Mitigation Dust Loading REMP Air Samplers

1. Mitigation Dust Loading REMP Air Samplers

2. 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

3. 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

4. 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

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

6. 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

7. 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