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Author
Alvares, N. J.
Title
Assessment of Extent and Degree of Thermal Damage to Polymeric Materials in the Three Mile Island Unit 2 Reactor Building. Volume 6.
Coporate
Lawrence Livermore National Lab., Livermore, CA
Sponsor
EG and G Idaho, Inc. Department of Energy, Three Mile Island, PA
Report
GEND-INF--023-Vol. 6; DE84-010031, February 1984, 59 p.
Contract
W-7405-ENG-48 DE-A007-76ID01570
Book or Conf
International Association for Fire Safety Science. Fire Safety Science. Proceedings. 1st International Symposium October 7-11, 1985, Hemisphere Publishing Corp., New York, Gaithersburg, MD, Grant, C. E.; Pagni, P. J., Editors, 647-656 p., 1986
Keywords
polymers | nuclear power plants
Abstract
Thermal damage to susceptible materials in accessible regions of the TMI-2 reactor building shows damage-distribution patterns that indicate non-uniform intensity of exposure. No clear explanation for non-uniformity is found in existing evidence; e.g., in some regions a lack of thermally susceptible materials frustrates analysis. Elsewhere, burned materials are present next to materials that seem similar but appear unscathed--leading to conjecture that the latter materials preferentially absorb water vapor during periods of high local steam concentration. Most of the polar crane pendent shows heavy burns on one half of its circumferential surface. This evidence suggests that the polar crane pendant side that experienced heaviest burn damage was exposed to intense radiant energy from a transient fire plume in the reactor containment volume. Tests and simple heat-transfer calculations based on pressure and temperature records from the accident show that the atmosphere inside the reactor building was probably 8% hydrogen in air, a value not inconsistent with the extent of burn damage. Burn-pattern geography indicates uniform thermal exposure in the dome volume to the 406-ft level (about 6 ft below the polar crane girder), partial thermal exposure in the volume between the 406- and 347-ft levels as indicated by the polar crane cable, and lack of damage to most thermally susceptible materials in the west quadrant of the reactor building; some evidence of thermal exposure is seen in the free volume between the 305- and 347-ft levles.