Irradiation of Uranium Monocarbide

Uranium carbide containing about 5.2 w/o carbon has been irradiated to nominal burnups of 1000 and 5000 Mwd/ton of carbide. The results are generally encouraging, although some cracking has been observed. The observed density decreases were about the same at 1000 and 5000 Mwd/ton irradiations, being 0.7 to 2.5 and 0.6 to 2.5% respectively. The problems and questions raised by these irradiations are discussed. Additional irradiations are planned to study the effects of composition and of burnups to 15,000 Mwd/ton of carbide.