What is Lessons Learned?

What is H2LL?

This database is supported by the U.S. Department of Energy. The safety event records have been contributed by a variety of global sources, including industrial, government and academic facilities.

H2LL is a database-driven website intended to facilitate the sharing of lessons learned and other relevant information gained from actual experiences using and working with hydrogen. The database also serves as a voluntary reporting tool for capturing records of events involving either hydrogen or hydrogen-related technologies.

The focus of the database is on characterization of hydrogen-related incidents and near-misses, and ensuing lessons learned from those events. All identifying information, including names of companies or organizations, locations, and the like, is removed to ensure confidentiality and to encourage the unconstrained future reporting of events as they occur.

The intended audience for this website is anyone who is involved in any aspect of hydrogen use. The existing safety event records are mainly focused on laboratory settings that offer valuable insights into the safe use of hydrogen in energy applications and R&D. It is hoped that users will come to this website both to learn valuable lessons from the experiences of others as well as to share information from their own experiences. Improved safety awareness benefits all.

Development of the database has been primarily supported by the U.S. Department of Energy. While every effort is made to verify the accuracy of information contained herein, no guarantee is expressed or implied with respect to the completeness, causal attribution, or suggested remedial measures for avoiding future events of a similar nature. The contents of this database are presented for informational purposes only. Design of any energy system should always be developed in close consultation with safety experts familiar with the particulars of the specific application.

We encourage you to browse through the safety event records on the website and send us your comments and suggestions. We will continue to add new records as they become available.

How does H2LL work?

If you have an incident you would like to include in the H2LL database, please click the "Submit an Incident" button at the top of the page. You will be asked for a wide range of information on your incident. Please enter as much of the information as possible. In order to protect your and your employer's identities, information that may distinguish an incident (your contact information, your company's name, the location of the incident, etc.) will not be displayed in the incident reports on H2LL.

Lessons Learned Corner

Visit the Lessons Learned Corner Archives.

Key themes from the H2Incidents database will be presented in the Lessons Learned Corner. Safety event records will be highlighted to illustrate the relevant lessons learned. Please let us know what you think and what themes you would like to see highlighted in this safety knowledge corner. You can find all the previous topics in the archives.

A petroleum refinery experienced a catastrophic rupture at one bank of three heat exchangers in a catalytic reformer/naphtha hydrotreater unit because of high temperature hydrogen attack (HTHA). Hydrogen and naphtha at more than 500F were released from the ruptured heat exchanger and ignited, causing an explosion and an intense fire burned for more than three hours.

The rupture fatally injured seven employees working in the immediate vicinity of heat exchanger at the time of the incident. The workers were in the final stages of a start-up activity to put a parallel bank of three heat exchangers back in service following cleaning. Such start-up activities had resulted in frequent leaks and occasional fires in the past and should have been considered as hazardous and nonroutine. view more

Spent platinum catalyst is recovered from corrugated stainless steel by chemical stripping and recovery. The process is completed by placing the material in lined tanks filled with hydrochloric acid (HCl). Approximately 500 pounds of corrugated stainless steel with platinum coating was inserted into a HCl leaching bath. Prior to starting the process, the supervisor tested the material for reactivity for a period of one hour, and the material showed very little reactivity. Operators began setting up three 500-gallon tanks, each containing the corrugated material. The material was covered with water and 4-5 inches of HCl was then added to the tank. When all three tanks were set up and there was only minimal reactivity observed (occasional bubbles), the operators left the area.

An view more

Hydrogen was released near the ground when the vent line from a 13,000-gallon liquid hydrogen storage vessel suffered damage from unusually high winds. The toppled vent line did not shear or tear, but sustained a kink that restricted hydrogen flow and created a back pressure on the vessel relief system.

Repair efforts were hampered by the potential for cold hydrogen gas, a flammability hazard, in the work area. Shut off or redirection of the hydrogen was not possible, and variable breezes made set up of safe zones uncertain. A protocol had not been prepared for this scenario.

 

Near the end of the process of filling a gaseous hydrogen tube trailer at a liquid hydrogen transfilling station, a safety pressure-relief device (PRD) rupture disc on one of the tube trailer’s ten tubes burst and vented hydrogen gas. The PRD vent tube directed gas to the top of the trailer where the hydrogen vented and ignited, blowing a flame straight up in the air. The operator filling the tube trailer heard a loud explosion from the sudden release of hydrogen gas and saw flames immediately. The operator closed the main fill valve on the tube trailer, stopping the hydrogen fill; however, the ten cylinders on the tube trailer were almost full (2500 psig/173 bar). The tube trailer involved in this incident was one of two tube trailers being filled simultaneously and was second in a view more

During normal operations, a two-inch flame was discovered emanating from a pinhole leak in a hydrogen line at an aircraft parts manufacturing facility. Hydrogen was not in use by any process in the facility at the time. The flame was discovered by a contractor who was about to start welding on scaffolding about 3-5 feet away. Before starting, the welder searched the immediate area for any signs of fire per his training. When he spotted the flame, he called his supervisor.

An operator tried to put out the fire with a fire extinguisher, which resulted in the flame enlarging by one inch. All employees and contractors were instructed to leave the area, and the EHS team leader called 911 and informed the fire department that there was a hydrogen fire at the facility. She then put an view more

An explosion at a coal-fired power plant killed one person and injured 10 others. The blast killed the delivery truck driver who was unloading compressed hydrogen gas, which is used to cool the plant's steam generators. Hydrogen deliveries are routine at the plant, occurring about once a week. Evidence pointed to the premature failure of a pressure-relief device (PRD) rupture disk, which had been repaired by the vendor six months prior to the explosion.

Overview

The catalyst in a dehydrogenation reactor, which was usually operated under a hydrogen atmosphere, was changed while the reactor was isolated from the peripheral equipment by closing a 20-inch remotely controlled valve. The hydrogen pressure in the peripheral equipment was set at 20 KPaG, and the reactor was opened to the atmosphere. Anticipating some hydrogen leakage, suction from the piping was accomplished with a vacuum device and, nitrogen sealing was performed. When the piping connections were restored after changing the catalyst, flames spouted from the flange clearance and two workers were burned. One cause of the fire was poor management of the catalyst replacement process.

Incident Synopsis

A catalyst exchange was carried out in a dehydrogenation view more

Overview

Hydrogen leaked from the outlet piping of a hydrogen heating furnace at a fuel oil desulfurization cracking unit during normal refinery operation. The leaking hydrogen caused a localized fire. Dilution water for cleaning polythionic acid collected in the drain nozzle after a turnaround shutdown. The chlorine concentration in this dilution water was high because its concentration in the industrial water was originally high. The chlorine in the industrial water was concentrated by the high temperature, after the plant was restarted, and stress corrosion cracking occurred. Hydrogen leaked and was ignited by static electricity or heat.

Incident 

A fire occurred at the fuel oil desulfurization cracking unit of a refinery 257 hours after startup of the plant, view more

Overview
During operation of a succinic acid plant, hydrogen leaked from a mounting joint on a safety valve at the upper part of a reactor, which generated a hydrogen flame. Prior to the incident, the safety valve was removed and reattached during an inspection at a turnaround shutdown. An incorrectly sized, smaller gasket was installed on the joint, and the tightening force on the bolts was inadequate. Therefore, a gap was generated as time went by and un-reacted hydrogen leaked.

Background
In the case of many leak tests after construction, a leak is checked by a soap test after pressurizing piping and facilities for the test. (A soap test is conducted by pouring soap suds at the place to be checked (mainly a joint part) after pressurizing. If bubbles are found, view more

Overview
A hydrogen leak and fire occurred due to the installation of an incorrectly sized gasket at a solvent manufacturing plant. A worn gasket was accidentally replaced with a new gasket that was smaller than the standard one, and the system could not withstand the operational pressure of the hydrogen, causing the hydrogen to leak and ignite a small fire. Furthermore, a nearby gasket was damaged by the fire, causing a larger quantity of hydrogen to leak, and the fire spread. As nitrogen was substituted for the combustible hydrogen gas in the piping at an early stage of the fire, damage was limited to the immediate area. If the hydrogen had not been quickly purged from the system, the fire damage would have been greater. It is assumed that gasket management at a turnaround view more