FLINT HILLS RESOURCES, LC

Incident Narrative

11/2024- FINAL REPORT UPDATED PART G-APPARENT CAUSE PART H-NARRATIVE: THE INVESTIGATION REVEALED THAT THE ACCUMULATED PARAFFIN ON THE TANK SHELL MELTED, FLOWED INTO THE SEAL AREA, AND AFTER A RAIN EVENT, DISPERSED TO THE ROOF DRAIN AND CONTAINMENT AREA. ________________________________________________________________________________ 10/11/2024 SUPPLEMENTAL REPORT TO UPDATE PART D.Q8. ESTIMATED COST TO OPERATOR. ________________________________________________________________________________ ON AUGUST 12, 2024, WHILE PERFORMING NIGHTLY ROUNDS, FHR OPERATIONS NOTICED A SHEEN LIKE SUBSTANCE INSIDE THE TANK 74 DIKE. BASED ON THE SITE ASSESSMENT, IT WAS DETERMINED THAT THIS WAS NOT AN ACTIVE RELEASE. OPERATIONS VERIFIED THAT THE DIKE DRAIN VALVES WERE CLOSED, AND THAT NO PRODUCT HAD MIGRATED OUTSIDE OF THE TANK 74 DIKE. OPERATIONS CONTACTED AN OSRO TO ASSIST WITH CLEAN-UP EFFORTS. ON AUGUST 13, 2024, AT APPROXIMATELY 0800, THE OSRO ARRIVED ONSITE. ON AUGUST 13, 2024, AT APPROXIMATELY 1000, FHR DETERMINED THAT THE ESTIMATED COST OF MAY EXCEED $50,000 DUE TO THE NEED FOR ADDITIONAL EXCAVATION AND AT 1005 A NOTIFICATION WAS MADE TO THE NRC. IT IS BELIEVED THAT DURING A HIGH RAIN EVENT, PARAFFIN TYPE PRODUCT WAS WASHED FROM THE TANK SHELL AND SEAL AREA WHICH MIGRATED TO THE FLOATING ROOF AND INTO THE TANK 74 DIKE THROUGH THE ROOF DRAIN. CLEAN-UP ACTIVITIES, AND REMOVAL OF IMPACTED SOIL OCCURRED BETWEEN AUGUST 12 THROUGH AUGUST 22. A CONTRACTOR WAS DEPLOYED TO REMOVE THE PARAFFIN FROM THE ROOF DRAIN HOSE, THE PRIMARY SEAL AND THE SHELL. AN INSPECTION OF THE PRIMARY AND SECONDARY SEAL WAS COMPLETED PRIOR TO PLACING THE TANK BACK IN SERVICE. THE INVESTIGATION IS CURRENTLY ONGOING. A SUPPLEMENTAL REPORT WILL BE SUBMITTED ONCE THE INVESTIGATION IS COMPLETE, AND THE RESULTS HAVE BEEN RECEIVED.