The Environmental Protection Agency has upgraded its RadNet system for detecting radioactive fallout, the EPA's Office of the Inspector General reported today, two years after the inspector general criticized the agency for lapses in management and maintenance of the system.
"Corrective actions taken by the EPA in response to our recommendations have increased the availability of critical data needed to assess radioactive threats to the public and the environment," according to today's report from the OIG. "There are more air monitors in the network now and a greater percentage of the total monitors are operating properly."
When the meltdown began at the Fukushima nuclear plant on March 11, 2011, twenty percent of EPA'S 124 Radnet monitors were out of service, and half of monitors had not undergone a filter change in more than eight weeks. Filters are supposed to be changed twice weekly, a service the EPA depends upon volunteers to perform.
A wave of fallout from Fukushima crossed the US in March and April of 2011, depositing iodine-131, cesium-137, strontium-89 and other radionuclides of concern.
"Relaxed quality controls" left the system vulnerable, the inspector general said in 2012, and compromised EPA's ability to protect the environment and public health.
In 2013, EPA had improved the number of monitors in service to 92.9 percent. The agency has added eight new monitors, and it has plans to add eight more—including one for South Carolina, the only state currently without one.
EPA has also increased the frequency of sampling and reduced the longest time a monitor has gone without a filter change from 339 days in 2011 to 46 days in 2013, according to the inspector general.
Radnet's 132 stationary air monitors sniff the air and send hourly readings of beta and gamma radiation to EPA's National Analytical Radiation Environmental Laboratory. After volunteers—often high-school science teachers—collect the air filters, NAREL tests them for the presence of specific radionuclides.
EPA also conducts separate tests of precipitation, drinking water and pasteurized milk.
In accordance with the Patriot Act, EPA identified the Radnet system in 2004 as “critical infrastructure” for homeland security.
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