Effective Dose Calculation in the VVER-440 Maintenance Area

Osuský, F.; Nečas, Vladimı́r; Vrban, Branislav

doi:10.13182/t123-33336

Cited by 2 publications

(7 citation statements)

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“…It consists of the reactor invessel components, such as fuel assemblies (including fuel rods, upper spacer grid, intermediate spacer grids, supporting grid, mixing grid, central tube and fuel endings), emergency reactor control assemblies (ERCabsorber and fuel part), core basket, barrel and the reactor pressure vessel. The boundaries of the created VVER-440 whole-core model are given by the outer surface of the dry shielding, the level of hot-leg piping and the basement of filtration mechanism [3].…”

Section: A the Vver-440 Reactor Corementioning

confidence: 99%

“…The fuel rods are located in the bundle in a triangular grid pattern with 12.3 mm pitch. The fuel rod cladding is made from E110 zirconium alloy, while the wrapper tubes of FA and ERC are made from E125 zirconium alloy [3]. As it was mentioned in the introduction part, the analysis presented in this paper was carried out for the first fuel loading of Mochovce unit 3, considering a simplified approach.…”

Section: A the Vver-440 Reactor Corementioning

confidence: 99%

“…The dilution is performed by pumping out a certain amount of moderator and replacing it with demineralized H2O. As the boric acid is diluted the concentration of 10 B and 11 B atoms decreases, however the concentrations of 16 In order to use these concentrations in the estimation of 3 H inventory, the concentrations should be substituted by simple functions that accurately represent the number density of the sought atoms at the given time step. Since the functions of concentrations of 1 H, 2 H and 10 B, 11 B atoms are relatively complex the fuel cycle (0 -266.95 EFPD) has been divided to 9 intervals while a simple exponential fit was used for each interval.…”

Section: Dilution Of Boric Acidmentioning

confidence: 99%

“…The light-water coolant as passes through the reactor core, to remove the generated heat from fuel assemblies, gets activated by capturing moderated neutrons. During normal operation numerous neutron induced reactions take place, generating a variety of radioactive nuclides, such as 16 N, 17 N, 14 C or 3 H. Due to the relatively long halflife of the majority of these activation products, their concentration in the primary coolant directly influences the radiation exposure of personnel performing maintenance activities. Among all radioactive nuclides produced during reactor operation tritium ( 3 H) is one of the most important.…”

Section: Introductionmentioning

confidence: 99%

“…The Slovak NPP Mochovce with VVER-440 V-213 units 1 and 2 were put in operation in the summer of 1998 and the end of year 1999 due to the construction delay caused by political changes in the early 1990s. Two another units 3&4 of VVER-440 V-213 are currently under construction in Mochovce and are planned to be put in operation in 2020 [3]. Since the operation of the Jaslovské Bohunice V2 NPP and the first two units of Mochovce NPP started decades ago, estimation of the tritium inventory through calculation would be a very challenging issue.…”

Section: Introductionmentioning

confidence: 99%

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Estimation of Tritium Production in VVER-440 Reactor Core During Normal Operation

Čerba

Lüley²,

Vrban³

et al. 2019

Nucl. Sci. and Tech.

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Slovakia as one of the world leading countries in the share of nuclear power in electricityproduction and currently operates 2 nuclear power plants, each with 2 VVER-440 units. In addition to these reactors there are 2 VVER-440 units under construction and 2 units in decommissioning. The VVER-440 technology features thermal neutron spectrum, low enriched uranium dioxide fuel and light-water coolant, diluted boric acid and 37 emergency reactivity control assemblies with boron steel absorber. Due to the presence of 10B in the coolant/moderator which has high thermal neutron capture cross-section, the absorption of neutron on these atoms may lead to tritium production. Tritiumstrongly contributes to the level of radioactivity of the primary coolant, therefore the NPP staff must have appropriate knowledge of its production during operation. This paper focuses on the estimation of the tritium production for a specific scenario of the operation of the 3rd unit of Mochovce NPP. For simulations the SCALE6 system is used with the detailed calculation model developed at the B&J NUCLEAR ltd. company. The calculations presented in the paper are performed using self-shielded multi-group cross-section libraries, taking into account the operation conditions of Mochovce unit 3 NPP in the first fuel campaign.

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Section: A the Vver-440 Reactor Corementioning

confidence: 99%

Section: A the Vver-440 Reactor Corementioning

confidence: 99%

Section: Dilution Of Boric Acidmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Estimation of Tritium Production in VVER-440 Reactor Core During Normal Operation

Čerba

Lüley²,

Vrban³

et al. 2019

Nucl. Sci. and Tech.

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Printed circuit heat exchangers and fast neutron radiography

Vrban

Čerba

Lüley

et al. 2023

Eur. Phys. J. Spec. Top.

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Non-destructive testing is capable of detecting defects of important components, where a failure could pose a significant hazard and cause severe economic losses. Currently, imaging techniques utilizing gamma or X-ray sources are mainly used and allow to examine of devices ranging in size from units to tens of centimetres, but for industrial-sized large components, these methods usually fail. The utilization of fast neutrons in radiography is a promising alternative, especially for industrial applications. Currently, due to the higher neutron-matter interaction probabilities, most neutron-imaging systems use thermal neutrons originating from research reactors. Due to the intention of on-site inspection of revealing the possible ruptures and failures, this option is not applicable. The paper presents the newly developed neutronic models of printed circuit heat exchangers where the specific ruptures are defined. Next, neutron transport simulations are performed to investigate the different irradiation geometries, various neutron sources, and backfill materials to access the principal detectability of these ruptures in the industrial environment. Finally, conclusions are drawn, and the best backfill material and neutron source are identified in the simplified model.

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Effective Dose Calculation in the VVER-440 Maintenance Area

Cited by 2 publications

References 0 publications

Estimation of Tritium Production in VVER-440 Reactor Core During Normal Operation

Estimation of Tritium Production in VVER-440 Reactor Core During Normal Operation

Printed circuit heat exchangers and fast neutron radiography

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