Twenty-four-hour sweep tests have been carried out in flowing air at 200 and 400°C on deliberately defected UO2 fuel elements with 2.5-yr discharge times. At 200 C there was no diametral change, but at 400 °C, swelling and severe sheath cracking were observed. Neither short-lived fission products nor 134Cs, I37Cs, or 106Ru were detected above background. Maximum 85Kr release was ≤7.4 × 104 Bq (≤2 × 10-6 Ci).