On 7/2/14 a report of a release of ethyl acetate was received in the Region II REOC. The report stated that the release, amounting to approximately 27,000 lbs, occurred over a period of time from 6/19/14 to 6/23/14. The release was from a double compartmented horizontal storage tank. One compartment contained ethyl acetate while the other compartment was empty and being steam cleaned. Shift workers failed to inform the on-coming shift that the tank was being steam-cleaned, consequently the steam was kept on for 5 days. The prolonged hi-pressure steam being in contact with the uninsulated, bifurcating tank wall for five days resulted in overheating the ethyl acetate in the adjoining compartment. The boiling liquid was vented through the atmospheric top vent over the five day period. The release was eventually noticed when a truck arrived to pick up a load of ethyl acetate. When the liquid level in the tank was checked prior to loading the truck the lost volume was noted and measured. When the amount of missing ethyl acetate was calculated the facility noted that the RQ had been exceeded and notified the NRC on 7/1/14.
OSCs on duty in the REOC reviewed the NRC report and decided to investigate the cause of the release as well as the seeming delay in discovering the release.
Based on the interview with facility environmental and engineering staff a referral of this case will be made to enforcement personnel within the Response and Prevention Branch.
