Corresponding author: Andrei A. Andrianov (
Academic editor: Yury Kazansky
The paper provides a brief description of the functionality of the nuclear energy system modelling application package (
Andrianov AA, Kuptsov IS, Osipova TA, Spiridonova AA, Andrianova ON, Utianskaya TV (2022) Nuclear energy system modelling application package: functional overview and examples. Nuclear Energy and Technology 8(4): 289–295.
Software tools for conducting technical and economic modelling of nuclear energy systems (
Such software tools are used for a comprehensive analysis and feasibility study of possible
The corresponding calculation tools integrate submodels of various levels: physical models that make it possible to assess changes in the nuclide composition and characteristics of nuclear fuel in reactors and in the different
Despite the existing arsenal of models, approaches, and software tools for systematic studies of the prospects for the development of nuclear energy, systematic work is currently underway on further upgrading and improving them in order to provide the possibility, on their basis, of developing technical and economic
The
The general flow chart of
General flow chart of
Characteristic features of
Assumptions and Implemented Calculation Models in the
Module  Purpose  Initial data  Assumptions / functional 


Calculation of onegroup neutron crosssections, various functionals, which are linear combinations, products and ratios of onegroup neutron crosssections and their uncertainties  Evaluated neutron data and covariance matrices, neutron spectrum (these data are placed in a specialised database of evaluated neutron data of actinide nuclei)  The module contains a set of evaluated neutron data and covariance matrices for the main actinide nuclei in the GENDF and BOXER formats (for covariance matrices), a set of standardized neutron spectra (fission, Maxwell, Fermi, etc.) and neutron spectra characteristic of various types of power reactors (the spectra can be specified in both analytical and tabular forms). 

Calculation of nuclide composition evolution (mass and concentration), activity, radiotoxicity, heat release, neutron and gamma sources of nuclear fuel  Initial isotopic composition of the fuel, onegroup neutron fluxes and neutron crosssections, both determined at various stages of fuel irradiation in the reactor and onegroup flux and crosssections averaged over the entire irradiation cycle and constant in time, specific power density, nuclear fuel burnup  Basic set of actinide nuclei: ^{234}U, ^{235}U, ^{236}U, ^{238}U, ^{237}Np, ^{238}Pu, ^{239}Pu, ^{240}Pu, ^{241}Pu, ^{242}Pu, ^{241}Am, ^{242m}Am, ^{243}Am, ^{242}Cm, ^{243}Cm, ^{244}Cm, ^{245}Cm, ^{246}Cm, ^{247}Cm, ^{248}Cm. Basic set of fission and activation products: ^{3}H, ^{14}C, ^{36}Cl, ^{54}Mn, ^{55}Fe, ^{60}Co, ^{59}Ni, ^{63}Ni, ^{79}Se, ^{85}Kr, ^{87}Rb, ^{90}Sr, ^{93}Mo, ^{94}Nb, ^{93}Zr, ^{98}Tc,^{99}Tc, ^{102}Rh, ^{106}Ru, ^{107}Pd, ^{110m}Ag, ^{113m}Cd, ^{121m}Sn, ^{125}Sb, ^{126}Sn, ^{125m}Te, ^{127m}Te, ^{126}Sn, ^{129}I, ^{134}Cs, ^{135}Cs, ^{137}Cs, ^{144}Ce, ^{146}Pm, ^{147}Pm, ^{146}Sm,^{147}Sm, ^{151}Sm, ^{152}Eu, ^{154}Eu, ^{155}Eu, ^{166m}Ho. Output data (masses and concentrations of the main actinides, fission products, radioactivity, decay heat, radiotoxicity, neutron and gamma radiation) are given for the end of the irradiation cycle, after cooling, for the 100th, 1000th and 10000th years. The functionality for estimating the nuclear data and technological uncertainty of the design characteristics is implemented. 

Calculation of the values and uncertainties of the corrections for the nuclear fuel enrichment and the total neutron flux, taking into account the conservation of the fraction of heavy nuclei in the fuel, reactivity and power of the reactor plant  Fuel isotope composition (design and actual), onegroup neutron crosssections, covariance matrices and neutron flux  Various methods for estimating the enrichment and total neutron flux corrections and their uncertainties are implemented in order to select the most appropriate method for its subsequent implementation. The uncertainties of the corrections associated with the initial neutron data are estimated. 

Calculation of material flows and needs for 
Dynamics of commissioning and decommissioning of power units, parameters of fuel use and SNF/RW production, isotope composition of fresh and spent fuel, characteristics of the strategy for handling SNF/RW, fissile materials, principles of prioritisation/management of stocks and reserves of nuclear materials  It is possible to take into account the radioactive decay of nuclides in external part of the 

Calculation for the 
Dynamics of commissioning and decommissioning of power units, technical and economic parameters of power units, material flows and needs for 
It is possible to consider different distributions of capital costs (uniform, sinusoidal distribution, distribution of a second degree polynomial, arbitrary distribution), adjust capital costs for units that remain in operation beyond the forecast horizon, and account for depreciation deductions during the operation of historical capacities. It is also possible to evaluate the uncertainty of economic indicators caused by the uncertainty of the initial cost data (uniform and triangular distribution of costs, correlated and uncorrelated distributions of input values). 
The
There are also versions of
Work with
The potential user of
The software modules were verified using software tools similar in functionality (Modelling Nuclear Energy Systems with MESSAGE, INPRO Methodology, Nuclear Fuel Cycle Simulation System). Identical results were obtained for similar model assumptions and initial data.
The
Using
It is shown that, under comparable conditions, Option 1 (without taking into account the RW production over time) gives an underestimated time for reaching the given reference level by the selected indicator compared to Option 2 (taking into account the RW accumulation over time) (Fig.
Radiotoxicity of radioactive waste (including fission products, activation products, actinides) upon oral intake of radionuclides into the body for the considered
VVER(100%): share of VVERTOI = 100%;
VVERmox(10%): shares of VVERTOI, VVERTOI MOX = 90 and 10%;
VVERmox(30%): shares of VVERTOI, VVERTOI MOX = 70 and 30%;
VVERmox(50%): shares of VVERTOI, VVERTOI MOX = 50 and 50%;
BN(20%): shares of VVERTOI, BN = 80 and 20%;
BN(50%): shares of VVERTOI, BN = 50 and 50%;
BN(90%): shares of VVERTOI, BN = 10 and 90%;
VVERmox(10%) BN(20%): shares of VVERTOI, VVERTOI MOX, BN = 70, 10 and 20%;
VVERmox(50%) BN(20%): shares of VVERTOI, VVERTOI MOX, BN = 30, 50 and 20%;
VVERmox(10%) BN(50%): shares of VVERTOI, VVERTOI MOX, BN = 40, 10 and 50%.
It is shown that, when the assessment of
Key Performance Indicators of the 10
Scenario (technology share in 2100 is in parentheses) / indicator  Cumulative uranium consumption, kt  Cumulative needs for uranium enrichment services, 10^{6} SWU  Cumulative needs for spent fuel reprocessing services, kt h.m.  Amount of SNF in 2100, kt h.m.  Amount of RW in 2100, kt h.m.  Amount of plutonium in the 
Amount of depleted uranium in 2100, kt  

VVER(100%)  787.65  666.75  0  126.98  0  1.09  1669.03  29.48 
VVERmox(10%)  782.92  662.72  27.36  106.12  26.92  0.84  1658.34  29.89 
VVERmox(30%)  776.18  656.97  71.81  69.11  70.76  0.54  1644.80  30.40 
VVERmox(50%)  772.07  653.46  92.71  51.06  91.42  0.41  1638.11  30.57 
BN(20%):  658.10  556.25  12.15  111.54  10.96  1.02  1544.24  29.53 
BN(50%):  492.27  414.81  41.77  77.70  38.93  0.91  1384.26  30.22 
BN(90%):  284.97  237.99  100.28  13.96  95.37  0.76  1184.07  31.09 
VVERmox(10%) BN(20%)  651.51  550.63  346.08  81.58  46.76  0.77  1531.93  30.29 
VVERmox(50%) BN(20%)  640.97  541.64  126.27  14.46  123.68  0.34  1511.78  31.57 
VVERmox(10%) BN(50%)  470.99  396.66  79.63  44.59  76.26  0.65  1359.36  31.70 
Type of 


LUAC  LUOM  LUFC 


LWR*  37.6±9.3  12.2±1.2  8.9±2.3  58.7±9.6 
LWR**  37.6±9.5  12.2±1.2  9.9±2.3  59.8±9.8 
HWR*  36.2±9.1  12.2±1.3  10.6±2.0  59.2±9.3 
HWR**  36.2±9.1  12.2±1.2  17.6±3.2  65.8±9.8 
ALWR*  35.4±8.8  11.6±1.2  6.7±1.5  53.8±9.0 
ALWR**  35.3±8.7  11.6±1.2  7.5±1.5  54.5±9.1 
FR1  40.2±12.0  12.5±1.2  13.5±2.4  66.2±12.4 
FR2  40.0±12.1  12.5±1.2  14.2±2.4  67.3±12.4 
AFR  40.4±12.1  12.6±1.2  8.9±1.5  61.4±12.1 
FRU  40.4±12.0  12.6±1.2  12.9±2.0  65.7±12.2 
* — SNF storage in a centralised storage facility outside the reactor building throughout the entire life cycle, ** — final SNF disposal in deep geological formations after 5 years of cooling LUAC is the levelized unit life cycle amortization cost; LUOM is the levelised unit life cycle operation and maintenance cost; LUFC is the levelized unit life cycle fuel cost.
Three types of thermal reactors (LWR, HWR and ALWR) operating in an oncethrough
LWR is a PWR type reactor with a burnup of 45 GW∙day/t h.m., fuel enrichment of 4%, a specific core energy density of 38.5 MW/t, and a capacity factor of 85%.
ALWR is an advanced LWR with higher fuel burnup; compared to LWR, equilibrium fuel loading in ALWR is 30% less than in LWR, initial fuel enrichment is 3.4%, equilibrium fuel enrichment is 4.95%.
HWR is a pressurised heavy water nuclear reactor with a burnup of 7 GW∙day/t h.m., fuel based on natural uranium, a specific power density of 24.0 MW/t, and a capacity factor of 85%.
FR1 is a sodiumcooled fast reactor with a breeding factor close to unity and an average fuel burnup (core and blankets) of about 38 GW∙day/t h.m.
FR2 is a prototype sodiumcooled fast breeder reactor with an average breeding factor of 1.16 and an average fuel burnup (core and blankets) of about 31 GW∙day/t h.m.
AFR is a commercial sodiumcooled fast reactor with an average breeding factor of 1.2 and an average (core and blankets) fuel burnup of 54 GW∙day/t h.m. Unlike FR1 and FR2, fresh AFR fuel contains about 1% minor actinides (MA).
FRU is a leadcooled fast reactor that uses enriched uranium fuel (enrichment of about 15% in ^{235}U) for initial core loading and first refuelling; subsequent SNF reprocessing and the use of secondary nuclear fuel (Pu + U + MA) are assumed. The blanket is not provided. The breeding factor is 1.05, fuel burnup is about 72.8 GW∙day/t h.m.
Based on the results of assessing the levelised unit energy cost and with account taken of the uncertainty in its values due to the spread in cost data, it can be concluded that it is impossible to make an unambiguous judgment about the greatest attractiveness of a particular concept of fast reactors, relying only on the analysis of the levelised unit energy cost, and it is also incorrect to make categorical statements about the lower economic efficiency and competitiveness of fast reactors compared to thermal reactors.
The nuclear energy system modelling application package (
Russian text published: Izvestiya vuzov. Yadernaya Energetika (ISSN 02043327), 2022, n. 2, pp. 148–160.