Degradation of HEPA filters exposed to DMSO
Dimethyl sulfoxide (DMSO) sprays are being used to remove the high explosive (HE) from nuclear weapons in the process of their dismantlement. A boxed 50 cfm HEPA filter with an integral prefilter was exposed to DMSO vapor and aerosols that were generated by a spray nozzle to simulate conditions expected in the HE dissolution operation. After 198 hours of operation, the pressure drop of the filter had increased from 1.15 inches to 2.85 inches, and the efficiency for 0.3 {mu}m dioctyl sebacate (DOS) aerosols decreased from 99.992% to 98.6%. Most of the DMSO aerosols had collected as a liquid pool inside the boxed HEPA. The liquid was blown out of the filter exit with 100 cfm air flow at the end of the test. Since the filter still met the minimum allowed efficiency of 99.97% after 166 hours of exposure, we recommend replacing the filter every 160 hours of operation or sooner if the pressure drop increases by 50%. Examination of the filter showed that visible cracks appeared at the joints of the wooden frame and a portion of the sealant had pulled away from the frame. Since all of the DMSO will be trapped in the first HEPA filter, the second HEPA filter should not suffer from DMSO degradation. Thus the combined efficiency for the first filter (98.6%) and the second filter (99.97%) is 99.99996% for 0.3{mu}m particles. If the first filter is replaced prior to its degradation, each of the filters will have 99.97% efficiency, and the combined efficiency will be 99.999991%. The collection efficiency for DMSO/HE aerosols will be much higher because the particle size is much greater.
- Research Organization:
- Lawrence Livermore National Lab., CA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 10176644
- Report Number(s):
- UCRL-JC-115889; CONF-940738-7; ON: DE94017411; TRN: 94:018802
- Resource Relation:
- Conference: 23. DOE/NRC nuclear air cleaning and treatment conference,Buffalo, NY (United States),25-28 Jul 1994; Other Information: PBD: 11 Jul 1994
- Country of Publication:
- United States
- Language:
- English
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Development of an air cleaning system for dissolving high explosives from nuclear warheads
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Related Subjects
45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE
DMSO
CORROSIVE EFFECTS
AIR FILTERS
SERVICE LIFE
CHEMICAL EXPLOSIVES
REMOVAL
NUCLEAR WEAPONS
DECOMMISSIONING
PARTICULATES
PRESSURE DROP
PERFORMANCE
DECOMPOSITION
420202
450200
450100
PROTECTIVE STRUCTURES AND EQUIPMENT
NUCLEAR EXPLOSIONS AND EXPLOSIVES
CHEMICAL EXPLOSIONS AND EXPLOSIVES