Abstract: A stainless steel clad 9-rod assembly fabricated by The Babcock & Wilcox Company was irradiated in a boiling water loop of the General Electric Test Reactor. A post-irradiation examination revealed no significant dimensional changes on the fuel rods. the results of mass spectrometric analysis made of the pelletized UO2 fuel indicated a maximum burnup of 11,500 MWD/tonne was attained by Rod B-4 during the exposure.An x-ray diffraction examination of an unirradiated fuel sample revealed the presence of UN2 and U2N3 phases. Metallographic examination of the irradiated microstructures revealed similar second-phase particles.

Quarterly progress report discussing activities related to the Vallecitos Boiling Water Reactor (VBWR) and related facilities

For an experiment to measure the magnetic moment of the Λ hyperon, it was necessary to extract the external beam of the Cosmotron with maximum efficiency and with minimum time duration. To accomplish this end, the standard external beam of the machine was supplemented with the Rapid Beam Ejector. It was found that, unfortunately, the ejection efficiency of the beam was less than normal when the RBE was used. Measurements of the ejection efficiency were made by irradiating polyethylene foils at the second focus of Beam 1 with 3 BeV protons. The external beam was tuned up and optimized in a standard manner. It was found that the ratio of the number of protons ejected with the RBE to the number ejected without the RBE was 0.3 in one run and 0.22 in another try. It was also observed that the RBE did not shift the position of the external proton beam focus to within ± 1/8 in.