Describe what happened?

Whilst adding liquid nitrogen to a dewar with a glass insert, liquid nitrogen entered between the glass insert and outer casing via a gap in the seal, causing implosion of the dewar. The majority of the glass stayed inside the vessel and the remainder was cleaned up with a dust pan and brush, and disposed of.

What were the immediate cause(s)?

Dewar explosion.

What were the root cause(s)?

Defective equipment.

Describe the action taken

Discussed with Facility Manager and user involved. The particular vessel was supplied with the EM and is of a particular size. This was the oldest vessel of its type used, and all others are in good condition, however I recommend regular checks of the seals are implemented, and the supplier of the vessels informed. A safety notice regarding the risk of implosion/explosion of dewars with faulty seals has been sent to the Faculty, and regular checks of a similar design recommended.

Images (optional)


IN015086 - dewar implosion