Experts say such implosions are extremely rare and don’t happen on their own. KING 5 investigators looked into what went wrong.
LONGVIEW, Wash. — A large industrial tank partially imploded at Japan’s Dynawave packaging and paper plant on Tuesday, killing at least two workers and releasing hundreds of gallons of corrosive chemicals that can dissolve skin on contact.
The facility uses storage tanks to convert wood chips into paper products, a process that relies on powerful, highly corrosive chemicals held under precise conditions.
The jar contains “white liquor,” a chemical mixture used to break down wood fibers into pulp. The chemical is so corrosive that experts tell KING 5 that tanks storing it often require special protective glass liners inside to prevent it from corroding the metal walls.
Unlike an explosion that pushes outward, an implosion means the tank violently collapses inward. Multiple experts who spoke to KING 5 said the occurrence is extremely rare and suggests a vacuum has formed inside the tank.
- What is an implosion? When the pressure inside a sealed tank is much lower than the outside air pressure, the outside atmosphere will squeeze the tank inward. Imagine drinking water from a plastic bottle until it collapses on itself—scale up to an industrial steel container filled with hundreds of gallons of corrosive liquid.
Experts explain that a vacuum does not create itself, which indicates there may be a problem involving the equipment, ventilation system, maintenance or shutdown procedures.
When a vacuum forms inside the tank, it causes the tank walls to buckle inward. This can cause the weld to fail, causing the contents of the tank to spill. The stronger the vacuum, the greater the buckling, the larger the hole in the weld, and the faster the contents can eject.
Experts explain that one possible scenario is that as liquid is pumped out of the tank, something may not be able to displace the internal pressure, causing the tank to rupture under the weight of the outside air.
In some cases, vacuums are also used to intentionally keep volatile chemicals cool, one expert said. If the valves, doors, or accessories on the tank cannot withstand these conditions, it may be sucked inside by the vacuum.
Experts say that when a tank collapses, the force can pull workers toward the tank and spray a stream of corrosive liquid outward. This chemical mixture is dangerous to any organic matter, including human skin. Experts say it can cause severe burns, dissolve muscle or cause death on contact.
Investigators with the Washington Bureau of Labor and Industries arrived on the scene shortly after the implosion and told KING 5 that a thorough investigation to determine exactly what happened could take weeks or months.
Cleaning up is not easy. One expert explained that the glass lining inside the tank may have been shattered and chemicals could have accumulated in the wreckage. Crews had to find a way to safely extract it and transport it elsewhere.
