Authors & Affiliations
Korobeinikova L.V., Stogov V.Yu, Shaginyan R.A., Shakirov A.M.
A.I. Leypunsky Institute for Physics and Power Engineering, Obninsk, Russia
Korobeinikova L.V. – Senior Researcher.
Stogov V.Yu. – Senior Researcher.
Shaginyan R.A. – Research Engineer. Contacts: 1, pl. Bondarenko, Obninsk, Kaluga region, Russia, 249033. Tel.: +7 (484) 399-80-56; e-mail:
Shakirov A.M. – Research Intern.
Abstract
Fast-neutron nuclear reactors use a relatively small proportion of the core volume for the control rods. Materials with high neutron absorption cross-sections in the fast energy spectrum are used in the control system to ensure the necessary efficiency. Among such materials boron carbide stands out. This absorber is widely used with boron-10 content ranging from natural (about 20 %) to 97 %.
However, boron has a number of drawbacks, among which are the necessity of its foreign procurement, swelling under irradiation and essential loss of efficiency at burn-out. Thus, the question arises as to whether alternative materials should be considered as absorbents.
Since the 1980s both Russian and, after some time, Japanese specialists have been conducting research on hafnium hydride.
The geometric structure of the rod plays an important role in the development of new control rods. The position, shape and thickness of the absorber matter in determining the efficiency of control rods of various designs.
The paper presents the influence of the absorber location (inside the cell) on the rod efficiency. Three placement options are considered: a cylinder (limiting case of a ring) in the centre, a cylindrical ring and a cylindrical ring on the periphery.
Calculations show the preference for hafnium hydride in cells with a large cross section. The optimum ring thickness of 2.2 cm (with a width across flats of 18.1 cm) is also revealed.
Keywords
hafnium hydride, absorbing material, fast reactor, boron carbide, efficiency, cylindrical ring, control rods
Article Text (PDF, in Russian)
UDC 621.039.562.24
Problems of Atomic Science and Technology. Series: Nuclear and Reactor Constants, 2023, issue 3, 3:8