Welcome to the Fall 2013 edition of Inreach. This semester we are continuing our work with the biology project from the winter 2013 session. However this time, the project will focus on the effect of tritium in human cells.

Biology Project: Biology: Developing Bio-indicators for use in Risk Assessments.

As always, we will provide students and teachers with additional reference material and interesting links for the biology project. To get immediate updates you can follow us on Twitter or Facebook. The links are to the right of the screen.

 

Week 12: Adventures in Biological Research: Chernobyl

A fascinating look at the wolves in Chernobyl. The documentary can be found here:

The book Brant recommends is: Wormwood Forest: A Natural History of Chernobyl by Mary Mycio. She also has a Facebook page: www.facebook.com/Chernobyl.Wormwood

Week 11: Summary

Our Inreach classes had some excellent questions on radiation, Fukushima, and tritium levels. Brant found a fantastic 3-part series that explains everything, and questions everything. It is a bit long, but worth the read!

Stayin’ alive in the gene pool – Part I

Stayin’ alive in the gene pool – Part II

Stayin’ alive in the gene pool – Part III

Week 10: Data Interpretation/Homework

Click on the link for the homework data. Homework Sheet – analyzing data

 

Week 8/9: Dose Response with Lab Video

Week 7: Biological Responses / Dose Responses

A different perspective on Dose Responses from a DNA point of view:

 

Week 5: Tritium

Answers to some questions from students on the tritium presentation.

1. How much tritium is released from low-level radioactive waste in DGR (Deep Geological Repository)?

There is some tritium in the low-level radioactive materials generated around the reactor, but this is small compared to the tritium generated in the heavy-water moderator and coolant. It is the generated tritium that has controlled releases. This tritium is in the form of water. As Brant points out, it is extremely diluted in lake water to levels barely above background.

The primary source of natural tritium is cosmic rays generating free neutrons in the upper atmosphere that are absorbed by nitrogen (the major constituent of air) to generate carbon and tritium. The tritium comes down as rain.

Tritium from low-level radioactive waste is very, very small compared to natural sources and controlled releases from nuclear facilities.

2. Why does lead (Pb) stop gamma radiation?

Lead is very dense. It has a density of about 11.3 g per cubic centimeter, 11 times that of water and 50% more than steel.

It has a high atomic number (82 on the periodic table) and large nucleus (atomic mass of 207). As a result, it has a lot of electrons and the nuclei have a large positive electric charge. Gamma rays are electromagnetic radiation, so they interact with electrons and nuclei. Basically lead packs a lot of stuff in a small package and that makes it hard for gamma rays to get through.

It is interesting to note that lead is good for stopping alpha, beta and gamma radiation (they all interact with electrons) but it is not good for stopping neutrons. The lead nucleus has a relatively small cross section for neutrons. Paraffin wax is better at stopping neutrons than lead.

 

Week 4: Radiation

This week we touched very briefly on the “funky blue glow” from the research reactor at McMaster University. For more information on Cherenkov radiation (aka “funky blue glow”) and nuclear reactors, you can check out Week 2 of our Physics Inreach Project.

Physics Week 2: Nuclear Reactors

 

Week 3: Cell Targets and Stress

 Week 2 – Cell Lines

“Why are we using blood and testicular cells?”

We use blood cells to determine systemic changes. Blood cells can provide information relevant to the organism level.
We use testicular cells as a population marker (if the organism cannot reproduce, the population will not be sustainable).
Both these cell types are used to extrapolate data for higher up the biological/ecological pyramid (referenced from the first lesson).

World’s Tritium Inventory:
Naturally occurring tritium can come from one of two sources: cosmic rays (reactions with nitrogen or oxygen) and the earth’s crust (reactions with Lithium or Uranium). The levels of naturally created tritium in the world’s inventory is around 5-7 x 1016 Bq/ year. Approximately 2.1 x 1016 Bq/ year comes from nuclear processes which is significantly less than naturally created tritium. However, 1.4 x 1019 Bq is still left over from previous atomic bomb testing. The amount of tritium accumulated from these atomic bomb tests is slowly decreasing (decaying) since the half life for tritium is around 12 years). The information was taken from Boyer, C, L. Vichot, M. Fromm, Y. Losset, F. Tatin-Froux, P. Guetat and P.M. Badot. 2009. Tritium in plants: A review of current knowledge, Environmental and Experimental Botany, 67: 34-51.

 

 Week 1 – Introduction

Both our classes had a question about tritium and radiation in the environment. On page 2 of this PDF, there is a map of the tritium dispersion surface around the Pickering nuclear power generating station.

 

Looking for More? Check out these links!

Lots of great questions this week after our session on tritium. One of those questions concerns background radiation in Canada. The Canadian Nuclear Safety Commission (CNSC) has an excellent information sheet on background radiation. We have recreated a table on the background levels in various Canadian cities. We have sorted it from least amount to most amount.

The creator of xkcd.com put together a Radiation Dose Chart which gives a good overview of radiation, from eating a banana to standing next to the Chernobyl reactor after the explosion. If you are curious about radiation exposure in every-day life, check this out:  Radiation Dose Chart.

For a great overview of tritium and the health effects, especially in drinking water, the CNSC has a FAQ sheet with everything you need to know. Tritium Fact-Sheet CNSC

A very interesting study from the Canadian Nuclear Safety Commission (CNSC) “Radiation Exposure and Cancer Incidence (1990 to 2008) around Nuclear Power Plants in Ontario, Canada” by R. Lane, E. Dagher, J. Burtt, P. A. Thompson. Their findings are very surprising!

This is a great site for information on radiation: www.radiationanswers.org

This is one of our favourite videos: a black sand beach located in Brazil. It’s radioactive! Watch the Geiger counter…

If you have any questions about the research or the Inreach program, feel free to contact Seana Jones, Inreach Director, at seana dot jones at drsa dot ca.

The Deep River Science Academy wishes to thank Brant Ulsh and M.H. Chew & Associates, Inc. for their continued work with the DRSA Inreach Program. Without their assistance and dedication, the biology portion of Inreach would not have been possible.