Monitoring and Leak testig of wwer-440 fuel assemblies in Slovak wet interim spent fuel storage facility

An accelerated monitoring system designed for the Slovak wet interim spent fuel storage facility in NPP Jaslovské Bohunice bases on the newly designed “cesium detectors” is presented in the paper. Since 1999, leak tests of WWER-440 fuel assemblies are provided by a special leak tightness detection system “Sipping in Pool” delivered by the Framatome-anp with external heating for the precise defects determination. Although this system seems to be very effective, the detection time of all fuel assemblies in one storage pool is too long. Therefore, a new “on-line” detection system, based on the new sorbent NIFSIL for an effective 134Cs and 137Cs activity was developed. The design of this detection system and its application possibility in Slovak wet interim spent fuel storage facility as well as preliminary results are presented

Criticality Safety Analysis of Spent Fuel Storage Pool for NPP Mochovce using MCNP5 Code

The paper presents results of nuclear criticality safety analysis of spent fuel storage and handling for the 1st and 2nd unit of NPP Mochovce. Spent fuel storage pool (compact and reserve grid) and T-12 transport cask were modeled using the Monte Carlo code MCNP5. Conservative approach was applied and calculation of max eff k values was performed for normal and various postulated emergency conditions in order to evaluate the final maximal max eff k values. The requirement of current safety regulations to ensure 5% subcriticality was met except some especially conservative cases

Criticality Safety Analysis of Spent Fuel Storage Pool for NPP Mochovce using MCNP5 Code

The paper presents results of nuclear criticality safety analysis of spent fuel storage and handling for the 1st and 2nd unit of NPP Mochovce. Spent fuel storage pool (compact and reserve grid) and T-12 transport cask were modeled using the Monte Carlo code MCNP5. Conservative approach was applied and calculation of max eff k values was performed for normal and various postulated emergency conditions in order to evaluate the final maximal max eff k values. The requirement of current safety regulations to ensure 5% subcriticality was met except some especially conservative cases

Analysis of Steam Generators Corrosion Products from Slovak NPP Bohunice

One of the main goals of the nuclear industry is to increase the nuclear safety and reliability of nuclear power plants (NPPs). As the steam generator (SG) is the most corrosion sensitive component of NPPs, it is important to analyze the corrosion process and optimize its construction materials to avoid damages like corrosion cracking. For this purpose two different kinds of SGs and its feed water distributing systems from the NPP Jaslovske Bohunice were studied by nondestructive Mössbauer spectroscopy. The samples were scraped from the surface and analyzed in transmission geometry. Magnetite and hematite were found to be the main components in the corrosion layers of both SGs. Dependant of the material the SG consisted of, and the location in the system where the samples were taken, the ratios between magnetite and hematite and the paramagnetic components were different. The obtained results can be used to improve corrosion safety of the VVER-440 secondary circuit as well as to optimize its water chemistry regime