TY - JOUR AU - B.K. Kozhakhmet, AU - G.G. Kulikov, AU - G.S. Nurbakova, AU - S.B. Rustembayeva, PY - 2019/06/10 Y2 - 2024/03/28 TI - USE OF MOLYBDENUM AS A STRUCTURAL MATERIAL OF FUEL ELEMENTS IN LEAD OR LEAD-BISMUTH EUTECTIC COOLED FAST REACTOR TO IMPROVE ITS SAFETY JF - Известия НАН РК. Серия физико-математическая JA - СФМН VL - IS - 3 SE - Статьи DO - UR - https://journals.nauka-nanrk.kz/physics-mathematics/article/view/1668 SP - 166-175 AB - <p>In our previous works has been described that the mean prompt neutron lifetime in fast reactors can<br>be significantly elongated [1,2]. But if the last parameter is not comparable with the time required for the heat<br>generated in the fuel elements to transport from a fuel to a coolant, feedback on the effect of changes in coolant<br>parameters on reactivity during this time will not have time to manifest. Here was studied that the thermal constants<br>of fuel elements can be shortened by using molybdenum as a structural material of fuel elements. Other aspects<br>related to the use of molybdenum in nuclear reactors have also been studied.<br>When performing the study the neutron-physical properties of isotopes of natural molybdenum (nuclear data<br>library JENDL-4.0) and thermal properties of metallic molybdenum were used.<br>The following results were obtained:<br>1. A method for reducing the thermal constant of fuel elements for light water and fast reactors by using<br>dispersion fuel in cylindrical fuel rods containing, for example, granules of metallic U-Mo-alloy into Mo-matrix was<br>proposed.<br>2. The necessity of molybdenum enrichment by weakly absorbing isotopes was shown.<br>3. Total use of isotopic molybdenum will be more than 50%.<br>4. Mo has a good corrosion resistance to Pb and Pb-Bi eutectic<br>A decrease in thermal constants of fuel elements, in combination with an increase in the mean prompt neutron<br>lifetimes in the absence of the heat transfer crisis in fast reactors, can be promising way for a better reactor operation<br>safety even under the conditions of the prompt neutron excursions.</p> ER -