The paper presents the main features of the Sn calculation sequence SCALENEA-1 that has been extensively used for radioactive inventories, source terms, wastes and dose rates calculation for ITER, SEAFP and IFMIF fusion machines. The sequence includes the following steps: 1. nuclear data processing (from Evaluated Nuclear Data File), to produce master and working data libraries (problem dependent); 2. radiation (n, g) transport analysis, to produce neutron and gamma spectra; 3. radiation transport results post-processing, such as: a) radioactive inventories (activation calculations with activation code packages, e.g. the ANITA-2000), b) radiation damage, c) dose rates, and d) nuclear heating. As part of the validation process for the code package and for the calculation sequence, experimental-calculation comparison has been performed using the information and the measured isotope radioactive inventories and dose rate gathered from drum containers of a “low-level waste repository”. The study was developed through the following steps: a) collection and processing of measured data (radioactivity content and dose rate), from the cemented containers of the repository (data from 35 drums were analyzed); b) decay gamma source calculation by the ANITA-2000 code package (the input data for the calculations are the measured isotope activities for each container); c) decay gamma transport calculation by the Scalenea-1 shielding Sn sequence approach (Bonami-Nitawl-Xsdrnpm-Xsdose modules of the Scale 4.4a code system, using the Vitenea-J library, based on FENDL/E-2 data) to obtain dose rates on the surfaces and at various points outside the containers ; d) comparison experimental-calculated dose rates, taking into account also the measurement uncertainties. In order to guarantee a complete Quality Assurance for codes and calculation scheme, a simulation of the radioactive containers to evaluate the dose rates was done also by using the Monte Carlo MCNP-4c code. The following conclusions can be outlined from the result analysis: - Agreement with the (gamma dose rates) experimental data: discrepancies (C-E)/E lower than 50%. - Sn (Scalenea-1) and Monte Carlo (MCNP 4c) comparison: discrepancies lower than 1%. The analyses done provided a contribution to the Validation process of the ANITA-2000 activation code package and, more extensively, of the overall calculation sequence used to perform activation calculations for ITER GSSR. As a general conclusion, the Scalenea-1 calculation sequence is able to provide reliable results for various ITER safety analyses purposes.
The SCALENEA-1 multipurpose Sn calculation sequence for application in fusion field: main features and its validation based on experimental data from a low-level waste repository
CAMBI, GILIO;
2004
Abstract
The paper presents the main features of the Sn calculation sequence SCALENEA-1 that has been extensively used for radioactive inventories, source terms, wastes and dose rates calculation for ITER, SEAFP and IFMIF fusion machines. The sequence includes the following steps: 1. nuclear data processing (from Evaluated Nuclear Data File), to produce master and working data libraries (problem dependent); 2. radiation (n, g) transport analysis, to produce neutron and gamma spectra; 3. radiation transport results post-processing, such as: a) radioactive inventories (activation calculations with activation code packages, e.g. the ANITA-2000), b) radiation damage, c) dose rates, and d) nuclear heating. As part of the validation process for the code package and for the calculation sequence, experimental-calculation comparison has been performed using the information and the measured isotope radioactive inventories and dose rate gathered from drum containers of a “low-level waste repository”. The study was developed through the following steps: a) collection and processing of measured data (radioactivity content and dose rate), from the cemented containers of the repository (data from 35 drums were analyzed); b) decay gamma source calculation by the ANITA-2000 code package (the input data for the calculations are the measured isotope activities for each container); c) decay gamma transport calculation by the Scalenea-1 shielding Sn sequence approach (Bonami-Nitawl-Xsdrnpm-Xsdose modules of the Scale 4.4a code system, using the Vitenea-J library, based on FENDL/E-2 data) to obtain dose rates on the surfaces and at various points outside the containers ; d) comparison experimental-calculated dose rates, taking into account also the measurement uncertainties. In order to guarantee a complete Quality Assurance for codes and calculation scheme, a simulation of the radioactive containers to evaluate the dose rates was done also by using the Monte Carlo MCNP-4c code. The following conclusions can be outlined from the result analysis: - Agreement with the (gamma dose rates) experimental data: discrepancies (C-E)/E lower than 50%. - Sn (Scalenea-1) and Monte Carlo (MCNP 4c) comparison: discrepancies lower than 1%. The analyses done provided a contribution to the Validation process of the ANITA-2000 activation code package and, more extensively, of the overall calculation sequence used to perform activation calculations for ITER GSSR. As a general conclusion, the Scalenea-1 calculation sequence is able to provide reliable results for various ITER safety analyses purposes.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
