Mitigation Dust Loading REMP Air Samplers

Dust Loading Definition / Symptoms

Accumulation of loose particulate matter on air sampling particulate filter media

Reduction in air sampler flow rate due to accumulation of material on the air sampler surface

Increase in back pressure across air sample filter media

Why it’s a Problem

Dust loaded REMP air samples may not be representative

Chronically dust loaded air sampling equipment may be more prone to mechanical failure

REMP Air Sampler Dust Loading at SONGS

REMP air sampling apparatus consisted of sample line feed from the exterior of the “doghouse” style enclosure to and in-line type sample cartridge

Observed loose particulate matter on most REMP air sampler

Occasional episodes of reduced flow and increased media back pressure ~ 5% of samples dust loaded

Proposed Remedy

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 Two (2) auxiliary open face samplers were

installed at the same location as two REMP stations

Duplicate data collected for 15 months

Data and Observations

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