Jaakko Leppänen

2023

A New Stochastic Geometry Type Based on Voronoi Tessellation in the Serpent 2 Monte Carlo Code

Leppänen, J., 2023, Proceedings of M&C 2023 International Conference on Mathematics and Computational Methods Applied to Nuclear Science and Engineering. 8 p.

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

Open Access

2022

3D Spherical Functional Expansion Tallies in Serpent 2 Monte Carlo Code

Jambrina, A. (Corresponding author) & Leppänen, J., 20 May 2022, Proceedings of the International Conference on Physics of Reactors (PHYSOR 2022). American Nuclear Society (ANS), p. 276-283

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

1 Citation (Scopus)

An Inline Burn-up Algorithm: Proposal and Preliminary Analysis

Cosgrove, P. (Corresponding author), Shwageraus, E. & Leppänen, J., 20 May 2022, Proceedings of the International Conference on Physics of Reactors (PHYSOR 2022). American Nuclear Society (ANS), p. 2256-2265 10 p.

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

District Heating Reactor LDR-50: Thermal-Hydraulic Analysis of Difficult Load Following Cases

Komu, R., Lindroos, T. J., Hillberg, S. & Leppänen, J., 2022, 13th International Topical Meeting on Nuclear Reactor Thermal-Hydraulics, Operation and Safety (NUTHOS 13). p. 1260-1271 12 p. N13P160

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

EcoSMR - Ecosystem for Small Modular Reactors

Häkkinen, S., Lindroos, T. J., Soppela, O., Leppänen, J., Tulkki, V. & Suikkanen, H., Nov 2022, Nuclear Science and Technology Symposium - SYP2022. Helsinki: Finnish Nuclear Society, 4 p.

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

Open Access

Load Follow Simulations for the LDR-50 District Heating Reactor Using the Kraken Computational Framework

Leppänen, J., Valtavirta, V. & Komu, R., 20 May 2022, Proceedings of the International Conference on Physics of Reactors (PHYSOR 2022). American Nuclear Society (ANS), p. 3284-3293 10 p.

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

1 Citation (Scopus)

Station Blackout Transient Analyses for VTT’s SMR Design LDR-50

Komu, R., Hillberg, S. & Leppänen, J., 2022, Nuclear Science and Technology Symposium (SYP) Proceedings. Finnish Nuclear Society, 4 p.

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

Open Access

2021

A finnish district heating reactor: Neutronics design and fuel cycle simulations

Leppänen, J., Valtavirta, V., Tuominen, R., Rintala, A. & Lauranto, U., 19 Oct 2021, 28th International Conference on Nuclear Engineering: Operating Plant Challenges, Successes, and Lessons Learned; Nuclear Plant Engineering; Advanced Reactors and Fusion; Small Modular and Micro-Reactors Technologies and Applications. American Society of Mechanical Engineers (ASME), Vol. 1. 8 p. V001T04A010. (International Conference on Nuclear Engineering (ICONE), Vol. 28).

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

6 Citations (Scopus)

A Finnish district heating reactor: Thermal-Hydraulic Design and Transient Analyses

Komu, R. (Corresponding author), Hillberg, S., Hovi, V., Leppänen, J. & Leskinen, J., 2021, Proceedings of the 2021 28th International Conference on Nuclear Engineering: Operating Plant Challenges, Successes, and Lessons Learned; Nuclear Plant Engineering; Advanced Reactors and Fusion; Small Modular and Micro-Reactors Technologies and Applications. American Society of Mechanical Engineers (ASME), Vol. 1. 7 p. V001T04A006. (International Conference on Nuclear Engineering (ICONE), Vol. 28).

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

7 Citations (Scopus)

A Finnish District Heating Reactor: Background and General Overview

Leppänen, J. (Corresponding author), Hillberg, S., Hovi, V., Komu, R., Kurki, J., Lauranto, U., Oinonen, A., Peltonen, J., Rintala, A., Tulkki, V., Tuominen, R. & Valtavirta, V., 2021, Proceedings of the 2021 28th International Conference on Nuclear Engineering: Operating Plant Challenges, Successes, and Lessons Learned; Nuclear Plant Engineering; Advanced Reactors and Fusion; Small Modular and Micro-Reactors Technologies and Applications. American Society of Mechanical Engineers (ASME), Vol. 1. 8 p. V001T04A009. (International Conference on Nuclear Engineering (ICONE), Vol. 28).

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

6 Citations (Scopus)

A Novel Monte Carlo Leakage Correction for Serpent 2

Valtavirta, V. (Corresponding author) & Leppänen, J., 2021, Mathematics & Computation (M&C) 2021. American Nuclear Society (ANS), p. 540-548 50026. (Transactions of the American Nuclear Society; No. 3141).

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

Direct Calculation of Safety-Related Parameters for Coupled Transients Using Monte Carlo Neutronics Plus Subchannel Thermal-Hydraulics

Ferraro, D. (Corresponding author), García, M., Valtavirta, V., Imke, U., Tuominen, R., Leppänen, J. & Victor, S.-E., 2021, Mathematics & Computation (M&C) 2021. American Nuclear Society (ANS), p. 549-558 50027. (Transactions of the American Nuclear Society; No. 3141).

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

Enabling Large-Scale Depletion in Serpent 2 Monte Carlo Code by Collision-Based Domain Decomposition

Jambrina, A. (Corresponding author), Leppänen, J. & García, M., 2021, Mathematics & Computation (M&C) 2021. American Nuclear Society (ANS), p. 88-99 49983. (Transactions of the American Nuclear Society; No. 3141).

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

Functional Expansion Tally-Based Shannon-Fisher Complexity Metric for Fission Source Convergence Analysis in Serpent 2 Monte Carlo Code

Jambrina, A. (Corresponding author) & Leppänen, J., 2021, Mathematics & Computation (M&C) 2021. American Nuclear Society (ANS), p. 249-255 49998. (Transactions of the American Nuclear Society; No. 3141).

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

General Formulation of Functional Expansion Tallies for Regular 2D Geometries in Serpent 2 Monte Carlo Code

Jambrina, A. (Corresponding author) & Leppänen, J., 2021, Mathematics & Computation (M&C) 2021. American Nuclear Society (ANS), p. 239-248 49997. (Transactions of the American Nuclear Society; No. 3141).

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

Radiation Shielding Calculations at VTT Centre for Nuclear Safety Using the Serpent 2 Monte Carlo Code

Leppänen, J. (Corresponding author) & Jokipii, M., 2021, Mathematics & Computation (M&C) 2021. American Nuclear Society (ANS), p. 520-529 50024. (Transactions of the American Nuclear Society; No. 3141).

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

2020

A Subchannel Coarsening Method for Serpent 2-SUBCHANFLOW Applied to a Full-Core VVER Problem

Garcia, M. (Corresponding author), Ferraro, D. (Corresponding author), Valtavirta, V., Tuominen, R., Imke, U., Mercatali, L., Victor, S.-E. & Leppänen, J., 2020, PHYSOR 2020: Transition to Scalable Nuclear Energy. 8 p.

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

Open Access

Serpent/SUBCHANFLOW Coupled Calculations for a VVER Core at Hot Full Power

Ferraro, D. (Corresponding author), Garcia, M., Imke, U., Valtavirta, V., Tuominen, R., Bilodid, Y., Leppänen, J. & Victor, S.-E., 2020, PHYSOR 2020 - International Conference on Physics of Reactors: Transition to a Scalable Nuclear Future. Margulis, M. & Blaise, P. (eds.). EDP Sciences, p. 721-728 (EPJ Web of Conferences, Vol. 247).

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

Open Access

1 Citation (Scopus)

2019

Development and test of a hybrid probabilistic-deterministic framework based on the interface current method

Yi, H., Demazière, C., Vinai, P. & Leppänen, J., 2019, International Conference on Mathematics and Computational Methods Applied to Nuclear Science and Engineering, M and C 2019. American Nuclear Society (ANS), p. 2166-2177 12 p.

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

Energy-dependent fission yields in advanced reactors

Kunchev, T., Shwageraus, E. & Leppänen, J., 1 Jan 2019, International Conference on Mathematics and Computational Methods Applied to Nuclear Science and Engineering, M and C 2019. American Nuclear Society (ANS), p. 710-718 9 p.

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

1 Citation (Scopus)

Global variance reduction scheme with self-adaptive weight-window mesh in the Serpent 2 Monte Carlo Code

Leppänen, J. & Jokipii, M., 2019, International Conference on Mathematics and Computational Methods Applied to Nuclear Science and Engineering, M and C 2019. American Nuclear Society (ANS), p. 85-95 11 p.

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

3 Citations (Scopus)

Kraken: An upcoming Finnish reactor analysis framework

Valtavirta, V. (Corresponding author), Hovi, V., Loukusa, H., Rintala, A., Sahlberg, V., Tuominen, R. & Leppänen, J., 2019, International Conference on Mathematics and Computational Methods Applied to Nuclear Science and Engineering, M and C 2019. American Nuclear Society (ANS), p. 786-795 10 p.

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

Radiation transport capabilities in the Serpent 2 Monte Carlo code

Leppänen, J., 2019, Proceedings: 28th International Conference Nuclear Energy for New Europe, NENE 2019.

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

Serpent and TRIPOLI-4® transient calculations comparisons for several reactivity insertion scenarios in a 3D PWR minicore benchmark

Ferraro, D., Faucher, M., Mancusi, D., Zoia, A., Valtavirta, V., Leppänen, J. & Sanchez-Espinoza, V. H., Aug 2019, International Conference on Mathematics Computational Methods and Reactor Physics (M&C 2019). American Nuclear Society (ANS), p. 1734-1743 10 p.

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

7 Citations (Scopus)

Serpent validation using giacint facility experimental data from a control rod insertion transient

Talamo, A., Gohar, Y. A., Valtavirta, V., Leppänen, J., Sikorin, S., Mandzik, S., Polazau, S. & Hryharovich, T., Aug 2019, International Conference on Mathematics Computational Methods and Reactor Physics (M&C 2019). American Nuclear Society (ANS), p. 2657-2663 7 p.

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

2018

Application of the Serpent–OpenFOAM Coupled Code System to the SEALER Reactor Core

Tuominen, R. (Corresponding author), Valtavirta, V. & Leppänen, J., 2018, International Conference on Physics of Reactors (PHYSOR 2018): Reactor Physics Paving the Way Towards More Efficient Systems. Cancun: American Nuclear Society (ANS)

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

Assessment of Serpent Cross Sections of the Second Generation Fuel of TVEL for Loviisa NPP

Kuopanportti, J. (Corresponding author), Leppänen, J. & Saarinen, S., 2018, International Conference on Physics of Reactors (PHYSOR 2018): Reactor Physics Paving the Way Towards More Efficient Systems . American Nuclear Society (ANS), p. 1969-1981

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

Development of a spatial domain decomposition scheme for Monte Carlo neutron transport

García, M., Ferraro, D., Sanchez-Espinoza, V. H., Mercatali, L., Leppänen, J. & Valtavirta, V., Nov 2018, 26th International Conference on Nuclear Engineering: Nuclear Fuel and Material, Reactor Physics, and Transport Theory. American Society of Mechanical Engineers (ASME), Vol. 3. 7 p. ICONE26-82144

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

2 Citations (Scopus)

Effects of fuel temperature history approximations on neutronics properties of a BWR assembly

Valtavirta, V. & Leppänen, J., 2018, International Conference on Physics of Reactors (PHYSOR 2018): Reactor Physics Paving the Way Towards More Efficient Systems . American Nuclear Society (ANS), p. 2215-2226 12 p.

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

Foreseen capabilities, bottlenecks identification and potential limitations of serpent MC transport code in large-scale full 3-D burnup calculations

Ferraro, D., Garcia, M., Mercatali, L., Sanchez Espinoza, V. H., Leppänen, J. & Valtavirta, V., Nov 2018, 26th International Conference on Nuclear Engineering: Nuclear Fuel and Material, Reactor Physics, and Transport Theory. American Society of Mechanical Engineers (ASME), Vol. 3. 9 p. ICONE26-82305

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

7 Citations (Scopus)

New stochastic substep based burnup scheme for Serpent 2

Valtavirta, V. & Leppänen, J., 2018, International Conference on Physics of Reactors (PHYSOR 2018): Reactor Physics Paving the Way Towards More Efficient Systems . American Nuclear Society (ANS), p. 523-534

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

2017

Implementation of weighted delta-tracking with scattering in the serpent 2 monte carlo code

Rehak, J. S. (Corresponding author), Kerby, L. M., Dehart, M. D., Slaybaugh, R. N. & Leppänen, J., 1 Jan 2017, 2017 Annual Meeting. American Nuclear Society (ANS), Vol. 116. p. 548-551 (Transactions of the American Nuclear Society, Vol. 116).

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

Open Access

2016

Calculating neutron dosimeter activation in VVER-440 surveillance chains with Serpent

Viitanen, T. & Leppänen, J., 2016, 26th Symposium of AER on VVER Reactor Physics and Reactor Safety : Book of Abstracts. Hungarian Academy of Sciences Centre for Energy Research, p. 181-188

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific

Coupling Serpent and OpenFOAM for neutronics - CFD multi-physics calculations

Tuominen, R., Valtavirta, V., Peltola, J. & Leppänen, J., 2016, PHYSOR 2016: Unifying Theory and Experiments in the 21st Century. American Nuclear Society (ANS), p. 255-269

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

Open Access

27 Citations (Scopus)

Delayed Neutron Emission Model for Time Dependent Simulations with the Serpent 2 Monte Carlo Code: First Results

Valtavirta, V., Hessan, M. & Leppänen, J., 2016, PHYSOR 2016: Unifying Theory and Experiments in the 21st Century. American Nuclear Society (ANS)

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

25 Citations (Scopus)

Expanding the Use of Serpent 2 to Fusion Applications: Shut-down Dose Rate Calculations

Leppänen, J. & Kaltiaisenaho, T., 2016, Proceedings of PHYSOR 2016: Unifying theory and experiments in the 21st century. American Nuclear Society (ANS)

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

12 Citations (Scopus)

Expanding the use of Serpent 2 to Fusion Applications: Development of a Plasma Neutron Source

Sirén, P. & Leppänen, J., 2016, PHYSOR 2016: Unifying Theory and Experiments in the 21st Century. American Nuclear Society (ANS)

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

5 Citations (Scopus)

Neutronic Assessment of TRISO Particle Fuels in a Small Fluoride Salt-cooled High-temperature Reactor

Mohamed, H., Lindley, B., Parks, G. & Leppänen, J., 2016, Proceedings of PHYSOR 2016: Unifying theory and experiments in the 21st century. American Nuclear Society (ANS)

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

New Interpolation Capabilities for Thermal Scattering Data in Serpent 2

Viitanen, T. & Leppänen, J., 2016, PHYSOR 2016: Unifying Theory and Experiments in the 21st Century. cd-rom ed. American Nuclear Society (ANS)

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

10 Citations (Scopus)

2015

Analyzing the statistics of group constants generated by Serpent 2 Monte Carlo code

Kaltiaisenaho, T. & Leppänen, J., 2015, Proceedings of the International Conference on the Physics of Reactors: PHYSOR 2014. Suyama, K., Sugawara, T., Tada, K., Chiba, G. & Yamamoto, A. (eds.). Vol. JAEA-Conf 2014-003. 9 p. 1106126

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

CAD-based geometry type in serpent 2-application in fusion neutronics

Leppänen, J., 2015, Mathematics and Computations, Supercomputing in Nuclear Applications and Monte Carlo International Conference . Curran Associates Inc., p. 1635-1646

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

11 Citations (Scopus)

Development of an unstructured mesh based geometry model in the Serpent 2 Monte Carlo code

Leppänen, J. & Aufiero, M., 2015, Proceedings of the international conference on physics of reactors: PHYSOR2014. Vol. JAEA-Conf 2014-003. 10 p. 1101586

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

Multiphysics simulation of fast transients with the FINIX fuel behaviour module

Ikonen, T., Syrjälahti, E., Valtavirta, V., Loukusa, H., Leppänen, J. & Tulkki, V., 2015, TopFuel 2015 Conference Proceedings. European Nuclear Society (ENS), Vol. I. p. 572-581

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

Open Access

Multiphysics simulations of fast transients in VVER-1000 and VVER-440 reactors

Syrjälahti, E., Valtavirta, V., Kättö, J., Loukusa, H., Ikonen, T., Leppänen, J. & Tulkki, V., 2015, Proceedings of the 11th International Conference on WWER Fuel Performance, Modeling and Experimental Support. Manolova, M., Boneva, S. & Mitev, M. (eds.). Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Science, p. 376-384 (WWER Fuel Performance, Modelling and Experimental Support; No. 2493).

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

Open Access

Simulating fast transients with fuel behavior feedback with the Serpent 2 Monte Carlo Code

Valtavirta, V., Ikonen, T., Viitanen, T. & Leppänen, J., 2015, Proceedings of the international conference on physics of reactors: PHYSOR2014. Vol. JAEA-Conf 2014-003. 12 p. 1105897

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

Target motion sampling temperature treatment technique with track-length estimators in OpenMC - preliminary results

Viitanen, T., Leppänen, J. & Forget, B., 2015, Proceedings of the international conference on physics of reactors: PHYSOR 2014. Vol. JAEA-Conf 2014-003. 11 p. 1106078

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

Unstructured mesh based multi-physics interface for CFD code coupling in the Serpent 2 Monte Carlo code

Leppänen, J., Valtavirta, V., Viitanen, T. & Aufiero, M., 2015, Proceedings of the international conference on physics of reactors: PHYSOR2014. Vol. JAEA-Conf 2014-003. 10 p. 1103981

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

2014

Analysing the statistics of group constants generated by serpent 2 monte carlo code

Kaltiaisenaho, T. & Leppänen, J., 2014, Proceedings of the International Conference on Physics of Reactors, PHYSOR 2014.

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

6 Citations (Scopus)

Development of a CAD based geometry model in serpent 2 Monte Carlo code

Leppänen, J., 2014, ANS Winter Meeting and Nuclear Technology Expo, 2014. American Nuclear Society (ANS), p. 663-667 (Transactions of the American Nuclear Society, Vol. 111).

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

4 Citations (Scopus)

2013

Comparison of serpent and HELIOS-2 as applied for the PWR few-group cross section generation

Fridman, E., Leppänen, J. & Wemple, C., 2013, International Conference on Mathematics and Computational Methods Applied to Nuclear Science and Engineering, M&C 2013. American Nuclear Society (ANS), p. 693-703

Research output: Chapter in Book/Report/Conference proceeding › Conference article in proceedings › Scientific › peer-review

14 Citations (Scopus)

Jaakko Leppänen

Research output

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