Fuel cycles with PK-3+ FAs for VVER-440 reactors
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P. Mikoláš
Abstract
In order to increase the efficiency of fuel utilization at Dukovany NPP, the design of FA was changed by shroud removal and replacement with a structure called “Karkas”. Optimization of PK-3+ type FAs with different average enrichments was performed in order to find out those enrichment profiles with minimized non-uniform energy generation in FA (during burn-up). In addition, it was assumed that such a radial enrichment profile in FA could be achieved by making a change in the location of the fuel pin with a Gd2O3 burnable absorber – from the 2nd row to the 3rd row of pins from the edge of the fuel assembly on the fuel assembly diagonal. The aim of this study was to achieve a full quadruplicate cycle, every 15 months (approx. 450 days) at 1475 MWt nominal power. Preliminary results indicate that combination of PK-3+ and Gd-2M+ fuel assemblies does not show any unusual phenomena from the point of view of reactor physics. The proposed strategy is based on B1C33 cycle implemented at Dukovany NPP that is designed to be 395 FPDs. Already in the first “transient” cycle (34th) loaded with 60 fresh PK-3+ FAs and 12 Gd-2M++ CAs, the reached length at EOR is 424 FPDs, which means stretch-out 26 effective days. Averaged, the transition cycle stretch-out length is 23.5 effective days. For steady cycles, this average value is 19.2 effective days.
Kurzfassung
Um die Effizienz der Brennstoffausnutzung im Kernkraftwerk Dukovany zu erhöhen, wurde das Design der FA durch Entfernen der Hülle und Ersetzen durch eine Struktur namens „Karkas“ geändert. Es wurde eine Optimierung der PK-3+ Typ Brennelemente mit unterschiedlichen durchschnittlichen Anreicherungen durchgeführt, um jene Anreicherungsprofile mit minimierter ungleichmäßiger Energieerzeugung in FA (beim Abbrand) herauszufinden. Darüber hinaus wurde angenommen, dass ein solches radiales Anreicherungsprofil in Brennelementen durch eine Änderung des Ortes des Absorberstabs mit dem abbrennbaren Gd2O3 erreicht werden kann – von der zweiten Reihe in die dritte Reihe der Brennstäbe vom Rand des Brennelements auf der Brennelementdiagonalen aus gesehen. Ziel dieser Studie war es, alle 15 Monate (ca. 450 Tage) bei 1475 MWt Nennleistung einen vollständigen Vierfachzyklus zu erreichen. Vorläufige Ergebnisse deuten darauf hin, dass die Kombination von PK-3+- und Gd-2M+-Brennelementen keine ungewöhnlichen Phänomene aus reaktorphysikalischer Sicht zeigt. Die vorgeschlagene Strategie basiert auf dem B1C33-Zyklus, der im KKW Dukovany implementiert wurde und auf 395 FPDs ausgelegt ist. Bereits im ersten „transienten“ Zyklus (34.), der mit 60 frischen PK-3+ FAs und 12 Gd-2M++ CAs beladen ist, beträgt die erreichte Zykluslänge 424 FPDs, was einer Verlängerung von 26 effektiven Tagen entspricht. Im Durchschnitt beträgt die Strecklänge des Übergangszyklus 23,5 effektive Tage. Für Gleichgewichtszyklen beträgt dieser Durchschnittswert 19,2 effektive Tage.
References
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© 2019, Carl Hanser Verlag, München
Artikel in diesem Heft
- Contents/Inhalt
- Contents
- Editorial
- Research on the reactor physics and reactor safety of VVER reactors – AER Symposium 2018
- Technical Contributions/Fachbeiträge
- Development of CASMO5 for VVER-1000/1200 analysis and preliminary validation using critical experiments
- C-PORCA 7: a nodal diffusion reactor calculation code to support off-line and on-line core analysis at Paks nuclear power plant
- Adaptation of the gas gap simplified model in DYN3D code to new types of fuel
- A procedure for verification of Studsvik's spent nuclear fuel code SNF
- Extension of nodal diffusion solver of Ants to hexagonal geometry
- VVER-1000 fuel assembly model in CAD-based unstructured mesh for MCNP6
- Fuel cycles with PK-3+ FAs for VVER-440 reactors
- Prospects for implementation of VVER nuclear fuel enriched above 5%
- Core loading optimisation in Slovak VVER-440 reactors
- Statistical evaluation of C-15 cycles in Paks NPP, based on measured in-core data
- Optimized 18-months low-leakage core loadings for uprated VVER-1000
- Leningrad NPP-2 start-up loss of power test and its simulation with use of KORSAR/GP code
- Assessment of the fuel assembly pin-by-pin model in the KORSAR/GP code
- Comparative thermohydraulic analyses of VVER 1000 active core for two different construction types of assemblies
- Analysis of uncontrolled dilution of boric acid concentration in the reactor VVER-1000/320
- Applied study on optimizing the final disposal of Loviisa NPP spent fuel assemblies
- Criticality safety analysis for GNS IQ® – The Integrated Quiver System for damaged fuel
- Neutron balance in two-component nuclear energy system
Artikel in diesem Heft
- Contents/Inhalt
- Contents
- Editorial
- Research on the reactor physics and reactor safety of VVER reactors – AER Symposium 2018
- Technical Contributions/Fachbeiträge
- Development of CASMO5 for VVER-1000/1200 analysis and preliminary validation using critical experiments
- C-PORCA 7: a nodal diffusion reactor calculation code to support off-line and on-line core analysis at Paks nuclear power plant
- Adaptation of the gas gap simplified model in DYN3D code to new types of fuel
- A procedure for verification of Studsvik's spent nuclear fuel code SNF
- Extension of nodal diffusion solver of Ants to hexagonal geometry
- VVER-1000 fuel assembly model in CAD-based unstructured mesh for MCNP6
- Fuel cycles with PK-3+ FAs for VVER-440 reactors
- Prospects for implementation of VVER nuclear fuel enriched above 5%
- Core loading optimisation in Slovak VVER-440 reactors
- Statistical evaluation of C-15 cycles in Paks NPP, based on measured in-core data
- Optimized 18-months low-leakage core loadings for uprated VVER-1000
- Leningrad NPP-2 start-up loss of power test and its simulation with use of KORSAR/GP code
- Assessment of the fuel assembly pin-by-pin model in the KORSAR/GP code
- Comparative thermohydraulic analyses of VVER 1000 active core for two different construction types of assemblies
- Analysis of uncontrolled dilution of boric acid concentration in the reactor VVER-1000/320
- Applied study on optimizing the final disposal of Loviisa NPP spent fuel assemblies
- Criticality safety analysis for GNS IQ® – The Integrated Quiver System for damaged fuel
- Neutron balance in two-component nuclear energy system
