Hydrogen and water leakage in the main generator stator cooling water (SCW) equipment forced two separate shutdowns of a nuclear plant in a three-month period. Manufacturer weld defects on the SCW exciter end ring header are the likely cause for the hydrogen leakage.

The first nuclear plant shutdown was initiated in mid-May when an SCW leak internal to the main generator was confirmed. Events that led up to the shutdown decision started three days earlier and included an upward trend in stator coil temperatures. After two days of an elevated temperature trend, an SCW tank high-pressure alarm indicated hydrogen leakage. Per alarm response procedure, the operators vented the tank. Hydrogen leakage was determined to have increased from about 300 to 1400 ft3/day with stator water view more

On July 1, 2009, a plasma experiment was conducted to produce a small quantity of sodium borohydride from anhydrous sodium borate, methane, and hydrogen in an enclosed reaction chamber. The reactants were injected into an argon plasma flame to carry out the synthesis reaction.

After the run was completed, as per work control procedure, the experimenter removed the plasma torch from the top lid of the collection chamber and taped a piece of weighing paper over the opening so air would not get into the chamber and contaminate the product. The experimenter then installed a plastic glove bag over the top lid of the collection chamber and attached it just below the top lid using Velcro. Before final installation, the experimenter placed a screwdriver and a natural bristle paint brush view more

A hydrogen leak occurred from a 1-inch gate valve on a makeup gas line in an oil refinery gas oil hydrotreater unit. When the leak was discovered, the gas oil hydrotreater unit shutdown procedures were immediately implemented and emergency response was requested. The refinery response team along with county response teams responded, and after approximately 1/2 hour, the gas oil hydrotreater unit was fully shut down. Shutdown consisted of sufficiently depressurizing the unit and adding nitrogen to allow safe closing of the leaking 1-inch gate valve and installation of the associated missing bull plug.

During this event, the 1-inch gate valve was found to be open roughly 10% with no bull plug in the valve, allowing the hydrogen to leak to the atmosphere. In addition, a 1-inch bull view more

An instrument engineer at a hydrogen production facility was arresting the hydrogen leakage in tapping a pressure transmitter containing 131-bar hydrogen gas. The isolation valve was closed and the fittings near the pressure transmitter were loosened. The pressure dropped from 131 bar to 51 bar. The fitting was further loosened (though very little); the instrument tube slipped out of the ferrule and got pulled out of the fitting. With the sudden release of the 51-bar hydrogen, there was a loud pop (like a fire cracker) and the spark-proof tool was observed to have black spot on it. The volume of the hydrogen gas released was small, since it was in the tapping line only.

A small research sample of approximately 5 grams of aluminum hydride (alane) doped with 2-3 mol % TiCl3 contained within a glass ampoule ruptured after transit while stored in an office cabinet. The rupture was attributed to over-pressurization caused by hydrogen gas buildup within the sample over a four-month period. The glass ampoule, contained within a 0.2-inch thick cardboard shipping tube, was not a pressure-rated container. The rupture resulted in glass chards penetrating the protective cardboard shipping tube. The aluminum hydride, a fine powder, was released from the shipping tube during the pressure release. The fine aluminum powder leaked from the cabinet and set off a local smoke alarm that brought emergency responders to the scene. No personnel were present in the area when view more

A student cleaned catalyst that was being used for a fuel cell membrane electrode assembly from a spatula. He then placed the contaminated paper towel into a waste container that contained other waste that was wet with alcohol. The alcohol reacted with the catalyst, igniting a fire within the waste container. The fire was extinguished with a beaker of water.

An explosion occurred within the hydrogen processing system of a chemical plant that produces sodium chlorate for bleaching pulp and paper. The chemical process utilizes electrolytic cells and is pH-dependent. Hydrogen is produced as a byproduct and is utilized as a fuel.

At the time of the incident, the plant was at an abnormal operating level of 25% capacity. A non-routine maintenance operation to repair high-pH liquid piping was in progress. To assist, operations personnel rerouted the high-pH liquid stream to the plant sump. However, in doing this, the liquid eventually made its way back into the electrolytic process by design. Ultimately this created the root cause of the explosive condition in that the pH of the electrolytic process increased faster than the computer- view more

A hydrogen leak and subsequent explosion occurred when tie-downs on a hydrogen transport trailer securing hydrogen cylinder packages failed. The tie-down failure caused the hydrogen cylinder packages to fall off the trailer and eject some cylinders onto the roadway (see Figure 1). The cause of the accident is unknown, but it appears to be unrelated to hydrogen (i.e., likely tie-down strap weakness or error in properly securing tie-downs). The cylinders contained compressed hydrogen gas at 200 bar (2900 psi). The accident caused some hydrogen cylinders to leak and the associated cylinder package plumbing systems were breached. A spark or other local heat source (e.g., from a nearby vehicle motor) ignited the leaking hydrogen and caused a deflagration/explosion that damaged a car view more

A hydrogen leak occurred when hydrogen tube trailer traveling on a rural roadway left the road, overturned on its side, and resulted in a single hydrogen tube valve being opened or broken. The cause of the accident is unknown, however, it appears to be unrelated to hydrogen (i.e., it is likely that human driving errors caused the accident). The hydrogen tubes contained compressed hydrogen gas at 200 bar (2,900 psi). The back end of the tube trailer containing the high-pressure hydrogen plumbing and valves contacted the ground and resulted in the valve opening or breaking and losing all the hydrogen from one tube. The tube/valve that leaked was located on the bottom tier in the center position. The first firefighter crew to arrive at the accident scene verified that the leakage was view more

A hydrogen fire occurred in an early morning accident involving a hydrogen tube trailer and multiple vehicles on a rural highway. The cause of the collision is unknown, however, it appears to be unrelated to hydrogen (i.e., it was likely human driving errors). The hydrogen tubes contained compressed hydrogen gas at a pressure of 15 bar (218 psi). The accident caused a leak in the hydrogen plumbing system and deformed one of the hydrogen tubes, resulting in a 10-centimeter (4-inch) longitudinal crack from which hydrogen began to leak (see Figures 1 and 2). Fire from the conventional vehicles trapped under the hydrogen tube trailer during the accident ignited combustible components on the tube trailer (tires and fuel/oil), and subsequently the leaking hydrogen. Emergency crews arrived view more