Mitigation Dust Loading REMP Air Samplers Dust Loading

Mitigation Dust Loading REMP Air Samplers

Dust Loading Definition / Symptoms n Accumulation of loose particulate matter on air sampling particulate filter media n Reduction in air sampler flow rate due to accumulation of material on the air sampler surface n Increase in back pressure across air sample filter media

Why it’s a Problem n Dust loaded REMP air samples may not be representative n Chronically dust loaded air sampling equipment may be more prone to mechanical failure

REMP Air Sampler Dust Loading at SONGS n REMP air sampling apparatus consisted of sample line feed from the exterior of the “doghouse” style enclosure to and in-line type sample cartridge n Observed loose particulate matter on most REMP air sampler n Occasional episodes of reduced flow and increased media back pressure ~ 5% of samples dust loaded

Proposed Remedy n n n Change sampling method from in-line type to open face sample method Sampling method recommended by subject matter experts DOE reference

Comparison of Open Face Sampling to In -Line Sampling Method at SONGS n Two (2) auxiliary open face samplers were installed at the same location as two REMP stations n Duplicate data collected for 15 months

Data and Observations n n n Open face sample cartridge samplers had no observed loose particulate matter Most in-line type samples had loose particulate matter on the filter media 15 month in-line type sample gross beta data was about 7% higher than the open face gross beta data About 5% of the in-line samples were dust loaded (increased back pressure and /or reduced flow) Open face samplers had no observed occurrences of dust loading during the study period