GENERAL44929 - Laserfiche WebLink

Home Browse Search

I ER`~ CORRESPONDENCE LF 709 FROM Mark A. Robinson TD Irv Nash AT Denver AT Edna Mine III III III III IIII III IN REPLY REPER TO p-0301.15 DATE 21-Jul-81 SUBJECT: REMOVAL OF PCB AND PCB-CONTAMINATED DIELECTRIC FLUID FROM EDNA MINE During the week of July 6 work was completed to remove approximately 150 gallons of PCB and PCB-contaminated dielectric fluid from Edna Mine. The work was performed by the Denver General Electric ( G. E. ) Service Shop. Approximately 141 gallons of the total oil removed was in three (3) PCB transformers that were disposed of. Nine (g) gallons of PCB-contaminated oil was removed from one oil circuit breaker (OCB), Type E124A, located on the 1260W dragline. In addition, nine (g) gallons of non-PCB oil was removed from another OCB, Type E124A, also located on the 1260W dragline. Both OCB's were flushed with a quality cleaning solvent (Chlorothene Nu) and filled with General Electric 10-C oil. No spillage of hazardous liquid occurred during this work. In addition to the removal of this hazardous liquid, several transformers which had developed leaks were repaired. Two 100KVA (13.2KV - 480V) transformers, one PCB and the other PCB-contaminated, located in the fantail of the 1260W drag- line, had developed cracks in the bottom of the tanks. The cracks were due to the method by which the transformers were mounted. After several attempts to repair the transformers in place, it was decided the transformers should be removed and repaired in G. E.'s Denver shop. One transformer was removed and sent to Denver to be repaired. To keep downtime of the 1260W to a minimum, a spare 100KVA transformer was installed in its place. The repaired transformer was returned the following day and installed in the place of the second leaking PCB transformer. This transformer was then sent to Denver for repairs. A third 100KVA transformer (non-PCB) located in the fantail was found to have a very bad leak in the bottom of the tank. Since this transformer was not covered in the original contract with G. E., a $1,000 adder was to be charged for its repair. A decision was made to repair this transformer at the mine shop instead of accepting the $1,000 charge. The non-PCB transformer was then changed out with the repaired PCB transformer (with the help of G. E.) and repaired. This transformer will now be used as a spare. Both the PCB and PCB-contaminated transformers were flushed with Chlorothene Nu and filled with 10-C oil. Oil samples were taken from both trans- formers and the PCB-contaminated OCB. The test results and labels will be forwarded upon receipt. All other PCB and PCB-contaminated transformers which were leaking were repaired without incident.