o "!•— >

AE-1062nd rev. ed.

"J -Ö Measurements of Void Fractions for Flow

of Boiling Heavy Water in a

Vertical Round Duct

S. Z. Rouhani and K. M. Becker

AKTIEBOLAGET ATOMENERGI

STUDSVIK, NYKÖPING 1963

AE-106

2nd rev. ed.

MEASUREMENTS OF VOID FRACTIONS FOR FLOW OF BOILING

HEAVY WATER .IN A VERTICAL ROUND DUCT

(Revised edition)

S Zia Rouhani and Kurt M Becker

Summary:

The present report deals with measurements of void fractions

for flow of boiling heavy water in a vertical round duct with 6. 10 iTim

inner diameter and a heated length of 2500 mm. The following ranges

of variables were studied and 149 void fraction measurements were

obtained.

Pressure 7 < p < 60 bars

Steam quality 0 < x < 0. 38

Surface heat flux 38 < q/A < 1 20 W/cm2

Mass velocity 650 < m/F < 2050 kg/m s

Void fraction 0. 24 < <* < 0. 88

The measurements were performed by means of a method,

which is based on the (v, n) reaction, occurring when heavy water

is irradiated by gamma rays.

The results are presented in diagrams, where the void frac-

tions and the slip ratios are plotted against the steam quality with

the pressure as a parameter. The data have been correlated by

curves, and the scatter of the data around the curves is less than

- 5 per cent.

Printed and distributed in September !9b3.

LIST OF CONTENTS

Page

1. 0 Preface to the Revised Edition 3

1.1. Introduction 3

2.0. Description of Apparatus 5

2. 1. Test section 5

2.2. Instrumentation 6

3. 0. .Method of Testing and Range of Variables 9

4. 0o Results and Discussions . 10 ,

Acknowledgements 1 1

References 12

Tables 1 3

Figures . 1 7

- 3

1. 0. Preface to the Revised Edition

The experimental data on void volume fractions for flow of

boiling heavy water, given in AE-106 were released for publica-

tion before a second series of measurements with improved in-

strumentation of the loop were obtained. In the light of the new

measurements it has become clear that due to the lack of better

ways and means of measuring the background and actual neutron

count rates in the first series of experiments the values of void

volume fractions obtained at pressures of 7 to 40 bars were about

1 0 % (net void) less than the actual values. But the measured void

fractions at pressures of about 50 and 60 bars were fortunately made

with the improved instrumentation and therefore those data are free

of this systematic error.

It was then considered necessary to make this revised edition

to replace the previous report and also show the orderly changes

in variations of the void volume fractions with pressure for con-

stant values of steam quality.

In this edition a short description of the void measuring system

is included and the improved manner of background measurement is

also described. A major part of the Table I is changed and figures

6, 7, 8, 9, 10, 14, and 15 are renewed. Finally a new reference is

added for those who may find an interest in the details of the loop

and its instrumentation.

1.1. Introduction

The problem of predicting void volumes for flow of steam, wa-

ter mixtures In vertical channels is very important for the designer

of boiling nuclear reactors.

A knowledge of the void volume is needed for the determina-

tion of mean fluid density, acceleration and hydrostatic pressure

drops and also for the computation of reactivity in water-cooled

reactors. Furthermore, for the establishment of two-phase flow

.. 4 -

frictional pressure drop correlations, accurate knowledge about

the void fraction is also desirable. The void fraction is defined by

the equation

a= A /A (1)v

where A is the cross-section of the channel and A is the timev

average of that part of the cross-section which is occupied by-

vapor.

During recent years a large amount of experimental infor-

mation concerning void fractions has appeared in published works.

Most of these measurements were obtained by means of the 7-atte-

nuation method. During the year 1960 two theoretical methods for pre-

dicting void volume fractions were also presented by Levy (i) and

Bankoff (2). The former paper also contained references to the

most important experimental studies in the field.

The purpose of the present report is to give the results of

void measurements obtained for the flow of heavy water in a 6 mm

inner diameter duct of 2500 mm heated length.

The measurements were performed by means of a new method.

This method is based on the (y, n) reaction, which occurs when heavy

water is irradiated by gamma rays* The details and principles of

this method are given in another paper (3).

Since the present report only covers the first phase of the in-

vestigation and measurements in other geometries are in progress

in our laboratory, a detailed discussion of the data in relation to the

information in published works on the subject will be included not in

this, but in a final report on completion of the investigation.

- 5 -

2. 0. Description of Apparatus

Because the method employed made it necessary to use heavy

water as the working medium, some special requirements in construc-

ting the loop became apparent. The volume of the loop had to be as

small as possible, and all of its components had to be made of stain-

less steel. To keep the water clean, an ion exchanger with its cooler

and heat exchangers had also to be included as a part of the loop.

Figure 1 shows the flow diagram for the loop and in figure 2 a

photograph of the loop is reproduced.

Because the available circulating pump delivered a very large

flow rate in comparison with the flow rate needed for the experiments,

it was necessary to make a by-pass for the major part of the flow.

The by-pass was made as a cooler to remove the excess heat which

developed in the fluid circulating through the pump. This arrangement

had also the advantage of saving the pump and the turboflowmeter from

being subjected to high working temperatures.

In addition to the pump and the ion exchanger, the other impor-

tant parts of the loop were the preheater, the test section, the water-

cooled condenser, the pressurizer and the flowmeters.

The loop was pressurized with compressed air that was supplied

to the top of the pressurizer. The pressurizer acted also as an accu-

mulator to dampen pressure variations in the condenser. In order to

release excess pressures, a valve was connected to the top of the

condenser.

2. 1. Test section

The test section, which is shown in figure 3, was made of a

stainless steel tube with a 6 mm inside diameter and 2 mm wall

thickness. The heated length of the tube was 2500 mm.

- 6 -

Three silver plated copper rings, 15 mm outside diameter and

1 0 mm long, were brazed on the tube at three points, one at the cen-

ter and one at each end. The copper electrodes, supplying the power

to the test section, were clamped around the copper rings. The power

was obtained,from a direct current generator» The two end electrodes

were connected to one pole on the generator, and the central electrode

to the other pole. With this arrangement, it was not necessary to in-

sulate the test section from the rest of the loop in order to prevent

the loss of electric power to the other parts of the loop. .

Four pressure taps, consisting of 4 mm inner diameter stain-

less steel tubes were welded around 0. 8 mm diameter holes on the

test section. The positions of the pressure taps are shown in figure 3.

The void fractions were measured at a fixed height of 2300 mm

above the starting point of the heated section. This point, which in

this report is called the test point is indicated in figure 3. Two

pressure taps, 2 and 3, were positioned at a distance of 50 mm on

each side of the test point.

The void measurements were performed by irradiating a sector

of the test section by hard gamma-rays, obtained from Na-24, and

counting the neutrons produced as a result of the D (v, n) H reaction.

The irradiated sector extended 1 0 mm on each side of the test point,

2. 2. Instrumentation

.The following quantities were measured

a) Mass flow rate

b) Power input to the test section from the inlet to the testpoint, as well as the power input to an arbitrary lengtharound the test point

c) Pressure at the test point

d) Pressure drop across a short length around the test point,P 2 - P 3

_ 7 -

e) Fluid temperatures at the inlet and the outlet of the testsection

f) Neutron count rates.

In figure 4 is shown the scheme for connecting the instruments

necessary to measure the quantities named in (a) to (e), and figure 5

shows a view of the instrumentation panels.

For part (a), a turboflowmeter (Pottermeter) was used. The

cation of this instrument sho-

rn the whole range of application.

calibration of this instrument showed an error less than - 0. 7 per cent

For part (b) separate amperemeters were used for the two parts

of the test section. Voltage measurements were made over the lower

half of the test section, over the sector between the middle electrode

and the test point and over a length of about 500 mm around the test

point. The instruments used for the power measurements were cali-

brated and sh

scale values.

brated and showed an error of less than - 0 . 2 per cent of their full

For part (c) a precision gauge was connected with the pressure

tap placed 50 mm above the test point (p.). The reading error of this

gauge was less than - 0. I kg/cm . To obtain the absolute pressure

at the test point, the barometric pressure as well as one half of the

pressure drop between p~ and p_ were added to the gauge readings.

For part (d) a glass U-tube filled with mercury was first used,

but for operations above 40 kg/cm a mechanical gauge was later on

used instead.

For part (e) copper-constantan thermocouples were used. The

thermocouples were mounted in wells 150 mm deep and with a 3 mm

inside diameter.

For part (f) which consisted of void measurement by the (y, n)

reaction, a system of BF ne '̂.tron detectors with appurtenant electro-

nics were employed. Concerning the void measuring technique we

refer to the detailed description in reference 3. But the system will

be briefly described in the following.

A bank of 14 BF» counters embedded in paraffine were connected

in parallel to a source of high voltage {+ 2000 V) and the signals re-

sulting from the detectors were led to a common preamplifier. The

output of the preamplifier was fed to a main amplifier and the re-

sulting pulses were filtered through a discriminator and sent to a

count rate meter.

The presence of a noticable background (about 1 0 % of the total

neutron count rates) was observed in neutron measurements. This

was mainly due to the heavy water contained in the pressure taps

close to the test point (near the source of gamma-rays) and the pile-up

of the gamma pulses in the detectors. To these could be added the

effect of the gamma-rays on the deuterium contents of the paraffine

and the cooling water around the detectors. Measurements of the back-

ground count rates had shown a continuous decay of the exponential

type. But, the rate of decay was much faster than that of the gamma-

source.

It was therefore necessary and sufficient to check the background

at time intervals of about two hours to make a curve of its variations

with time during the whole experiment. The background count rates

could easily be calculated from two neutron count rates, one obtained with

no void at all (full channel) and the other with a known void fraction.

To introduce a known void fraction an empty metallic tube was lowered

down into the test section. This tube was normally pulled out by an

electro-magnet and kept by the magnet in a long vertical sleeve on

top of the test section. A more detailed description of these components

and their connections is given in ref. (4).

- 9 -

3.0. Method of Testing and Range of Variables

Before starting a series of runs the instruments were always

inspected, and heat balances relating the electric heat input to the

enthalpy increase of water were taken. The error of the heat balances

was always less than - 3 per cent. The activated gamma ray source

was then mounted on the loop and the neutron count rates for back-

ground computation were recorded. After raising the pressure to the

desired level, the power was turned on for the test section and the

flow rate was gradually decreased until the outlet thermocouple

showed the boiling temperature. A series of runs was then started.

In each series of runs the pressure as well as the heat flux were

kept constant and for each run of the series the flow rate was slightly

reduced. Following every change in the flow rate, ample time was

given for the flow to reach steady state before the instrument readings

were recorded.

As the flow rate is decreased, the steam quality and the void

fraction at the test point increase. The present report deals only

with measurements in the net boiling regime. However, subcooled

boiling can be obtained at the test point by adjusting the flow rate and

the heat flux so that inception of boiling occurs just upstream of the

test point. Measurements of void fractions in the sub-cooled boiling

regime will be presented later in a separate report.

Several heat fluxes were applied at each pressure and the

following ranges of parameters were covered during the investi-

gation.

Pressure p 7, 10, 20, 30, 40, 50 and 60 kg/cm

Heat flux q/A 38, 50, 64, 90 and 120 W/cm2

Steam quality x 0 -0 .38

Mass velocity m/F 650 - 2050 kg/m s

Void fraction a 0. 24 - 0. 88

Slip ratio s 0 - 6. 0

- 10 -

From, the instrument readings the above-mentioned parameters

were computed, as well as the phase velocity difference, the pressure

gradient, the saturation pressure and temperature3 the vapor and

liquid properties at the test point and the liquid properties at the in-

let. The computation procedures are given in reference (4), and the

results of the computations are given in table I. Altogether, 148 runs

were made.

4. 0. Results and Discussions

The experimental results are shown in figures 6 to 12, where

for a given pressure, the slip ratio and the void fraction are plotted

against the steam quality. The scatter of the data around the correla-

ting curves is less than - 5 per cent, indicating a very good repro-

ducibility of the measurements. In considering the accuracy of the

measurements one should also note that a substantial part of the

scatter is due to small differences in the pressure existing during

the different runs belonging to one series.

The data show that both the slip ratio and the void fraction in-

crease with increasing steam quality, and that the surface heat flux

has a negligible effect on the results. Since data obtained at different

heat fluxes, but constant steam quality, cover different mass velocities,

one may also conclude that in the ranges investigated, the mass flow

rate has a negligible effect on the void fraction and the slip ratio. The

latter quantities may therefore be expressed by the functions

a = a (x, p) (2)

s = s (x, p) (3)

The theoretical results by .Levy (1) and Bankoff (2) are also in-

dicated in figures 6 to 12. Neither on of these theoretical results seem

to agree satisfactorily with our experimental data.

Predictions based on Bankoff s ' theory undershopts the whole

data in all ranges.

11 -

Considering Levy's predictions the agreement is only satisfactory

for steam qualities higher than 35 per cent.

When x approaches zero, the void fractions obtained from the

theories also approach zero, while\ the present measurements indicate

values between 0. 24 and _0. SO.depending on the pressure. The reason

for this rather high difference is that the true steam quality at the

point of x = 0 in the diagrams differs from zero, owing to the effects '

of subcooled boiling. Figure 13 shows schematically the true steam

quality distribution along the channel in comparison with the distri-

bution computed from the heat balance.

Distributions of this type have earlier been verified theoreti-

cally and experimentally by several authors, for instance Griffith

et.al. (5). Measurements obtained in the sub-cooled region will be

presented and discussed in a separate report.

The effect of pressure on slip ratio and void fraction may be

observed in figure 14, where the' data presented earlier are summa-

rized. For the case of slip ratio the pressure effect is further de-

monstrated in figure 15, which shows that the slip ratio decreases

with increasing pressure. This is in agreement with the fact that

one expects the slip ratio to reach unity at the critical pressure.

Acknowledgements

The authors "wish to acknowledge the important contributions and

advise received from Mr Jan E Flinta in the development of the experi-

mental rechnique as well as during the course of the experimental in-

vestigation.

The authors also wish to express their appreciation to Mr Arne

Lundberg for his skilled work in constructing, maintaining and opera-

ting the apparatus, to Mr Gunnar Hernborg for participating in ob-

taining the data and finally to Mr Rolf Lindh who made the program

for the digital computer and took care of the computations.

12 -

References

1 . LEVY SSteam Slip - Theoretical Prediction from Momentum ModelJournal of Heat Transfer (May, 1960 pp. 1 13-124).

2. BANKOFF S GA Variable Density single Fluid Model for Two-Phase withParticular Reference to Steam-Water FlowJournal of Pleat Transfer, November 1960, pp. 265-272.

3. ROD HANI S ZVoid Measurement by the (v, n) ReactionAE-83 (1962).

4. ROUHANI S ZDescription of the Loop Soraya - the Heavy Water Loop forVoid Measurements.AB Atomenergi, RPL-669 (Stockholm, 1963).

5. ROUHANI S ZComputation Program for the Loop Saraya.AB Atomenergi, RPL-H4-437 (Stockholm, 1962).

6. GRIFFITH et. al.Void Volumes in Subcooled Boiling SystemsTrans. ASME Paper No 58-HT-19.

SR & KB/EL

Table \ Experimental Data

Ron

No

12345

678910

1112131415

1617181920

2122232425

2627282930

3132333435

3637383940

4142434445

4647484950

5152535455

5657585960

Phars

6.89

6.89

6.89

6.90

6.95

7.00

7.00

6.90

6.91

6.86

9.84

9.84

9.969.91

9.93

9.97

9.99

19.53

19.53

19.53

19.53

19.5319.53

19.5319.53

19.53

19.59

19.59

19.53

19.60

19.6019.53

19.5319.53

19.53

19.53

19.53

19.5319.53

19.53

19.53

29.46

29.46

29.4629.41

29.46

29.47

29.4729.4729.47

29.47

29.4229.47

27.48

29.53

29.48

29.48

29.4829.58

29.48

q/A

W/cm s

39,6

39.6

39.6

39.6

39.6

39.6

39.6

36.5

36.5

36.5

42.11

42.11

63.12

62.24

62.24

62.09

61.69

49.34

49.49

49.34

49.49

49.49

49.49

49.49

49.49

49.3560.18

62.70

61.75

62.62

62.54

61.91

61.8361.51

61.51

61.51

61.3561.3561.35

61.35

61.35

90.4591.21

91.52

91.30

91.4391.3091.21

91.08

91.30

91.30

91.40

91.08

91.18

91.21

91.08

91.1191.18

91.2190.99

m/Fkg/in2 s

1009

996935918895

875846799741661

987963199319641954

18911634

961941936

909886854813766

7191248

1232

1200

1219

1212 •

1174

1141

1116

1090

1050

994922875853

82915981573

1550

1535

14921451

14391423

1416

1379

1342

1307

1280

1263

1255

1227

11951164

1158

Y

0.00157

0.00612

0.01319

0.0191

0.0283

0.03159

0.04247

0.06307

0.09343

0.1375

0.00523

0.01333

0.00393

0.00657

0.00901

0.01624

0.06089

0.00003

0.01194

0.01246

0.02788

0.04123

0.060010.08494

0.1166

0.1525

0.00021

0.005720.00902

0.00928

0.012240.01914

0.03297

0.045050.05543

0.07288

0.1005

0.14230.1732

0.1911

0.2072

0.00083

0.01561

0.026960.03252

0.04754

0.06163

0.06225

0.06617

0.07461

0.09241

0.10810.1214

0.1338

0.1392

0.1467

0.1587

0.1765

0.1929

0.1988

0.5202

0.5945

0.6526

0.6910

0.7304

0.7576

0.7849

0.8417

0.8693

0.9104

0.6624

0.7007

0.5310

0.59360.6078

0.6667

0.7922

0.3351

0.53480.5414

0.6280

0.66910.7168

0.7553

0.7912

0.9698

0.4321

0.5131

0.5679

0.5379

0.55390.6062

0.6528

0.6788

0.7068

0.73280.7764

0.82050.83810.8514

0.8629

0.41660.5270

0.5823

0.5997

0.6656

0.70160.7064

0.7136

•0.7316

0.76680.7694

0.7882

0.8108

0.8254

0.8211

0.8402

0.8569

0.86560.8691

s

0.37

1.061.79

2.242.44

2.90

3.01

3.18

3.893.97

0.47

1.01

0.600.79

1.02

1.43

2.94

0.00

0.910.92

1.47

1.84

2.18

2.603.01

0.490.02

0.47

0.60

0.69

0.861.101.57

1.93

2.10

2.48

2.78

3.14

3.50

3.56

3.59

0.060.79

1.11

1.25

1.40

1.551.54

1.58

1.65

1.722.02

2.07

2.00

1.90

2.08

2.00

1.99

2.06

2.08

Run

No

6162636465

6667686970

7172737475

7677787980

8182838485

8687888990

9192939495

96979899100

101102103104105

106107108109110

111112113114115

116117118119120

Pbars

29.4929.4929.4929.4939.21

39.2639.2639.2139.1639.26

39.1739.2639.2639.1739.36

39.2739.2739.2739.2739.27

39.2839.2839.2839.2839.28

49.0649.0649.0649.0649.06

49.0749.0749.0749.0748.68

48.6848.6848.6848.6848.68

48.6848.6849.0649.0648.77

49.0649.2649.0748.9748.77

49.0748.9749.0748.9748.68

49.1748.8848.9749.0748.98

q/A

W/cm 8

91.2191.3491.3091.3090.36

89.0590.4290.3390.2490.24

89.7490.0589.6189.3989.61

90.2490.3690.6890.3390.58

90.7790.5290.2090.4690.55

90.1091.0690.8790.9790.68

90.9791.2590.2991.45

124.5

124.5124.5124.3123.9123.9

123.8123.593.0092.6192.71

92.2292.1291.9391.8391.83

91.4591.5491.8391.9391.83

92.2292.51125.3125.2125.0

m/Fkg/m2 s

11271092106310111463

14251419141013901376

13641346132213021278

12271208119211681150

11131082106510441010

13991400139613801352

13501335130212972030

20182002198419661954

19141902143013831369

13521323130112841257

11921190113111011070

987874193919211901

x

0J22010.24090.25990.300000.00079

0.009700.020390.023570.034330.03781

0.045420.052870.061330.069610.07977

0.11740.13010.13940.15360.1651

0.18960.21100.22240.23480.2658

0.005530.010950.012700.020240.03270

0.037100.046250.057450.067020.00262

0.007640.011450.015290.019010.02365

0.035470.043540.004840.025420.03419

0.037620.052480.062470.071040.08573

0.12450.12480.16700.188-50.2163

0.28780.41080.017060.024640.03410

0.88400.90000.90310.92640.3732

0.41040.48190.50010.52820.5623

0.58290.62000.64730.66590.6819

0.73930.75260.77100.78400.8035

0.81570.83810.84710.85160.8742

0.36090.41390.42630.48380.5083

0.52780.54620.57740.61150.3481

0.36230.38390.40180.41990.4384

0.48140.51080.34770.45840.4774

0.51320.56240.58140.60550.6455

0.73180.73560.77990.79520.8252

0.85470.91790.41820.43710.4859

s

2.061.962.091.890.05

0.570.900.971.281.23

1.371.381.431.521.62

1.891.981.942.011.95

2.132.082.082.152.10

0.310.490.540.691.02

1.071.251.391.420.15

0.430.580.730.840.97

1.241.370.280.961.21

1.151.341.491.551.61

1.621.601.761.871.84

2.131.950.751.011.17

Run

No

121122123124155

126127128129130

131132133134135

136137138139140

141142143144145

146147148149

Pbars

48.8848.8848.9848.8848.98

48.8959.2658.7759.1759.26

59.2659.3759.3759.5759.57

59.4759.3759.4759.3759.18

59.0858.9858.9858.9858.98

58.9958.9958.9959.17

q/A

W/cm2

124.7124.5124.2124.2123.5

123.094.1794.2794.2794.56

93.2993.3993.39

122.3121.7

121.6121.3121.3120.8120.7

130.4120.3119.8119.5119.7

120.1130.3120.4119.9

m/Fkg/ra2 s

18841863182517951749

16471380134212921248

11971116105417091682

16581634160215811559

15371526149914791454

1434138813601832

x

0.040480.046520.057680.069760.08440

0.12580.003620.031580.059000.08865

0.11110.17060.22300.066870.07631

0.085070.095230.10800.11630.1276

0.12560.14010.15150.16030.1781

0.19160.22200.23930.00072

0.48640.50520.55050.59610.6281

0.69640.29390.41200.49430.5735

0.61090.70210.74750.51590.5322

0.55270.57360.61050.62160.6512

0.664.20.66790.68690.69630.7158

0.73000.75530.77070.2845

s

1.391.491.561.591.70

1.960.221.161.591.79

1.972.152.391.651.78

1.851.931.901.981.94

1.972.012.022,072.14

2.182.302.330.04

SAFETY VJLVE

V / / / / / / / / / / / ////////////SS / /

FIG.1. FLOW DIAGRAM

Fig. 2. Apparatus.

COPPERELECTRODE

TEST POINT

COPPERELECTRODE

ooCO

o*o

in" PRESSURE TAP NO.

ooöo

PRESSURE TAP NO. 3

PRESSURE TAP NO. 2

6.10MM INNERDIAMETERTEST SECTION

oCO

COPPER ELECTRODE

O

aCOI—COLU

OLL

. PRESSURE TAP NO. T

o.

-- — TO THE CONDENSER

PRESSURE TAP NO. k

ELECTRODE

TO U-TUBEFLOW MEASURfNG

TUBE

TO SCALER

11POTTERMETER

FIG. 4. INSTRUMENTATION SCHEME

Fig. 5. Instrumentation Panels,

10 p= 6.93 i 0.07 bor

in

o

ia.en

o q|A»38.1 t 1.6 w|cm2

0.05 0.10 0.15 0.20 0.25 0.30 Q35 x

LEGEND

LEVY (REF. 1)

BANKOFF (REF. 2)

« PRESENT RESULTS

0.05 0.10 0.15 0.20 0.25 0.30STEAM QUALITY x

0.35

FIG. 6. MEASURED SLIP RATIOS AND VOID FRACTIONS.

10

8

6

a: *G.

tn 2

p = 495 4 0.05 bar

q|A = 62.4 ± 0.7 wjcm2

o;os 0.10 0.15 0.20 0.25 0.30 0.35 x

1.0 r

0.8

z 0.62o<0.4u.So 0.2

LEGEND

LEVY (REE1)

BANKOFF (REF. 2)

— PRESENT RESULTS

0 0.05 0.10 0.15 0.20

FIG.7 MEASURED SLIP RATIOS AND VOID FRACTIONS

0.25 0.30 0.35STEAM QUALITY, x

10

8

6

i-J 2

p = 19.60 + 0.30 bar

v q|A = 49.A± 0.2 w|cm2

o qJA = 62.0 ±0.7 w|cm2

0.05 0.10 0.15 0.20 0.25 0.30 0.35 x

1.0 r

0.8

§0.6O<a:

o

0.2

LEGEND

LEVY (REF1)

BANKOFF (RER2)

PRESENT RESULTS

0.05 0.10 0.15 0.20 0.25 0.30STEAM QUALITY, x

0.35

FIG. 8 MEASURED SLIP RATIOS AND VOID FRACTIONS

10

i*

p =29.49 ± 0.09 bar

oqJA=91.1 i 0.7 W|cm2

a-

0.05 0.10 0.15 0.20 0.25 0.30 0.35

1.0r

LEGEND

- LEVY (REF.1)

- BANKOFF (REF. 2)

PRESENT RESULTS

0 0,05 0.10 0.15 0.20

FI6. 9 MEASURED SUP RATIOS AND VOID FRACTIONS.

0.25 0.30STEAM QUALITY, x

0.35

10

8

6CO

I'Q.

8* 2

39.21 ±0.15 bar

= 89.9±0.9 WJcm2

-O- -o—»o-

0.10 0.15 0.20 0.25 0.30 0.35 x

LEGEND

LEVY {REED

BANKOFF (REF. 2)

PRESENT RESULTS

0.05 0.10 0.15 0.20 0.25 0.30STEAM QUALITY, x

0.35

FI6.10. MEASURED SLIP RATIOS AND VOID FRACTIONS.

10

cT 6

Q. i.-i

in

2

t 0.3 bar

a

0.05 0.10 0.15 0.20 0.25 0.30 0.35 x

1.0 T

,0.8

a q/A =91.6 ± 1.5 wjcm2

o qJA = 1240 t 1.0 w|cm2

2O

o 0.6eta.9 0.4o

0.2

-

. /

/ /

i

/

\L

LEGEND

LEVY (REF.1)

BANKOFF (REF. 2)

- PRESENT RESULTS

0.05 0.T0 0.15 0.20

FIG. 11. MEASURED SUP RATIOS AND VOID FRACTIONS

0.25 0.30STEAM QUALITY, x

035

CO

o

10

8 ~ 59.17 i 0.4 bar

"V

0.05 0.10 0.15 0.20 0.25 0.30 035 x

1.0

a q|A = 93.8 ± 0.5 wjcm2

O q|A=1209 t 1 4 w|cm2

J).8zo§0.6on

o

0.2*"

LEGEND

- - - LEVY (RSF. 1)

— BANKCFF (RRc F 2 }

- PRESENT

0.03 0 «l A 0.1! 0.20 0,25

?!G.12. MEASURED SLIP «<A1 ̂OS Å^D VOSO FRACTIONS

0 30 035STEAM QUALiTV, x

<

az<tuI-

INCEPTION OFBOILING

TRUE STEAM QUALITY

/ \COMPUTED STEAM QUALITY

POSITION ALONG TEST SECTION

FIG.13. SCHEMATIC STEAM QUALITY DISTRIBUTION ALONG TEST SECTION

39.21 bar

0.20 0.25 030 0.35 x

ö 0.8-zo

<u.

0.6-

o

02-

0.05 0.10 0.15 0.20

p= 29.49 barP p=9J5 bar

t

^ p=19,60 bar

6.93 bar_— -

«———-—

— ^

1

" p^Iw7\ p = 59.17 bar

~——f- """bar/

• Ä -

" Vf^\p=39.21

1

— i • —

bar

0.25 0.30STEAM QUALITY^

035

FIG.U. SUMMARY OF RESULTS

LEGEND

x s 0.20x - 0.10x ~ 0.05

to

a._]en

00 10 20 30 50

PRESSURE, bar60

FIG. 15. EFFECT OF PRESSURE ON SLIP RATIO.

1 -

5).

52.

53.

54.

55.

56.

57.

58.

59.

60.

61.

62.

63.

64.

65.

66.

67.

68.

69.

70.

71.

72.

73.

74.

75.

76.

77.

78.

79.

80.

81.

82.

83.

84.

85.

86.

LIST OF PUBLISHED AE-REPORTS

•50. (See the back cover earlier reports.)

Activation analysis of aluminium. By D. Brune. 1961. 8 p. Sw. cr. 6:—.

Thermo-technical dala for D2O. By E. Axblom. 1961. 14 p. Sw .cr. 6:—.

Neutron damage in steels containing small amounts of boron. By H. P.Myers. 1961. 23 p. Sw. cr. 6:—.

A chemical eight group separation method for routine use in gammaspectrometric analysis. I. Ion exchange experiments. By K. Samsahl.1961. 13 p. Sw. cr. 6:—.

The Swedish zero power reactor R0. By Olof Landergård, Kaj Cavallinand Georg Jonsson. 1961. 31 p. Sw. cr. 6:—.

A chemical eight group separation method for routine use in gammaspectrometric analysis. I I . Detailed analytical schema. By K. Samsahl.18 p. 1961. Sw. cr. 6:—.

Heterogeneous two-group diffusion theory for a finite cylindrical reactor.By Alf Jonsson and Göran Näslund. 1961. 20 p. Sw. cr. 6:—.

Q-values for (n, p) and (n, a) reactions. By J. Konijn. 1961. 29 p. Sw. cr.6:—.

Studies cf the effective total and resonance absorption cross section forzircaloy 2 and zirconium. By E. Hellstrand, G. Lindahl and G. Lundgren.1961. 26 p. Sw. cr. 6:—.Determination of elements in normal and leukemic human whole bloodby neutron activation analysis. By D, Brune, B. Frykberg, K. Samsahl andP. O. Wester. 1961. 16 p. Sw. cr. 6:—.

Comparative and absolute measurements of 11 inorganic constituents of38 human tooth samples with gamma-ray spectrometry. By K. Samsahland R. Söremark. 19 p. 1961. Sw. cr. 6:—.

A Monte Carlo sampling technique for multi-phonon processes. By ThureHögberg. 10 p. 1961. Sw. cr. 6:—.

Numerical integration of the transport equation for infinite homogeneousmedia. By Rune Håkansson. 1962. 15 p. Sw. cr. 6:—.

Modified Sucksmith balances for ferromagnetic and paramagnetic mea-surements. By N. Lundquist and H. P. Myers. 1962. 9 p. Sw. cr. 6:—.

Irradiation effects in strain aged pressure vessel steel. By M. Grounesand H. P. Myers. 1962. 8 p. Sw. cr. 6:—.

Critical and exponential experiments on 19-rod clusters (R3-fuel) in heavywater. By R. Persson, C-E. Wikdahl and Z. Zadworski. 1962. 34 p. Sw. cr.6:—.

On the calibration and accuracy of the Guinier camera for the deter-mination of interplanar spacings. By M. Möller. 1962. 21 p. Sw. cr, 6:—.

Quantitative determination of pole figures with a texture goniometer bythe reflection method. By M. Möller. 1962. 16 p. Sw. cr. 6:—.

An experimental study of pressure gradients for f low of boil ing water ina vertical round duct. Part 1. By K. M. Becker, G. Hernborg and M. Bode.1962. 46 p. Sw. cr. 6:—.An experimental study of pressure gradients for flow of boil ing water ina vertical round duct. Part I I . By K. M. Becker, G. Hernborg a n d M . Bode.1962. 32 p. Sw. cr. 6:—.

The space-, time- and energy-di'tribution of neutrons from a pulsedplan» source. By A. Claesson. 1962. 16 p. Sw. cr. 6:—.

One-group perturbation theory applied to substitution measurements withvoid. By R. Persson. 1962. 21 p. Sw. cr. 6:—.

Conversion factors. By A. Ambern!son and S-E. Larsson. 1962. 15 p. Sw.cr. 10:—.

Burnout conditions for flow of boil inq water in vertical rod clusters.By Kurt M. Becker. 1962. U p. Sw. cr. '6:—.

Two-group current-equivalent parameters for control rod cells. Autocodeprogramme CRCC. By O. Norinder and K. Nyman. 1962. 18 p. Sw. cr.6:—.

On the electronic structure of MnB. By N. Lundquist. 1962. 16 p. Sw. cr6 1 - — ~ .

The resonance absorption of uranium metal and oxide. By E. Hellstrandand G. Lundgren. 1962. 17 p. Sw. cr. 6:—.

Half-life measurements of 'He, »N, " O , »F, »Al, "Se"> and "°Ag. By JKonijn and S. Malmskog. 1962. 34 p. Sw. cr. 6:—.

Progress report for period ending December 1961. Department for ReactoiPhysics. 1962. 53 p. Sw. cr. 6:—.

Investigation of the 800 keV peak in the gamma spectrum of SwedishLaplanders. By I. D. Andersson, I. Nilsson and K. Eckerstig. 1962. 8 DSw. cr. 6:—.

The resonance 'integral of niobium. By E. Hellstrand and G. Lundaren1962. 14 p. Sw. cr. 6:—.

Some chemical group separations of radioactive trace elements. By <Samsahl. 1962. 18 p. Sw. cr. 6:—. '

Void measurement by the (v, n) reactions. By S. Z. Rouhani. 1962. 17. p.Sw. cr. 6:—. '

Investigation of the pulse height distribution of boron trifluoride pro-portional counters. By I. ö . Andersson and S. Malmskog. 1962 16 DSw. cr. 6;—.

An experimental study of pressure gradients for flow of boiling water

Boder'l962 Is ! " " 1 S w ^ ' 'o"— 3 ) - BY K ' M " B e c k e r ' G - He rnL"> ra and M.

An experimental study of pressure gradients for f low of boil ing waterin vert iral round ducts. (Part 4). By K. M. Beder , G. Hernborg and M.Bode. 1962. 19 p. Sw. cr. 6:—.

Measurements of burnout conditions for f low of boil ing water in verticalround ducts. By K. M. Becker. 1962. 38 p. Sw. cr. 6:—.

Cross sections for neutron inelastic scattering and (n, 2n) processes. ByM. Leimdörfer, E. Bock and L. Arkeryd. 1962. 225 p. Sw. cr. 10:—.

On the solution of the neutron transport equation. By S. Depken. 1962.43 p. Sw. cr. 6:—.

Swedish studies on irradiation effects in structural materials. By M.Grounes and H. P. Myers. 1962. 11 p. Sw. cr. 6:—.

The energy variation of the sensitivity of a polyethylene moderated BFjproportional counter. By R. Fräki, M. Leimdörfer and S. Malmskog. 1962.12 p. Sw. cr. 6:—.

The backscattering of gamma radiation from plane concrete walls. ByM. Leimdörfer. 1962. 20 p. Sw. cr. 6:—.

The backscattering of gamma radiation from spherical concrete walls. ByM. Leimdörfer. 1962. 16 p. Sw. cr. 6:—.

Multiple scattering of gamma radiation in a spherical concrete wallroom. By M. Leimdörfer. 1962. 18 p. Sw. cr. 6:—.

The paramagnetism of Mn dissolved in a °nc< B brasses. By H. P. Myersand R. Westin. 1962. 13 p. Sw. cr. 6:—. v

Isomorphic substitutions of calcium by strontium in calcium hydroxy-apatite. By H. Christensen. 1962. 9 p. Sw. cr. 6:—.

A fast time-to-pulse height converter. By O. Aspelund. 1962. 21 p. Sw. cr.6:—.Neutron streaming in D2O pipes. By J. Braun and K. Randen. 1962.41 p. Sw. cr. 6:—.

The effective resonance integral of thorium oxide rods. By J. Weitman.1962. 41 p. Sw. cr. 6:—.Measurements of burnout conditions for f low of boil ing water in verticalannuli. By K. M. Becker and G. Hernborg. 1962. 41 p. Sw. cr. 6:—.

Solid angle computations for a circular radiator and a circular detector.By J. Konijn and B. Tollander. 1963. 6 p. Sw. cr. 8:—.

A selective neutron detector in the keV region utilizing the "F(n, y)afreaction. By J. Konijn. 1963. 21 p. Sw. cr. 8:—.

Anion-exchange studies of radioactive trace elements in sulphuric acidsolutions. By K. Samsahl. 1963. 12 p. Sw. cr. 8:—.

Problems in pressure vessel design and manufacture. By O. Hellströmand R. Nilson. 1963. 44 p. Sw. cr. 8:—.

Flame photometric determination of lithium contents down to 10-3 ppmin water samples. By G. Jönsson. 1963. 9 p. Sw. cr. 8:—.

Measurements of void fractions for f low of boi l ing heavy water in avertical round duct. By. S. Z. Rouhani and K. M. Becker. 1963. 2nd rev.ed. 32 p. Sw. cr. 8:—.

Measurements of convective heat transfer from a horizontal cylinderrotating in a pool of water. K. M. Becker. 1963. 20 p. Sw. cr. 8:—.

Two-group analysis of xenon stability in slab geometry by modal expan-sion. O. Norinder. 1963. 50 p. Sw. cr. 8:—.

The properties of CaSOa:Mn lhermoluminescence dosimeters. B. Biärn-gard. 1963. 27 p. Sw. cr. 8:—.

Semianalytical and seminumerical calculations of optimum materialdistributions. By C. I. G. Andersson. 1963 26 p. Sw. cr. 8;—.

The paramagnetism of small amounts of Mn dissolved in Cu-AI andCu-Ge alloys. By H. P. Myers and R. Westin. 1963. 7 p. Sw. cr. 8:—.

Determination of the absolute disintegration rate of Csr7-sources by thetracer method. S. Hellström and D. Brune. 1963. 17 p. Sw. cr. 8:—.

An analysis of burnout conditions for flow of boil ing water in verticalround ducts. By K. M. Becker and P. Persson. 1963. 28 p. Sw. cr. 8:—.

Measurements of burnout conditions for f low of boil ing water in verticalround ducts (Part 2). By K. M. Becker, et a l . 1963. 29 p. Sw. cr. 8:—.

Cross section measurements of the s8Ni(n, p)s3Co and "Si(n, a ] "Mg reac-tions in the energy range 2.2 to 3.8 MeV. By J. Konijn and A. Lauber.1963. 30 p. Sw. cr. 8:—.Calculations of total and differential solid angles for a proton recoilsolid state detecor. By J. Konijn, A. Lauber and B. Tollander. 1963. 31 p.Sw. cr. 8:—.

Neutron cross sections for aluminium. By L. Forsberg. 1963. 32 p.Sw. cr. 8:—.

Measurements of small exposures of gamma radiation with CaSO4:Mnradiothermoluminescence. By B. Bjärngard. 1963. 18 p. Sw. cr. 8:—.

Measurement of gamma radioactivity in a group of control subjects fromthe Stockholm area during 1959—1963. By I O Andersson, I Nilsson andEckerstig. 1963. 19 p. Sw. cr. 8:—.

The thermox process. By O. Tiälldin. 1563. Sw. cr. 8:—.

The transistor as low level switch. By A. Lydén. 1963. Sw. cr. 8:—.

The planning of a small pilot plant for development work on aqueousreprocessing of nuclear fuels. By T. U. Sjöborg, E. Haeffner and Hultgren.1963. Sw. cr. 8:—.

Förteckning över publicerade AES-rapporter

1. Analys medelst gamma-speklrometri. Av D. Brune. 1961. 10 s. Kr 6:—.

2. Bestrålningsförändringar och neutronatmosfär i reaktortrycktankar —några synpunkter. Av M. Grounes. 1962. 33 s. Kr 6:—.

3. Studium av sträckgränsen i mjukt stål. G . Ostberg, R. Attermo. 1963.

Additional copies available at the l ibrary of AB Atomenergi, Studsvik, Nykö-ping, Sweden. Transport microcards of the reports are obtainable throughthe International Documentation Center, Tumba, Sweden.

87.

88.

89.

90.

91.

92.

93.

94.

95.

96.

97.

98.

99.

100.

101.

102.

103.

104.

105.

106.

107.

1C8.

109.

110.

111.

112.

113.

114.

115.

116.

117.

118.

119.

120.

121.

122.

EOS-tryckerierna, Stockholm 1963