New filter efficiency test for future nuclear grade HEPA filters
We have developed a new test procedure for evaluating filter penetrations as low as 10/sup /minus/9/ at 0.1-..mu..m particle diameter. In comparison, the present US nuclear filter certification test has a lower penetration limit of 10/sup /minus/5/. Our new test procedure is unique not only in its much higher sensitivity, but also in avoiding the undesirable effect of clogging the filter. Our new test procedure consists of a two-step process: (1) We challenge the test filter with a very high concentration of heterodisperse aerosol for a short time while passing all or a significant portion of the filtered exhaust into an inflatable bag; (2) We then measure the aerosol concentration in the bag using a new laser particle counter sensitive to 0.07-..mu..m diameter. The ratio of particle concentration in the bag to the concentration challenging the filter gives the filter penetration as a function of particle diameter. The bad functions as a particle accumulator for subsequent analysis to minimize the filter exposure time. We have studied the particle losses in the bag over time and find that they are negligible when the measurements are taken within one hour. We also compared filter penetration measurements taken in the conventional direct-sampling method with the indirect bag-sampling method and found excellent agreement. 6 refs., 18 figs., 1 tab.
- Research Organization:
- Lawrence Livermore National Lab., CA (USA)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 7080119
- Report Number(s):
- UCRL-99446; CONF-880815-5; ON: DE88016277; TRN: 88-034214
- Resource Relation:
- Conference: 20. DOE/NRC nuclear air cleaning conference, Boston, MA, USA, 22 Aug 1988; Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
29 ENERGY PLANNING
POLICY AND ECONOMY
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
22 GENERAL STUDIES OF NUCLEAR REACTORS
AIR FILTERS
CERTIFICATION
NUCLEAR FACILITIES
AEROSOLS
AIR CLEANING
AIR CLEANING SYSTEMS
PARTICLE SIZE
TESTING
CLEANING
COLLOIDS
DISPERSIONS
ENGINEERED SAFETY SYSTEMS
EQUIPMENT
FILTERS
POLLUTION CONTROL EQUIPMENT
SIZE
SOLS
500200* - Environment
Atmospheric- Chemicals Monitoring & Transport- (-1989)
290300 - Energy Planning & Policy- Environment
Health
& Safety
054000 - Nuclear Fuels- Health & Safety
220500 - Nuclear Reactor Technology- Environmental Aspects