The rod insertion method for control rod worth measurement is explained and past as well as recent developments are outlined. The original methodology is updated with a more consistent use of the flux redistribution correction, conversion from dynamic to static reactivity and a new procedure to account for the so-called reactivity overshoot. As an example, the procedure is applied to real measured data from Krško NPP. Resulting integral and differential worth curves are compared with reference measurements by the boron dilution method, where a previously unattainable match is observed. Additional research is presented in order to assess the remaining small deviations. Besides other advantages, the rod insertion method is demonstrated to produce results that are in excellent agreement with those of boron dilution method and can therefore be used as replacement
COBISS.SI-ID: 30971175
MCNP and the ADVANTG code were used to analyse dose rates for the future Slovenian LILW repository. Using ADVANTG as variance reduction technique, different detailed calculations of dose rates were achievable in a reasonable time, whereby the analogue MCNP simulations were accelerated up to 9500 times. We analysed the influence of different repository configurations on the annual dose rates up to 150 m from the outer edge of the repository. The results show that, for all configurations of the open repository where the waste from different sources is deposited, the calculated annualc-dose rates were lower than the prescribed limitation (20 mSv/year). By considering also the waste from the Krško NPP,which represents the major contribution by activity and volume, the dose rates increased 698 times.By applying a 33 cm thick layer of the filling grout, the calculated dose rates dropped below the limitation.
COBISS.SI-ID: 19179011
Validation and evaluation of the recently released ADVANTG code is presented in the paper. ADVANTG is a hybrid transport code, which combines a deterministic neutron transport code Denovo with MCNP, a well-known Monte Carlo (MC) transport code. ADVANTG was tested on an ICSBEP labyrinth benchmark where neutron fluxes were measured and calculated in a three-section concrete labyrinth for a 252Cf neutron source. The speed-up factors or the increases in relative efficiency of up to 1400 compared to analog MCNP simulations were achieved using the ADVANTG-generated variance reduction parameters. ADVANTG accelerated the calculations in terms of the CPU time and the calculated values were in good agreement with the experimental values. Additionally, it was shown that no bias was introduced by the ADVANTG code, as the mean values obtained by the ADVANTG accelerated calculation are within statistical uncertainties of the analog calculation. The presented work has shown that ADVANTG is a useful tool for use in solving neutron transport problems in geometries featuring labyrinth.
COBISS.SI-ID: 31058215
Validation and evaluation of the recently released ADVANTG code, which combines a well-known Monte Carlo (MC) transport code MCNP with a deterministic neutron transport code Denovo, is presented in the paper. The aim of ADVANTG is to automate the process of generating the variance reduction parameters for the fixed source MCNP calculations, which consequently accelerate the simulations in terms of the required CPU time. Reliability and consistent performance of the ADVANTG code were tested on a computationally demanding benchmark, i.e. the skyshine benchmark experiment from the ICSBEP handbook where neutron and photon scattering in the air above an open operating reactor are simulated. The speed-up factors or the increases in relative efficiency of up to 30,000 and 1400 compared to analog MCNP simulations were achieved using the ADVANTG-generated variance reduction parameters for neutrons and photons respectively. As the mean values obtained by the ADVANTG-accelerated simulation sit within the statistical uncertainties of the analog simulation, it was shown that no additional bias is introduced by the ADVANTG code. This article shows that ADVANTG code is a useful and effective tool for use in solving neutral particle transport problems in large geometries featuring skyshine
COBISS.SI-ID: 31878695