smart-materials-congress-2019-posters-abstracts

Smart Materials Congress 2019

Nano Research and Applications

ISSN: 2471-9838

Page 44

August 01-02, 2019

Dublin, Ireland

Smart Materials and

Structures

International Conference on

Nano Res Appl 2019, Volume 05

Reactor pressure vessel steel smart behavior as cause of

instability in kinetics of radiation embrittlement

Evgenii Krasikov

National Research Centre “Kurchatov Institute”, Russia

nfluenceofneutronirradiationonreactorpressurevessel

(RPV) steel degradation are examined with reference to

the possible reasons of the substantial experimental data

scatter and furthermore-nonstandard (non-monotonous)

and oscillatory embrittlement behavior. We suppose that

the main factor affecting steel anomalous embrittlement

is fast neutron intensity (dose rate or flux), flux effect

manifestation depends on state-of-the-art fluence level.

At low fluencies radiation degradation has to exceed

normative value, then approaches to normative meaning

and finally became sub normative. Data on radiation

damage change including through the ex-service RPVs

taking into account chemical factor, fast neutron fluence

and neutron flux were obtained and analyzed. In our

opinion, controversy in the estimation on neutron flux

on radiation degradation impact may be explained by

presence of thewavelike component in the embrittlement

kinetics. Therefore flux effect manifestation depends on

fluence level. At low fluencies radiation degradation has

to exceed normative value, then approaches to normative

meaning and finally became sub normative. As,

hypothesis we suppose that at some stages of irradiation

damagedmetal have to be partially restored by irradiation

i.e. neutron bombardment. Nascent during irradiation

nanostructure undergo occurring once or periodically

evolution in a direction both degradation and recovery

of the initial properties. According to our hypothesis

at some stage(s) of metal nanostructure degradation

neutron bombardment became recovering factor. So,

material smart behavior is a cause of instability in kinetics

of radiation embrittlement of the reactor pressure vessel

steel. As a result oscillation arise that in tern lead to

enhanced data scatter.