image of a hydrogen fuel cell

H2Incidents: Hydrogen Incident Reporting and Lessons Learned

About H2Incidents | Advanced Search

H2Incidents Help!

Definitions

Incident
An incident is an event that results in:
  • a lost-time accident and/or injury to personnel
  • damage to project equipment, facilities or property
  • impact to the public or environment
  • an emergency response or should have resulted in an emergency response.
Near-Miss
A near-miss is an event that, under slightly different circumstances, could have become an incident. Examples include:
  • any unintentional hydrogen release that ignites, or is sufficient to sustain a flame if ignited, and does not fit the definition for an incident
  • any hydrogen release which accumulates above 25% of the lower flammability limits within an enclosed space and does not fit the definition of an incident
Non-Event
A non-event is a situation, occurrence, or other outcome relevant to safety that does not involve a particular incident or near miss. For example, a non-event might consist of a failed safety inspection.
Close

H2Incidents Help!

Navigation

The left navigation on the H2Incidents website is two-fold.

  1. Links
    By clicking on the links in the left navigation, you can view all incident reports matching that lone selection. For example, clicking on "Minor Injury" within the "Damages and Injuries" category will return a list of all incident reports that included "Minor Injury."
  2. Checkboxes
    Selecting checkboxes next to navigation items—then clicking the "Update Criteria" button—will provide a restrictive search on the criteria selected. Each selected checkbox will restrict the results to only incident reports that include that criteria. For example, selecting the checkbox next to "Minor Injury" in the "Damages and Injuries" category and selecting the checkbox next to "Decision Making" in the "Factors" category will return a list of all incident reports that included both "Minor Injury" and "Decision Making."
Close

Incident Report

Ignition of Syngas Leak from Ammonia Production Plant

Incident Date: 2006

 

Severity:
Incident

Was Hydrogen released?
Yes

Was there Ignition?
Yes

Ignition Source: self-ignition

Description

During restart of an ammonia production plant, syngas (50% hydrogen mixed with methane, ammonia, and nitrogen) leaking from a flange directly downstream of the synthesis reactor ignited. The plant had been shut down for about 90 minutes due to a technical problem. Alerted by the plant fire alarm, the operator activated the emergency shutdown, which isolated and depressurized the synthesis loop. Steam was sprayed onto the leak site to dampen the fire, which was brought under control 55 minutes later. Property damages included pipe insulation, the reactor's protective shutters, concrete fireproofing of the reactor structure, and instrumentation cables within 3 meters of the leak site. The flames did not affect the synthesis reactor itself, which was protected by a deflector. The incident was caused by inappropriate tightening torque applied to the bolts of the leaking flange, which was not adapted to the exceptional operating conditions when the incident occurred (i.e., a large temperature difference between the bolts and the flange due to the relatively short shutdown period).

Setting

Equipment

Piping/Fittings/Valves

Damage and Injuries

Probable Cause(s)

Contributing Factors

Characteristics

The incident was discovered During Operations.

Lessons Learned/Suggestions for Avoidance/Mitigation Steps Taken

The incident was the result of a combination of factors leading to exceptional temperature conditions that were not taken into account in the mechanical design of the reactor. Corrective actions that were implemented by the plant management included:

· redefinition of the appropriate tightening torque on flanges
· improved design of the leak collector on the flange (which failed during the accident)
· creation of a nitrogen injection system in the leak collector
· installation of a steam-injection system to protect the bottom part of the synthesis reactor.

Date Added to H2Incidents: 3/30/2012