THE SITUATIONS OF EXTERNAL AND INTERNAL RADIATION EXPOSURE IN - PowerPoint PPT Presentation

THE SITUATIONS OF EXTERNAL AND INTERNAL RADIATION EXPOSURE IN FUKUSHIMA Fukushima Senior High School Koh OIKAWA, Ayane ANZAI, Tetsuri TAKAMI

CONTENTS 1. The Fukushima Accident 2. Harmful Rumors － Agriculture, Tourism, and Discrimination － How people in Fukushima feel 3. The External Radiation Exposure The Internal Radiation Exposure 4. Conclusion

Where is Fukushima ? Fukushima

Where is Fukushima Daiichi Nuclear Power Plant ? In Futaba Town

1. AFTER THE ACCIDENT Personal dosimeter Environmental Air Dose Monitor

1. AFTER THE ACCIDENT Environmental Radiation Dose in Fukushima 3.2 3.2 2.7 2.7 Environmental Dose(mSv) Environmental Dose (mSv) 2.2 2.2 1.7 1.7 Coastal Northern Area area 1.2 1.2 Normal Normal 0.7 0.7 0.2 0.2 2011 2012 2013 2014 2011 2012 2013 2014 -0.3 -0.3 YEAR YEAR T hey haven’t gone back to normal.

1. AFTER THE ACCIDENT The number of Fukushima refugees has hardly decreased 180000 95316 160000 102180 140000 120000 Refugeees within 100000 Fukushima 80000 Refugees out of 62038 Fukushima 60000 40000 53277 20000 0 2012.June 2013.July

2. HARMFUL RUMOR 2-1. Agriculture ① Peach → Although the shipment has returned, the price hasn’t returned. The price of peaches in Fukushima Yen/kg 500 400 300 200 100 0 2010 2011 2012 Yen/kg 441 167 335

2. HARMFUL RUMOR 2-1. Agriculture ② Rice → The price in Fukushima is still below the average because of the harmful rumor. The price of rice in Fukushima Yen/kg 20500 20000 19500 19000 18500 18000 17500 2011 2012 2013 Rice yen/kg 19900 18500 19500

2. HARMFUL RUMOR 2-2. Tourism → Japanese tourists are not willing to visit Fukushima rather than foreign tourists. The number of tourists 3000000 2500000 2000000 1500000 1000000 500000 0 2010 2011 2012 Japanese tourists 2595824 2591298 2422640 Foreign tourists 83000 35000 55000 Foreign tourists Japanese tourists

2. HARMFUL RUMOR 2-3. Discrimination Example of discrimination outside Fukushima • Children were treated badly, so their parents decided to return to Fukushima. • People were required to hand in some reports of radiation inspection. • Some people were refused to check-in hotels, take a taxi, or enter a restaurant. One reason: People in general did not understand radiation well and were more afraid than necessary

2. HARMFUL RUMOR 2-4. Thoughts of people in Fukushima ① Interview to school lunch center • “We want to continue to eat local food actively.” • The radiation standard for shipment of food for school lunch is very strict: 10 Bq/kg cf. Food for market in Fukushima: 100 Bq/kg cf. in EU: 500 - 1250 Bq/kg

2. HARMFUL RUMOR 2-4. Thoughts of people in Fukushima ② Interview to my classmates Some say: "We are still doubtful.” However, most say: "We are not afraid of using food made in Fukushima." "We don't care about radiation dose." Most people living in Fukushima do not worry about radiation so much.

3. The External and Internal Radiation Exposure External exposure is being exposed to radioactive substances outside our bodies.

3. The External and Internal Radiation Exposure Internal exposure is being exposed to radioactive substances inside our bodies. e.g.) eating, breathing

3. The External and Internal Radiation Exposure • Sv (Sievert )… A unit to express the extent of biological effect on living bodies of radiation exposure. • Bq (Becquerel )… A unit to express how much an object has been contaminated.

3. The External and Internal Radiation Exposure You can convert Bq into Sv with effective dose coefficients (see the table below). Isotope Half-life Ingestion Inhalation (year) (Sv/Bq) (Sv/Bq) 1.9 × 10 -8 2.0 × 10 -8 134 Cs 2.06 1.3 × 10 -8 3.9 × 10 -8 137 Cs 30.0

3-1. The External Exposure • Integrated dosimeter “GLASS BADGE”

3-1. The External Exposure Measurement of radiation level with a Measurement of radiation level with a dosimeter dosimeter In 2011 In 2012 81 78 100 100 18 12 9 10 10 1 rate 【％】 0 0 0 rate 【％】 0 0 0 0 1 1 0 ～ 0.1 0.1 ～ 0.5 0.5 ～ 1.0 1.0 ～ 1.5 1.5 ～ 2.0 2.0 ～ 2.5 2.5 ～ 3.0 Average value of the accumulated dose for three months : 0.26mSv in 2011. － 0.13mSv Average value of the accumulated dose for three months : 0.14mSv in 2012. ・ Cumulative dose of radiation has decreased nearly in half.

3-1. The External Exposure ・ 90% of Fukushima residents were exposed to less than 0.5mSv over 3 months. ・ This is less than 2.0mSv/year . ・ The ICRP excess radiation limit is 20mSv/year . ・ The global average of natural radiation is 2.4mSv/year . Fukushima residents were NOT exposed to large amounts of radiation.

3-2. The Internal Exposure Monitoring Investigation of Daily Meals • Examination method… All meals, snacks, and drinks from one day were measured together by using germanium semiconductor detector. • Inspection period… Dec. 2 nd , 2012~Feb. 9 th , 2013 • Respondent to this survey… ordinary people selected at random: 78 people

RESULTS 3-2. The Internal Exposure Monitoring Investigation of Daily Meals: Result • Measured values are in 0.076 ～ 22Bq/(person ･ day ). • 4 people have been exposed to radiation over 3Bq/(person ･ day). • Most people have been exposed radiation under 1Bq/(person ･ day). Intake of radioactive cesium in daily meals [people ] 64 7 3 4 [Bq/person ・ day] 1 ～ 2 2 ～ 3 3 ＜ 22

RESULTS 3-2. The Internal Exposure Monitoring Investigation of Daily Meals: Result • Max.: 22Bq/day= 0.12mSv/year << Below ICRP ’s safety standard: 1mSV/year cf. You have to eat about 70,000Bq for a year to get 1mSv. << Below the natural dose of 40 K: 0.18mSv/year 1.2 [mSv] 1 0.8 0.6 1 0.4 0.2 0.18 0.12 0 40 K Result ICRP' food safety 23 standard

4. Conclusion The 2 types of investigations: the investigation with integrated dosimeters, and monitoring investigation of daily meals show: We can clearly claim that Fukushima is SAFE .

Thank you for listening!