Accelerators simulation of structure-phase evolution and radiation resistance of materials for nuclear reactors
At this presentation activity of KIPT which during many years was involved into the field of simulation and investigation of Radiation Damage in reactor materials, is described. Well known that charge particle accelerators are widely used for the purpose of obtaining express information on radiat...
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irk-123456789-963202016-03-15T03:02:07Z Accelerators simulation of structure-phase evolution and radiation resistance of materials for nuclear reactors Neklyudov, I. Voyevodin, V. Zelenskiy, V. At this presentation activity of KIPT which during many years was involved into the field of simulation and investigation of Radiation Damage in reactor materials, is described. Well known that charge particle accelerators are widely used for the purpose of obtaining express information on radiation resistance and investigating physical nature of the radiation. During irradiation with charged particle beams one could reproduce and examine under well-controlled conditions practically all the known radiation effects and investigate physical nature of these effects in more detail. Simulation experiments together with results of reactor investigation much contribute to radiation physics phenomena, radiation and ion-beam technologies as well as solving problems of creation low-activated materials with good radiation resistance. Modern status of simulation experiments in investigation of structure-phase transformations in reactor materials during irradiation is discussed. В представленій роботі описано діяльність ХФТІ протягом багатьох років в галузі імітації та дослідженні радіаційного пошкодження реакторних матеріалів. Добре відомо, що прискорювачі заряджених часток широко використовуються з метою отримання експрес-інформації щодо радіаційної стійкості і для вивчення фізичної природи випромінювання. У процесі опромінення пучком заряджених часток можна відтворити та дослідити в добре контрольованих умовах практично всі відомі радіаційні ефекти, а також дослідити фізичну природу цих ефектів більш докладно. Імітаційні експерименти нарівні з реакторними випробуваннями вносять вагомий вклад в явища радіаційної фізики, радіаційні та іонні технології, а також в рішення проблем слабкоактивуємих матеріалів з високою радіаційною стійкістю. Обговорюється сучасний статус імітаційних експериментів в дослідженні структурно-фазових перетворень в реакторних матеріалах під опроміненням. В предлагаемой работе приводится описание деятельности ХФТИ на протяжении многих лет в области имитации и исследования радиационного повреждения реакторных материалов. Хорошо известно, что ускорители заряженных частиц широко применяются с целью получения экспресс-информации о радиационной стойкости и для исследования физической природы излучения. В процессе облучения пучком заряженных частиц можно воспроизвести и исследовать в хорошо контролируемых условиях практически все известные радиационные эффекты, а также исследовать физическую природу этих эффектов более подробно. Имитационные эксперименты наряду с реакторными испытаниями вносят весомый вклад в явления радиационной физики, радиационные и ионные технологии, а также в решение проблем создания слабоактивируемых материалов с высокой радиационной стойкостью. Обсуждается современный статус имитационных экспериментов в исследовании структурно-фазовых превращений в реакторных материалах под облучением. 2009 Article Accelerators simulation of structure-phase evolution and radiation resistance of materials for nuclear reactors / I. Neklyudov, V. Voyevodin, V. Zelenskiy // Вопросы атомной науки и техники. — 2009. — № 4. — С. 7-16. — Бібліогр.: 13 назв. — англ. 1562-6016 http://dspace.nbuv.gov.ua/handle/123456789/96320 en Вопросы атомной науки и техники Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| institution |
Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| collection |
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| language |
English |
| description |
At this presentation activity of KIPT which during many years was involved into the field of
simulation and investigation of Radiation Damage in reactor materials, is described. Well known
that charge particle accelerators are widely used for the purpose of obtaining express information
on radiation resistance and investigating physical nature of the radiation. During irradiation with
charged particle beams one could reproduce and examine under well-controlled conditions
practically all the known radiation effects and investigate physical nature of these effects in more
detail. Simulation experiments together with results of reactor investigation much contribute to
radiation physics phenomena, radiation and ion-beam technologies as well as solving problems
of creation low-activated materials with good radiation resistance. Modern status of simulation
experiments in investigation of structure-phase transformations in reactor materials during
irradiation is discussed. |
| format |
Article |
| author |
Neklyudov, I. Voyevodin, V. Zelenskiy, V. |
| spellingShingle |
Neklyudov, I. Voyevodin, V. Zelenskiy, V. Accelerators simulation of structure-phase evolution and radiation resistance of materials for nuclear reactors Вопросы атомной науки и техники |
| author_facet |
Neklyudov, I. Voyevodin, V. Zelenskiy, V. |
| author_sort |
Neklyudov, I. |
| title |
Accelerators simulation of structure-phase evolution and radiation resistance of materials for nuclear reactors |
| title_short |
Accelerators simulation of structure-phase evolution and radiation resistance of materials for nuclear reactors |
| title_full |
Accelerators simulation of structure-phase evolution and radiation resistance of materials for nuclear reactors |
| title_fullStr |
Accelerators simulation of structure-phase evolution and radiation resistance of materials for nuclear reactors |
| title_full_unstemmed |
Accelerators simulation of structure-phase evolution and radiation resistance of materials for nuclear reactors |
| title_sort |
accelerators simulation of structure-phase evolution and radiation resistance of materials for nuclear reactors |
| publisher |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| publishDate |
2009 |
| url |
http://dspace.nbuv.gov.ua/handle/123456789/96320 |
| citation_txt |
Accelerators simulation of structure-phase evolution and radiation resistance of materials for nuclear reactors / I. Neklyudov, V. Voyevodin, V. Zelenskiy // Вопросы атомной науки и техники. — 2009. — № 4. — С. 7-16. — Бібліогр.: 13 назв. — англ. |
| series |
Вопросы атомной науки и техники |
| work_keys_str_mv |
AT neklyudovi acceleratorssimulationofstructurephaseevolutionandradiationresistanceofmaterialsfornuclearreactors AT voyevodinv acceleratorssimulationofstructurephaseevolutionandradiationresistanceofmaterialsfornuclearreactors AT zelenskiyv acceleratorssimulationofstructurephaseevolutionandradiationresistanceofmaterialsfornuclearreactors |
| first_indexed |
2025-07-07T03:30:56Z |
| last_indexed |
2025-07-07T03:30:56Z |
| _version_ |
1836957362816024576 |
| fulltext |
ВОПРОСЫ АТОМНОЙ НАУКИ И ТЕХНИКИ. 2009. №4-1.
Серия: Физика радиационных повреждений и радиационное материаловедение (94), с. 7-16. 7
ACCELERATORS SIMULATION OF STRUCTURE-PHASE EVOLUTION
AND RADIATION RESISTANCE OF MATERIALS FOR NUCLEAR
REACTORS
I. Neklyudov, V. Voyevodin, V. Zelenskiy
National Science Center “Kharkov Institute of Physics and Technology”,
Kharkov, Ukraine
E-mail: voyev@kipt.kharkov.ua
At this presentation activity of KIPT which during many years was involved into the field of
simulation and investigation of Radiation Damage in reactor materials, is described. Well known
that charge particle accelerators are widely used for the purpose of obtaining express information
on radiation resistance and investigating physical nature of the radiation. During irradiation with
charged particle beams one could reproduce and examine under well-controlled conditions
practically all the known radiation effects and investigate physical nature of these effects in more
detail. Simulation experiments together with results of reactor investigation much contribute to
radiation physics phenomena, radiation and ion-beam technologies as well as solving problems
of creation low-activated materials with good radiation resistance. Modern status of simulation
experiments in investigation of structure-phase transformations in reactor materials during
irradiation is discussed.
INTRODUCTION
Problems of life extension for exploitation
nuclear reactors and development of new type
reactors demand to receive a lot of data for
properties of structure and fuel materials
under irradiation, that practically impossible
without using of accelerators. The problem of
material development for operation in unique
conditions of irradiation and evaluation of
their radiation resistance consists in the use of
existing irradiation facilities for determination
of mechanisms of radiation damage and
selection of materials with high radiation
resistance.
Irradiation of structural materials at
temperature of reactor operation creates the
unprecedented possibility of microstructure
change, of mechanical properties and even of
external dimensions of structural components.
Theses changes are caused by radiation-
induced evolution of microstructure and micro
composition [1–3]. Radiation-induced
phenomena determine the safety, economics
and term of safe operation of reactors of each
type. From all the number of known and
investigated widely phenomena of radiation
damage occurring in the materials during
irradiation with fast particles and radiations, in
the matter of fission and fusion reactor core
structural steels and alloys the principal ones
are:
- dimensional changes (swelling, radiation
growth, radiation creep, surface relief
changing);
- loss in ductility and increase of ductile-
brittle transition temperature;
- oxidation and corrosion process
acceleration during irradiation and under
interaction between the material and heat-
transfer agent, nuclear fuel, transmutation
products;
- erosion of the fusion and fission core
materials surface (blistering, flaking,
sputtering, arcing);
- local and bulk change in chemical
composition of the initial material (radiation-
enhanced segregation of alloy components,
nuclear reactions and fast ion implantation).
Up to now a very big amount of theoretical
and experimental research work has been
devoted to investigation of physical
mechanisms of radiation effects occurring in
materials under irradiation, enormous number
of data on different structural materials
behaviour in thermal and fast reactor cores and
in the installation simulating the environment
of fission and fusion reactors has been
accumulated. However, it is still impossible to
mailto:voyev@kipt.kharkov.ua
explain unambiguously the nature and
regularities of even the principal radiation
phenomena and estimate materials behaviour
under irradiation, since, as distinguished from
ordinary machine-building materials, the
reactor core ones undergo to a great extent
more complex and intensive changes of their
properties as a consequence of radiation
influence.
Now it is evident, that only on the base of
physical nature of interaction between
radiation and materials, mechanisms of
radiation damage in solids one may give
scientifically substantiated recommendations
both on development of new materials or
improvement of existing ones, on evaluation
of their behaviour in reactor core and for
choice of the optimal conditions of operation
of nuclear power systems and the environment,
and as a way of obtaining new materials.
In this paper data are presented on
investigation carried out in KIPT during last
years in the field of simulation of structure-
phase evolution and radiation resistance of
materials with the use of accelerators of
charged particles.
1. METHODOLOGY: ADVANTAGES
AND DISADVANTAGES
For investigations of radiation effects such
as strengthening, embrittlement, creep and
growth of materials one uses high energy
beams of light ions (protons, d-particles, ions
of carbon or nitrogen, etc.), electrons and
gammas to be able to produce homogeneous
defect structure along all the thickness of
irradiated samples. The grain sizes in
austenitic stainless steels are of 20…30 μm.
The maximum thickness of the samples for
mechanical tests must be of 100...250 μm.
Therefore, for these purposes it is necessary to
use charged particle beams with the energy
providing zone of homogeneous damage
through all the irradiated specimen thickness.
For radiation damage physics studies of solids
the high-energy protons and a-particle beams
in cyclotron are used too. The field of
accelerator technology is exciting and dynamic.
As a result the accelerator community is able
to provide brighter light sources, higher
collision rates in particle generation, and more
precise measurements of physical properties.
Higher damage rate as a result of higher cross-
section of charged particles interaction with
materials in accelerators (10-2–10-4 dpa/s) in
comparison with rates of displacements in the
different reactors (10-6-10-8 dpa/s) allow to
achieve necessary doses much faster, for few
hours (Fig. 1).
Fig. 1. Damage rate of fast reactor neutron
and charged particles
Simulation experiments in investigations of
radiation damage of materials have the few
advantages in comparison with reactor tests;
these are:
• precise and good continuous control of
experimental parameters of irradiation
(temperature, flux, etc.);
• possibility of differential and direct
investigation of different factors influence on
structure-phase evolution under irradiation;
ideally suited for optimizing alloying
composition;
• practically absence of induced
radioactivity; specimens can be handled in
conventional conditions;
• relative cheapness of experiments
realization.
Simulation experiments together with
advantages have substantial disadvantages
and limitations:
o difference in recoil spectra and the
structure of primary radiation damage;
o phase stability at high dpa rate- and
increased temperatures - changing of typical
for reactor experiment conditions for
nucleation and growth of voids;
o injected interstitial effect leads for
typical in simulation experiments decreasing
of void size;
8
o difficulties in simulation of trasmutants
accumulation (mainly He and H). This
problem can be solved only with multibeam
accelerators;
o stress induced by irradiation – surface
proximity can go to abnormal evolution of
radiation-induced structure.
2. CHARACTERISTICS OF SOME
RADIATION SOURCES AND
EXPERIMENTAL PROCEDURES
The problem of material development for
operation in unique conditions of irradiation
and evaluation of their radiation resistance
consists in the use of existing irradiation
facilities for determination of mechanisms of
radiation damage and selection of materials
with high radiation resistance.
These experiments may be carried out
under neutron irradiation in existing nuclear
reactors or by irradiation with ions that
generate the processes of radiation damage
which are similar to that expected in reactor of
next generation.
The most of experimental data on physical
nature of radiation effects and radiation
resistance are material examinations in
commercial and research reactors, charged
particle accelerators, and various ion-plasma
machines. Characteristics of some radiation
sources used for studies of radiation effects
and radiation resistance are given in Tabl. 1.
Table 1
The main characteristics of irradiation conditions in the reactors
Reactors and their locations E, MeV Flux density,
Particles/cm2·s
appm He,
dpa T, oC
BOR-60 (Dimitrovgrad) >0.1 3·1015 0.6 360-600
SM-3 (Dimitrovgrad) <0.1
>0.1
5·1015
2·1014 300 200-500
BN-350 (Aktau, closed) >0.1 4·1015 0.5 300-650
BN-600 (Sverdlovsk) >0.1 3·1015 0.5 350-670
Material development programmes needs
high fluence irradiation facility.
Unfortunately now some of intensively
used facilities are shut down (FFTF, DFR,
PFR, EBR-II, ORNL triple beam facility, ANL
1 MeV electron microscope and others). This
was the reason of the situation that some
research programs oriented on the solution of
material science problems were not solved.
Now part of some basic material science
program is realized on accelerators of charged
particles.
KIPT possesses a wide choice of
accelerators (protons, heavy ions, electrons
with different energies spectrum (Fig. 2).
10-2
10-1
100
101
102
103
104
105
106
107
10-9
10-8
10-7
10-6
10-5
10-4
10-3
10-2
10-1
100
E
LI
A
S
(e
- , 3
M
eV
)
L
U
-
10
(e
- , 1
0
M
eV
)
L
U
-
40
(e
- , 4
0
M
eV
)
L
U
-
2
(e
- , 2
20
M
eV
)
ES
U
VI
(N
i,
Fe
, e
tc
. 5
-
10
M
eV
)
VG
-
4;
L
U
M
ZI
(H
e
2.
2
- 4
M
eV
)
VG
-
4
(H
+ 3
M
eV
)
IL
U
-
10
0
(N
i 6
0
ke
V)
IT
ER
B
R
IG
-
30
0
Use rate
Damage zone
D
ep
th
, μ
m
D
os
e
ra
te
, d
pa
/s Maximum rate
Fig. 2. KIPT ion and electron accelerators
Damage efficiency of irradiated particles is
quite difference, that’s why choice of
irradiated particles is very important.
Heavy ions "generate" the highest defect
production rate. But these possess a very short
path lengths (Fig. 3). Therefore, heavy ion
accelerators with beam energies from the
hundreds of keV to a few MeV are mainly
used for producing high levels of defectivity in
thin layers of the irradiated material.
101 102 103 104 105 106 107
10-10
10-8
10-6
10-4
10-2
100
102
104
106
in Ni
Ni-ions
5 MeVCr-ions
3 MeV
Cr-ions
2 MeV
protons
5 MeV
neutrons
E>1MeV
(Fast reactor)
neutrons
E>0.1MeV
(VVER)
C
ro
ss
s
ec
tio
n
dσ
/d
T
(b
ar
n/
at
om
p
ar
tic
le
e
V)
Recoil energy T (eV)
electrons
5 MeV
Fig. 3. Damage Efficiency of different
particles
9
The special research electrostatic
accelerator with external injector (the ESUVT),
which allowed to irradiate the specimens of
mateials by monochrom beams of metals Cr,
Ni, Fe ions with beam energy 2–5 MeV at.
Tirr= 60 to 625 oC [4, 5].
In the KIPT the method of investigation and
evaluation of mechanical properties of the
reactor core materials with the high-energy
electrons and gammas has been proposed.
For investigations of radiation effects such
as strengthening, embrittlement, creep and
growth of materials one uses high energy
beams of light ions (protons, d-particles, ions
of carbon or nitrogen, etc.), electrons and
gammas to be able to produce homogeneous
defect structure along all the thickness of
irradiated samples. The grain sizes in
austenitic stainless steels are of 20…30 μm.
The maximum thickness of the samples for
mechanical tests must be of 100...250 μm.
Therefore, for these purposes it is necessary to
use charged particle beams with the energy
providing zone of homogeneous damage
through all the irradiated specimen thickness.
The used (e,γ)-beams in displacement
production rate do not exceed the neutron
fluxes in reactors but in respect of helium
accumulation the high energy electron- and γ-
beams are more effective than fast neutrons by
two orders of magnitude approximately. This
fact makes it possible to simulate expressly
high temperature radiation (Fig. 4).
Experimental procedures were described
elsewhere [6, 7].
The changes in structure and properties of
solids under irradiation with high-energy
particles and γ-quanta are due to proceeding of
the interconnected physical processes. They
may be subdivided conditionally into:
- the nuclear processes resulting in a
primary knock-on atoms (PKA) generation
and transmutation products (TP) appearance;
- the atomic ones which lead to
displacement cascades development and
emergence of primary regions of point defect
agglomeration;
- "sub structural" processes conducting to
formation of clusters, loops, and nucleation of
voids and new phases;
- the diffusion ones which are responsible
for microstructural evolution, and in the long
run for changing of physical-mechanical
properties of the solids.
a
b
c
Fig. 4. Profiles of primary damages and
segregation of helium (a), along the
fabrication (b) and evalution of the yelding
stress and elongarion (c) in nickel samples,
irradiated by electrons and
γ-quants with energy 225 MeV
The surface effects under irradiation of
first wall .diaphragms, diverter plates and
other units of fusion reactor (sputtering,
blistering, flaking, chemical processes, etc.)
have been predicted. And now they are
investigated by means of (H, D, T, He)-ion
beams with energies ranging from a few keV
to a few MeV, and by the use of various type
plasma machines. The characteristics of the
plasma machines used in the KIPT are given in
Tabl. 2.
It is very difficult during irradiation with
different particles reproduce the conditions
completely even under the use of radiation
sources of the same type. Now for comparison
of irradiation results” criterions of similarity
are used; validity of these conditions is
confirmed by the results of experiments with
irradiation in reactors and in accelerators.
10
Table 2
Facilities for simulation of interaction processes between plasma and materials
Facility
Kind of
ions in
plasma
E, eV Density,
cm-1·s-1 T,°C
Specific
power,
wt/cm2
Purpose
Stellarator
"URAGAN-
2M
H2 100 1013 (during
one impulse) 20 10-1000
Investigations of
dynamics of impu-
rities increase in
plasma and mass
transport in first
wall materials
Plasma facility
“DRAKON”
H+
2,
He+ ,
H+
2+
He+
100
500-1700
1017
1015 100-700 0.1-20
Investigations of
sputtering of ma-
terials, hydrogen
permeability.
Treatment of
cutting tools
Coaxial
accelerator
of plasma
"PROSVET-1"
H+,
He+, Ar+,
(H++0.25
Ar++
0.5He+)
0.2-2000 5·1015-
5·1016 cm-2 20-1200 2·104-107
Modeling of
energetic spectrum
of fusion reactors;
Investigations of
materials surface
erosion
QSPA-Kh-50 H2 200-900 (0.1–7)·1016 cm-3 107
Investigations of
materials behavior
under influence of
high density
plasma
3. MODERN STATUS OF
SIMULATION EXPERIMENTS
The modern status of simulation
experiments is determined by the use of new
types of accelerators (of two and three beams),
of new methods of preparation and study of
specimens (FIB (Focus Ion Beam), Nano-
Indentation Tester, EXAFS (X-ray Absorption
Fine Structure, positron annihilation, nuclear-
physical methods), mathematical modeling
methodology. The use of modern methods
allows remove the restrictions in the use of
results of simulation experiments caused by
low depth of damaged layer.
Briefly main tasks, which are needed in
accelerators using are such:
- Investigation of fundamental processes.
(Simulation of particle collisions;
quantification of kinetic properties of radiation
defects; simulation of formation & growth of
defects; defect characteristics depending on
radiation dose (type, size, density, etc.).
- R&D materials for fast reactors (swelling
and embrittlement). Observation of radiation-
induced microstructure such as segregation
and hardening.
- Microstructural predicting for possibilities
of life extension for operation reactors; RPV
steels (dpa rate), RVI (low temperature
embrittlement).
- Gases influence on mechanisms of
radiation damage. Synergetic effect of helium
and hydrogen in fusion and spallation systems.
3.1. Pressure vessel steels
Accelerators using for experiments of
radiation resistance and life extension for
pressure vessel steels and pressure vessel
internals are now in progress. On the base of
the results of investigation of contrast of
electron-microscopic images of dislocation
loops formed under irradiation in matrix of
pressure vessel steel A533B irradiated by Ni
ions (3 MeV) to the dose of 1 dpa at 290 oC it
was detected that majority of loops has
Burgers vector b=a <100> (Fig. 5) [8].
11
a b
Fig. 5. Dislocation loops images in different diffraction conditions: a - g=020; b - g=200 [8]
Total number of point defects produced
under irradiation to the dose 1 dpa is 8·1028 m-3
and the concentration of point defects
contained in visible dislocation loops
represents only low fraction of the total
number) ~2·10-5 m-3. It means that the
recombination between vacancies and
interstitial is the dominating process in steels
A533 irradiated by ions with a dose of
10-4 dpa/s.
Using of simulation experiments for
investigation of radiation behavior of pressure
vessel steels was limited but now application
of modern experimental facilities (HREM, 3D
tomographe) gave a chance to study behavior
of matrix defects and distribution of elements
and impurities during irradiation.
3.2. Influence of dose rate on void
swelling
The temperature dependency of steel
swelling (Fig. 6) has the characteristic bell-like
appearance and reveals a displacement by
25 K to higher temperatures during the
variation of dose rate from 10-3 to 10-2 dpa·s-1.
It must be noted that the behaviour of the
swelling curve in the rising area (low
temperature range of swelling) is more
extended at a dose rate of 10-3 dpa·s-1 in
comparison with 10-2 dpa·s-1. The influence of
dose rate is manifested in the duration of the
transient period of swelling and is more
defined at lower temperatures. Irradiation at
888 K leads to a considerably lower influence
of dose rate.
Comparison of typical dose rates of 10-3–
10-2 dpa·s-1 used in the presented investigation
and 10-9–10-8 dpa·s-1 which are typical for
VVER reactor internals allows concluding that
the damage level corresponding to the start of
swelling will not exceed 20 dpa. This
assumption confirms the results which are
obtained in experiments on the BOR-60
reactor [9].
Fig. 6. Temperature dependence of swelling of
solution-annealed stainless steel 18Cr-10Ni-Ti
(Dose = 50 dpa). The dose rates are:
1·10-3 dpa⋅s-1 (■) and 1·10-2 dpa⋅s-1 (●);
a - and b – dose dependence of swelling at
Tirr = 863 and Tirr = 888 K, respectively
3.3. Zr-base alloys
The necessity of provision of fuel elements
burn up to 75–80 GVt d/t U is related with the
increase of the temperature of FE claddings to
358 ºC and with vapor content in coolant to
13% mass. Here the main mechanisms of
degradation will be the radiation growth and
hydride formation. First report on microscopic
evolution of Zr hydride in Zircalloy-4 was
done as result of simulation experiments,
which was performed in Tokyo University
[10] (Fig.7).
12
a b c
Fig. 7. Growth of a intra-granular Zr hydride in Zircaloy-4 specimen under 150 keV H2
+
irradiation, B=z=[0001], g = 0110 up to 1.5·1015 (a), 4.0·1015 (b) and 4.8·1015 ions/cm2 (c) [10]
The precipitation process of Zr hydride in
Zircaloy-4 investigated by in-situ TEM
observation under hydrogen ion irradiation.
The dynamic process of the formation of Zr
hydrides accompanied with dislocations
around hydrides was observed. The
observation was conducted on (0001) basal
plane, which is usually the habit plane of Zr
hydrides, and the hydride was the γ-hydride
phase with fct structure and the orientation
relationship was <110>γ || <1120>α as
reported previously. As the hydride grew, the
dislocation was generated gradually.
3.4. The synergistic effect of radiation
damage and helium + hydrogen
Last time it is shown very complex and
synergetic influence of radiation damage,
hydrogen and helium (for different reactor
conditions are) on materials of PVI internals of
VVER and PWR-type reactors. Comparatively
low dose rate and swelling temperature shift
to area of low temperatures together with
production of He and H as result of
transmutation reactors can be responsible for
low temperature swelling and connected with
it low temperature embrittlement. Influence of
helium and hydrogen on nanostructural
changes in steels of ferritic/martemsitic class
was investigated on three-beam accelerator,
based on the currently operating electrostatic
heavy ion accelerator ESUVI, located in the
Kharkov Institute of Physics and Technology.
The substitution of deuterium for protium
allows the use of nuclear reactions to
determine the depth distribution and
concentration of hydrogen isotopes. By
processing depth distribution profiles the
values of deuterium retention were obtained.
The temperature dependences of deuterium
retention are shown in Fig. 8. With
preliminary implantation of inert gases of
helium or argon, formation of radiation defects
practically all deuterium implanted at Troom is
trapped in the investigated steels. Temperature
of deuterium detrapping from the specimen
shifts by 200 K to higher temperature.
0
2
4
6
8
10
12
300 400 500 600 700 800
Temperature (K)
D
re
ta
in
ed
(x
10
16
D
/c
m
2 )
only D
1×1016D/cm2
damage + D
1×1016D/cm2
Fig. 8. Quantity of deuterium trapped in steels
EI-852 with deuterium implanted to the dose
1·1016cm-2 without and with preliminary
implanted to dose 5·1016cm-2 argon
So, the synergistic effect of displacement
damage, helium and hydrogen atoms can
enhance the irradiation-induced degradation.
Such effects were observed in a number of
investigations. The highest swelling has been
observed in ferritic model alloys of Fe-Cr
under triple ion irradiation. In vanadium
alloys, simultaneous irradiation of Ni, He and
H ions enhanced cavity formation and
swelling. The synergistic effect of He and H
irradiation in these alloys and F82H
martensitic steel was confirmed by the
occurrence of larger cavities and higher
swelling under triple ion irradiation as
compared with dual ion irradiations [11].
3.5. The investigation of prospective
structural materials
Achievement of high burn-out (20–25 % of
h.a.) in fast reactors demands to solve swelling
problem of cladding’s and wrapper’s materials.
Void swelling up to now is the main limiting
13
factor for using structural materials for fast
reactors and reactors of future generations [12].
At this area using advantages of accelerators is
much more productive because allow
methodically investigate the input of different
factors, which influence on voids nucleation
and growth. Many of them were investigated-
role of structure-phase evolution, influence of
crystal lattice, gaseous impurities etc. [1, 3].
Role of different alloying elements in radiation
behaviour of cladding for fuel elements was
investigated (Fig. 9) [13].
200 300 400 500 600 700
0,0
0,4
0,8
1,2
1,6
2,0
5
4
3
2
1
Sw
el
lin
g,
%
Temperature, ОС
a b
Fig. 9. Temperature dependence of swelling for: austenitic steels (EP-172, EK-164) (a);
some iron based materials (b): 1 - α-Fe (D=100 dpa); 2 - EP-450 (D=150 dpa);
3 - Fe-12%Cr (D=100dpa); 4 - 01X13M4 Cr3+ (D=100 dpa); 5 - 01X13M4 Ar3+
(D=100 dpa)
In nuclear power technology of following
generation (Generation 4) the using of charged
particles accelerators (electrons or protons) for
energy from 100 to 1000 MeV is supposed for
generation of neutrons. Energy spectrum of
emitted neutrons reaches energies 100 and
more MeV and cross-sections of nuclear
reactions of transmutation (n,2n), (n, p) and (n,
α) increases; due to this fact the rate of
transmutation variation of steels element
composition and level of transmutation
formation of gaseous transmutants increases.
Damage of structural materials of
electronuclear systems develops as result of
irradiation by high-energy protons and
neutrons and increases under the influence of
liquid metals and possibly of other coolants.
Such damage is similar to the damage in (d, t)
fusion reactors but transmutation effects
(production of H and He) are more
pronounced.
Various international programs are now
underway to develop advanced reactor
concepts under the umbrella of the Generation
4 and INPRO efforts. Each of these programs
envisions the use of ferritic-martensitic steels
with exposure levels of ~100–200 dpa and
temperatures reaching as high as 650–750 ºC,
and in many cases with concurrent generation
of exceptionally high levels of helium and
hydrogen.
4. THE THREE-ION SINGLE BEAM
DEVICE
Based on the availability of a currently-
existing accelerator STCU project “Evaluation
of the performance of ferritic-martensitic steel
s under gas conditions relevant to advanced
reactor concepts” will first complete the
development and improvement of a special ion
irradiation system that will provide a state-of-
art irradiation test facility. This facility will be
used to determine the full parametric
performance of all ferritic-martensitic steels
currently being developed in the world
community for advanced reactor applications
(STSU Project #3663). This facility will allow
irradiation to proceed under gas generation
conditions specific to each reactor concept,
using iron ions to generate radiation damage
without gas, but also allowing co-implantation
of both helium and hydrogen at reactor-
specific levels, using a new, novel concept of a
three-ion single beam rather than the usual
three-accelerator (Fig. 10 a, 10 b).
14
0,0 0,2 0,4 0,6 0,8 1,0 1,2
0
20
40
60
80
100
120
implanted ion
distribution (Cr ion)
implanted ion distribution
(H2 ion 60 keV)
D
os
e,
d
pa
Depth, μm
investigated
zone
damage profile
(Cr ion, 2MeV)
implanted ion distribution
(He ion 120 keV)
Fig. 10 a. Ions distribution of He, H, Cr and
damage profile by Cr ions under irradiation
of Fe (TRIM-92)
Fig. 10 b. Schematic illustration of the three-ion
single beam device to be used in the proposed
project
5. CONCLUSIONS
Nuclear energy renaissance demands
renaissance in research and development of
nuclear materials which determine the safe and
economical operation of exploitated and
developed nuclear facilities.
Material development programmes needs
high fluence irradiation facilities.
Unfortunately last time irradiation possibilities
were strongly decreased due to shut down of
few nuclear facilities. Now simulation
experiments are very useful for evaluation of
radiation behaviour of materials, which work
in different facilities with different spectral
conditions.
KIPT during many years was involved into
the program of simulation of radiation damage
in reactor materials. Results received during its
performing show that irradiation with charged
particle beams allows reproduce and
investigate in controlled conditions practically
all the known radiation effects in fission and
fusion reactor materials and investigate their
physical nature more completely and reliably.
Carrying out of research programs in
charged particle accelerators together with
reactor tests results allow to speed up
significantly the studies of mechanisms of
radiation phenomena, their connection with
irradiation and structural parameters, to reveal
many of their regularities, to make selection
and development of radiation-resistant
materials.
Acknowledgement to co-authors of this
presentation A. Dovbnya, L. Ozhigov, V. Bryk,
B. Shilyaev, A. Parkhomenko, O. Borodin,
Y. Petrusenko, G. Tolstolutskaya, R. Vasi-
lenko, A. Kalchenko etc.
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N. Sekimura. In-situ TEM observation of
pcecipitation of zirconium hydrides in
Zircaloy-4 under hydrogen iron implantation //
Materials Science Forum. 2007, v. 561-565,
p. 1765-1768.
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T. Aruga, M. Ando, H. Tanigawa, T. Taguchi,
T. Sawai, K. Oka, S. Ohnuki. Swelling
behavior of F82H steel irradiated by triple/dual
ion beams // J. Nucl. Mater. 2003, v. 318,
p. 267-273.
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v. 10 A. Nuclear Materials / Ed., R.W. Cahn,
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ИМИТАЦИЯ СТРУКТУРНО-ФАЗОВОЙ ЭВОЛЮЦИИ ПРИ ПОМОЩИ
УСКОРИТЕЛЕЙ И РАДИАЦИОННОЕ СОПРОТИВЛЕНИЕ МАТЕРИАЛОВ
ДЛЯ ЯДЕРНЫХ РЕАКТОРОВ
И. Неклюдов, В. Воеводин, В. Зеленский
В предлагаемой работе приводится описание деятельности ХФТИ на протяжении
многих лет в области имитации и исследования радиационного повреждения реакторных
материалов. Хорошо известно, что ускорители заряженных частиц широко применяются с
целью получения экспресс-информации о радиационной стойкости и для исследования
физической природы излучения. В процессе облучения пучком заряженных частиц можно
воспроизвести и исследовать в хорошо контролируемых условиях практически все
известные радиационные эффекты, а также исследовать физическую природу этих
эффектов более подробно. Имитационные эксперименты наряду с реакторными
испытаниями вносят весомый вклад в явления радиационной физики, радиационные и
ионные технологии, а также в решение проблем создания слабоактивируемых материалов
с высокой радиационной стойкостью. Обсуждается современный статус имитационных
экспериментов в исследовании структурно-фазовых превращений в реакторных
материалах под облучением.
ІМІТАЦІЯ СТРУКТУРНО-ФАЗОВОЇ ЕВОЛЮЦІЇ ЗА ДОПОМОГОЮ
ПРИСКОРЮВАЧІВ ТА РАДІАЦІЙНА СТІЙКІСТЬ МАТЕРІАЛІВ
ДЛЯ ЯДЕРНИХ РЕАКТОРІВ
І. Неклюдов, В. Воєводін, В. Зеленський
В представленій роботі описано діяльність ХФТІ протягом багатьох років в галузі
імітації та дослідженні радіаційного пошкодження реакторних матеріалів. Добре відомо,
що прискорювачі заряджених часток широко використовуються з метою отримання
експрес-інформації щодо радіаційної стійкості і для вивчення фізичної природи
випромінювання. У процесі опромінення пучком заряджених часток можна відтворити та
дослідити в добре контрольованих умовах практично всі відомі радіаційні ефекти, а також
дослідити фізичну природу цих ефектів більш докладно. Імітаційні експерименти нарівні з
реакторними випробуваннями вносять вагомий вклад в явища радіаційної фізики,
радіаційні та іонні технології, а також в рішення проблем слабкоактивуємих матеріалів з
високою радіаційною стійкістю. Обговорюється сучасний статус імітаційних
експериментів в дослідженні структурно-фазових перетворень в реакторних матеріалах
під опроміненням.
16
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