Document OY566KnyynKJwRRpjm5wvQVK

/?u T'ys.e'&l ^ H. Waltemate J. W. Gressler Cleveland Pedricktown 11-20-7 HEAR MISS - REPETITIVE #7 "EXPLODING BOOBY TRAP" - BEDRICKTQWN On Tuesday, October 10, 1972, at approximately 3:30 p.ra. a Repetitive Accident Type #7 "Exploding Booby Trap" was experienced at the Pearl-Paste Polymerization Building (513). An explosion occurred within paste reactor_#26_, No injuries resulted: however, two roof panels and a roof ventilator above the-.reac.tQr were dislodged and a wall panel on the pearl side of the building was senarat&d pU.fifrLl3> A Board of Inquiry was held following the near miss, with the following in attendance: - Lead Technician H. T. Evans - Industrial Relations Manager J* W. Goetsch - Resin Manager G. E. Higby - Sr. Electrical Engineer - Technician - Technician - Technician J* M. Smith - Plant Engineer A. R. Webber - Plant Manager Facts Before tbe Incident Paste Polvmerizer #26 had gone through the normal sequence of events without incident. The reactor was put on transfer at 3:00 p.ra. and had finished the transfer and recovery phases by 3:20 p.ra. paste technician, opened the manhead and inserted a Crouse-Hinds type EVH 106 drop light into tbe_ reactor.. He then started flushing the reactor with_gLJ)_.M^ water hose. He had been flushing the reactor for approximately 5 minutes when he noticed water aDd_SQme___small chips setting QQ--the_bot tom of-frh* reactor. He called to the computer.console technician via the two-way radio, to find out if the sewer valve had been opened. The console technician replied that it had been opened. __________then went to the first floor to double_-_Gheck the position of the_Yarwav___YfrfctS.. While..' was, checking the Yarway the explosion took place. Facts at the Time of Che Incident lead technician, _ technicians, and a technician trainee, were on the Pearl side of the building when the explosion occurred. _ .* was inside poly #3, cleaning the reactor. All five employees heard the explosion but were not sure of the source. and stood by while got out of poly #3 technician put the building to "hold." had the computer redacted I NGC 15780 NEAR MISS - REPETITIVE #7 "EXPLODING BOOBY TRAP" PEDRICKTOWN Page 2 Facts at the Time of the Incident (Continued) ran from the first floorto the second floor, noticed an acrid odor, sounded the gas alarm and put on a Scott Air-Pak. * . went to their gas alarm stations complaining of a ringing sensationin his ears was sent to the Dispensary, i put on a Scott Air-Pak. wearing Scott Air-Paks, went to poly #26, installed an evacua tion hose, disconnected the drop light and checked the area. Both, \d , noted the hole in the roof, but saw no other physical damage. Facts Following the Incident The roof panels immediately above the poly were dislodged and a hole approximately 4* x 121 was opened in the roof. The roof ventilating fan above poly #26 was pushed upward from its base and the electrical conduit pulled loose. No evidence of a fire or explosive force was noted in the vessel; however some charring was present on the roof beams just above the reactor. The rupture disc, rated at 235 psi, was blown. The drop light fixture was blown out the roof and found 10 feet from the S.E. corner of the building. An investigation of the incident and a thorough check of the area was conducted by J. W, Goetsch, G. E. Higby, J. M. Smith, David Cawman, and H. T. Evans before the "all .clear" was. given at 3:45 p.in. The investigation and subsequent board of inquiry drew the following conclusions: flj Residual vinvl from the previous paste charge was ignited bv an electrical ^ snark. (2) The Crouse-Hinds EVH 106 drop light was not equipped with a supporting chain. The light cord was secured at the manhead with the full weight of the light fixture supported bv the cord. 3. The trainee, was tested and sustained no damage to his ears. 4. Poly #26 remained out of service until a thorough inspection and hydrostatic tests were conducted. 5. The manual vent line on poly #26 was slightly bent but did not require re placing. 6. Normal operations were resumed in the building at approximately 4:15 p.ra. 7. All employees responded to the emergencv calmly and efficiently. The employees in the building, especially were most effective. NGC 15781 NEAR MISS - REPETITIVE #7 "EXPLODING BOOBY TRAP" - PEDRICIdOWN Page 3 Additional Facts 1. The cause of the explosion is due to one of three possibilities: a* The light separated from the cord causing an arc, and the ensuing explosion. OR b. Water may have been accidentally sprayed on the hot globe causing it to crack thus causing a short and the ensuing explosion. OR c. The drop light may have slipped hitting the bottom of the reactor causing the globe to break, a short and the ensuing explosion. 2, All drop lights were equipped with supporting chains; however, the particular drop light involved did not have a supporting chain. The drop light was a low voltage. explosion-proof type but was not water proof. 4. The transformer did not short out and the breaker did not trip. According to the reason for the transformer not shorting or the breaker not tripping is that the cord was found with the wires separated and not touching. 5. Drop lights are inspected quarterly, however this particular drop light was two weeks past due. 6. Mr. W. E. Brodine was contacted and concurred with the inspection and test of the vessel. The vessel was entered, visually inspected and measured. No Variations were apparent. The agitator was removed to protect the oil seal during the hydrostatic test. The reactor was filled with water and pressured to 375 psi. The pressure was held for one hour with no noticeable loss of pressure. The vessel was hydrostatically tested according to ASME code. Corrective Action 1. All drop lights were removed from service immediately. 2. Explosion-proof hand lanterns have been purchased and are in use. Drop lights ordered in the future will be explosion proof and waterproof. The inspection of electrical cords and appliances was re-emphasized. NOC 15782 NEAR MISS - REPETITIVE #7 "EXPLODING BOOBY TRAP" - PEDRICKTOWN Corrective Action (Continued) The incident was reviewed with all employees. Page 4 JWG:rp J. W. Gressler cc D. L. Dowell - 0. F. Beckmeyer J* L. Nelson - R. D. Scott P. D. Terry E. W. Harrington W* E. Brodine G. Pow R. A. Kelley (Akron) Area Managers File Cl /-l * + ^ **-o C--F "Ft* /* o fv e? a i-Jo ^a fCl* y tJ ^ j; u / /. 4-4. c/ ^ a a * */, jTV r. ai<y & i* "4 * a^J' 0~+ +Ue~ At e A /-A c. At e ^cy *" 3 f- ? 3k NGC 15783