An Experimental Investigation of the Elastic Dynamic Characteristics of a Model of an Ampoule for the Space Transportation of Radioactive Wastes at High Temperatures

Abstract

The dynamic elastic characteristics of an experimental physical model of an ampoule for the space transportation of radioactive wastes in the self-delivery mode, i.e., when the wastes are the primary energy source, are described. An experimental system is designed to investigate the characteristics of the model of the ampoule, and a procedure for investigating both the cold and heat-stressed state of the ampoule is developed. The amplitude-frequency characteristics of the ampoule model are obtained for different temperature situations.Considerable attention is being devoted at the present time to the problems involved in the space disposal of radioactive wastes [1][2][3]. This involves the problem of designing the spacecraft, constructionally arranged and constructionally strong systems, and the mechanical and dynamic characteristics of both the apparatus as a whole and of its components and aggregates. An investigation of the situations in which the radioactive wastes play the role of the primary energy source, providing the transport operations in the cosmos (the self-delivery mode) is particularly important [4][5]. The radioactive decay energy is converted into electrical energy and supplied to an electro-rocket motor of the spacecraft. In this case, the temperature conditions of the ampoule (as a source of energy) determine the efficiency of the structure not only from the point of view of its efficiency, but also from the point of view of its mechanical and dynamic characteristics (thermal strength, the oscillation spectrum and the forms of the frequencies), which have a considerable influence on the construction of the spacecraft as a whole. Hence, an investigation of the dynamic elastic characteristics of the ampoule with the radioactive wastes at increased temperatures becomes the new urgent problem when designing the spacecraft.Experimental System for Investigating the Model of the Ampoule in Cold and Thermally Stressed States. To investigate the elastic dynamic characteristics (EDC) of the cold state (the temperature of the ampoule walls is 293 K) and in the thermally stressed state (373-503 K) of the ampoule with the radioactive wastes, we developed a dynamic system ( Fig. 1) with different diagnostic equipment.The dynamic arrangement consists of the following: a Signal Star Vector II system for controlling the vibrational loads [6], which includes a personal computer (PC) using ABAQUS software, a generator and signal processing apparatus, a signal amplifier, a set of measuring and master sensors, a GW-V55/PA300E electrodynamic force exciter and a system for cooling it, and an emergency shutoff unit.

Technical aspects of designing a spacecraft for transporting radioactive waste

“…Для вывода РАО на орбиту захоронения можно использовать два варианта разгонного блока (РБ) [2,3]: 1) специализированный РБ на основе жидкостных ракетных двигателей максимальной надежности и повышенной грузоподъемности;…”

“…Основным преимуществом РБ на основе ЯЭРДУ является то, что исключается возврат контейнера с РАО на поверхность Земли в случае формирования импульса ошибочного вектора тяги [3]. Вместе с тем использование РБ с малой тягой позволяет обойтись без дополнительных систем обеспечения безопасности и транспортировать на орбиту захоронения только полезный груз (контейнер с РАО).…”

“…Конструктивно КА представляет собой последовательность узлов: контейнер, окруженный радиационной защитой, устройство отвода тепла от контейнера с РАО, энергодвигательная установка (ЭДУ) -химическая, ядерная, солнечная и т. п., система хранения и подачи рабочего тела для двигательного блока, двигательный блок, система управления, отсек с бортовой аппаратурой [3][4][5].…”

“…Исходя из значения начальной массы КА, выбираются варианты, позволяющие осуществить транспортную операцию. В результате формируются требования к величинам удельной массы агрегатов КАγ эл , при которых сумма масс агрегатов не превышает значение заданной начальной массы КА [3,4].…”