Calculation of Low-Energy Reactor Neutrino Spectra for Reactor Neutrino Experiments

Title & Authors
Calculation of Low-Energy Reactor Neutrino Spectra for Reactor Neutrino Experiments
Riyana, Eka Sapta; Suda, Shoya; Ishibashi, Kenji; Matsuura, Hideaki; Katakura, Jun-ichi;

Abstract
Background: Nuclear reactors produce a great number of antielectron neutrinos mainly from beta-decay chains of fission products. Such neutrinos have energies mostly in MeV range. We are interested in neutrinos in a region of keV, since they may take part in special weak interactions. We calculate reactor antineutrino spectra especially in the low energy region. In this work we present neutrino spectrum from a typical pressurized water reactor (PWR) reactor core. Materials and Methods: To calculate neutrino spectra, we need information about all generated nuclides that emit neutrinos. They are mainly fission fragments, reaction products and trans-uranium nuclides that undergo negative beta decay. Information in relation to trans-uranium nuclide compositions and its evolution in time (burn-up process) were provided by a reactor code MVP-BURN. We used typical PWR parameter input for MVP-BURN code and assumed the reactor to be operated continuously for 1 year (12 months) in a steady thermal power (3.4 GWth). The PWR has three fuel compositions of 2.0, 3.5 and 4.1 wt% $\small{^{235}U}$ contents. For preliminary calculation we adopted a standard burn-up chain model provided by MVP-BURN. The chain model treated 21 heavy nuclides and 50 fission products. The MVB-BURN code utilized JENDL 3.3 as nuclear data library. Results and Discussion: We confirm that the antielectron neutrino flux in the low energy region increases with burn-up of nuclear fuel. The antielectron-neutrino spectrum in low energy region is influenced by beta emitter nuclides with low Q value in beta decay (e.g. $\small{^{241}Pu}$) which is influenced by burp-up level: Low energy antielectron-neutrino spectra or emission rates increase when beta emitters with low Q value in beta decay accumulate Conclusion: Our result shows the flux of low energy reactor neutrinos increases with burn-up of nuclear fuel.
Keywords
Pressurized Water Reactor (PWR);Low energy antielectron neutrino spectra;MVP-BURN;
Language
English
Cited by
References
1.
Wei L, Ishibashi K, Arima H, Iijima T, Katano Y, Naoi Y. Possible detection of natural neutrinos by use of small apparatus, J. Nucl. Sci. Technol. 2004;4:487-490.

2.
Nagaya Y, Okumura K, Mori T, Nakagawa M. MVP/GMVP II: General purpose Monte Carlo codes for neutron and photon transport calculations based on continuous energy and multigroup methods. JAERI 1348. 2004;1-2.

3.
Okumura K, Nagaya Y, Mori T. MVP-BURN: Burn-up calculation code using a continues energy Monte Carlo code MVP. Japan Atomic Energy Research Institute; Draft Report for JAEA. 2006;1-2.

4.
Shibata K, et.al. Japanese evaluated nuclear data library version 3 Revision-3: JENDL-3.3. J. Nucl. Sci. Technol. 2002;39:1125.

5.
Katakura J. JENDL FP decay data file 2011 and fission yields data file 2011. JAEA-Data/Code 2011-025. 2012;1-3.

6.
Nishimura K, Ishimoto S, Arima H, Ishibashi K, Katakura J. Brief calculation of neutrino energy spectra by the use of nuclear data files. J. Nucl. Sci. Technol. 2004;4:522-525.

7.
Araki T, et al. Measurement of neutrino oscillation with KamLAND: Evidence of spectral distortion. Phys. Rev. Lett 94. 2005;081801:2.

8.
Bhalla CP, and Rose ME. Table of electronic radial function at the nuclear surface and tangents of phase shifts. Oak Ridge National Laboratory Report. Report no. ORNL 32071961;5-6.

9.
Copper EP, Rogers FT. Composite of experimental measurements of the energy-distribution among beta-particle from tritium. Phys. Rev. 1950;77:402

10.
United States Nuclear Regulatory Commission. Radiological toolbox user's guide. NUREG/CR-7166. 2013;6-9.