Disclaimer: The Lessons Learned Database includes the incidents that were voluntarily submitted. The database is not a comprehensive source for all incidents that have occurred.
The risk of a serious fire occurring inside the chemistry laboratory hood from use of hydrogen gas and/or presence of a small quantity of hydrazine-hydrate was underestimated. Additional control measures were required to reduce the risk of fire…
All safety devices worked as designed thereby protecting the environment and laboratory personnel. Researchers involved in the experiment acted properly and with the parameters set forth in operational procedures.
Follow up: Stops have…
Whenever a new program or organization is created, management should ensure that program interfaces and new responsibilities are clearly defined. Effective program integration is necessary to ensure that all responsibilities and requirements are…
Procedures will be revised to include specific information about hydrogen sensors and alarm controls. Caution will be added about sparks and flames in the fuel cell operation area. Workers will be cautioned that shunt resistors may reach high…
Management should ensure that a complete and thorough review of the previous work activities identified in the work package is performed at the pre-job briefing for the planned work. Work activities should be discontinued if any confusion exists…
This occurrence demonstrated the use of data by engineering to evaluate equipment problems. As the data changed, highlighting a problem with one-half inch PVC ball valves, the facility redesigned the valve extension and valve handle to prevent…
This occurrence highlights the need for ensuring work is organized and planned in a manner that is practical and efficient. The primary lesson learned from this occurrence is that personnel must be cognizant of the impact of their actions on…
The manager in charge acknowledged that, while he made relatively recent modifications to the high-pressure gas storage side of the system and had directed a major rebuilding of various units, the moderate-pressure interconnecting system (the…
This incident occurred due to moisture in the sample line monitoring system. Removing moisture from the sample line increases the reliability of the equipment. Further evaluations are being considered for improving system reliability.
Although most of the hydrogen fluoride piping system was open to the atmosphere before the elbow was cut, the lines were not purged. Two plugs of residual material on either side of the elbow remained in place, thus allowing hydrogen to be…
Follow-up investigation of this occurrence confirms that it was inadvertent. Attention to detail while performing any task is a must for all personnel. This is to insure the safety of both the individual performing the task and others that may…
Work pre-planning is essential whenever maintenance or work activities may have an adverse impact on everyday operations. When there are changes to the operational status of any critical system, especially a safety critical system, those changes…
In any event, the lesson that should be derived from this incident is the fact that the explosion could have been avoided either by using an inert gas instead of air across the diaphragm, or by monitoring the hydrogen concentration in the upper…
As demonstrated by the fire discussed above, lack of adequate maintenance, system monitoring and oversight of maintenance of these facilities can contribute to the ignition of a fire that is difficult to extinguish and poses an extreme danger to…
This incident illustrates how a hydrogen fire which appears to be 'quite small' can actually be only the visible portion of a much larger fire. Observation alone is not a reliable technique for detecting pure hydrogen fires and/or assessing their…
An important lesson to be derived from this incident is the need to carefully engineer and test all repairs and modifications to high-pressure process equipment.
This incident illustrates how difficult it is to completely purge hydrogen out of a large, complex piece of equipment. Uniform mixing and dilution is unlikely in all the partially enclosed spaces, crevices, etc. If a hazardous operation such as…
This incident illustrates the danger of hydrogen being inadvertently released through blown water seals. Similar incidents have occurred in non-nuclear industrial facilities, but offgas systems present a special hazard because of the…
The mechanisms and rates by which hydrogen gas is generated and subsequently accumulated in the holding tank need to be fully understood by vendors and employees alike. Active venting, warning signs, and local alarms designed to activate when…
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