Validation of zirconium isotopes (n, g) and (n, 2n) cross sections in a comprehensive LR-0 reactor operative parameters set. (October 2017)

• Record Type: Journal Article
• Authors: Košťál, Michal; Schulc, Martin; Rypar, Vojtěch; Losa, Evžen; Burianová, Nicola; Šimon, Jan; Mareček, Martin; Uhlíř, Jan
• Is Part Of: Applied radiation and isotopes. Volume 128(2017:Oct.)
• Page Start: 92
• Page End: 100
• Publication Date: 2017-10
• Subjects: Cross section measurement -- Nuclear data -- Reactor dosimetry -- LR-0 -- Sample irradiation -- Zirconium cross section -- 90Zr(n, 2n) reaction, PFNS of 235U; Radiology -- Periodicals; Radiation -- Industrial applications -- Periodicals; Nuclear chemistry -- Periodicals; Internet resource; Periodical; 660.298
• DOI: 10.1016/j.apradiso.2017.06.023
• Languages: English
• ISSNs: 0969-8043

Abstract

Abstract: Zirconium is an important material used in most of reactor concepts for fuel cladding. Thus the knowledge of its cross section is important for reliable prediction of fuel operation. Also 90 Zr(n, 2n) reaction, is included in IRDFF files as dosimetry cross section standard. Due to its very high threshold, 12.1 MeV, it is suitable for measurement of high energy neutrons. One of possible interesting applications is also evaluation of prompt fission neutron spectra in 235 U and 238 U what is under auspices of the International Atomic Energy Agency in CIELO project. The experimental values - obtained with the LR-0 nuclear reactor - of various zirconium cross sections were compared with calculations with the MCNP6 code using IAEA CIELO, ENDF/B-VII.0, JEFF-3.1, JEFF-3.2, JENDL-3.3, JENDL-4, ROSFOND- 2010, and CENDL-3.1 transport libraries combined with the dosimetry cross sections extracted from the IRDFF library. Generally, the best C/E agreement for 90 Zr(n, 2n) cross section, was found with the IAEA CIELO 235 U evaluation that includes an updated prompt fission neutron spectra in the evaluated data file. The cross section of this reaction averaged over LR-0 spectra was determined being 28.9 ± 1.2 µb, corrected to spectral shift, spectral averaged cross section in 235 U was determined to be 0.107 ± 0.005 mb. Notable discrepancies were reported in both 94 Zr(n, g) and 96 Zr(n, g). Highlights: Determination of 89 Zr reaction rate in irradiated ZrO2 sample. Experimental spectral average cross section of 90 Zr (n, 2n) reaction. Calculation of reaction rate 90 Zr (n, 2n) reaction. Calculation and measurement of 94 Zr(n, g) and 96 Zr(n, g) reaction rates. Discrepancies between calculation and experiment. Hafnium contamination of ZrO2 sample.