APPARATUS FOR THE STUDY OF FISSION-GAS RELEASE FROM NEUTRON-ACTIVATED FUELED GRAPHITE

A simple laboratory apparatus for the study of fissiongas release from neutron-activated fueled graphite was developed. Xenon-133 released from a heated specimen is carried in a helium sweep gas to a charcoal trap, where the accumulated activity is monitored continuously by a scintillation detector, ratemeter, and pen recorder. The maximum specimen temperature (2500 deg F) is achieved in 10 min with an induction heater. All instrumentation is commercially available. Data for several neutron-activated fueled-graphite specimens heated in the range from 800 to 2500 deg F are presented to illustrate the typical results obtained with the apparatus. (auth

ALUMINA COATING OF UOsup2sup 2 SHOT BY HYDROLYSIS OF ALUMINUM CHLORIDE VAPOR

Uniform, dense coatings of alumina about 5 to 150 mu thick were applied to uranium dioxide particles 44 to 350 mu in diameter by hydrolysis of aluminum chloride vapor in a fluidized bed of the particles at 1830 deg F. The coated particles were resistant to nitric acid leaching, to oxidation in 1830 deg F air, and to thermal cycling from 6OO to 2500 deg F. After low neutron exposures, the coated particles showed excellent fission-gas retention at temperatures up to 2400 deg F in inert gas. Although not optimized in the study, the coating process appears to have commercial feasibility. (auth

High-Temperature Irradiation of Metals and Graphite in Flowing Helium

As part of the coolant-core evaluation studies in an early phase of the Maritime Gas-Cooled Reactor program, nickel. K-Monel, niobium-1 wt.% zirconium, and graphite were irradiated in a convective flow of helium. A capsule of novel design was used to study the corrosion of the metals at 1500 and 960 ction prod- F in a 243-hr BRR experiment. Four heliumfilled quartz tori, containing the specimens, were encapsulated in a stainless steel capsule. A convective flow of helium was maintained in the closed tori by heating one leg of each torus to 1500 and the other at 960-F. Zirconium foilwas placed in two of the tori to getter gaseous impurities. No attack of the nickel and niobium-1 wt.% zirconium was observed at either temperature. Metallographic examination did show a 1 to 2.5- mil attack of the K-Monel at 1500 ction prod- F in a torus containing no getter. (auth