1.8 Injection Water Supply Tank 

The injection water system consists of a water supply tank, a circulation pump, and 

interconnecting lines to the test section lower plenum. The water supply tank shown in 

Figure 2.19, has a capacity of 0.953 m3

 (251.75 gal). It is designed for 4.14 bars (60 psig) and 

427 degrees K (310 degrees F). The tank is equipped with a submersible electrical heater to 

heat the injection water to specified test temperatures. The tank is pressurized by a nitrogen 

supply system, which regulates the over-pressure needed for the forced flooding injection tests. 

The tank has inlet and outlet nozzles, pressure taps for level measurements, fluid and wall 

thermocouples. Water from the tank can be circulated through the test section by a centrifugal 

pump with a capacity up to 0.946 m3

/min (250 gpm), which is needed to perform liquid singlephase flow tests. 

Figure 2.19 Injection Water Supply Tank. 
26 

2.2 Facility Improvements Over Previous Tests

Significant improvements related to other heater rod bundle testing programs, listed in Section 

3.0 Literature Review of the RBHT Test Facility Test Plan and Design Report (NUREG/CR6975), have been incorporated in the RBHT Test Facility. These improvements include: 

• A low mass square flow housing design which better fits a square rod bundle array and 

minimized the housing mass and excess rod bundle flow area. 

• The six pairs of windows which provide large viewing areas below and above grid 

locations, making it possible to observe and make void fraction and droplet 

measurements during reflood testing. 

• The use of a laser illuminated Digital Camera system to measure entrained water 

droplets sizes, distribution, and velocities in the transition and disperse flow regions. 

• The use of a traversing steam probe rake to measure simultaneously steam 

temperatures in the flow subchannel and in the rod-to-rod gap. They are specially 

designed such that they would not stay wet after having contacted by liquid droplets. 

• Differential pressure transmitters axially located 76.2 to 127 mm (3 to 5 in) apart in 

conjunction with heater rod and flow housing wall thermocouples to obtain detailed void 

fraction and heat transfer information. 

• Water droplet injection system in conjunction with steam injection to study the dropletsteam cooling effects on heat transfer and grids. 

• Addition of a large pressure oscillation-damping tank to minimize test section oscillations 

observed in the FLECHT and FLECHT-SEASET tests. 

• The incorporation of close coupled entrained liquid collection tanks and piping to reduce 

delay times for liquid collection. 

2.3 Instrumentation and Data Acquisition System

The test instrumentation is designed to measure temperatures, power, flows, liquid levels, 

pressures, void fractions, droplet sizes, distributions, and droplet velocities. The vapor velocity 

cannot be directly measured in a two-phase dispersed flow, but it can be calculated at different 

axial positions from the data. Overall the transient mass and energy balances, mass 

inventories, carryover liquid and steam flow can be calculated as functions of time. Heater rod 

power, heat rod temperature, and fluid temperature are used to calculate heat fluxes and heat 

transfer coefficients, quench times, rod bundle energy losses, convective and radiation heat

transfer to steam, droplets, grids, support rods, and housing. Effects of grids, support rods and

housing behavior during reflood can be determined. Void fraction measurements below the 

quench front and in the froth level above the quench front, in conjunction with the laser 

illuminated digital camera measurements are used to determine droplet entrainment behavior, 

droplet effects on heat transfer, and steam desuperheating. The laser illuminated digital camera 

system measurements provide droplet size distribution and velocities during reflood. 
27 

2.3.1 Loop Instrumentation and Controls 

Loop instrumentation is shown schematically in Figure 2.20. There are 123 instrumentation 

channels assigned to the collection of electrical power, fluid and wall temperatures, levels, flow 

differential pressures, and static pressure measurements. The injection water supply tank has 

three fluid and three wall thermocouples to monitor water and wall temperatures during heat-up 

prior to testing. It has a differential pressure transmitter used as a level meter to determine 

water mass in the tank and mass depletion during reflood testing. It also has a static pressure 

transmitter that monitors the nitrogen over pressure and controls the nitrogen flow needed to 

maintain a constant pressure during forced injection reflood tests. The water injection line is 

equipped with a Coriolis Effect Micromotion flow meter that directly measures mass flows up to 

454 kg/min (1000 lbs/min) with an accuracy of plus or minus eleven hundredths of a percent 

(±0.11percent) of rate. The steam line has a Rosemount Vortex shedding flow meter to 

measure flow up to 7.08 m3

/min (250 ft3/min) with an accuracy of plus or minus 65 hundredths 

of a percent (±0.65 percent) of rate. Each flow meter is connected through a pneumatic 

controller to a V-ball flow control valve. Each line has a fluid thermocouple to measure water or 

steam temperature during heat-up and forced injection testing. They also have a static pressure 

transmitter which in conjunction with the thermocouples can determine the thermodynamic 

properties of the fluid. The injection line has three wall thermocouples to monitor wall 

temperatures during heat-up and during testing. One of these thermocouples in conjunction 

with a temperature controller regulates the power to an electrical heating cable wrapped around 

the injection line. The heating cable is used to heat-up the injection line wall and to maintain the 

injection water at the required injection temperature. 

The small carryover tank has one fluid and two wall thermocouples. The large carryover tank 

instrumentation consists of one fluid thermocouple, three wall thermocouples. Both tanks have 

a liquid level meter, which measures the amount of carryover liquid being collected during 

testing. In addition, a differential pressure transmitter is connected from the top of the carryover 

tank to the upper plenum to determine the static pressure in the carryover tank. 

The steam separator is instrumented with one fluid and two wall thermocouples. The drain tank 

is instrumented with two fluid and two wall thermocouples. The fluid thermocouple measures 

the de-entrained water temperature during testing. The wall thermocouples monitor wall 

temperatures during heat-up. The volume of de-entrained water is measured with a level meter 

connected across the drain tank. 

The pressure oscillation damping tank has two fluid and three wall thermocouples which are 

used to monitor vessel walls during heat-up, and to insure that the vessel wall is at a 

temperature above saturation to prevent condensation. One wall thermocouple in conjunction 

with a temperature controller monitors the power applied to clamp-on heaters that heat up the 

tank to the desired wall temperature. 
28 

Figure 2.20 Loop Instrumentation Schematic. 
29 

The exhaust line is equipped with a Vortex flow meter which, in conjunction with a static 

pressure transmitter and fluid thermocouple measurements, is used to calculate steam 

volumetric flows up to 7.08 m3

/min (250 ft3/min). The flow meter has an accuracy of plus or 

minus 65 hundredths of a percent (±0.65 percent) of the rate. The exhaust line also has three 

wall thermocouples to measure pipe wall temperatures. One wall thermcouple in conjunction 

with a temperature control regulates the power going to clamp-on-heaters which are used for 

heating the pipe walls up to a temperature of about 11 degrees K (20 degrees F) above 

saturation to prevent steam condensation and to insure accurate single phase steam flow 

measurements. The exhaust line has a V-ball pressure control valve. This valve is controlled 

by a static pressure transmitter through a pneumatic controller connected to the top of the upper 

plenum in order to maintain constant test section pressure during testing. 

2.3.2 Test Section Instrumentation 

The test section instrumentation consists of the heater rod bundle and flow housing, the low 

plenum, and the upper plenum groups. The heater rod bundle and flow housing instrumentation 

is shown schematically in Figure 2.21. This figure shows the instrumentation axial locations in 

relation to heater rod heated length, grids, steam probe rakes, housing pressure taps and 

windows. 

Six grids have thermocouples attached to their surfaces in order to determine quenching 

behavior during reflood shown in Figure 2.23 through Figure 2.29. Grid and steam probe axial 

locations are shown schematically in Figure 2.21. Eight groups of heater rods have 

thermocouples at different elevations to cover, as much as possible, the entire rod bundle 

heated length. The radial location of each heater rod group is shown in Figure 2.22. The radial 

locations of instrumentation rods were chosen in order to be able to characterize heat transfer of 

hot rods simulated by the center rods, rod-to-rod and rod-to-housing radiation heat transfer. For 

this purpose, heater rod thermocouples, steam probes, and housing wall thermocouples are 

located at the same elevations. In addition, symmetrical location of the same group of 

instrumented heater rods will help in the data analysis and will determine any anomalies in the 

radial flow distribution through the heater rod bundle. Heater rod thermocouples are also placed 

at varying distances downstream from a grid to determine the decreasing heat transfer gradient 

between grid spans. The steam probes or fluid thermocouples are located at short distances 

upstream and downstream of a grid to determine the effect of water droplets being shattered by 

the grids on droplet size and distribution, and the desuperheating effect on the steam 

temperatures in the disperses flow regime. 
30 

Figure 2.21 Rod Bundle and Housing Instrumentation Axial Locations. 
31 

Figure 2.22 Instrumented Heater Rod Radial Locations. 

Figure 2.23 Mixing Vane Grid Instrumentation. 

7 0 7 0 0 

0 1 2 6 1 8 0 

0 8 5 3 8 4 0 

7 3 3 3 5 3 0 

0 2 4 8 2 4 0 

7 1 2 6 1 8 0 

0 6 7 7 0 
32 

Figure 2.24 Grid No. 2 Instrumentation. 

Figure 2.25 Grid No. 3 Instrumentation. 
33 

Figure 2.26 Grid No. 4 Instrumentation. 

Figure 2.27 Grid No. 5 Instrumentation. 
34 

Figure 2.28 Grid No. 6 Instrumentation. 

Figure 2.29 Grid No. 7 Instrumentation. 
35 

The vapor or steam temperature will be measured using miniature thermocouples having a 

diameter of 0.813 mm (0.032 in) which are attached to the spacer grids, as well as the 

traversing steam probe rakes having a diameter of 0.381 mm (0.015 in). These are very small 

diameter thermocouples that have a fast response time such that they can follow the vapor 

temperature accurately in a dispersed, non-equilibrium, two-phase flow. As the froth front 

approaches, the number and sizes of the droplets increase which can lead to wetting of these 

thermocouples. Experiments performed as part of the FLECHT-SEASET program indicated 

that very small thermocouples would provide reliable vapor superheat ready for the longest time 

period until they quench as the froth region approaches. While the Lehigh vapor probe was 

considered, it is too large and causes a flow distribution effect which is not typical of the bundle. 

The Lehigh probe would block 68 percent of the gap between adjacent heat rods. The effect of 

the probe would be to distort the data downstream of the sensing location. Such flow 

distribution effects were observed in the Lehigh data as well as the INEEL single tube data 

which used these probes. 

The traversing steam probe rakes are located at the spans between the grids at the upper 

heater rod bundle elevations, as shown schematically in Figure 2.30. The traversing steam 

probes rakes will measure steam temperatures in the heater rod bundle flow subchannels and 

the gaps between the heater rods during the dispersed flow regime. Each rake consists of three 

0.381 mm (0.015 in) diameter ungrounded thermocouples mounted on a 0.356 mm (0.014 in) 

thick by 6.35 mm (0.25 in) wide Inconel strip. The thermocouples are spaced 12.6 mm (0.496 

in) apart which correspond to the heater rod spacing in the bundle. The thermocouple tips are 

located facing the steam flow. A 2.39 mm (0.094 in) diameter tube attached to the strip is used 

to traverse the steam probe rake across the rod bundle. This tube also carries the 

thermocouples leads outside the flow housing through a pressure seal. The tube is attached to 

an automated sliding mechanism. It consists of a sliding bar, a 24 DCV motor with a ball drive 

shaft, and a linear potentiometer provides a voltage input to the Data Acquisition which 

determines the rake thermocouple location and travel distances across the heater rod bundle. 

 

Two fluid thermocouples are placed 24.5 mm (1 in) below the bottom of the bundle heated 

length such that injection water temperatures are monitored prior to and when reflood is started. 

There are 23 differential pressure transmitters connected to the housing wall pressure taps 

providing measurements to calculate single phase flow bundle and grid friction losses, bundle 

mass inventory, and void fraction during reflood. There are nine differential pressure cells 

connected to pressure taps located 76.2 mm to 127 mm (3 to 5 in) apart to provide detailed 

mass inventory, and void fraction data in the froth region above the quench front. In addition, 

heater rod and housing wall thermocouples are placed at these pressure tap mid span locations 

to determine convective and radiant heat transfer coefficients in the froth region where the 

differential pressure cells will give the average void fraction. 

The flow housing has six pairs of windows at the following elevations: 61.4 cm (37.2 in), 114 cm 

(44.7 in), 166 cm (65.3 in), 218 cm (85.8 in), 270 cm (106.4 in), and 322 cm (126.9 in). Each 

pair of windows are 180 degrees apart. The window lenses are made from optical grade fused 

quartz and provide a viewing area of about 10.2 cm (4 in) below and 15.2 cm (6 in) above grids 

two through seven. The windows are preheated to minimize wetting during reflood using 

infrared heaters on each window and by pulsing the heater rod bundle when preheating the flow 

housing walls. The infrared heaters are removed just before a test is started. Droplet 

measurements above and below a grid can be made through the windows. 
36 

Figure 2.30 Traversing Steam Probe Rake Schematic. 

A droplet imaging system known as VisiSizer was developed in conjunction with Oxford Lasers 

to measure the size and velocity of water droplets entrained in the steam flow of the RBHT test 

section shown schematically in Figure 2.31. VisiSizer uses a pulsed infrared laser to image 

water droplets on a 1000x1000 pixel high-resolution black and white digital camera through a 

set of windows in the bundle housing. A digital system such as VisiSizer was chosen over 

conventional high-speed cameras which are capable of only a few seconds of imaging and have 

lower data acquisition speeds. Further, each frame from a standard imaging technique would 

need to be analyzed by hand. The VisiSizer system is capable of analyzing 12 to 13 frames per 

second for an indefinite period of time. Film from the FLECHT-SEASET tests show poorer 

image quality than images taken with VisiSizer in the RBHT experiments. However, VisiSizer is 

incapable of measuring anything other than complete droplets. This makes it an inadequate 

tool for gathering information about the entrainment front where there are ligaments and other 

unusual water behavior. 
37 

Figure 2.31 Laser Illuminated Digital Camera System Setup. 

An infrared laser is used with the system because it is capable of passing through the quartz 

viewing windows and being absorbed by the water droplets entrained in the steam flow. 

Because the infrared rays are absorbed by the water droplets, the resulting droplet shadows 

can be recorded by the digital camera. So far, there has been no effect of laser light scattering 

from rods to droplets. Pictures taken in and out of the rod bundle have the same imaging 

characteristics, droplet analyzing capability and clarity. A band pass laser light filter is placed in 

front of the digital camera to eliminate non-infrared light from other sources and an anti-glare 

attachment is used to eliminate any illumination interference from outside the viewing area. In 

addition, rod bundle geometry has little effect in the measurement of droplet distributions and 

velocities. 

The frames captured by the camera are fed back to a PC at approximately 12 to 13 frames per 

second. The software can analyze each frame for droplet size and velocity and write the 

recorded data to a size and velocity data array. The software program determines droplet sizes 

by determining the area of black vs. white pixels in each droplet image. Once the droplet area 

is determined, the program calculates the perimeter of the droplet image to determine the 

sphericity of the droplet. The VisiSizer system is capable of determining the surface area based 

on diameter of any and all droplets. 

Operating the laser in a double pulse mode enables the VisiSizer system to measure both 

droplet diameter and velocity for a particular probe volume. The laser pulses twice with a 

known pulse delay (on the order of 1 ms) while the camera shutter remains open, creating two 

images in the same frame for each droplet. The distance between images is then determined 

and the velocity calculated. These velocity characteristics are enough to characterize the 

behavior of the flow despite the fact that the droplets are only captured in a single frame. 

The local distribution of droplets can be determined for a known probe volume governed by the 

software settings. Droplets that lie out of this probe volume on either side of the line of sight will 
38 

be rejected based on focus. The opposite sides of the probe volume will be set by the spacing 

of the rods in the bundle. Each droplet is recorded in a two-dimensional array according to size 

and velocity. The droplet sizes are recorded in lognormal bins while the velocity bin size is user 

defined. Data for the transient reflood experiments is recorded in user defined quasi-steady 

state time periods. At the end of each time period the data is saved and a new array is opened. 

The VisiSizer enable the experimenters to collect a vast amount of information about the droplet 

flow in the test section. The information will be collected in an easy to handle data array and all 

information will be written to a CD-ROM to ensure the information will be available for later use. 

The four corner support rods are unheated, they are used to support the bundle grids and to 

support grid and steam probes thermocouple leads going out of the bundle. These rods are 

instrumented with eight thermocouples attached at various elevations corresponding to heater 

rods and housing wall thermocouples. The purpose of this arrangement is to quantify radiation 

heat transfer losses to unheated surfaces and determine their behavior during reflood. 

The DC power supply can be controlled by regulating the voltage, current, or total power output. 

The voltage drop across the heater rod bundle is measured by a voltmeter connected to voltage 

taps at the Low-Melt pot and the Nickel Ground Plate. The electrical current is measured by a 

copper shunt calibrated for 15,000 amps proportional to an output signal of 0-50 millivolts. 

The lower plenum is instrumented with two fluid and two wall thermocouples. The fluid 

thermocouples monitor the injection water temperature prior and during testing. The wall 

thermocouples measure the vessel wall during heat-up and testing. One of the wall 

thermocouples in conjunction with a temperature controller regulates electrical power to clampon-heater rods to maintain the vessel wall at inlet temperatures. 

The upper plenum is also instrumented with two fluid thermocouples and two wall 

thermocouples. The fluid thermocouples measure steam and carryover liquid during testing. 

The wall thermocouples monitor vessel wall temperatures during heat-up and testing. The 

Upper Plenum is also instrumented with a static pressure transmitter which measures and 

controls the test section pressure during testing. 

2.3.3 Data Acquisition System 

The control and data acquisition system provides control functions and data collection functions 

for the RBHT Test Facility. This system consists of two parts: the computer and deplay 

terminals residing in the control room and the VXI mainframe and terminal panels residing in the 

test facility. The two parts are connected via an industry standing IEEE 1394 (Firewire) serial 

control and data interface. 

The computer provides the display, control, and data storage functions. It has the capability of 

displaying control function set points and process variables, and critical operating parameters 

during tests, along with selected variables such as various rod temperatures displayed in realtimes during the experiment. This system will provide dial, meter, and strip-chart functions as 

required. The computer collects and saves data from the various instruments, such as voltage, 

current, pressure, level flow and temperature; and provides control functions such as heater rod 

power, injection water pressure, upper and low plenum temperatures, etc. 
39 

The instrumentation part of this system, residing in the test facility, consists of an industry 

standard VXI mainframe (Vme bus with extensions for Instrumentation) from Hewlett-Packard 

(HP-E8401AA), and a set of terminal panels (HP E1586A). The VXI mainframe contains a 

firewire controller card (HPE8491A) and several (currently seven) state-of-the art data 

acquisition and control cards (HP E1419A). The terminal panels provide the isothermal 

reference junctions needed for the thermocouples, as well as the voltage and current-loop 

input/output (i/o) interface to the RBHT Test Facility. These terminal panels are connected to 

the HP E1419A cards with SCSI cables. Seven cards yield a capability of 448 I/O. The VXI 

mainframe can hold up to twelve cards, and the firewire interface can support up to sixteen 

mainframes. 

Each E1419A card can support up to eight signal conditioning plug-ons (scp’s), conditioning 

eight channels each. Each E1509A scp contains low-pass anti-aliasing filters, fixed at 7 Hz. 

Because of this, the scan rate for each channel must be greater than or equal to the Nyquist 

rate of 14 Hz. The maximum a/d conversion rate on each HP E1419A card is nominally 

100kHz, but is controlled to rate the user requires. The seven cards can be synchronized to 

perform the scans simultaneously. The theoretical maximum scan rate for each channel (on 

any individual card) is 100,000/64 = 1,56235 Hz, if all 64 channels are scanned. (Note, the 

actual scan rate would be less because of multiplexer switching, amplifier settling times due to 

gain changes, etc. There are different scp’s available from HP providing different filter values to 

scan at these rates.) The normal data-scanning rate will be 2 Hz during the majority of the 

tests, but this rate can be increased to 10 Hz for specific times during testing. 
40 

3. CALCULATIONAL METHODS USED FOR THE RBHT REFLOOD 

HEAT TRANSFER EXPERIMENTS 

3.1 Transient Heat Transfer Coefficient Calculation (DATARH)

3.1.1 Introduction 

The DATARH program is used to calculate the transient heater rod outside surface temperature, 

the total surface heat flux and a FLECHT type heat transfer coefficient defined as 

( )

"

W sat

w

FLECHT T T

q h − = (3-1)

which is referenced to the saturation temperature in the test bundle. Both the surface heat flux 

" qw and the FLECHT heat transfer coefficient represent a total heat transfer from the heater rod 

surface and would include radiation heat transfer as well as convection and flow boiling. 

Program DATARH.F contains the source code to perform an inverse heat conduction 

calculation in an electrically heated rod, in which internal cladding thermocouples exist. 

The purpose of the code is to calculate the surface temperature, the surface heat flux and the 

FLECHT type transient heat transfer coefficient for heater rods. The program uses 

experimental data and heater rod dimensions to perform calculations. The mathematical model 

for the calculations is described in Section 3.1.2 below. 

The program described herein has been modified for the RBHT experiments from the 

DATARH.F program used for the FLECHT-SEASET experiments. Differences between heater 

rods used in the FLECHT-SEASET experiments and the RBHT experiments (e.g., rod 

dimensions, differences in rod internal materials) have been accounted for in this version of the 

program. 

The sections that follow describe the structure of the DATARH program, RBHT rod geometry, 

heater rod materials, and the input files required for executing the current version of the 

program. 

3.1.2 Mathematical Model 

A heat conduction problem is termed an “Inverse Heat Conduction Problem” if at least one 

spatial condition is specified at an interior point of a heat conducting body. Because of this unorthodox condition, the solution to an inverse problem is more complicated. Even if the 

governing equations are linear, classical methods such as Fourier analysis and Laplace 

transformation would fail to yield a solution. For the Fourier method, the eigenvalues are not 

readily obtainable from the resulting Strum-Louivalle system of equations; hence, Fourier series

representation of the solution cannot be determined. Transformation techniques lead to a 

solution in Laplace variable space which defines an inverse transform into the real time space. 

Although the numerical method is not without difficulty, meaningful results can be obtained if 

due care is exercised. 
41 

The finite difference approximation in implicit form of a one-dimensional heat conduction equation in 

cylindrical coordinates is typically 

B(n)T(n −1) + A(n)T(n) + C(n)T(n +1) = T'(n) − Q(n);1 ≤ n ≤ N (3-2)

where 

( ) ( )

( 1/ 2)

( )

( 1/ 2)

( ) ( ) 2 n c n

k n

r n

r n B n

θ ρ

θ − ⋅ −

Δ

Δ = (3-3) 

( ) ( )

( 1/ 2)

( )

( 1/ 2)

( ) ( ) 2 n c n

k n

r n

r n C n

θ ρ

θ + ⋅ +

Δ

Δ = (3-4)

A(n) = B(n) − C(n) −1 (3-5) 

( ) ( )

( ) ( )

n c n

q n Q n

ρ

Δθ = (3-6)

and T(n) the unknown temperature node at point n, T'(n) the known temperature at node point n 

(This is also the “initial value”), r the spatial variable, Δr the spatial increment, and Δθ the time 

increment. 

k, ρ, c are the thermal conductivity, density and heat capacity, respectively. Their numerical 

values are computed at T'. If values at half intervals are required, they are evaluated at the 

average of two adjacent temperatures. q is the volumetric heat generation rate. N is the 

number of internals. Hence, there are N+1 node points. 

For n = 1, the node point is at the center of the rod, T(n-1) = T(n+1), since at this point the 

symmetry requires the flux be zero. At the point n-M, T(n) is the known measured temperature 

and finally, at the outer boundary point, n = N, T(n+l) is the desired wall temperature. If the heat 

conducting body is made up by composite material, the temperature at the interface can be 

handled by usual means; i.e., both the temperature and flux must be continuous. However, in 

this case, the spatial interval size, Δr, would vary from region to region such that particular node 

points coincide with the material interfaces and T(M). 

Apply Equation (3-2) to node points n = 1,2,...N and combining the boundary condition T(0) = 

T(2) with the finite difference equation at n = 1 to eliminate T(0), we have a set of N linear 

simultaneous equation with N unknown temperatures, T(n); n = 1,..., N+1, n ≠ M. The solution 

of this set of equations defines the temperature field at a given time step, θ. The transient 

solution can thus be obtained by repeating the same procedure with successive increments of 

Δθ. 

The method outlined above is simple-minded in principle and straightforward in practice. 

Because of the implicit finite difference scheme, the stability of the computation is guaranteed. 

As long as reasonable increment sizes, Δr and Δθ, are chosen, acceptable numerical accuracy 

is expected. 
42 

It is noticed that if M = N+1, the inverse heat conduction problem is reduced to a more 

conventional type with a flux condition specified on one boundary (centerline) and a temperature 

condition specified on the other (wall). In this case, the coefficient matrix for the linear 

equations, as defined by Equation (3-2), is tri-diagonal. However, the presence of a known 

temperature, T(M) at M ≠ N+1, in the linear set to replace the wall temperature, T(N+1), 

destroys the tri-diagonality and consequently complicates the solution procedure since for linear 

equations with a tri-diagonal coefficient matrix, the solution can be obtained by a time saving 

matrix resolution technique which is not applicable to any other form of matrix. 

Let us, for the time being, ignore the fact that T(M) is known and assume that T(N+1) is known 

instead. The linear equation, written in the usual manner is: 

J T F C N T N G    [ ] = − ( ) ( +1) (3-7)

where [J] is the tri-diagonal coefficient matrix defined by Equations (3-2) and (3-3), T



the 

solution vector with N components, F



 the “source” vector with the components defined by the 

quantities on the left-hand side of Equation (3-2), G



 the vector with first N-1 components equal 

to zero and the N-th component equal to one (i.e., q(i)=C, i≠N, q(i)=l, i=N). 

If X



 and Y



 are, respectively, solutions of 

J X F   [ ] = (3-8) 

J Y G   [ ] = − (3-9) 

The linearity of Equation (3-7) leads to 

T X C N T N Y    = + ( ) ( +1) (3-10) 

Equation (3-10), in scalar form for n = M, gives 

T(M ) = X (M ) + C(N)T(N +1)Y(M ) (3-11) 

or 

, Y(M) 0

( ) ( )

( ) ( ) ( 1) ≠ − + = C N Y MT M X M T N (3-12) 

Since all the quantities on the right hand side of Equation (3-11) are known, the wall 

temperature T(N+1), can be computed. The remaining temperature field can be obtained by 

repeated application of Equation (3-10). 

If the transient temperature measurement T(M) is both accurate and frequent enough, the 

method outlined above will produce acceptable results. In practice, however, such accuracy 

and frequency as demanded by the numerical method is almost impossible to achieve. Any 
43 

error in T(M), either due to instruments or due to interpretation, would be amplified in this 

numerical process. An error is usually propagative and oscillatory and results from a 

successive over and under correction of the heat balance as demanded by the governing heat 

conduction equation. A small error in T(M) often renders the calculations for wall temperature 

and wall flux useless since their error is amplified as the calculation steps through time. 

Therefore, it is desirable to devise a numerical method such that the input error of T(M) could be 

damped during the subsequent computation steps. One such method is programmed in 

DATARH. It must be stressed that damping of input error can only improve the accuracy of the 

computed results by reducing the input error amplification. The inheritant error due to 

inaccurate input data still remains. 

The basic principle of the method is to utilize the information of T(M) available over an open 

time span when the computation is just entering this time span. Let the parenthesized 

superscript denote a relative time step, then the computation of (1) T

 would not only involve an 

initial value (0) T

 , but also ( ), ( ),... (2) (23) T M T M   This calculation is followed by an optimization 

process to minimize the error amplification. This optimization can be accomplished in, although 

not restricted to, a least-squared sense. 

Following Equation (3-2) and the subscript notation defined above, we have: 

 ) ( ) ( 1) ( ) ( ) ( ) ( 1) ( ) ( (1) (1) (1) (0) B n T n − + A n T n + C n T n + = −Q n −T n (3-13) 

 ) ( ) ( 1) ( ) ( ) ( ) ( ) ( ) ( 1 (1) (1) (0) B N T N − + A N T N = −Q N − T N −C N T N + (3-14) 

The solution using Equation (3-10) is; 

(1) (1) (1) T X C(N)T(N 1)Y    = + + (3-15)

In the above equation, all of the components in (1) X

 and (1) Y are known. (1) T is not known 

since the wall temperature T(N+1) needs to be determined. 

The computation can be carried out for one more time step as: 

(1) (1)

(2)

(2) (2) (2)

( ) ( ) ( ) ( 1)

( ) ( )

( ) ( 1) ( ) ( ) ( ) ( 1)

Q n X n C N T N Y

Q n T n

B n T n A n T n C n T n

  = − − − +

= − −

− + + +

 (3-16)

( ) ( ) ( ) ( 1){ } ( ) 1

( ) ( ) ( ) ( 1) ( ) ( ) ( 1)

( ) ( ) ( ) ( 1)

( ) ( 1) ( ) ( )

(1) (1)

(1) (1)

(1)

(2) (2)

= − − − + +

= − − − + − +

= − − − +

− +

Q N X N C N T N Y N

Q N X N C N T N Y N C N T N

Q N T N C N T N

B N T N A N T N

 (3-17) 
44 

The above equations form a linear system which is in the same form as that defined in Equation 

(3-7) provided that the vectors F



and G



are suitably modified. The linear set has the solution of 

the form of Equation (3-10) 

(2) (2) (2) T X C(N)T(N 1)Y    = + + (3-18)

For the other time steps, similar equations can be written: 

(3) (3) (3) T X C(N)T(N 1)Y    = + + (3-19)

 J ( ) ( 1) ; j 1,2,...., ( ) ( ) ( ) = + + = j j j T X C N T N Y    (3-20)

In the above equations, the vectors ( j) X

 and ( j) Y are known for all j and time steps. The 

computation can terminate at any value of J. This set of equations are optimized to obtain the 

value of T(N+1). 

At a location where the measurements are recorded for T(j)(M), Equations (3-19) and (3-20) 

give 

 ) ( ) ( ) ( ) ( 1) ( ( ) ( ) ( ) T M X M C N T N Y M j j j = + + (3-21) 

The measured temperatures u(j) are known for all values of j. The error between the computed 

and measured temperature is given as 

X M C N T N Y M u j J

j T M u

j j j

j j

( ) ( ) ( 1) ( ) ; 1,2,....,

( ) ( )

( ) ( ) ( )

( ) ( )

= + + − =

θ = − (3-22) 

The problem is now reduced to finding a T(N+1) such that θ is at a minimum. This can be 

accomplished by a least-squares method 

{ }{ }(2) ( ) ( ) ( ) 2 2 ( ) ( ) ( ) ( 1) ( ) j j j j θ =  j E = jX M + C N T N + Y M − u (3-23) 

dT(N +1) => 0 (3-24) 

( ) ( 1) 0

( )

( )

( )

( ) ( )

+ + = −  C N T N

Y M

X M u j j

j j

 (3-25)

( )

( )

( )

1 ( 1) ( )

( ) ( )

Y M

u X M j C N

T N j

j j − + =  (3-26)

Therefore, the desired temperature field can be calculated by 
45 

(1) (1) T X C(N)T(N 1)Y    = + + (3-27)

Equation (3-27) defines the initial values for the computations of the subsequent time step. The 

computation can be carried out repeatedly for each advance of time increment. 

3.1.3 Structure of the source program DATARH.F 

This section briefly describes the structure of the source program. Detailed comments may be 

found within the body of the source program as well. The reader is advised that it will be helpful 

if a listing of the program DATARH.F is referenced as the remainder of this section is being 

read, since this will enhance the reader’s understanding of the description of the program 

structure that follows. 

All real variables used in the program have been declared double precision numbers, as 

indicated by the use of the implicit double precision (a-h, o-z) statement. The program reads 

two character variables, title1 and rloc, that may each be up to 15 alphanumeric characters in 

length. These are intended to be identifiers of a test case. No intermediate spaces may be 

present within each set of alphanumeric characters. However, each identifier may be of length 

less than 15 alphanumeric characters if desired. 

The program utilizes a number of data arrays, which may be identified by examining the 

dimension statements within the main program and sub-programs. It is important to note that 

some of these arrays have been declared to be of length 20000, while others have been 

declared to be of length 10 or 50. There are several arrays that have multiple dimensions; e.g., 

array ti is seen to be of dimension 10x10. These numerical figures are indicative of limits built 

into the program. 

The length 20000 indicates that the current version of the program is capable of reading in up to 

a maximum of 20000 sets of input data, each comprising time, clad temperature and power to 

the rod being analyzed (See input file described below). It also indicates that the maximum 

number of points in time for which the program is capable of computing heat flux and heat 

transfer coefficient values is limited to 20000. 

The length 10 indicates that the region between two adjacent conduction nodes may be divided 

into a maximum of 10 sub-regions. As seen by the data (r(i), i = 1,5) statement, the program is 

capable of handling five outer conduction nodes and one implied conduction node at the rodcenter, and hence five regions. Thus, the length 50 arises from the fact that the total number of 

sub-regions that may be handled by this version of the program is 10x5. The radial distance 

from the center of a heater rod to each outer conduction node is initialized by the data (r(i), i = 

1,5) statement. 

The program reads input data via an input file. The file name is “datarhin.dat” and the file must 

exist at the time the executable is run. The required content of this file is described in a section 

that follows. The program will write output data to a file by the name of out1.dat. This file will be 

created by the executable during a run, and a file by this name must not be present in the 

working directory at run-time. If the output file from a previous run exists, it must either be 

deleted, or be renamed. 
46 

Initializing the number of sub-regions within the region between a given pair of conduction 

nodes is accomplished by the array intv(i), i = 1 through 5. As discussed above, the maximum 

number of sub-regions within any region is limited to 10. The heater rod length is set to be 3.66 

m (12 ft) by means of variable tlength. 

After all input data has been read, and once the initialization of the conduction region 

dimensions and heater rod length has been completed, the program will write a summary of the 

input data to the output file. It is after this that the computational procedures begin. 

The first step is to convert the input time scale (array timer) so that the time of reflood is treated 

as zero-time. This is accomplished by a do loop that causes the time of reflood, tflood, to be 

subtracted from each time value (array timer) that was read by the program. Next, the number 

of data points that would be output by the program, jtime, is computed using the last value of 

input time, timer(nscan), the first value of input time, timer(1), and the value of dt (which is the 

time interval between results computed by the program). Note that nscan is the number of sets 

of input data points. Now, an array of time values at which results will be output, array time, is 

computed. This too is accomplished by a do loop, and is performed by first setting time(1) equal 

to timer(1), and then successively adding the value of dt to the current value of time to get the 

next time value. 

The next step is to compute an array of sink temperatures, Tsink. This array will have nscan 

number of values. It should be noted that the current version of the program treats the 

saturation temperature corresponding to the operating pressure as the sink temperature 

throughout the length of the heater rod. Thus, all values in array Tsink will numerically be the 

same. 

The program will now access an interpolation subroutine (subroutine tbl) to compute the 

saturation temperature, rod power, and the clad temperature at each value in array time (the 

time values at which results are desired). The value of sink temperature computed, Tsink, will 

be written to the output file at this time as well. 

Preparation of an array, q, that will contain volumetric heat generation rates at each value of 

array time is performed next. Each interpolated value of rod power (at a given value of time) is 

multiplied by the axial power factor, fax, and the radial power factor (if applicable), fp, and is 

divided by the total rod length. Then, each resulting value of q is converted to a volumetric heat 

generation rate by means of appropriate conversion factors and rod dimensions. 

It should be noted that the values for fax, fp, and fka have been calculated for each 

thermocouple location in the RBHT rod bundle and are hardwired into the DATARH source 

code. Although placeholders still exist in the required input file they are not used during 

calculations and it is recommended that the values of these variables be set to zero in the input 

file. 

The program investigates the curvature of the future three data points next. The subroutine that 

performs the inverse conduction calculation is called after this computation. Once the inverse 

conduction calculation is completed for all time values desired, values of heat flux and heat 

transfer coefficient at the rod surface are computed. These values along with the computed rod 

surface temperature at each time value are then written to the output file. The program will then 

continue onto the next case (if input data are present), or will terminate if the end of input data 

has been reached. 
47 

3.1.4 RBHT Rod Geometry and Materials 

Figure 2.4 shows the cross section of the RBHT bundle. The bundle has forty-five heater rods 

and four unheated corner rods. The corner rods are used to support the bundle and provide 

exits for the grid thermocouple leads. The support rods are made from Inconel 600 tubing 

having a diameter of 9.525 mm (0.375 in), a wall thickness of 2.108 mm (0.083 in) and a form 

length of 3.96 m (156 in). Figure 2.5 shows the cross section of an electrically heated rod. The 

heater rods are single ended and consist of a Monel 500 electrical resistance element filled and 

surrounded by hot pressed Boron Nitride (BN) insulation and enclosed in an Inconel 600 

cladding as shown in the figure. The heater rods are 3.66 m (12 ft) in heated length with a 

skewed axial power profile, as shown in Figure 2.6, with the peak power located at 2.74 m (9 ft) 

elevation. The bundle has a uniform radial power distribution. The maximum to average power 

ration (Pmax/Pavg) is 1.5, and the minimum to average power ratio (Pmin/Pavg) is 0.5 at both ends 

of the heated length. 

Table 3.1 shows the description of the geometry for the RBHT heater rod geometry and 

dimensions. 

 Table 3.1 Geometry and Dimensions of RBHT Heater Rod 

Material r (mm, in) Thickness of each region dr (mm, in)

Boron Nitride 0,0 1.71, 0.07 

Monel K-500 1.71, 0.07 1.14, 0.045 

Boron Nitride 2.86, 0.113 1.18, 0.047 

Inconel 600 4.04, 0.159 0.71, 0.028 

Rod Radius 4.75, 0.187 
48 

3.1.5 Input File Required for Executing the Current Version of the Program 

The program reads input data via an input file names datarhin.dat. This file must exist at the 

time the executable is run. 

The input file, datarhin.dat should contain sets of input data arranged in lines, one line being 

required per reflood experiment analyzed. Each line must have values for the following input 

variables in the specified format, separated by one or more spaces: 

IFAC: Integer. Test facility identifier, 4 for RBHT facility. 

ITEST: Integer. Identifier for experimental run. 

ICHAN: Integer. Identifier for thermocouple channel. 

IMETRIC: Integer. Units of input data, 0 for British, 1 for SI. 

NSCAN: Integer. Number of input data points. 

DT: Real. Desired time interval between successive values of heat 

 flux and heat transfer coefficient calculated [s]. 

TFLOOD: Real. Time of reflood start [s]. 

TSTOP: Real. Time of refloof stop [s]. 

TITLE: Character, A15. Identifier for each experimental run. 

RLOC: Character, A15. Rod location/elevation. 

FAX: Real. Axial power factor (hardwired in source code but value of 

 0.0 must be present in input file). 

FP: Real. Fraction of zone power to this rod (hardwired in source 

code but value of 0.0 must be present in input file). 

FKA: Real. Volumetric fraction of Monel 500 (hardwired in source code 

but value of 0.0 must be present in input file). 

PRES: Real. System pressure [psia]. 

 

NSCAN sets of time, bundle power, and clad temperature follow. One set of values must 

appear on each successive line and each value must be separated by at least one space. A 

description of the data required follows: 

TIME: Real. Array of experimental time values [s]. 

POWER: Real. Bundle Power at corresponding TIME value [kW]. 

TEMP: Real. Experimental temperature at corresponding TIME value for 

 ICHAN [degrees F or K] (depending on IMETRIC value). 

The sample input and output files from DATARH are given at the end of this section. 
49 

Sample input file: datarhin.dat 

IFAC ITEST ICHAN IMETRIC NSCAN DT TFLOOD TSTOP 

 4 937 56 0 6025 0.50 301.30 1362.00 

 TITLE RLOC FAX FP FKA PRES 

RBHT_TEST_937 RodB2-38.4 0.0 0.0 0.0 20.0 

 TIME POWER TEMP 

 0.25 -0.0005 674.2396 

 0.50 -0.0005 674.1904 

 0.75 -0.0005 674.1823 

 1.00 -0.0005 674.1577 

 1.25 -0.0005 674.1331 

 1.50 -0.0005 674.0920 

 1.75 -0.0005 674.0593 

 2.00 -0.0005 674.0183 

... 

 300.00 142.3709 921.2880 

 300.25 143.8328 922.3034 

 300.50 143.3725 923.3672 

 300.75 143.2022 924.5842 

 301.00 142.5886 925.6238 

 301.25 143.2425 926.7762 

 301.50 143.3150 927.7829 

 301.75 142.7787 928.9585 

 302.00 142.9874 929.9327 

 302.25 151.4578 930.9714 

 302.50 151.2813 931.9538 

 302.75 143.6488 933.1535 

 303.00 154.7328 934.2566 

... 

 1516.00 0.0000 218.2863 

 1516.25 0.0000 218.3030 

 1516.50 0.0000 218.2947 

 1516.75 0.0000 218.2697 

 1517.00 0.0000 218.2947 

 1517.25 0.0000 218.2614 

 1517.50 0.0000 218.2531 

 1517.75 0.0000 218.2614 

 1506.50 0.0000 218.3530
50 

Sample Output File 

*********** Program DATARH - Universal Rev. 01 

 *********** Revision Date: 01-14-2010 

 *********** RBHT Test 937 

 *********** CHANNEL = 56 

 *********** Rod ID = RodB2-38.4 

 Initial Run Conditions : 

 Nunmber of data points : 6025 

 Axial Power Factor : 0.84700 

 Fraction of Zone Power to rod : 0.02222 

 Volumetric fraction of wire : 0.85212 

 System pressure : 20.00000 psi 

 System pressure : 0.13790 MPa 

 Start of relood : 301.30 sec 

 End time : 1362.00 sec 

 Output interval : 0.50 sec 

 Saturation Temperature is : 227.92000 deg. F 

 : 381.99444 K 

 Temperature at reflood : 926.96 deg F 

 Temperature at reflood : 770.36 K 

 Turn around time : 22.45 sec 

 Turn around temperature : 999.46 deg F 

 Turn around temperature : 810.64 K 

 Quench time : 156.45 sec 

 Quench temperature : 656.08 deg F 

 Quench temperature : 619.87 K 

 ************* Summary of Results ************** 

TIME TEMP TSURF QSURF HTC TIME TSURF DT QSURF HTC

sec deg F deg F Btu/hr-ft2 Btu/hr-ft2-F sec K K W/m2 W/m2-K

0.45 928.96 928.03 1.64E+03 2.34E+00 0.45 770.96 388.95 5.16E+03 1.33E+01

0.95 930.97 930.07 2.10E+03 2.99E+00 0.95 772.09 390.09 6.62E+03 1.70E+01

1.45 933.15 932.28 1.73E+03 2.45E+00 1.45 773.32 391.31 5.44E+03 1.39E+01

1.95 935.33 934.4 1.76E+03 2.50E+00 1.95 774.49 392.49 5.57E+03 1.42E+01

2.45 937.36 936.5 1.78E+03 2.51E+00 2.45 775.66 393.66 5.61E+03 1.43E+01

2.95 939.5 938.52 2.00E+03 2.81E+00 2.95 776.78 394.78 6.30E+03 1.60E+01

3.45 941.54 940.54 2.00E+03 2.81E+00 3.45 777.9 395.9 6.31E+03 1.59E+01

3.95 943.48 942.54 2.03E+03 2.84E+00 3.95 779.01 397.01 6.41E+03 1.61E+01

4.45 945.42 944.55 2.01E+03 2.80E+00 4.45 780.13 398.13 6.33E+03 1.59E+01

4.95 947.46 946.46 2.42E+03 3.36E+00 4.95 781.19 399.19 7.62E+03 1.91E+01

5.45 949.46 948.51 2.09E+03 2.90E+00 5.45 782.33 400.33 6.59E+03 1.65E+01

5.95 951.46 950.46 2.18E+03 3.02E+00 5.95 783.41 401.41 6.89E+03 1.72E+01

6.45 953.37 952.45 2.11E+03 2.91E+00 6.45 784.52 402.51 6.66E+03 1.65E+01

6.95 955.28 954.39 2.47E+03 3.40E+00 6.95 785.6 403.6 7.78E+03 1.93E+01

7.45 957.37 956.5 2.03E+03 2.79E+00 7.45 786.77 404.76 6.40E+03 1.58E+01
51 

3.1.6 Calculation of the Power Factor at Each Thermocouple Location 

Stern Laboratories, Inc. measured the resistance of each heater rod filament beginning from the 

bottom of the heated length to the end of the heated length. The measurements were made 

over increments of one tenth of the length of the rod and the cumulative resistances were 

reported. Table 3.2 shows a sample table of data from Stern. 

Table 3.2 Heater Number 1 

Length (in) Resistance (Ohm)

0 

14.28 

28.55 

42.83 

57.1 

71.38 

85.65 

99.93 

114.20 

128.48 

142.75 

0.000 

0.018 

0.040 

0.066 

0.096 

0.129 

0.166 

0.211 

0.258 

0.291 

0.315 

WINDOWS (EAST) 

Rod A1 

Support Rod 

Rod B1 

GR-7 

PSP-15

Rod C1 

GR-0 

PSP-45

Rod D1 

GR-7 

PSP-16

Rod E1 

GR-0 

PSP-48

Rod F1 

GR-0 

PSP-42

Rod G1 

Support Rod 

Rod A2 

GR-0 

PSP-40

Rod B2 

GR-1 

PSP-36

Rod C2 

GR-2 

PSP-32

Rod D2 

GR-6 

PSP-12

Rod E2 

GR-8 

PSP-6

Rod F2 

GR-1 

PSP-37

Rod G2 

GR-0 

PSP-47

Rod A3 

GR-0 

PSP-49

Rod B3 

GR-8 

PSP-27

Rod C3 

GR-5 

PSP-4

Rod D3 

GR-3 

PSP-21

Rod E3 

GR-4 

PSP-7

Rod F3 

GR-8 

PSP-28

Rod G3 

GR-0 

PSP-43

Rod A4 

GR-7 

PSP-17

Rod B4 

GR-3 

PSP-22

Rod C4 

GR-3 

PSP-23

Rod D4 

GR-3 

PSP-25

Rod E4 

GR-3 

PSP-24

Rod F4 

GR-5 

PSP-2

Rod G4 

GR-0 

PSP-44

Rod A5 

GR-0 

PSP-41

Rod B5 

GR-2 

PSP-33

Rod C5 

GR-4 

PSP-8

Rod D5 

GR-8 

PSP-29

Rod E5 

GR-4 

PSP-9

Rod F5 

GR-2 

PSP-34

Rod G5 

GR-0 

PSP-50

Rod A6 

GR-7 

PSP-18

Rod B6 

GR-1 

PSP-38

Rod C6 

GR-2 

PSP-35

Rod D6 

GR-6 

PSP-13

Rod E6 

GR-8 

PSP-30

Rod F6 

GR-1 

PSP-39

Rod G6 

GR-0 

PSP-3

Rod A7 

Support Rod 

Rod B7 

GR-0 

PSP-1

Rod C7 

GR-6 

PSP-11

Rod D7 

GR-7 

PSP-19

Rod E7 

GR-0 

PSP-46

Rod F7 

GR-7 

PSP-20

Rod G7 

Support Rod 

WINDOWS (WEST) 

Figure 3.1 RBHT Test Facility, Heater Rod Locations (Looking Down from Top). 
52 

Figure 3.1 shows the schematic of the RBHT Test Facility heater rod layout. The 7x7 bundle 

consists of 8 groups of rods as indicated by GR - # (group number), these are instrumented 

rods while GR-0 rods are un-instrumented. The PSP - # is the serial number of the rods as 

given by Stern. 

Axial Power Ratio Vs. Length for Rod F4

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

0 50 100 150

Length (in)

Power Rati

o

Figure 3.2 Axial Power Ratio for Rod F4. 

The heater rod is composed of a series of resistances along the length. The power shape is 

obtained by appropriately changing the pitch of the heater element. 

Using the data, the resistance for every incremental length (one tenth of the total length) is 

calculated by subtracting the value of resistance over the total length (0 to that axial location) 

from the previous value (0 to the previous axial location). This would give the resistance of the 

filament portion for that region (one-tenth of the total length). The incremental length over which 

the measurements are made is also calculated. 

The axial power factor is defined as the ratio of the incremental resistance for that incremental 

length over the incremental length to the total resistance of the rod over the total heated length. 

Using this definition, the axial power factor over each incremental length is calculated. 

This is plotted as a function of length to get the power shape for each rod. Since the 

measurements provided by Stern was over every tenth of the heated length, these points were 

plotted at an average axial position (for example, for the length between 14.28 and 28.55 in, the 

incremental resistance and hence the power factor over this span was plotted at a location of 

21.415 in). Such a plot is shown in Figure 3.2, for Rod F4 (Stern heater number 2) 
53 

Measurements from Stern were such that they bypassed the peak power location, meaning the 

measurement was taken at 99.93 and 114.20 in elevations. The peak power location was 108 

in. In order to calculate the power factor at the peak power location and for any arbitrary 

location along the length of the heater rod, a straight line is fit for the power factor calculated 

using the data points between 0 and 108 in. The equation for the power factor is a function of 

length along the heater rod. Using this equation, the peak power factor is calculated for each 

rod (i.e., the value of power factor is calculated at 108 in location). This is then used along with 

the remaining calculated values of power factors (for length beyond 108 in) and another such 

plot is made. An equation relating the power ratio and the heated length is obtained for the 

region beyond 108 in. Thus, for each heater rod, two plots are made, one for the length of the 

heater rod below the peak power location and the other beyond the peak power location to the 

end of the heated length. Using the equations for the power ratio as a function of axial position, 

the power factor at any location along the heater rod is obtained. 

This procedure is followed for each rod with thermocouples and the power factor for every 

thermocouple location is obtained. Table 3.3 shows a typical calculation for one rod. (The 

resistances are values before swaging.) 

Table 3.3 Sample Power Factor Calculation for One Heater Rod 

Stern Lab Heater Number 2: RBHT ROD F4

Length Increment Averaged Heater # 2 Difference Power Channel # Instrument Power 

length Length Resistance Ratio Location ratio

(in) (in) (in) Ohm Ohm THERMOCOUPLE INFORMATION

0 14.28 7.14 0 0.017 0.55 98 85.6 1.29

14.28 14.27 21.415 0.017 0.022 0.71 99 88.4 1.31

28.55 14.28 35.69 0.039 0.026 0.84 100 92.4 1.35

42.83 14.27 49.965 0.065 0.03 0.96 101 94.3 1.37

57.1 14.28 64.24 0.095 0.034 1.09 102 97.2 1.39

71.38 14.27 78.515 0.129 0.038 1.22 108 1.49

85.65 14.28 92.79 0.167 0.042 1.35 103 108.8 1.47

99.93 14.27 107.065 0.209 0.044 1.42 104 111 1.41

108 1.49

114.2 14.28 121.34 0.253 0.035 1.13

128.48 14.27 135.615 0.288 0.023 0.74

142.75 0.311

Figure 3.3 and Figure 3.4 show plots of the power ratio as a function of length along the heater 

rod. Figure 3.3 is the plot from the beginning of the heated length to the peak power location 

(108 in), while Figure 3.4 is the plot from the peak power location (108 in) to the end of heated 

length. 

 

The values of the axial power factor for all the thermocouples used in the RBHT Test Facility is 

shown in Table 3.4. The values of the axial power factors range from 0 to 1.5, which is the 

value at peak power location of 108 in. For example: RodB1_47.9 refers to the thermocouple at 
54 

47.9 in elevation for rod B1. These values are directly used in DATARH for the local rod heat 

flux and heat transfer coefficient calculations. 

y = 0.0092x + 0.4978

R2 = 0.9988

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

0 20 40 60 80 100 120

Length (in)

Power Ratio

Rod F4

TC locations

Linear (Rod F4)

Figure 3.3 Power Factor as a Function of Length (Beginning of Heated Length to 

Peak Clad Temperature Location). 

y = -0.0272x + 4.4294

R2 = 1

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

100 110 120 130 140 150

Length (in)

Power Ratio

Rod F4

TC location

Linear (Rod F4)

Figure 3.4 Power Factor as a Function of Length (From Peak Clad Temperature 

Location to the End of Heated Length). 
55 

Table 3.4 Axial Power Factors for the RBHT Heater Rods 

Rod ID Elevation 

(inches)

Power 

Factor

Rod ID Elevation 

(inches)

Power 

Factor

Rod ID Elevation 

(inches)

Power 

Factor

RodB1_47.9 0.936 RodE2_66 1.111 RodF3_54 0.993

RodB1_63.6 1.082 RodE2_69.8 1.147 RodF3_57 1.022

RodB1_68.6 1.128 RodE2_72.9 1.176 RodF3_60 1.05

RodB1_79.7 1.231 RodE2_74.9 1.195 RodF3_66.1 1.108

RodB1_97.1 1.393 RodF2_4.1 0.519 RodF3_69.9 1.145

RodB1_114.8 1.314 RodF2_11.2 0.586 RodF3_73 1.174

RodB1_126.7 0.99 RodF2_16.2 0.634 RodF3_75 1.193

RodB1_139.4 0.644 RodF2_23.3 0.701 RodA4_48 0.94

RodD1_47.9 0.941 RodF2_29.2 0.757 RodA4_63.8 1.084

RodD1_63.8 1.093 RodF2_33.3 0.796 RodA4_68.8 1.13

RodD1_68.8 1.141 RodF2_35.3 0.815 RodA4_79.9 1.231

RodD1_79.9 1.248 RodF2_38.3 0.843 RodA4_97.1 1.387

RodD1_97.3 1.415 RodB3_50.2 0.956 RodA4_115 1.291

RodD1_115 1.317 RodB3_54.1 0.992 RodA4_126.8 0.977

RodD1_126.6 0.99 RodB3_56.9 1.018 RodA4_139.4 0.642

RodD1_139.4 0.629 RodB3_60.1 1.048 RodB4_88.4 1.303

RodB2_4.1 0.521 RodB3_66.1 1.104 RodB4_91.3 1.329

RodB2_11.2 0.589 RodB3_69.9 1.139 RodB4_93.3 1.347

RodB2_16.2 0.636 RodB3_73 1.168 RodB4_95.1 1.363

RodB2_23.3 0.704 RodB3_75 1.187 RodB4_100 1.407

RodB2_29.3 0.761 RodC3_79.8 1.228 RodB4_106 1.461

RodB2_33.3 0.799 RodC3_85.6 1.281 RodB4_109.9 1.414

RodB2_35.3 0.818 RodC3_88.5 1.308 RodB4_142.3 0.549

RodB2_38.4 0.847 RodC3_92.4 1.344 RodC4_88.4 1.328

RodC2_41 0.87 RodC3_94.4 1.362 RodC4_91.1 1.354

RodC2_53.1 0.983 RodC3_97.2 1.388 RodC4_93.4 1.376

RodC2_55 1 RodC3_108.8 1.463 RodC4_95.3 1.394

RodC2_57.8 1.026 RodD3_88.3 1.313 RodC4_100.1 1.439

RodC2_63.9 1.083 RodD3_91.3 1.341 RodC4_106.1 1.496

RodC2_73.8 1.175 RodD3_93.1 1.358 RodC4_110 1.448

RodC2_75.8 1.194 RodD3_95.3 1.378 RodC4_142.2 0.553

RodC2_76.8 1.203 RodD3_100.1 1.423 RodD4_88.3 1.323

RodD2_103.2 1.455 RodD3_106.1 1.479 RodD4_91.3 1.351

RodD2_106 1.481 RodD3_110 1.46 RodD4_93.2 1.369

RodD2_112.6 1.358 RodD3_142.1 0.51 RodD4_95.2 1.388

RodD2_114.9 1.295 RodE3_63.4 1.079 RodD4_100.1 1.434

RodD2_117.4 1.227 RodE3_113.6 1.331 RodD4_106.1 1.491

RodD2_120.8 1.134 RodE3_115.5 1.281 RodD4_110 1.44

RodD2_124.8 1.024 RodE3_118.5 1.203 RodD4_142.1 0.534

RodD2_128.6 0.92 RodE3_122.7 1.094 RodE4_88.4 1.303

RodE2_50.1 0.962 RodE3_126.5 0.995 RodE4_91.2 1.329

RodE2_54 0.998 RodE3_131.7 0.86 RodE4_93.2 1.347

RodE2_56.9 1.025 RodE3_135.6 0.759 RodE4_95.3 1.365

RodE2_59.9 1.054 RodF3_50.1 0.956 RodE4_100.9 1.416
56 

Table 3.4 Axial Power Factors for the RBHT Heater Rods (Continued) 

Rod ID Elevation 

(inches)

Power 

Factor

Rod ID Elevation 

(inches)

Power 

Factor

Rod ID Elevation 

(inches)

Power 

Factor

RodE4_106.1 1.463 RodF5_57.8 1.022 RodE6_75 1.184

RodE4_110 1.428 RodF5_64 1.08 RodF6_4.1 0.528

RodE4_142.3 0.54 RodF5_73.8 1.171 RodF6_11.2 0.593

RodF4_85.6 1.285 RodF5_75.8 1.19 RodF6_16.3 0.639

RodF4_88.4 1.311 RodF5_76.8 1.199 RodF6_23.3 0.703

RodF4_92.4 1.348 RodA6_47.7 0.942 RodF6_29.3 0.757

RodF4_94.3 1.365 RodA6_63.6 1.085 RodF6_33.3 0.794

RodF4_97.2 1.392 RodA6_68.5 1.129 RodF6_35.3 0.812

RodF4_108.8 1.47 RodA6_79.8 1.231 RodF6_38.3 0.839

RodF4_111 1.41 RodA6_97.4 1.389 RodC7_112.6 1.323

RodB5_41 0.872 RodA6_115.1 1.29 RodC7_116.6 1.224

RodB5_52.9 0.982 RodA6_126.6 0.986 RodC7_124.4 1.03

RodB5_55 1.002 RodA6_139.9 0.633 RodC7_128.4 0.931

RodB5_57.8 1.028 RodB6_4.1 0.526 RodD7_47.9 0.948

RodB5_64 1.085 RodB6_11.2 0.592 RodD7_63.6 1.091

RodB5_73.9 1.177 RodB6_16.2 0.638 RodD7_68.8 1.138

RodB5_75.9 1.196 RodB6_23.3 0.703 RodD7_79.8 1.238

RodB5_76.9 1.205 RodB6_29.3 0.758 RodD7_97.1 1.396

RodC5_63.7 1.059 RodB6_33.3 0.795 RodD7_114.9 1.293

RodC5_113.6 1.298 RodB6_35.3 0.813 RodD7_126.7 0.958

RodC5_115.7 1.246 RodB6_38.4 0.842 RodD7_139.4 0.598

RodC5_122.7 1.073 RodC6_40.9 0.866 RodF7_47.9 0.946

RodC5_126.7 0.974 RodC6_52.8 0.981 RodF7_63.8 1.101

RodC5_131.6 0.853 RodC6_54.8 1.001 RodF7_68.9 1.15

RodC5_135.7 0.752 RodC6_57.8 1.03 RodF7_79.9 1.257

RodD5_50 0.959 RodC6_63.8 1.088 RodF7_97.2 1.425

RodD5_54.1 0.996 RodC6_73.7 1.184 RodF7_114.9 1.333

RodD5_56.9 1.022 RodC6_75.8 1.204 RodF7_126.8 0.953

RodD5_60 1.051 RodC6_76.8 1.214 RodF7_139.4 0.551

RodD5_66.1 1.107 RodD6_103.1 1.457

RodD5_69.9 1.142 RodD6_106 1.484

RodD5_72.9 1.169 RodD6_112.9 1.354

RodD5_74.9 1.188 RodD6_114.9 1.298

RodE5_63.6 1.085 RodD6_116.8 1.246

RodE5_113.6 1.339 RodD6_120.9 1.132

RodE5_115.4 1.292 RodD6_124.8 1.024

RodE5_118.7 1.208 RodD6_128.7 0.916

RodE5_122.6 1.108 RodE6_50.2 0.956

RodE5_126.6 1.006 RodE6_54.1 0.992

RodE5_131.6 0.878 RodE6_57 1.018

RodE5_135.6 0.775 RodE6_60.2 1.048

RodF5_41 0.866 RodE6_66.1 1.102

RodF5_53.1 0.978 RodE6_70 1.138

RodF5_55 0.996 RodE6_73.1 1.166
57 

3.2 Quench Front Determination

A simple program was developed and added to the DATARH source code to determine the 

quench front progress for the RBHT reflood experiments. As a result of the program, the 

location of the quench front as a function of time is obtained. 

The quench front program uses the outside rod temperatures predicted by DATARH, locations 

of these temperatures, and the test time as input. The reflood start time is the starting time for 

the program. The program runs as part of DATARH and outputs results in the same output file 

as seen in the sample output file presented above. 

A simple criterion is used to determine the quench front location from the heated rod 

temperature data. One sample of plot for change in rod temperature with time is presented in 

Figure 3.5 and quench time is indicated on the figure. 

0

100

200

300

400

500

600

700

800

900

0 200 400 600 800 1000 1200 1400 1600 1800 2000

time (sec)

Temperature (C)

rod 

quenches

P = 137.9 kPa (20 psia)

Inlet Flooding = 0.0254 m/s (1.0 in/s)

Peak Power = 1.31 kW/m (0.4 kW/ft)

Initial Temperature = 760.0 C (1400 F) 

Inlet Subcooling = 11.1 C (20 F)

Figure 3.5 Clad Temperature at 2.24 m, Experiment 1096. 

The first attempt to determine the quench front time was to use a simple numerical approach to 

get the first derivative for the above data. The time at which the first derivative reaches its 

maximum value was assumed as the quench time since the rate of change of the heater rod 

temperature would be the greatest. 
58 

Equation (3-28) gives the relationship used to evaluate the first derivative from the heater rod 

data: 

t

T T T

dt

dT i i i

Δ

− + = +1 −1 2 (3-28) 

where in the program, Δt is the variable DT defined in the input file datarhin.dat and Ti+1, Ti, Ti-1

are predicted heater rod outside surface temperatures from DATARH predictions. 

Figure 3.6 presents the change in the first derivative of temperature with respect to reflood time 

on two different scales. The figure shows that the first derivative reaches its maximum value 

approximately 10 s after rod quenches. In order to obtain a more accurate value of the quench 

time, an additional requirement was added to the program. This requirement determines the 

quench time when the first derivative of temperature versus time curve is greater than 11.1 

degrees K/s (20.0 degrees F/s). The value of 11.1 degrees K/s (20 degrees F/s) was 

determined by examining most of the rod temperature data for all tests and several elevations, 

although this value is set to 28 degrees K/s (50 degrees F/s) in FLECHT-SEASET analysis (Ref. 

1), since the data recording frequency in RBHT tests is smaller (10 samples/s, in FLECHTSEASET it was 2 samples/s or less), 11.1 degrees K/s (20.0 degrees F/s) is a suitable criterion 

for these tests. 

For the case illustrated in Figure 3.6, the quench time was determined to be 892 s, and the 

quench temperature for this case is 618 degrees K (653 degrees F). 

Figure 3.7 and Figure 3.8 present samples of calculations performed to analyze quench front 

progress. 

As a result of the program, the rod surface temperature at the quenched elevation is also 

obtained. Figure 3.9 and Figure 3.10 present the data for quenched temperature versus 

elevation for experiments 1096 and 1383, respectively. As the figures show, the quench 

temperature data follows a distribution. The mean quench temperatures and standard deviation 

for these mean temperatures are also presented in the figures. The mean quench temperature 

for the reference (40 psia) experiment was found to be 694 degrees K (789 degrees F) and for 

the reference (20 psia) experiment the mean quench temperature was found to be 667 degrees 

K (741 degrees F). 

The quench front program developed for rods was also used to determine the quench front 

progress for the bundle housing to prepare an input for the energy balance programs to 

calculate housing heat release. Figure 3.11 and Figure 3.12 present the housing quench front 

locations versus time for experiments 1096 and 1383, respectively. 

The quench front locations for the housing and the rods are shown in Figure 3.13 and Figure 

3.14 for the reference experiments. Since the housing is an unpowered structure, it quenches 

slightly earlier than the heated rods. The figures show that housing and rods quench almost at 

the same time up to 2 m (6.5 ft) elevation and the peak clad temperature turnaround occurs 

during this period. This indicates that the housing quench does not affect the turnaround time 

for the heater rods. At the higher elevations, the difference between quench time of the heater 

rods and housing does increase.
59 

0

50

100

150

200

250

300

350

400

860 870 880 890 900 910 920 930 940

time (sec)

Temperature (C)

0

10

20

30

40

50

60

70

80

DT/dt

temperature

first derivative

rod quenches

P = 137.9 kPa (20 psia)

Inlet Flooding = 0.0254 m/s (1.0 in/s)

Peak Power = 1.31 kW/m (0.4 kW/ft)

Initial Temperature = 760.0 C (1400 F) 

Inlet Subcooling = 11.1 C (20 F)

Figure 3.6 Temperature and First Derivative of Temperature at 2.24 m, 

Experiment 1096. 

0

100

200

300

400

500

600

700

800

900

0 200 400 600 800 1000 1200

time (sec)

Temperature (C)

0

10

20

30

40

50

60

70

80

Dt/dt

temperature

first derivative

rod quenches

P = 137.9 kPa (20 psia)

Inlet Flooding = 0.0254 m/s (1.0 in/s)

Peak Power = 1.31 kW/m (0.4 kW/ft)

Initial Temperature = 760.0 C (1400 F) 

Inlet Subcooling = 11.1 C (20 F)
60 

0

50

100

150

200

250

300

350

400

900 910 920 930 940 950 960 970 980 990 1000

time (sec)

Temperature (C)

0

10

20

30

40

50

60

70

80

90

100

DT/dt

temperature

first derivative

rod quenches

P = 137.9 kPa (20 psia)

Inlet Flooding = 0.0254 m/s (1.0 in/s)

Peak Power = 1.31 kW/m (0.4 kW/ft)

Initial Temperature = 760.0 C (1400 F) 

Inlet Subcooling = 11.1 C (20 F)

Figure 3.7 Temperature and First Derivative of Temperature Curve at 2.42 m, 

Experiment 1096. 

0

100

200

300

400

500

600

700

800

900

0 200 400 600 800 1000 1200

time (sec)

Temperature (C)

0

10

20

30

40

50

60

70

80

90

100

DT/dt

temperature

first derivative

rod quenches

P = 137.9 kPa (20 psia)

Inlet Flooding = 0.0254 m/s (1.0 in/s)

Peak Power = 1.31 kW/m (0.4 kW/ft)

Initial Temperature = 760.0 C (1400 F) 

Inlet Subcooling = 11.1 C (20 F)
61 

0

50

100

150

200

250

300

350

400

450

500

450 460 470 480 490 500 510 520 530 540 550

time (sec)

Temperature (C)

0

20

40

60

80

100

120

140

160

DT/dt

temperature

first derivative

rod quenches

P = 275.8 kPa (40 psia)

Inlet Flooding = 0.0254 m/s (1.0 in/s)

Peak Power = 1.31 kW/m (0.4 kW/ft)

Initial Temperature = 760.0 C (1400 F) 

Inlet Subcooling = 11.1 C (20 F)

Figure 3.8 Temperature and First Derivative of Temperature Curve at 2.42 m, 

Experiment 1383. 

0

100

200

300

400

500

600

700

800

900

0 100 200 300 400 500 600 700 800

time (sec)

Temperature (C)

0

20

40

60

80

100

120

140

160

DT/dt

temperature

first derivative

rod quenches

P = 275.8 kPa (40 psia)

Inlet Flooding = 0.0254 m/s (1.0 in/s)

Peak Power = 1.31 kW/m (0.4 kW/ft)

Initial Temperature = 760.0 C (1400 F) 

Inlet Subcooling = 11.1 C (20 F)
62 

1

2

3

4

350 370 390 410 430 450 470 490

Quench Temperature (C)

number

average temperature = 393.75 C = 740.75 F

standard deviation = 39.52 C

P = 137.9 kPa (20 psia)

Inlet Flooding = 0.0254 m/s (1.0 in/s)

Peak Power = 1.31 kW/m (0.4 kW/ft)

Initial Temperature = 760.0 C (1400 F) 

Inlet Subcooling = 11.1 C (20 F)

Figure 3.9 Quench Temperature at Different Quench Locations, Experiment 1096. 
63 

1

2

3

4

350 370 390 410 430 450 470 490

Quench Temperature (C)

number

average temperature = 420.5 C = 788.9 F

standard deviation = 22.9 C

P = 275.8 kPa (40 psia)

Inlet Flooding = 0.0254 m/s (1.0 in/s)

Peak Power = 1.31 kW/m (0.4 kW/ft)

Initial Temperature = 760.0 C (1400 F) 

Inlet Subcooling = 11.1 C (20 F)

Figure 3.10 Quench Temperature at Different Quench Locations, Experiment 1383. 

0

0.5

1

1.5

2

2.5

3

3.5

4

0 200 400 600 800 1000 1200 1400

time (sec)

axial distance (m)

0

20

40

60

80

100

120

140

160

axial distance (inch)

P = 137.9 kPa (20 psia)

Inlet Flooding = 0.0254 m/s (1.0 in/s)

Peak Power = 1.31 kW/m (0.4 kW/ft)

Initial Temperature = 760.0 C (1400 F) 

Inlet Subcooling = 11.1 C (20 F)

Figure 3.11 Housing Quench Front, Experiment 1096. 
64 

0

0.5

1

1.5

2

2.5

3

3.5

4

0 100 200 300 400 500 600 700 800

time (sec)

axial distance (m)

0

20

40

60

80

100

120

140

160

axial distance (inch)

P = 275.8 kPa (40 psia)

Inlet Flooding = 0.0254 m/s (1.0 in/s)

Peak Power = 1.31 kW/m (0.4 kW/ft)

Initial Temperature = 760.0 C (1400 F) 

Inlet Subcooling = 11.1 C (20 F)

Figure 3.12 Housing Quench Front, Experiment 1383. 

0

0.5

1

1.5

2

2.5

3

3.5

4

0 200 400 600 800 1000 1200 1400 1600

time (sec)

axial distance (m)

0

20

40

60

80

100

120

140

160

axial distance (inch)

bundle qf

housing qf

P = 137.9 kPa (20 psia)

Inlet Flooding = 0.0254 m/s (1.0 in/s)

Peak Power = 1.31 kW/m (0.4 kW/ft)

Initial Temperature = 760.0 C (1400 F) 

Inlet Subcooling = 11.1 C (20 F)

Figure 3.13 Rod and Housing Quench Front, Experiment 1096. 
65 

0

0.5

1

1.5

2

2.5

3

3.5

4

0 100 200 300 400 500 600 700 800 900

time (sec)

axial distance (m)

0

20

40

60

80

100

120

140

160

axial distance (inch)

bundle qf

housing qf

P = 275.8 kPa (40 psia)

Inlet Flooding = 0.0254 m/s (1.0 in/s)

Peak Power = 1.31 kW/m (0.4 kW/ft)

Initial Temperature = 760.0 C (1400 F) 

Inlet Subcooling = 11.1 C (20 F)

Figure 3.14 Rod and Housing Quench Front, Experiment 1383. 

3.3 RBHT Mass Balance

3.3.1 Introduction 

As part of the validation of the experiments performed at the RBHT test facility, it was necessary 

to perform a mass balance using the experimental data. A Fortran program was written to read 

the output data files and perform the mass balance calculations. The program incorporates 

steam tables used for calculating density and is input-deck driven, which allows for flexibility in 

changing key parameters such as the facility dimensions. Finally, the program outputs the 

finished mass balance information for easy plotting and analysis. 

3.3.2 Methodology 

 

In order to calculate the mass balance for the rod bundle test loop it is necessary to determine 

the locations where mass is stored and where mass flow rate measurements should be taken. 

For the rod bundle test loop, the elements needed to make up the mass balance are 

summarized as follows: 











 =













+













+













+













Flow

Inlet Mass

Mass Flow

Steam Outlet

MassStorage

Upper Plenum

Tanks MassStorage

Drain & Carryover

in the Bundle

MassStorage

 

The mass storage in the bundle is calculated using the overall pressure drop in the bundle. The 

calculation can be done one or two ways. First, it can be done by simply considering the overall 
66 

pressure drop in the bundle and calculating the mass storage directly from this value using the 

cross-sectional area of the bundle. This approach calculates the mass storage, where there is 

no pressure drop correction due to acceleration or friction and may tend to be an over-estimate 

of the mass storage. The second method is more involved and includes a frictional pressure 

drop correction of the overall pressure drop. The frictional pressure drop component is made up 

of friction from both the rods and grids. Acceleration pressure drop is ignored. 

It was found for the calculations when the frictional pressure drop was considered; it caused the 

mass storage in the bundle to be much lower than expected. This is probably due to models for 

grid and rod friction that were used and the calculation method. However, when only the overall 

pressure drop was used, the agreement between the expected and predicted bundle mass 

storage was improved. Although the frictional pressure calculation is still included in the mass 

balance code for completeness, for all results presented in this report the friction calculation was 

turned off. 

The mass storage in each of the tanks (small and large carryover tanks and drain tank) was 

calculated from the liquid elevation, taken from a differential pressure cell, and the crosssectional area of the tank. The differential pressure cells were calibrated at standard conditions 

and reported in inches of H2O. The liquid head is taken directly from this reading and the mass 

storage is calculated as the product of the liquid head, the density at STP, and the cross 

sectional area of the tank. 

The upper plenum mass storage calculation is done very differently from the rest. The reason 

for this is that there are no direct indicators of the liquid level in the upper plenum. 

Consequently, an estimate of the liquid level must be made. To achieve this, the upper plenum 

is assumed to begin filling when the large carryover tank has already filled. Also, the liquid flow 

rate into the plenum is assumed to be constant and equal to the flow rate into the large 

carryover tank for the few seconds before it is filled. For the mass balanced performed, the 

estimate fits the expected values quite well. 

When the upper plenum fills liquid overflows into the steam separator drain tank, as indicated by 

an increase in the rate at which the tank is filling. This additional flow into the drain tank is 

assumed to be at the same rate at which the large carryover tank and upper plenum are filled. 

Eventually, liquid carryover from the steam separator drain tank begins to fill the pressure 

oscillating tank. This tank does not have a level indicator, however, the liquid is drained from 

the tank and weighed when the test concludes. In performing the transient mass balance, it is 

assumed that the rate of liquid collection is the same as the rate at which the steam separator 

drain tank is filled. In some of the shorter reflood tests, no water was collected in the pressure 

oscillating tank. 

The steam flow from the facility was calculated simply from the measured steam flow and the 

density at the exit. A thermocouple and a pressure transducer near the exit of the exhaust 

allowed the density to be calculated. Using the density and volumetric flow rate from the 

exhaust line, the mass flow rate could be calculated. In experiments where the exhaust flow 

meter was over-ranged, for example 1143, a calculation was performed using a relationship of 

pressure drop to flow rate developed from other experimental data. The pressure drop data 

was then used to calculate an exhaust flow rate. 
67 

Finally, each of the mass accumulations calculated so far must sum together to equal the mass 

flowed into the bundle at the inlet. For some experiments the inlet mass flow was calculated 

using the level and density of the water in the supply tank. (This method was used rather than 

the direct measurement of flow rate because of an error found in the inlet flow meter reading. 

Although the problem with the flow meter did not emerge until later in the test series, each test 

was re-calculated using the supply tank measurement). The change in the mass storage of the 

supply tank is equal to the mass injected into the bundle. The mass storage in the supply tank 

is calculated the same as the mass accumulation in the carryover and drain tanks. The liquid 

level is reported as inches of H2O and the cross-sectional area and standard density are known. 

The only slight difference between this calculation and the calculation of the mass accumulation 

in the other tanks is that this tank has a cross-sectional area that varies with elevation. A table 

of cross-section area was used in the program to determine the tank cross-sectional area 

depending on the liquid elevation. 

The mass balance must be concluded when either the drain or large carryover tank is filled. 

After this point, an accurate estimation of mass accumulation cannot be performed. The mass 

imbalance is calculated as the difference in the total inlet mass and the sum of all of the other 

contributions at then end of the experiment or when the drain or large carryover tank is filled. 

The percent of mass imbalance is calculated as this difference divided by the total inlet mass. 

In general, the mass imbalance was greater for higher flooding rate tests. 

3.3.3 Summary of Mass Imbalances 

Figure 3.15 gives a summary of the mass imbalance for each of the RBHT experiments. In 

general, the calculation of the mass balance agrees within five percent of the injected mass for 

most of the experiments. The exceptions are two experiments with more than 15 percent 

imbalance, and three experiments with a mass imbalance of more than 10 percent. The two 

experiments with the greatest imbalance were both high flooding rate cases (6 in/s). One 

possible explanation for this imbalance occurring for high flooding rates is that some liquid was 

able to pass through the steam separator and out of the facility with the steam flow or it was 

collected in the pressure damping tank and was not measured. The exit flow rate from the 

facility is calculated bases on the properties of steam, so this extra liquid flow would be 

unaccounted for. In addition, the short duration of these runs may cause additional error due to 

transient effects that would not be as pronounced in longer duration runs, such as liquid storage 

in facility piping and equipment. Individual mass balance calculations for each experiment are 

given in the next section and the details of the mass balance program. 
68 

Percent Mass Imbalance vs. Experiment Number

2.12

1.24

2.01

14.67

2.84

1.47

0.3

13.3

7.35

1.66

4.34

6.35

5.41

6.29

9.58

7.36

12.69

0.5 0.4

2.44

0.86

0.24

3.02

4.77

0

5

10

15

20

937

945

973

1088

1096

1108

1143

1155

1160

1170

1196

1202

1223

1228

1280

1285

1291

1295

1300

1310

1319

1383

1389

1402

1407

Percent Mass Imbalance

Experiment Number

Figure 3.15 Summary of Mass Imbalances. 

3.3.4 Transient Mass Balance 

3.3.4.1 Bundle Inlet Mass 

The bundle inlet mass flow is calculated from the level in the supply tank. Table 3.5 lists the 

parameters required for calculating the mass flow rate from the level in the supply tank. The 

supply tank cross-sectional area is taken from the facility design description report and is 

calculated as a function of elevation. A look-up and interpolation table is include in the code 

and follows the cross-sectional area profile in Figure 3.16. 

Table 3.5 Supply Tank Parameters 

Description Location Base Units Fortran Variable

Supply Tank Level Supply Tank (0-119 in) in H2O suplvl 

Supply Tank Area Supply Tank in2 suparea 

Supply Tank Pressure Supply Tank psig suppr 

Supply Tank Liquid Temp. Supply Tank (bottom) degrees F suptmp 

Supply Tank Liquid Dens. Supply Tank (bottom) lbm/ft3

 rhotk 

Supply Line Pressure Supply Line (after valve) psig suppr 

Supply Line Liquid Temp. Supply Line (after valve) degrees F suptmp 

Supply Line Liquid Dens. Supply Tank (after valve) lbm/ft3

 rho 
69 

Supply Tank Area

0

50

100

150

200

250

300

350

400

450

500

0 20 40 60 80 100 120 140

Elevation (in)

Cross-sectional Area (in2

)

Figure 3.16 Supply Tank Cross-Sectional Area. 

The temperature and pressure parameters were taken directly from the data acquisition output 

data and are used to calculate the density at the corresponding location using an algorithm 

based on “Properties of Water and Steam in SI-Units,” 2nd Revised and Updated Printing, 

Springer 1979, and written in 1998 by Bernhard Spang of The Mining Company. 

In order to determine the flow rate from the supply tank, it is first necessary to determine the 

correct change in level. The level transducer for the supply tank measures the level as if it were 

water at STP. This is a key point. If the water in the supply tank is not at standard conditions, 

a correction must be made to calculate the correct change in level. This is done by correcting 

the level by the ratio of densities at STP and tank conditions respectively. 

tank

corrected measured

ρ

ρ STP ΔL = ΔL ⋅

 (3-29) 

Next, multiplying this corrected level change by the cross sectional area of the tank at that 

elevation will give the volumetric displacement. 

V L A ( ) x corrected tank Δ = Δ ⋅ (3-30) 
70 

Since the volume is coming from the conditions in the tank, the mass displaced should be 

calculated from the density at that location. 

tank

~

m = ΔV ⋅ ρ (3-31)

Now, simplifying the expression for the mass, we see that the tank density is no longer 

considered. 

m L A ( ) x measured STP tank

~ = Δ ⋅ ρ ⋅ (3-32) 

This mass represents the additional mass supplied over the length of time that ΔL is 

determined. The level is reported as in H2O, and the change in level gives the mass decrease 

in the tank over time. The decrease in supply tank mass is the mass supplied to the bundle. 

The mass flowed into the bundle between two times is: 

 

( ) ()sup.tk. m P P A z inlet t t t STP = Δ − Δ ⋅ ⋅ −Δ ρ (3-33) 

where ( )sup.tk. A z is the area of the supply tank, which is a function of the water level. 

3.3.4.2 Steam Exhaust 

The exhaust steam flow is reported in the output file as ft3

/min. 

The mass flowing from the exhaust (lbm) is given as: 

m VT exh exh exh = Δ ρ  (3-34) 

where the density is calculated from the temperature and pressure at the exhaust. 

3.3.4.3 Large and Small Carryover Tanks and Drain Tank 

The mass storage (lbm) in the tanks is calculated by the liquid head in the tank and the crosssectional area of the tank. The liquid head is reported as inH20 and the density of reference is 

the density at STP. Therefore, the mass of liquid in the tank is simply calculated as: 

mtank = ΔPtank ρ STP Atank (3-35) 

This mass will be cumulative at each time. This calculation is done for the small and large 

carryover tanks and the drain tank. 

3.3.5 Mass Storage in the Bundle 

To calculate the mass storage in the bundle the elevation pressure drop must be isolated from 

the overall pressure drop. The acceleration pressure drop will be ignored, so the frictional 
71 

pressure drop across each grid and for the rods must be calculated. In order to do this, the 

quench front information must be entered to the code in the form of an input deck with as few or 

as many points as is necessary to describe the quench front behavior. The code then uses 

those points to generate a polynomial of the desired order to describe the quench front elevation 

over time. Using this polynomial, the code determines at each time step whether the quench 

front has reached any given grid location. If the quench front has not reached the grid, the 

pressure drop is calculated for that grid. 

First, the velocity must be found so that the Reynolds number can be calculated. This is done 

using the exit volumetric flow rate. 

vap grid

exit

exit A

V V

ρ

ρ =  (3-36) 

where 

Agrid 877Abundle = 0. 

The Reynolds number can now be calculated. 

vap

vapVDh

μ

ρ Re = (3-37) 

The k value for the grid is taken as a polynomial function of Reynolds number. 

6.965 10 Re 5.222 10 Re 1.456 10 Re 3.249 14 3 9 2 4 = − × + × − × + − − −

grid k (3-38) 

The frictional pressure drop over the grid can now be calculated by 

c

grid vap

grid g

k V

P

2

2 ρ Δ = (3-39) 

The pressure is taken at the location closest to the grid and the temperature is taken as the 

largest of the three grid thermocouples in the flow. 

The frictional pressure drop over the rods is calculated by a correlation by Wantland (Ref. 2(

) 

which gives the rod friction factor as 

0.39 Re

0.44 f = (3-40) 

Then, the rod frictional pressure drop is 
72 

c

vap

h

rods

g

V

D

L P f 2

2 ρ Δ = (3-41) 

Where L is the length of the rods above the quench front. 

The elevation pressure drop is calculated by subtracting the frictional pressure drops from the 

overall pressure drop. 

ΔPelev = ΔPtot −ΔPgrid − ΔProds (3-42) 

Finally, the mass storage in the bundle is calculated by 

g

g

m A P c

bundle = bundleΔ elev (3-43) 

A sample of mass balance calculation is presented in Figure 3.17. For the valid experiments, 

the results of the mass balance calculations are presented in Quick Look Reports. 

Mass Balance Exp. 1383

0

20

40

60

80

100

120

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

Mass (kg)

Bundle Inlet (Supply Line)

Large Carryover Tank

Small Carryover Tank

Seperator Drain Tank

Exhaust Steam

Bundle Storage

Upper Plenum

SS Housing/Accumulator

Mass Inventory

Figure 3.17 Mass Balance Plot for Experiment 1383. 
73 

3.4 Droplet Measurements

3.4.1 Droplet Measurement Instrumentation 

The method of analyzing the droplet distributions in the rod bundle involves the use of a system 

known as VisiSizer, shown in Figure 3.18 and Figure 3.19, which is capable of real-time 

analysis of droplet size and velocity distributions. The system consists of a high-resolution 

digital camera, infrared laser, data analysis software, and associated computer and control 

equipment. 

The camera, a Kodak MegaplusTM digital camera, has a resolution of over 1.0 megapixels. The 

laser system incorporates an infrared beam of wavelength 805 nm and is capable of pulsing at 

frequencies up to 1000 Hz. The laser can also pulse twice during a single camera frame to 

produce a double image used in determining velocity information. The beam of the laser is 

scattered with an opaque sheet of plastic to produce uniform background lighting for imaging. 

The system captures high-resolution images of the injection streams and analyzes the images 

at a rate of about 7 frames per second, identifying droplets as dark images in front of the laserilluminated scattering sheet. The diameter of each droplet is determined automatically by 

referencing the number of dark pixels in the droplet image to the pixel area of a calibration 

circle. 

A variety of user-defined parameters control the counting of the droplets, including focus 

rejection and sphericity criteria. Those data that do not meet the user set criteria are rejected. 

Focus rejection is determined by considering the sharpness of the droplet image by quantifying 

the intensity gradient at the outer edge of the droplet. In addition, the droplet analysis duration 

can be controlled by elapsed time, number of frames, or number of droplets counted. The 

software also calculates real-time statistics such as the mean and Sauter-mean diameters as 

well as displays the diameter distribution and, if applicable, the velocity distribution. Velocity is 

determined by double-pulsing the laser to capture the motion of a droplet. Analysis of the 

velocity is done automatically using criteria such as direction of motion, velocity range, and size 

matching. 

The test setup for this analysis involves positioning the camera such that the view is through the 

quartz windows on the sides of the facility housing. The laser is placed opposite to the housing 

such that it provides a backlighting through the rod bundle. The size of the area imaged is large 

enough for only two subchannels to be analyzed for each position of the camera. A general 

schematic of the camera setup is shown in Figure 3.18. 

It can also be seen in Figure 3.18 that the size of the probe volume will not be bounded by the 

edges of the rods at the focal plane. The width of the focal plane will be smaller than the gap 

size due to the parallax of viewing through the depth of the rod bundle. Figure 3.19 is an 

example of the image produced when viewing through the bundle, where the black images are 

the heater rods and the light image is the gap between the rods. The center of the image is the 

row of rods directly in front of the camera and the white regions are the row of gaps on either 

side of the rod. The width of the probe volume will be a function of the distance of the camera 

from the rod bundle. It is also important to note that fuzzy borders produced by out-of-focus 

rods in the image decrease the width of the probe volume even more. The variation of the gap 

size in the image is due to the difficulty in aligning the camera to a high degree of precision. For 
74 

the experiments presented here, the width of the focal plane is approximately 2.16 mm (0.085 

in), which is about 70 percent of the overall gap width. 

Figure 3.18 General Schematic of the Imaging System. 

Figure 3.19 Typical VisiSizer Image Through the Rod Bundle (No Droplets Present). 

The depth of the probe volume is also dependent on the distance of the camera from the 

bundle, but more directly on the focus rejection setting. The focus rejection setting is used to 
75 

reject droplets that appear out-of-focus due to their distance from the focal plane. In the 

experiments presented here this depth is approximately 5 mm. 

The imaging system is calibrated using a small calibration reticule. The system is trained and 

focused on the reticule which is attached to a quartz window on the housing. Using the known 

size of the calibration circles on the reticule, the distance can be determined between the 

camera and the quartz window using a calibration curve that was developed. The camera can 

then be focused on the center of the desired subchannel in the bundle by adjusting the focus 

setting to the desired new distance from the camera. 

A very detailed set of characterization and calibration bench tests separate from the rod bundle 

experiments were performed on the VisiSizer system. These bench tests helped determine the 

effects of the various rejection parameters on the droplet data acquisition as well as define the 

functional range and effectiveness of the system. 

3.4.2 Droplet Size Measurements 

For each test in the matrix a series of droplet measurements were taken at a single elevation. 

Runs were divided into ten-second periods in which droplet sizes were measured. For each of 

the ten-second period statistics were performed and the results were plotted as a function of 

both time and the quench front elevation. 

It should be noted that the droplet diameters measured in these experiments are lower than 

those found in the FLECHT-SEASET series of tests. A number of causes may have contributed 

to a smaller droplet diameter for the RBHT tests. 

The bias of the measuring technique to smaller droplets can be caused by the difference in 

behavior of large droplets compared to small droplets. First, the image of a large droplet is 

more likely to be overlapping with the image of a heater rod. The VisiSizer system is not able to 

determine the size of a droplet that is touching a rod because the entire droplet is not visible and 

it cannot distinguish the droplet image from that of the rod. In addition, images of larger droplets 

are more likely to be overlapping with images of other droplets. If the two droplet images are 

overlapping and offset, then both droplets in the overlapped area will be seen as a single droplet 

and will be rejected due to the spherosity criteria. Finally, larger droplets may also tend to be 

less spherical than small droplets. This causes the large droplets to be more likely to be 

rejected by the spherosity criteria even if it is in-focus and not overlapping any other droplet 

images. 

3.4.3 Droplet Size and Elevation 

The size of the droplets present in the rod bundle is dependent on the elevation for two reasons. 

First, droplets will tend to evaporate as they travel upward in the bundle with the superheated 

steam flow. Also, the droplets may impact on spacer grids and shatter into smaller droplets. 

These effects can be seen on the diameter distributions of the droplets measured with the 

VisiSizer system. 

In the preliminary shakedown reflood testing, the VisiSizer system was used to determine the 

effect of spacer grids on the diameters of droplets. The elevations within the bundle were 

approximately 2.74 m (108 in) and 2.90 m (114 in), with a grid located at about 2.79 m (110 in). 
76 

The bundle was pressurized to 1.38 bar (25 psia) and the reflooding rate was set to 25.4 mm/s 

(1 in/s). The injected water was 339 degrees K (150 degrees F) subcooled. 

The diameter distributions obtained from the two locations can be seen in Figure 3.20. It can be 

seen that the droplet distribution changes shape from upstream to downstream of the grid, and 

that the mean size decreases. As had been done in the FLECHT-SEASET series of tests, the 

data from Figure 3.20 was fitted to a log-normal distribution as shown in Figure 3.21. The figure 

shows the log-normal fit for the distributions upstream and downstream of the grid in the same 

manner as Figure 3.20. The log normal distribution curves show more dramatically the effect of 

spacer grid on droplet breakup. 

The arithmetic mean diameters for the droplets upstream and downstream of the spacer grid 

are 0.64 and 0.45 mm (0.025 and 0.018 in) respectively, which represents a 29 percent 

decrease in the mean size of the droplets. 

A series of separate effects tests were performed on an individual grid strap with individual 

droplets impinging on a thin strip of metal simulating a grid strap. There have also been laserdopler experiments by Lee et al (Ref. 7) and similar experiments by Clare (Ref. 8) to examine 

droplet breakup caused by spacer grids. Figure 3.22 shows a plot of drop breakup data for 

different drop size to grid strap thickness ratios as a function of drop impact Weber number. 

Figure 3.22 also shows the curve fit correlated to the data as a function of the drop diameter to 

strap thickness. 

Figure 3.20 Normalized Droplet Distributions Upstream and 

Downstream of the Spacer Grid. 
77 

Figure 3.21 Probability Distribution Log-Normal Curve Fits Upstream and 

Downstream of the Spacer Grid. 

For the RBHT experiments, the unshattered droplet diameter to grid strap thickness ratio (do/W) 

is 2.1. COBRA-TF computer code calculations were performed for this experiment, and the 

prediction for the velocity of the droplets upstream of the spacer grid is 1.78 m/s (5.85 ft/s). The 

corresponding droplet Weber number (using properties at saturation) is 55.24. Using the 

correlation form given in Figure 3.22 for droplet breakup, the resulting droplet diameter ratio 

(den/do) should be about 0.74. For this RBHT experiment, the ratio is 0.71, using the peak 

values from the distributions shown in Figure 3.21. 
78 

Figure 3.22 Drop Breakup Data as a Function of Droplet Impact Weber Number. 

The change in droplet diameter due to evaporation was another factor considered in the 

FLECHT-SEASET tests. For droplet evaporation over a 76 mm (3 in) length, the droplet 

diameter was calculated to reduce by less than one percent. Therefore, it can be assumed that 

the overall change in droplet diameter due to evaporation would be less than two percent, which 

would not account for much of the 29 percent reduction in diameter over the grid span, as seen 

in Figure 3.21. 

Additional evidence of droplet breakup can be seen in the results from the test matrix. A few 

examples of measurements of mean droplet diameter at different elevations are shown in Figure 

3.23 through Figure 3.25. In these figures, one can clearly see that for tests with identical 

conditions, the droplet diameter decreases with elevation. Figure 3.23 should show the effect of 

a single grid on the droplet diameter. Figure 3.24, likewise shows the effect of a single grid, but 

over a greater length within the bundle. Figure 3.25 represents the effects of two spacer grids 

on the droplet diameter. 
79 

Figure 3.23 Comparison of Droplet Diameter from Experiment 1088 (2.74 m) and 

Experiment 973 (2.86 m). 
80 

Figure 3.24 Comparison of Droplet Diameter from Experiment 1310 (1.84 m) and 

Experiment 1096 (2.36 m). 
81 

Figure 3.25 Comparison of Droplet Diameter from Experiment 1319 (1.84 m) and 

Experiment 1383 (2.86 m). 
82 

3.4.4 Droplet Velocity 

Although the VisiSizer system is capable of obtaining velocity information, its ability to do so in 

the bundle geometry is severely limited. The system uses a double-pulse technique to capture 

a double exposure of the droplet images. The system then compares the location of similar 

droplets to determine the velocity. However, when using the double-pulse mode, contrast in the 

image is much less compared to the single-pulse mode. This makes the droplet recognition 

much harder since the droplets will not be much darker than the background. In addition, 

velocity mode tends to reject more droplets because the diameter rejection criteria are 

compounded by velocity rejection criteria. As a result, the velocity mode captures fewer 

droplets than diameter-only mode. 

However, despite these limitations, some preliminary droplet velocity information was collected 

with the VisiSizer system during one of the early shakedown reflood tests. Figure 3.26 shows a 

plot representing the diameter and velocity distribution for an experiment where the camera was 

located at 2.74 m (108 in) and shows the resulting velocity and size distribution downstream of 

the grid. 

 

Figure 3.26 Size and Velocity Distribution Downstream of the Spacer Grid. 
83 

Figure 3.26 shows that there is very little correlation between droplet size and velocity for 

droplets immediately downstream of a spacer grid. This lack of correlation between drop 

velocity and size has also been observed in the FLECHT-SEASET experiments. 

3.4.5 Calculation of Interfacial Area from Droplet Distribution Data 

In order to estimate the droplet interfacial area in the dispersed flow region of the bundle, the 

digital droplet imaging data is used along with calculations of total liquid flow. In this section, the 

procedure for determining droplet interfacial area will be outlined. 

The dispersed flow film boiling region is extremely complex since the dispersed droplets act as 

heat sinks and alter the vapor superheat temperature such that the film boiling is a two-step 

process. That is, heat is transferred to the continuous vapor phase from the heated walls, and 

then heat is transferred to the entrained water droplets by interfacial heat and mass transfer. As 

a result, the vapor temperature is a dependent parameter that is a function of both the wall heat 

transfer and the interfacial heat transfer. Therefore, the droplet interfacial area is a parameter of 

great importance when investigating these heat transfer processes. 

The droplet data from the digital imaging system can be collected to give a time-line of droplet 

diameter information for a given location within the rod bundle. In addition, the Sauter mean 

diameter (SMD) can also be determined using the conventional formulation.

 

( )

( )

= 2

3

32

i i

i i

f d

f d

d

 (3-44) 

where 

d32 SMD 

fi fraction of droplet group i, 

di diameter of droplet group i 

The SMD represents the diameter of a particle whose ratio of volume to surface area is the 

same as the complete sample. The SMD is calculated over many time intervals in order to 

observe the trend in droplet size. For example, Figure 3.27 shows the SMD evolution for 

Experiment 1383. 

The near flow of droplets is determined from the mass and energy balance program. 

The total interfacial area of the droplets can be estimated from the total droplet volume using the 

calculated mass flow and density and the droplet SMD. 
84 

Figure 3.27 Sauter Mean Diameter Time History for Experiment 1383. 

The volume of n droplets: 

( ) 1 3

6 V n fd = π  i i (3-45) 

where 

diameter of droplet group i

fraction of droplet group i

=

=

i

i

d

f

Surface area of n droplets: 

( ) 2 A n fd = π  i i (3-46)

So, solving of area in terms of volume: 

( )

( ) 32

3

2

6 6

d

V

f d

f d

A V

i i

i i ⋅ = =





 (3-47) 

which represents the simple formula for converting the total measured droplet volume into 

surface area using the SMD measurement. 
85 

Finally, this equation must be converted to a rate equation, since the reported parameter is rate 

of liquid mass. In addition, the mass rate is converted to a volume rate by the liquid density at 

saturation. The resulting rate of interfacial area because: 

32

6

d

m

A

sat

liq

⋅ = ⋅ρ

 

 

(3-48) 

The mass rate for Experiment 1383 is shown in Figure 3.28. Using this formula at several times 

over the reflood transient, a curve representing the evolution of droplet interfacial area can be 

obtained, as shown in Figure 3.29. 

Figure 3.28 Liquid Flow rate for Experiment 1383. 

3.4.6 Droplet Measurement Data for Individual Experiments 

The droplet data and individual number of droplet counts are given in the Appendix A for each 

experiment in which data was obtained. The test run number, camera location, and test 

conditions are given on each plot. The data is taken as a function of time and the moving 

quench front location is also indicated on each plot. Drop mass diameter and Sauter mean 

diameters are also plotted. 
86 

Figure 3.29 Rate of Interfacial Area for Experiment 1383. 

3.5 References

1. Lee, N., Wong, S., Yeh, H.C., and Hochreiter, L.E., “PWR FLECHT-SEASET 

Unblocked Bundle, Forced and Gravity Reflood Task Data Evaluation and Analysis 

Report,” WCAP-9891, February 1982. 

2. Oxford Lasers. “HSI1000 Fast Illumination System,” Operation Manual, Issue 2, Rev. 1 

(1997), Oxford Lasers, Ltd. 

3. Todd, Donald R., “Characterization of the VisiSizer Particle/Drop Sizing System,” MS 

Thesis, Pennsylvania State University, 1999. 

4. Lee, N., et. al., “PWR FLECHT SEASET Unblocked Bundle, Forced and Gravity Reflood 

Task Data Evaluation and Analysis Report,” NUREG/CR-2256, Feb. 1982. 

5. C.Y. Paik, L.E. Hochreiter, J.M. Kelly, R.J. Kohrt “Analysis of FLECHT-SEASET 163-

Rod Blocked Bundle Data Using COBRA-TF”, NUREG/CR-4166, 1985. 

6. Yao, S. C., et al., “Dynamics of Droplets Impacting in Thin Heated Strips,” submitted to 

National Heat Transfer Conference, Denver, 1985. 

7. Lee, Richard S. L., et. al, “A Study of Droplet Hydrodynamics Across a Grid Spacer,” 

NUREG/CR-4034, 1983. 
87 

8. Clare, A. J. and Fairbairn, S. A., “Droplet Dynamics and Heat Transfer in Dispersed 

Two-Phase Flow,” CONF-8410331, 1985. 

9. Rehme, K. “Pressure Drop Correlations for Fuel Element Spacers,” Nuclear Technology, 

Vol. 17, January 1973. 

10. Wantland, J. L., “Compact Tubular Heat Exchangers,” TID 7529, Reactor Heat Transfer 

Conference (Pt. 1), Book 2, 1957. 
88 

4. CONCLUSIONS 

A series of forced reflood heat transfer experiments has been completed in the RBHT Test 

Facility. The reflood heat transfer experiments which were performed provided additional and 

new data which has not been obtained in other rod bundle reflood tests. The new data 

included: 

1. Detailed non-equilibrium vapor superheat temperature measurements along the axial 

length of the bundle, and immediately downstream of the spacer grids. 

2. Spacer grid temperature surface measurements within the rod bundle at the different 

axial positions. 

3. Detailed entrained droplet size measurements as observed between the heater rods 

both upstream and downstream of the spacer grids. 

4. Detailed heater rod temperature measurements along the axial length of the rod bundle 

specifically downstream of the spacer grids. 

5. Detailed pressure drop along the bundle to determine the spacer grid losses and void 

fraction distribution along the bundle length. 

6. Liquid carryover measurements of the entrained liquid flow out of the bundle measured 

using both a small carryover tank and a large carryover tank such that detecting 

entrained water was faster. 

7. Both liquid and steam flows from the bundle exit were measured such that a system 

mass balance could be performed on each test. 

The RBHT reflood heat transfer experiments were specifically designed for use in Best-Estimate 

computer code validation efforts, not as tests to determine licensing limits. As such, these tests 

were designed with more complete instrumentation such that local heat transfer phenomena 

could be identified and quantified more accurately. The experiments were also designed for 

easier computer code modeling with a linear axial power distribution, no radial power gradient, 

and constant power rather than decay power. Using the constant power results in quasi-steady 

reflood tests of much longer duration such that it is easier to model and study the dispersed flow 

film boiling phenomena which is the heat transfer regime of interest. 

The spacer grids used in these experiments are similar in design to prototypical PWR 

production mixing vanes grids found on most PWR fuel assembly designs. The heat transfer 

phenomena associated with the spacers observed in the RBHT Test Facility is expected to be 

similar to that of a commercial PWR. The spacer grids have a first order effect on the local heat 

transfer downstream of the spacer grid. The grids can re-wet, shatter entrained droplets, and 

enhance the convective heat transfer downstream. All these effects enhance the dispersed flow 

film boiling downstream of the grids resulting in lower measured heater rod temperatures 

downstream of the grids. This was clearly observable in the RBHT reflood heat transfer 

experiments. 
89 

The heater rod instrumentation has also been designed such that detailed axial quench front 

information can be obtained for comparisons to Best-Estimate computer codes. The quasisteady nature of the experiments along with the extended reflood times due to the constant 

power which was used, provide a significant challenge to today’s computer code predictions. 

The longer transients will provide an opportunity for errors in the calculations to accumulate and 

cause a deviation from the experimental data. The code developer will have a much clearer 

indication of which models are causing this deviation, since the tests are quasi-steady, such that 

they can more easily correct the problem. The RBHT reflood heat transfer experiments have 

provided new and needed data which can be used for Best-Estimate computer code 

development and validation. 

A-1 

APPENDIX A. TEST RESULTS 

This appendix contains the tables and plots for the selected data of 25 valid reflood heat 

transfer tests performed at the RBHT Test Facility. 

For each test run, the following tables and plots are presented: 

• List of the run conditions 

• Listing of the measurements for the selected thermocouples 

• Upper plenum pressure 

• Inlet liquid flow rate, outlet vapor flow rate 

• Inlet flow temperature 

• Bundle Voltage and Current 

• Rod surface temperatures – calculated as described in Chapter 3, Section 1 at five 

selected locations, corresponding to steam probe locations and at the top section of the 

bundle 

• Steam temperatures - data from 5 steam probes at the upper section of the bundle 

• Grid temperatures for the top 3 spacer grids 

• Heat transfer coefficients - calculated as described in Chapter 3, Section 1 

• Heater rod quench data - calculations performed for this is described in Chapter 3, 

Section 2 

• Droplet Measurements - described in Chapter 3, Section 4 

In temperature, heat transfer coefficient, and quench front plots, time zero represents when the 

reflood starts. 
A-2 

RBHT - REFLOOD TESTS 

SUMMARY SHEET 

RUN NO: 937

RUN CONDITIONS

Upper Plenum Pressure: 138 kPa (20 psia) 

Initial Peak Clad Temperature: 1033 degrees K (1400 degrees F) 

Rod Peak Power: 1.31 kW/m (0.4 kW/ft) 

Flooding Rate: 0.0254 m/s (1 in/s) 

Inlet Subcooling: 11 degrees K (20 degrees F) 

Start of Reflood: 301.3 s 

End of Reflood: 1362 s 

Test Date: 5/13/2002 

Comments: No droplet data 
A-3 

Rod_Elevation Channel Temperature Temperature Turnaround Turnaround Turnaround Quench Quench Quench 

Number at Reflood (K) at Reflood ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F)

B6_0.592m 148 691.42 784.86 15.95 719.63 835.65 90.45 537.15 507.19B6_0.744m 149 712.94 823.61 17.45 743.74 879.05 119.45 555.1 539.49B6_0.846m 150 745.7 882.58 19.45 781.38 946.79 136.95 571.83 569.6B6_0.897m 151 755.42 900.07 18.95 793.09 967.88 147.45 572.53 570.87

C6_1.04m 137 801.34 982.73 24.95 846.15 1063.38 173.45 632.94 679.61D5_1.27m 217 846.11 1063.3 24.95 891.1 1144.3 241.45 587.23 597.32C6_1.34m 138 837.55 1047.9 26.95 890.22 1142.71 262.95 629.08 672.65D5_1.37m 218 870.19 1106.65 30.95 927.33 1209.51 267.45 633.46 680.55C6_1.39m 139 845.35 1061.94 30.95 901.52 1163.05 280.45 621.51 659.02D5_1.45m 219 882.72 1129.21 31.95 942.27 1236.4 292.95 650.26 710.79C6_1.47m 140 861.02 1090.15 33.95 918.6 1193.8 307.95 654.78 718.92D5_1.52m 220 894.33 1150.11 37.45 957.87 1264.48 321.45 694.44 790.31C6_1.62m 141 878 1120.71 99.95 971.96 1289.84 373.45 662.21 732.3D5_1.68m 221 906.65 1172.28 99.95 1010.64 1359.47 388.45 684.78 772.92D5_1.78m 222 896.63 1154.24 25.95 959.63 1267.65 430.45 629.49 673.4D5_1.85m 223 923.24 1202.14 27.95 984.83 1313.01 451.95 682.74 769.25C6_1.87m 142 903.57 1166.75 31.45 968.34 1283.33 473.95 680.62 765.43D5_1.90m 224 931.23 1216.53 31.45 998.06 1336.82 472.45 708.15 814.98C6_1.95m 144 917.29 1191.43 88.95 986.59 1316.18 507.95 656.98 722.87C3_2.17m 178 966.31 1279.67 123.95 1075.68 1476.53 595.45 745.2 881.67D4_2.24m 241 985.83 1314.8 122.95 1094.04 1509.58 652.45 594.39 610.21D4_2.32m 242 991.53 1325.06 22.95 1052.94 1435.6 673.95 613 643.7C3_2.35m 180 988.25 1319.17 22.95 1051.57 1433.14 649.45 669.43 745.29D4_2.37m 243 1000.19 1340.66 23.95 1066.69 1460.36 689.95 623.79 663.14C3_2.40m 181 990.08 1322.46 24.95 1057.6 1444 663.45 671.28 748.62D4_2.54m 245 1022.57 1380.94 25.45 1096.41 1513.86 759.45 658.63 725.85D6_2.62m 129 1015.62 1368.44 98.95 1097.11 1515.11 755.45 679.41 763.25D6_2.69m 130 1009.67 1357.72 110.45 1110.45 1539.13 786.45 685.9 774.93C3_2.76m 183 1009.1 1356.69 114.45 1100.57 1521.33 810.45 694.44 790.3D6_2.87m 131 973.73 1293.03 20.95 1038.54 1409.68 846.45 666.09 739.27D6_2.92m 132 954.9 1259.14 24.45 1025.81 1386.77 860.45 693.4 788.43D6_2.97m 133 934.22 1221.9 25.95 1004.29 1348.04 876.95 708.26 815.18D6_3.07m 134 904.49 1168.39 26.95 973.86 1293.26 897.95 689.48 781.37

E3_3.12m 197 899.34 1159.13 27.95 969.45 1285.32 954.95 647.89 706.52

D6_3.17m 135 868.24 1103.14 27.95 935.34 1223.92 919.95 689.15 780.78D6_3.27m 136 824.13 1023.75 111.45 902.35 1164.54 940.45 671.4 748.83D4_3.61m 248 642.5 696.81 113.45 723.07 841.83 1032.95 544.69 520.76
A-4 
A-5 
A-6 
A-7 

Heater Rod Temperature during Reflood 

RBHT Exp. 937

300

400

500

600

700

800

900

0 100 200 300 400 500 600 700 800 900 1000 1100

Time after Reflood (sec)

Temperature (K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)

Heater Rod Temperature during Reflood 

RBHT Exp. 937

300

400

500

600

700

800

900

1000

0 100 200 300 400 500 600 700 800 900 1000 1100

Time after Reflood (sec)

Temperature (K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)
A-8 

Heater Rod Temperature during Reflood 

RBHT Exp. 937

300

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800 900 1000 1100

Time after Reflood (sec)

Temperature (K)

Chan. 203 2.37m (93.2in)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)

Heater Rod Temperature during Reflood 

RBHT Exp. 937

300

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600 700 800 900 1000 1100

Time after Reflood (sec)

Temperature (K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)
A-9 

Heater Rod Temperature during Reflood 

RBHT Exp. 937

300

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800 900 1000 1100

Time after Reflood (sec)

Temperature (K)

Chan. 195 2.93m (115.4in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.94m (115.7in)

Heater Rod Temperature during Reflood 

RBHT Exp. 937

300

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800 900 1000 1100

Time after Reflood (sec)

Temperature (K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)
A-10 

Heater Rod Temperature during Reflood 

RBHT Exp. 937

300

400

500

600

700

800

900

0 100 200 300 400 500 600 700 800 900 1000 1100

Time after Reflood (sec)

Temperature (K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)

Steam Probe Temperature during Reflood 

RBHT Exp. 937

300

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800 900 1000 1100

Time after Reflood (sec)

Temperature (K)

Chan. 318 2.37m (93.5in)

Chan. 319 2.37m (93.5in)
A-11 

Steam Probe Temperature during Reflood 

RBHT Exp. 937

300

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800 900 1000 1100

Time after Reflood (sec)

Temperature (K)

Chan. 323 2.54m (100in)

Chan. 324 2.54m (100in)

Chan. 325 2.54m (100in)

Steam Probe Temperature during Reflood 

RBHT Exp. 937

300

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800 900 1000 1100

Time after Reflood (sec)

Temperature (K)

Chan. 326 2.93m (115.4in)

Chan. 327 2.93m (115.4in)

Chan. 328 2.93m (115.4in)
A-12 

Steam Probe Temperature during Reflood 

RBHT Exp. 937

300

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800 900 1000 1100

Time after Reflood (sec)

Temperature (K)

Chan. 329 3.05m (120in)

Chan. 330 3.05m (120in)

Chan. 331 3.05m (120in)

Steam Probe Temperature during Reflood 

RBHT Exp. 937

300

400

500

600

700

800

900

0 100 200 300 400 500 600 700 800 900 1000 1100

Time after Reflood (sec)

Temperature (K)

Chan. 332 3.45m (136in)

Chan. 333 3.45m (136in)

Chan. 334 3.45m (136in)
A-13 

Spacer Grid Temperature during Reflood 

RBHT Exp. 937

300

400

500

600

700

800

900

1000

0 100 200 300 400 500 600 700 800 900 1000 1100

Time after Reflood (sec)

Temperature (K)

Chan. 260 1.75m (69in)

Chan. 261 1.75m (69in)

Spacer Grid Temperature during Reflood 

RBHT Exp. 937

300

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800 900 1000 1100

Time after Reflood (sec)

Temperature (K)

Chan. 266 2.26m (89in)

Chan. 267 2.26m (89in)
A-14 

Spacer Grid Temperature during Reflood 

RBHT Exp. 937

300

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800 900 1000 1100

Time after Reflood (sec)

Temperature (K)

Chan. 272 2.79m (110in)

Chan. 273 2.79m (110in)

Chan. 275 2.79m (110in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 937

10

1000

100000

0 100 200 300 400 500 600 700 800 900 1000 1100

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)
A-15 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 937

10

1000

100000

0 100 200 300 400 500 600 700 800 900 1000 1100

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 937

10

1000

100000

0 100 200 300 400 500 600 700 800 900 1000 1100

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 203 2.37m (93.2in)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)
A-16 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 937

1

100

10000

1000000

0 100 200 300 400 500 600 700 800 900 1000 1100

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 937

1

100

10000

1000000

0 100 200 300 400 500 600 700 800 900 1000 1100

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 195 2.93m (115.5in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.93m (115.7in)
A-17 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 937

1

100

10000

1000000

0 100 200 300 400 500 600 700 800 900 1000 1100

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 937

1

100

10000

1000000

0 100 200 300 400 500 600 700 800 900 1000 1100

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)
A-18 

Quench Data, RBHT Exp. 937

0

0.5

1

1.5

2

2.5

3

3.5

4

0 200 400 600 800 1000 1200

Time after Reflood (sec)

Elevation (m)
A-19 

RBHT - REFLOOD TESTS 

SUMMARY SHEET 

RUN NO: 945

RUN CONDITIONS

Upper Plenum Pressure: 276 kPa (40 psia) 

Initial Peak Clad Temperature: 1033 degrees K (1400 degrees F) 

Rod Peak Power: 1.31 kW/m (0.4 kW/ft) 

Flooding Rate: 0.0254 m/s (1 in/s) 

Inlet Subcooling: 11 degrees K (20 degrees F) 

Start of Reflood: 1709 s 

End of Reflood: 2490 s 

Test Date: 5/13/2002 

Comments: No droplet data 
A-20 

Rod_Elevation Channel Temperature Temperature Turnaround Turnaround Turnaround Quench Quench Quench 

Number at Reflood (K) at Reflood ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F)

B6_0.592m 148 717.94 832.6 15.25 743.62 878.83 66.75 563.72 555B6_0.744m 149 724.52 844.45 18.25 756.61 902.21 85.75 566.12 559.33B6_0.846m 150 756.96 902.84 18.25 791.1 964.3 95.75 574.34 574.12B6_0.897m 151 767.92 922.57 19.25 804.37 988.17 100.75 592.69 607.16

C6_1.04m 137 812.76 1003.29 20.75 853.11 1075.9 113.75 631.68 677.33D5_1.27m 217 853.48 1076.57 19.75 894.62 1150.62 148.25 588.89 600.31C6_1.34m 138 851 1072.12 24.75 897.54 1155.88 153.75 632.47 678.76D5_1.37m 218 879.26 1122.98 25.75 928.45 1211.53 160.25 634.23 681.92C6_1.39m 139 860.84 1089.83 25.75 909.84 1178.02 161.25 659.71 727.79D5_1.45m 219 894.5 1150.41 25.75 946.32 1243.68 172.25 665.88 738.9C6_1.47m 140 878.49 1121.6 25.75 928.96 1212.44 174.25 679.15 762.78D5_1.52m 220 910.81 1179.77 26.25 963.5 1274.61 186.25 683.93 771.38C6_1.62m 141 899.84 1160.03 34.75 957.76 1264.28 205.25 695.82 792.79D5_1.68m 221 927.29 1209.44 67.25 989.8 1321.95 218.25 709.37 817.19D5_1.78m 222 909.82 1177.99 23.25 965.46 1278.14 239.75 631.4 676.83D5_1.85m 223 940.35 1232.94 23.25 993.81 1329.17 251.25 676.5 758.02C6_1.87m 142 925.47 1206.16 24.75 981.61 1307.21 256.75 694.67 790.72D5_1.90m 224 948.94 1248.4 25.25 1006.54 1352.08 216.75 793.41 968.44C6_1.95m 144 940.79 1233.74 34.75 998.2 1337.07 275.25 692.53 786.86C3_2.17m 178 987.06 1317.01 71.75 1057.9 1444.54 326.25 756.46 901.95D4_2.24m 241 1003.69 1346.95 87.25 1077.15 1479.19 358.75 706.25 811.57D4_2.32m 242 1007.72 1354.21 20.75 1066.39 1459.82 374.25 630.48 675.17C3_2.35m 180 1008.88 1356.3 20.75 1068.59 1463.77 364.25 683.81 771.17D4_2.37m 243 1019.46 1375.33 21.25 1081.82 1487.59 383.25 675.98 757.07C3_2.40m 181 1011.91 1361.75 21.75 1075.54 1476.28 375.25 716.85 830.64D4_2.54m 245 1029.93 1394.19 23.75 1100.84 1521.82 435.25 703.36 806.36D6_2.62m 129 1017.76 1372.28 75.25 1096.41 1513.85 442.25 743.28 878.22D6_2.69m 130 1002.43 1344.68 89.25 1104.67 1528.73 465.25 769.99 926.3C3_2.76m 183 1003 1345.72 92.25 1105.82 1530.79 489.75 711.31 820.67D6_2.87m 131 934.32 1222.09 21.75 1002.32 1344.49 511.75 661.14 730.37D6_2.92m 132 919.75 1195.86 25.25 992.7 1327.18 519.75 699.19 798.86D6_2.97m 133 899.74 1159.84 26.25 971.57 1289.14 532.75 696.29 793.63D6_3.07m 134 863.4 1094.43 91.75 954.32 1258.09 550.25 698.93 798.39

E3_3.12m 197 853.26 1076.18 221.75 963.04 1273.78 581.25 659.56 727.51

D6_3.17m 135 808.15 994.98 222.25 946.21 1243.48 571.25 701.32 802.69D6_3.27m 136 735.59 864.38 249.25 933.72 1221 591.25 685.63 774.45D4_3.61m 248 562.82 553.39 249.25 750.91 891.94 649.75 567.41 561.65
A-21 
A-22 
A-23 
A-24 

Heater Rod Temperature during Reflood 

RBHT Exp. 945

400

500

600

700

800

900

0 100 200 300 400 500 600 700 800

Time after Reflood (sec)

Temperature (K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)

Heater Rod Temperature during Reflood 

RBHT Exp. 945

400

500

600

700

800

900

1000

0 100 200 300 400 500 600 700 800

Time after Reflood (sec)

Temperature (K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)
A-25 

Heater Rod Temperature during Reflood 

RBHT Exp. 945

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800

Time after Reflood (sec)

Temperature (K)

Chan. 203 2.37m (93.2in)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)

Heater Rod Temperature during Reflood 

RBHT Exp. 945

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600 700 800

Time after Reflood (sec)

Temperature (K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)
A-26 

Heater Rod Temperature during Reflood 

RBHT Exp. 945

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800

Time after Reflood (sec)

Temperature (K)

Chan. 195 2.93m (115.4in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.94m (115.7in)

Heater Rod Temperature during Reflood 

RBHT Exp. 945

400

500

600

700

800

900

1000

0 100 200 300 400 500 600 700 800

Time after Reflood (sec)

Temperature (K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)
A-27 

Heater Rod Temperature during Reflood 

RBHT Exp. 945

400

500

600

700

800

900

0 100 200 300 400 500 600 700 800

Time after Reflood (sec)

Temperature (K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)

Steam Probe Temperature during Reflood 

RBHT Exp. 945

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800

Time after Reflood (sec)

Temperature (K)

Chan. 318 2.37m (93.5in)

Chan. 319 2.37m (93.5in)
A-28 

Steam Probe Temperature during Reflood 

RBHT Exp. 945

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800

Time after Reflood (sec)

Temperature (K)

Chan. 323 2.54m (100in)

Chan. 324 2.54m (100in)

Chan. 325 2.54m (100in)

Steam Probe Temperature during Reflood 

RBHT Exp. 945

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800

Time after Reflood (sec)

Temperature (K)

Chan. 326 2.93m (115.4in)

Chan. 327 2.93m (115.4in)

Chan. 328 2.93m (115.4in)
A-29 

Steam Probe Temperature during Reflood 

RBHT Exp. 945

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800

Time after Reflood (sec)

Temperature (K)

Chan. 329 3.05m (120in)

Chan. 330 3.05m (120in)

Chan. 331 3.05m (120in)

Steam Probe Temperature during Reflood 

RBHT Exp. 945

400

500

600

700

800

900

0 100 200 300 400 500 600 700 800

Time after Reflood (sec)

Temperature (K)

Chan. 332 3.45m (136in)

Chan. 333 3.45m (136in)

Chan. 334 3.45m (136in)
A-30 

Spacer Grid Temperature during Reflood 

RBHT Exp. 945

400

500

600

700

800

900

1000

0 100 200 300 400 500 600 700 800

Time after Reflood (sec)

Temperature (K)

Chan. 260 1.75m (69in)

Chan. 261 1.75m (69in)

Spacer Grid Temperature during Reflood 

RBHT Exp. 945

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800

Time after Reflood (sec)

Temperature (K)

Chan. 266 2.26m (89in)

Chan. 267 2.26m (89in)
A-31 

Spacer Grid Temperature during Reflood 

RBHT Exp. 945

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800

Time after Reflood (sec)

Temperature (K)

Chan. 272 2.79m (110in)

Chan. 273 2.79m (110in)

Chan. 275 2.79m (110in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 945

10

1000

100000

0 100 200 300 400 500 600 700 800

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)
A-32 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 945

10

1000

100000

0 100 200 300 400 500 600 700 800

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 945

10

1000

100000

0 100 200 300 400 500 600 700 800

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 203 2.37m (93.2in)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)
A-33 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 945

1

100

10000

1000000

0 100 200 300 400 500 600 700 800

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 945

1

100

10000

1000000

0 100 200 300 400 500 600 700 800

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 195 2.93m (115.5in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.93m (115.7in)
A-34 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 945

1

100

10000

1000000

0 100 200 300 400 500 600 700 800

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 945

1

100

10000

1000000

0 100 200 300 400 500 600 700 800

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)
A-35 

Quench Data, RBHT Exp. 945

0

0.5

1

1.5

2

2.5

3

3.5

4

0 100 200 300 400 500 600 700 800

Time after Reflood (sec)

Elevation (m)
A-36 

RBHT - REFLOOD TESTS 

SUMMARY SHEET 

RUN NO: 973

RUN CONDITIONS

Upper Plenum Pressure: 276 kPa (40 psia) 

Initial Peak Clad Temperature: 1033 degrees K (1400 degrees F) 

Rod Peak Power: 1.31 kW/m (0.4 kW/ft) 

Flooding Rate: 0.0254 m/s (1 in/s) 

Inlet Subcooling: 11 degrees K (20 degrees F) 

Start of Reflood: 400 s 

End of Reflood: 1233.5 s 

Test Date: 5/16/2002 

Comments: Steam probes positioned in subchannel gaps. 
A-37 

Rod_Elevation Channel Temperature Temperature Turnaround Turnaround Turnaround Quench Quench Quench 

Number at Reflood (K) at Reflood ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F)

B6_0.592m 148 561.51 551.03 17.25 596.77 614.5 45.25 521.81 479.57B6_0.744m 149 552.35 534.54 19.25 592.89 607.51 58.25 526.16 487.39B6_0.846m 150 577.92 580.57 21.75 624.89 665.11 64.75 538.58 509.75B6_0.897m 151 583.16 590.01 22.75 633.96 681.44 68.75 541.49 514.99

C6_1.04m 137 598.93 618.38 25.75 659 726.51 72.75 587.23 597.33D5_1.27m 217 722.18 840.23 25.25 770.03 926.37 98.75 586.51 596.03C6_1.34m 138 785.88 954.89 26.75 835.3 1043.85 109.25 631.24 676.54D5_1.37m 218 828.39 1031.41 26.75 876.39 1117.81 112.25 653.03 715.76C6_1.39m 139 820.57 1017.34 26.25 870.65 1107.48 115.75 659 726.52D5_1.45m 219 868.17 1103.01 28.25 920.46 1197.15 127.75 663.61 734.82C6_1.47m 140 853.12 1075.93 28.25 907.37 1173.57 130.25 682.8 769.35D5_1.52m 220 891.07 1144.24 28.25 949.26 1248.98 144.75 684.8 772.95C6_1.62m 141 878.98 1122.48 29.75 943.81 1239.17 166.25 689.69 781.76D5_1.68m 221 905.62 1170.43 64.75 978.98 1302.48 180.75 714.8 826.94D5_1.78m 222 886.68 1136.33 29.75 961.69 1271.36 205.25 636.5 686.01D5_1.85m 223 915.61 1188.42 30.25 989.89 1322.11 216.75 683.87 771.28C6_1.87m 142 897.71 1156.19 31.25 973.68 1292.93 222.75 681.67 767.32D5_1.90m 224 928.05 1210.8 31.25 1005.69 1350.56 228.75 697.5 795.82C6_1.95m 144 912.44 1182.71 30.75 990.06 1322.41 244.75 691.17 784.42C3_2.17m 178 952.19 1254.25 66.25 1064.58 1456.55 311.75 711 820.11D4_2.24m 241 961.5 1271.01 66.75 1079.04 1482.58 344.75 692.6 787D4_2.32m 242 965.08 1277.46 29.75 1051.13 1432.34 361.75 638.64 689.87C3_2.35m 180 964.61 1276.61 29.75 1050.74 1431.65 354.25 687.53 777.86D4_2.37m 243 981.16 1306.39 30.25 1069.51 1465.43 373.25 669.87 746.09C3_2.40m 181 975.87 1296.88 30.25 1063.83 1455.21 366.75 710.44 819.11D4_2.54m 245 1019.26 1374.99 65.75 1118.93 1554.39 431.25 673.53 752.66D6_2.62m 129 1013.77 1365.1 64.75 1121.26 1558.58 442.25 745.34 881.93D6_2.69m 130 1011.89 1361.72 88.75 1130.96 1576.05 469.25 745.47 882.16C3_2.76m 183 1006.37 1351.78 87.75 1138.1 1588.88 494.75 741.98 875.87D4_2.79m 247 988.29 1319.24 29.25 1094.73 1510.83 517.75 657.63 724.05D6_2.87m 131 972.87 1291.48 29.25 1064.15 1455.78 519.25 660.72 729.6D6_2.92m 132 962.73 1273.23 30.75 1056.95 1442.82 529.75 691.88 785.7D6_2.97m 133 948.33 1247.3 30.75 1039.27 1411 545.75 696.62 794.23D6_3.07m 134 925.23 1205.72 66.75 1021.78 1379.52 567.25 686.83 776.6

E3_3.12m 197 917.56 1191.92 66.75 1024.32 1384.09 589.25 665.73 738.62

D6_3.17m 135 895.9 1152.93 89.25 998.36 1337.36 587.25 678.44 761.5D6_3.27m 136 853.43 1076.49 89.25 968.26 1283.19 605.25 673.84 753.23D4_3.61m 248 729.46 853.34 68.75 799.42 979.27 663.25 576.04 577.19
A-38 
A-39 
A-40 
A-41 

Heater Rod Temperature during Reflood 

RBHT Exp. 973

400

500

600

700

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

Temperature (K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)

Heater Rod Temperature during Reflood 

RBHT Exp. 973

400

500

600

700

800

900

1000

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

Temperature (K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)
A-42 

Heater Rod Temperature during Reflood 

RBHT Exp. 973

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

Temperature (K)

Chan. 203 2.37m (93.2in)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)

Heater Rod Temperature during Reflood 

RBHT Exp. 973

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

Temperature (K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)
A-43 

Heater Rod Temperature during Reflood 

RBHT Exp. 973

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

Temperature (K)

Chan. 195 2.93m (115.4in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.94m (115.7in)

Heater Rod Temperature during Reflood 

RBHT Exp. 973

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

Temperature (K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)
A-44 

Heater Rod Temperature during Reflood 

RBHT Exp. 973

400

500

600

700

800

900

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

Temperature (K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)

Steam Probe Temperature during Reflood 

RBHT Exp. 973

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

Temperature (K)

Chan. 318 2.37m (93.5in)

Chan. 319 2.37m (93.5in)
A-45 

Steam Probe Temperature during Reflood 

RBHT Exp. 973

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

Temperature (K)

Chan. 323 2.54m (100in)

Chan. 324 2.54m (100in)

Chan. 325 2.54m (100in)

Steam Probe Temperature during Reflood 

RBHT Exp. 973

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

Temperature (K)

Chan. 326 2.93m (115.4in)

Chan. 327 2.93m (115.4in)

Chan. 328 2.93m (115.4in)
A-46 

Steam Probe Temperature during Reflood 

RBHT Exp. 973

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

Temperature (K)

Chan. 329 3.05m (120in)

Chan. 330 3.05m (120in)

Chan. 331 3.05m (120in)

Steam Probe Temperature during Reflood 

RBHT Exp. 973

400

500

600

700

800

900

1000

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

Temperature (K)

Chan. 332 3.45m (136in)

Chan. 333 3.45m (136in)

Chan. 334 3.45m (136in)
A-47 

Spacer Grid Temperature during Reflood 

RBHT Exp. 973

400

500

600

700

800

900

1000

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

Temperature (K)

Chan. 260 1.75m (69in)

Chan. 261 1.75m (69in)

Spacer Grid Temperature during Reflood 

RBHT Exp. 973

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

Temperature (K)

Chan. 266 2.26m (89in)

Chan. 267 2.26m (89in)
A-48 

Spacer Grid Temperature during Reflood 

RBHT Exp. 973

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

Temperature (K)

Chan. 272 2.79m (110in)

Chan. 273 2.79m (110in)

Chan. 275 2.79m (110in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 973

10

1000

100000

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)
A-49 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 973

10

1000

100000

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 973

10

1000

100000

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)
A-50 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 973

1

100

10000

1000000

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 973

1

100

10000

1000000

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 195 2.93m (115.5in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.93m (115.7in)
A-51 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 973

1

100

10000

1000000

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 973

1

100

10000

1000000

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)
A-52 

Quench Data, RBHT Exp. 973

0

0.5

1

1.5

2

2.5

3

3.5

4

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

Elevation (m)
A-53 
A-54 
A-55 
A-56 

RBHT - REFLOOD TESTS 

SUMMARY SHEET 

RUN NO: 1088

RUN CONDITIONS

Upper Plenum Pressure: 276 kPa (40 psia) 

Initial Peak Clad Temperature: 1033 degree K (1400 degree F) 

Rod Peak Power: 1.31 kW/m (0.4 kW/ft) 

Flooding Rate: 0.0254 m/s (1 in/s) 

Inlet Subcooling: 11 degree K (20 degree F) 

Start of Reflood: 162.5 s 

End of Reflood: 368.5 s 

Test Date: 5/31/2002 

Comments: Test terminated early but valid to end time. Quench front 

at 1.52 m (60 in) at test termination. 
A-57 

Rod_Elevation Channel Temperature Temperature Turnaround Turnaround Turnaround Quench Quench Quench 

Number at Reflood (K) at Reflood ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F)

B6_0.592m 148 751.13 892.34 13.75 772.87 931.47 63.75 555.39 540.01B6_0.744m 149 768.61 923.82 15.25 794.34 970.12 80.75 577.85 580.44B6_0.846m 150 807.29 993.44 15.75 834.38 1042.19 90.25 586.21 595.49B6_0.897m 151 822.52 1020.85 15.75 850.37 1070.98 95.25 604.54 628.48

C6_1.04m 137 881.53 1127.06 16.75 913.41 1184.46 109.25 651.29 712.63D5_1.27m 217 937.52 1227.85 17.25 970.18 1286.63 149.75 596.42 613.86C6_1.34m 138 926.35 1207.74 18.75 963.45 1274.53 154.75 642.96 697.64D5_1.37m 218 966.17 1279.42 20.75 1004.36 1348.16 162.75 647.25 705.35C6_1.39m 139 938.93 1230.39 19.25 976.51 1298.04 162.75 669.83 746.01D5_1.45m 219 983.86 1311.25 21.25 1023.68 1382.93 175.75 671.6 749.18C6_1.47m 140 958.34 1265.32 19.25 996.35 1333.74 177.75 682.17 768.23D5_1.52m 220 1000.53 1341.27 21.25 1042.25 1416.36 191.75 691.03 784.17
A-58 
A-59 
A-60 
A-61 

Heater Rod Temperature during Reflood 

RBHT Exp. 1088

400

500

600

700

800

900

0 20 40 60 80 100 120 140 160 180 200

Time after Reflood (sec)

Temperature (K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1088

400

500

600

700

800

900

1000

0 50 100 150 200

Time after Reflood (sec)

Temperature (K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)
A-62 

Heater Rod Temperature during Reflood 

RBHT Exp. 1088

400

500

600

700

800

900

1000

1100

1200

0 20 40 60 80 100 120 140 160 180 200

Time after Reflood (sec)

Temperature (K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1088

400

500

600

700

800

900

1000

1100

1200

0 20 40 60 80 100 120 140 160 180 200

Time after Reflood (sec)

Temperature (K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)
A-63 

Heater Rod Temperature during Reflood 

RBHT Exp. 1088

400

500

600

700

800

900

1000

1100

1200

0 20 40 60 80 100 120 140 160 180 200

Time after Reflood (sec)

Temperature (K)

Chan. 195 2.93m (115.4in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.94m (115.7in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1088

400

500

600

700

800

900

1000

1100

0 20 40 60 80 100 120 140 160 180 200

Time after Reflood (sec)

Temperature (K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)
A-64 

Heater Rod Temperature during Reflood 

RBHT Exp. 1088

400

500

600

700

800

900

0 20 40 60 80 100 120 140 160 180 200

Time after Reflood (sec)

Temperature (K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1088

400

500

600

700

800

900

1000

1100

1200

0 20 40 60 80 100 120 140 160 180 200

Time after Reflood (sec)

Temperature (K)

Chan. 318 2.37m (93.5in)

Chan. 319 2.37m (93.5in)
A-65 

Steam Probe Temperature during Reflood 

RBHT Exp. 1088

400

500

600

700

800

900

1000

1100

1200

0 20 40 60 80 100 120 140 160 180 200

Time after Reflood (sec)

Temperature (K)

Chan. 323 2.54m (100in)

Chan. 324 2.54m (100in)

Chan. 325 2.54m (100in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1088

400

500

600

700

800

900

1000

1100

1200

0 20 40 60 80 100 120 140 160 180 200

Time after Reflood (sec)

Temperature (K)

Chan. 326 2.93m (115.4in)

Chan. 327 2.93m (115.4in)

Chan. 328 2.93m (115.4in)
A-66 

Steam Probe Temperature during Reflood 

RBHT Exp. 1088

400

500

600

700

800

900

1000

1100

1200

0 20 40 60 80 100 120 140 160 180 200

Time after Reflood (sec)

Temperature (K)

Chan. 329 3.05m (120in)

Chan. 330 3.05m (120in)

Chan. 331 3.05m (120in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1088

400

500

600

700

800

900

1000

0 20 40 60 80 100 120 140 160 180 200

Time after Reflood (sec)

Temperature (K)

Chan. 332 3.45m (136in)

Chan. 333 3.45m (136in)

Chan. 334 3.45m (136in)
A-67 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1088

400

500

600

700

800

900

1000

1100

0 20 40 60 80 100 120 140 160 180 200

Time after Reflood (sec)

Temperature (K)

Chan. 260 1.75m (69in)

Chan. 261 1.75m (69in)

Spacer Grid Temperature during Reflood 

RBHT Exp. 1088

400

500

600

700

800

900

1000

1100

1200

0 20 40 60 80 100 120 140 160 180 200

Time after Reflood (sec)

Temperature (K)

Chan. 266 2.26m (89in)

Chan. 267 2.26m (89in)
A-68 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1088

400

500

600

700

800

900

1000

1100

1200

0 20 40 60 80 100 120 140 160 180 200

Time after Reflood (sec)

Temperature (K)

Chan. 272 2.79m (110in)

Chan. 273 2.79m (110in)

Chan. 275 2.79m (110in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1088

10

1000

100000

0 20 40 60 80 100 120 140 160 180 200

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)
A-69 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1088

10

1000

100000

0 20 40 60 80 100 120 140 160 180 200

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1088

10

1000

100000

0 20 40 60 80 100 120 140 160 180 200

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)
A-70 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1088

1

100

10000

1000000

0 20 40 60 80 100 120 140 160 180 200

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1088

1

100

10000

1000000

0 20 40 60 80 100 120 140 160 180 200

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 195 2.93m (115.5in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.93m (115.7in)
A-71 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1088

1

100

10000

1000000

0 20 40 60 80 100 120 140 160 180 200

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1088

1

100

10000

1000000

0 20 40 60 80 100 120 140 160 180 200

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)
A-72 

Quench Data, RBHT Exp. 1088

0

0.5

1

1.5

2

2.5

3

3.5

4

0 50 100 150 200

Time after Reflood (sec)

Elevation (m)
A-73 
A-74 
A-75 
A-76 

RBHT - REFLOOD TESTS 

SUMMARY SHEET 

RUN NO: 1096

RUN CONDITIONS

Upper Plenum Pressure: 138 kPa (20 psia) 

Initial Peak Clad Temperature: 1033 degrees K (1400 degrees F) 

Rod Peak Power: 1.31 kW/m (0.4 kW/ft) 

Flooding Rate: 0.0254 m/s (1 in/s) 

Inlet Subcooling: 11 degrees K (20 degrees F) 

Start of Reflood: 227.4 s 

End of Reflood: 1916 s 

Test Date: 6/4/2002 

Comments: 
A-77 

Rod_Elevation Channel Temperature Temperature Turnaround Turnaround Turnaround Quench Quench Quench 

Number at Reflood (K) at Reflood ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F)

B6_0.592m 148 753.98 897.48 11.85 774.04 933.59 96.85 550.57 531.34B6_0.744m 149 761.08 910.26 13.35 783.89 951.31 131.85 548.92 528.37B6_0.846m 150 792.83 967.41 13.35 818.01 1012.74 150.85 583.43 590.48B6_0.897m 151 802.81 985.36 13.35 829.26 1032.98 163.85 600.16 620.6

C6_1.04m 137 853.61 1076.81 18.35 883.6 1130.78 211.35 578.31 581.27D5_1.27m 217 903.05 1165.8 15.35 931.83 1217.61 305.85 590.21 602.7C6_1.34m 138 888.23 1139.12 19.85 924.1 1203.69 332.35 597.62 616.03D5_1.37m 218 926.98 1208.87 25.35 963.94 1275.41 339.35 630.32 674.88C6_1.39m 139 896.74 1154.44 23.85 934.59 1222.57 356.35 634.4 682.23D5_1.45m 219 941.78 1235.51 25.85 980.27 1304.8 372.35 663.47 734.55C6_1.47m 140 914.14 1185.76 24.35 952.65 1255.09 396.85 646.82 704.59D5_1.52m 220 956.17 1261.43 23.35 996.56 1334.13 421.35 587.98 598.68C6_1.62m 141 938.88 1230.3 114.85 1006.36 1351.76 490.85 594.34 610.13D5_1.68m 221 975.73 1296.63 156.85 1058.74 1446.05 513.85 628.68 671.93D5_1.78m 222 968.97 1284.45 17.85 1007.7 1354.18 566.35 628.19 671.06D5_1.85m 223 996.93 1334.79 17.85 1036.66 1406.31 597.85 657.85 724.43C6_1.87m 142 975.55 1296.31 20.35 1018.15 1372.98 621.35 639.12 690.74D5_1.90m 224 1003.67 1346.92 19.85 1046.25 1423.56 626.35 667.91 742.55C6_1.95m 144 983.33 1310.31 114.85 1035.66 1404.5 666.35 602.63 625.04C3_2.17m 178 1028.76 1392.08 232.35 1131.48 1576.98 834.35 578.64 581.87D4_2.24m 241 1049.97 1430.26 239.85 1124.04 1563.59 890.35 567.23 561.32D4_2.32m 242 1060.85 1449.84 15.35 1101.68 1523.34 919.35 630.29 674.84C3_2.35m 180 1054.48 1438.38 15.85 1097.66 1516.09 917.85 607.06 633.02D4_2.37m 243 1068.99 1464.49 15.85 1113.81 1545.16 944.85 548.82 528.19C3_2.40m 181 1056.19 1441.45 16.35 1101.72 1523.41 942.85 572.43 570.69D4_2.54m 245 1091.52 1505.04 16.85 1139.01 1590.53 1040.85 629.2 672.88D6_2.62m 129 1081.44 1486.9 253.85 1137.44 1587.71 1036.85 682.94 769.61D6_2.69m 130 1081.35 1486.74 278.85 1161.24 1630.55 1069.35 716.01 829.13C3_2.76m 183 1079.99 1484.3 559.35 1164.38 1636.2 1151.35 614.69 646.76D4_2.79m 247 1066.75 1460.47 14.85 1116.21 1549.48 1167.85 627.2 669.26D6_2.87m 131 1047.05 1425.01 14.85 1090.37 1502.98 1135.85 662.2 732.28D6_2.92m 132 1026.14 1387.36 16.35 1074.53 1474.47 1157.85 602.44 624.71D6_2.97m 133 998.64 1337.87 16.85 1045.51 1422.23 1184.85 606.02 631.14D6_3.07m 134 962.48 1272.78 17.85 1008.3 1355.26 1215.85 650.79 711.74

E3_3.12m 197 955.16 1259.6 17.35 999.96 1340.24 1303.85 613.15 643.98

D6_3.17m 135 923.17 1202.02 787.35 988.4 1319.43 1244.85 662.89 733.52D6_3.27m 136 879.18 1122.84 788.85 968.77 1284.1 1270.35 636.34 685.73D4_3.61m 248 628.32 671.29 1115.35 740.17 872.62 1400.35 549.81 529.98
A-78 
A-79 
A-80 
A-81 

Heater Rod Temperature during Reflood 

RBHT Exp. 1096

300

400

500

600

700

800

900

0 200 400 600 800 1000 1200 1400 1600 1800

Time after Reflood (sec)

Temperature (K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1096

300

400

500

600

700

800

900

1000

0 200 400 600 800 1000 1200 1400 1600 1800

Time after Reflood (sec)

Temperature (K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)
A-82 

Heater Rod Temperature during Reflood 

RBHT Exp. 1096

300

400

500

600

700

800

900

1000

1100

1200

0 200 400 600 800 1000 1200 1400 1600 1800

Time after Reflood (sec)

Temperature (K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1096

300

400

500

600

700

800

900

1000

1100

1200

0 200 400 600 800 1000 1200 1400 1600 1800

Time after Reflood (sec)

Temperature (K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)
A-83 

Heater Rod Temperature during Reflood 

RBHT Exp. 1096

300

400

500

600

700

800

900

1000

1100

0 200 400 600 800 1000 1200 1400 1600 1800

Time after Reflood (sec)

Temperature (K)

Chan. 195 2.93m (115.4in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.94m (115.7in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1096

300

400

500

600

700

800

900

1000

1100

0 200 400 600 800 1000 1200 1400 1600 1800

Time after Reflood (sec)

Temperature (K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)
A-84 

Heater Rod Temperature during Reflood 

RBHT Exp. 1096

300

400

500

600

700

800

900

0 200 400 600 800 1000 1200 1400 1600 1800

Time after Reflood (sec)

Temperature (K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1096

300

400

500

600

700

800

900

1000

1100

0 200 400 600 800 1000 1200 1400 1600 1800

Time after Reflood (sec)

Temperature (K)

Chan. 318 2.37m (93.5in)

Chan. 319 2.37m (93.5in)
A-85 

Steam Probe Temperature during Reflood 

RBHT Exp. 1096

300

400

500

600

700

800

900

1000

1100

1200

0 200 400 600 800 1000 1200 1400 1600 1800

Time after Reflood (sec)

Temperature (K)

Chan. 323 2.54m (100in)

Chan. 324 2.54m (100in)

Chan. 325 2.54m (100in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1096

300

400

500

600

700

800

900

1000

1100

0 200 400 600 800 1000 1200 1400 1600 1800

Time after Reflood (sec)

Temperature (K)

Chan. 326 2.93m (115.4in)

Chan. 327 2.93m (115.4in)

Chan. 328 2.93m (115.4in)
A-86 

Steam Probe Temperature during Reflood 

RBHT Exp. 1096

300

400

500

600

700

800

900

1000

1100

0 200 400 600 800 1000 1200 1400 1600 1800

Time after Reflood (sec)

Temperature (K)

Chan. 329 3.05m (120in)

Chan. 330 3.05m (120in)

Chan. 331 3.05m (120in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1096

300

400

500

600

700

800

900

0 200 400 600 800 1000 1200 1400 1600 1800

Time after Reflood (sec)

Temperature (K)

Chan. 332 3.45m (136in)

Chan. 333 3.45m (136in)

Chan. 334 3.45m (136in)
A-87 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1096

300

400

500

600

700

800

900

1000

0 200 400 600 800 1000 1200 1400 1600 1800

Time after Reflood (sec)

Temperature (K)

Chan. 260 1.75m (69in)

Chan. 261 1.75m (69in)

Spacer Grid Temperature during Reflood 

RBHT Exp. 1096

300

400

500

600

700

800

900

1000

1100

0 200 400 600 800 1000 1200 1400 1600 1800

Time after Reflood (sec)

Temperature (K)

Chan. 266 2.26m (89in)

Chan. 267 2.26m (89in)
A-88 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1096

300

400

500

600

700

800

900

1000

1100

0 200 400 600 800 1000 1200 1400 1600 1800

Time after Reflood (sec)

Temperature (K)

Chan. 272 2.79m (110in)

Chan. 273 2.79m (110in)

Chan. 275 2.79m (110in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1096

10

1000

100000

0 200 400 600 800 1000 1200 1400 1600 1800

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)
A-89 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1096

10

1000

100000

0 200 400 600 800 1000 1200 1400 1600 1800

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1096

10

1000

100000

0 200 400 600 800 1000 1200 1400 1600 1800

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)
A-90 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1096

1

100

10000

1000000

0 200 400 600 800 1000 1200 1400 1600 1800

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1096

1

100

10000

1000000

0 200 400 600 800 1000 1200 1400 1600 1800

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 195 2.93m (115.5in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.93m (115.7in)
A-91 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1096

1

100

10000

1000000

0 200 400 600 800 1000 1200 1400 1600 1800

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1096

1

100

10000

1000000

0 200 400 600 800 1000 1200 1400 1600 1800

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)
A-92 

Quench Data, RBHT Exp. 1096

0

0.5

1

1.5

2

2.5

3

3.5

4

0 200 400 600 800 1000 1200 1400 1600

Time after Reflood (sec)

Elevation (m)
A-93 
A-94 
A-95 
A-96 

RBHT - REFLOOD TESTS 

SUMMARY SHEET 

RUN NO: 1108

RUN CONDITIONS

Upper Plenum Pressure: 138 kPa (20 psia) 

Initial Peak Clad Temperature: 1033 degrees K (1400 degrees F) 

Rod Peak Power: 1.31 kW/m (0.4 kW/ft) 

Flooding Rate: 0.0254 m/s (1 in/s) 

Inlet Subcooling: 83 degrees K (150 degrees F) 

Start of Reflood: 110.6 s 

End of Reflood: 1492.5 s 

Test Date: 6/6/2002 

Comments: Heater rod surfaces below 1m (40 in) quench to a 

temperature below saturation due to the high inlet 

subcooling. Therefore DATARH calculated heat transfer 

coefficients are not presented below this elevation after rod 

quench. 
A-97 

Rod_Elevation Channel Temperature Temperature Turnaround Turnaround Turnaround Quench Quench Quench 

Number at Reflood (K) at Reflood ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F)

B6_0.592m 148 671.94 749.81 13.65 693.9 789.33 62.15 540.91 513.95B6_0.744m 149 727.95 850.63 14.15 753.24 896.14 85.15 564.9 557.14B6_0.846m 150 767.19 921.26 14.65 796.23 973.52 99.65 554.74 538.85B6_0.897m 151 780.63 945.45 15.15 811.14 1000.37 107.15 570.61 567.41

C6_1.04m 137 835.11 1043.52 18.65 871.06 1108.22 130.65 593.02 607.75D5_1.27m 217 891.98 1145.87 18.65 926.77 1208.51 179.65 578.99 582.49C6_1.34m 138 871.59 1109.18 25.15 914.35 1186.15 189.15 583.27 590.2D5_1.37m 218 910.36 1178.96 32.15 956.44 1261.9 195.15 597.42 615.66C6_1.39m 139 878.72 1122.02 36.15 924.66 1204.7 198.15 608.41 635.44D5_1.45m 219 923 1201.71 39.15 973.09 1291.87 207.65 613.82 645.19C6_1.47m 140 892.45 1146.73 47.15 945.57 1242.34 214.15 613.7 644.97D5_1.52m 220 934.42 1222.27 64.65 993.63 1328.85 225.15 641.34 694.73C6_1.62m 141 910.6 1179.4 84.15 996 1333.12 252.15 650.24 710.74D5_1.68m 221 949.28 1249.01 84.65 1042.15 1416.18 268.15 668.3 743.25D5_1.78m 222 949.45 1249.32 21.15 995.73 1332.63 304.15 607.13 633.15D5_1.85m 223 967.12 1281.13 76.65 1031.59 1397.18 321.65 648.92 708.38C6_1.87m 142 940.75 1233.66 68.15 1016.32 1369.68 331.65 599.88 620.1D5_1.90m 224 971.2 1288.47 84.65 1055.29 1439.83 336.65 677.53 759.87C6_1.95m 144 943.5 1238.61 85.15 1039.94 1412.2 361.15 660.88 729.89C3_2.17m 178 974.69 1294.76 193.65 1133.26 1580.17 479.65 644.55 700.51D4_2.24m 241 996.67 1334.31 193.65 1151.47 1612.96 548.15 588.41 599.44D4_2.32m 242 1005 1349.31 237.65 1091.04 1504.19 581.15 657.26 723.39C3_2.35m 180 992.68 1327.14 242.65 1084.37 1492.17 571.15 679.11 762.72D4_2.37m 243 1010.34 1358.92 237.15 1102.69 1525.16 607.15 610.5 639.21C3_2.40m 181 995.53 1332.26 243.15 1095.46 1512.13 607.65 665.28 737.82D4_2.54m 245 1041.68 1415.33 250.15 1179.95 1664.22 736.65 602.38 624.59D6_2.62m 129 1023.82 1383.18 280.15 1191.99 1685.89 779.65 642.4 696.64D6_2.69m 130 1026.91 1388.75 302.15 1221.09 1738.27 828.15 606.71 632.38C3_2.76m 183 1033.75 1401.06 360.15 1247.6 1785.99 859.15 677.13 759.14D4_2.79m 247 1025.14 1385.56 393.65 1170.46 1647.15 898.15 636.34 685.73D6_2.87m 131 997.01 1334.93 18.15 1053.29 1436.24 919.65 674.61 754.6D6_2.92m 132 978.16 1300.99 432.65 1059.65 1447.68 945.65 649.69 709.76D6_2.97m 133 953.97 1257.46 470.65 1067.94 1462.61 974.65 660.17 728.61D6_3.07m 134 922.38 1200.6 516.15 1073.28 1472.22 1015.15 523.32 482.29

E3_3.12m 197 918.23 1193.13 516.15 1097.16 1515.19 1047.65 586.33 595.71

D6_3.17m 135 887.54 1137.88 556.15 1077.2 1479.28 1051.65 656.53 722.07D6_3.27m 136 847.77 1066.3 554.65 1065.37 1457.98 1091.65 538.8 510.16D4_3.61m 248 614.3 646.06 697.65 807.28 993.42 1201.15 564.7 556.76
A-98 
A-99 
A-100 
A-101 

Heater Rod Temperature during Reflood 

RBHT Exp. 1108

300

400

500

600

700

800

900

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

Temperature (K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1108

300

400

500

600

700

800

900

1000

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

Temperature (K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)
A-102 

Heater Rod Temperature during Reflood 

RBHT Exp. 1108

300

400

500

600

700

800

900

1000

1100

1200

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

Temperature (K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1108

300

400

500

600

700

800

900

1000

1100

1200

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

Temperature (K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)
A-103 

Heater Rod Temperature during Reflood 

RBHT Exp. 1108

300

400

500

600

700

800

900

1000

1100

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

Temperature (K)

Chan. 195 2.93m (115.4in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.94m (115.7in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1108

300

400

500

600

700

800

900

1000

1100

1200

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

Temperature (K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)
A-104 

Heater Rod Temperature during Reflood 

RBHT Exp. 1108

300

400

500

600

700

800

900

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

Temperature (K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1108

300

400

500

600

700

800

900

1000

1100

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

Temperature (K)

Chan. 318 2.37m (93.5in)

Chan. 319 2.37m (93.5in)
A-105 

Steam Probe Temperature during Reflood 

RBHT Exp. 1108

300

400

500

600

700

800

900

1000

1100

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

Temperature (K)

Chan. 323 2.54m (100in)

Chan. 324 2.54m (100in)

Chan. 325 2.54m (100in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1108

300

400

500

600

700

800

900

1000

1100

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

Temperature (K)

Chan. 326 2.93m (115.4in)

Chan. 327 2.93m (115.4in)

Chan. 328 2.93m (115.4in)
A-106 

Steam Probe Temperature during Reflood 

RBHT Exp. 1108

300

400

500

600

700

800

900

1000

1100

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

Temperature (K)

Chan. 329 3.05m (120in)

Chan. 330 3.05m (120in)

Chan. 331 3.05m (120in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1108

300

400

500

600

700

800

900

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

Temperature (K)

Chan. 332 3.45m (136in)

Chan. 333 3.45m (136in)

Chan. 334 3.45m (136in)
A-107 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1108

300

400

500

600

700

800

900

1000

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

Temperature (K)

Chan. 260 1.75m (69in)

Chan. 261 1.75m (69in)

Spacer Grid Temperature during Reflood 

RBHT Exp. 1108

300

400

500

600

700

800

900

1000

1100

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

Temperature (K)

Chan. 266 2.26m (89in)

Chan. 267 2.26m (89in)
A-108 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1108

300

400

500

600

700

800

900

1000

1100

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

Temperature (K)

Chan. 272 2.79m (110in)

Chan. 273 2.79m (110in)

Chan. 275 2.79m (110in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1108

10

1000

100000

10000000

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)
A-109 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1108

10

1000

100000

10000000

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1108

10

1000

100000

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)
A-110 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1108

1

100

10000

1000000

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1108

1

100

10000

1000000

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 195 2.93m (115.5in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.93m (115.7in)
A-111 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1108

1

100

10000

1000000

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1108

1

100

10000

1000000

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)
A-112 

Quench Data, RBHT Exp. 1108

0

0.5

1

1.5

2

2.5

3

3.5

4

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

Elevation (m)
A-113 
A-114 
A-115 
A-116 

RBHT - REFLOOD TESTS 

SUMMARY SHEET 

RUN NO: 1143

RUN CONDITIONS

Upper Plenum Pressure: 138 kPa (20 psia) 

Initial Peak Clad Temperature: 1144 degrees K (1600 degrees F) 

Rod Peak Power: 2.3 kW/m (0.7 kW/ft) 

Flooding Rate: 0.1524 m/s (6 in/s) 

Inlet Subcooling: 83 degrees K (150 degrees F) 

Start of Reflood: 740.3 s 

End of Reflood: 1022.5 s 

Test Date: 6/12/2002 

Comments: Heater rod surfaces below 2.4 m (94 in) quench to a 

temperature below saturation due to the high inlet 

subcooling. Therefore DATARH calculated heat transfer 

coefficients are not presented below this elevation after rod 

quench. 
A-117 

Rod_Elevation Channel Temperature Temperature Turnaround Turnaround Turnaround Quench Quench Quench 

Number at Reflood (K) at Reflood ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F)

B2_0.592m 52 799.73 979.82 10.95 832.22 1038.31 25.45 712.51 822.83B2_0.744m 53 820.34 1016.92 12.45 857.19 1083.26 30.95 731.69 857.36B6_0.846m 150 857.57 1083.95 12.45 896.44 1153.9 34.95 730.24 854.74B6_0.897m 151 867.31 1101.46 13.45 908.74 1176.04 35.45 753.48 896.57

C6_1.04m 137 918.32 1193.28 13.95 964.95 1277.22 42.45 761.75 911.47D5_1.27m 217 984.05 1311.59 12.95 1028.55 1391.71 52.95 729.5 853.41C6_1.34m 138 971.69 1289.35 13.95 1024.8 1384.95 56.45 709.92 818.17D5_1.37m 218 1004.43 1348.29 13.95 1057.46 1443.74 58.45 762.57 912.94C6_1.39m 139 975.97 1297.06 13.95 1030.64 1395.47 59.95 744.58 880.56D5_1.45m 219 1015.62 1368.43 13.95 1070.59 1467.37 62.45 753.64 896.86C6_1.47m 140 989.19 1320.85 14.45 1044.76 1420.88 63.95 740.6 873.39D5_1.52m 220 1026.91 1388.75 14.45 1083.9 1491.34 67.45 752.16 894.19C6_1.62m 141 1010.26 1358.79 14.95 1070.36 1466.97 72.45 761.29 910.63D5_1.68m 221 1046.07 1423.24 14.45 1106.74 1532.45 75.95 773.42 932.46D5_1.78m 222 1031.35 1396.74 12.95 1085.48 1494.17 82.45 697.27 795.4D5_1.85m 223 1064.15 1455.78 12.95 1123.29 1562.24 86.45 692.35 786.55C6_1.87m 142 1044.95 1421.23 13.45 1106.65 1532.28 86.95 734.69 862.76D5_1.90m 224 1068.32 1463.28 13.45 1130.4 1575.03 87.95 696.34 793.73C6_1.95m 144 1047.84 1426.43 13.45 1111.1 1540.29 92.45 694.79 790.94C3_2.17m 178 1079.69 1483.76 13.95 1148.87 1608.28 111.95 701.87 803.69D4_2.24m 241 1087.85 1498.44 13.95 1157.35 1623.55 116.95 690.72 783.6D4_2.32m 242 1107.94 1534.61 12.45 1170.43 1647.09 121.45 664.57 736.53C3_2.35m 180 1103.05 1525.8 12.95 1169.43 1645.28 123.95 671.55 749.1D4_2.37m 243 1114.69 1546.75 12.45 1181.75 1667.46 125.45 673.81 753.16C3_2.40m 181 1104.03 1527.57 12.95 1172.51 1650.83 128.45 684.85 773.05D4_2.54m 245 1146.16 1603.41 12.45 1214.37 1726.17 141.45 692.98 787.68D6_2.62m 129 1144.39 1600.22 12.45 1213.76 1725.08 149.95 701.59 803.18D6_2.69m 130 1146.37 1603.78 12.45 1218.42 1733.46 159.95 697.69 796.15C3_2.76m 183 1145.26 1601.78 12.95 1216.2 1729.48 171.45 674.24 753.95D4_2.79m 247 1103.13 1525.95 11.95 1172.92 1651.58 175.45 666.03 739.16D6_2.87m 131 1093.63 1508.85 11.45 1156.26 1621.59 184.45 628.59 671.78D6_2.92m 132 1063.9 1455.34 12.95 1133.35 1580.34 192.95 619.47 655.36D6_2.97m 133 1029.37 1393.17 12.95 1094.94 1511.21 201.95 614.83 647D6_3.07m 134 985.81 1314.78 12.95 1046.9 1424.73 214.95 609.23 636.93

E3_3.12m 197 971.84 1289.62 13.45 1030.67 1395.52 223.45 588.84 600.22

D6_3.17m 135 942.25 1236.35 12.95 999.11 1338.71 229.95 597.58 615.95D6_3.27m 136 892.36 1146.56 13.45 945.82 1242.79 217.95 606.41 631.85D4_3.61m 248 650.11 710.51 14.45 700.83 801.81 39.95 498.91 438.34
A-118 
A-119 
A-120 
A-121 

Heater Rod Temperature during Reflood 

RBHT Exp. 1143

300

400

500

600

700

800

900

1000

0 50 100 150 200 250 300

Time after Reflood (sec)

Temperature (K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1143

300

400

500

600

700

800

900

1000

1100

0 50 100 150 200 250 300

Time after Reflood (sec)

Temperature (K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)
A-122 

Heater Rod Temperature during Reflood 

RBHT Exp. 1143

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300

Time after Reflood (sec)

Temperature (K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1143

300

400

500

600

700

800

900

1000

1100

1200

1300

0 50 100 150 200 250 300

Time after Reflood (sec)

Temperature (K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)
A-123 

Heater Rod Temperature during Reflood 

RBHT Exp. 1143

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300

Time after Reflood (sec)

Temperature (K)

Chan. 195 2.93m (115.4in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.94m (115.7in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1143

300

400

500

600

700

800

900

1000

1100

0 50 100 150 200 250 300

Time after Reflood (sec)

Temperature (K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)
A-124 

Heater Rod Temperature during Reflood 

RBHT Exp. 1143

300

400

500

600

700

800

900

0 50 100 150 200 250 300

Time after Reflood (sec)

Temperature (K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1143

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300

Time after Reflood (sec)

Temperature (K)

Chan. 318 2.37m (93.5in)

Chan. 319 2.37m (93.5in)
A-125 

Steam Probe Temperature during Reflood 

RBHT Exp. 1143

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300

Time after Reflood (sec)

Temperature (K)

Chan. 323 2.54m (100in)

Chan. 324 2.54m (100in)

Chan. 325 2.54m (100in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1143

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300

Time after Reflood (sec)

Temperature (K)

Chan. 326 2.93m (115.4in)

Chan. 327 2.93m (115.4in)

Chan. 328 2.93m (115.4in)
A-126 

Steam Probe Temperature during Reflood 

RBHT Exp. 1143

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300

Time after Reflood (sec)

Temperature (K)

Chan. 329 3.05m (120in)

Chan. 330 3.05m (120in)

Chan. 331 3.05m (120in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1143

300

400

500

600

700

800

900

1000

0 50 100 150 200 250 300

Time after Reflood (sec)

Temperature (K)

Chan. 332 3.45m (136in)

Chan. 333 3.45m (136in)

Chan. 334 3.45m (136in)
A-127 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1143

300

400

500

600

700

800

900

1000

1100

0 50 100 150 200 250 300

Time after Reflood (sec)

Temperature (K)

Chan. 260 1.75m (69in)

Chan. 261 1.75m (69in)

Spacer Grid Temperature during Reflood 

RBHT Exp. 1143

300

400

500

600

700

800

900

1000

1100

0 50 100 150 200 250 300

Time after Reflood (sec)

Temperature (K)

Chan. 266 2.26m (89in)

Chan. 267 2.26m (89in)
A-128 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1143

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300

Time after Reflood (sec)

Temperature (K)

Chan. 272 2.79m (110in)

Chan. 273 2.79m (110in)

Chan. 275 2.79m (110in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1143

1

1000

1000000

0 50 100 150 200 250 300

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)
A-129 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1143

1

1000

1000000

0 50 100 150 200 250 300

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1143

1

1000

1000000

0 50 100 150 200 250 300

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)
A-130 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1143

1

100

10000

1000000

0 50 100 150 200 250 300

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1143

1

100

10000

1000000

0 50 100 150 200 250 300

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 195 2.93m (115.5in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.93m (115.7in)
A-131 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1143

1

100

10000

1000000

0 50 100 150 200 250 300

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1143

1

100

10000

1000000

0 50 100 150 200 250 300

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)
A-132 

Quench Data, RBHT Exp. 1143

0

0.5

1

1.5

2

2.5

3

3.5

4

0 50 100 150 200 250 300

Time after Reflood (sec)

Elevation (m)
A-133 
A-134 
A-135 
A-136 

RBHT - REFLOOD TESTS 

SUMMARY SHEET 

RUN NO: 1155

RUN CONDITIONS

Upper Plenum Pressure: 138 kPa (20 psia) 

Initial Peak Clad Temperature: 1144 degrees K (1600 degrees F) 

Rod Peak Power: 2.3 kW/m (0.7 kW/ft) 

Flooding Rate: 0.1524 m/s (6 in/s) 

Inlet Subcooling: 11 degrees K (20 degrees F) 

Start of Reflood: 369 s 

End of Reflood: 774 s 

Test Date: 6/14/2002 

Comments: Test terminated early, valid up to end of reflood time. 

Quench front at 2.35 m (93 in) at test termination. 

 No Droplet Data 
A-137 

Rod_Elevation Channel Temperature Temperature Turnaround Turnaround Turnaround Quench Quench Quench 

Number at Reflood (K) at Reflood ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F)

B6_0.592m 148 806.43 991.89 12.25 843.36 1058.35 64.75 579.62 583.63B6_0.744m 149 813.78 1005.12 14.25 854.99 1079.29 88.75 606.24 631.54B6_0.846m 150 845.93 1062.98 14.75 890.89 1143.92 105.75 588.51 599.62B6_0.897m 151 856.54 1082.08 15.25 902.93 1165.59 114.75 596.24 613.54

C6_1.04m 137 909.31 1177.06 15.25 961.27 1270.6 137.75 635.6 684.4D5_1.27m 217 971.45 1288.93 13.75 1022.39 1380.62 182.75 633.45 680.52C6_1.34m 138 956.58 1262.15 15.25 1014.03 1365.57 198.25 642.86 697.45D5_1.37m 218 991.85 1325.65 14.75 1049.09 1428.67 200.25 665.21 737.7C6_1.39m 139 961.87 1271.69 15.25 1020.87 1377.87 208.25 656.02 721.15D5_1.45m 219 1003.75 1347.06 15.25 1062.92 1453.57 213.25 679.57 763.54C6_1.47m 140 974.8 1294.94 15.75 1035.1 1403.49 222.75 681.33 766.71D5_1.52m 220 1015.5 1368.2 15.75 1076.8 1478.54 228.75 699.87 800.07C6_1.62m 141 995.04 1331.39 15.75 1059.86 1448.07 256.75 711.62 821.22D5_1.68m 221 1034.01 1401.53 15.75 1099.44 1519.3 263.75 743.77 879.1D5_1.78m 222 1021.54 1379.09 13.75 1080.21 1484.68 286.75 671.16 748.4D5_1.85m 223 1050.77 1431.7 13.75 1114.03 1545.56 299.75 700.09 800.48C6_1.87m 142 1027.47 1389.77 14.25 1093.23 1508.13 313.75 708.58 815.76D5_1.90m 224 1056.79 1442.54 14.25 1122.99 1561.7 309.75 723.29 842.24C6_1.95m 144 1033.55 1400.7 14.25 1101.13 1522.35 331.25 713.83 825.21C3_2.17m 178 1069.76 1465.89 14.75 1143.53 1598.66 364.75 746.55 884.09D4_2.24m 241 1076.16 1477.41 13.75 1145.27 1601.8 389.25 700.77 801.7C3_2.35m 180 1086.68 1496.34 13.75 1158.25 1625.17 394.75 714.36 826.15D4_3.61m 248 667.78 742.31 15.25 726.89 848.72 41.25 503.84 447.23
A-138 
A-139 
A-140 
A-141 

Heater Rod Temperature during Reflood 

RBHT Exp. 1155

300

400

500

600

700

800

900

1000

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

Temperature (K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1155

300

400

500

600

700

800

900

1000

1100

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

Temperature (K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)
A-142 

Heater Rod Temperature during Reflood 

RBHT Exp. 1155

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

Temperature (K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1155

300

400

500

600

700

800

900

1000

1100

1200

1300

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

Temperature (K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)
A-143 

Heater Rod Temperature during Reflood 

RBHT Exp. 1155

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

Temperature (K)

Chan. 195 2.93m (115.4in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.94m (115.7in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1155

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

Temperature (K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)
A-144 

Heater Rod Temperature during Reflood 

RBHT Exp. 1155

300

400

500

600

700

800

900

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

Temperature (K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1155

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

Temperature (K)

Chan. 318 2.37m (93.5in)

Chan. 319 2.37m (93.5in)
A-145 

Steam Probe Temperature during Reflood 

RBHT Exp. 1155

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

Temperature (K)

Chan. 323 2.54m (100in)

Chan. 324 2.54m (100in)

Chan. 325 2.54m (100in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1155

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

Temperature (K)

Chan. 326 2.93m (115.4in)

Chan. 327 2.93m (115.4in)

Chan. 328 2.93m (115.4in)
A-146 

Steam Probe Temperature during Reflood 

RBHT Exp. 1155

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

Temperature (K)

Chan. 329 3.05m (120in)

Chan. 330 3.05m (120in)

Chan. 331 3.05m (120in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1155

300

400

500

600

700

800

900

1000

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

Temperature (K)

Chan. 332 3.45m (136in)

Chan. 333 3.45m (136in)

Chan. 334 3.45m (136in)
A-147 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1155

300

400

500

600

700

800

900

1000

1100

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

Temperature (K)

Chan. 260 1.75m (69in)

Chan. 261 1.75m (69in)

Spacer Grid Temperature during Reflood 

RBHT Exp. 1155

300

400

500

600

700

800

900

1000

1100

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

Temperature (K)

Chan. 266 2.26m (89in)

Chan. 267 2.26m (89in)
A-148 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1155

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

Temperature (K)

Chan. 272 2.79m (110in)

Chan. 273 2.79m (110in)

Chan. 275 2.79m (110in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1155

1

1000

1000000

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)
A-149 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1155

1

1000

1000000

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1155

1

1000

1000000

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)
A-150 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1155

1

100

10000

1000000

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1155

1

100

10000

1000000

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 195 2.93m (115.5in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.93m (115.7in)
A-151 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1155

1

100

10000

1000000

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1155

1

100

10000

1000000

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)
A-152 

Quench Data, RBHT Exp. 1155

0

0.5

1

1.5

2

2.5

3

3.5

4

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

Elevation (m)
A-153 

RBHT - REFLOOD TESTS 

SUMMARY SHEET 

RUN NO: 1160

RUN CONDITIONS

Upper Plenum Pressure: 276 kPa (40 psia) 

Initial Peak Clad Temperature: 1144 degrees K (1600 degrees F) 

Rod Peak Power: 2.3 kW/m (0.7 kW/ft) 

Flooding Rate: 0.127 m/s (5 in/s) 

Inlet Subcooling: 83 degrees K (150 degrees F) 

Start of Reflood: 129.5 s 

End of Reflood: 504.6 s 

Test Date: 6/17/2002 

Comments: Heater rod surfaces below 2.4 m (94 in) quench to a 

temperature below saturation due to the high inlet 

subcooling. Therefore DATARH calculated heat transfer 

coefficients are not presented below this elevation after rod 

quench. 
A-154 

 Rod_Elevation Channel Temperature Temperature Turnaround Turnaround Turnaround Quench Quench Quench Number at Reflood (K) at Reflood ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F) B6_0.592m 148 818.33 1013.31 14.25 860.05 1088.4 34.25 713.04 823.78 B6_0.744m 149 818.69 1013.96 14.25 862.97 1093.65 41.25 697.24 795.35 B6_0.846m 150 852.36 1074.56 15.75 901.64 1163.26 45.25 699.56 799.52 B6_0.897m 151 863.86 1095.26 15.75 914.66 1186.7 47.25 691.87 785.68 C6_1.04m 137 917.12 1191.12 17.25 973.98 1293.48 54.25 724.27 844 D5_1.27m 217 976.23 1297.53 15.75 1033.59 1400.77 64.75 708.29 815.24 C6_1.34m 138 962.16 1272.19 17.25 1026.62 1388.23 67.75 716.06 829.21 D5_1.37m 218 997.21 1335.3 17.25 1061.4 1450.83 71.75 701.91 803.76 C6_1.39m 139 969.31 1285.06 18.75 1034.59 1402.57 72.75 706.48 811.98 D5_1.45m 219 1010.47 1359.15 17.25 1076.87 1478.67 75.75 702.68 805.14 C6_1.47m 140 982.43 1308.68 18.75 1049.05 1428.6 77.25 696.78 794.52 D5_1.52m 220 1022.67 1381.12 18.75 1091.98 1505.87 80.75 718.86 834.26 C6_1.62m 141 1001.92 1343.77 20.75 1074.55 1474.51 84.75 752.91 895.55 D5_1.68m 221 1042.03 1415.96 21.75 1116.85 1550.64 89.75 738 868.71 D5_1.78m 222 1030.49 1395.19 15.75 1096.85 1514.65 97.25 682.93 769.58

D5_1.85m 223 1055.81 1440.76 15.75 1128.03 1570.77 100.75 684.31 772.06C6_1.87m 142 1031.79 1397.53 17.25 1106.62 1532.23 103.75 661.6 731.2D5_1.90m 224 1062.37 1452.58 17.25 1137.41 1587.66 97.75 738.65 869.88C6_1.95m 144 1039.09 1410.68 17.25 1115.78 1548.71 108.25 665.51 738.24C3_2.17m 178 1076.12 1477.32 17.75 1159.88 1628.1 129.75 661.72 731.41D4_2.24m 241 1076.67 1478.32 15.75 1154.72 1618.81 135.75 661.09 730.28D4_2.32m 242 1099.71 1519.79 16.25 1177.92 1660.56 142.25 651.13 712.35C3_2.35m 180 1089.4 1501.23 15.75 1171.83 1649.6 145.25 658.16 725D4_2.37m 243 1105.78 1530.72 15.75 1187.37 1677.58 147.75 645.12 701.53C3_2.40m 181 1092.23 1506.32 15.75 1175.89 1656.92 150.75 666.73 740.43D4_2.54m 245 1144.09 1599.67 15.25 1227.11 1749.11 168.75 677.19 759.26D6_2.62m 129 1136.52 1586.06 15.25 1222.11 1740.11 179.25 690.26 782.78D6_2.69m 130 1138.76 1590.08 15.25 1227.05 1748.99 190.75 703.45 806.51C3_2.76m 183 1139.89 1592.12 16.75 1227.82 1750.38 202.75 706.46 811.95D6_2.87m 131 1088.3 1499.26 14.25 1168.88 1644.29 219.75 669.33 745.11D6_2.92m 132 1063.23 1454.12 16.25 1147.15 1605.18 226.75 667.81 742.37D6_2.97m 133 1034.41 1402.26 16.25 1113.4 1544.44 233.75 668.58 743.76D6_3.07m 134 996.35 1333.74 16.25 1069.86 1466.07 243.25 676.39 757.81

E3_3.12m 197 992.19 1326.25 16.25 1063.15 1453.97 252.25 664.71 736.8

D6_3.17m 135 957.16 1263.19 16.25 1025.58 1386.36 254.75 673.86 753.27D6_3.27m 136 908.66 1175.9 17.75 974.85 1295.03 266.75 662.26 732.38D4_3.61m 248 697.64 796.07 20.25 763.02 913.75 235.25 433.79 321.14
A-155 
A-156 
A-157 
A-158 

Heater Rod Temperature during Reflood 

RBHT Exp. 1160

300

400

500

600

700

800

900

1000

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

Temperature (K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1160

300

400

500

600

700

800

900

1000

1100

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

Temperature (K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)
A-159 

Heater Rod Temperature during Reflood 

RBHT Exp. 1160

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

Temperature (K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1160

400

500

600

700

800

900

1000

1100

1200

1300

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

Temperature (K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)
A-160 

Heater Rod Temperature during Reflood 

RBHT Exp. 1160

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

Temperature (K)

Chan. 195 2.93m (115.4in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.94m (115.7in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1160

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

Temperature (K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)
A-161 

Heater Rod Temperature during Reflood 

RBHT Exp. 1160

400

500

600

700

800

900

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

Temperature (K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1160

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

Temperature (K)

Chan. 318 2.37m (93.5in)

Chan. 319 2.37m (93.5in)
A-162 

Steam Probe Temperature during Reflood 

RBHT Exp. 1160

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

Temperature (K)

Chan. 323 2.54m (100in)

Chan. 324 2.54m (100in)

Chan. 325 2.54m (100in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1160

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

Temperature (K)

Chan. 326 2.93m (115.4in)

Chan. 327 2.93m (115.4in)

Chan. 328 2.93m (115.4in)
A-163 

Steam Probe Temperature during Reflood 

RBHT Exp. 1160

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

Temperature (K)

Chan. 329 3.05m (120in)

Chan. 330 3.05m (120in)

Chan. 331 3.05m (120in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1160

400

500

600

700

800

900

1000

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

Temperature (K)

Chan. 332 3.45m (136in)

Chan. 333 3.45m (136in)

Chan. 334 3.45m (136in)
A-164 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1160

300

400

500

600

700

800

900

1000

1100

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

Temperature (K)

Chan. 260 1.75m (69in)

Chan. 261 1.75m (69in)

Spacer Grid Temperature during Reflood 

RBHT Exp. 1160

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

Temperature (K)

Chan. 266 2.26m (89in)

Chan. 267 2.26m (89in)
A-165 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1160

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

Temperature (K)

Chan. 272 2.79m (110in)

Chan. 273 2.79m (110in)

Chan. 275 2.79m (110in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1160

1

1000

1000000

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)
A-166 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1160

1

1000

1000000

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1160

1

1000

1000000

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)
A-167 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1160

1

100

10000

1000000

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1160

1

100

10000

1000000

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 195 2.93m (115.5in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.93m (115.7in)
A-168 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1160

1

100

10000

1000000

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1160

1

100

10000

1000000

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)
A-169 

Quench Data, RBHT Exp. 1160

0

0.5

1

1.5

2

2.5

3

3.5

4

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

Elevation (m)
A-170 
A-171 
A-172 
A-173 

RBHT - REFLOOD TESTS 

SUMMARY SHEET 

RUN NO: 1170

RUN CONDITIONS

Upper Plenum Pressure: 276 kPa (40 psia) 

Initial Peak Clad Temperature: 1144 degrees K (1600 degrees F) 

Rod Peak Power: 2.3 kW/m (0.7 kW/ft) 

Flooding Rate: 0.1524 m/s (6 in/s) 

Inlet Subcooling: 11 degrees K (20 degrees F) 

Start of Reflood: 298 s 

End of Reflood: 771.8 s 

Test Date: 6/19/2002 

Comments: No droplet data 

 A heater rod surface (chan. 200) at 3.45 m (135.6 in) 

quenches to a temperature below saturation due to bottom 

reflood from subcooled liquid accumulation in the upper 

plenum. Therefore DATARH calculated heat transfer 

coefficients are not presented for this channel. 
A-174 

Rod_Elevation Channel Temperature Temperature Turnaround Turnaround Turnaround Quench Quench Quench 

Number at Reflood (K) at Reflood ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F)

B6_0.592m 148 825.48 1026.17 8.75 851.96 1073.84 58.75 607.5 633.81B6_0.744m 149 832.44 1038.7 10.25 864.3 1096.05 75.75 629.52 673.46B6_0.846m 150 862.56 1092.92 10.25 896.68 1154.34 86.25 606.51 632.02B6_0.897m 151 874.8 1114.95 10.75 910.37 1178.97 90.75 622.74 661.24

C6_1.04m 137 930.88 1215.89 11.25 970.1 1286.49 101.75 662.74 733.24D5_1.27m 217 986.05 1315.2 11.75 1027.54 1389.88 126.75 631.07 676.24C6_1.34m 138 975.74 1296.65 12.25 1021.93 1379.79 133.75 647.78 706.31D5_1.37m 218 1009.13 1356.74 12.25 1055.06 1439.42 136.25 674.05 753.61C6_1.39m 139 983.69 1310.95 12.75 1030.39 1395.02 139.25 655.06 719.41D5_1.45m 219 1023.55 1382.69 12.25 1071.05 1468.21 143.75 674.54 754.49C6_1.47m 140 998.61 1337.8 12.75 1046.3 1423.65 146.75 663.92 735.37D5_1.52m 220 1037.25 1407.36 12.75 1086.58 1496.16 152.75 680.19 764.66C6_1.62m 141 1021.86 1379.66 13.25 1073.26 1472.18 164.75 696.12 793.34D5_1.68m 221 1058.62 1445.83 13.25 1111.11 1540.31 172.25 722.75 841.26D5_1.78m 222 1043.92 1419.37 11.25 1093.16 1508 185.75 657.48 723.78D5_1.85m 223 1069 1464.51 11.75 1120.6 1557.38 192.75 673.85 753.24C6_1.87m 142 1048.68 1427.94 12.25 1102.81 1525.37 196.25 676.01 757.12D5_1.90m 224 1076.69 1478.36 11.75 1130.7 1575.58 198.25 685.89 774.91C6_1.95m 144 1056.63 1442.25 12.25 1111.76 1541.48 205.25 685.26 773.78C3_2.17m 178 1095.23 1511.72 12.75 1156.39 1621.82 226.25 728.7 851.97D4_2.24m 241 1096.23 1513.53 11.25 1153.61 1616.8 259.75 655.41 720.05D4_2.32m 242 1118.36 1553.36 11.25 1175.36 1655.96 267.25 684.27 772C3_2.35m 180 1109.57 1537.54 11.75 1168.8 1644.15 245.25 714.44 826.31D4_2.37m 243 1127.21 1569.29 11.25 1186.28 1675.61 274.25 690.42 783.06C3_2.40m 181 1114.65 1546.68 11.75 1175.2 1655.67 251.75 718.87 834.28D4_2.54m 245 1170.6 1647.4 11.25 1229.64 1753.66 299.75 708.59 815.77D6_2.62m 129 1166.43 1639.88 11.25 1226.61 1748.22 296.75 731.23 856.53D6_2.69m 130 1169.91 1646.15 11.25 1232.15 1758.19 308.25 742.59 876.97C3_2.76m 183 1172.97 1651.65 11.75 1235.68 1764.54 305.25 751.08 892.26D4_2.79m 247 1153.08 1615.85 10.75 1212.68 1723.13 339.75 670.6 747.39D6_2.87m 131 1123.6 1562.78 10.25 1178.73 1662.03 330.75 667.12 741.13D6_2.92m 132 1102.6 1524.99 11.75 1162.76 1633.28 337.25 689.66 781.7D6_2.97m 133 1076.53 1478.07 11.75 1133.08 1579.85 344.25 681.21 766.49D6_3.07m 134 1043.11 1417.91 11.75 1095.76 1512.69 352.75 666.47 739.96

E3_3.12m 197 1032.57 1398.94 11.75 1083.91 1491.34 361.75 663.92 735.37

D6_3.17m 135 1005.87 1350.88 11.75 1054.87 1439.09 361.75 651.84 713.62D6_3.27m 136 961.46 1270.94 12.25 1009.25 1356.96 369.75 621.38 658.79D4_3.61m 248 755.58 900.36 13.25 804.23 987.92 52.25 574.18 573.84
A-175 
A-176 
A-177 
A-178 

Heater Rod Temperature during Reflood 

RBHT Exp. 1170

400

500

600

700

800

900

1000

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

Temperature (K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1170

400

500

600

700

800

900

1000

1100

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

Temperature (K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)
A-179 

Heater Rod Temperature during Reflood 

RBHT Exp. 1170

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

Temperature (K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1170

400

500

600

700

800

900

1000

1100

1200

1300

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

Temperature (K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)
A-180 

Heater Rod Temperature during Reflood 

RBHT Exp. 1170

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

Temperature (K)

Chan. 195 2.93m (115.4in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.94m (115.7in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1170

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

Temperature (K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)
A-181 

Heater Rod Temperature during Reflood 

RBHT Exp. 1170

400

500

600

700

800

900

1000

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

Temperature (K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1170

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

Temperature (K)

Chan. 318 2.37m (93.5in)

Chan. 319 2.37m (93.5in)
A-182 

Steam Probe Temperature during Reflood 

RBHT Exp. 1170

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

Temperature (K)

Chan. 323 2.54m (100in)

Chan. 324 2.54m (100in)

Chan. 325 2.54m (100in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1170

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

Temperature (K)

Chan. 326 2.93m (115.4in)

Chan. 327 2.93m (115.4in)

Chan. 328 2.93m (115.4in)
A-183 

Steam Probe Temperature during Reflood 

RBHT Exp. 1170

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

Temperature (K)

Chan. 329 3.05m (120in)

Chan. 330 3.05m (120in)

Chan. 331 3.05m (120in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1170

400

500

600

700

800

900

1000

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

Temperature (K)

Chan. 332 3.45m (136in)

Chan. 333 3.45m (136in)

Chan. 334 3.45m (136in)
A-184 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1170

400

500

600

700

800

900

1000

1100

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

Temperature (K)

Chan. 260 1.75m (69in)

Chan. 261 1.75m (69in)

Spacer Grid Temperature during Reflood 

RBHT Exp. 1170

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

Temperature (K)

Chan. 266 2.26m (89in)

Chan. 267 2.26m (89in)
A-185 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1170

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

Temperature (K)

Chan. 272 2.79m (110in)

Chan. 273 2.79m (110in)

Chan. 275 2.79m (110in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1170

10

1000

100000

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)
A-186 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1170

10

1000

100000

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1170

10

1000

100000

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)
A-187 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1170

1

100

10000

1000000

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1170

1

100

10000

1000000

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 195 2.93m (115.5in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.93m (115.7in)
A-188 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1170

1

100

10000

1000000

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1170

1

100

10000

1000000

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)
A-189 

Quench Data, RBHT Exp. 1170

0

0.5

1

1.5

2

2.5

3

3.5

4

0 50 100 150 200 250 300 350 400

Time after Reflood (sec)

Elevation (m)

RBHT - REFLOOD TESTS 

SUMMARY SHEET 

RUN NO: 1196

RUN CONDITIONS

Upper Plenum Pressure: 276 kPa (40 psia) 

Initial Peak Clad Temperature: 1144 degrees K (1600 degrees F) 

Rod Peak Power: 2.3 kW/m (0.7 kW/ft) 

Flooding Rate: 0.1524 m/s (6 in/s) 

Inlet Subcooling: 53 degrees K (96 degrees F) 

Start of Reflood: 226.6 s 

End of Reflood: 718.7 s 

Test Date: 6/25/2002 
A-190 

Comments: No Droplet Data 

 Heater rod surfaces below 2.29 m (90 in) quench to a 

temperature below saturation due to the high inlet 

subcooling. Therefore DATARH calculated heat transfer 

coefficients are not presented below this elevation after rod 

quench. 
A-191 

Rod_Elevation Channel Temperature Temperature Turnaround Turnaround Turnaround Quench Quench Quench 

Number at Reflood (K) at Reflood ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F)

B6_0.592m 148 802.7 985.18 11.65 838.84 1050.23 34.15 692.59 786.97B6_0.744m 149 808.8 996.14 12.65 847.97 1066.65 43.65 659.63 727.65B6_0.846m 150 839.93 1052.19 13.15 883.72 1131.01 49.15 660.93 729.98B6_0.897m 151 852.7 1075.17 13.65 897.79 1156.33 54.15 632.91 679.55

C6_1.04m 137 904.99 1169.29 15.15 956.01 1261.14 62.15 651.18 712.44D5_1.27m 217 961.9 1271.73 15.15 1015.43 1368.08 74.65 655.66 720.5C6_1.34m 138 949.48 1249.38 15.65 1008.81 1356.17 78.15 650.31 710.88D5_1.37m 218 982.09 1308.08 15.65 1041.34 1414.72 84.15 639.46 691.35C6_1.39m 139 955.8 1260.75 15.65 1015.83 1368.81 84.65 652.83 715.4D5_1.45m 219 994.2 1329.86 15.65 1055.8 1440.76 89.15 647.73 706.23C6_1.47m 140 968.12 1282.94 16.15 1029.71 1393.79 91.65 622.85 661.45D5_1.52m 220 1005 1349.3 20.15 1069.4 1465.23 95.65 649.24 708.94C6_1.62m 141 985.53 1314.27 20.65 1054.68 1438.74 104.65 634.9 683.13D5_1.68m 221 1022.31 1380.47 20.65 1093.83 1509.2 110.15 634.61 682.62D5_1.78m 222 1006.68 1352.34 14.15 1068.8 1464.14 119.15 644.88 701.1D5_1.85m 223 1033.51 1400.62 14.65 1099.74 1519.84 125.65 621.87 659.68C6_1.87m 142 1011.64 1361.27 15.65 1081.19 1486.45 127.15 632.68 679.14D5_1.90m 224 1040.09 1412.47 15.15 1109.44 1537.3 130.15 630.37 674.98C6_1.95m 144 1018.03 1372.76 15.65 1089.86 1502.06 134.65 638.69 689.96C3_2.17m 178 1055.97 1441.05 15.65 1133.79 1581.13 161.65 665.1 737.48D4_2.24m 241 1057.34 1443.52 14.65 1129.03 1572.57 174.15 681.81 767.57D4_2.32m 242 1084.53 1492.47 14.15 1159.05 1626.6 183.15 647.44 705.7C3_2.35m 180 1077.6 1479.99 14.65 1154.82 1618.99 183.15 661.74 731.45D4_2.37m 243 1092.42 1506.66 14.65 1168.83 1644.21 189.65 662.83 733.41C3_2.40m 181 1082.33 1488.5 14.65 1160.97 1630.06 189.15 672.67 751.12D4_2.54m 245 1129.26 1572.98 14.15 1207 1712.92 216.15 692.16 786.2D6_2.62m 129 1117.66 1552.1 14.15 1197.17 1695.21 222.15 723.24 842.14D6_2.69m 130 1116.47 1549.96 14.65 1199.3 1699.04 236.15 731.82 857.6C3_2.76m 183 1121.59 1559.18 14.65 1203.87 1707.27 246.65 738.76 870.07D4_2.79m 247 1096.1 1513.29 13.65 1175.92 1656.97 263.15 704.92 809.16D6_2.87m 131 1062.44 1452.7 13.15 1136.57 1586.15 267.15 670.71 747.59D6_2.92m 132 1038.62 1409.82 14.65 1118.88 1554.29 273.65 679.36 763.17D6_2.97m 133 1010.43 1359.08 15.15 1086.97 1496.85 281.15 689.27 780.99D6_3.07m 134 974.02 1293.54 15.15 1045.73 1422.62 291.65 681.59 767.17

E3_3.12m 197 977.46 1299.73 14.65 1048.54 1427.68 304.15 676.53 758.06

D6_3.17m 135 936.96 1226.84 15.15 1004.18 1347.84 303.15 691.75 785.47D6_3.27m 136 889.22 1140.91 16.15 954.5 1258.41 315.65 685.4 774.04D4_3.61m 248 668.72 744 17.15 738.05 868.8 489.65 407.72 274.2
A-192 
A-193 
A-194 
A-195 

Heater Rod Temperature during Reflood 

RBHT Exp. 1196

300

400

500

600

700

800

900

1000

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

Temperature (K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1196

300

400

500

600

700

800

900

1000

1100

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

Temperature (K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)
A-196 

Heater Rod Temperature during Reflood 

RBHT Exp. 1196

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

Temperature (K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1196

400

500

600

700

800

900

1000

1100

1200

1300

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

Temperature (K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)
A-197 

Heater Rod Temperature during Reflood 

RBHT Exp. 1196

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

Temperature (K)

Chan. 195 2.93m (115.4in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.94m (115.7in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1196

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

Temperature (K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)
A-198 

Heater Rod Temperature during Reflood 

RBHT Exp. 1196

400

500

600

700

800

900

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

Temperature (K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1196

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

Temperature (K)

Chan. 318 2.37m (93.5in)

Chan. 319 2.37m (93.5in)
A-199 

Steam Probe Temperature during Reflood 

RBHT Exp. 1196

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

Temperature (K)

Chan. 323 2.54m (100in)

Chan. 324 2.54m (100in)

Chan. 325 2.54m (100in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1196

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

Temperature (K)

Chan. 326 2.93m (115.4in)

Chan. 327 2.93m (115.4in)

Chan. 328 2.93m (115.4in)
A-200 

Steam Probe Temperature during Reflood 

RBHT Exp. 1196

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

Temperature (K)

Chan. 329 3.05m (120in)

Chan. 330 3.05m (120in)

Chan. 331 3.05m (120in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1196

400

500

600

700

800

900

1000

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

Temperature (K)

Chan. 332 3.45m (136in)

Chan. 333 3.45m (136in)

Chan. 334 3.45m (136in)
A-201 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1196

300

400

500

600

700

800

900

1000

1100

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

Temperature (K)

Chan. 260 1.75m (69in)

Chan. 261 1.75m (69in)

Spacer Grid Temperature during Reflood 

RBHT Exp. 1196

300

400

500

600

700

800

900

1000

1100

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

Temperature (K)

Chan. 266 2.26m (89in)

Chan. 267 2.26m (89in)
A-202 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1196

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

Temperature (K)

Chan. 272 2.79m (110in)

Chan. 273 2.79m (110in)

Chan. 275 2.79m (110in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1196

10

1000

100000

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)
A-203 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1196

10

1000

100000

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1196

10

1000

100000

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)
A-204 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1196

1

100

10000

1000000

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1196

1

100

10000

1000000

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 195 2.93m (115.5in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.93m (115.7in)
A-205 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1196

1

100

10000

1000000

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1196

1

100

10000

1000000

0 50 100 150 200 250 300 350 400 450 500

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)
A-206 

Quench Data, RBHT Exp. 1196

0

0.5

1

1.5

2

2.5

3

3.5

4

0 100 200 300 400 500

Time after Reflood (sec)

Elevation (m)
A-207 

RBHT - REFLOOD TESTS 

SUMMARY SHEET 

RUN NO: 1202

RUN CONDITIONS

Upper Plenum Pressure: 276 kPa (40 psia) 

Initial Peak Clad Temperature: 1144 degrees K (1600 degrees F) 

Rod Peak Power: 2.3 kW/m (0.7 kW/ft) 

Flooding Rate: 0.1524 m/s (6 in/s) 

Inlet Subcooling: 23 degrees K (42 degrees F) 

Start of Reflood: 258.5 s 

End of Reflood: 801.7 s 

Test Date: 6/26/2002 

Comments: No droplet data 
A-208 

Rod_Elevation Channel Temperature Temperature Turnaround Turnaround Turnaround Quench Quench Quench 

Number at Reflood (K) at Reflood ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F)

B6_0.592m 148 785.2 953.67 12.75 826.38 1027.8 53.75 601.82 623.59B6_0.744m 149 793.17 968.02 13.75 838.07 1048.83 67.75 594.16 609.8B6_0.846m 150 832.62 1039.03 15.25 881.9 1127.73 76.75 604.66 628.71B6_0.897m 151 846.74 1064.44 15.25 897.77 1156.29 81.25 609.06 636.62

C6_1.04m 137 899.19 1158.85 15.75 954.66 1258.71 92.75 639.32 691.09D5_1.27m 217 953.82 1257.19 15.25 1013.81 1365.18 115.75 626.45 667.91C6_1.34m 138 943.26 1238.19 16.25 1006.86 1352.66 122.25 640.6 693.39D5_1.37m 218 975.26 1295.78 16.25 1039.42 1411.27 125.25 659.19 726.85C6_1.39m 139 949.78 1249.92 16.25 1014.06 1365.62 127.25 653.78 717.12D5_1.45m 219 987.26 1317.39 16.25 1053.52 1436.65 132.75 661.59 731.17C6_1.47m 140 962.65 1273.09 16.25 1027.99 1390.69 135.25 658.22 725.1D5_1.52m 220 998.37 1337.38 16.25 1066.31 1459.67 141.25 669.88 746.1C6_1.62m 141 981.42 1306.87 16.75 1052.3 1434.46 153.25 683.3 770.25D5_1.68m 221 1017.85 1372.43 17.25 1090.43 1503.08 160.75 706.07 811.25D5_1.78m 222 1000.69 1341.56 15.25 1069.11 1464.71 174.75 674.22 753.9D5_1.85m 223 1029.2 1392.88 15.75 1101.96 1523.84 182.25 666.46 739.93C6_1.87m 142 1008.66 1355.9 16.25 1083.89 1491.31 185.25 675.83 756.8D5_1.90m 224 1037.05 1407 15.75 1112.8 1543.35 187.75 689.2 780.87C6_1.95m 144 1016.74 1370.45 16.25 1093.92 1509.36 194.75 692.61 787.01C3_2.17m 178 1060.58 1449.35 16.75 1143.98 1599.48 228.25 736.63 866.24D4_2.24m 241 1062.08 1452.05 15.75 1138.89 1590.31 257.75 676.06 757.22D4_2.32m 242 1092.44 1506.7 15.25 1173.75 1653.06 269.25 697.53 795.87C3_2.35m 180 1085.18 1493.63 15.75 1169.22 1644.91 253.25 727.72 850.21D4_2.37m 243 1100.75 1521.65 15.25 1184.09 1671.68 277.75 707.88 814.49C3_2.40m 181 1089.25 1500.96 15.75 1174.93 1655.18 261.25 734.78 862.91D4_2.54m 245 1130.93 1575.98 15.25 1216.07 1729.23 310.25 710.26 818.78D6_2.62m 129 1119.25 1554.97 15.25 1207.24 1713.34 306.25 738.45 869.52D6_2.69m 130 1116.66 1550.3 15.25 1206.92 1712.76 319.75 749.49 889.4C3_2.76m 183 1119.31 1555.06 15.75 1208.58 1715.76 324.25 761.46 910.94D4_2.79m 247 1093.75 1509.06 14.75 1179.97 1664.26 357.75 686.13 775.35D6_2.87m 131 1059.62 1447.62 14.75 1140.88 1593.89 346.25 681.91 767.74D6_2.92m 132 1037.1 1407.1 15.75 1123.33 1562.3 353.25 702.94 805.6D6_2.97m 133 1011.16 1360.39 15.75 1092.56 1506.92 360.75 682.03 767.96D6_3.07m 134 977.86 1300.47 16.25 1053.28 1436.22 369.75 667.06 741.03

E3_3.12m 197 987.23 1317.32 16.25 1061.33 1450.71 390.75 663.43 734.49

D6_3.17m 135 943.69 1238.95 16.25 1013.75 1365.07 378.75 658.9 726.33D6_3.27m 136 897.32 1155.48 16.25 965.05 1277.4 387.25 626.8 668.56D4_3.61m 248 682.83 769.4 17.25 752.89 895.52 62.25 559.36 547.16
A-209 
A-210 
A-211 
A-212 

Heater Rod Temperature during Reflood 

RBHT Exp. 1202

400

500

600

700

800

900

1000

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1202

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)
A-213 

Heater Rod Temperature during Reflood 

RBHT Exp. 1202

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1202

400

500

600

700

800

900

1000

1100

1200

1300

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)
A-214 

Heater Rod Temperature during Reflood 

RBHT Exp. 1202

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 195 2.93m (115.4in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.94m (115.7in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1202

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)
A-215 

Heater Rod Temperature during Reflood 

RBHT Exp. 1202

400

500

600

700

800

900

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1202

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 318 2.37m (93.5in)

Chan. 319 2.37m (93.5in)
A-216 

Steam Probe Temperature during Reflood 

RBHT Exp. 1202

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 323 2.54m (100in)

Chan. 324 2.54m (100in)

Chan. 325 2.54m (100in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1202

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 326 2.93m (115.4in)

Chan. 327 2.93m (115.4in)

Chan. 328 2.93m (115.4in)
A-217 

Steam Probe Temperature during Reflood 

RBHT Exp. 1202

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 329 3.05m (120in)

Chan. 330 3.05m (120in)

Chan. 331 3.05m (120in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1202

400

500

600

700

800

900

1000

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 332 3.45m (136in)

Chan. 333 3.45m (136in)

Chan. 334 3.45m (136in)
A-218 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1202

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 260 1.75m (69in)

Chan. 261 1.75m (69in)

Spacer Grid Temperature during Reflood 

RBHT Exp. 1202

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 266 2.26m (89in)

Chan. 267 2.26m (89in)
A-219 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1202

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 272 2.79m (110in)

Chan. 273 2.79m (110in)

Chan. 275 2.79m (110in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1202

10

1000

100000

0 100 200 300 400 500 600

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)
A-220 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1202

10

1000

100000

0 100 200 300 400 500 600

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1202

10

1000

100000

0 100 200 300 400 500 600

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)
A-221 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1202

1

100

10000

1000000

0 100 200 300 400 500 600

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1202

1

100

10000

1000000

0 100 200 300 400 500 600

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 195 2.93m (115.5in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.93m (115.7in)
A-222 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1202

1

100

10000

1000000

0 100 200 300 400 500 600

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1202

1

100

10000

1000000

0 100 200 300 400 500 600

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)
A-223 

Quench Data, RBHT Exp. 1202

0

0.5

1

1.5

2

2.5

3

3.5

4

0 100 200 300 400 500

Time after Reflood (sec)

Elevation (m)
A-224 

RBHT - REFLOOD TESTS 

SUMMARY SHEET 

RUN NO: 1223

RUN CONDITIONS

Upper Plenum Pressure: 276 kPa (40 psia) 

Initial Peak Clad Temperature: 1144 degrees K (1600 degrees F) 

Rod Peak Power: 2.3 kW/m (0.7 kW/ft) 

Flooding Rate: 0.1524 m/s (6 in/s) 

Inlet Subcooling: 11 degrees K (20 degrees F) 

Start of Reflood: 135.2 s 

End of Reflood: 788.6 s 

Test Date: 6/28/2002 

Comments: No droplet data 
A-225 

Rod_Elevation Channel Temperature Temperature Turnaround Turnaround Turnaround Quench Quench Quench 

Number at Reflood (K) at Reflood ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F)

B6_0.592m 148 815.75 1008.67 8.05 841.44 1054.9 57.05 604.52 628.45B6_0.744m 149 814.49 1006.4 9.05 842.14 1056.17 73.55 595.32 611.89B6_0.846m 150 863.85 1095.25 9.05 893.99 1149.5 82.55 624.38 664.2B6_0.897m 151 876.88 1118.69 9.05 908.08 1174.86 88.05 632.66 679.1

C6_1.04m 137 929.28 1213.01 10.05 965.39 1278.01 101.55 663.86 735.27D5_1.27m 217 986.93 1316.79 9.55 1024.03 1383.57 127.55 635.06 683.43C6_1.34m 138 978.65 1301.87 10.55 1019.77 1375.9 132.05 654.93 719.18D5_1.37m 218 1010.85 1359.84 10.05 1051.34 1432.73 138.55 668.55 743.71C6_1.39m 139 984.71 1312.8 10.55 1026.4 1387.84 137.55 669.03 744.57D5_1.45m 219 1023.55 1382.7 10.05 1065.5 1458.21 146.55 672.62 751.02C6_1.47m 140 997.01 1334.93 10.55 1039.86 1412.07 146.05 663.72 735D5_1.52m 220 1035.14 1403.56 10.55 1078.69 1481.96 155.55 675.9 756.93C6_1.62m 141 1017.25 1371.36 11.05 1063.39 1454.41 164.05 696.84 794.62D5_1.68m 221 1056.13 1441.35 11.05 1102.5 1524.81 175.05 715.94 829.01D5_1.78m 222 1025.41 1386.04 10.05 1069.11 1464.71 188.55 658.7 725.97D5_1.85m 223 1065.98 1459.08 10.05 1111.09 1540.28 195.55 673.38 752.4C6_1.87m 142 1046.34 1423.73 10.55 1094.18 1509.84 195.55 679.34 763.13D5_1.90m 224 1077.53 1479.87 10.05 1125.11 1565.51 201.55 683.68 770.93C6_1.95m 144 1057.99 1444.69 10.55 1106.75 1532.46 204.55 692.25 786.36C3_2.17m 178 1111.34 1540.73 10.55 1164.78 1636.91 229.55 732.41 858.66D4_2.24m 241 1102.01 1523.94 10.05 1151.56 1613.13 260.55 658.89 726.32D4_2.32m 242 1143.71 1598.99 9.55 1194.86 1691.07 270.05 691.88 785.69C3_2.35m 180 1139.61 1591.61 10.05 1193.57 1688.73 250.05 721 838.11D4_2.37m 243 1153.21 1616.1 9.55 1205.81 1710.76 277.55 706.4 811.83C3_2.40m 181 1143.16 1598 10.05 1198.42 1697.47 257.05 728.15 850.98D4_2.54m 245 1182.24 1668.34 9.55 1234.08 1761.65 306.55 705.27 809.8D6_2.62m 129 1172.6 1650.99 9.55 1226.25 1747.56 302.05 740.86 873.86D6_2.69m 130 1174.06 1653.61 9.55 1228.88 1752.3 314.55 746.06 883.21C3_2.76m 183 1173.74 1653.05 9.55 1228.42 1751.46 313.55 752.44 894.7D6_2.92m 132 1084.66 1492.71 10.05 1138.96 1590.44 344.55 701.9 803.74D6_2.97m 133 1052.16 1434.21 10.55 1103.96 1527.45 352.05 686.13 775.34D6_3.07m 134 1011.27 1360.61 10.55 1058.82 1446.19 360.55 672.82 751.4

E3_3.12m 197 1018.93 1374.39 10.05 1065.54 1458.28 372.05 670.16 746.59

D6_3.17m 135 975.12 1295.53 10.55 1018.73 1374.03 369.55 658.76 726.07D6_3.27m 136 923.94 1203.4 10.55 966.94 1280.81 378.05 620.05 656.4D4_3.61m 248 708.78 816.12 10.55 761.21 910.49 40.05 569 564.52
A-226 
A-227 
A-228 
A-229 

Heater Rod Temperature during Reflood 

RBHT Exp. 1223

400

500

600

700

800

900

1000

0 100 200 300 400 500 600 700

Time after Reflood (sec)

Temperature (K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1223

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700

Time after Reflood (sec)

Temperature (K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)
A-230 

Heater Rod Temperature during Reflood 

RBHT Exp. 1223

400

500

600

700

800

900

1000

1100

1200

1300

0 100 200 300 400 500 600 700

Time after Reflood (sec)

Temperature (K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1223

400

500

600

700

800

900

1000

1100

1200

1300

0 100 200 300 400 500 600 700

Time after Reflood (sec)

Temperature (K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)
A-231 

Heater Rod Temperature during Reflood 

RBHT Exp. 1223

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600 700

Time after Reflood (sec)

Temperature (K)

Chan. 195 2.93m (115.4in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.94m (115.7in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1223

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600 700

Time after Reflood (sec)

Temperature (K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)
A-232 

Heater Rod Temperature during Reflood 

RBHT Exp. 1223

400

500

600

700

800

900

0 100 200 300 400 500 600 700

Time after Reflood (sec)

Temperature (K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1223

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600 700

Time after Reflood (sec)

Temperature (K)

Chan. 318 2.37m (93.5in)

Chan. 319 2.37m (93.5in)
A-233 

Steam Probe Temperature during Reflood 

RBHT Exp. 1223

400

500

600

700

800

900

1000

1100

1200

1300

0 100 200 300 400 500 600 700

Time after Reflood (sec)

Temperature (K)

Chan. 323 2.54m (100in)

Chan. 324 2.54m (100in)

Chan. 325 2.54m (100in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1223

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600 700

Time after Reflood (sec)

Temperature (K)

Chan. 326 2.93m (115.4in)

Chan. 327 2.93m (115.4in)

Chan. 328 2.93m (115.4in)
A-234 

Steam Probe Temperature during Reflood 

RBHT Exp. 1223

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600 700

Time after Reflood (sec)

Temperature (K)

Chan. 329 3.05m (120in)

Chan. 330 3.05m (120in)

Chan. 331 3.05m (120in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1223

400

500

600

700

800

900

1000

0 100 200 300 400 500 600 700

Time after Reflood (sec)

Temperature (K)

Chan. 332 3.45m (136in)

Chan. 333 3.45m (136in)

Chan. 334 3.45m (136in)
A-235 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1223

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700

Time after Reflood (sec)

Temperature (K)

Chan. 260 1.75m (69in)

Chan. 261 1.75m (69in)

Spacer Grid Temperature during Reflood 

RBHT Exp. 1223

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600 700

Time after Reflood (sec)

Temperature (K)

Chan. 266 2.26m (89in)

Chan. 267 2.26m (89in)
A-236 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1223

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600 700

Time after Reflood (sec)

Temperature (K)

Chan. 272 2.79m (110in)

Chan. 273 2.79m (110in)

Chan. 275 2.79m (110in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1223

10

1000

100000

0 100 200 300 400 500 600 700

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)
A-237 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1223

10

1000

100000

0 100 200 300 400 500 600 700

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1223

10

1000

100000

0 100 200 300 400 500 600 700

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)
A-238 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1223

1

100

10000

1000000

0 100 200 300 400 500 600 700

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1223

1

100

10000

1000000

0 100 200 300 400 500 600 700

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 195 2.93m (115.5in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.93m (115.7in)
A-239 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1223

1

100

10000

1000000

0 100 200 300 400 500 600 700

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1223

1

100

10000

1000000

0 100 200 300 400 500 600 700

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)
A-240 

Quench Data, RBHT Exp. 1223

0

0.5

1

1.5

2

2.5

3

3.5

4

0 100 200 300 400 500

Time after Reflood (sec)

Elevation (m)
A-241 

RBHT - REFLOOD TESTS 

SUMMARY SHEET 

RUN NO: 1228

RUN CONDITIONS

Upper Plenum Pressure: 138 kPa (20 psia) 

Initial Peak Clad Temperature: 1144 degrees K (1600 degrees F) 

Rod Peak Power: 2.3 kW/m (0.7 kW/ft) 

Flooding Rate: 0.1524 m/s (6 in/s) 

Inlet Subcooling: 23 degrees K (42 degrees F) 

Start of Reflood: 120.5 s 

End of Reflood: 1112.5 s 

Test Date: 7/1/2002 

Comments: No droplet data 
A-242 

Rod_Elevation Channel Temperature Temperature Turnaround Turnaround Turnaround Quench Quench Quench 

Number at Reflood (K) at Reflood ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F)

B6_0.592m 148 761.37 910.79 12.25 800.53 981.26 52.25 590.12 602.53B6_0.744m 149 776.89 938.72 14.75 820.55 1017.3 68.25 569.43 565.29B6_0.846m 150 803.11 985.91 15.75 851.66 1073.3 81.25 580.75 585.66B6_0.897m 151 812.78 1003.31 15.75 861.96 1091.83 88.25 581.18 586.43

C6_1.04m 137 859.65 1087.68 18.75 915.55 1188.29 106.75 606.47 631.95C6_1.34m 138 912.79 1183.33 17.25 975.55 1296.3 154.75 625.78 666.72C6_1.39m 139 917.65 1192.09 18.75 981.61 1307.2 163.75 636.32 685.68C6_1.47m 140 929.36 1213.17 18.25 995.12 1331.53 178.25 649.39 709.21C6_1.62m 141 949.36 1249.16 19.25 1021.57 1379.15 212.25 683.07 769.84C6_1.87m 142 986.16 1315.41 16.25 1058.02 1444.75 273.25 695.27 791.8C6_1.95m 144 995.36 1331.95 16.75 1069.61 1465.61 291.75 716.68 830.34D6_2.62m 129 1117.36 1551.56 14.75 1199.02 1698.54 480.25 762.28 912.42D6_2.69m 130 1117.63 1552.05 15.25 1201.77 1703.5 500.75 774.97 935.25D6_2.87m 131 1064.17 1455.81 13.25 1136.96 1586.85 540.25 699.19 798.85D6_2.92m 132 1037.96 1408.63 14.75 1116.51 1550.04 551.25 728.65 851.89D6_2.97m 133 1005.08 1349.46 15.25 1080.49 1485.19 563.75 718.04 832.79D6_3.07m 134 960.71 1269.6 15.25 1031.78 1397.52 578.75 702.73 805.23D6_3.17m 135 917.39 1191.62 15.25 983.51 1310.62 594.75 686.51 776.02D6_3.27m 136 866.18 1099.44 15.75 930.27 1214.8 608.75 630.77 675.69D5_1.27m 217 923.51 1202.64 16.25 981.83 1307.6 143.75 614.81 646.97D5_1.37m 218 941.91 1235.75 17.75 1005.95 1351.03 160.25 640.83 693.8D5_1.45m 219 953.44 1256.5 17.75 1019.46 1375.34 173.25 643.04 697.79D5_1.52m 220 964.76 1276.88 17.75 1033.35 1400.34 188.75 661.88 731.7D5_1.68m 221 984.96 1313.24 19.25 1059.27 1447.01 224.25 706.29 811.63D5_1.78m 222 974.11 1293.71 14.75 1038.28 1409.22 249.75 690.18 782.63D5_1.85m 223 1005.49 1350.2 15.25 1073.94 1473.41 265.25 684.55 772.5D5_1.90m 224 1014.7 1366.78 15.75 1086.33 1495.71 276.25 703.72 807.01D4_2.24m 241 1062.56 1452.92 14.75 1132.05 1578.01 400.25 683.94 771.41D4_2.32m 242 1095.9 1512.93 14.75 1170.79 1647.73 419.25 727.9 850.53D4_2.37m 243 1104.91 1529.15 14.75 1182 1667.91 434.75 719.65 835.69D4_2.54m 245 1129.86 1574.07 14.75 1208.63 1715.85 489.25 733.89 861.32D4_2.79m 247 1096.23 1513.52 13.25 1172.44 1650.71 564.75 694.15 789.78D4_3.61m 248 611.47 640.95 16.75 682.33 768.51 39.75 514.89 467.12C3_2.17m 178 1052.4 1434.63 16.75 1132 1577.92 351.75 751.25 892.56

E3_3.12m 197 961.01 1270.12 15.25 1030.23 1394.73 614.25 684.22 771.92

C3_2.35m 180 1090.85 1503.84 14.75 1168.46 1643.54 394.75 753.38 896.39C3_2.40m 181 1094.62 1510.63 15.25 1173.7 1652.97 408.75 762.24 912.34C3_2.76m 183 1122.24 1560.35 15.25 1206 1711.11 510.75 775.34 935.92
A-243 
A-244 
A-245 
A-246 

Heater Rod Temperature during Reflood 

RBHT Exp. 1228

300

400

500

600

700

800

900

0 100 200 300 400 500 600 700 800 900 1000

Time after Reflood (sec)

Temperature (K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1228

300

400

500

600

700

800

900

1000

0 100 200 300 400 500 600 700 800 900 1000

Time after Reflood (sec)

Temperature (K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)
A-247 

Heater Rod Temperature during Reflood 

RBHT Exp. 1228

300

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600 700 800 900 1000

Time after Reflood (sec)

Temperature (K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1228

300

400

500

600

700

800

900

1000

1100

1200

1300

0 100 200 300 400 500 600 700 800 900 1000

Time after Reflood (sec)

Temperature (K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)
A-248 

Heater Rod Temperature during Reflood 

RBHT Exp. 1228

300

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600 700 800 900 1000

Time after Reflood (sec)

Temperature (K)

Chan. 195 2.93m (115.4in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.94m (115.7in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1228

300

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800 900 1000

Time after Reflood (sec)

Temperature (K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)
A-249 

Heater Rod Temperature during Reflood 

RBHT Exp. 1228

300

400

500

600

700

800

900

0 100 200 300 400 500 600 700 800 900 1000

Time after Reflood (sec)

Temperature (K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1228

300

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600 700 800 900 1000

Time after Reflood (sec)

Temperature (K)

Chan. 318 2.37m (93.5in)

Chan. 319 2.37m (93.5in)
A-250 

Steam Probe Temperature during Reflood 

RBHT Exp. 1228

300

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600 700 800 900 1000

Time after Reflood (sec)

Temperature (K)

Chan. 323 2.54m (100in)

Chan. 324 2.54m (100in)

Chan. 325 2.54m (100in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1228

300

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600 700 800 900 1000

Time after Reflood (sec)

Temperature (K)

Chan. 326 2.93m (115.4in)

Chan. 327 2.93m (115.4in)

Chan. 328 2.93m (115.4in)
A-251 

Steam Probe Temperature during Reflood 

RBHT Exp. 1228

300

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600 700 800 900 1000

Time after Reflood (sec)

Temperature (K)

Chan. 329 3.05m (120in)

Chan. 330 3.05m (120in)

Chan. 331 3.05m (120in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1228

300

400

500

600

700

800

900

1000

0 100 200 300 400 500 600 700 800 900 1000

Time after Reflood (sec)

Temperature (K)

Chan. 332 3.45m (136in)

Chan. 333 3.45m (136in)

Chan. 334 3.45m (136in)
A-252 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1228

300

400

500

600

700

800

900

1000

0 100 200 300 400 500 600 700 800 900 1000

Time after Reflood (sec)

Temperature (K)

Chan. 260 1.75m (69in)

Chan. 261 1.75m (69in)

Spacer Grid Temperature during Reflood 

RBHT Exp. 1228

300

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800 900 1000

Time after Reflood (sec)

Temperature (K)

Chan. 266 2.26m (89in)

Chan. 267 2.26m (89in)
A-253 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1228

300

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600 700 800 900 1000

Time after Reflood (sec)

Temperature (K)

Chan. 272 2.79m (110in)

Chan. 273 2.79m (110in)

Chan. 275 2.79m (110in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1228

10

1000

100000

0 100 200 300 400 500 600 700 800 900 1000

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)
A-254 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1228

10

1000

100000

0 100 200 300 400 500 600 700 800 900 1000

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1228

10

1000

100000

0 100 200 300 400 500 600 700 800 900 1000

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)
A-255 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1228

1

100

10000

1000000

0 100 200 300 400 500 600 700 800 900 1000

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1228

1

100

10000

1000000

0 100 200 300 400 500 600 700 800 900 1000

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 195 2.93m (115.5in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.93m (115.7in)
A-256 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1228

1

100

10000

1000000

0 100 200 300 400 500 600 700 800 900 1000

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1228

1

100

10000

1000000

100000000

0 100 200 300 400 500 600 700 800 900 1000

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)
A-257 

Quench Data, RBHT Exp. 1228

0

0.5

1

1.5

2

2.5

3

3.5

4

0 100 200 300 400 500 600 700

Time after Reflood (sec)

Elevation (m)
A-258 

RBHT - REFLOOD TESTS 

SUMMARY SHEET 

RUN NO: 1280

RUN CONDITIONS

Upper Plenum Pressure: 138 kPa (20 psia) 

Initial Peak Clad Temperature: 1144 degrees K (1600 degrees F) 

Rod Peak Power: 2.3 kW/m (0.7 kW/ft) 

Flooding Rate: 0.1524 m/s (6 in/s) 

Inlet Subcooling: 83 degrees K (150 degrees F) 

Start of Reflood: 173.2 s 

End of Reflood: 506.2 s 

Test Date: 7/17/2002 

Comments: No Droplet Data 

Heater rod surfaces below 2.54 m (100 in) quench to a 

temperature below saturation due to the high inlet 

subcooling. Therefore DATARH calculated heat transfer 

coefficients are not presented below this elevation after rod 

quench. 
A-259 

Rod_Elevation Channel Temperature Temperature Turnaround Turnaround Turnaround Quench Quench Quench 

Number at Reflood (K) at Reflood ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F)

B6_0.592m 148 775.59 936.37 8.55 802.21 984.3 25.55 694.65 790.69B6_0.744m 149 802.94 985.6 9.55 832.6 1038.99 30.55 705.74 810.64B6_0.846m 150 824.46 1024.35 11.05 858.84 1086.22 34.55 707.4 813.64B6_0.897m 151 833.22 1040.11 11.55 869.42 1105.27 35.55 723.97 843.45

C6_1.04m 137 880.16 1124.6 16.55 921.35 1198.74 42.05 733.83 861.2D5_1.27m 217 951.56 1253.12 14.05 993 1327.71 51.55 759.24 906.94C6_1.34m 138 935.21 1223.68 15.05 982.39 1308.62 54.55 744.99 881.3D5_1.37m 218 968.15 1282.98 16.05 1015.24 1367.74 58.55 738.21 869.09C6_1.39m 139 938.85 1230.24 16.55 987.31 1317.47 59.05 736.16 865.39D5_1.45m 219 978.45 1301.51 16.55 1027.38 1389.59 62.05 746.83 884.61C6_1.47m 140 949.82 1249.99 16.05 999.85 1340.05 63.05 735.87 864.88D5_1.52m 220 988.33 1319.31 16.55 1040.04 1412.39 66.55 742.83 877.41C6_1.62m 141 967.35 1281.55 18.05 1024.83 1385 71.55 763.62 914.82D5_1.68m 221 1005.85 1350.84 17.55 1064.34 1456.13 76.05 746.29 883.63D5_1.78m 222 993.19 1328.05 11.05 1037.95 1408.62 82.05 702.35 804.54D5_1.85m 223 1023.02 1381.75 11.05 1071.24 1468.54 86.05 695.53 792.27C6_1.87m 142 1000.1 1340.5 12.05 1052.33 1434.5 88.05 702.29 804.44D5_1.90m 224 1029.41 1393.24 12.05 1081.03 1486.16 89.05 698.22 797.1C6_1.95m 144 1006.44 1351.91 12.55 1061 1450.11 93.05 704.41 808.25C3_2.17m 178 1043.61 1418.82 10.55 1094.95 1511.22 111.55 683.94 771.4D4_2.24m 241 1088.62 1499.82 10.05 1137.84 1588.42 116.05 662.76 733.28D4_2.32m 242 1097.62 1516.03 10.55 1151.69 1613.35 122.55 696.25 793.56C3_2.35m 180 1089.89 1502.11 11.05 1147.39 1605.61 126.05 684.96 773.24D4_2.37m 243 1104.1 1527.69 10.55 1159.62 1627.64 127.05 713.15 823.98C3_2.40m 181 1091.96 1505.84 11.05 1149.79 1609.93 131.55 684.65 772.69D4_2.54m 245 1126.86 1568.66 10.55 1182.64 1669.07 148.05 689.84 782.03D6_2.62m 129 1115.25 1547.76 10.55 1173.44 1652.5 158.05 690.49 783.19D6_2.69m 130 1116.39 1549.81 11.05 1175.5 1656.21 169.05 699.51 799.43C3_2.76m 183 1116.78 1550.52 11.05 1176.49 1657.99 182.05 684.8 772.95D4_2.79m 247 1091.36 1504.76 9.05 1142.44 1596.7 187.05 657.69 724.16D6_2.87m 131 1066.87 1460.68 9.05 1117.04 1550.98 199.55 628.44 671.5D6_2.92m 132 1039.4 1411.22 10.55 1095.67 1512.52 209.05 633.49 680.59D6_2.97m 133 1008.24 1355.14 11.05 1062.59 1452.98 220.05 626.21 667.5D6_3.07m 134 967.25 1281.37 11.05 1018.38 1373.39 235.05 623.27 662.2

E3_3.12m 197 965.95 1279.02 10.55 1015.91 1368.95 245.55 607.1 633.1

D6_3.17m 135 926.7 1208.36 11.05 974.56 1294.52 252.55 620.13 656.55D6_3.27m 136 880.35 1124.94 11.55 926.19 1207.46 215.05 562.71 553.19D4_3.61m 248 623.01 661.73 12.55 678.09 760.87 42.05 476.4 397.83
A-260 
A-261 
A-262 
A-263 

Heater Rod Temperature during Reflood 

RBHT Exp. 1280

300

400

500

600

700

800

900

0 50 100 150 200 250 300 350

Time after Reflood (sec)

Temperature (K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1280

300

400

500

600

700

800

900

1000

0 50 100 150 200 250 300 350

Time after Reflood (sec)

Temperature (K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)
A-264 

Heater Rod Temperature during Reflood 

RBHT Exp. 1280

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350

Time after Reflood (sec)

Temperature (K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1280

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350

Time after Reflood (sec)

Temperature (K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)
A-265 

Heater Rod Temperature during Reflood 

RBHT Exp. 1280

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350

Time after Reflood (sec)

Temperature (K)

Chan. 195 2.93m (115.4in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.94m (115.7in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1280

300

400

500

600

700

800

900

1000

1100

0 50 100 150 200 250 300 350

Time after Reflood (sec)

Temperature (K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)
A-266 

Heater Rod Temperature during Reflood 

RBHT Exp. 1280

300

400

500

600

700

800

900

0 50 100 150 200 250 300 350

Time after Reflood (sec)

Temperature (K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1280

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350

Time after Reflood (sec)

Temperature (K)

Chan. 318 2.37m (93.5in)

Chan. 319 2.37m (93.5in)
A-267 

Steam Probe Temperature during Reflood 

RBHT Exp. 1280

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350

Time after Reflood (sec)

Temperature (K)

Chan. 323 2.54m (100in)

Chan. 324 2.54m (100in)

Chan. 325 2.54m (100in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1280

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350

Time after Reflood (sec)

Temperature (K)

Chan. 326 2.93m (115.4in)

Chan. 327 2.93m (115.4in)

Chan. 328 2.93m (115.4in)
A-268 

Steam Probe Temperature during Reflood 

RBHT Exp. 1280

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350

Time after Reflood (sec)

Temperature (K)

Chan. 329 3.05m (120in)

Chan. 330 3.05m (120in)

Chan. 331 3.05m (120in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1280

300

400

500

600

700

800

900

1000

0 50 100 150 200 250 300 350

Time after Reflood (sec)

Temperature (K)

Chan. 332 3.45m (136in)

Chan. 333 3.45m (136in)

Chan. 334 3.45m (136in)
A-269 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1280

300

400

500

600

700

800

900

1000

0 50 100 150 200 250 300 350

Time after Reflood (sec)

Temperature (K)

Chan. 260 1.75m (69in)

Chan. 261 1.75m (69in)

Spacer Grid Temperature during Reflood 

RBHT Exp. 1280

300

400

500

600

700

800

900

1000

1100

0 50 100 150 200 250 300 350

Time after Reflood (sec)

Temperature (K)

Chan. 266 2.26m (89in)

Chan. 267 2.26m (89in)
A-270 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1280

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350

Time after Reflood (sec)

Temperature (K)

Chan. 272 2.79m (110in)

Chan. 273 2.79m (110in)

Chan. 275 2.79m (110in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1280

10

1000

100000

0 50 100 150 200 250 300 350

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)
A-271 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1280

10

1000

100000

0 50 100 150 200 250 300 350

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1280

10

1000

100000

10000000

0 50 100 150 200 250 300 350

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)
A-272 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1280

1

100

10000

1000000

0 50 100 150 200 250 300 350

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1280

1

100

10000

1000000

0 50 100 150 200 250 300 350

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 195 2.93m (115.5in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.93m (115.7in)
A-273 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1280

1

100

10000

1000000

0 50 100 150 200 250 300 350

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1280

1

100

10000

1000000

100000000

0 50 100 150 200 250 300 350

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)
A-274 

Quench Data, RBHT Exp. 1280

0

0.5

1

1.5

2

2.5

3

3.5

4

0 50 100 150 200 250 300

Time after Reflood (sec)

Elevation (m)

 
A-275 

RBHT - REFLOOD TESTS 

SUMMARY SHEET 

RUN NO: 1285

RUN CONDITIONS

Upper Plenum Pressure: 276 kPa (40 psia) 

Initial Peak Clad Temperature: 1144 degrees K (1600 degrees F) 

Rod Peak Power: 2.3 kW/m (0.7 kW/ft) 

Flooding Rate: 0.1524 m/s (6 in/s) 

Inlet Subcooling: 83 degrees K (150 degrees F) 

Start of Reflood: 115.8 s 

End of Reflood: 418.5 s 

Test Date: 7/18/2002 

Comments: No droplet data 

Heater rod surfaces below 2.54 m (100 in) quench to a 

temperature below saturation due to the high inlet 

subcooling. Therefore DATARH calculated heat transfer 

coefficients are not presented below this elevation after rod 

quench. 
A-276 

Rod_Elevation Channel Temperature Temperature Turnaround Turnaround Turnaround Quench Quench Quench 

Number at Reflood (K) at Reflood ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F)

B6_0.592m 148 777.82 940.38 9.45 805.82 990.8 25.95 675.33 755.91B6_0.744m 149 805.63 990.44 10.45 838 1048.71 30.95 686.68 776.34B6_0.846m 150 836.51 1046.02 10.95 871.23 1108.52 33.95 705.93 810.99B6_0.897m 151 848.04 1066.78 10.95 883.6 1130.79 35.95 701.38 802.79

C6_1.04m 137 897.55 1155.9 11.45 936.7 1226.37 41.95 703.33 806.31D5_1.27m 217 955.95 1261.02 12.45 1000.19 1340.65 50.95 732.96 859.64C6_1.34m 138 941.71 1235.4 11.95 987.66 1318.09 53.45 722.83 841.4D5_1.37m 218 975.46 1296.14 12.45 1022.11 1380.11 56.95 711.68 821.34C6_1.39m 139 947 1244.91 12.95 992.4 1326.64 57.45 715.61 828.41D5_1.45m 219 986.67 1316.31 12.95 1034.99 1403.29 58.45 741.62 875.23C6_1.47m 140 958.59 1265.77 11.95 1006.99 1352.89 60.95 695.89 792.92D5_1.52m 220 997.15 1335.19 13.95 1046.99 1424.9 63.45 726.71 848.38C6_1.62m 141 976.4 1297.83 16.95 1029.64 1393.66 67.45 745.49 882.2D5_1.68m 221 1015.78 1368.72 16.95 1071.85 1469.64 69.95 761.61 911.22D5_1.78m 222 999.97 1340.26 11.95 1050.55 1431.31 76.45 709.52 817.45D5_1.85m 223 1027.87 1390.48 11.95 1080.33 1484.91 79.95 686.82 776.58C6_1.87m 142 1004.53 1348.47 12.45 1059.96 1448.24 81.45 694.05 789.6D5_1.90m 224 1036.01 1405.12 11.95 1090.93 1503.98 80.95 699.39 799.21C6_1.95m 144 1014.25 1365.97 12.45 1071.42 1468.87 85.45 697.64 796.07C3_2.17m 178 1043.89 1419.32 11.45 1100.79 1521.74 101.45 678.35 761.35D4_2.24m 241 1088.94 1500.41 11.45 1143.63 1598.85 105.95 649.58 709.56D4_2.32m 242 1098.18 1517.04 11.45 1157.73 1624.22 111.45 672.08 750.06C3_2.35m 180 1088.56 1499.72 11.95 1151.25 1612.56 113.95 675.35 755.94D4_2.37m 243 1105.56 1530.32 11.95 1166.57 1640.14 115.45 676.65 758.28C3_2.40m 181 1091.48 1504.98 11.95 1154.94 1619.2 118.95 663.52 734.64D4_2.54m 245 1131.28 1576.61 11.45 1192.05 1686 131.45 678.83 762.21D6_2.62m 129 1121.02 1558.15 11.45 1183.81 1671.16 137.95 688.59 779.77D6_2.69m 130 1121.34 1558.72 11.45 1185.52 1674.25 147.95 675.32 755.88C3_2.76m 183 1120.45 1557.13 11.95 1184.63 1672.64 156.95 679.92 764.17D4_2.79m 247 1095.3 1511.86 10.45 1155.74 1620.64 160.45 688.77 780.1D6_2.87m 131 1063.49 1454.6 10.45 1121.96 1559.83 167.95 634.13 681.75D6_2.92m 132 1037.93 1408.58 11.95 1102.15 1524.18 173.95 642.68 697.13D6_2.97m 133 1009.1 1356.69 11.95 1070.17 1466.62 179.95 631.76 677.47D6_3.07m 134 972.34 1290.53 12.45 1029.17 1392.82 187.45 633.29 680.23

E3_3.12m 197 978.47 1301.55 11.95 1034.49 1402.4 193.45 615.77 648.7

D6_3.17m 135 937.94 1228.6 12.45 990.68 1323.54 195.95 628.87 672.28D6_3.27m 136 893.11 1147.91 12.45 944.36 1240.16 204.45 622.53 660.87D4_3.61m 248 681.06 766.21 12.95 736.52 866.05 165.45 482.08 408.06
A-277 
A-278 
A-279 
A-280 

Heater Rod Temperature during Reflood 

RBHT Exp. 1285

300

400

500

600

700

800

900

1000

0 50 100 150 200 250 300

Time after Reflood (sec)

Temperature (K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1285

300

400

500

600

700

800

900

1000

1100

0 50 100 150 200 250 300

Time after Reflood (sec)

Temperature (K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)
A-281 

Heater Rod Temperature during Reflood 

RBHT Exp. 1285

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300

Time after Reflood (sec)

Temperature (K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1285

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300

Time after Reflood (sec)

Temperature (K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)
A-282 

Heater Rod Temperature during Reflood 

RBHT Exp. 1285

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300

Time after Reflood (sec)

Temperature (K)

Chan. 195 2.93m (115.4in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.94m (115.7in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1285

400

500

600

700

800

900

1000

1100

0 50 100 150 200 250 300

Time after Reflood (sec)

Temperature (K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)
A-283 

Heater Rod Temperature during Reflood 

RBHT Exp. 1285

400

500

600

700

800

900

0 50 100 150 200 250 300

Time after Reflood (sec)

Temperature (K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1285

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300

Time after Reflood (sec)

Temperature (K)

Chan. 318 2.37m (93.5in)

Chan. 319 2.37m (93.5in)
A-284 

Steam Probe Temperature during Reflood 

RBHT Exp. 1285

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300

Time after Reflood (sec)

Temperature (K)

Chan. 323 2.54m (100in)

Chan. 324 2.54m (100in)

Chan. 325 2.54m (100in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1285

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300

Time after Reflood (sec)

Temperature (K)

Chan. 326 2.93m (115.4in)

Chan. 327 2.93m (115.4in)

Chan. 328 2.93m (115.4in)
A-285 

Steam Probe Temperature during Reflood 

RBHT Exp. 1285

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300

Time after Reflood (sec)

Temperature (K)

Chan. 329 3.05m (120in)

Chan. 330 3.05m (120in)

Chan. 331 3.05m (120in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1285

300

400

500

600

700

800

900

1000

0 50 100 150 200 250 300

Time after Reflood (sec)

Temperature (K)

Chan. 332 3.45m (136in)

Chan. 333 3.45m (136in)

Chan. 334 3.45m (136in)
A-286 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1285

300

400

500

600

700

800

900

1000

1100

0 50 100 150 200 250 300

Time after Reflood (sec)

Temperature (K)

Chan. 260 1.75m (69in)

Chan. 261 1.75m (69in)

Spacer Grid Temperature during Reflood 

RBHT Exp. 1285

300

400

500

600

700

800

900

1000

1100

0 50 100 150 200 250 300

Time after Reflood (sec)

Temperature (K)

Chan. 266 2.26m (89in)

Chan. 267 2.26m (89in)
A-287 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1285

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300

Time after Reflood (sec)

Temperature (K)

Chan. 272 2.79m (110in)

Chan. 273 2.79m (110in)

Chan. 275 2.79m (110in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1285

10

1000

100000

0 50 100 150 200 250 300

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)
A-288 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1285

10

1000

100000

0 50 100 150 200 250 300

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1285

10

1000

100000

0 50 100 150 200 250 300

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)
A-289 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1285

1

100

10000

1000000

0 50 100 150 200 250 300

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1285

1

100

10000

1000000

0 50 100 150 200 250 300

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 195 2.93m (115.5in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.93m (115.7in)
A-290 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1285

1

100

10000

1000000

0 50 100 150 200 250 300

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1285

1

100

10000

1000000

0 50 100 150 200 250 300

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)
A-291 

Quench Data, RBHT Exp. 1285

0

0.5

1

1.5

2

2.5

3

3.5

4

0 50 100 150 200 250

Time after Reflood (sec)

Elevation (m)
A-292 

RBHT - REFLOOD TESTS 

SUMMARY SHEET 

RUN NO: 1291

RUN CONDITIONS

Upper Plenum Pressure: 414 kPa (60 psia) 

Initial Peak Clad Temperature: 1144 degrees K (1600 degrees F) 

Rod Peak Power: 2.3 kW/m (0.7 kW/ft) 

Flooding Rate: 0.1524 m/s (6 in/s) 

Inlet Subcooling: 83 degrees K (150 degrees F) 

Start of Reflood: 122.9 s 

End of Reflood: 366.6 s 

Test Date: 7/19/2002 

Comments: No droplet data 

Heater rod surfaces below 2.54 m (100 in) quench to a 

temperature below saturation due to the high inlet 

subcooling. Therefore DATARH calculated heat transfer 

coefficients are not presented below this elevation after rod 

quench. 
A-293 

Rod_Elevation Channel Temperature Temperature Turnaround Turnaround Turnaround Quench Quench Quench 

Number at Reflood (K) at Reflood ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F)

B6_0.592m 148 785.7 954.57 15.35 836.5 1046.01 37.85 678.91 762.35B6_0.744m 149 823.47 1022.57 16.35 875.58 1116.36 43.35 674.31 754.07B6_0.846m 150 851.55 1073.11 16.35 906.96 1172.83 47.35 688.13 778.94B6_0.897m 151 861.61 1091.22 16.35 918.48 1193.57 49.85 675.67 756.51

C6_1.04m 137 901.29 1162.64 16.85 963.08 1273.86 55.35 680.38 764.99D5_1.27m 217 966.44 1279.91 16.35 1032.63 1399.05 63.85 688.34 779.32C6_1.34m 138 960.15 1268.58 16.85 1029.15 1392.77 64.35 716.67 830.32D5_1.37m 218 987.96 1318.64 16.85 1057.88 1444.49 69.35 681.26 766.58C6_1.39m 139 964.86 1277.05 16.85 1034.54 1402.49 69.35 694.19 789.85D5_1.45m 219 999.31 1339.07 16.85 1071.17 1468.42 72.35 678.56 761.72C6_1.47m 140 974.98 1295.28 16.85 1046.24 1423.55 72.35 681.62 767.22D5_1.52m 220 1008.8 1356.14 17.35 1082.52 1488.84 75.35 688.46 779.54C6_1.62m 141 990.25 1322.77 17.35 1066.17 1459.41 79.35 696.17 793.42D5_1.68m 221 1022.5 1380.81 17.35 1101.08 1522.25 82.85 685.51 774.23D5_1.78m 222 992.07 1326.04 16.85 1067.01 1460.92 87.85 667.22 741.3D5_1.85m 223 1041.77 1415.49 16.35 1119.47 1555.36 91.35 636.41 685.84C6_1.87m 142 1025.47 1386.16 16.85 1105.47 1530.16 91.35 663.49 734.59D5_1.90m 224 1052.66 1435.09 16.85 1133.56 1580.71 89.35 676.34 757.72C6_1.95m 144 1036.61 1406.22 16.85 1119.18 1554.83 93.85 684.84 773.02C3_2.17m 178 1047.06 1425.02 16.85 1134.7 1582.77 110.85 648.75 708.06D4_2.24m 241 1106.66 1532.29 16.35 1190.84 1683.82 113.35 630.47 675.16D4_2.32m 242 1118.63 1553.84 16.85 1208.25 1715.16 118.85 649.73 709.83C3_2.35m 180 1112.51 1542.83 16.85 1205.69 1710.56 120.35 650.04 710.39D4_2.37m 243 1124.22 1563.9 16.85 1215.84 1728.83 121.35 653.23 716.13C3_2.40m 181 1113.48 1544.57 16.85 1207.51 1713.83 124.35 655.96 721.04D4_2.54m 245 1142.77 1597.3 16.35 1234.42 1762.27 136.35 652.75 715.26D6_2.62m 129 1129.04 1572.58 16.35 1224.1 1743.68 141.85 674.54 754.48D6_2.69m 130 1121.03 1558.16 16.35 1217.67 1732.12 149.35 683.67 770.92C3_2.76m 183 1109.04 1536.59 16.35 1204.9 1709.14 155.85 683.51 770.63D6_2.92m 132 1022.77 1381.29 16.85 1113.35 1544.34 169.35 634.79 682.94D6_2.97m 133 998.9 1338.33 17.35 1084.12 1491.72 173.35 615.64 648.46D6_3.07m 134 963.19 1274.05 17.35 1041.61 1415.21 177.85 630.13 674.55

E3_3.12m 197 954.41 1258.26 17.35 1034.65 1402.68 182.35 618.33 653.31

D6_3.17m 135 922.01 1199.93 17.35 995.42 1332.07 184.35 629.63 673.64D6_3.27m 136 852.24 1074.35 17.85 925.98 1207.07 190.35 623.6 662.79D4_3.61m 248 633.25 680.16 17.85 722.66 841.09 148.85 498.61 437.81
A-294 
A-295 
A-296 
A-297 

Heater Rod Temperature during Reflood 

RBHT Exp. 1291

300

400

500

600

700

800

900

1000

0 50 100 150 200 250

Time after Reflood (sec)

Temperature (K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1291

300

400

500

600

700

800

900

1000

1100

0 50 100 150 200 250

Time after Reflood (sec)

Temperature (K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)
A-298 

Heater Rod Temperature during Reflood 

RBHT Exp. 1291

400

500

600

700

800

900

1000

1100

1200

1300

0 50 100 150 200 250

Time after Reflood (sec)

Temperature (K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1291

400

500

600

700

800

900

1000

1100

1200

1300

0 50 100 150 200 250

Time after Reflood (sec)

Temperature (K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)
A-299 

Heater Rod Temperature during Reflood 

RBHT Exp. 1291

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250

Time after Reflood (sec)

Temperature (K)

Chan. 195 2.93m (115.4in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.94m (115.7in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1291

400

500

600

700

800

900

1000

1100

0 50 100 150 200 250

Time after Reflood (sec)

Temperature (K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)
A-300 

Heater Rod Temperature during Reflood 

RBHT Exp. 1291

400

500

600

700

800

900

0 50 100 150 200 250

Time after Reflood (sec)

Temperature (K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1291

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250

Time after Reflood (sec)

Temperature (K)

Chan. 318 2.37m (93.5in)

Chan. 319 2.37m (93.5in)
A-301 

Steam Probe Temperature during Reflood 

RBHT Exp. 1291

300

400

500

600

700

800

900

1000

1100

1200

1300

0 50 100 150 200 250

Time after Reflood (sec)

Temperature (K)

Chan. 323 2.54m (100in)

Chan. 324 2.54m (100in)

Chan. 325 2.54m (100in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1291

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250

Time after Reflood (sec)

Temperature (K)

Chan. 326 2.93m (115.4in)

Chan. 327 2.93m (115.4in)

Chan. 328 2.93m (115.4in)
A-302 

Steam Probe Temperature during Reflood 

RBHT Exp. 1291

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250

Time after Reflood (sec)

Temperature (K)

Chan. 329 3.05m (120in)

Chan. 330 3.05m (120in)

Chan. 331 3.05m (120in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1291

400

500

600

700

800

900

1000

0 50 100 150 200 250

Time after Reflood (sec)

Temperature (K)

Chan. 332 3.45m (136in)

Chan. 333 3.45m (136in)

Chan. 334 3.45m (136in)
A-303 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1291

300

400

500

600

700

800

900

1000

1100

0 50 100 150 200 250

Time after Reflood (sec)

Temperature (K)

Chan. 260 1.75m (69in)

Chan. 261 1.75m (69in)

Spacer Grid Temperature during Reflood 

RBHT Exp. 1291

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250

Time after Reflood (sec)

Temperature (K)

Chan. 266 2.26m (89in)

Chan. 267 2.26m (89in)
A-304 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1291

300

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250

Time after Reflood (sec)

Temperature (K)

Chan. 272 2.79m (110in)

Chan. 273 2.79m (110in)

Chan. 275 2.79m (110in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1291

10

1000

100000

10000000

0 50 100 150 200 250

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)
A-305 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1291

10

1000

100000

0 50 100 150 200 250

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1291

10

1000

100000

10000000

0 50 100 150 200 250

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)
A-306 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1291

1

100

10000

1000000

0 50 100 150 200 250

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1291

1

100

10000

1000000

0 50 100 150 200 250

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 195 2.93m (115.5in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.93m (115.7in)
A-307 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1291

1

100

10000

1000000

0 50 100 150 200 250

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1291

1

100

10000

1000000

0 50 100 150 200 250

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)
A-308 

Quench Data, RBHT Exp. 1291

0

0.5

1

1.5

2

2.5

3

3.5

4

0 50 100 150 200 250

Time after Reflood (sec)

Elevation (m)
A-309 

RBHT - REFLOOD TESTS 

SUMMARY SHEET 

RUN NO: 1295

RUN CONDITIONS

Upper Plenum Pressure: 414 kPa (60 psia) 

Initial Peak Clad Temperature: 1144 degrees K (1600 degrees F) 

Rod Peak Power: 2.3 kW/m (0.7 kW/ft) 

Flooding Rate: 0.1524 m/s (6 in/s) 

Inlet Subcooling: 23 degrees K (42 degrees F) 

Start of Reflood: 114 s 

End of Reflood: 451.2 s 

Test Date: 7/23/2002 

Comments: No droplet data 
A-310 

 

Rod_Elevation Channel Temperature Temperature Turnaround Turnaround Turnaround Quench Quench Quench 

Number at Reflood (K) at Reflood ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F)

B6_0.592m 148 809.25 996.96 6.25 829.4 1033.22 41.25 612.56 642.92B6_0.744m 149 834.26 1041.98 6.75 855.64 1080.47 51.75 598.09 616.88B6_0.846m 150 863.18 1094.03 7.25 887.04 1136.98 57.75 607.06 633.01B6_0.897m 151 874.56 1114.52 7.25 899.25 1158.96 60.75 610.94 640.01

C6_1.04m 137 919.91 1196.15 7.75 946.85 1244.64 69.75 642.26 696.38D5_1.27m 217 970.47 1287.16 7.75 999.2 1338.88 86.25 630.74 675.64C6_1.34m 138 969.06 1284.62 7.75 1000.04 1340.38 89.75 642.17 696.22D5_1.37m 218 995.3 1331.86 7.75 1026.46 1387.93 94.25 647.3 705.45C6_1.39m 139 976.18 1297.43 7.75 1007.58 1353.96 93.75 648.27 707.2D5_1.45m 219 1010.43 1359.09 7.75 1042.58 1416.96 99.75 654.75 718.87C6_1.47m 140 991.28 1324.61 7.75 1023.64 1382.86 99.75 651.3 712.66D5_1.52m 220 1024.48 1384.38 7.75 1057.6 1443.98 106.75 660.28 728.81C6_1.62m 141 1015.54 1368.28 8.25 1050.41 1431.06 112.75 672.28 750.41D5_1.68m 221 1048.62 1427.84 8.25 1084.16 1491.8 121.25 676.55 758.1D5_1.78m 222 993.09 1327.87 7.75 1031.57 1397.14 130.75 662.7 733.17D5_1.85m 223 1056.44 1441.91 7.75 1091.04 1504.19 136.75 635.33 683.9C6_1.87m 142 1046.89 1424.72 8.25 1082.67 1489.12 135.75 644.57 700.53D5_1.90m 224 1072.85 1471.44 7.75 1109.48 1537.37 140.75 649.2 708.87C6_1.95m 144 1063.96 1455.43 8.25 1101.23 1522.53 141.25 670.66 747.5C3_2.17m 178 1076.16 1477.39 7.75 1118.57 1553.75 163.25 686.62 776.23D4_2.24m 241 1137.5 1587.82 7.75 1174.5 1654.42 175.25 648.09 706.88D4_2.32m 242 1159.62 1627.64 7.75 1200.25 1700.76 182.25 687.17 777.21C3_2.35m 180 1155.73 1620.63 8.25 1198.51 1697.63 178.75 703.22 806.11D4_2.37m 243 1167.15 1641.18 7.75 1209.44 1717.3 187.75 700.7 801.57C3_2.40m 181 1158.51 1625.63 8.25 1202.08 1704.06 184.25 714.66 826.71D4_2.54m 245 1198.03 1696.77 7.25 1238 1768.71 210.75 711.66 821.3D6_2.62m 129 1198.33 1697.3 7.25 1238.71 1770 213.75 723.89 843.32D6_2.69m 130 1199.15 1698.79 7.25 1240.15 1772.57 223.25 732.41 858.64C3_2.76m 183 1178.26 1661.18 7.75 1220.53 1737.26 230.25 745.05 881.41D6_2.92m 132 1094.55 1510.5 8.25 1137.55 1587.91 247.75 679.23 762.92D6_2.97m 133 1064.75 1456.87 8.25 1105.79 1530.74 252.75 666.8 740.55D6_3.07m 134 1023.74 1383.04 8.25 1061.84 1451.63 258.75 662.99 733.69

E3_3.12m 197 1024.17 1383.82 8.25 1063.18 1454.04 268.25 661.54 731.09

D6_3.17m 135 982.14 1308.16 8.25 1017.97 1372.67 265.75 660.67 729.51D6_3.27m 136 924.45 1204.32 8.75 960.9 1269.93 272.25 622.49 660.79D4_3.61m 248 694.59 790.58 8.25 747.45 885.72 334.75 422.11 300.11
A-311 
A-312 
A-313 
A-314 

Heater Rod Temperature during Reflood 

RBHT Exp. 1295

400

500

600

700

800

900

1000

0 50 100 150 200 250 300 350

Time after Reflood (sec)

Temperature (K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1295

400

500

600

700

800

900

1000

1100

0 50 100 150 200 250 300 350

Time after Reflood (sec)

Temperature (K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)
A-315 

Heater Rod Temperature during Reflood 

RBHT Exp. 1295

400

500

600

700

800

900

1000

1100

1200

1300

0 50 100 150 200 250 300 350

Time after Reflood (sec)

Temperature (K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1295

400

500

600

700

800

900

1000

1100

1200

1300

0 50 100 150 200 250 300 350

Time after Reflood (sec)

Temperature (K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)
A-316 

Heater Rod Temperature during Reflood 

RBHT Exp. 1295

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350

Time after Reflood (sec)

Temperature (K)

Chan. 195 2.93m (115.4in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.94m (115.7in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1295

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350

Time after Reflood (sec)

Temperature (K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)
A-317 

Heater Rod Temperature during Reflood 

RBHT Exp. 1295

400

500

600

700

800

900

0 50 100 150 200 250 300 350

Time after Reflood (sec)

Temperature (K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1295

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350

Time after Reflood (sec)

Temperature (K)

Chan. 318 2.37m (93.5in)

Chan. 319 2.37m (93.5in)
A-318 

Steam Probe Temperature during Reflood 

RBHT Exp. 1295

400

500

600

700

800

900

1000

1100

1200

1300

0 50 100 150 200 250 300 350

Time after Reflood (sec)

Temperature (K)

Chan. 323 2.54m (100in)

Chan. 324 2.54m (100in)

Chan. 325 2.54m (100in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1295

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350

Time after Reflood (sec)

Temperature (K)

Chan. 326 2.93m (115.4in)

Chan. 327 2.93m (115.4in)

Chan. 328 2.93m (115.4in)
A-319 

Steam Probe Temperature during Reflood 

RBHT Exp. 1295

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350

Time after Reflood (sec)

Temperature (K)

Chan. 329 3.05m (120in)

Chan. 330 3.05m (120in)

Chan. 331 3.05m (120in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1295

400

500

600

700

800

900

1000

0 50 100 150 200 250 300 350

Time after Reflood (sec)

Temperature (K)

Chan. 332 3.45m (136in)

Chan. 333 3.45m (136in)

Chan. 334 3.45m (136in)
A-320 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1295

400

500

600

700

800

900

1000

1100

0 50 100 150 200 250 300 350

Time after Reflood (sec)

Temperature (K)

Chan. 260 1.75m (69in)

Chan. 261 1.75m (69in)

Spacer Grid Temperature during Reflood 

RBHT Exp. 1295

400

500

600

700

800

900

1000

1100

0 50 100 150 200 250 300 350

Time after Reflood (sec)

Temperature (K)

Chan. 266 2.26m (89in)

Chan. 267 2.26m (89in)
A-321 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1295

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350

Time after Reflood (sec)

Temperature (K)

Chan. 272 2.79m (110in)

Chan. 273 2.79m (110in)

Chan. 275 2.79m (110in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1295

10

1000

100000

0 50 100 150 200 250 300 350

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)
A-322 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1295

10

1000

100000

0 50 100 150 200 250 300 350

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1295

10

1000

100000

0 50 100 150 200 250 300 350

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)
A-323 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1295

1

100

10000

1000000

0 50 100 150 200 250 300 350

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1295

1

100

10000

1000000

0 50 100 150 200 250 300 350

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 195 2.93m (115.5in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.93m (115.7in)
A-324 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1295

1

100

10000

1000000

0 50 100 150 200 250 300 350

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1295

1

100

10000

1000000

0 50 100 150 200 250 300 350

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)
A-325 

Quench Data, RBHT Exp. 1295

0

0.5

1

1.5

2

2.5

3

3.5

4

0 50 100 150 200 250 300 350

Time after Reflood (sec)

Elevation (m)
A-326 

RBHT - REFLOOD TESTS 

SUMMARY SHEET 

RUN NO: 1300

RUN CONDITIONS

Upper Plenum Pressure: 276 kPa (40 psia) 

Initial Peak Clad Temperature: 1144 degrees K (1600 degrees F) 

Rod Peak Power: 2.3 kW/m (0.7 kW/ft) 

Flooding Rate: 0.0762 m/s (3 in/s) 

Inlet Subcooling: 76 degrees K (136 degrees F) 

Start of Reflood: 141.2 s 

End of Reflood: 727.5 s 

Test Date: 7/23/2002 

 

Comments: No Droplet Data 

 Heater rod surfaces below 1m (40 in) quench to a 

temperature below saturation due to the high inlet 

subcooling. Therefore DATARH calculated heat transfer 

coefficients are not presented below this elevation after rod 

quench. 
A-327 

Rod_Elevation Channel Temperature Temperature Turnaround Turnaround Turnaround Quench Quench Quench 

Number at Reflood (K) at Reflood ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F)

B6_0.592m 148 779.38 943.19 13.05 822.85 1021.44 39.55 665.26 737.78B6_0.744m 149 801.72 983.4 13.55 849.13 1068.75 50.55 653.82 717.18B6_0.846m 150 830.76 1035.68 13.55 880.7 1125.58 59.55 637.89 688.52B6_0.897m 151 841.84 1055.63 14.05 893.42 1148.48 63.55 640.86 693.86

C6_1.04m 137 891.56 1145.12 15.05 946.99 1244.89 76.55 655.6 720.4D5_1.27m 217 951.72 1253.4 15.05 1011.31 1360.68 99.05 667.09 741.08C6_1.34m 138 940.16 1232.61 15.55 1003.46 1346.54 106.55 658.37 725.38D5_1.37m 218 972.66 1291.11 15.55 1036.02 1405.15 110.55 678.01 760.74C6_1.39m 139 945.89 1242.92 16.05 1009.63 1357.64 112.55 667.31 741.47D5_1.45m 219 985.04 1313.39 15.55 1049.91 1430.15 119.05 681.68 767.33C6_1.47m 140 958.01 1264.73 15.55 1023.42 1382.47 121.55 676.47 757.95D5_1.52m 220 996.14 1333.37 15.55 1063.11 1453.92 129.55 682.52 768.85C6_1.62m 141 975.97 1297.06 27.05 1046.85 1424.65 142.05 686.95 776.82D5_1.68m 221 1015.74 1368.64 32.05 1088.58 1499.76 151.05 691.19 784.45D5_1.78m 222 1000.91 1341.94 14.55 1067 1460.91 166.05 712.54 822.88D5_1.85m 223 1029.02 1392.55 14.55 1099.84 1520.02 177.05 676.86 758.66C6_1.87m 142 1006.58 1352.15 15.05 1079.46 1483.34 180.05 686.09 775.27D5_1.90m 224 1037.45 1407.73 15.05 1110.74 1539.64 160.55 758.66 905.89C6_1.95m 144 1017.76 1372.28 15.05 1092.2 1506.27 191.55 704.02 807.55C3_2.17m 178 1046.59 1424.18 14.55 1122.02 1559.95 231.05 743.13 877.94D4_2.24m 241 1096.88 1514.7 14.05 1172.11 1650.11 255.05 697.8 796.36D4_2.32m 242 1105.58 1530.36 14.55 1185.28 1673.81 270.05 733.12 859.92C3_2.35m 180 1097.46 1515.74 15.05 1181.17 1666.42 264.05 773.34 932.32D4_2.37m 243 1112.85 1543.45 14.55 1194.05 1689.61 281.55 740.91 873.94C3_2.40m 181 1100.04 1520.39 15.05 1184.12 1671.73 275.55 775.81 936.76D4_2.54m 245 1137.43 1587.69 14.05 1218.87 1734.27 331.05 745.48 882.17D6_2.62m 129 1126.36 1567.76 14.05 1210.47 1719.16 337.05 784.47 952.36D6_2.69m 130 1125.98 1567.08 14.05 1211.36 1720.76 359.55 794.27 970C3_2.76m 183 1124.27 1564 14.55 1208.89 1716.31 377.55 810.77 999.7D4_2.79m 247 1096.02 1513.15 13.55 1173.45 1652.53 408.05 718.97 834.45D6_2.87m 131 1067.07 1461.03 13.55 1144.87 1601.07 406.55 734.38 862.19D6_2.92m 132 1039.57 1411.54 15.05 1121.73 1559.43 418.05 752.87 895.49D6_2.97m 133 1008.46 1355.54 15.05 1086.09 1495.28 431.55 749.42 889.27D6_3.07m 134 971.61 1289.21 15.05 1042.84 1417.43 449.55 749.69 889.76

E3_3.12m 197 975.87 1296.88 15.05 1046.37 1423.78 478.05 716.19 829.46

D6_3.17m 135 938.75 1230.06 15.05 1004.53 1348.47 470.05 734.47 862.36D6_3.27m 136 893.4 1148.44 15.55 957.05 1263 489.05 725.67 846.52D4_3.61m 248 678.33 761.31 15.55 753.04 895.79 547.05 580.89 585.92
A-328 
A-329 
A-330 
A-331 

Heater Rod Temperature during Reflood 

RBHT Exp. 1300

300

400

500

600

700

800

900

1000

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1300

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)
A-332 

Heater Rod Temperature during Reflood 

RBHT Exp. 1300

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1300

400

500

600

700

800

900

1000

1100

1200

1300

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)
A-333 

Heater Rod Temperature during Reflood 

RBHT Exp. 1300

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 195 2.93m (115.4in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.94m (115.7in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1300

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)
A-334 

Heater Rod Temperature during Reflood 

RBHT Exp. 1300

400

500

600

700

800

900

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1300

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 318 2.37m (93.5in)

Chan. 319 2.37m (93.5in)
A-335 

Steam Probe Temperature during Reflood 

RBHT Exp. 1300

400

500

600

700

800

900

1000

1100

1200

1300

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 323 2.54m (100in)

Chan. 324 2.54m (100in)

Chan. 325 2.54m (100in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1300

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 326 2.93m (115.4in)

Chan. 327 2.93m (115.4in)

Chan. 328 2.93m (115.4in)
A-336 

Steam Probe Temperature during Reflood 

RBHT Exp. 1300

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 329 3.05m (120in)

Chan. 330 3.05m (120in)

Chan. 331 3.05m (120in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1300

400

500

600

700

800

900

1000

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 332 3.45m (136in)

Chan. 333 3.45m (136in)

Chan. 334 3.45m (136in)
A-337 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1300

300

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 260 1.75m (69in)

Chan. 261 1.75m (69in)

Spacer Grid Temperature during Reflood 

RBHT Exp. 1300

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 266 2.26m (89in)

Chan. 267 2.26m (89in)
A-338 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1300

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 272 2.79m (110in)

Chan. 273 2.79m (110in)

Chan. 275 2.79m (110in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1300

10

1000

100000

0 100 200 300 400 500 600

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)
A-339 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1300

10

1000

100000

0 100 200 300 400 500 600

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1300

10

1000

100000

0 100 200 300 400 500 600

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 203 2.37m (93.2in)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)
A-340 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1300

1

100

10000

1000000

0 100 200 300 400 500 600

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1300

1

100

10000

1000000

0 100 200 300 400 500 600

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 195 2.93m (115.5in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.93m (115.7in)
A-341 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1300

1

100

10000

1000000

0 100 200 300 400 500 600

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1300

1

100

10000

1000000

0 100 200 300 400 500 600

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)
A-342 

Quench Data, RBHT Exp. 1300

0

0.5

1

1.5

2

2.5

3

3.5

4

0 100 200 300 400 500 600

Time after Reflood (sec)

Elevation (m)

 
A-343 

RBHT - REFLOOD TESTS 

SUMMARY SHEET 

RUN NO: 1310

RUN CONDITIONS

Upper Plenum Pressure: 138 kPa (20 psia) 

Initial Peak Clad Temperature: 1033 degrees K (1400 degrees F) 

Rod Peak Power: 1.31 kW/m (0.4 kW/ft) 

Flooding Rate: 0.0254 m/s (1 in/s) 

Inlet Subcooling: 11 degrees K (20 degrees F) 

Start of Reflood: 185 s 

End of Reflood: 785 s 

Test Date: 8/1/2002 

Comments: Power turn off at 449.7 seconds. Inlet flow continued until 

entire bundle quenched. 

 DATARH heat transfer coefficients calculated until power 

was turned off. 

 Droplet data was collected until approximately 60 seconds 

after power was turn off. 

 
A-344 

Rod_Elevation Channel Temperature Temperature Turnaround Turnaround Turnaround Quench Quench Quench 

Number at Reflood (K) at Reflood ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F)

B6_0.592m 148 740.02 872.35 14.25 766.12 919.32 98.75 574.9 575.13B6_0.744m 149 765.23 917.72 15.25 794.11 969.7 135.25 559.08 546.66B6_0.846m 150 786.03 955.17 15.75 817.39 1011.61 161.25 587.47 597.75B6_0.897m 151 794.09 969.67 18.75 826.77 1028.49 179.75 597.05 615.01

C6_1.04m 137 838.52 1049.65 63.25 881.71 1127.38 237.25 564.8 556.96D5_1.27m 217 896.12 1153.33 47.25 945.76 1242.69 301.75 600.59 621.37C6_1.34m 138 878.04 1120.78 74.75 940.68 1233.54 317.75 579.98 584.28D5_1.37m 218 910.69 1179.56 74.75 980.89 1305.91 321.25 602.67 625.11C6_1.39m 139 882.16 1128.2 118.25 962.42 1272.66 326.25 587.87 598.49D5_1.45m 219 919.6 1195.6 117.75 1009.5 1357.42 334.25 589.84 602.03C6_1.47m 140 891.1 1144.29 146.75 993.13 1327.95 339.75 586.15 595.38D5_1.52m 220 927.5 1209.81 150.75 1046.06 1423.21 348.25 590.66 603.5C6_1.62m 141 901.29 1162.64 226.75 1063.29 1454.23 367.25 573.74 573.05D5_1.68m 221 935.25 1223.76 227.75 1121.18 1558.44 376.75 575.65 576.48D5_1.78m 222 926.16 1207.39 227.75 1073.13 1471.94 393.75 560.96 550.04D5_1.85m 223 945.82 1242.79 185.75 1092.91 1507.55 398.25 534.73 502.83C6_1.87m 142 917.57 1191.94 149.25 1060.97 1450.06 396.75 553.27 536.2D5_1.90m 224 952.69 1255.16 227.75 1124.74 1564.85 402.25 561.6 551.19C6_1.95m 144 931.53 1217.06 227.75 1102.44 1524.71 406.25 577.99 580.7C3_2.17m 178 971.53 1289.06 264.75 1148.01 1606.72 446.75 558.5 545.62D4_2.24m 241 1015.21 1367.7 264.75 1145.8 1602.76 444.75 521.91 479.75D4_2.32m 242 1023.52 1382.66 264.75 1183.81 1671.16 451.25 566.92 560.77C3_2.35m 180 1013.96 1365.44 264.75 1186.67 1676.32 456.75 551.37 532.77D4_2.37m 243 1029.23 1392.93 264.75 1195.43 1692.09 460.25 555.82 540.79C3_2.40m 181 1016.53 1370.07 264.75 1188.14 1678.97 464.75 555.92 540.97D4_2.54m 245 1049.99 1430.29 265.25 1265.79 1818.73 488.75 546.25 523.56D6_2.62m 129 1035.71 1404.59 265.25 1261.81 1811.57 494.25 555.26 539.78D6_2.69m 130 1036.53 1406.07 265.25 1279.06 1842.62 504.25 561.61 551.22C3_2.76m 183 1036.61 1406.2 265.25 1288.44 1859.5 515.75 557.88 544.5D4_2.79m 247 1025.71 1386.59 286.25 1211.09 1720.27 513.25 499 438.51D6_2.87m 131 998 1336.72 265.25 1083.9 1491.32 510.25 500.9 441.94D6_2.92m 132 975.72 1296.61 265.25 1095.8 1512.75 513.25 535.31 503.87D6_2.97m 133 947.16 1245.19 264.75 1094.89 1511.11 520.25 544.13 519.75D6_3.07m 134 909.85 1178.04 264.75 1091.34 1504.72 527.75 551.57 533.14

E3_3.12m 197 908.67 1175.91 264.75 1099.62 1519.64 538.25 526.54 488.08

D6_3.17m 135 875.08 1115.45 264.75 1080.92 1485.97 538.75 543.65 518.89D6_3.27m 136 835.23 1043.72 264.75 1057.54 1443.89 549.25 536.33 505.7
A-345 
A-346 
A-347 
A-348 

Heater Rod Temperature during Reflood 

RBHT Exp. 1310

300

400

500

600

700

800

900

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)

Power Turned Off

Heater Rod Temperature during Reflood 

RBHT Exp. 1310

300

400

500

600

700

800

900

1000

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)

Power Turned Off
A-349 

Heater Rod Temperature during Reflood 

RBHT Exp. 1310

300

500

700

900

1100

1300

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)

Power Turned Off

Heater Rod Temperature during Reflood 

RBHT Exp. 1310

300

500

700

900

1100

1300

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)

Power Turned Off
A-350 

Heater Rod Temperature during Reflood 

RBHT Exp. 1310

300

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 195 2.93m (115.4in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.94m (115.7in)

Power Turned Off

Heater Rod Temperature during Reflood 

RBHT Exp. 1310

300

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)

Power Turned Off
A-351 

Heater Rod Temperature during Reflood 

RBHT Exp. 1310

300

400

500

600

700

800

900

1000

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)

Power Turned Off

Steam Probe Temperature during Reflood 

RBHT Exp. 1310

300

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 318 2.37m (93.5in)

Chan. 319 2.37m (93.5in)

Power Turned Off
A-352 

Steam Probe Temperature during Reflood 

RBHT Exp. 1310

300

500

700

900

1100

1300

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 323 2.54m (100in)

Chan. 324 2.54m (100in)

Chan. 325 2.54m (100in)

Power Turned Off

Steam Probe Temperature during Reflood 

RBHT Exp. 1310

300

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 326 2.93m (115.4in)

Chan. 327 2.93m (115.4in)

Chan. 328 2.93m (115.4in)

Power Turned Off
A-353 

Steam Probe Temperature during Reflood 

RBHT Exp. 1310

300

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 329 3.05m (120in)

Chan. 330 3.05m (120in)

Chan. 331 3.05m (120in)

Power Turned Off

Steam Probe Temperature during Reflood 

RBHT Exp. 1310

300

400

500

600

700

800

900

1000

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 332 3.45m (136in)

Chan. 333 3.45m (136in)

Chan. 334 3.45m (136in)

Power Turned Off
A-354 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1310

300

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 260 1.75m (69in)

Chan. 261 1.75m (69in)

Power Turned Off

Spacer Grid Temperature during Reflood 

RBHT Exp. 1310

300

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 266 2.26m (89in)

Chan. 267 2.26m (89in)

Power Turned Off
A-355 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1310

300

500

700

900

1100

1300

0 100 200 300 400 500 600

Time after Reflood (sec)

Temperature (K)

Chan. 272 2.79m (110in)

Chan. 273 2.79m (110in)

Chan. 275 2.79m (110in)

Power Turned Off

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1310

10

1000

100000

0 50 100 150 200 250 300

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)
A-356 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1310

10

1000

100000

0 50 100 150 200 250 300

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1310

10

1000

100000

0 50 100 150 200 250 300

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)
A-357 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1310

1

100

10000

1000000

0 50 100 150 200 250 300

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1310

1

100

10000

1000000

0 50 100 150 200 250 300

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 195 2.93m (115.5in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.93m (115.7in)
A-358 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1310

1

100

10000

1000000

0 50 100 150 200 250 300

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1310

1

100

10000

1000000

0 50 100 150 200 250 300

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)
A-359 

Quench Data, RBHT Exp. 1310

0

0.5

1

1.5

2

2.5

3

3.5

4

0 100 200 300 400 500 600

Time after Reflood (sec)

Elevation (m)

Power Turned Off
A-360 
A-361 
A-362 
A-363 

RBHT - REFLOOD TESTS 

SUMMARY SHEET 

RUN NO: 1319

RUN CONDITIONS

Upper Plenum Pressure: 276 kPa (40 psia) 

Initial Peak Clad Temperature: 1033 degrees K (1400 degrees F) 

Rod Peak Power: 1.31 kW/m (0.4 kW/ft) 

Flooding Rate: 0.0254 m/s (1 in/s) 

Inlet Subcooling: 11 degrees K (20 degrees F) 

Start of Reflood: 844.7 s 

End of Reflood: 1289 s 

Test Date: 8/5/2002 

Comments: Power turn off at 1010.5 seconds. Inlet flow continued 

until entire bundle quenched. 

 DATARH heat transfer coefficients calculated until power 

was turned off. 

 Droplet data was collected until approximately 30 seconds 

after power was turn off. 
A-364 

 Rod_Elevation Channel Temperature Temperature Turnaround Turnaround Turnaround Quench Quench Quench Number at Reflood (K) at Reflood ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F) B6_0.592m 148 707.99 814.7 17.05 737.95 868.62 64.05 595.83 612.81 B6_0.744m 149 732.86 859.46 19.05 767.75 922.26 82.05 573.93 573.39 B6_0.846m 150 759.02 906.55 19.55 797.63 976.05 93.05 606.62 632.23 B6_0.897m 151 768.99 924.49 19.55 809.09 996.67 99.55 616 649.11 C6_1.04m 137 810.79 999.74 21.55 855.75 1080.67 117.55 670.46 747.15 C6_1.34m 138 850.3 1070.86 51.05 909.99 1178.3 186.55 669.57 745.53 C6_1.39m 139 857.35 1083.54 65.55 924.53 1204.46 194.05 666.83 740.6 C6_1.47m 140 868.82 1104.19 71.05 945.88 1242.9 204.55 651.71 713.4 C6_1.62m 141 882.36 1128.56 93.55 995.44 1332.11 223.55 642.22 696.31 C6_1.87m 142 905.52 1170.25 94.05 1015.9 1368.94 246.55 595.34 611.93 C6_1.95m 144 924.97 1205.26 115.55 1051.3 1432.66 253.05 607.14 633.17 D6_2.62m 129 1051.42 1432.86 166.55 1254.2 1797.88 322.55 606.11 631.31 D6_2.69m 130 1050.78 1431.71 166.55 1271.97 1829.86 330.55 614.28 646.01 D6_2.87m 131 987.87 1318.47 167.05 1158.86 1626.27 346.05 543.81 519.17 D6_2.92m 132 967.55 1281.9 168.55 1168.29 1643.24 349.05 583.68 590.94 D6_2.97m 133 943.16 1238 168.55 1163.39 1634.41 354.55 596.07 613.24 D6_3.07m 134 912.69 1183.15 167.05 1154.28 1618.01 362.05 610.52 639.25 D6_3.17m 135 881.32 1126.7 167.55 1137.44 1587.71 372.05 601.84 623.62 D6_3.27m 136 832.83 1039.4 168.05 1115.77 1548.69 381.55 603.03 625.77 D5_1.27m 217 858.15 1084.98 37.05 913.76 1185.08 163.05 592.27 606.4 D5_1.37m 218 878.63 1121.84 51.05 943.64 1238.87 190.05 688.7 779.98 D5_1.45m 219 890.67 1143.51 66.05 964.88 1277.1 200.55 670.37 746.97 D5_1.52m 220 900.32 1160.89 93.05 986.5 1316.01 211.05 655 719.31 D5_1.68m 221 912.85 1183.44 115.05 1039.55 1411.49 230.05 647.56 705.92 D5_1.78m 222 897.16 1155.2 96.05 1002.97 1345.65 241.05 598.66 617.89 D5_1.85m 223 924.27 1203.99 94.55 1033.77 1401.1 245.05 579.47 583.36 D5_1.90m 224 934.93 1223.18 96.05 1061.18 1450.44 248.05 610.06 638.42 D4_2.24m 241 1014.66 1366.69 140.55 1131.24 1576.55 287.55 552.25 534.36 D4_2.32m 242 1026.14 1387.36 166.05 1182.63 1669.04 292.55 593.26 608.18

D4_2.37m 243 1033.27 1400.2 166.55 1203.98 1707.47 297.55 598.5 617.62D4_2.54m 245 1058.23 1445.12 166.55 1275.33 1835.9 321.05 593.62 608.82D4_2.79m 247 1015.57 1368.33 184.55 1251.72 1793.4 348.05 573.75 573.06D4_3.61m 248 616.68 650.33 167.05 986.57 1316.13 399.55 571.87 569.67C3_2.17m 178 967.27 1281.4 141.05 1108.56 1535.72 279.55 618.01 652.73

E3_3.12m 197 913.71 1185 167.55 1179.92 1664.18 371.05 587.11 597.12

C3_2.35m 180 1021.24 1378.54 166.55 1182.79 1669.33 292.05 616.35 649.75C3_2.40m 181 1025 1385.31 166.55 1191.19 1684.45 297.55 628.46 671.55C3_2.76m 183 1045.52 1422.26 166.55 1296.29 1873.64 340.55 625.55 666.31
A-365 
A-366 
A-367 
A-368 

Heater Rod Temperature during Reflood 

RBHT Exp. 1319

300

400

500

600

700

800

900

0 50 100 150 200 250 300 350 400 450

Time after Reflood (sec)

Temperature (K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)

Power Turned Off

Heater Rod Temperature during Reflood 

RBHT Exp. 1319

300

400

500

600

700

800

900

1000

0 50 100 150 200 250 300 350 400 450

Time after Reflood (sec)

Temperature (K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)

Power Turned Off
A-369 

Heater Rod Temperature during Reflood 

RBHT Exp. 1319

400

500

600

700

800

900

1000

1100

1200

1300

0 50 100 150 200 250 300 350 400 450

Time after Reflood (sec)

Temperature (K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)

Power Turned Off

Heater Rod Temperature during Reflood 

RBHT Exp. 1319

400

500

600

700

800

900

1000

1100

1200

1300

0 50 100 150 200 250 300 350 400 450

Time after Reflood (sec)

Temperature (K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)

Power Turned Off
A-370 

Heater Rod Temperature during Reflood 

RBHT Exp. 1319

400

500

600

700

800

900

1000

1100

1200

1300

0 50 100 150 200 250 300 350 400 450

Time after Reflood (sec)

Temperature (K)

Chan. 195 2.93m (115.4in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.94m (115.7in)

Power Turned Off

Heater Rod Temperature during Reflood 

RBHT Exp. 1319

400

500

600

700

800

900

1000

1100

1200

1300

0 50 100 150 200 250 300 350 400 450

Time after Reflood (sec)

Temperature (K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)

Power Turned Off
A-371 

Heater Rod Temperature during Reflood 

RBHT Exp. 1319

400

500

600

700

800

900

1000

1100

0 50 100 150 200 250 300 350 400 450

Time after Reflood (sec)

Temperature (K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)

Power Turned Off

Heater Rod Temperature during Reflood 

RBHT Exp. 1319

400

500

600

700

800

900

1000

1100

1200

0 50 100 150 200 250 300 350 400 450

Time after Reflood (sec)

Temperature (K)

Chan. 318 2.37m (93.5in)

Chan. 319 2.37m (93.5in)

Power Turned Off
A-372 

Heater Rod Temperature during Reflood 

RBHT Exp. 1319

400

500

600

700

800

900

1000

1100

1200

1300

0 50 100 150 200 250 300 350 400 450

Time after Reflood (sec)

Temperature (K)

Chan. 323 2.54m (100in)

Chan. 324 2.54m (100in)

Chan. 325 2.54m (100in)

Power Turned Off

Heater Rod Temperature during Reflood 

RBHT Exp. 1319

400

500

600

700

800

900

1000

1100

1200

1300

0 50 100 150 200 250 300 350 400 450

Time after Reflood (sec)

Temperature (K)

Chan. 326 2.93m (115.4in)

Chan. 327 2.93m (115.4in)

Chan. 328 2.93m (115.4in)

Power Turned Off
A-373 

Heater Rod Temperature during Reflood 

RBHT Exp. 1319

400

500

600

700

800

900

1000

1100

1200

1300

0 50 100 150 200 250 300 350 400 450

Time after Reflood (sec)

Temperature (K)

Chan. 329 3.05m (120in)

Chan. 330 3.05m (120in)

Chan. 331 3.05m (120in)

Power Turned Off

Heater Rod Temperature during Reflood 

RBHT Exp. 1319

400

500

600

700

800

900

1000

1100

0 50 100 150 200 250 300 350 400 450

Time after Reflood (sec)

Temperature (K)

Chan. 332 3.45m (136in)

Chan. 333 3.45m (136in)

Chan. 334 3.45m (136in)

Power Turned Off
A-374 

Heater Rod Temperature during Reflood 

RBHT Exp. 1319

300

400

500

600

700

800

900

1000

0 50 100 150 200 250 300 350 400 450

Time after Reflood (sec)

Temperature (K)

Chan. 260 1.75m (69in)

Chan. 261 1.75m (69in)

Power Turned Off

Heater Rod Temperature during Reflood 

RBHT Exp. 1319

300

400

500

600

700

800

900

1000

1100

0 50 100 150 200 250 300 350 400 450

Time after Reflood (sec)

Temperature (K)

Chan. 266 2.26m (89in)

Chan. 267 2.26m (89in)

Power Turned Off
A-375 

Heater Rod Temperature during Reflood 

RBHT Exp. 1319

400

500

600

700

800

900

1000

1100

1200

1300

0 50 100 150 200 250 300 350 400 450

Time after Reflood (sec)

Temperature (K)

Chan. 272 2.79m (110in)

Chan. 273 2.79m (110in)

Chan. 275 2.79m (110in)

Power Turned Off

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1319

10

1000

100000

0 50 100 150 200

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)
A-376 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1319

10

1000

100000

0 50 100 150 200

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1319

10

1000

100000

0 50 100 150 200

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)
A-377 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1319

1

100

10000

1000000

0 50 100 150 200

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1319

1

100

10000

1000000

0 50 100 150 200

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 195 2.93m (115.5in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.93m (115.7in)
A-378 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1319

1

100

10000

1000000

0 50 100 150 200

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1319

0.1

10

1000

100000

0 50 100 150 200

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)
A-379 

Quench Data, RBHT Exp. 1319

0

0.5

1

1.5

2

2.5

3

3.5

4

0 50 100 150 200 250 300 350 400 450

Time after Reflood (sec)

Elevation (m)
A-380 
A-381 
A-382 
A-383 

RBHT - REFLOOD TESTS 

SUMMARY SHEET 

RUN NO: 1383

RUN CONDITIONS 

Upper Plenum Pressure: 276 kPa (40 psia) 

Initial Peak Clad Temperature: 1033 degrees K (1400 degrees F) 

Rod Peak Power: 1.31 kW/m (0.4 kW/ft) 

Flooding Rate: 0.0254 m/s (1 in/s) 

Inlet Subcooling: 11 degrees K (20 degrees F) 

Start of Reflood: 313.2 s 

End of Reflood: 1202 s 

Test Date: 8/23/2002 

Comments: 
A-384 

Rod_Elevation Channel Temperature Temperature Turnaround Turnaround Turnaround Quench Quench Quench 

Number at Reflood (K) at Reflood ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F)

B6_0.592m 148 722.19 840.26 10.55 741.9 875.72 59.05 585.62 594.43B6_0.744m 149 757.21 903.3 12.55 780.09 944.48 78.05 568.54 563.68B6_0.846m 150 786.23 955.52 12.55 811.52 1001.04 89.55 587.81 598.37B6_0.897m 151 796.59 974.18 13.05 822.67 1021.12 95.05 603.11 625.91

C6_1.04m 137 842.34 1056.52 17.55 871.93 1109.79 111.55 646.63 704.24D5_1.27m 217 896.04 1153.18 14.05 927.35 1209.54 143.55 649.31 709.06C6_1.34m 138 882.6 1128.99 18.55 917.48 1191.78 159.55 656.95 722.81D5_1.37m 218 913.57 1184.75 19.55 948.77 1248.1 163.05 675.58 756.36C6_1.39m 139 888.21 1139.09 18.05 923.97 1203.45 171.55 655.96 721.04D5_1.45m 219 923.69 1202.95 29.05 960.76 1269.68 178.55 683.43 770.49C6_1.47m 140 898.08 1156.85 30.05 937.24 1227.34 188.55 674.88 755.1D5_1.52m 220 933.2 1220.08 41.05 976.73 1298.42 197.05 700.48 801.18C6_1.62m 141 911.12 1180.33 67.05 971.08 1288.25 230.55 695.4 792.03D5_1.68m 221 944.92 1241.17 62.55 1009.37 1357.18 241.55 723.01 841.72D5_1.78m 222 939.84 1232.02 14.05 973.36 1292.36 271.05 623.99 663.49D5_1.85m 223 956.14 1261.36 62.05 1004.17 1347.83 287.05 685.59 774.37C6_1.87m 142 934.38 1222.19 40.55 984.8 1312.96 299.55 671.38 748.79D5_1.90m 224 963.42 1274.46 67.05 1023.33 1382.31 303.05 707.3 813.45C6_1.95m 144 944.99 1241.29 67.05 1008.49 1355.59 327.55 681.29 766.63C3_2.17m 178 974.68 1294.73 14.55 1017.29 1371.43 420.05 643.95 699.43D4_2.24m 241 1017.48 1371.78 16.05 1058.72 1446 444.55 635.02 683.36D4_2.32m 242 1025.09 1385.48 25.05 1073.12 1471.92 462.05 693.17 788.02C3_2.35m 180 1016.83 1370.6 61.05 1072.82 1471.4 462.05 706.03 811.16D4_2.37m 243 1030.42 1395.07 25.05 1079.11 1482.71 480.05 690.37 782.98C3_2.40m 181 1018.82 1374.19 61.55 1070.56 1467.32 484.05 680.77 765.7D4_2.54m 245 1045.46 1422.13 67.05 1115.95 1549.03 560.55 680.64 765.46D6_2.62m 129 1023.7 1382.97 91.05 1112.41 1542.65 566.05 717.08 831.06D6_2.69m 130 1009.52 1357.45 102.55 1119.06 1554.62 596.05 689.51 781.44C3_2.76m 183 1009.28 1357.01 206.05 1133.85 1581.24 662.05 634.36 682.16D4_2.79m 247 994.99 1331.3 234.05 1065.5 1458.21 691.55 595.22 611.72D6_2.87m 131 949.57 1249.54 17.05 996.35 1333.74 671.55 640.23 692.73D6_2.92m 132 932.93 1219.59 68.05 997.4 1335.63 684.05 683.64 770.86D6_2.97m 133 917.66 1192.1 304.05 1000.42 1341.07 704.05 676.28 757.62D6_3.07m 134 899.12 1158.72 304.05 1004.54 1348.49 727.55 675.16 755.59

E3_3.12m 197 907.53 1173.87 344.05 1010.64 1359.47 763.05 655.36 719.96

D6_3.17m 135 876.93 1118.78 344.05 1001.02 1342.15 752.05 667 740.92D6_3.27m 136 840.04 1052.38 344.05 987.83 1318.41 775.05 648.08 706.85D4_3.61m 248 642.66 697.1 103.05 773.35 932.34 835.55 569.2 564.87
A-385 
A-386 
A-387 
A-388 

Heater Rod Temperature during Reflood 

RBHT Exp. 1383

400

500

600

700

800

900

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

Temperature (K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)
A-389 

Heater Rod Temperature during Reflood 

RBHT Exp. 1383

400

500

600

700

800

900

1000

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

Temperature (K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1383

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

Temperature (K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)
A-390 

Heater Rod Temperature during Reflood 

RBHT Exp. 1383

400

500

600

700

800

900

1000

1100

1200

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

Temperature (K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1383

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

Temperature (K)

Chan. 195 2.93m (115.4in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.94m (115.7in)
A-391 

Heater Rod Temperature during Reflood 

RBHT Exp. 1383

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

Temperature (K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1383

400

500

600

700

800

900

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

Temperature (K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)
A-392 

Steam Probe Temperature during Reflood 

RBHT Exp. 1383

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

Temperature (K)

Chan. 318 2.37m (93.5in)

Chan. 319 2.37m (93.5in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1383

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

Temperature (K)

Chan. 323 2.54m (100in)

Chan. 324 2.54m (100in)

Chan. 325 2.54m (100in)
A-393 

Steam Probe Temperature during Reflood 

RBHT Exp. 1383

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

Temperature (K)

Chan. 326 2.93m (115.4in)

Chan. 327 2.93m (115.4in)

Chan. 328 2.93m (115.4in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1383

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

Temperature (K)

Chan. 329 3.05m (120in)

Chan. 330 3.05m (120in)

Chan. 331 3.05m (120in)
A-394 

Steam Probe Temperature during Reflood 

RBHT Exp. 1383

400

500

600

700

800

900

1000

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

Temperature (K)

Chan. 332 3.45m (136in)

Chan. 333 3.45m (136in)

Chan. 334 3.45m (136in)

Spacer Grid Temperature during Reflood 

RBHT Exp. 1383

400

500

600

700

800

900

1000

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

Temperature (K)

Chan. 260 1.75m (69in)

Chan. 261 1.75m (69in)
A-395 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1383

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

Temperature (K)

Chan. 266 2.26m (89in)

Chan. 267 2.26m (89in)

Spacer Grid Temperature during Reflood 

RBHT Exp. 1383

400

500

600

700

800

900

1000

1100

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

Temperature (K)

Chan. 273 2.79m (110in)

Chan. 275 2.79m (110in)
A-396 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1383

10

1000

100000

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1383

10

1000

100000

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)
A-397 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1383

10

1000

100000

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1383

1

100

10000

1000000

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)
A-398 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1383

1

100

10000

1000000

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 195 2.93m (115.5in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.93m (115.7in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1383

1

100

10000

1000000

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)
A-399 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1383

1

100

10000

1000000

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)

Quench Data, RBHT Exp. 1383

0

0.5

1

1.5

2

2.5

3

3.5

4

0 100 200 300 400 500 600 700 800 900

Time after Reflood (sec)

Elevation (m)
A-400 
A-401 
A-402 
A-403 

RBHT - REFLOOD TESTS 

SUMMARY SHEET 

RUN NO: 1389

RUN CONDITIONS 

Upper Plenum Pressure: 276 kPa (40 psia) 

Initial Peak Clad Temperature: 1033 degrees K (1400 degrees F) 

Rod Peak Power: 1.31 kW/m (0.4 kW/ft) 

Flooding Rate: 0.0254 m/s (1 in/s) 

Inlet Subcooling: 11 degrees K (20 degrees F) 

Start of Reflood: 139.6 s 

End of Reflood: 1529 s 

Test Date: 8/26/2002 

Comments: 
A-404 

Rod_Elevation Channel Temperature Temperature Turnaround Turnaround Turnaround Quench Quench Quench 

Number at Reflood (K) at Reflood ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F)

B6_0.592m 148 666.54 740.09 9.15 685.06 773.43 52.15 565.42 558.07B6_0.744m 149 681.68 767.33 10.65 702.36 804.56 67.15 547.91 526.55B6_0.846m 150 703.79 807.13 11.15 726.89 848.71 76.15 573.44 572.5B6_0.897m 151 712.14 822.16 12.65 736.75 866.46 81.15 586.7 596.37

C6_1.04m 137 747.74 886.24 15.65 776.18 937.44 97.65 611.06 640.22D5_1.27m 217 793.06 967.81 15.65 824.81 1024.97 126.15 610.58 639.36C6_1.34m 138 787.46 957.75 19.15 820.65 1017.48 138.65 621.11 658.31D5_1.37m 218 813.7 1004.97 19.15 848.28 1067.22 141.65 642.9 697.53C6_1.39m 139 794.7 970.77 55.15 832.11 1038.11 147.65 637.63 688.04D5_1.45m 219 826.38 1027.8 57.15 869.38 1105.19 154.65 650.69 711.55C6_1.47m 140 806.36 991.76 57.15 854.29 1078.04 163.65 642.4 696.63D5_1.52m 220 839.27 1051 60.65 893.5 1148.62 172.65 662.3 732.46C6_1.62m 141 828.62 1031.83 63.65 898.45 1157.52 200.65 658.89 726.31D5_1.68m 221 864.36 1096.17 63.65 937.9 1228.54 212.15 691.8 785.55D5_1.78m 222 872.62 1111.02 12.15 901.27 1162.59 240.65 605.5 630.2D5_1.85m 223 897.05 1155 25.65 934.78 1222.91 257.65 667 740.91C6_1.87m 142 877.42 1119.67 63.65 926.69 1208.35 271.15 650.99 712.09D5_1.90m 224 912.6 1182.99 59.65 958.77 1266.09 275.65 662.18 732.24C6_1.95m 144 900.71 1161.59 63.65 957.18 1263.23 303.15 608.64 635.87C3_2.17m 178 952.72 1255.21 64.15 991.48 1324.97 394.15 630.48 675.18D4_2.24m 241 995.22 1331.71 14.15 1031.08 1396.25 416.15 642.89 697.51D4_2.32m 242 1004.96 1349.25 63.65 1071.22 1468.51 443.15 622.93 661.58C3_2.35m 180 996.46 1333.93 68.15 1067.32 1461.49 448.65 655.61 720.41D4_2.37m 243 1012.23 1362.33 79.65 1079.77 1483.89 463.65 651.13 712.34C3_2.40m 181 1000.67 1341.53 68.15 1068.24 1463.14 470.15 660.43 729.09D4_2.54m 245 1033.09 1399.87 145.15 1124.8 1564.95 551.15 653.87 717.28D6_2.62m 129 1013.03 1363.76 148.15 1114.53 1546.47 557.65 690.33 782.91D6_2.69m 130 1009.11 1356.71 177.15 1136.22 1585.51 601.65 694.51 790.44C3_2.76m 183 1008.92 1356.37 178.65 1157.35 1623.54 666.15 663.47 734.56D4_2.79m 247 997.33 1335.51 219.65 1103.01 1525.73 702.15 620.18 656.64D6_2.87m 131 957.29 1263.43 219.15 1017.35 1371.54 681.15 656.04 721.18D6_2.92m 132 937.02 1226.95 221.15 1036.75 1406.46 700.15 647.63 706.05D6_2.97m 133 913.02 1183.75 221.15 1039.4 1411.23 725.15 650.76 711.69D6_3.07m 134 882.91 1129.54 275.65 1038.49 1409.59 753.15 663.28 734.22

E3_3.12m 197 875.65 1116.48 331.15 1056.5 1442.01 797.15 651.39 712.82

D6_3.17m 135 853.38 1076.4 331.15 1033.48 1400.58 779.15 670.33 746.91D6_3.27m 136 813.24 1004.14 352.65 1021.36 1378.76 803.15 673.89 753.31D4_3.61m 248 611.29 640.64 487.15 860.32 1088.89 892.65 598.55 617.71
A-405 
A-406 
A-407 
A-408 

Heater Rod Temperature during Reflood 

RBHT Exp. 1389

400

450

500

550

600

650

700

750

800

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

Temperature (K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1389

400

500

600

700

800

900

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

Temperature (K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)
A-409 

Heater Rod Temperature during Reflood 

RBHT Exp. 1389

400

500

600

700

800

900

1000

1100

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

Temperature (K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1389

400

500

600

700

800

900

1000

1100

1200

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

Temperature (K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)
A-410 

Heater Rod Temperature during Reflood 

RBHT Exp. 1389

400

500

600

700

800

900

1000

1100

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

Temperature (K)

Chan. 195 2.93m (115.4in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.94m (115.7in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1389

400

500

600

700

800

900

1000

1100

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

Temperature (K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)
A-411 

Heater Rod Temperature during Reflood 

RBHT Exp. 1389

400

500

600

700

800

900

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

Temperature (K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1389

400

500

600

700

800

900

1000

1100

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

Temperature (K)

Chan. 318 2.37m (93.5in)

Chan. 319 2.37m (93.5in)
A-412 

Steam Probe Temperature during Reflood 

RBHT Exp. 1389

400

500

600

700

800

900

1000

1100

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

Temperature (K)

Chan. 323 2.54m (100in)

Chan. 324 2.54m (100in)

Chan. 325 2.54m (100in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1389

400

500

600

700

800

900

1000

1100

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

Temperature (K)

Chan. 326 2.93m (115.4in)

Chan. 327 2.93m (115.4in)

Chan. 328 2.93m (115.4in)
A-413 

Steam Probe Temperature during Reflood 

RBHT Exp. 1389

400

500

600

700

800

900

1000

1100

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

Temperature (K)

Chan. 329 3.05m (120in)

Chan. 330 3.05m (120in)

Chan. 331 3.05m (120in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1389

400

500

600

700

800

900

1000

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

Temperature (K)

Chan. 332 3.45m (136in)

Chan. 333 3.45m (136in)

Chan. 334 3.45m (136in)
A-414 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1389

400

500

600

700

800

900

1000

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

Temperature (K)

Chan. 260 1.75m (69in)

Chan. 261 1.75m (69in)

Spacer Grid Temperature during Reflood 

RBHT Exp. 1389

400

500

600

700

800

900

1000

1100

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

Temperature (K)

Chan. 266 2.26m (89in)

Chan. 267 2.26m (89in)
A-415 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1389

400

500

600

700

800

900

1000

1100

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

Temperature (K)

Chan. 272 2.79m (110in)

Chan. 273 2.79m (110in)

Chan. 275 2.79m (110in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1389

10

1000

100000

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)
A-416 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1389

10

1000

100000

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1389

10

1000

100000

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)
A-417 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1389

1

100

10000

1000000

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1389

1

100

10000

1000000

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 195 2.93m (115.5in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.93m (115.7in)
A-418 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1389

1

100

10000

1000000

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1389

1

100

10000

1000000

0 200 400 600 800 1000 1200 1400

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)
A-419 

Quench Data, RBHT Exp. 1389

0

0.5

1

1.5

2

2.5

3

3.5

4

0 200 400 600 800 1000

Time after Reflood (sec)

Elevation (m)
A-420 
A-421 
A-422 
A-423 

RBHT - REFLOOD TESTS 

SUMMARY SHEET 

RUN NO: 1402

RUN CONDITIONS 

Upper Plenum Pressure: 276 kPa (40 psia) 

Initial Peak Clad Temperature: 1033 degrees K (1400 degrees F) 

Rod Peak Power: 1.31 kW/m (0.4 kW/ft) 

Flooding Rate: 0.0254 m/s (1 in/s) 

Inlet Subcooling: 11 degrees K (20 degrees F) 

Start of Reflood: 465.2 s 

End of Reflood: 2440 s 

Test Date: 8/26/2002 

Comments: 
A-424 

Rod_Elevation Channel Temperature Temperature Turnaround Turnaround Turnaround Quench Quench Quench 

Number at Reflood (K) at Reflood ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F)

B6_0.592m 148 742.45 876.72 6.55 753.93 897.39 75.05 572.72 571.2B6_0.744m 149 791.15 964.39 7.05 803.24 986.15 97.05 566.29 559.63B6_0.846m 150 822.23 1020.32 7.55 835.79 1044.73 110.55 590.34 602.92B6_0.897m 151 832.91 1039.56 7.55 847.08 1065.05 118.05 606.78 632.51

C6_1.04m 137 872.31 1110.48 8.05 888.36 1139.36 143.55 653.99 717.49D5_1.27m 217 932.84 1219.42 8.55 949.95 1250.23 188.05 646.16 703.39C6_1.34m 138 923.02 1201.75 63.05 951.59 1253.18 206.05 668.85 744.24D5_1.37m 218 955.81 1260.78 63.05 992.36 1326.56 213.55 687.27 777.4C6_1.39m 139 930.73 1215.62 63.05 967.16 1281.19 221.55 673.29 752.24D5_1.45m 219 969.61 1285.61 63.05 1016.02 1369.15 235.55 701.89 803.71C6_1.47m 140 945.74 1242.65 64.05 990.81 1323.77 245.05 686.03 775.16D5_1.52m 220 980.92 1305.97 63.05 1038.2 1409.07 260.05 689.73 781.83C6_1.62m 141 959.71 1267.79 64.55 1028.93 1392.39 300.05 646.17 703.41D5_1.68m 221 987.3 1317.46 65.05 1070.87 1467.88 319.55 688.84 780.23D5_1.78m 222 981.5 1307.01 64.55 1018.63 1373.84 350.05 623.94 663.41D5_1.85m 223 1010.13 1358.55 65.05 1065.62 1458.44 371.55 661.4 730.84C6_1.87m 142 994.58 1330.56 65.55 1057.25 1443.36 384.55 665.24 737.74D5_1.90m 224 1020.35 1376.94 64.55 1087.49 1497.79 395.05 678.63 761.85C6_1.95m 144 1005.64 1350.46 65.55 1078.78 1482.11 420.55 684.22 771.9C3_2.17m 178 1014.36 1366.17 64.55 1089.42 1501.28 529.55 612.65 643.08D4_2.24m 241 1066.3 1459.65 65.05 1101.62 1523.23 551.55 649.5 709.42D4_2.32m 242 1081.3 1486.64 65.05 1143.77 1599.11 574.55 670.55 747.31C3_2.35m 180 1077.18 1479.24 65.55 1141.33 1594.7 581.55 675.33 755.9D4_2.37m 243 1089.82 1501.99 65.05 1156.93 1622.78 600.55 658.74 726.05C3_2.40m 181 1081.43 1486.89 65.05 1146.46 1603.94 607.55 676.98 758.87D4_2.54m 245 1116.29 1549.63 64.55 1197.16 1695.2 723.05 598.53 617.66D6_2.62m 129 1104.69 1528.75 64.55 1192.61 1687.02 733.55 623.34 662.33D6_2.69m 130 1099.62 1519.63 64.55 1199.62 1699.63 777.05 670.12 746.52C3_2.76m 183 1085.31 1493.88 81.55 1199.73 1699.83 836.55 665.37 737.97D4_2.79m 247 1058.58 1445.76 64.05 1162.63 1633.05 882.55 620.14 656.57D6_2.87m 131 1049.29 1429.03 64.05 1095.88 1512.89 858.05 658.46 725.54D6_2.92m 132 1032.96 1399.64 65.55 1099.47 1519.35 877.05 665.35 737.93D6_2.97m 133 1009.19 1356.85 65.55 1085.2 1493.67 902.55 666.08 739.26D6_3.07m 134 976.79 1298.53 65.55 1062.46 1452.74 931.55 667.49 741.79

E3_3.12m 197 972.77 1291.3 402.55 1073.57 1472.73 981.55 644.11 699.71

D6_3.17m 135 935.63 1224.45 402.55 1050.86 1431.86 961.55 668.44 743.5D6_3.27m 136 874.01 1113.52 463.05 1038.15 1408.99 988.05 652.89 715.51D4_3.61m 248 661.67 731.31 493.55 881.08 1126.26 1085.55 577.7 580.18
A-425 
A-426 
A-427 
A-428 

Heater Rod Temperature during Reflood 

RBHT Exp. 1402

400

500

600

700

800

900

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

Temperature (K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1402

400

500

600

700

800

900

1000

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

Temperature (K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)
A-429 

Heater Rod Temperature during Reflood 

RBHT Exp. 1402

400

500

600

700

800

900

1000

1100

1200

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

Temperature (K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1402

400

500

600

700

800

900

1000

1100

1200

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

Temperature (K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)
A-430 

Heater Rod Temperature during Reflood 

RBHT Exp. 1402

400

500

600

700

800

900

1000

1100

1200

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

Temperature (K)

Chan. 195 2.93m (115.4in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.94m (115.7in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1402

400

500

600

700

800

900

1000

1100

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

Temperature (K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)
A-431 

Heater Rod Temperature during Reflood 

RBHT Exp. 1402

400

500

600

700

800

900

1000

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

Temperature (K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1402

400

500

600

700

800

900

1000

1100

1200

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

Temperature (K)

Chan. 318 2.37m (93.5in)

Chan. 319 2.37m (93.5in)
A-432 

Steam Probe Temperature during Reflood 

RBHT Exp. 1402

400

500

600

700

800

900

1000

1100

1200

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

Temperature (K)

Chan. 323 2.54m (100in)

Chan. 324 2.54m (100in)

Chan. 325 2.54m (100in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1402

400

500

600

700

800

900

1000

1100

1200

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

Temperature (K)

Chan. 326 2.93m (115.4in)

Chan. 327 2.93m (115.4in)

Chan. 328 2.93m (115.4in)
A-433 

Steam Probe Temperature during Reflood 

RBHT Exp. 1402

400

500

600

700

800

900

1000

1100

1200

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

Temperature (K)

Chan. 329 3.05m (120in)

Chan. 330 3.05m (120in)

Chan. 331 3.05m (120in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1402

400

500

600

700

800

900

1000

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

Temperature (K)

Chan. 332 3.45m (136in)

Chan. 333 3.45m (136in)

Chan. 334 3.45m (136in)
A-434 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1402

400

500

600

700

800

900

1000

1100

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

Temperature (K)

Chan. 260 1.75m (69in)

Chan. 261 1.75m (69in)

Spacer Grid Temperature during Reflood 

RBHT Exp. 1402

400

500

600

700

800

900

1000

1100

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

Temperature (K)

Chan. 266 2.26m (89in)

Chan. 267 2.26m (89in)
A-435 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1402

400

500

600

700

800

900

1000

1100

1200

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

Temperature (K)

Chan. 272 2.79m (110in)

Chan. 273 2.79m (110in)

Chan. 275 2.79m (110in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1402

10

1000

100000

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)
A-436 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1402

10

1000

100000

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1402

10

1000

100000

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)
A-437 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1402

1

100

10000

1000000

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1402

1

100

10000

1000000

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 195 2.93m (115.5in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.93m (115.7in)
A-438 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1402

1

100

10000

1000000

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1402

1

100

10000

1000000

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)
A-439 

Quench Data, RBHT Exp. 1402

0

0.5

1

1.5

2

2.5

3

3.5

4

0 200 400 600 800 1000 1200

Time after Reflood (sec)

Elevation (m)
A-440 
A-441 
A-442 
A-443 

RBHT - REFLOOD TESTS 

SUMMARY SHEET 

RUN NO: 1407

RUN CONDITIONS

Upper Plenum Pressure: 276 kPa (40 psia) 

Initial Peak Clad Temperature: 1144 degrees K (1600 degrees F) 

Rod Peak Power: 2.3 kW/m (0.7 kW/ft) 

Flooding Rate: 0.0762 m/s (3 in/s) 

Inlet Subcooling: 23 degrees K (41 degrees F) 

Start of Reflood: 126.3 s 

End of Reflood: 2030 s 

Test Date: 8/29/2002 

Comments: 
A-444 

Rod_Elevation Channel Temperature Temperature Turnaround Turnaround Turnaround Quench Quench Quench 

Number at Reflood (K) at Reflood ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F) Time (sec.) Temperature (K) Temperature ( ̊F)

B6_0.592m 148 753.92 897.38 3.95 764.92 917.17 48.95 587.54 597.89B6_0.744m 149 768.57 923.74 4.45 781.34 946.72 67.95 583.36 590.35B6_0.846m 150 793.83 969.21 4.45 808.58 995.76 77.45 604.92 629.18B6_0.897m 151 803.72 987.01 4.45 819.13 1014.74 82.45 609.58 637.56

C6_1.04m 137 847.36 1065.56 5.45 864.84 1097.02 93.95 660.1 728.49D5_1.27m 217 899.16 1158.79 5.95 918 1192.71 122.95 685.23 773.73C6_1.34m 138 896.02 1153.15 5.95 916.49 1190 135.45 697.92 796.56D5_1.37m 218 922.22 1200.31 5.95 942.85 1237.45 138.95 712.93 823.58C6_1.39m 139 903.17 1166.02 5.95 923.81 1203.16 144.45 704.59 808.57D5_1.45m 219 937.78 1228.31 5.95 959.13 1266.74 150.95 721.97 839.86C6_1.47m 140 918.46 1193.54 5.95 940.05 1232.4 157.95 720.38 836.99D5_1.52m 220 953.24 1256.15 5.95 975.01 1295.34 165.45 742.89 877.52C6_1.62m 141 947.4 1245.63 16.95 972.32 1290.48 188.95 757.48 903.78D5_1.68m 221 984.14 1311.76 17.95 1009.6 1357.59 197.95 778.3 941.25D5_1.78m 222 986.29 1315.63 4.95 1004.39 1348.21 219.95 682.03 767.97D5_1.85m 223 1014.52 1366.45 5.95 1036.73 1406.43 233.95 762.51 912.84C6_1.87m 142 999.42 1339.26 5.95 1023.57 1382.74 243.45 767.06 921.02D5_1.90m 224 1026.67 1388.33 5.45 1049.92 1430.17 245.95 781.44 946.9C6_1.95m 144 1015.23 1367.72 5.95 1039.76 1411.88 262.95 774.28 934.02C3_2.17m 178 1044.24 1419.95 5.45 1068.87 1464.28 316.45 727.21 849.3D4_2.24m 241 1098.38 1517.4 4.95 1121.51 1559.03 355.45 699.42 799.27D4_2.32m 242 1107.52 1533.85 5.45 1133.4 1580.44 374.95 732.43 858.68C3_2.35m 180 1102.29 1524.43 5.95 1130.1 1574.49 350.95 794.05 969.6D4_2.37m 243 1114.68 1546.74 5.45 1141.12 1594.32 388.45 737.76 868.28C3_2.40m 181 1105.27 1529.79 5.45 1132.96 1579.65 362.45 807.57 993.94D4_2.54m 245 1141.2 1594.47 4.95 1165.63 1638.45 441.95 726.92 848.78D6_2.62m 129 1130.07 1574.44 4.95 1155.36 1619.95 434.45 758.32 905.29D6_2.69m 130 1121.06 1558.21 5.45 1147.57 1605.94 450.95 769.65 925.68C3_2.76m 183 1118.56 1553.73 5.45 1145.42 1602.08 451.95 796.1 973.29D4_2.79m 247 1089.99 1502.29 4.45 1115.22 1547.7 501.95 698.54 797.69D6_2.87m 131 1061.16 1450.39 4.45 1083.88 1491.3 483.45 716.01 829.13D6_2.92m 132 1039.46 1411.35 5.95 1067.87 1462.47 492.95 738.46 869.53D6_2.97m 133 1021.06 1378.21 5.95 1048.24 1427.15 503.95 723.4 842.43D6_3.07m 134 995.41 1332.05 5.95 1020.72 1377.61 516.95 710.01 818.33

E3_3.12m 197 997.13 1335.14 5.45 1022.53 1380.86 538.95 714.07 825.65

D6_3.17m 135 958.98 1266.48 5.95 983.4 1310.44 530.45 691.84 785.63D6_3.27m 136 905.56 1170.33 5.95 930.12 1214.53 541.95 684.99 773.29D4_3.61m 248 690.79 783.74 5.95 720.06 836.41 602.95 578.68 581.93
A-445 
A-446 
A-447 
A-448 

Heater Rod Temperature during Reflood 

RBHT Exp. 1407

400

500

600

700

800

900

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

Temperature (K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1407

400

500

600

700

800

900

1000

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

Temperature (K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)
A-449 

Heater Rod Temperature during Reflood 

RBHT Exp. 1407

400

500

600

700

800

900

1000

1100

1200

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

Temperature (K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1407

400

500

600

700

800

900

1000

1100

1200

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

Temperature (K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)
A-450 

Heater Rod Temperature during Reflood 

RBHT Exp. 1407

400

500

600

700

800

900

1000

1100

1200

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

Temperature (K)

Chan. 195 2.93m (115.4in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.94m (115.7in)

Heater Rod Temperature during Reflood 

RBHT Exp. 1407

400

500

600

700

800

900

1000

1100

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

Temperature (K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)
A-451 

Heater Rod Temperature during Reflood 

RBHT Exp. 1407

400

500

600

700

800

900

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

Temperature (K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1407

400

500

600

700

800

900

1000

1100

1200

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

Temperature (K)

Chan. 318 2.37m (93.5in)

Chan. 319 2.37m (93.5in)
A-452 

Steam Probe Temperature during Reflood 

RBHT Exp. 1407

400

500

600

700

800

900

1000

1100

1200

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

Temperature (K)

Chan. 323 2.54m (100in)

Chan. 324 2.54m (100in)

Chan. 325 2.54m (100in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1407

400

500

600

700

800

900

1000

1100

1200

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

Temperature (K)

Chan. 326 2.93m (115.4in)

Chan. 327 2.93m (115.4in)

Chan. 328 2.93m (115.4in)
A-453 

Steam Probe Temperature during Reflood 

RBHT Exp. 1407

400

500

600

700

800

900

1000

1100

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

Temperature (K)

Chan. 329 3.05m (120in)

Chan. 330 3.05m (120in)

Chan. 331 3.05m (120in)

Steam Probe Temperature during Reflood 

RBHT Exp. 1407

400

500

600

700

800

900

1000

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

Temperature (K)

Chan. 332 3.45m (136in)

Chan. 333 3.45m (136in)

Chan. 334 3.45m (136in)
A-454 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1407

400

500

600

700

800

900

1000

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

Temperature (K)

Chan. 260 1.75m (69in)

Chan. 261 1.75m (69in)

Spacer Grid Temperature during Reflood 

RBHT Exp. 1407

400

500

600

700

800

900

1000

1100

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

Temperature (K)

Chan. 266 2.26m (89in)

Chan. 267 2.26m (89in)
A-455 

Spacer Grid Temperature during Reflood 

RBHT Exp. 1407

400

500

600

700

800

900

1000

1100

1200

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

Temperature (K)

Chan. 272 2.79m (110in)

Chan. 273 2.79m (110in)

Chan. 275 2.79m (110in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1407

10

1000

100000

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 56 0.98m (38.4in)

Chan. 88 0.97m (38.3in)

Chan. 120 0.97m (38.3in)
A-456 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1407

10

1000

100000

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 59 1.4m (55in)

Chan. 107 1.4m (55in)

Chan. 155 1.4m (55in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1407

10

1000

100000

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 235 2.37m (93.4in)

Chan. 243 2.37m (93.2in)
A-457 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1407

1

100

10000

1000000

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 205 2.54m (100.9in)

Chan. 237 2.54m (100.1in)

Chan. 245 2.54m (100.1in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1407

1

100

10000

1000000

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 195 2.93m (115.5in)

Chan. 211 2.93m (115.4in)

Chan. 227 2.93m (115.7in)
A-458 

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1407

1

100

10000

1000000

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 70 3.07m (120.8in)

Chan. 134 3.07m (120.9in)

Chan. 196 3.01m (118.5in)

Heat Transfer Coefficient during Reflood 

RBHT Exp. 1407

1

100

10000

1000000

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Time after Reflood (sec)

HTC (W/m 2-K)

Chan. 200 3.45m (135.6in)

Chan. 216 3.45m (135.6in)

Chan. 232 3.45m (135.7in)
A-459 

Quench Data, RBHT Exp. 1407

0

0.5

1

1.5

2

2.5

3

3.5

4

0 100 200 300 400 500 600 700

Time after Reflood (sec)

Elevation (m)
A-460 
A-461 
A-462 
B-1 

APPENDIX B. UNCERTAINTIES 

This appendix describes the measurement errors in the calculations performed for the analysis. 

The first section contains the error analysis for temperature, pressure and flow measurements. 

The second section describes the uncertainty analysis for the heat transfer coefficient 

calculations. 

B.1 Measurement Errors

The instrumentation error associated with the data from RBHT test series can be derived either 

from equipment manufacturers’ specifications or system calibration data. Component 

calibrations are performed to verify that the manufacturers’ specifications are met, and these 

manufacturers’ specifications are used to compute the error estimate for the data path. System 

calibrations are performed when component calibrations are not expedient or when an accuracy 

improvement could be accomplished with a system calibration. The system calibration data are 

used to compute an estimate of error for the system response, and calibration data points. The 

total system error from a system calibration is a function of both system response error and 

calibration data error. 

In all cases of error estimate, the standard deviation has been computed and presented as the 

most probable error. The manufacturer-specified error is the maximum possible error. The 

standard deviation error is calculated from the maximum error by the following: 

= 













 =

n

i

i

n

E

1

2

2 ρ (B-1) 

where 

ρ2

 data path standard deviation 

2 Ei component i maximum error 

n number of sources of error 

When a system calibration is performed, the standard deviation from the calibration data and 

that from the calibration equipment can be combined by the following equation to produce the 

best estimate of error: 

2 2 ρ = Ed + Ec (B-2) 

where 

Ed calibration data standard deviation 

Ec calibration equipment standard deviation 

The calibration data standard deviation is a measure of the error involved in fitting the 

calibration data. That is, 
B-2 

1/ 2

1

2 ( )























 −

=

=

n

Y Y

E

n

i

i f

d (B-3) 

where 

Yi calibration point 

Yf predicted output from the calibrations curve 

n number of calibration points 

The calibration equipment standard deviation is a measure of the absolute error of the 

calibration point. If the calibration point in the above equation is calculated from and equation of 

the form 

1 2 3 Y = x .x .x (B-4) 

then 

= 













 = 













 n

i

y x

y x

i

1

2 2

σ σ (B-5) 

and 

2 Ec = σ y (B-6) 

The data path has been broken down into three parts called sensor, conditioner, and readout. 

The sensor is the device whose electrical output is proportional to a physical quantity 

(temperature, pressure, flow, power). The conditioner is a device which matches the electrical 

output of the sensor to the input requirements of the readout device. The readout device 

measures and records the electrical value of the signal from the conditioner. This recorded 

electrical value is subsequently used to compute the physical quantity it represents. The errors 

due to the transmission wire errors are very small (±0.001 percent) in comparison to the 

element errors and are considered negligible. 

The error values for sensor, conditioning, and readout are the manufacturers’ specifications in 

engineering units. These numbers are used to compute the most probable error, as previously 

described. Where systems calibrations are performed, the equipment calibration data provide 

the standard deviation and maximum error as computed from the calibration data points in fitting 

the points to a first-order polynomial. The calibration point standard deviation is computed using 

the method described above. The calibration point maximum error occurs simultaneously in 

each component of the calibration equation. The overall system standard deviation may then 

be calculated using Equation (B-2). 

The calculated Total Probable Errors using Equation (B-2) for each instrumentation channel are 

shown in the following tables: 
B-3 

Table B.1 Temperature measurements including the heater rods, grid fluid, grid walls, 

 support rods, steam probe rakes, flow housing walls, flow housing insulation, 

 vessel and piping walls, and quartz windows thermocouples. 

Table B.2 Differential pressure cells (DP’s), static pressure transducers (P’s), and vessels 

 liquid label transducers. 

Table B.3 Inlet Mass and exhaust steam flow transmitters (FM). 

Table B.4 Steam probe rakes linear position transmitter. 

Table B.5 Heater Rod Bundle input voltage (V), amperage (Amps), and Power (W) 

 measurements. 
B-4 

Table B.1 Error in Temperature Measurement 

INSTRUMENT DATA ACQUISITION SYSTEM

INPUT SENSOR RANGE ERROR ± 1.11°C SCP

AUTORANGING

± 0.02% 

TEMPERATU

RE RANGE

REF JCTN 

MEAS

ISO REF 

GRADIENT

TEMP RANGE 

FOR ERROR 

NUMBERS

CHANNEL NO. TYPE K TC °C ± °C ± °C ± °C ± °C ± °C °C

0.20 0.08 0.01 0.20 0 TO 3750.25 0.16 0.01 0.20 375 TO 8000.40 0.27 0.01 0.20 800 TO 13710.20 0.08 0.01 0.20 0 TO 3750.25 0.16 0.01 0.20 375 TO 8000.40 0.27 0.01 0.20 800 TO 13710.20 0.08 0.01 0.20 0 TO 3750.25 0.16 0.01 0.20 375 TO 8000.40 0.27 0.01 0.20 800 TO 13710.20 0.08 0.01 0.20 0 TO 3750.25 0.16 0.01 0.20 375 TO 8000.40 0.27 0.01 0.20 800 TO 13710.20 0.08 0.01 0.20 0 TO 3750.25 0.16 0.01 0.20 375 TO 8000.40 0.27 0.01 0.20 800 TO 1371

97, 184, 277, 400 INSULATION 10 - 1371 °C 1.11 0.20 0.08 0.01 0.20 0 TO 375

386 THRU 388 L. PLEN. FL & WALL 10 - 1371 °C 1.11 0.20 0.08 0.01 0.20 0 TO 375

389, 391, 392 U. PLEN. FL & WALL 10 - 1371 °C 1.11 0.20 0.08 0.01 0.20 0 TO 375

399, 401 SUPPLY TANK FLUID 10 - 1371 °C 1.11 0.20 0.08 0.01 0.20 0 TO 375

407 THRU 410 SUP LINE FL. & WALL 10 - 1371 °C 1.11 0.20 0.08 0.01 0.20 0 TO 375418 THRU 424 (SM, LG) CARRYOVER TANKS FL. & WALL 10 - 1371 °C 1.11 0.20 0.08 0.01 0.20 0 TO 375

385, 404, 435, 

436, 437

PRESS. OSC. DAMP TANK FL, & 

WALL 10 - 1371 °C 1.11 0.20 0.08 0.01 0.20 0 TO 375

440 THRU 443 EXHAUST LINE 10 - 1371 °C 1.11 0.20 0.08 0.01 0.20 0 TO 375

360, 361 ROD BUNDLE INLET 10 - 1371 °C 1.11 0.20 0.08 0.01 0.20 0 TO 375

414-415 STM SUP FL & WALL 10 - 1371 °C 1.11 0.20 0.08 0.01 0.20 0 TO 375

403, 428-432 STEAM SEP 10 - 1371 °C 1.11 0.20 0.08 0.01 0.20 0 TO 375

10 - 1371 °C 0.20 0.08 0.01 0.200 0 TO 37510 - 1371 °C 0.25 0.160 0.01 0.200 375 TO 800

CHANNEL NO. THERMISTOR TYPE 5000 °C ± °C ± °C ± °C ± °C ± °C °C

497-512 TERM PNL REF THERMISTORS -10 - 85 °C 0.01 -10 TO 65

1-96, 98-183, 185-

248, 311-313 HEATER ROD'S 10 - 1371 °C 1.11

249-276, 278-279 GRID WALL & FLUID 10 - 1371 °C 1.11

280 THRU 295 SUPPORT RODS 10 - 1371 °C 1.11

296-310, 314-334, 

493-495 ST. PROBE RAKES 10 - 1371 °C 1.11446-457 QUARTZ WINDOWS 1.11

335 THRU 359, & 

496 FLOW HOUSING WALL 10 - 1371 °C 1.11
B-5 

Table B.2 Error in Differential Pressure Cells (DP’s), Static Pressure Transducers (P’s), and 

Vessels Liquid Label Transducers 

SPAN

(CALIBRATION)

ACCURACY

± 0.075% SPAN

PERFORMANC

E

± 0.15% SPAN

SCP 

LINEARITY

± 0.01% 

VOLTAGE 

RANGE

AUTORANGING

± 0.02% 

VOLTAGE 

RANGE

SCP OFFSET 

ERROR NOISE

VOLTAGE 

RANGE FOR 

ERROR 

NUMBERS

TOTAL 

PROBABLE 

ERROR

mm H20 ± mm H20 ± mm H20 ± mm H20 ± mm H20 ± mm H20 ± mm H20 ± Volts ± mm H20

0.003 0.005 0.001 0.002 0.25 0.130.010 0.021 0.003 0.007 1.00 0.130.003 0.007 0.001 0.003 0.25 0.170.014 0.027 0.004 0.009 1.00 0.170.004 0.009 0.001 0.004 0.25 0.210.017 0.034 0.005 0.011 1.00 0.220.005 0.010 0.002 0.005 0.25 0.260.021 0.041 0.006 0.013 1.00 0.260.006 0.012 0.002 0.006 0.25 0.300.024 0.048 0.007 0.015 1.00 0.300.007 0.014 0.002 0.006 0.25 0.340.027 0.055 0.009 0.018 1.00 0.350.009 0.019 0.003 0.009 0.25 0.470.038 0.075 0.012 0.024 1.00 0.480.010 0.021 0.003 0.009 0.25 0.510.041 0.082 0.013 0.026 1.00 0.520.011 0.022 0.004 0.010 0.25 0.550.045 0.089 0.014 0.029 1.00 0.560.123 0.247 0.039 0.114 0.25 6.140.494 0.987 0.153 0.316 1.00 6.240.011 0.021 0.003 0.010 0.25 0.520.042 0.084 0.013 0.027 1.00 0.530.004 0.009 0.001 0.004 0.25 0.210.017 0.034 0.005 0.011 1.00 0.220.005 0.011 0.002 0.005 0.25 0.260.021 0.042 0.007 0.013 1.00 0.270.214 0.429 0.069 0.197 0.25 10.660.857 1.714 0.266 0.549 1.00 10.840.102 0.204 0.033 0.094 0.25 5.080.408 0.816 0.126 0.261 1.00 5.160.053 0.106 0.017 0.049 0.25 2.640.213 0.425 0.066 0.136 1.00 2.690.030 0.060 0.010 0.028 0.25 1.500.121 0.242 0.037 0.077 1.00 1.530.056 0.112 0.018 0.052 0.25 2.790.225 0.449 0.070 0.144 1.00 2.84

kPa ± kPa ± kPa ± kPa ± kPa ± kPa ± kPa ± Volts ± kPa

0.014 0.028 0.004 0.013 0.25 0.690.056 0.112 0.017 0.036 1.00 0.710.023 0.047 0.007 0.021 0.25 1.160.093 0.186 0.029 0.060 1.00 1.180.012 0.023 0.004 0.011 0.25 0.580.047 0.093 0.014 0.030 1.00 0.590.001 0.002 0.000 0.001 0.25 0.060.005 0.009 0.001 0.003 1.00 0.06

0.110.150.190.230.270.300.420.460.505.490.470.190.239.534.532.361.342.500.621.030.520.05

0 TO 895.35 mm H20 0.67

0 TO 76.2 mm H20 0.06

0 TO 101.6 mm H20 0.08

0 TO 127 mm H20 0.10

0 TO 152.4 mm H20 0.110 TO 177.8 mm H20 0.130 TO 203.2 mm H20 0.150 TO 279.4 mm H20 0.210 TO 304.8 mm H20 0.230 TO 330.2 mm H20 0.25

0 TO 3657.6 mm H20 2.740 TO 311.15 mm H20 0.23

0 TO 127 mm H20 0.10

0 TO 413.7 kPa 0.31

0 TO 155.575 mm H20 0.12

0 TO 689.5 kPa 0.52

0 TO 6350 mm H20 4.76

0 TO 3022.6 mm H20 2.27

0 TO 344.7 kPa 0.26

0 TO 1574.8 mm H20 1.180 TO 1663.7 mm H20 1.25

0 TO 34.5 kPa 0.03
B-6 

Table B.3 Error in Inlet Mass and Exhaust Steam Flow Transmitters (FM) 

INSTRUMENT DATA ACQUISITION SYSTEM TOTAL

INPUT SENSOR SPAN (CALIBRATION) ACCURACY1 ± 0.11% SPAN

SCP 

LINEARITY

± 0.01% 

VOLTAGE 

RANGE

AUTORANGING

± 0.02% 

VOLTAGE 

RANGE

SCP OFFSET 

ERROR NOISE

VOLTAGE 

RANGE FOR 

ERROR 

NUMBERS

TOTAL 

PROBABLE 

ERROR

MASS FLOW TRANSDUCER g/sec ± g/sec ± g/sec ± g/sec ± g/sec ± g/sec ± Volts ± g/sec

0.042 0.084 0.013 0.039 0.25 0.1030.168 0.337 0.052 0.108 1.00 0.3950.002 0.003 0.000 0.001 0.25 0.0040.006 0.012 0.002 0.004 1.00 0.014

INSTRUMENT DATA ACQUISITION SYSTEM TOTAL

INPUT SENSOR SPAN (CALIBRATION) ACCURACY1 ± 1.35% SPAN PERFORMANC E ± 0.173% SPAN

SCP 

LINEARITY

± 0.01% 

VOLTAGE 

RANGE

AUTORANGING

± 0.02% 

VOLTAGE 

RANGE

SCP OFFSET 

ERROR NOISE

VOLTAGE 

RANGE FOR 

ERROR 

NUMBERS

TOTAL 

PROBABLE 

ERROR

VOLUME FLOW TRANSDUCER m3/min ± m3/min ± m3/min ± m3/min ± m3/min ± m3/min ± m3/min ± Volts ± m3/min

0.000 0.000 0.000 0.000 0.25 0.0960.001 0.002 0.000 0.001 1.00 0.0960.000 0.001 0.000 0.000 0.25 0.1720.002 0.003 0.001 0.001 1.00 0.172

0.0120.022 EXH PIPE FM 0 TO 12.7 m^3/min 0.172

STM SUPPLY FM 0 TO 7.1 m^3/min 0.096

DROP INJ FM 0 TO 45 g/sec 0.00005

SUPPLY LINE FM 0 TO 1247 g/sec 0.00137

Table B.4 Error in Steam Probe Rakes Linear Position Transmitter 

INSTRUMENT DATA ACQUISITION SYSTEM

INPUT SENSOR SPAN (CALIBRATION) ACCURACY ± 1.0% SPAN

SCP 

LINEARITY

± 0.01% 

VOLTAGE 

RANGE

AUTORANGING

± 0.02% 

VOLTAGE 

RANGE

SCP OFFSET 

ERROR NOISE

VOLTAGE 

RANGE FOR 

ERROR 

NUMBERS

CHANNEL NO. POSITION TRANSDUCER mm ± mm ± mm ± mm ± mm ± mm ± Volts

0.003 0.006 0.001 0.003 0.250.012 0.024 0.004 0.008 1.00 482-489 RAKE POSITION 0 TO 88.9 mm 0.889
B-7 

Table B.5 Error in Heater Rod Bundle Input Voltage (V), Amperage (Amps), and Power (W) Measurements 

INSTRUMENT DATA ACQUISITION SYSTEM

INPUT SENSOR SPAN (CALIBRATION) ISOLATOR ACCURACY ± 0.1% SPAN

SCP 

LINEARITY

± 0.01% 

VOLTAGE 

RANGE

AUTORANGING

± 0.02% 

VOLTAGE 

RANGE

SCP OFFSET 

ERROR NOISE

VOLTAGE 

RANGE FOR 

ERROR 

NUMBERS

CHANNEL NO. VOLTAGE TRANSDUCER Volts ± V ± mV ± mV ± uV ± uV ± Volts

0.27 0.67 107.99 310.48 0.251.08 2.70 418.47 863.93 1.00

INSTRUMENT DATA ACQUISITION SYSTEM

INPUT SENSOR SPAN (CALIBRATION) SHUNT ACCURACY ± 0.1% SPAN ISOLATOR ACCURACY ± 0.1% SPAN

SCP 

LINEARITY

± 0.01% 

VOLTAGE 

RANGE

AUTORANGING

± 0.02% 

VOLTAGE 

RANGE

SCP OFFSET 

ERROR NOISE

VOLTAGE 

RANGE FOR 

ERROR 

NUMBERS

CHANNEL NO. CURRENT TRANSDUCER Amps ± A ± A ± A ± A ± A ± A ± Volts

0.40 1.01 0.16 0.47 0.251.62 4.05 0.63 1.30 1.00

INSTRUMENT DATA ACQUISITION SYSTEM

INPUT SENSOR SPAN (CALIBRATION) DAS VOLTS ACCURACY ± 0.1% SPAN DAS AMPS ACCURACY ± 0.14% SPAN

CHANNEL NO. DERIVED POWER (V*A) kWatts ± W ± W

15

1050 397 * 398 ELECTRICAL SYSTEM 0 TO 750 kWatts 750

397 ELECTRICAL SYSTEM 0 TO 10 Volts 0.01398 ELECTRICAL SYSTEM 0 TO 15000 Amps 15
B-8 

B.2 Heat Transfer Coefficient Uncertainty Analysis

The purpose of this uncertainty analysis was to estimate the confidence limits in the heat 

transfer coefficients calculated for heater rods in the RBHT Test Facility bundle test series using 

the uncertainty analysis using performed on the FLECHT-SEASET heater rods. It is believed 

that the uncertainty geometry analysis performed on the FLECHT-SEASET heater rods is 

applicable to the RBHT heater rods since the construction and materials are the same or very 

similar. 

The uncertainty analysis used the FLECHT-SEASET heat transfer coefficients calculated from 

test data, using DATARH. The sensitivity of the heat transfer coefficient to variations in the test 

data and heater rod design was also calculated by the code. This code solves an inverse heat 

conduction problem using a finite-difference technique. 

The uncertainty analysis used standard statistical treatment of independent uncertainty 

components to establish 1σ (70 percent) and 2σ (95 percent) confidence intervals on the total 

uncertainty in the heat transfer coefficient. Individual uncertainty components were obtained 

from heater rod inspection data, physical information, or professional experience and judgment. 

Each component of the total uncertainty was assumed to be independent, and of known 

variance. 

Figure B.1 Heater Rod Design. 
B-9 

The FLECHT SEASET unblocked bundle test series utilized stainless steel clad, boron nitride 

filled heater rods with coiled Kanthal wire heating elements (Figure B.1). For the RBHT test 

bundle the cladding was Inconel and not stainless steel but the remaining of the heater rod 

design was the same. The other properties were the same. In the instrumented heated rods, 

thermocouples were located at several different axial locations on the inside wall of the 

cladding. The thermocouple output was used in the DATARH code to compute the heat transfer 

coefficient. The code input requires density, specific heat, and thermal conductivity for the 

heater rod materials and geometric details of the heater coil. 

The heater rod geometric input included clad inside and outside diameters and thermocouple 

radial location. Code input from the FLECHT SEASET bundle test instruments included 

thermocouple temperature, bundle pressure, and SCR power output.

The heat transfer coefficient may be expressed as 

 ] [ , ,....... 1 2 n h = h x x x (B-7) 

where xi (i = 1, 2, . . . n) are the individual parameters that affect the heat transfer coefficient h. 

The statistical variation of calculated h about its expected value may be expressed by 

expanding the function h[x1,x2,.....xn] in a multivariable Taylor series. 

Including only first-order terms, the result is 

[ , ,..... ] [ ] { [ ]}

1

1 2 i i

x

n

i i

n x E x

x

h h x x x E h − 















∂

∂ − = =

 (B-8) 

or 

i

x

n

i i

x

x

h h Δ 















∂

∂ Δ = =1

 (B-9) 

where the derivatives are evaluated using the means of all the random variables xi (denoted by 

x ). E[h] is the expected or mean value of the function h; that is, h evaluated at the means of 

the random variables xi. Each i x i (∂h / ∂x ) Δx term also is a random variable with a mean of zero 

and a variance given by 

2 2

2

var i hi x

x i

i

x i x

h

x

x

h

 = Δ 













∂

∂ Δ = 















∂

∂

σ σ (B-10) 

where i x (∂h / ∂x ) is constant for given x . 

Assuming the i x i (∂h / ∂x ) Δx terms are independent, the mean of h becomes 
B-10 

[ ] [ ] 0

1

Δ = 















∂

∂ Δ = =

i

x

n

i i

E x

x

h E h (B-11)

and the variance of h is 

2

2

1 1

2 2

i i x

x

n

i

n

i i

h h

x

h

σ   σ σ = =

Δ Δ 















∂

∂ = = (B-12)

Approximating the i x (∂h / ∂x ) terms by i x (Δh / Δx ) , the variance becomes

2

2

1

2

i x

x

n

i i

i

h

x

h

σ  σ =

Δ 















Δ

Δ = (B-13)

A consequence of the central limit theorem in statistics is that the distribution of the uncertainty 

calculated above approaches a normal distribution. With a known distribution function, the 

confidence interval of the uncertainty can be calculated from the variance. The 1σ (70 percent) 

and 2σ (95 percent) confidence intervals are reported in this evaluation. 

These values were obtained by individually perturbing each parameter xi from its expected 

value by its estimated standard deviation in numerous runs of the DATARH code. Each 

perturbation resulted in a new value of calculated h, from which the nominal or expected value 

was subtracted to provide hi. Since in these perturbations xi was assumed to be equal to i σ x , 

the variance can be evaluated by simply summing the squares of the resultant hi terms: 

=

Δ = Δ

n

i

h h i

1

2 2 σ (B-14) 

Positive and negative hi terms ( , ) + − Δhi Δhi were obtained by perturbing each xi both above and 

below its expected value. They are indicative of the heat transfer coefficient’s sensitivity to 

uncertainty in each parameter, and were statistically combined to provide bother upper and 

lower uncertainty bands on calculated h. Differences in the and for each + Δhi and − Δhi are due 

to nonlinearities in the function h [x1, x2, . . . xn]. 

Uncertainty in the heat transfer coefficient, h, calculated by the DATARH code stems from the 

following factors: 

• Uncertainty in the measured test parameters input to the program 

• Uncertainty due to manufacturing tolerances on heater rod dimensions and 

instrumentation location 

• Material property uncertainties 

Measured test parameters that are input to DATARH are bundle power, pressure, and clad 

inside temperature. 
B-11 

The uncertainty in the measured parameters is combined with other sources of uncertainty by 

summing the variance of each uncertainty component. For the test instruments, the instrument 

uncertainty was assumed to be uniformly distributed over the uncertainty interval. The variance 

of a uniformly distributed random variable over the interval -∞ < x < ∞ is 2⁄3. The total 

instrument uncertainty consists of uncertainty in the sensor, in signal conditioning equipment, 

and in recording the signal. The variance of each of these components was calculated as 

described above and summed to get the total variance of the instrument uncertainty. 

Transducer uncertainty is normally dominant, and thus total uncertainty and transducer 

uncertainty will be very similar. 

The standard deviation (that is, the positive square root of the variance) and maximum 

uncertainty for each data path are shown in Tables B.1 through B.5. The maximum uncertainty 

was calculated by summing the maximum uncertainty of all contributors to the total instrument 

uncertainty. 

Manufacturing tolerances on rod dimensions and instrumentation location also contribute to 

uncertainty in the calculated heat transfer coefficient h. Heater coil dimensions, clad inside and 

outside diameters, and thermocouple locations are incorporated in the DATARH geometric 

heater rod model, because they are possible contributors to uncertainty in h. Uncertainty in the 

thermocouple radial location was estimated from X-ray inspection of actual heater rods. Clad 

outside diameter uncertainty was obtained from the rod inspection data. Uncertainty in clad 

inside diameter was estimated by combining the uncertainty in clad outside diameter with the 

uncertainty in clad thickness. 

Axial power is also a factor. In FLECHT SEASET heater rods, the number of heater coil turns 

per in (coil spacing) is variable (Figure B.1); this changes the length of heater wire per unit 

length of heater rod. From the X-ray radiographs of the heater rods, the geometry of the axial 

power steps was determined. Similar approach has been used for the RBHT heater rods. 

The rod inspection data do not reflect any variation in the diameter of the Kanthal heater wire. 

The wire diameter was nominally 0.10 cm (0.040 in), and small variations in diameter were 

beyond the resolution of the radiograph. To estimate the uncertainty due to wire diameter 

variation, the assumption was made that the local variation in wire resistance due to the wire 

cross-sectional area variation could be approximated from the variation in heater rod resistance 

between rods. 

Uncertainty in the physical properties of the material in the heater rods was based largely on 

engineering judgment. The boron nitride density uncertainty was based on a sample of five 

measurements from sections of heater rods that were destructively analyzed. 

The input parameters for power factor (Plocal/Paverage) determination are local step length, total 

heated length, local step length coil resistance, and total heated length coil resistance. An 

analysis identical to that discussed was performed for this calculation, varying the input 

parameters by the estimated standard deviations. Estimated power factor parameter 

uncertainties are show in Table B.6, and the power factor uncertainty analysis in Table B.7. 
B-12 

Table B.6 Uncertainty of Power 

Table B.7 summarizes the certainties of all the parameters used by DATARH to calculate the 

FLECHT SEASET heat transfer coefficient. These uncertainties were evaluated at the 1σ (70 

percent confidence) level. The uncertainties in Table B.8 for the heater rod material properties 

are expected to be similar as the same uncertainties used for the RBHT heater rods since the 

design and materials are similar. 

Other sources of uncertainties that could lead to increased uncertainty in the value of h were 

reviewed; however, for the most part, they were of relatively minor importance and their 

absence in this analysis would not be significant. Those other factors were as follows: 

• Induction and skin effects - These effects of high-frequency components of the 

chopped ac power were neglected. 

• Wire effective length - Analytically, the effective length for a tightly coiled wire is less 

than the length based on the helix mean radius (which is used in DATARH). However, 

this source of uncertainty is the same for each wire and will cancel out in the relative 

power calculation. Therefore, such a correction was not required. 

• Electrical resistivity variation with temperature at rod quench - Changes in rod 

temperature distribution will affect the local P/Pavg. For example, if half the rod is 

quenched, resistivity in the upper half could be as much as four percent greater than that 

in the lower half, and power would be redistributed within the rod. Since there was no 

method by which this could be accounted for proportionately, this effect was ignored. 

• Kanthal heater helix position - The heater coil may be slightly off center in the rod. 

This effect was analyzed by varying the coil diameter; however, no coil displacement 

was examined. 
B-13 

• Thermocouple axial location - The thermocouples were located at different positions 

along the length of the rod. Any axial conduction in the heater rod in the vicinity of the 

thermocouples was assumed to be small since the axial profile is linear and the rate of 

change of power over the bottom 2.74 m (9 ft) of the heater rod is also small. 

Table B.7 Thermocouple Power Factor Uncertainty Analysis 
B-14 

Table B.8 Uncertainties Affecting the Heat Transfer Coefficient Calculations 
B-15 

Table B.8 Uncertainties Affecting the Heat Transfer Coefficient Calculations (Continued) 

The uncertainty analysis was performed for FLECHT-SEASET test 31504 with the following 

nominal initial conditions: 

 Pressure 0.28 MPa (40 psia) 

 Initial Clad Temperature 871 degrees C (1600 degrees F) 

 Rod Peak Power 2.3 kW/m (0.7 kW/ft) 

 Flooding Rate 25 mm/s (1.0 in/s) 

 Inlet Subcooling 60 degrees C (140 degrees F) 

 Radial Power Uniform 

 Housing Temperature Tsat

These test conditions are similar to the low flooding rate RBHT tests. 
B-16 

The analysis was performed on the heat transfer coefficient calculated for the hot rod 8K at the 

1.98 m (78 in) elevation. The calculated value of the heat transfer coefficient from rod 8K was 

obtained with the best-estimate values of all the parameters in Table B-8. Both positive and 

negative values of hi were obtained from subsequent DATARH calculations for which the 

parameters given in Table B.8 were varied. The calculated positive and negative values of hi

are listed in Table B.9 as a function of time. They are indicative of the heat transfer coefficient 

sensitivity for each parameter. The various values of + Δhi and − Δhi are statistically combined in 

Table B.10 and the resulting calculated h values with the estimated 95 percent confidence 

bands (2σ) are shown in Table B.11. 

Examination of the hi values in Table B.9 shows that the measured power, rod outside diameter, 

clad thickness, and power step factor had the largest effects on the calculated heat transfer 

coefficient. Other parameters such as the rod properties (except the boron nitride density), rod 

temperature, and system pressure clearly had second-order effects on the accuracy of the 

calculated heat transfer. 

The method used in this analysis presupposes that the process is linear; higher-order terms in 

the Taylor series expansion [Equation (B-6)] were neglected. If the method is linear, then the hi

values would be of equal magnitude but opposite sign. However, as the hi values listed in Table 

B.9 indicate, the inverse conduction scheme is not a linear equation and hi values can have 

different magnitudes if the deviation is taken in either the positive or negative direction from the 

normal value. Therefore, when the upper and lower bands are calculated as in Table B.10, 

these bands will not have the same magnitude. One method of compensating for the effect of 

nonlinearity is to simply average each deviation, both positive and negative values, and obtain 

an averaged deviation at each time step. This will result in a centered confidence band about 

the estimated heat transfer coefficient data. The calculations for this approach are given in 

Table B.12. 

Figure B.2, which shows the calculated heat transfer coefficient (h) with the 95 percent 

confidence limits, indicates that the largest uncertainty in h is early in the transient, particularly 

at the beginning of reflood. Figure B.3 shows the relative uncertainty for the upper 95 percent 

confidence band as plotted from Table B.10. This indicates that the relative uncertainty quickly 

decreased to approximately 10 percent by 30 s for this test. 
B-17 

Table B.9 Parameter Sensitivities 
B-18 

Table B.9 Parameter Sensitivities (Continued) 
B-19 

Table B.9 Parameter Sensitivities (Continued) 
B-20 

Table B.10 Standard Deviations 
B-21 

Table B.11 Calculated h and 95 Percent Confidence Limits Versus Time 

 
B-22 

Table B.12 Calculated h and 95 Percent Confidence Limits Versus Time 

Using (σh)avg Values 
B-23 

Figure B.2 Rod Heat Transfer Coefficient as a Function of Time 

(95 Percent Confidence Limits). 
B-24 

Figure B.3 Relative Uncertainty in Heat Transfer Coefficient as a Function of Time. 

B.3 References

1. Loftus, M. J., Hochreiter, L. E., Conwig, C. E., Dodge, C., Tong, A., Rosal, E. R., 

Valkovic, M. M., and Wong, S., “PWR FLECHT-SEASET Unblocked Bundle, Forced and 

Gravity Reflood Task Data Report,” NUREG/CR-1532, Volume 1, June 1980. 
BIBLIOGRAPHIC DATA SHEET

(See instructions on the reverse)

NRC FORM 335

(9-2004)

NRCMD 3.7

U.S. NUCLEAR REGULATORY COMMISSION 1. REPORT NUMBER

 (Assigned by NRC, Add Vol., Supp., Rev.,

 and Addendum Numbers, if any.)

NUREG/CR-6980

3. DATE REPORT PUBLISHED

MONTH

April

YEAR

2012

4. FIN OR GRANT NUMBER

N6154

2. TITLE AND SUBTITLE

RBHT Reflood Heat Transfer Experiments Data and Analysis

5. AUTHOR(S)

L.E. Hochreiter, F-B. Cheung, T.F. Lin, S. Ergun, A. Sridharan, A. Ireland, E.R. Rosal

6. TYPE OF REPORT

Technical

7. PERIOD COVERED (Inclusive Dates)

Nov 1997 - Feb 2003

8. PERFORMING ORGANIZATION - NAME AND ADDRESS (If NRC, provide Division, Office or Region, U.S. Nuclear Regulatory Commission, and mailing address; if contractor,

The Pennsylvania State University

9. SPONSORING ORGANIZATION - NAME AND ADDRESS (If NRC, type "Same as above"; if contractor, provide NRC Division, Office or Region, U.S. Nuclear Regulatory Commission, 

Division of Systems Analysis

provide name and mailing address.)

and mailing address.)

10. SUPPLEMENTARY NOTES

K. Tien, NRC Project Manager

11. ABSTRACT (200 words or less)

A total of 25 valid bottom reflood heat transfer experiments have been performed in the Pennsylvania State University/U.S.

Nuclear Regulatory Commission Rod Bundle Heat Transfer (RBHT) Test Facility to examine the effects of both dispersed flow

film boiling and inverted annular film boiling in a rod bundle geometry. The RBHT Test Facility has a full length, 3.66 m (12 ft),

7x7 rod array with typical pressurized water reactor rod diameters of 9.49 mm (0.374 in) and a rod pitch of 12.59 mm (0.496 in). 

The heater rods had a top skewed power shape with a peak to average power of 1.5 at the 2.77 m (9.08 ft) elevation. The

ranges of conditions for the experiments were pressures from 137.9 to 413.7 kPa (20 to 60 psia), flooding rates from 0.0147 to

0.1524 m/s (0.58 to 6 in/s), and initial temperatures from 760 to 871 degrees C (1400 to 1600 degrees F), inlet subcooling from

11.1 to 83.33 degrees C (20 to 150 degrees F), and peak powers of 1.32 to 2.31 kW/m (0.4 to 0.7 kW/ft). The experiments were

performed using a constant power rather than simulating the reactor decay power. The use of constant bundle power extended

the reflood transient several hundred seconds and resulted in quasi-steady film boiling over the majority of the bundle length.

12. KEY WORDS/DESCRIPTORS (List words or phrases that will assist researchers in locating the report.)

dispersed flow film boiling, heat transfer enhancement, mixing vane, quench front progression, reactor

safety, reactor systems codes, reflood heat transfer, rod bundle, spacer grid, thermal hydraulics 14. SECURITY CLASSIFICATION

13. AVAILABILITY STATEMENT

unlimited

(This Page)

unclassified

(This Report)

unclassified

15. NUMBER OF PAGES

16. PRICE

NRC FORM 335 (9-2004) PRINTED ON RECYCLED PAPER

University Park, PA 16802

Office of Nuclear Regulatory Research

U.S. Nuclear Regulatory Commission

Washington, DC 20555-0001


UNITED STATES 

NUCLEAR REGULATORY COMMISSION

WASHINGTON, DC 20555-0001

--------------------

OFFICIAL BUSINESS
NUREG/CR-6980 RBHT Reflood Heat Transfer Experiments Data and Analysis