Progress report of Physics Division. 1st October 1976 - 30th September 1977. Acting Division Chief - Mr. W. Gemmell

The maturity of the nuclear industry is exemplified by the increasingly large effort required to improve upon existing levels of knowledge or understanding. Our experiment to provide an accurate measurement of the californium fission neutron spectrum has been delayed by the necessity to investigate the many small correction effects and validate the new features introduced. The same type of painstaking analysis has become necessary in the collaborative studies with Oak Ridge National Laboratory on neutron capture cross sections. Investigation of background, interference and experimental techniques has led to significant revisions of the data and, again, emphasizes the care necessary before such data becomes incorporated into international data collections. A continuing worry in all of this is the adequacy of our major equipment for continuation in these fields. These worries have been lessened by the excitement of some applications ranging from investigations of gas/liquid inclusions in rocks and minerals, to the quite spectacular radiographs of uranium distribution in kidney sections, using solid state track devices. Although our interests lie primarily with an understanding of the polluting processes in uranium mine tailings, it has become obvious that the problem is a general and widespread one. Few physics investigations have been recorded and yet diffusion processes appear to be of prime importance. Most, if not all, the pollution arises from heavy metals other than uranium. interest in reactor safety has moved steadily away from the neutronics to the study of the hydrodynamics of the loss of coolant accident and to an understanding of the convection processes in transient heat transfer. Interesting problems in classical physics have arisen. The main code development interest has been with a new method of numerical iteration which offers prospects for reducing the convergence time of large, three-dimensional codes. Work on interactive computing methods has considerably improved the efficiency and flexibility of the Division's computer operations and many interesting ideas have arisen, some of which are being pursued vigorously. Most of the reactor physics work in the period has been involved with service type work on thorium. in the fuel cycle, safeguards and preliminary work on a new research reactor (author)