According to regulatory requirements, when carrying out handling operations with spent nuclear fuel (SNF), prevention of damage to the spent fuel assemblies (SFA) and especially fuel elements shall be ensured. For this purpose, it is necessary to exclude the risk of SFA falling, SFA uncontrolled displacements, prevent mechanical influences on SFA, at which their damage is possible. Special requirements for handling equipment (in particular, cranes) to exclude these dangerous events, the requirements for equipment strength, resistance to external impacts, reliability, equipment design solutions, manufacturing quality are analyzed in this work. The requirements of Ukrainian and U.S. regulatory documents also are considered. The implementation of these requirements is considered on the example of handling equipment, in particular, spent nuclear fuel storage facilities. This issue is important in view of creation of new SNF storage facilities in Ukraine. These facilities include the storage facility (SFSF) for SNF from water moderated power reactors (WWER): a Сentralized SFSF for storing SNF of Rivne, Khmelnitsky and South-Ukraine Nuclear Power Plants (СSFSF), and SFSF for SNF from high-power channel reactors (RBMK): a dry type SFSF at Chornobyl nuclear power plant (ISF-2). After commissioning of these storage facilities, all spent nuclear fuel from Ukrainian nuclear power plants will be placed for long-term “dry” storage. The safety of handling operations with SNF during its preparation for long-term storage is an important factor.

The article deals with construction of a mathematical model of combined motion of a rigid pipeline conveying liquid. The pipeline performs rotation about the longitudinal axis. For different velocities of liquid flow and pipeline rotation we determine special features of the system dynamic behavior. It was shown that oscillations in the system are developed near rectilinear and two alternative positions of dynamic equilibrium. Characteristics of phenomena manifested on transition to oscillations relative to alternative states are given.

The paper addresses the description of computer model for the spent fuel assemblies storage system in SCALE and MCNP codes, as well as the results in selection of conservative assumptions made to justify the nuclear safety of moving, transport and storage operations with the VVER-1000 spent nuclear fuel (SNF) in designed Centralized Spent Fuel Storage Facility (CSFCF). When justifying the nuclear safety, it is necessary to confirm that the maximum value of the effective multiplication coefficient K eff in SNF storage systems is kept below specified limit of 0.95 in any design-basis operation mode. The paper presents calculation results and analysis on the selection of the most conservative conditions of neutron multiplication leading to the maximum value of Keff.