Study of Radiation Effect on RPV Steel

Asian Physics Symposium 2007 Bandung

Study of Radiation Effect on Study of Radiation Effect on RPV Steel Using Monte RPV Steel Using Monte

Carlo MethodCarlo Method

Topan Setiadipura, Elfrida Saragi, Topan Setiadipura, Elfrida Saragi, Khairina NsKhairina Ns

[email protected]@batan.go.id

Computational DivisionComputational DivisionCenter for Development of Nuclear Center for Development of Nuclear

Informatics Informatics BATAN –INDONESIABATAN –INDONESIA


PreviewPreview

ObjectiveObjective Introduction:Introduction:

- radiation damage issue of RPV- radiation damage issue of RPV- multiscale computing- multiscale computing

Computational MethodComputational Method- Monte Carlo or MCNP model- Monte Carlo or MCNP model- Tally - Tally

ResultsResults Conclusion and DiscussionConclusion and Discussion


ObjectiveObjective

To demonstrate the application of To demonstrate the application of monte carlo method as particle monte carlo method as particle transport and reaction simulation in transport and reaction simulation in radiation effect simulation.radiation effect simulation.

As preliminary calculation of nuclear As preliminary calculation of nuclear parameter in material subjected to parameter in material subjected to neutron irradiation.neutron irradiation.


IntroductionIntroduction The safety of commercial light-water The safety of commercial light-water

reactors is highly dependent on the reactors is highly dependent on the structural integrity of the RPV. The structural integrity of the RPV. The degrading effects of neutron degrading effects of neutron irradiation on carbon and low-alloy irradiation on carbon and low-alloy pressure vessel steels have been pressure vessel steels have been recognized and investigated since the recognized and investigated since the early 1950s. early 1950s.

• • In those steels at RPV operating In those steels at RPV operating temperatures (260~288temperatures (260~288°°C), radiation C), radiation damage is produced when neutrons damage is produced when neutrons of sufficient energy displace atoms of sufficient energy displace atoms from their lattice sites. from their lattice sites.


Introduction (cont’d)Introduction (cont’d)

• • The synergistic The synergistic effects of neutron effects of neutron fluence, flux, and fluence, flux, and spectrum, the spectrum, the irradiation irradiation temperature, and the temperature, and the chemical composition chemical composition and microstructure and microstructure of the steel must be of the steel must be understood to reduce understood to reduce the uncertainties the uncertainties associated with the associated with the development of development of predictive models of predictive models of embrittlement.embrittlement.


Multiscale Physics and ModellingMultiscale Physics and Modelling

An illustration of the sequence of basic embrittlement processes: (a) creation of primary radiation damage defects: (b) formation of nanoscale solute and defect clusters (iron atoms not shown); (c) pinning of dislocations and hardening by nanofeatures; (d) hardening enhanced cleavage fracture; at a (e) stress concentration.


Monte Carlo MethodMonte Carlo Method

Simulation approach to Simulation approach to particle transport :particle transport :

““Faithfully simulate the hystory of a Faithfully simulate the hystory of a single particle from birth to death.single particle from birth to death.

Random walk for single Random walk for single particleparticle

- Model collisions using physics - Model collisions using physics equations & cross-section data.equations & cross-section data.

- Model free-flight between collisions - Model free-flight between collisions using computational geometry.using computational geometry.

- Tally the occurences of events in - Tally the occurences of events in each regioneach region

- Save any secondary particle, - Save any secondary particle, analyze them later.analyze them later.


Track Length Estimate of Cell Flux Track Length Estimate of Cell Flux (F4 Tally)(F4 Tally)

The quantity The quantity NN(r,(r,EE,,tt))ds ds may be thought of as may be thought of as a track length density; thus, the average flux a track length density; thus, the average flux can be estimated by summing track lengths. can be estimated by summing track lengths.


Material CompositionMaterial Composition

Material C Si Mn P S Ni Cr Cu Mo Fe density

JRQ 0.18 0.24 1.42 0.017 0.004 0.84 0.12 0.14 0.51 96.529 7.765087

Steel A 0.19 0.3 1.3 0.015 0.01 0.68 0.17 0.16 0.53 96.645 7.750524

Steel B 0.19 0.19 1.43 0.004 0.001 0.65 0.13 0.04 0.5 96.865 7.771709

Steel L 0.17 0.24 1.36 0.003 0.003 0.61 0.07 0.02 0.47 97.054 7.768824


ResultsResultsNeutron Fluence Distribution

5.20E-03

5.40E-03

5.60E-03

5.80E-03

6.00E-03

6.20E-03

6.40E-03

6.60E-03

1 3 5 7 9 11 13 15 17 19

Depth/layer

JRQ

Steel L


Distribution of (n,H) reaction

3.70E-053.80E-053.90E-054.00E-054.10E-054.20E-054.30E-054.40E-054.50E-054.60E-054.70E-05

1 3 5 7 9 11 13 15 17 19

Depth/layer

JRQ

Steel L


Distribution of (n,gamma) reaction

2.30E-072.40E-072.50E-072.60E-072.70E-072.80E-072.90E-073.00E-073.10E-07

Depth/layer

JRQ

Steel L


Distribution of (n,d) reactions

1.40E-06

1.45E-06

1.50E-06

1.55E-06

1.60E-06

1.65E-06

1.70E-06

1.75E-06

1 3 5 7 9 11 13 15 17 19

Depth/layer

JRQ

Steel L


Distribution of (n,alpha) reactions

1.05E-05

1.10E-05

1.15E-05

1.20E-05

1.25E-05

1.30E-05

1.35E-05

1 3 5 7 9 11 13 15 17 19

Depth/layer

JRQ

Steel L


Total Cross SectionTotal Cross Section


Elastic Cross SectionElastic Cross Section


Absorption Cross SectionAbsorption Cross Section


ConclusionConclusion Preliminary calculation have been performed by Monte Preliminary calculation have been performed by Monte

Carlo method using the continous energy MCNP 5 transport Carlo method using the continous energy MCNP 5 transport code to determine the nuclear parameters in the RPV steel code to determine the nuclear parameters in the RPV steel as an effect of neutron radiation.as an effect of neutron radiation.

The parameters include the high energy neutron fluence The parameters include the high energy neutron fluence distribution, the defect production in form of H,D, and He distribution, the defect production in form of H,D, and He atoms, photon production and primary knock-on atoms, atoms, photon production and primary knock-on atoms, nuclear heating, yield of the nuclear reaction on certain nuclear heating, yield of the nuclear reaction on certain isotop.isotop.

Further calculation to determine the primary damage and Further calculation to determine the primary damage and its transport/diffusion on the steel because of the neutron its transport/diffusion on the steel because of the neutron radiation is needed.radiation is needed.

Further analyses of the effect of each particle resulted Further analyses of the effect of each particle resulted haven’t been discussed, it need a co-operation with other haven’t been discussed, it need a co-operation with other division.division.

Study of Radiation Effect on RPV Steel

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