1 / 19

Radiological Monitoring of Air and Drinking Water in British Columbia

Radiological Monitoring of Air and Drinking Water in British Columbia Following the Fukushima Nuclear Incident. Environmental Health Services (EHS) British Columbia Centre for Disease Control (BCCDC). 1. Radiological Monitoring of Air and Drinking Water in British Columbia

hedy
Download Presentation

Radiological Monitoring of Air and Drinking Water in British Columbia

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Radiological Monitoring of Air and Drinking Water in British Columbia Following the Fukushima Nuclear Incident Environmental Health Services (EHS) British Columbia Centre for Disease Control (BCCDC) 1

  2. Radiological Monitoring of Air and Drinking Water in British Columbia Following the Fukushima Nuclear Incident • ANALYSIS OF DRINKING WATER IN BC: • VANCOUVER: • CAPILANO INTAKE • SEYMOUR INTAKE • COQUITLAM INTAKE • VICTORIA

  3. Testing for radioactivity in drinking water was carried out after the Fukushima nuclear incident by Metro Vancouver for the Vancouver area and Capital Regional District Water Services (CRD) for Victoria. The results of the assays are posted on their respective websites 1. • The tests included the measurement of natural Gamma emitters based on radioactive decay of uranium and thorium series, artificial Gamma radionuclides (Cesium-134, Cesium-137, Iodine-131) and Gross Alpha & Gross Beta. • Most of the results were below the limits of detection of the radiation-measuring systems. These limits depend on the radiation background at the time of measurement and differ from one radionuclide to another. The limits of detection as reported by the labs ranged from 0.01 to 0.02 Bq/L for Alpha & Beta emitters and 0.02 to 0.9 Bq/L for Gamma emitters. • No measurable radioactivity from Fukushima was detected in drinking water supplied by Metro Vancouver plants: Capilano, Seymour, and Coquitlam. • Results from Metro Vancouver are shown on Figures 1, 2, and 3 and from CRD/Victoria on Figure 4 • The Canadian Action Levels for drinking water 2 (see Table 1) are: • 100 Becquerels per liter for Gamma emitters (Cs-134, Cs-137, I-131…) • 1 Becquerel per liter for Alpha emitters (Plutonium isotopes and Americium-241) • The absence of measurable activities of important Gamma emitters from nuclear reactors such as Cesium-137, Cesium-134, Iodine-131 suggests that the traces of Alpha and Beta radioactivity found in the water samples are most probably due to natural radioactivity (Uranium and Thorium decay chains). • 1 Metro Vancouver: http://www.metrovancouver.org/services/water/qualitytreatment/Pages/Radionuclidemonitoring.aspx • Victoria: http://www.crd.bc.ca/waterquality/radiationtesting.htm • 2 single action level for each radionuclide - Ref: Canadian Guidelines for the Restriction of Radioactively Contaminated Food and Water Following a Nuclear Emergency – Health Canada, 2000, • http://www.hc-sc.gc.ca/ewh-semt/alt_formats/hecs-sesc/pdf/pubs/contaminants/emergency-urgence/01_254_hecs-sesc-eng.pdf

  4. Table 1 - Canadian Guidelines for the Restriction of Radioactively Contaminated Food and Water Following a Nuclear Emergency – Health Canada, 2000

  5. Figure 1. ANALYSIS OF DRINKING WATER – CAPILANO INTAKE - 2011 100 Bq/liter: Health Canada Limit for each Gamma Emitter (Cs-134, Cs-137, I-131) 1Bq/liter: Health Canada Limit for each element: Pu-238, Pu-239, Pu-240, Pu-242, Am-241 Source of raw data: Metro Vancouver http://www.metrovancouver.org/services/water/qualitytreatment/Pages/Radionuclidemonitoring.aspx

  6. Figure 2. ANALYSIS OF DRINKING WATER – SEYMOUR INTAKE - 2011 100 Bq/liter: Health Canada Limit for each Gamma Emitter (Cs-134, Cs-137, I-131) 1Bq/liter: Health Canada Limit for each element: Pu-238, Pu-239, Pu-240, Pu-242, Am-241 Source of raw data: Metro Vancouver http://www.metrovancouver.org/services/water/qualitytreatment/Pages/Radionuclidemonitoring.aspx

  7. Figure 3. ANALYSIS OF DRINKING WATER – COQUITLAM INTAKE - 2011 100 Bq/liter: Health Canada Limit for each Gamma Emitter (Cs-134, Cs-137, I-131) 1Bq/liter: Health Canada Limit for each element: Pu-238, Pu-239, Pu-240, Pu-242, Am-241 Source of raw data: Metro Vancouver http://www.metrovancouver.org/services/water/qualitytreatment/Pages/Radionuclidemonitoring.aspx

  8. Figure 4. ANALYSIS OF DRINKING WATER – VICTORIA, BC - 2011 100 Bq/liter: Health Canada Limit for each Gamma Emitter (Cs-134, Cs-137, I-131) 1Bq/liter: Health Canada Limit for each element: Pu-238, Pu-239, Pu-240, Pu-242, Am-241 Source of raw data: Metro Vancouver http://www.metrovancouver.org/services/water/qualitytreatment/Pages/Radionuclidemonitoring.aspx

  9. Radiological Monitoring of Air and Drinking Water in British Columbia Following the Fukushima Nuclear Incident • 2. Air Dose Rates (μSv/Day) • Abbotsford • Burnaby • Kamloops • Kelowna • Port Hardy • Prince George • Prince Rupert • Tofino • Victoria • Vancouver

  10. Health Canada routinely monitors Gamma radiation levels in air by means of sensitive monitoring stations located across Canada. • Following the Fukushima nuclear incident, additional monitoring stations were added in BC. • From March to September 2011, dose rate ( in (µSv/day) readings3 were recorded by Health Canada at 10 locations in British Columbia: Abbotsford, Burnaby, Kamloops, Kelowna, Port Hardy, Prince George, Prince Rupert, Tofino, Victoria, and Vancouver. • A set of data for the period March-September 2011 is available at Health Canada’s website:http://www.hc-sc.gc.ca/hc-ps/ed-ud/respond/nuclea/data-donnees-eng.php#tphp • A summary of Health Canada’s data for the 10 BC locations is shown on Figure 5. • The highest air dose rate recorded in 2010 before the Fukushima nuclear incident was 0.97 μSv/Day. The highest dose rate recorded in 2011 in BC was 0.93 μSv/Day . • The readings show no appreciable increase in radiation levels over “normal day-to-day fluctuations”, as stated by Health Canada. • 3From March 11 to end of April, 2011: Daily Average and From May 4 to September 7, 2011: Weekly Average

  11. MAXIMUM 2010 (0.97) MAXIMUM 2011 (0.93) Raw data from Health Canada: http://www.hc-sc.gc.ca/hc-ps/ed-ud/respond/nuclea/data-donnees-eng.php#fpn

  12. Radiological Monitoring of Air and Drinking Water in British Columbia Following the Fukushima Nuclear Incident • 3. Health Canada’s Fixed Point Surveillance (FPS) network monitors: • Vancouver Island System – Comparison of 2010 and 2011 radiation Levels • From Health Canada4: • The Fixed Point Surveillance network monitors public radiation dose due to radioactive materials in the atmosphere. • It is used primarily to measure the external dose from three noble gases in particular; Argon-41,Xenon-133 and Xenon-135, as well as the total combined external dose from all sources, measured as Total Air KERMA5. • 4 http://www.hc-sc.gc.ca/ewh-semt/contaminants/radiation/surveill/data-donnees/data-donnees-2010 eng.php • 5Kerma is the acronym for “Kinetic Energy Released in Matter”. It is the radiationabsorbed dose in • air,expressed in units of Grays (Gy).

  13. The minimum detectable doses6 for the three noble gases Argon-41, Xenon-133, Xenon-135 are: The FPS system monitors the following locations in British Coliumbia: SAANICH METCHOSIN VICTORIA NANAIMO SIDNEY Figures 6, 7, 8, 9, and 10 show the monthly variations of the radiation levels in air in 2010 and 2011 at the 5 locations. The acceptable public dose limit 7set by the Canadian Nuclear Safety Commission (CNSC) is 106 nGy/month. 6Health Canada: http://www.hc-sc.gc.ca/ewh-semt/contaminants/radiation/surveill/data-donnees/data-donnees-2010-eng.php 7Source: http://laws-lois.justice.gc.ca/eng/regulations/SOR-2000-203/page-1.html#ord

  14. JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC • FOR SAANICH: • - The recorded radiation levels in units of nanoGray/month are far below the Canadian acceptable public dose limitof 1,000,000 nGy/month • No Ar-41, Xe-133, or Xe-135 detected (Below Detection Limit) • The Figure shows the variations of the total Air Kerma in Saanich during • 2010 (before the Fukushima nuclear incident ) and 2011 (after the incident). • Monthly variations in 2010 and 2011 are similar • - There was no radiation spike in 2011above the 2010 background

  15. JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC • FOR METCHOSIN: • Radiation levels are far below the Canadian acceptable public dose limitof 1,000,000 nGy/month • No Ar-41, Xe-133, or Xe-135 detected (Below Detection Limit) • Monthly variations in 2010 and 2011 are similar • - No radiation spike in 2011 above the 2010 background

  16. JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC • FOR VICTORIA: • Radiation levels are far below the Canadian acceptable public dose limitof 1,000,000 nGy/month • - Recorded radiation levels in 2011 and 2011 were extremely low • Monthly variations in 2010 and 2011 are similar • - No radiation spike in 2011 above the 2010 background

  17. JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC • FOR NANAIMO: • Radiation levels are far below the Canadian acceptable public dose limitof 1,000,000 nGy/month • No Ar-41, Xe-133, or Xe-135 detected (Below Detection Limit) • The monthly variations in 2010 and 2011 are similar • - No radiation spike in 2011 above the 2010 background

  18. JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC • FOR SIDNEY: • Radiation levels far below the Canadian acceptable public dose limitof 1,000,000 nGy/month • No Ar-41, Xe-133, or Xe-135 detected (Below Detection Limit) • Monthly variations in 2010 and 2011 are similar • - No radiation spike in 2011 above the 2010 background

  19. 3. CONCLUSIONS: Radiation monitoring of water and air was conducted after the Fukushima nuclear incident at several locations in British Columbia. The results of the tests for radionuclides in water by Metro Vancouver and Capital Regional District Water Services (CRD) of Victoria did not reveal radioactivity at a level of concern The testing for the main reactor Gamma emitters, i.e. Cs-134, Cs-137, I-131 showed no presence of these radionuclides above the instrument detection limit. The traces of Alpha and Beta elements measured in water were most probably due to the presence of natural radioactivity (uranium and thorium decay chains). The air Gamma dose rates recorded by Health Canada during the period March-September 2011 and compared to the 2010 levels showed no sensitive increase of radiation levels in the Province of British Columbia. The radiation levels recorded by the US EPA/RADNET8 at different locations of the West Coast of the United States after the Fukushima nuclear incident show no sensitive increase of radiation in 2011. Additional information on the present status of the Fukushima nuclear power plant available at the International Atomic Energy Agency (IAEA) website.9 8RadNet Monitoring System Data Sources: http://www.epa.gov/radnet/radnet-data/online-data.html 9 Fukushima Daiichi Status Report http://www.iaea.org/newscenter/focus/fukushima/statusreport230212.pdf

More Related