Lesson Learned Statement:Improper material selection caused a nitric acid leak, interrupted process operations, and created a personnel safety and health hazard.Discussion:On December 15, 1997, at the Savannah River Site H-Canyon, approximately 2 gallons of acid leaked from a tank automatic inlet valve soon after operations personnel performed a valve line-up to transfer acid between two tanks. Facility personnel noticed the leak and reported it to control room personnel. They immediately contacted radiation control and industrial hygiene personnel to determine the appropriate response and personal protection requirements. The radiation control officer required personnel in the immediate area of the spill to wear respiratory protection until the spill was cleaned up. Operations personnel washed the spill area with water until acid concentrations were reduced to zero parts per million. Investigators determined that the leaking valve, made of carbon steel, had been corroded through by the 50 percent nitric acid in less than a month. Improper material selection caused a nitric acid leak, interrupted process operations, and created a personnel safety and health hazard. (ORPS Report SR--WSRC-HCAN-1997-0053) Investigators determined that maintenance mechanics recently replaced the automatic inlet valve with a carbon steel valve. They also determined that the mechanics installed the valve in accordance with workbook instructions. The valve is "general services not authorization basis related" equipment. During a critique, the first line supervisor said that he inadvertently ordered the wrong valve. Investigators also determined that the two maintenance mechanics who shop-checked and installed the valve failed to recognize that the wrong valve had been procured. Long-term corrective actions are being developed. Immediate actions included the following. * The facility manager stopped all 50 percent nitric acid transfers until the valve is replaced. * The facility manager issued a shift order requiring the shift technical engineer to verify that the correct material is installed in any hazardous system. * Separations maintenance personnel performed a visual walk-down of acid valves to confirm that the remaining valves are stainless steel. A search of the ORPS database for similar occurrences found 11 reports that involved corrosion because of improper material selection. Occurrences resulting from improper material selection are uncommon and there appeared to be no common trend. For the occurrences reported, the operating environment either changed with time or was not identified. In all cases, the failed, corroded materials were replaced with materials more suited to their operating environment.Analysis:N/ARecommended Actions:These events highlight the importance of proper material selection. Even in systems that are not authorization basis related, and where less rigorous procurement, testing, and inspecting requirements apply, improper material selection can have severe environmental, safety, and health consequences. DOE 5700.6C, Quality Assurance, specifies criteria for procurement and acceptance testing. These criteria discuss controls for selection and determination of suitability of purchased items.Originator:DOE Operating Experience Weekly Report 97-53Validator:N/AContact:N/AName Of Authorized Derivative Classifier:n/aName Of Reviewing Official:Priority Descriptor:Blue / InformationKeywords:ACID, CORROSION, MATERIAL COMPATIBILITY, PROCUREMENT, 5700.6AReferences:DOE OE Weekly Summary 97-53 URL http://tis-hq.eh.doe.gov:80/web/oeaf/oe_weekly/oe_weekly_97/oe97-53.html ORPS Report SR--WSRC-HCAN-1997-0053Information in this report is accurate to the best of our knowledge. As means of measuring the effectiveness of this report please use the "Comment" link at the bottom of this page to notify the Lessons Learned Web Site Administrator of any action taken as a result of this report or of any technical inaccuracies you find. Your feedback is important and appreciated. DOE Function / Work Categories:QualityTraining & Qualifications ISM Category:Hazard:Environmental ReleasePersonal Injury / Exposure - Hazardous Material (General)
|
||||||||
|
|| Home | Lessons Learned | SELLS | Listserv | Submit Lesson || || Documents and Information | Links | Contacts | Security Notice | Comments || |