This powerpoint presentation begins by presenting a brief overview of radionuclides and how they are formed. The Colorado Radionuclide Abatement and Disposal Strategy is presented, along with the Radionuclide Sample Variability Investigation. The project approach included a
literature review,
laboratory standard operating procedures (SOPs) Review and Survey,
and a confirmation sampling program. Lessons learned from sampling include the following:
lab selection could impact compliance;
same sample analyzed by various laboratories produced a
wide variety of results for GAA and radium;
variability could be attributed to a wide variety of issues;
for example, sample volumes analyzed, sample
preparation methods, calibration standard selection, and
count times;
conversion of uranium from mass to activity can have
significant compliance implications;
for example, using the conservative 0.67 pCi/ug mass to
activity ratio can result in non-compliance with adjusted GAA. Big picture recommendations include the following:
use U.S. Environmental Protection Agency's (USEPA's) GAA Method 900.0 for screening purposes;
for example, if GAA > ~5 and <~30 pCi/L: require system to conduct
additional sampling using USEPA Method 00-02 (co-precipitation),
which is believed by some industry experts to be more accurate and
precise;
further evaluate GAA variability using EPA Method 00-02;
further investigate radium variability;
for systems that have potential adjusted GAA compliance issues
and confirmed uranium present: identify source-specific mass-to-activity
ratio;
measure U-238 to U-234 isotopically and determine conversion or
measure uranium activity directly. Impacts to Colorado Department of Public Health and Environment (CDPHE):
direct benefits to CO-RADS;
consistent sampling and analysis protocols were used to ensure better
quality data;
understanding variability provided insight during data evaluation;
indirect benefits to Laboratory Certification Program;
greater awareness of issue and potential magnitude;
increased scrutiny of certified labs; and,
issues will need additional investigation before long term
improvements will be made. Includes tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 1.3 MB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 30 |
| Published : | 11/01/2008 |
