Rami Pohja

20032019
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Research Output 2003 2019

2019

Assessing resilience in the energy supply sector

Tuurna, S., Auerkari, P., Molarius, R., Pohja, R., Jovanovic, A., Koivisto, R. & Hapuli, H., May 2019.

Research output: Contribution to conferenceConference AbstractProfessional

infrastructure
weather
freezing
power plant
probe
2018
5 Downloads (Pure)

Experimentally verified model based predictions for integrity of copper overpack: Annual report 2017

Rantala, J., Pohja, R. & Auerkari, P., 23 Mar 2018, Espoo: VTT Technical Research Centre of Finland. 17 p. (VTT Research Report; No. VTT-R-01499-18).

Research output: Book/ReportReport

Open Access
File
Creep
Creep testing
Copper
Testing
Metallography

Flexible future of power plants - challenges and solutions

Tuurna, S., Auerkari, P., Pohja, R., McNiven, U., Lilja, M. & Rydl, O., 13 Mar 2018.

Research output: Contribution to conferenceConference articleProfessional

Power plants
Plant shutdowns
Fouling
Feedstocks
Biomass

Practical aspects of applying risk-based approaches in asset management for heat exhangers

Tuurna, S., Auerkari, P., Pohja, R., Jovanovic, A. & Husta, S., 29 May 2018.

Research output: Contribution to conferenceOther conference contributionProfessional

life cycle
inspection
loss
statistics
distribution

Risk and resilience assessment for an energy supply system

Pohja, R., Auerkari, P., Tuurna, S., Hapuli, H. & Jovanovic, A., 19 Jun 2018. 7 p.

Research output: Contribution to conferenceConference AbstractScientificpeer-review

infrastructure
heating
cooling
weather
city

Risk and resilience assessment for an urban system of energy supply

Molarius, R., Auerkari, P., Koivisto, R., Tuurna, S., Pohja, R., Jovanovic, A. & Hapuli, H., 30 Oct 2018. 13 p.

Research output: Contribution to conferenceConference articleProfessional

urban system
infrastructure
energy supply
2017

Creep modelling for long-term low strain regime including the limit of negligible creep

Auerkari, P., Holmström, S., Pohja, R. & Rantala, J., 2017. 6 p.

Research output: Contribution to conferenceConference articleScientificpeer-review

Creep
Welding
Availability
Steel
Testing

Determination of high temperature material properties of 15-15Ti steel by small specimen techniques

Holmström, S., Simonovski, I., de Haan, F., Lapetite, J-M., Balardi, D., Serrano, M., Altstadt, E., Aktaa, J., Radu, V., Namburi, H., Cristalli, C., Pohja, R., Delville, R. & Courcelle, A., 2017, European Union. 118 p. (EU Publications, Vol. EUR 28746 EN).

Research output: Book/ReportReport

Open Access
Materials properties
Tensile strength
Steel
Anisotropy
Tensile properties
2 Citations (Scopus)

Engineering models for softening and relaxation of Gr. 91 steel in creep-fatigue conditions

Holmström, S., De Haan, F., Föhrer, U., Pohja, R. & Janousek, J., 1 Jan 2017, In : International Journal of Structural Integrity. 8, 6, p. 670-682 13 p.

Research output: Contribution to journalArticleScientificpeer-review

Open Access
Creep
Fatigue of materials
Steel
Fatigue damage
Hardening

Lämmönvaihtimen RBI

Auerkari, P., Pohja, R., Tuurna, S. & Tuhti, A., 2017, VTT Technical Research Centre of Finland. (VTT Tutkimusraportti; No. VTT-R-04939-16).

Research output: Book/ReportReport

Physics and chemistry of nuclear fuel (PANCHO)

Arkoma, A., Ikonen, T., Kättö, J., Loukusa, H., Myllykylä, E., Pohja, R., Tulkki, V. & Valtavirta, V., 2017, SAFIR2018 - The Finnish Research Programme on Nuclear Power Plant Safety 2015-2018: Interim Report. VTT Technical Research Centre of Finland, p. 192-202 (VTT Technology, Vol. 294).

Research output: Chapter in Book/Report/Conference proceedingChapter or book articleProfessional

Open Access

Practical aspects of applying risk-based approaches in asset management for power plant

Auerkari, P., Jovanovic, A., Husta, S., Pohja, R., Tuurna, S., Pohjanne, P., McNiven, U. & Laaksonen, L., 2017. 10 p.

Research output: Contribution to conferenceConference articleScientific

power plant
life cycle
inspection
spatial distribution
loss

Predicted life of P91 steel for cyclic high temperature service

Pohja, R., Holmström, S., Auerkari, P. & Nurmela, A., 2 Nov 2017, In : Materials at High Temperatures. 34, 5-6, p. 301-310 10 p.

Research output: Contribution to journalArticleScientificpeer-review

Steel
Creep
steels
stress corrosion cracking
power plants

Predicted life of thick-wall P91 steel for cyclic high temperature service

Pohja, R., Holmström, S., Auerkari, P. & Nurmela, A., 2017.

Research output: Contribution to conferenceConference articleScientificpeer-review

Creep
Steel
Steam
Temperature
Martensitic steel

Report on an experimental campaign on cladding transient behaviour

Pohja, R. & Huotilainen, S., 2017, VTT Technical Research Centre of Finland. (VTT Research Report, Vol. VTT-R-00799-17).

Research output: Book/ReportReport

Creep
Zirconium
Zirconium alloys
Nuclear fuels
Recovery

Report on challenges for SCIs

Walther, G., Jovanovic, M., Vollmer, M., Desmond, G., Choudhary, A., Auerkari, P., Tuurna, S., Pohja, R., Koivisto, R., Molarius, R. & et al., 2017, European Commission EC. 85 p. (Smart Resilience Indicators for Smart Critical Infrastructures).

Research output: Book/ReportReport

Open Access
Industry
Decision making

Supervised RIsx: Defining resilience indicators based on risk assessment

Øien, K., Bodsberg, L., Hoem, Å., Øren, T., Molarius, R., Koivisto, R., Auerkari, P., Pohja, R., Tuurna, S. & et al., 2017, European Commission EC. 280 p. (Smart Resilience Indicators for Smart Critical Infrastructures).

Research output: Book/ReportReport

risk assessment
infrastructure
monitoring
crisis management
indicator

Test methodologies for determining high temperature material properties of thin walled tubes

Holmström, S., Bruchhausen, M., Nilsson, K-F., Pohja, R., Altstadt, E., Serrano, M., Radu, V., Cristalli, C., Aktaa, J., Namburi, H., Delville, R. & Courcelle, A., 2017, Luxembourg: European Union. 33 p. (EU Publications, Vol. EUR 28642 EN).

Research output: Book/ReportReport

Open Access
Materials properties
Tensile testing
Nuclear fuel cladding
Testing
Temperature

Uncertainties, decision criteria and resilience to damage and failure of a heat exchanger

Auerkari, P., Pohja, R., Tuurna, S., Tuhti, A., Laaksonen, L. & McNiven, U., 2017.

Research output: Contribution to conferenceConference AbstractScientific

Heat exchangers
Inspection
Feedwater heaters
Plant shutdowns
Maintainability
2016

Creep performance of fuel cladding

Pohja, R., Tulkki, V., Ikonen, T., Moilanen, P., Rantala, J., Huotilainen, S. & Ehrnstén, U., 2016, Baltica X: International Conference on Life Management and Maintenance for Power Plants. Auerkari, P. (ed.). Espoo: VTT Technical Research Centre of Finland, 8 p. (VTT Technology, Vol. 261).

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

Open Access
Creep
Zirconium alloys
Nuclear fuel cladding
Nuclear reactors
Austenitic stainless steel

Joustavan käytön haasteita korkean lämpötilan rakenteille

Pohja, R., 2016.

Research output: Contribution to conferenceConference articleProfessional

Lifetime assessment: Modelling of steamside oxidation

Yli-Olli, S., Auerkari, P., Tuurna, S., Pohja, R. & Holmström, S., 2016, Baltica X: International Conference on Life Management and Maintenance for Power Plants. Auerkari, P. (ed.). Espoo: VTT Technical Research Centre of Finland, 8 p. (VTT Technology, Vol. 261).

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

Open Access
Oxidation
Oxidation resistance
Alloying elements
Steam
Chemical analysis

Multiaxial creep testing device for nuclear fuel claddings

Pohja, R., Moilanen, P., Rantala, J., Huotilainen, S., Tulkki, V., Ehrnstén, U. & Holmström, S., 2016, In : Athens Journal of Sciences. 3, 3, p. 227-240

Research output: Contribution to journalArticleScientificpeer-review

Open Access
Nuclear fuel cladding
Creep testing
Creep
Pneumatics
Nuclear reactors

Performance of high-temperature materials for efficient power plants: The waterside challenge

Auerkari, P., Yli-Olli, S., Penttilä, S., Tuurna, S. & Pohja, R., 1 Jul 2016, In : Journal of Nuclear Engineering and Radiation Science. 2, 3, 031009.

Research output: Contribution to journalArticleScientificpeer-review

refractory materials
power plants
Power plants
oxidation
turbogenerators

RBI and assessment of component life for high temperature service

Auerkari, P., Pohja, R., Yli-Olli, S., Tuurna, S., Pohjanne, P., McNiven, U. & Husta, S., 2016.

Research output: Contribution to conferenceConference articleScientific

Inspection
Temperature
Cogeneration plants
Standardization
Deterioration

Relaxation behaviour of copper in disposal canisters

Rantala, J., Pohja, R., Auerkari, P., Laukkanen, A. & Andersson, T., 2016, Baltica X: International Conference on Life Management and Maintenance for Power Plants. Auerkari, P. (ed.). Espoo: VTT Technical Research Centre of Finland, 8 p. (VTT Technology, Vol. 261).

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

Open Access
cans
disposal
copper
creep analysis
waste disposal

Supercritical water oxidation and creep behaviour of boiler tube materials

Tuurna, S., Yli-Olli, S., Pohja, R. & Penttilä, S., 2016, Proceedings of 8th International Conference on Advances in Materials Technology for Fossil Power Plants. ASM International, p. 924-930

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

Boilers
Creep
Ashes
Oxidation
Water
2015

Creep-fatigue design of Gen IV high temperature reactor plants

Pohja, R., 2015, Materials Science and Technology - Nuclear Materials, Advanced Course. Hänninen, H. & Kiesi, T. (eds.). Helsinki: Aalto University, p. 65-77 (Aalto University Publication Series Science + Technology; No. 16/2015).

Research output: Chapter in Book/Report/Conference proceedingChapter or book articleProfessional

Open Access
High temperature reactors
Creep
Fatigue of materials
Fatigue damage
Microstructural evolution

Cyclic softening of tempered ferritic-martensitic steel P91

Janousek, J., Holmström, S. & Pohja, R., 2015.

Research output: Contribution to conferenceConference articleScientific

Martensitic steel
Ferritic steel
Creep testing
Viscoplasticity
Fatigue testing

Performance of high temperature materials for efficient power plant: the water side challenge

Auerkari, P., Yli-Olli, S., Penttilä, S., Tuurna, S. & Pohja, R., 2015, Proceedings of the 7th International Symposium on Supercritical Water-Cooled Reactors (ISSCWR 2015). USB stick ed. VTT Technical Research Centre of Finland, 8 p. 2099. (VTT Technology; No. 216).

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientific

Open Access
Power plants
Oxidation resistance
Water
Bearings (structural)
Temperature

RBI and probabilistic life assessment for components of coal and co-fired power plants

Auerkari, P., Pohja, R., Yli-Olli, S., Tuurna, S., Pohjanne, P. & McNiven, U., 2015, Proceedings of the 41st MPA-Seminar. Materials Testing Institute University of Stuttgart MPA, 11 p.

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientific

Power plants
Inspection
Coal
Standardization
Chemical industry

Recommendation for creep and creep-fatigue assessment for P91 components

Pohja, R., Holmström, S. & Lee, H-Y., 2015, 43 p.

Research output: Book/ReportReport

Open Access
Creep
Fatigue of materials
Steel

Riskiperustaisesta arvioinnista tukea voimalaitoskomponenttien eliniän hallintaan

Tuurna, S., Pohja, R. & Auerkari, P., 2015, In : Voima ja käyttö. 109, 10, 17.

Research output: Contribution to journalArticleProfessional

State-of-the-art review of data on fuel cladding interaction in advanced fuels for Gen IV reactors

Dumas, J-C., Martinelli, L., Bottomley, D., Wallenius, J., Tulkki, V. & Pohja, R., 2015, European Commission EC. 91 p.

Research output: Book/ReportReport

Constitutive models
Nitrides
Piles
Data structures

Synthesis of the experimental work for the design rules improvement

Bernardi, D., Aktaa, J., Blat-Yrieix, M., Bruchhausen, M., Cristalli, C., Dolci, F., Holmström, S., Lee, H-Y., Matheron, P., Nilsson, K-F., Pohja, R., Vincent, W. & Zhang, K., 2015, 153 p.

Research output: Book/ReportReport

Creep
Fatigue of materials
Martensitic steel
Ferritic steel
Austenitic stainless steel
9 Citations (Scopus)

Synthesis of the recommendations

Aiello, G., Aktaa, J., Ancelet, O., Angiolini, M., Barbieri, G., Blat Yrieix, M., Dubiez-Le Goff, S., Dundulis, G., Forest, L., Giannuzzi, G., Grybenas, A., Holmström, S., Jia Chao, C., Lebarbé, T., Lee, H-Y., Matheron, P., Nilsson, K-F., Pohja, R., Schroer, C., Smith, G. & 2 others, Testani, C. & Zhang, K., 2015, European Commission EC.

Research output: Book/ReportReport

Uncertainty
2014

A comparison of creep-fatique assessment and modelling methods

Pohja, R. & Holmström, S., 2014, Proceedings of the 22th International Conference on Nuclear Engineering, ICONE22: Volume 1: Plant Operations, Maintenance, Engineering, Modifications, Life Cycle and Balance of Plant; Nuclear Fuel and Materials; Plant Systems, Structures and Components; Codes, Standards, Licensing and Regulatory Issues. American Society of Mechanical Engineers ASME, 10 p.

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

Creep
Fatigue of materials
Fatigue damage
Martensitic steel
Safety factor

A study of creep-fatigue interaction in the nickel-base superalloy 263

Pohja, R., Holmström, S., Nurmela, A. & Moilanen, P., 2014, Proceeding CD: 10th Liege Conference on Materials for Advanced Power Engineering 2014. p. 678-687

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

Superalloys
Creep
Nickel
Fatigue of materials
Fatigue damage
3 Citations (Scopus)

Creep-fatigue interaction models for grade 91 steel

Holmström, S., Pohja, R. & Payten, W., 2014, In : Materials Performance and Characterization. 3, 2, p. 156-181 25 p., MPC20130054.

Research output: Contribution to journalArticleScientificpeer-review

Steel
Creep
Fatigue of materials
Ductility
Strain energy

Creep-fatigue interaction rules for P91: MATTER – Deliverable D4.5

Pohja, R., Holmström, S., Nilsson, K-F., Payten, W., Lee, H-Y. & Aktaa, J., 2014, Rome, Italy. 64 p.

Research output: Book/ReportReport

Creep
Fatigue of materials
Ductility
Fatigue damage
Heat exchangers

Fiscal year report (9/2013 - 9/2014) of the Academy of Finland project IDEA (Interactive Modelling of Fuel Cladding Degradation Mechanisms)

Anderson, T., Huotilainen, S., Loukusa, H., Penttilä, S., Pohja, R. & Tulkki, V., 2014, VTT Technical Research Centre of Finland. 10 p. (Helsinki University of Technology: Systems Analysis Laboratory. A: Research Reports; No. VTT-R-05121-14).

Research output: Book/ReportReport

Lifing of high temperature plant: deterministic and probabilistic methods

Auerkari, P., Pohja, R., Yli-Olli, S., Rantala, J. & Laukkanen, A., 2014, VTT Technical Research Centre of Finland. 21 p. (VTT Research Report; No. VTT-R-00753-14).

Research output: Book/ReportReport

power plant
damage
method
temperature
trend

Relaxation of OFP copper

Auerkari, P., Pohja, R., Nurmela, A. & Rantala, J., 2014, Espoo: VTT Technical Research Centre of Finland. 12 p. (VTT Research Report; No. VTT-R-00366-14).

Research output: Book/ReportReport

phosphorus
cans
copper
oxygen
spent fuels
Stress relaxation
Sensitivity analysis
Creep
Copper
Phosphorus
2013

Corrosion resistance of Kanthal A-1 and Fe-12Cr-2Si alloy coatings in Cl-containing environment

Sarikka, T., Ilola, R., Pohja, R. & Hänninen, H., 2013, Baltica IX. International Conference on Life Management and Maintenance for Power Plants. Auerkari, P. & Veivo, J. (eds.). Espoo: VTT Technical Research Centre of Finland, p. 500-512 (VTT Technology; No. 106).

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

Open Access
Corrosion resistance
Coatings
Aluminum Oxide
Stainless Steel
Corrosion

Corrosion resistance of Kanthal A-1 and Fe-12Cr-2Si alloy coatings in Cl-containing environment

Sarikka, T., Ilola, R., Pohja, R. & Hänninen, H., 2013, Baltica IX. International Conference on Life Management and Maintenance for Power Plants - Abstracts. Auerkari, P. & Veivo, J. (eds.). Espoo: VTT Technical Research Centre of Finland, p. 74 (VTT Technology; No. 107).

Research output: Chapter in Book/Report/Conference proceedingConference abstract in proceedingsScientific

Open Access
Corrosion resistance
Coatings
Aluminum Oxide
Stainless Steel
Corrosion
9 Citations (Scopus)

Creep and creep-fatigue behaviour of 316 stainless steel

Holmström, S., Pohja, R., Nurmela, A., Moilanen, P. & Auerkari, P., 2013, In : Procedia Engineering. 55, p. 160-164 5 p.

Research output: Contribution to journalArticleScientificpeer-review

Open Access
Creep
Stainless steel
Fatigue of materials
High temperature properties
Steel