Kaiser Summary

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Kaiser Summary – Key points 
 
Technical Investigation Report available at: 
http://ncsp.tamu.edu/reports/MSHA/msha.htm#gi 
 
PD ~US$ 275 M – US$ 300 M 
 
BI ~ From July 5th to December 2010 with 100% production affected. From December 
2000 to March 2001 to reach 100% of new capacity. 
 
 
 Kaiser Alumina Refinery, Gramercy, LA 
 
 A 1999 explosion at the Kaiser Aluminum & Chemical Corporation (KACC) 
Alumina Refinery in Gramercy, LA destroyed substantial areas of the plant. 
Alumina production halted and extensive rebuild was necessary before 
production could resume. 
 
 Total capital cost of the rebuild and upgrade project to approximately $275 million 
from approximately $200 million (HOUSTON--(BUSINESS WIRE)--Dec. 14, 
2000). 
 
 Rebuilt included enhancement of plant capacity. 
 
 Event occurred in July 5, 1999. 
 
 Media in December 2000 indicated “plant is expected to progressively increase 
production over the next several weeks to approximately 75% of its newly rated 
capacity”. 
 Annual production capacity of the facility enhanced to 1.250 million metric tonnes 
after reconstruction. 
 The facility's annual capacity prior to the explosion was 1.070 million metric 
tonnes. 
 Construction of the final phase of the digestion unit was expected to be 
completed in March 2001. 
 
 
 
 
Summary of vessel data 
 
 
 
Highlighted vessels affected by explosion. Origin of explosion was possibly flash vessel 
6. 
 
 
Vessel Information (from Investigation report) 
 
 
Digestion Pressure Vessels 
The design criteria for the pressure vessels were obtained from original drawings 
prepared in 1958 by Chicago Bridge and Iron Company. The design criteria were based 
on 1956 Codes of the American Society of Mechanical Engineers. Design pressures are 
the maximum pressures allowed at the top of the vessel. 
 
Plate samples from each of the failed vessels were collected for metallurgical 
testing. The results indicated no defects. Test results are included as Appendix J. 
 
Thickness measurements were taken of the failed flash tanks and blow-off tank shell 
fragments. These measurements are contained in Appendix R. 
 
Desilicator 
The desilicator had a diameter of 11.5 feet, a height of 88 feet and a volume of 9,140 
cubic feet. The design temperature was 650ºF, and the maximum allowable working 
pressure (MAWP) was 600 PSIG. The pressure sensors on the desilicator had an upper 
limit of 700 PSIG. The desilicator was equipped with temperature transmitters with an 
upper limit of 550ºF. 
 
Digesters 
The four digesters were identified as V-1, V-2, V-3 and V-4. Digesters V-1, V-3 and V-4 
had a diameter of 11.5 feet, a height of 88 feet and a volume of 9,140 cubic feet. Their 
design temperature was 650ºF, and their MAWP was 600 PSIG. 
 
Digester V-2 had a diameter of 15.6 feet, a height of 127.6 feet and a volume of 24,388 
cubic feet. The design temperature was 600ºF, and the MAWP was 600 PSIG. 
 
The pressure sensors on all four digesters had an upper limit of 700 PSIG. Each 
digester was equipped with temperature transmitters with an upper limit of 500ºF. 
 
Flash Tanks 
Temperature sensors were not provided for the flash tanks. Each flash tank was 
equipped with pressure sensors. 
 
Kaiser documents indicate the following relief valve settings for the flash tanks: Flash 
Tank Nos. 1 through 3, 457 PSIG; Flash Tank No. 4, 220 PSIG; Flash Tank Nos. 5 and 
6, 136 PSIG; Flash Tank Nos. 7 through 9, 47 PSIG. 
 
Flash Tank Nos. 1, 2 and 3 each had a diameter of 10 feet, a height of 42.1 feet, and a 
total volume of 2,880 cubic feet. Each of the three tanks was equipped with pressure 
sensors with an upper limit of 500 PSIG. The MAWP was 457 PSIG. 
 
Flash Tank No. 4 had a diameter of 15 feet and a height of 42.4 feet, with a total volume 
of 6,185 cubic feet. Tank No. 4 was equipped with pressure sensors with an upper limit 
of 300 PSIG. Tank No. 4's MAWP was 220 PSIG. Flash Tank Nos. 5 and 6 each had a 
diameter of 15 feet, a height of 42.4 feet, and a volume of 6,185 cubic feet. Flash Tank 
No. 5 was equipped with pressure sensors with an upper limit of 200 PSIG. Flash Tank 
No. 6 was equipped with pressure sensors with an upper limit of 150 PSIG. Flash Tank 
Nos. 5 and 6 were rerated in 1990 to allow Kaiser to raise their MAWP to 156 PSIG. 
 
Flash Tank No. 7 had a diameter of 15 feet, a height of 38.8 feet, and a volume of 5,183 
cubic feet. It was equipped with pressure sensors with an upper limit of 120 PSIG. The 
MAWP of Tank No. 7 was 47 PSIG. 
 
Flash Tank Nos. 8 and 9 each had a diameter of 18 feet, a height of 42 feet, and a 
volume of 6,922 cubic feet. Flash Tank No. 8 was equipped with pressure sensors with 
an upper limit of 60 PSIG. Flash Tank No. 9 was equipped with pressure sensors with 
an upper limit of 30 PSIG. The MAWP of each tank was 47 PSIG. 
 
Blow-Off Tank 
The blow-off tank was designed according to the American Petroleum Institute Code for 
Large Low Pressure Storage Tanks. The blow-off tank had a diameter of 18 feet, a 
height of 40 feet, and a volume of 6,922 cubic feet. The blow-off tank's design pressure 
was 5 PSIG with a design temperature of 237ºF. The tank was equipped with a 
temperature transmitter with an upper limit of 300ºF. 
 
Relief Tank 
The relief tank was a non-pressurized vessel with a louvered top, and had a volume of 
18,320 cubic feet. The tank was not provided with pressure or temperature sensors.