A translation from

Atomit: Energy of Canada

by

C. PETERSEN

Kernforschungszentrum

translated by

R. Gerarts and L.G. Bell

translated from

Gesellschaft fur Kernforschung m.b.H., Karlsruhe,

report KFK-Ext. 6/73-6, March 1973

Power Projects

Sheridan Park Research Conrtinunity

Mississauga, Ontario

March 1975 ASCL-5101

LITEPATURE SEARCH ON SOME PROPERTIES OFZIRCA1OY-4 AT HIGH TEMPERATURES*

by

C. PetersenKernf orschungszentruni

(Nuclear Research Centra)Karlsruhe, Germany

Translation by R. Gerarts and L.G. Bell

Power ProjectsSheiidan Park Research Community

Mississauga, OntarioMarch, 1975

^Translated from the Germair for Atomic Energy of AECL-5101CariaM%imite"a from Gesellschaft fur Kertiforschangisvb.H., Karlsruhe^ report KFK-̂ Ext. 6/73-6, March, 1973

Données g l a n é e s dans l e s p u b l i c a t i o n s c o n c e r n a n t

c e r t a i n e s p r o p r i é t é s du Z i r c a l o y - 4 aux h a u t e s t e m p é r a t u r e s *

par

C. P e t e r s e n

Kern fo r schungszen t rum( C e n t r e d ' é t u d e s n u c l é a i r e s )

K a r l s r u h e , Allemagne

* Ce r a p p o r t o r i g i n e l l e m e n t p u b l i é dans G e s e l l s c h a f t fu rKernforschung m . b . H . , Karl s h r u h e (Rappor t KFK-Ext.6 / 7 3 - 6 , Mars 1973) a é t é t r a d u i t d ' a l l e m a n d en a n g l a i spour l ' E n e r g i e Atomique du Canada , L i m i t é e p a rR. G e r a r t s e t L.G. S e l l .

Résumé

Ces données glanées dans les publications con-cernent quelques propriétés mécaniques et physiques duZircaloy-4 pour la gamine de températures allant de 600°C"a 1800°C. On décrit le comportement des efforts-contrain-tes de la résistance ultime et de 1s ductilité dans lasconditions de pression interne, d1expansion thermique, deconductivité thermique et d'émissivite totale.

L'Energie Atomique du Canada, LimitéeGroupe électronuelêaire

Sheridan Park Research CommunityMississauga, Ontario

Mars 1975

AEÇ.U5T&Ï.

LITERATURE SEARCH ON SOME PROPERTIES OFZIRCALOY-4 AT HIGH TEMPERATURES*

by

C. PetersenKernforschungs zen trum

(Nuclear Research Centre)Karlsruhe, Germany

Translation by R. Gerarts and L.G. Bell

ABSTRACT

In this literature search some mechanical andphysical properties of Zircaloy-4 are compiledfor the temperature interval of 600 to 1800°C.The behaviour of stress-strain, ultimate strength,and ductility under internal pressure, thermalexpansion, thermal conductivity, and totalemissivity are described.

Po^sr ProjectsSheridan Park Research Coiamunity

Mississauga, OntarioMarch, 1975

^Translated from thE German for Atomic Energy of AECL-5101Canada Limited from Gesellschaft filr Kernforschungni.b.E. „ Karlsruhe, report KFK-̂ Bst; 6/7S-6, March. 1973.

TABLE CF CONTENTS

1 . Introduction

2. Stress vs Strain Properties of Zircaloy-4 and Zr-0.7 5n

3. Ultimate Stress Behavior of Zircaloy-4

4. Expansion Behavior of Zircaloy-4

5. Thermal Expansion of Zircaloy-4

6. Thermal Conductivity of Zircaloy-4

7. Emissivity of Zircaloy-4

8. Summary

Bibliography

Tables

Fig. 1 - 2 2

— 1 ~

1. Introduction

The loss of coolant arc w!r-nt (LOCA) i :; vuris ir]f-rr-<i f; y-jf- the- mcst scnfjus

failure in the operation of light water reactors. This accident is caused

by a rupture in the piping system of the primary coolant circuit and results

in a rapid loss and pressure drop of the coolant followed by a rapid tem-

perature rise of the fuel element sheath. D'.ring the heat-up period of

the sheath, ballooning and isolated bursts may occur due to the inner proa-

sure of the fission i;as.

Zircaloy-4 is used as a sheath maceriaJ in light water reactors; it melts at

about 1871 C. During heat-up it passes an allotropic transformation from the

denser hexagon structure (a) to the cubic epicentric structure (B). This

transformation starts at about 815"C and ends at about 9fc>5 C. fig. 1 shows

the temperature range for the analysis of the loss of coolant accident in

connection with the stress-strain properties of the sheath. The lower limit

of the test temperature range for the analysis of the loss of coolant accident

is given by the normal operating temperature of tne sheath (approx. 320 C).

The actual critical test analysis range for the loss of coolant accidento o

between 600 C and 1200 C was supplied by General Electric, Combustion En-

gineering, Westinghouse, Babcock and VJilcox and ORNL, using internal pres-

sures* between 0.035 and 1.41 kp/min . The sheath may be damaged in this

temperature range.

2. Stress vs Strain Properties of Zirculoy-4 and Zr-0.7 r-

oTensile strength data are available for Zircaloy-4 up to 500 C; this may

be the upper limit of the operating temperatures of boiling and pressurized

water reactors. Few data are available for higher temperatures.

Data from tensile tests performed by J.F. White on Zircaloy-4 plate-*1

at a crosshead speed of 0.05 min in a helium atmosphere, have been

incorporated in fig. 2 for temperatures of 650, 900, 1200 and 1500 C.

* Editor's note: kp = kilopond = kilocrram force,i.e., 9.B06 65 N.

" 2 —

This clearly shows that there is no longer ary hardening at temperatures

of 650 and 900°C for strains V" beyond 0.5. At temperatures of 1200 and0

ISOC^C it can even be assumed that the yield stress will just about equal

the ultimate stress.

M..1. Luton iind J.J. Jonas' performed covnpx'ess"" on tests on various

zirconium-tin alloys at high temperatures. The aJ loy with a 0.7'!, Sn

content has the closest resemblance to Zircaloy-4 even though the tin

jontenr is half of what it is in Sircaloy-4. The tests were done at 775 C- 4 - 1 -.1

at a ief orinat ion rate between 10 s and 1 s in an argon atmosphere.

ffiq. 3). At the test temperature of 775 C, lower stress values are obtained

as the deformation rate is reduced. At the hi<jh deformation rate of 1 s """,

the stres-i incivcsss until the strain reaches 0.4. At a deformation rate

of 10 s , the stress only incrtrases up to a strain of 0.04. The stress/

strain graphs also show that at larger expansions there is no more hardening.

3. Ultimate Stress Behavior of Zircaloy-4

Th? ultimate strength values 0B depend mainly on the degree of cold work

which is still latent in the material at the individual test temperature.4) •>

Tests performed by Woods indicated a strength of 78.7 kp/mm ; the tensile

tests were carried out at room temperature on 78% cold formed Zircaloy-4O 2

sheaths *rhich had been annealed at 510 C, Compared with 57 kp/mm for 78%

cold formed material annealed at 650 C, a difference of about 40% in strength

is obtained. Apart from this, the tensile strength of material annealed ato !'

510 C is already 50% lower than the cold formed material. At temperatures

above 600 C the effects of cold forming disappear rapidly,- the difference in

strength between the cold formed material and material which was annealed

after cold forming is wiped out. Fig. 4 shows the ultimate strength at

temperatures of up to 1800°C (i.e. about 70°C below the melting point) of

annealed Zircaloy-4 plate specimens with load applied in the direction

of rolling. Tests at higher temperatures were performed at a strain rate

of 0.06 min . Scott's values for the cold formed tube samples corres-

pond favorably with annealed plate samples.

Fig. 5 snows a comparison of ultimate stress tests a which were made

using transient temperature tests ' with a heat-up rate of 25 C/s and

3 other tests " oi" boiling-water, reactor sheaths, Although the graph?

follow a similar pattern, the ultimate strength values measured by

Hardy are at higher temperatures than the other tests. 7/his is partly9)

due to different test conditions. Tests performed by Emmerich et al,

'were terminated when the expansion reached 34% as at a greater expansion it

is no longer possible to assure an unhindered coolant flow in case of

emergency cooling. Therefore, the valuer measured by Emmerich et al. at

a heat~up rate of 22°C/s are not necessarily always ultimate stresses.

Moreoverf these tests were performed in a steam atmosphere as were those

carried cut by Hobson and Rittenhouse and th.is reduces the expansion

because the Zircaioy oxidizes especially at high temperature?.

Waddell and Rittenhouse made use of the rupture strength by first

heating up to the desired temperature and than subjecting the tubular2

specimen to a pressure of 0.035 kp/ram . The lower expansion velocity

obtained in this manner may cause creep at the set high temperature. Failure

could therefore occur at lower temperatures. Test results t. -tained by Hobson

et al. correspond most closely to those obtained by Hardy ' , These tests

were performed in an inert cover gas citmosphere with a heat-up rate of

28 C/s and with expansion unhindered in both the axial and radial direction.

Nevertheless.- the tensile stresses are xower than those measured by Hardy.

This may be due to a more uniform wall thickness of the sheath? tested oy

Hardy as compared with the boiling water reactor sheaths tested by Hobson

Hobson noticed that variations in the wall thickness have a considerable

bearing oil the ultimate strength. Moreover, the ultimate strength values

given by Silpbsdn very clearly show a drop within the a-B phase transformation

range. ,'Hobson suspects that tho a-3 transformation, being a shear action,

adds to the force eserted on the specimen wall and causes an earlier rupture.

Eme*y c?t .al.10) checked the strength of Sircaloy-4 sheaths with internal

pressure tests at pressures of 0.14-1.76 kp/irat̂ and hat-up rates of

1 •;. ~> - 96.2 C'/s in a helium atmosphere. As can be seen from fig.6 the

rupturt temperature T aoes not depend on the inner pressure to a great

extent. The differences ir. failure temperatures for all pressures are

tairly small, being o. ly about 194°C max. The same figure shows the

ultimate strenqth values for 'Zircaloy-4 sheaths which were distorter! in

an axial direction. Compared with the values for transient temperatures,

there is no big difference.

ilibsoi! and Ri tti-r.hrnse " made similar test's at higher temperatures. They

checked for failure v.ith internal pres.- r s as a function of temperature

under transient test conditions (pressures of 0.035-0.703 kp/mm2 and heat

up rates of 5.5-55.5 C/i). Fiq.'1 gives the maximum pressure P _ v.-.

temperature, using the heat-up rate as a parameter. This shows that in

the two-phase ar-̂ a (a+6) at pressures between 0.14 and 0.42 kp/mm'' a burst

occurs at low circumferential expansion.

Osborne and Parker carried out burst tests on individual tubes of

irradiated Zircaloy-4. The tast conditions were similar to those of Hob-12)

son except that measurements ware made in a closed environment of a

steam-argon atmosphere. The maximum expansion recorded for irradiated

material was 50% whereas the majority of values were in th<= 50-40% range.

Short-duration tests were made at General Electric on Zircaloy-4 plate

specimens at high temperatjres (up to 1800 C ) . The tests were made in

an argon atmosphere with a constant distortion velocity of 0.13 cm/min

in order to obtain data on ultimate strength. Supplemertary tests were

made in a helium atmosphere at temperatures in the range of 650-r.500°C,

using the same Zircaloy-4 plate specimen (0.76 mm thick) in order to

obtain the yiald stress values of the material. The distortion velocity

was measured with an electrical optical extensometer. The results are

shown in fig.8. This graph shows that in the temperature range of 6r-0 -o -i

900 C at a distortion velocity of 0.005 min the ultimate stress is lower

for each temperature than in the report mentioned above. This means that

the strength depends on the distortion velocity. In order to check this

more accurately, additional measurements were taken with distortion velo-

cities of 0.05 and 0.1 min . These results are also shown in fig.8 and

seem to confirm the relation between the strength and the distortion

velocity.

White" tested zii'caloy-4 tubes with irit_rnal pressure under steam and

an inert atmosphere. These tests toe were halted when the expansion

reached 34%, because at: a greater expansion Lt is no lonqer possible to

ensure an unhindered coolant flow m case of emergency coolino. Fig.9

shews ditferent heat-up rates vs strep U ff, caused by internal pres-

sure in the tube wall. Moreover, i* . >ws the point where ductility

changes to brittleness in a steam at' sphere. The results of this check

show the general behavior of Zircaloy-4 tubes under an internal pressure

with a steam atmosphere present dating heating.

Following is a summary of the test results:

1) The material fails by rupture at less than 34% circumferential ex-

panr.ion with internal pressures under 0.05 kp/nun (= 0,35 kp/mm effective

stress) with heat-up rates of less than 50 C/s. At higher heat-up

rates, an uneven behavior is noted; it includes so:tie sheaths which,

even at temperatures of up to 1700 (

failure at low to medium expansion.

even at temperatures of up to 1700 C, did not show any material

2) Sheaths subjected to an internal pressure of 0.06 kp/mm2 (= 0.43 kp/mm

effective stress) fail by rupture at a circumferential expansion of less

than 24?o at heat-up rates of over 200 C/s.

3) Sheaths which are subjected to internal pressures between 0.07 and 0.C8

kp/mm (=0.51 - 0.58 kp/mm'' effective stress)fail either because of a ducx.il

brittle rupture. The basic rupture behavior in this pressure range

cannot be defined easily, because the rupture mechanism is very sen-

sitive to slight variations in correlated reactions such as the mechanic-

al properties of the sheath, the internal pressure, temperature and

degree of oxidation.

- 6

4) At internal pressures above 0.08 kp/tran2 (= 0.58 kp/ram2 effective stress) and

heat-up rates of a few tenths of a degree Celsius per second, a ductile

rapture occurs similar to i.he one which was observed during annealing

9)tests" in an argon atmosphere.

Emery et al.10' checked the effect of the hea'-. up rate (12.7 - 96.2°C/s)

on the rupture for temperatures up to 750 C and at an internal pressure

of 1.76 kp/r.r: . As can V een from fig. 10, it is hardly possible to

observe a dependence of the rupture temperature on the heat-up rate in this

temperature range. However, at temperatures higher than those used during

tests performed by Hobson and Rittenhouse , an increase in the rupture

temperature occurs at an internal pressure of 0,07 kp/mm2 and heat-up rates

of 5.5 - 55.5 C/s. This effect was not noted in the a-phase nor in the

2-phase area (a+fi) . However, iiobson and Rittenhouse suspect that the

shear action during the transformation through the 2-phase area (a+3) is

the reason for the dependence on the heat-up rate. According x> Hobson,

the heat-up rate of the test sample could be lowered since t..e phase trans-

formation is endothermic.

4. Expansion Behavior of Zircaloy-4

12)Hobson and Rittenhouse investigated the circumferential expansion which

occurs at higher temperatures under transient test conditions when the

sheath ruptures (pressures between 0.035 and 0.703 kp/mm2 and heat-up

rates of 5.5 - 55.5 C/s). Fig.11 shows the circumferential expansion E

vs max. pressure P . From this can be seen that in the 2-phase area

(a+3) at pressures between 0.14 and 0.42 kp/mm2 the circumferential expan-

sions (20-40%) reach a minimum.

l graphs representing the expansion are difficult to compare be-

cause both material and test conditions were too varied.

In reference 5 , the elongation of tensile test specimens, measuring

25.4 x 6.3 x 0.76 mm (length x width x thickness) is shown as a function

of temperature (fig.12) . Below 400°C, the elongation of the specimen in

general does not depend on the ttmperature. Thereafter the elongation

increases and reaches a maximum of about 85% at 1200 C. In comparing with4)

burst tests performed on tube samples with 78% cold work , a difference

is found in the temperature range of 360-550 C; in this latter case, the

elongation increases to only about 25%.

In another test , the elongation £ of Zircaloy-4 plate samples was also

represented as a function of temperature where the distortion velocity e

was varied (fig.13). Except foi: the test performed at 900°C, the curve

follows the same trend. Maximum ductility is reached around 1200 C. The

values do net indicate a dependence of the specimen elongation or. the

distortion velocity.

Hardy investigated the behavior of Sircaloy-4 sheaths at high tempera-

tures and made internal pressure tests from 0.035 to 1.41 kp/mm2 at a

heat-up rate of 25 C/s. After a certain temperature was reached, it

was maintained until rupture. Fig.14 shows that at an increasing temper-

ature and an internal pressure of 0.07 kp/mm2 the tube initially shows

little circumferential expansion. The maximum circumferential expansion

from 815 to 940°C, i.e. a rise of 125°C, is only 0.1 to 1%. At a con-

tinuing temperature rise the circumferential expansion also increases from

1% to 10%. The semi-logarithmic representation shows a further circum-

ferential expansion from 10 to 11C% up to rupture for the next 10 C.

-i \

In tests performed by Waddell and Bittenhouse^ , 5 distinct temperatures

were selected: 590, 790, 890, 980 and 1150 C where:

590 C is in the range of phase af

790°C is just below the phase transformation a-*-(ct+3),

89Q°C is in the middle of-the (a+B5 phase,

980°C is just above the phase transformation (a+3)-»-$,

1150 C is in the range of phase (3.

The internal pressure tests were made isotherrnally at the temperatures

mentioned above at different pressure gradients from 0.035 to 0.039

kp/mm2...Pig.15.shows the circumferential expansion E V S temperature.

The lowest circumferential expansion (50 - 70%) was measured at 1150 C,

the highest (50 to >1403,} at 790°C. It should be noted that the size

- 3 -

of the rupture cannot be determined from the circumferential expansion.

Besides, the circumferential expansion also depends on the variations8)

in the wall thickness. Hobson et al. checked this out in transient

burst tests and found differences in expansion up to a factor of 2.

There follows a summary of the rupture behavior of Zircaloy-4 in relation

to time.

Fia.16 shows the ultimate stress graphs as a function of time for the

temperature range 600-1000°C according to research done by Hardy .

The test specimenswere heated up at a rate of 100 C/s, i.e. the period

shown on the graph is the holding time before rupture ar the temperature

reached. Ultimate stress graphs are usually straight lines, but curves

for lower temperatures (650-800°C) show a deviation from the straight line

for brief periods. It could not be ascertained why this effect was

limited to the a phase.

Baker14) also measured similar graphs, except that in this case the internal

pressure .P. is shown in relation to the period before rupture for the

temperature range of 850-1100°C (fig.17) .

5. Thermal Expansion of Zircaloy-4

Scott measured the thermal expansion of Zircaloy-4 by means of an electro-

mechanical dilatometer. This instrument records the expansion of the test

sample in accordance with its temperature. Because of the strong anisotro-

py of Zircaloy-4, different graphs are obtained for the thermal expansion

coefficient a in a radial and axial direction of the specimen as a function

of the temperature. These are shown in fig. 18 and 19. A fltop in the

thermal expansion coefficient occurs in the (a+B) phase in the radial (sic)

direction.

6. Thermal Conductivity of zircaloy-4 : : •

It is not unusual to have differences of one or two decades of thermal con-

ductivity values for one and the same material. Some of these are due to

the difficulty of measuring the thermal conductivity. However, considerable

- 9 -

changes in thermal conductivity oncur in some materials when there is a

minor deviation in the chemical composition and microstructure. A single

affect may depend on the temperature, i.e. there may be a wide deviation

at low temperatures which may disappear again at high temperatures. Dur-

ing a loss of coolant accident, tho thermal conductivity of the composi-

tion may be affected to a large extent by the presence and structure of

metallic and oxide phases in the sheath material.

Faith measured the thermal conductivity X of Zircaloy-4 in the

temperature range 400-1500°C, Scott in. the range 80-700°C

and Chirigcj et al. in the range 100-350°C. All these values are

shown in fig. 20. Scott values were obtained from tests on

tube specimens; the deviation from the calculated curve of the smallest

error squared amounted tc ±10%. Feith's average values are within ±5%

of those on the curve; furthermore, these values show an increase for

temperatures over 1000 C. Values measured by Chirigos fcr Zircaloy-4

up to 600 C correspond to those obtained by Feith; over 600°C, a con-

siderable increase in the thermal conductivity is noted. The deviation

from the Feith values reaches about 13% at 850°C.

Feith values are appropriate for calculating coolant losses. However,

errors due to the high oxygen content in the metal and external oxide

layers, must be taken into account as was noted in the above

description of the factors which affect the thermal conductivity; these

conditions manifest themselves when a loss of coolant occurs.

an example shows that this consideration is important. Following is the

effect of a layer of oxide on a Zircaloy-4 sheath at 1200 C: Assuming

that the sheath has a wall thickness of 0.51 mm and that a 0.051 mm

thick layer cf oxide ZrO, has built up with a thermal conductivity of

0.0'25 ft/cm C, further, that the combined thermal conductivity of the• - . • . - . . . • - • - . - . .. • ,- .. - ,.. . •• o

oxygen richmaterial and the Sircaloy-4 together amount to 0.3.1 W/cm C,

the results then show a oropof the thermal conductivity in a radial

direction (wall thickness) from 0,31W/cm°C to 0.147 W/cm°G (a decrease of

approK. 50%) and to 0.28 W/cm°C in an axial direction fa decrease ofapprox. 10%) . The presence of a layer of oxide in a radial direction

- 10 -

has a greater effect on the thermal conductivity than a possible error

in the measurement of the values of thermal conductivity of Zircaloy-4.

7. Emissivity of Zircaloy-4

Fig.21 shows the total emission e~ of Zircaloy-4 in relation to temperature

and for different typos of oxidation. According to White , the specimen

material was oxidized in a steam or oxygen-argon atmosphere. Subsequently,

the emission was measured in a vacuum. The thickness of the oxide layer

varied from 5 to 200 \m. The radiation behavior C™ of the oxidized spe-

cimens follows a parabolic pattern. The specimens which are saturated

with oxygen as well as the non-oxidized sample are shown for comparison.

Isothermal tests were also performed on the Zircaloy-4 in a steam atmosphere

in order to check the change in emissivity when the layer of oxide increases

with relation to time. The results are shown in fig.22.

The general trend shows that the values for the total emission of non-

oxidised material almost immediately increase from 0.2 to 0.7 and thereafter

very slowly increase to 0.8. After a prolonged period - dependent on the

test temperature - the emissivity again decreases. This was to be expected

since, according to Cox , the total emission of ZrC, in the corresponding

temperature range lies between 0.3 and 0.4,because the thicker the oxide

coat which forms on the surface, the sooner the emissivity of pure ZrO

is reached. However, since the times and temperatures assumed at a loss

of coolant accident are less, values of 0.7-0.8 should be considered for the

total emission.

8. Summary

The stress/strain behavior of Zircaloy-4 and Zr-0.7 Sn depends on the dis-

tortion velocity. No hardening occurs at high temperatures and low distor-

tion velocities. The ultimate stress behavior'of Zircaloy-4 is affected

by the a-3 phase transformation in both isothermal and transient tests.

It was found that rupture behavior also depended on the distortion velocity..

- 11

The expansion behavior for high temperatures and high internal pressures -

even under a steam atmosphere - if- still good. Only in the range of the

£-phase was it noted that expansion depends on heat-up rate. There is no

dependence on the distortion velocity.

Due to the strong anisotropy of "ircaloy-4, the thermal expansion co-

efficient shows different values in the radial and axial directions of

the sheath.

The thermal conductivity after oxidation rapidly decreases by about 50%

in the radial direction.

The emissivity of non-oxidized Zircaloy-4 is about 0.2-0.3, whereas values

of 0.7-0.8 were measured with an oxidized specimen.

It is often difficult to make an accurate comparison of the values given

in the publications mentioned because, unfortunately, they do not always

state the exact test conditions, how the specimens were treated or the

technological and metallurgical conditions of the material investigated.

12

P.ibliography

1) Waddeli, j r . , R.D. ..:,i.:l P.L. Rittenhouse:

"High-Temperature Burst Strength and Duc t i l i t y of Zircaloy Tubing"

Paper: 0RNL-TM-3?«c\ March 1971

2) White, J . F . :

"Physicochemical Stud ies of Clad UO? under Reactor Accident Conditions"

Paper: GEMP-1012 ( P t : 2 ) , P. 203-252

General Electr ic Co., Cincinnat i , Ohio, Nuclear Systeir, Program

3) Luton, M.J. and J.J.. Jonas:

"Solute Strengtheniric a t High Temperatures in Zirror.ium-Tin Alloys"

Canadian Metallurgical Quarterly, Vol. 11 , Mo. 1 (1972)

4) Woods, C.R.:

"Propert ies of Zircaloy-4 Tubing"

Paper: WARD-TM-5B5, Appendix C

5) Sixth Annual Report •;- High Temperature Materials Program, Part-A r

GE-13MPO

Paper: GEMP-475A, Me; rch 31 , 1967, P . 261-263

6) S c o t t , D.B.:

"Physical and Mecha-r.caJ Properties of Zircaloy-2 and 4"

Paper: WCAP-3269-41, May 1965

7) Hardy, D.G.:

"High Temperature Expansion and Rupture Behaviour of Zircaloy Tubing"

Fuel Engineering Branch Atomic Energy of Canada Limited, Chalk River,

Nuclear Laboratory Chalk River, Ontario, Canada, March 1973

8) Hobson, D.O.; M.F. Osborne and G.W. Parker:

"Comparison of Rupture Data from Irradiated Fuel Rods and Unirradiated

Cladding", Nuclear Technology, Vol. 11, Aug. 1971, P. 479

9) Emmerich, K.M.; E.F. Juenke and J.F. White:

"Failure of Pressurized zircaloy Tubes During Thermal Excursion in Steam

and Inert Atmospheres", ASTM--STP.458 American Society for Testing and

Materials, Philadelphia, Pennsylvania, 1969

13

10) Emery, A.D.; D.B. Scott and J.P, Stewart:

"Effect of Heating Rate and Pressure on Expansion of Zircaloy Tubing

During Sudden Heating Conditions"

Nuclear Technology, Vol. 11, Aug. 1971, P. 474-479

11) Hobson, D.O. and P.L. Rittenhouse:

"Embrittlement of Zircaloy-Clad Fuel Rods by Steam During LOCAL

Transients", Paper: ORNL.4758, Jan. 1972

12) Hobson, D.O. and P.L. Rittenhcuse:

"Deformation and Rupture Behaviour of Light Water Reactor Fuel Cladding"

Paper: ORNL-4727, UC-80-Reactor Technology, October 1971

13) Osborne, M.F. and G.W. Parker:

"The Effects of Irradiation on the Failure of Zircaloy-Clad-Fuel-Rods"

Paper: ORNL-TM-3626, Jan. 1972

14) Baker, J.N.:

"Fuel Element Integrity and Behaviour in a Loss of Coolant Accident"

Paper No. 14 of the CREST Specialist Meeting on Emergency Core Cooling

for Light Water Reactors, Munich, October 18-20, 1972

15) Feith:

"High Temperature Materials Program Progress Report No. 61"

GE-NMPO; Paper: GEMP-61, September 30, 1966

16) Chirigos, J.N.j s . Kass, W,W. Kirk, G.J. Sal', sggio:

"Development of Zircaloy-4 Fuel Element Fabrication - I . "

International Atomic Agency 1961f P. 45

17) Cox, R.L.:

"fimittance of Zirconia to 4600°F"

Boeing Report No. 3-100012R19, Catalogued by DDC as AD-434003, April 30,

1962

*̂ ^

Fig Author

2)

Relationship

3) c.

Temp.Range°

Heat-OpRate

650-1500

775

DistortionVelocity

0.05 min

TestSample

Plate

Kf4-1 s Plate Argon I leTestAllov

rupture, l. •.-.

hardening IJT. to be eK^i*dt hi ah temperatures

^o harden!nq occurs ar lewdistortion velocities

4) (!„, T RT Tube51C°C/

Air Up to 600"C affected bythe cold work snd heattreatment

5)

6)

1)

7)

» T

B'

0 ,TBO

RT-1800

RT-750

560-1150

0.06 !nin Plate Annealed inert ' Terusi le: Test

Plate

Tube

10%kv

750-1225 25 Tube

TensileTest

inert ; Internali Pressure

inert ', ]nt"rialP r*'c sure

CiMii :nat .-b i;i-i of theVdhn-: di'Sj.ite differentprior treatment

Creep action possible

Highest Ultimatestress values due tosiiqhr variations in vra1.1thickness

o2

fin <v

•w o u• i aE* < Dt

4 i-4 > i <fl •!->O H 0) Cwt id n a)a. c &•• e

4J Q,Hi 6O 3

a m> •o

1/1 XW 0i>

4> JQIA

•O

»J «

5 S3 3

at

u -f

XI

o t >g P*

u w. § fi

y w ©« uU O I'l

4 h

S 3ID

<u a

uu•

9»

n si

HI t)0i "rt Mi-S H 3+1 41 J3J in

s

Si

•§

! !

5> e

H V

H ft

igUl X

Is I

s tn

ISl-tCM

H UIB JJ HC O -W

•3»o d•p o

-H 01Q >

?

ino ino O •-»

J1in1

O 1

<TiI

O

o

r-t

iCO

83<

w i tin nj i

0 B K

Fig.

f

• • I . , i i

10..

\<S

\\

r J,

LZ

r

1-i

^13

^itythor

i

" 1 2 ) , 'r1

-U

>.

< 4f

, 2)

1

Relationship j

TBnich' - (Heat-Uj* 1rate1 ^

TBruchf• . J

Heat-OpRate L

flx' V-:

V T"

r

Temp. -Bange^£°C> "

(b40-7^!0

10'ao- i1200

v. ^

780- -1430

RT-550i

lRt-1700

600-1500

Heaf-U|>R^te<°c/*0

12,7-96,5

5r,5-!:5(5

b,5-55,5

I

-

DistortionVelocity

0,00b .0,05 }mm"0,1

TestSample

Tube

"JPabe

lube

ifabe

Plate

Plate

Prelimi-naryTreat-menr

Cold .Formed

Sam; leaindi rectiorofrolling

( -Testfitoos-phere

inert

inert

inert

inert

inert

inert

Notes

InternalPrass ire

Interna!Pressure

InternalPressure

InternalPressure

TensileStrength

TensileTest

Results

Failure temperatureTBruch a s C Q t a f f c c t e d

by heat~up rate

Since o+S cransfofmationis endothermic, lowering •of h»at-up iata ispossible

in 2-Pha«;e area (a+B)m m . expansion -at -P ^ 0.14 - 0.42 Jcp/BSR

Expansion between 3C0and 53O°C is lower thanm tensile cest.

Up to 300 C temperature doesnot affect expansion, max.expansion occurs -at 1200°c

Expansion is not affectedby distortion velocityMax. expansion at 1200°C

Figr.

14

15

16

17

]

t

!r

io,'.

author

7/

1)

7}

14)

6)

6)

ev

Relationship

VT

0 , TB Bruch

xr Bruch „

n, T"

A, T f

Temp.Range(°C)

830-1050

590-1150

650-1000

850-1100

RT-1000

St-600

80-780

Heat-UpBate("C/s)

100

100

•

DistortionVelocity

0,035-0,039kp/mm2

min

TestSample

Tube

Tube

Tube

Tube

Tube

Tube

Prelimi-naryTreat-ment

TestAtmos-phere

inert

inert

inert

inert

inert

Notes

InternalPressure

InternalPressure

InternalPressure

InternalPressure

RadialDirection

AxialPirecticii

Results

Rapid increase inexpansion in the range ofthe '.'.-Phase in thelogistic representation

Max. expansion at 80D°C;niin. expansion at 1150 C;it is not possible todefine the type of rupture

Deviation of the TensileStrength curve from astraight line in thea-region

Similar development as initem 5

In a radial direction dropin o+© area, in general:thermal expansion variesdue to stiongrayiisotrophyof Zircaloy-4

Correspond to values initeia 14

ii•RltS

i l lIPlip##»fli

ill

i l:«*ti'-*!-,

«f

mm§m

mmStSfipf

nn

lititiifmill

'mmmmmm::&latibnshipi

^ ^

IliiiiiSii

mmm

mpm

ffioblaid

Illmfcoimtfffaooj

;-;\'1V-:"-;'-"-::.\f,.Vt : - ? . • • . . • -_-•- . : ;"""•"

liiii;'.?-&sXjjr.~~.-z£t:. •••:••"

illiSSSS ;.- |v;;::V '̂VA-'' • -.ft.'.: . .

S f f i S :•••';;: r ri,?,i::.'\ '-;v .-.-.i! , ; ' « i ; . . ; • . ^ . • •;.,

.?|ii(otheaj

SlDil^rtioi^;Svel6ciiy;^;::

s i - . - ; ? J ? / i ^ ••.'•.•!"

• ; S ; _ . ' - ' V ' V ' i : " - . •• - • : ••

••Si':- Vv;?'-?"--'--:.'--'."--:;: i

^ : U - T v J ^ ' ; ..'• '•.-' •''

p . ' : ' ? ' ' ' ' - '•'•'-'• :'

|,^st&

• " • ' ; ' • ' v _ :1 . , ' ""-*;• . " •

'••'.'•".- '-' • - • ' . ' . • •

' • / • - . . • : ' • ' • - ' • - ' • " . - " • -

• • • ' . • . ' ' • ' ' ' •

. Tube

: : -"

• | . . ; . - ; ' " . ' ' ' : •Tube •:

• • ' - ' * • - ' . • " • ' : ' • . ' .

;nisry": "^al iea t - X'•'.iaient £:/:*/-•

- • •• . ,• • ' • • -•

Test,•Atmos-•phere

SteamorOxy-gen-Argon

SteamorOxy-gen-Argon

Sotes

Measured•in'-.;' .Vacuum

MeasuredinVacuum

MeasuredinVacmffl

MeasuredinVacuum

i

• " - ' R e s u l t s ' •• -•'"••••".

Increasing change ofcurve above 1000OC; •

Values are higher ttianin item 14

The curve of the oxidizedspecimen shows a parabolicdevelopment

For average time periodsvalue? are E •> 0.7-0.8

::"';ffSsSSgf ••?;%::;

1600 T

1400

1200 I".

1000 - -

ZIROALGY 4

800 -F

E 600

200

REACTION

Zr-Fe EUTECTIC

TUJDC

•a.

LU

LU o

toUJ

INSIDE TEMP., OF TUBE

„_.„ PRESSURIZED WATER4 0 0 ;• BOILING WATER

'-'- .PRESSURIZED WATERBOILING WATEROUTSIDE TEMP, OF TUBE

REACTOR

REACTOR i 320°C

RT (ROOM TEMP )

TCD•z.DC

cc

1

1200°C

600°C

FIG, 1 LIMITS"OF TEMPERATURE RANGE TO CHECK STRESS/STRAINBEHAVIOR pf 2IRCAL0Y-4 SHEATHS') FOLLOWING,^ LOSS

a.

</3

t o

r 10-2

6S0*C

900 °C

0.2 0.31 0.4 0.5 O.fr - 0,7 0,8^

• f ' 1 0F I G r 2 STRESS/STRAIN CURVES FOR ZfRCALOY-V

. HELIUM6.05 mm"' (2^

tlW ' '

VitoUJ

UJ

V)

z

LL)

a:

ZIRCOKIUM - 0.7 8/0 Sn 775°C

0.3 . 0.4- 0.5>~ 6 ' oJ

FIG. 3 STRESS/STRAIN CURVES FOR A Zr-0.7« Sn ALLOY SHOWING THESFfrECT OF THE filSTOUT!ON VELOCJTY ON THJ -Yl EUD SJRESS__AT 775°C3> J "T>," " -

10"

10°

10-'

*

10"2

FIG.'4

I - , - . , ; , - , • " ' • • • •

. . .:: ;. T

L

1

' • ' . . " • . - " • ' : • ' "

v—\\\\

RCALOY-4

Q

\—A—

\\

• SCOTT6>

O 0EMP-475flS)

I WOODS* >

-

-

' i 1 1 -

—

1

1 '

d-

• , 1

p?11

0 300 600 900, 1200 1500 1

ULTIMATE STRESS OP ZIRCALOY-4 IN RELATION

UNDER ISOTHERMAL CONDITIONS*-5«J>, - - * * - -

-< - tF» i

L v^ J

>

-

T

300 (l 2100 -, ,

TO TEMPERATURE

, i^ F

'I.*

10'

• WADDELL e t . a l l }

O H0BS0N e t . a l 8 >

f> EMMERICH e t . a l 9 >

9 HARDY7

1400

FIG, 5 CIRCUMFERENTIAL ULTIMATE STRESS OF ZIRCALOY-4 AS IT ISAFFECTED BY TEMPERATURE UNDER TRANSIENT CONDITIONS1.7.6

1 rf* 5- L

1

UJ

oeC/5touia:a.

as

CCUJ

a

» Ci QC

>- UJo a.«r ixio i—OS— U4fvj CC

o a.

a ui

I*au* ui

—I UJ

<; u.

eg

ain3

U41

Is3ID

I

\- *I f J i

*

* -;

:ro.zti -

' S3

1

X

c

Ii

i A ffWm ^27

1 :^ 2BA^V^

1

>

•

CIRCUMFF

,.. op

HEAT-UP RATE °C/sO 55.5• 27.8A 13.9A 5.5

-

•RFMTIflL

EXPANSION

•>^ B8 /

82

ZIRCAl OY-4

5 = ^ 9

750 800 900 1000 1100 1200 1300 1400

FIG. 7 MAXIMUM INTERNAL PRESSURES ATTAINED IN ZIRCALOY-4 SHEATH IN RELATION TOTEMPERATURE FOR '.lEAT-UP RATES OF 5.5-55.5°C/s'2>

GEMP-475A5)Q . 0 0 5 m t n " 1

900 "1200 1500 1800 „

F IG. 8 ULTIMATE STRESS OF ZIRCALOY-4 PLATE IN A HELIUM" - ATMOSPHERE2-5^ TN RELATION TO THE'D

'\

X"-

10*

103

I/IV .o

LJ

o.I

uJ

10'

10°

10- I

ZIRCAI.OY-4

1720

aIBID

1475A12.5

0 NEITHER BURST NOR EXPANDED 34% —A BURST _O EXPANSION TO 34%

>1374

15

1437+1770 '374_

a

147

3TEMP.

-flUPTURE EXPANSIONr2*1412

7+17

3+92

A25

13361458

1390*71390*7

1208

A11

A28

12/0 , I U

l" •I2401 1072

1110

8

\036 .

25

1038

o

1106 E

32

973 953

1480A .

11.4 1

130

26 30 ^^

•090 103S*H"A A18 i 18.6

1114

O

33

968A33

1058A 1

0.3 , 0.4 0.5 0.7

OtIOOO|270Oll54

1185 _o

1240 -

o1070

1040

1038

1010

A27

0.8

i j ?5*WYi.4 JH|AJHSJJNDER LNTfT EFFETI " T " F^"PRESSURE'(CONVERTEP TO EFFECTIVE STRESS)"AT"DIFFERENT

HEAT-UP RATES"IN ASTEAM ATMOSPHERE2)

1000

o

LU

LU '

4 500 —

I 'i

'» I

11 ,' 0

—

_ < *

•

—

—• t -

2

^~*>-

JRCALOY-4

• !

9 EMER> e t . a l 1 0 )

o HORSOM1 2 )

" l f c^ — .

800 l * 20 40 feO

; ' . ,sl . HEflT UP RATE IN ° C / s .

', F IG . \6 °, RUPTURF, TEMPERATURt BEHAVIOUR IN RELATION TO HEAT-UP RATE,! > ' PRESSURE10) 1.76 kp/mm2 , AT INTERNAL PRESSURE12> 0 ,07

100

AT INTERNAL

HEPT-UP RATE ( °C/s )

FIG. 11 CIRCUMFERENTIAL EXPANSION AT RUPTURE IN RELATION TO INTERNAL PRESSURE AT HEAT-UP RATES

OF 5 .5 -55 .5°C/s .eb l i )

noo

80

40

20

ZIRCA

• %

r i f i

LOY-4

•

o

I 1 1 1

• GEMP-475A5)

O WOODS4}

QP .- •

. i i r i0' - 500 1000

T [°C3

1500

' f\\. 12 :3L0NGATI0N IN RELATION TO TEMPERATURE FOLLOWING TINSILE TESTS ON- ,"---/ ZIRCALOY-4 PLATE IN AN ARGON ATMOSPHERE

O 0,1 .iJiin"1

0.05 roinr1

• 0.005 min"

FIGl,' 13 ' ELONGATION IN RELATiOW fp TEM||RATURE FOLLOWING TENSILE TESTS IN AN7 ARGON ATMOSPHERE AT DIFFERENT blSTdRTION VELOCITIES2^

10*

noo

FIG. 14 MAXIMUM CIRCUMFERENTIAL EXPANSION IN RELATION TO TEMPERATURE" ' " ArAHEAT-UP~WE ffF TKJ6C/V

0.07

' 1° 't I v ^"-i V~" '

cc

<3

O

T

4

O

o

o

40

oo

ooo

o

)MA

Ul

ISOT

h

z

JURE

PER/

E

o•

135-

0

^ >

CD

UJ

U lv*

CO

z<a.XUJ

H-UJCK

U.

oBE

CO

UJH-Ul

COCOUl

ocCL.

1̂UJ _

— E

' 3

ooooo« ; <. i? g

oo- - 2 o

o in

CO

'-: %

14

a.

fc?

'1,I.

F f t . 16 ULTIMATE STRESS CURVES 1SITH A HEAT^UP RATE OF 1OO°C/s7)

TBP0CH " £ a l l u r * teoperatore

FIG. 17 ULTIMATE STRESS CURVES'4>

BRUCH - failure•temperature

ooo

oLUOS

800

8

oo

BSflfi

S

z

CO

jEUJto•«?

1

o

^™* f ?CJ ECo —

»— u .o

t

J

1—

2o

u.UJ

o

'55

u.

UJ

, - . u.''

ECO

—

—

—

— c

- /

1ZIRCALOY-4

.——•-«

1

/

i \

M

1 ' 1

FIG, 19

100 200 . 300 400 500 600 700

•V T

THERMAL EXPANSION COEFFICIENT OF ZIRCALQY-4 SHEATHS

IN A flAMAi DIRECTION6)

r- ^ •'

>~' • fb v 4 r

O O SCOTT6>

J J FEITH1S>

THERMAL C6NDUCTIVITY-OF ZIRCALOY-4(°. l 5- l B> IN RELATION TO TEMPERATURE

,h .' .'

,!>

0.9

0.7

0.5

0.1800

OXIDIZED

1000

ZJRCALOY-4

OXYGEN SATURATED

NOT OXIDIZED

1200 1400

i-i , FIG. 21 OXIDATION EFFECT ON EMISSIVITY OF ZIRCAL0Y-43>

1.0

0.6

0.4

• 850°CA 1000°CO M00°C0 120Q°C

A 1300°C

ZIRGALOY-4

•20 40

: " •• : ;i-tffl.i

80

FIG. 22 EtiilSSIVITY OF ZlRCALOY-4 AS A FUNCTION OF TIME FOR DIFFERENT STEAM TEMPERATURES2>