TALK ON THE ATOM AND THE THERMAL REACTOR
Mr. L.G. Hill (Member.)19th March 1982
In his opening remarks, Mr. Hill reminded those present that, in common with other fields of research, the nuclear physicist utilises certain concepts and convent ions which, though invaluable to him and his associates in the progression of ideas and in the exchange of experiences, are not necessarily accurate nor even tenable. Practical applications, though, as the result of a progression of physical experiments, did not suffer thereby. In short, nuclear devices worked satisfactorily even though ideas as to how or why they worked were not necessarily correct.
Nuclear studies commenced with Becquerel’s discovery of radio-active behaviour of uranium salts in 1896 and its subsequent progression by Rutherford, Soddy and others in the early years of this century. From this, theories as to the structure of matter were evolved which crystallised into concepts of the fundamental atom comprising a nucleus of an uncharged particle (neutron) and a negatively charged particle (electron) with positively charged particles (protons) circulating around in shells or orbits in the manner of miniature solar systems.
That such a concept is, in fact, fallacious is evident in that it assumes different kinds of electro-static charge, negative and positive, not having any mass in association with a fundamental and indivisible particle having both mass and dimension. As we all know, the terms ‘positive’ and ‘negative’ in relation to electrostatic charges or potentials are relative to the concentration of the charge, flow taking place from the higher charged to lower charged body until both are at a common level. We are not even certain if flow is from conventional positive to conventional negative or vice versa. It follows that all masses, regardless of size must carry a charge and a neutron, or uncharged particle.
As to the radiations from radio-active sources, these comprise alpha & gamma radiations – which are electromagnetic in nature and transmitted from particle to particle as electric currents without the particles moving – and beta particles which are actual particles with their resident charge moving at high velocities though normally below that of the transmission of electromagnetic radiation. Particles have a
kinetic energy relative to the source or target: electromagnetic radiation has none and its velocity is constant through the medium. As with all electromagnetic radiations, it will have wavelength. Because of the kinetic energy of particle streams, they will pass through solid bodies causing some damage but the alpha and gamma rays can be deflected, like light waves, by reflecting surfaces or absorbed as energy creating heat by solid bodies.
Mr. Hill went ,on to outline the two reactions between masses of radio active material in close association, fusion and fission, and how these reactions with the resulting omissions are controlled in nuclear reactors, the heat generated being utilised to raise steam for powering turbo-generators. Particle energies are absorbed in moderators, such as heavy water, – with the same chemical formula as ordinary ‘light’ water,
H2O except that the ‘hydrogen’ (deuterium) had double the element atomic
weight, or 20:18 as the molecular weights The radiant energies by the walls of the reactor chamber, cooled in turn by circulating gas or liquid transmitting it via a heat exchanger to the steam-raising boiler.Finally, he gave a brief summary of the British nuclear power stations since their inception in 1956 together with their efficiencies and prophesied that, within the next half century, a more direct method of separating the charges from the particle masses would be developed, on the principle of the thermionic valve, to give electrical outputs without the intervening steam-turbine-generator combination.
After a question and answer session, inevitably curtailed by shortage of time, Mr. Beeken proposed a vote of thanks to Mr. Hill for a fascinating address. The information imparted should enhance our enjoyment of the Dungeness visit.
TALK ON THE ATOM AND THE THERMAL REACTOR