Studies of the thermal decomposition of NaBrO/sub 3/ were extended to include material pre-irradiated with Co/sup 60/ and reactor irradiations. The primary effect of the irradiation appears to be an enhancement of the melting rate of the eutectic formed between NaBrO/sub 3/ and the product NaBr, and is accompanied by an enhanced decomposition rate. The conclusion reached with unirradiated material that alternate decomposition routes exist such as at dislocations and other defects is strengthened. (auth)