EDN: CMOTIA
Authors & Affiliations
Vlaskin G.N., Khomyakov Yu.S.
Rosatom “Innovation and Technology Center of the PRORIV Project”, Moscow, Russia
Vlaskin G.N. – Researcher. Contacts: 1, Ramensky b-r, Moscow, Russia, 107140. Tel.: +7 (962) 979-74-10; e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it., This email address is being protected from spambots. You need JavaScript enabled to view it..
Khomyakov Yu.S. – Head of Department, Dr. Sci. (Phys.-Math.).
Abstract
Assessing the radiation hazard when working with radioactive materials is a priority task that requires modeling the formation, calculation of the intensity, and spectrum of the emitted penetrating radiation. The RASTAS complex is designed to calculate neutron and photon radiation sources based on initial data on the composition of radioactive materials and generate a file of calculated radiation intensity and spectrum values. The sources of ionizing radiation may include technological radioactive materials, including fuel and structural materials, coolant and gas circuits of the reactor, fuel elements, fuel assemblies, absorber assemblies, and other irradiated elements of the reactor that are sent to processing, reprocessing, and waste management facilities at fuel cycle enterprises. The RASTAS software package is based on the upgraded NEDIS, STORM, and SOGAM codes, which calculate, respectively, the neutron source (α, n)-reaction and spontaneous fission, as well as the spontaneous fission photon source, the electron and positron bremsstrahlung photon source, and the alpha and beta decay photon source for radioactive nuclei. A brief description of the software tools is provided. The source power and neutron spectrum of spontaneous fission of actinides are calculated using the Watt formula. This involves using data on the half-life of actinides, the probability of spontaneous fission, and parameters that determine the spectral characteristics. In this case, data on the half-life of actinides, the probability of spontaneous fission, and the parameters that determine the spectral characteristics are used. The neutron source power from the (α, n)-reaction is calculated using data on the target's stopping power for α-particles of specific energy and data on the integrated cross-section for neutron production when α-particles interact with the target material. Neutron spectra from (α,n)-reactions are calculated using data on the target's stopping power for α-particles of a certain energy and using the kinematic equations of α-particle interactions with light isotope nuclei in the center-of-mass system and the corresponding cross sections for neutron production with exit to individual levels of residual reaction nuclei. The power and spectrum of photon radiation are calculated based on a library of gamma line data for individual nuclides, obtained from the ENDF-B7.1 and ENSDF files for 1280 isotopes. The power and spectrum of photon of bremsstrahlung is calculated based on the method of photon formation during the braking of charged particles (electrons and positrons) for an arbitrary user-defined medium. The RASTAS complex can be used both independently to assess the power of radiation sources and the radiation characteristics of materials, spent nuclear fuel, and radioactive waste, and as part of the COMPLEX software package for radiation safety justification to solve problems of neutron and gamma-ray transport.
Keywords
software package, neutrons, photons, calculations, radiation characteristics, radioactive waste, SNF, radiation safety, nuclear physical data
Article Text (PDF, in Russian)
References
- Scale: A Comprehensive Modeling and Simulation Suite for Nuclear Safety Analysis and Design, ORNL/TM-2005/39, Version 6.1, Oak Ridge National Laboratory, Oak Ridge, Tennessee, June 2011. Available from Radiation Safety Information Computational Center at Oak Ridge National Laboratory as CCC-785.
- Vlaskin G.N. Programma NEDIS2.0 dlya rascheta vykhoda i spektrov neytronov, obrazuyushchikhsya v (α, n)-reaktsiyakh na yadrakh legkikh elementov i za schet spontannogo deleniya [NEDIS2.0 code to calculate yields and spectra of neutrons produced in light element nuclei (α, n) reactions and spontaneous fission]. Preprint VNIINM 06-1. Moscow, VNIINM Publ., 2006.
- Vlaskin G.N., Khomyakov Yu.S. (α, n) Neutron Spectra on Thick Light Targets. Atomic Energy, 2021, vol. 130, issue 2, pp. 98–110. DOI: 10.1007/s10512-021-00781-0.
- Firestone R.B. Table of Isotopes 8th Edition. Vol. 1. John Wiley and Sons Inc., 1996.
- ENDF/B-VII.1 Evaluated Nuclear Data Library. Available at: http://www.nndc.bnl.gov/endf/b7.1/index.html (accessed 17.07.2025)
- Vlaskin G.N., Khomyakov Y.S., Bulanenko V.I. Neutron Yield of the Reaction (α, n) on Thick Targets Comprised of Light Elements. At Energy, 2015, vol. 117, issue 5, pp. 357–365. DOI: https://doi.org/10.1007/s10512-015-9933-5.
- Ziegler J.F. The Stopping and Ranges of Ions in Matter. Vol. 4. Pergamon, 1977.
- Ziegler James. SRIM & TRIM. The Stopping and Range of Ions in Matter. Pergamon, 2013. 324 p.
- Chard P.M.J. and Croft S. A database of 240Pu effective and 235U effective coefficients for various fertile and fissile isotopes. Proc. of the 19th Annual ESARDA Symposium on Safeguards and Nuclear Material Management. France, May 13–15, 1997, pp. 389–396.
- Holden N.E., Hoffman D.C. Spontneous Fission Half-Lives for Ground-State Nuclides. IUPAC Technical Report. Pure. Appl. Chem., 2000, vol. 72, no. 8, pp. 1525–1562.
- Bonetti R. et al. First observation of spontaneous fission of 232U. Phys. Rev C, 2000, vol. 62, pp. 047304–047307.
- Holden N.E., Zucker M.S. A Reevaluation of the Average Prompt Neutron Emission Multiplicity (Nubar) values from Fission of Uranium and Transuranium Nuclides. BNL-NCS-35513. Brookhaven National Laboratory, 1985.
- Santi P. and Miller M. Reevaluation of Prompt Neutron Emission Multiplicity Distributions for Spontaneous Fission. Nucl. Sci. and Eng., 2008, vol. 160, pp. 190–199.
- Simakov S., Verpelli M., Otsuka N. Update of the nuclear data for the neutron emissions for actinides of interest in safeguards. Nuclear Data Section, IAEA, 2015. Available at: https://www-nds.iaea.org/sgnucdat/SF_n-Yield_20150313.pdf (accessed 17.07.2025).
- Stephen Croft, Andrea Favalli. Review and Evaluation of the Spontaneous Fission Half-lives of 238Pu, 240Pu and 242Pu and the Corresponding Specific Fission Rates. Nuclear Data Sheet, 2021, vol. 175, pp. 269–287. DOI: https://doi.org/10.1016/j.nds.2021.06.003.
- Wagemans C. The Nuclear Fission Process. Boca Raton, Florida: CRC Press, Inc., 1991.
- Valentine T.E. MCNP-DSP User’s Manual. ORNL/TM-13334, R2, Oak Ridge National Laboratory, 2000.
- Maienschein F.C., Peelle R.W., Love T.A. Neutron Phys. Ann. Prog. Rep. for Sept. 1, 1958. ORNL-2609. Oak Ridge National Laboratory, 1958.
- Herbert Goldstein. Fundamental Aspects of Reactor Shielding. Massachussetts: Addison-Wesley Publishing Company, Inc. Reading, 1959. 416 p.
- Seltzer S.M. and Berger M.J. Bremsstrahlung energy spectra from electrons with kinetic energy 1 keV – 10 GeV incident on screened nuclei and orbital electrons of neutral atoms with z = 1–100. Atomic Data and Nuclear Data Tables, 1986, vol. 35, issue 3, pp. 345–418.
- Bethe H., Heitler W. Proceeding of the Royal Society of London, Series A: Mathematic and Physical Science, 1934, vol. 146, pp. 83–112.
- Pratt R.H., Tseng H.K., Lee C.M. and Kissel L. Bremsstrahlung energy spectra from electrons of kinetic energy 1 keV ≤ T1 ≤ 2000 keV incident on neutral atoms 2 ≤ Z ≤ 92. Atomic Data and Nuclear Data Tables, 1977, vol. 20, pp. 175–209.
- Davies H., Bethe H.A. and Maximon L.C. Theory of bremsstrahlung and pair production. II. Integral cross section for pair production. Phys. Rev. 1954, vol. 93, pp. 788–795.
- Kim L., Pratt R.H., Seltzer S.M. and Berger M.J. Ratio of positron to electron bremsstrahlung energy loss: an approximate scaling law. Phys. Rev. A, 1986, vol. 33, pp. 3002–3009.
- Francesco Salvat, José M. Fernández-Varea, Josep Sempau. PENELOPE-2008: A Code System for Monte Carlo Simulation of Electron and Photon Transport. Workshop Proceedings. Barcelona, Spain, 30 June – 3 July 2008, OECD 2009, NEA No. 6416.
- Stopping Power for electrons and Positrons. ICRU Report 37, 1984. Tormoznaya sposobnost' elektronov i pozitronov. Doklad 37 MKRE: Per. s angl./Pod red. I.B. Keirim-Markusa [Stopping power of electrons and positrons. Report 37 ICRE: Trans. from English/Ed. by I.B. Keirim-Markus]. Moscow, Energoatomizdat Publ., 1987.
- Berger M.J., Coursey J.S., Zucker V.A., Change J. Stopping-Power and Range Tables for Electrons, Protons, and Helium Ions. ESTAR, PSTAR, and ASTAR databases. Washington, DC: National Institute of Standards and Technology, February 14, 2006. Available at: http://physics.nist.gov/PhysRefData/Star/Text/contents.html (accessed 17.07.2025).
- Knipp J.K., Uhlenbeck G.E. Physica, 1936, vol. 3, p. 425.
- Bloch F. On the continuous gamma-radiation accompanying the β-decay. Phys. Rev., 1936, vol. 50, p. 272.
- Chadick M.B., Herman M., Obložinský P., Dunn M.E., Danon Y., Kahler A.C., Smith D.L., Pritychenko B., Arbanas G., Arcilla R., Brewer R., Brown D.A., Capote R., Carlson A.D., Cho Y.S., Derrien H., Guber K., Hale G.M., Hoblit S., Holloway S., Young P.G. ENDF/B-VII.1 Nuclear Data for Science and Technology: Cross Sections, Covariances, Fission Product Yields and Decay Data. Nuclear Data Sheets, December 2011, vol. 112, issue 12, pp. 2887–2996.
- National Nuclear Data Center. Evaluated Nuclear Structure Data File (ENSDF). Brookhaven National Laboratory, 2012. Available at: https://www-nds.iaea.org/ensdf_base_files2012 (accessed 17.07.2025).
- Eckerman K., Endo A. ICRP Publication 107. Nuclear decay data for dosimetric calculations. Ann ICRP, 2008, vol. 38(3), pp. 7–96. DOI: 10.1016/j.icrp.2008.10.004.
- Matveev L.V., Center E.M. Uran-232 i yego vliyaniye na radiatsionnuyu obstanovku v yadernom toplivnom tsikle [Uranium-232 and its influence on the radiation situation in the nuclear fuel cycle]. Moscow, Energoatomizdat Publ., 1985.
UDC 621.039.58
Problems of Atomic Science and Technology. Series: Nuclear and Reactor Constants, 2025, no. 3, 3:2
