At least two employees have died and nine others are presumed dead after a white liquor tank collapsed at the Nippon Dynawave Packaging paper mill in Longview, Washington. The accident occurred at around 7 a.m. on May 26, confirms Japanese parent company Nippon Paper Industries.
According to the Associated Press the tank could hold approximately 900âeuros000Â gallons, or nearly 3400Â m 3 . More than half full at the time of the rupture, it would have released more than 500âeuros000Â gallons of white liquor onto the site, or about 1âeuros900Â m 3 or 1.9 million liters.
Used in the kraft process to cook wood chips and dissociate lignin and hemicellulose from cellulose, this solution is notably composed of caustic soda (or sodium hydroxide) and sodium sulfide.
Rescuers were confronted with a particularly unstable situation. Local media OPB reports that search operations were initially suspended due to the risk of the tank collapsing again. According to CBS News the authorities then revised downwards the volume remaining in the equipment: approximately 25âeuros000Â gallons, or nearly 95Â m 3 this means that access to certain areas remains conditional on stabilization of the structure, control of run-off and protection of workers against caustic products. Access to certain areas is therefore subject to stabilization of the structure, control of runoff and protection of workers from caustic products.
Highly corrosive, the white liquor made the intervention particularly delicate, due to the risk of burns, splashes and inhalation. Several casualties were treated for chemical burns and respiratory injuries.
Environmental issues are monitored. L' Associated Press indicates that some of the product reached drainage ditches and then the Columbia River. However, authorities had not observed any impact on the river at the time of the latest available information.
In a press release, Nippon Paper Industries, which owns the site, refers for the time being to "multiple victims and indicated that the effects on the environment and production were still being assessed.
Every year, the plant produces around 280âeuros000Â tonnes of bleached board (NBSK) for liquid packaging (equivalent to six billion one-liter milk cartons), as well as merchant paper pulp for a wide variety of applications (tissues, printing paper, chewing gum wrappers, tea filtration paper, gift wrap). The plant employs around 1,000 people.
