analyzed milk in this study and had one instance of a result above
the minimum detectable activity within the study period (from 3/
19/11 to 4/18/11).
3. Results
The data obtained from GEL and CDPH were submitted by DCPP
to the Nuclear Regulatory Commission and are available on the NRC
website as a collection of PDF files (U.S. Nuclear Regulatory
Commission (NRC), June 2013a). The following Tables 2e6 and
Figs. 1e5 display the iodine-131 results from the various sample
matrices taken from these data (U.S. Nuclear Regulatory
Commission (NRC), June 2013b) (U.S. Nuclear Regulatory
Commission (NRC), June 2013c). The following charts (Figs. 1e5)
are normalized to Day 0 being 3/19/11.
The average activity concentration graphs are displayed with
error bars that are derived from the standard deviation of a group of
samples on that particular day. Error bars are not displayed in the
average charts for days when only one result was available. All
sample results have their respective 2sTPU or CE values in the data
tables.
Not included in the charts or data tables are some positive
iodine-131 results that fell outside of the study date range. An air
charcoal cartridge with an integrated sampling date of March 17,
2011, showed a positive result for iodine-131 at station 7D1-2. The
amount detected at this station was 0.0177 Bq/m3 (±0.00165).
On May 2, 2011, after two weeks of results that were below
detection limits from both laboratories, a final instance of iodine-
131 detection in Cal Poly milk occurred in samples analyzed by
both GEL and CDPH. GEL reported 0.0577 Bq/L (±0.0193) and CDPH
reported 0.153 Bq/L (±0.0337). There were no other corresponding
air, vegetation or water samples that showed positive results for
radioiodine.
All of the raw data activities have been converted to SI units
from picocuries with the volumes remaining in SI units. The individually
charted data points are shown with their respective error.
GEL reports error as 1.96 times the Total Propagated Uncertainty
(TPU) (Trent, May 2012 October 2013). This is displayed as 2sTPU