Past and Present: Uranium mining and radioactivity levels at and near the former Daybreak Mine, Spokane County, Washington.

Transcription

1 Past and Present: Uranium mining and radioactivity levels at and near the former Daybreak Mine, Spokane County, Washington. Submitted to: The National Science Foundation Submission Date: July 14, 2013 Jennifer Light Geological Sciences general option University of Idaho: Department of Geological Sciences Abstract: Uranium is a radioactive ore; therefore overtime the decay of the nucleus produces radiation in an area. In 1955 the streams near the Daybreak mine (located 4 miles west Northwest of Mt. Spokane in Spokane County, Washington) were tested for radioactivity and showed levels higher than normal background radiation. There has been no useable radiation data recorded in the Daybreak mine site or the surrounding area since Though in 2011, other uranium mines in eastern Washington were tested to determine whether the levels of radiation emitted are higher than background levels and environmentally unsafe. The goal of this project is to test a five square mile area surrounding the Daybreak mine using a Geiger counter, and note areas of increased radiation. This will allow a better understanding of the radiation levels being emitted. These levels will be compared to the levels found at the nearby Midnite and Sherwood mines to know whether environmental action is needed in this area.

2 PROJECT OVERVIEW In 1955 Leonard and Betty Dahl of Dahl Uranium Mines, Inc. purchased a parcel of land north of Spokane, Washington that was found to contain uranium ore (Docket Index 1955). This particular parcel of land was located a mile east of the property owned by Daybreak Uranium Mines. Both of these plotted areas contained chemically identical uranium ore. Daybreak mine was located on the 160 acre property of Alfred L. Dahl and produced uranium ore from 1957 to 1960 (Spokane Daily Chronicle). The mine was bought out in the mid 1960 s and halted production later that decade due to the closing of Dawn Mill. The mill was shut down because of a lack of high grade ore (Spokane Daily Chronicle). The former Daybreak mine is located 4 miles west northwest of Mt. Spokane, Spokane County, Washington. In 1955 the United States Geological Survey (USGS) conducted a survey of the Daybreak and Dahl areas to confirm suspicions of ore, as well as tested the radioactivity of four springs in the area. What they discovered was high levels of radioactivity (note definitions can be found in Appendix I) compared to background levels. In 1955 of the four springs tested three springs showed radioactivity of about 10 times background; a fifth showed radioactivity of 40 times background ( Weis, Docket Index 1955). These levels appear to be high due to uranium leaching from groundwater, though background levels are not recorded. In researching the former Daybreak mine I was not able to find any data to suggest that radiological testing has been done since the mid 1950 s. My objective is to spend three weeks in the field testing the Daybreak mine and a five square mile area surrounding it. I plan to test levels of radioactivity to see if the radiation has increased, decreased, or remained the same over the last fifty eight years. I plan to test the concentrations of radioactivity in the air using a Geiger counter, to conclude whether present radiation levels are higher, lower, or relatively the same as other nearby uranium mines, and background radiation in the area. This experiment will be conducted to see if the radiation levels are high enough to report to the EPA for further environmental action. LITERATURE REVIEW Figure 1: Overhead view of Daybreak Mine from Google Earth During the 1950 s three major uranium mines were located in eastern Washington State. The Midnite and Sherwood mines were both open pit uranium mines, located within eight miles of Wellpinit, Washington, and 40 miles west of the Daybreak mine. Dawn Mill (located 25 miles east of Wellpinit) was the only uranium mill in the area and received uranium ore from Midnite, Sherwood, and Daybreak mines.

3 The Daybreak mine is located west northwest of Mt. Spokane, Spokane County, Washington. The parcel of land it is located on is owned by Inland Empire Paper Company and used for timber. The terrain of the area surrounding the former mine is hilly with dense patches of forest. A mile east of the mine are where the four springs that were tested in the 1950 s should be located, it has not been determined yet whether the streams are still flowing or whether they have dried. However, dried stream beds will still give me a reading. If the streams are still flowing they could pose a potential danger to wildlife if the levels were found to be too high. So far no testing has been done in the Daybreak area unlike the Midnite and Sherwood mines. According to an Environmental Protection Agency (EPA), Office of Emergency Management report; in 2011 the EPA and the Spokane Tribe of Indians conducted aerial radiological surveys of the Midnite Mine, Sherwood Mine, and Dawn Mill areas (Environmental Protection Agency 2011). They surveyed roughly 40 square miles including the three uranium localities (Environmental Protection Agency 2011); using a process known as aerial gamma spectroscopy. They flew over the area using previously mapped sections at an altitude of 500 ft above the surface, measuring gamma rays given off by radioactive decay (Environmental Protection Agency 2011). What they discovered was that most of the area did not show any significant cause for concern. The radiation levels through much of the area surveyed were within normal levels of exposure, at between 5.0 and 20.0 μr/hr (microroentgen per hour)( Environmental Protection Agency 2011). However, the mill, and the Sherwood mine sites had elevated readings and the Midnite mine had significantly higher exposure rates. The exposure rate for the mill and Sherwood mine was between 25.0 and 30.0 μr/hr (Environmental Protection Agency 2011). For the Midnite mine the exposure rate was between 25.0 and greater than 45.0 μr/hr (Environmental Protection Agency 2011). To put this in perspective the background radiation of St. Croix, in the U.S. Virgin Islands is μR/hr (Petrait, GeoCities.com). To be fatal, a human would have to be exposed to a dose of 100,000,000μR/hr for 5 hours (Introduction to radiation 101). Therefore dosages in this area are not at fatal levels according to the information found in this study. However, the EPA is concerned with possible water and soil contamination. Much like the survey done by the EPA and the Spokane Tribe of Indians, I would be surveying and mapping the radiation exposure levels around the Daybreak mine, to see if they are within acceptable range much like the Sherwood and Dawn mill sites or whether the exposure rates are much higher like the Midnite mine. In comparison to aerial gamma spectroscopy, the technology I will be using is primitive, though the tests will still be done effectively. METHODS This experiment will take place in three steps. Step 1: Obtain permission to access privately owned lands As of July 15, 2013 I have obtained the information needed to contact the parcel owners of the Daybreak mine as well as the surrounding areas. Telephone messages have been left requesting access to the Daybreak mine property. I will continue to contact surrounding parcel owners in the next two weeks.

4 Step 2: Begin gathering data I will be in the field for three weeks starting August 1 st, A more specific timeline will be provided at the end of this section. I plan to cover a 5 square mile area around the mine, mostly on foot while gathering readings. I have created a map using Google earth, and sectioned off smaller more manageable areas to cover using Microsoft word (Image to be found in Appendix II). I will carry a copy of this map as well as a topographic map of the area with me in the field to record data. Two readings (taken in the Northwest and Southeast corners) will be taken in each smaller square section using a Geiger counter. I will then write the results in the form of a table in my notebook and plot each result on my maps. One of my main goals will be to find the stream beds mentioned in the documents from 1955 and test the radioactivity to see if it has increased, decreased or stayed the same, in comparison to today s background level readings. I will also play close attention to testing the open pit mine itself. Step 3: Analysis After collecting my data I will produce a map using ArcGIS 10 (a geographic information systems software), to visually show the varying levels of radiation. I will use a gradient color scale, with red being the highest exposure levels and blue being the lowest. No data so far has been published on the radiation levels of the mine site; I will therefore compare my results with those found at the Midnite and Sherwood mines. To determine if the levels I have found are cause for environmental concern or within normal background radiation limits. I plan to produce a report of my findings along with a detailed map of the area showing the radiation levels. This information will be made available to the public three months after data collection has been completed. Time Line July 15, July 29, 2013 Aug. 1, 2014 Aug. 22, Request access to private lands from parcel owners Collect radiation data in the five square mile testing area. Aug. 23, Nov. 23, Analyze, prepare, and organize my data into a report and accompanying map, which highlights my findings. Nov. 24, Release my report and findings to the public. PREPARATION As a geology major I have taken, or will take courses in the following, that qualify me to successfully complete this project.

5 Geographic information systems: This course teaches students too efficiently work with software applications to build data related maps. Field Geology 1: This course teaches basic orienteering as well as map drafting in the field. It requires accuracy as well as analytical decision making. Chemistry 111 and 112: In this students briefly learn about radiation and how a Geiger counter is used. Geochemistry: I will be taking this course in the fall of 2013; this course is taught by Leslie Baker who has written many papers on radiation contamination in soils found near mining areas. Her course will also cover radioactive decay and radiation from bedrock.

6 Investigator Budget Part 1 For items over $100, please list them below and, in Part 2, include an explanation of their relevance to the proposed project. Equipment (Itemized) Amount 1. (1) Geiger Counter: Radalert 100 (Radalert 100) $ Equipment Total $ Materials and Supplies (Itemized) Amount 1. (1) Rite in the Rain: Field notebook $ Materials and Supplies Total $20.00 Travel Costs (Itemized) Amount 1. Gasoline $ Travel Costs Total $ Personnel/Services (Itemized) Personnel/Services Total Amount Other Expenses (Itemized) Amount

7 Other Expenses Total Total Request $ Investigator Budget Part 2 For each item over $100 listed in Part 1, provide a justification of its importance to the proposal. Include the category (equipment, materials and supplies, etc.), item number, and justification. Category Item # Justification Equipment 1 A Geiger counter is a device used to detect the precise levels of radiation an object emits. This device also works to test the radioactivity of an area. Travel Costs 1 I need to be able to travel from Moscow to Spokane. As well as from my place of lodging in Spokane Valley to the field site daily (a drive of roughly 70 miles round trip) for three weeks (18 round trips in total) to be able to map and collect data.

8 BIBLIOGRAPHY Docket Index. USGS, n.d. Web. 13 July <minerals.usgs.gov/dockets/scans/wa/dmea/3885_dmea.pdf>. Environmental Protection Agency. "Spokane Tribe of Indians Airborne Radiological Surveys Spokane, WA."epa.gov. United State Environmental Protection Agency: Office of Emergency Management, n.d. Web. 13 July < "gamma ray (physics) -- Encyclopedia Britannica." Encyclopedia Britannica. N.p., n.d. Web. 13 July < "Introduction to Radiation 101."IDAHOQUAD.COM. N.p., n.d. Web. 13 July < Petrait, James. "Data from the Background Radiation Survey." Yahoo! GeoCities: Get a web site with easy-to-use site building tools.. N.p., n.d. Web. 13 July < "Radalert 100." GeigerCounters.com. N.p., n.d. Web. 13 July < "Radiation Doses in Perspective Radiation Protection US EPA." US Environmental Protection Agency. N.p., n.d. Web. 13 July < "Radioactivity - Definition and More from the Free Merriam-Webster Dictionary."Dictionary and Thesaurus - Merriam-Webster Online. N.p., n.d. Web. 13 July < "Spokane Daily Chronicle - Google News Archive Search." Google News. N.p., n.d. Web. 13 July < sjid=yvcdaaaaibaj&pg=7129, >. Weis, Paul. "Memorandum." Docket Index. USGS, n.d. Web. 13 July <minerals.usgs.gov/dockets/scans/wa/dmea/3885_dmea.pdf>.

9 APPENDIX I Definitions Aerial gamma Spectroscopy- Measures from the air, the precise amount of photons expelled by varying nuclei (Britannica.com). Background Levels- Background levels are caused from radiation from the sun, and natural decaying of bedrock, levels are usually quite low. According to the Environmental Protection Agency (EPA) average annual levels of radiation exposure today from both manmade and natural sources is 6.2 millisieverts; roughly 50% (see figure 2) of this is from background radiation (Radiation Doses in Perspective, epa.gov). Low levels like these do not tend to contribute to health risks. Figure 2: Annual radiation (Radiation Doses in Perspective, epa.gov) Gamma Ray-The Nucleus of an atom is made of protons and neutrons, these are held together by varying levels of energy depending on the atom. During decay the energy level drops and a photon (a positive electron) is expelled to remove the excess energy. These photons give off an electromagnetic energy wavelength known as a gamma ray (Britannica.com) microroentgen per hour- A unit of gamma ray radiation, which measures the amount of radiation exposure in one hour. Radioactivity- During the disintegration of their atomic nuclei, elements and their isotopes spontaneously expel energetic particles (Merriam-Webster.com). These particles carry with them differing amounts of energy; this energy is known as radiation.

10 APPENDIX II