April 5th, 2011 – Praire Island Nuclear Power Plant Confirms I-131 from Japan

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From: Zurawski, Paul
Sent: Tuesday, April 05, 2011 11:34 AM
To: Giessner, John; Duncan, Eric; Lerch, Robert; Wengert, Thomas; Phalen, Martin
Cc: Barker, Allan; Logaras, Harral; Mitlyng, Viktoria; Chandrathil, Prema; Shah, Swetha
Subject: FW: Radiation testing results (2).doc

The PI RIO received a courtesy call from the Prairie Island Regulatory Affairs group around 11am this morning informing us that the State of Minnesota Health Department will be issuing a news release sometime this afternoon regarding routine monitoring finding trace amounts of radioactive iodine in air samples.

A draft of the release is attached. After both the Prairie Island and Monticello resident offices are notified, Xcel intends to implement its external stakeholder communication plan.

Our understanding of this means the following:

Xcel Primary Messages (Abbreviated):

” Slightly increased levels of 1-313 have been seen in air and rainwater samples obtained at the sites;
” Xcel will continue to take weekly air and precipitation samples;
” Radioactive levels are extremely small and do not pose any public health risk;
* The sites maintain the required NRC Radioactive Environmental Monitoring Program as required; and
* Levels seen by the sites are consistent with those of the State

External Stakeholders:

* Prairie Island Indian Community;
* State and Local Emergency Manager & Public Safety Officials, WI/MN Public Safety
* MN Public Safety

With information currently available, the MN Department of Health intends to make this news release around 1PM this afternoon.

From: Anderson, Jon S. [mailto:Jon.Anderson(xenuclear.com]
Sent: Tuesday, April 05, 2011 11:05 AM
To: Zurawski, Paul; Stoedter, Karla
Subject: FW: Radiation testing results (2).doc

FOR IMMEDIATE USE Contact: Doug Schultz
April 5, 2011 MDH Communications Office
Sherrie Flaherty
Radiation Control Program

Routine monitoring finds trace amounts of radioactive iodine in air samples

Health officials say amounts from Japan disaster are well below levels of health concern in state

Routine monitoring by the Minnesota Department of Health has found trace amounts of radioactive material likely from the damaged Japanese nuclear power plants in air samples taken in March from St. Paul and two other locations. The amounts recorded are thousands of times less than normal background radiation and well below levels that would be of health concern, health officials said.

Air samples taken from a monitor in St. Paul on March 22 found concentrations of Iodine- 131 that would give the average person a dose 0.004 millirem of radiation over the course of a year. The average person is exposed to at least 365 millirem per year (or 1 millirem per day) from background sources of radiation. Iodine- 131 is a “man-made” isotope or substance that is only found as a byproduct of nuclear fission or reactions, such as those from power plants.

Results from samples taken in St. Paul on March 29 were slightly higher, at 0.011 millirem.

Samples from near the Prairie Island nuclear power plant on March 22 yielded an estimated dose of 0.003 millirem per year.

Samples from near the Monticello nuclear power plant on March 29 showed a concentration that would give a dose of 0.006 millirem per year.

MDH sampling results, including concentration levels, can be found at http://www.health.state.mn.us/divs/eh/radiation/index.html

“The amounts of radiation we are detecting are just a very small fraction of the amount of radiation we are exposed to on a daily basis from a variety of sources,” said Sherrie Flaherty, radiation control supervisor with MDH. A standard chest x-ray will give a dose of about 4-10 millirem and a transatlantic flight will expose the average person to about 7 millirem.

“The exposure level at which we would begin to have concerns for human health is 50 millirem per year,” Flaherty said. (why?) “We are clearly well below that.” Even at the level of 50 millirem, the concern would be for exposure to that same level everyday over the course of 70 years. That amount of exposure could produce a slight statistical increase (what is the factor?) in one’s risk of cancer.

MDH’s findings are consistent with those of other agencies conducting sampling in Minnesota. Air monitoring by the Environmental Protection Agency (EPA) found slightly elevated levels of iodine around March 22 and xx.

Sampling of rainwater in St. Paul by the EPA found a concentration of Iodine 131 on March 22 of 32 picoCuries/liter. It would take a concentration of 1,000 picoCuries/liter to produce a dose of 50 millirem per year.


Sampling by Xcel Energy from sites around its two nuclear power plants has found similar results since the incidents in Japan.

“We fully expected to see some slight increases in radiation as the result of the releases from the reactors in Japan,” Flaherty said, “and that’s what we’re finding.”



Because Minnesota is home to two nuclear power plants, one at Prairie Island and one at Monticello, MDH conducts routine sampling for radiation as part of its environmental monitoring program.

  1. Air samples are taken weekly from a unit in St. Paul and bi-weekly from units at Prairie Island and Monticello.
  2. Surface water is sampled quarterly from the Mississippi River at sites just downstream from the power plants.
  3. Samples of milk from a farm downwind from each of the power plants are taken and tested monthly (no results from March were yet available for this press release).
  4. However, because some radioactive material has been found in milk elsewhere in the U.S., MDH has begun sarfipling milk weekly to make sure nothing of significance is turning up on local dairy farms. (better way to state why we’re going weekly?)


MDH may increase the frequency of other sampling if further test results indicate a need to monitor more closely.

“Unless there are continued releases from Japan’s nuclear power plants, we would expect to see the levels of radioactive substances in Minnesota be undetectable in four to six weeks and to be gone entirely from the environment in about two months,” Flaherty said.

More information on MDH’s radiation control program is available on the MDH website or by calling 651-201-4600x?


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