Insights into Radiological Impacts from Major Severe Accidents of Nuclear Power Plants

Transcription

1 APSORC 17 Insights into Radiological Impacts from Major Severe Accidents of Nuclear Power Plants Tae Woon Kim (KAERI) Inn Seok Kim, Mi Sook Jang, Ki Ho Park, Seoung Rae Kim (NESS)

2 5 nuclear accidents Source : Hasegawa, 2015

3 Location Kyshtym Accident Date Sept 29, 1957 Type of accident Release of radioactivity Contaminated area INES level 6 Affected population Dose Estimates Implications Kyshtym, Chelyabinsk Oblast, Russia (then USSR) Chemical explosion of containment tank of liquid radioactive wastes at military installation TBq (1⁴⁴Ce and 1⁴⁴Pr: 66%; ⁹⁵Zr and ⁹⁵Nb: 24.9%; ⁹⁰Sr and ⁹⁰Y: 5.4%) Area contaminated with ⁹⁰Sr: 1000 km2 (>74 kbq/m2); km2 (>3 7 kbq/m2) residents evacuated; lived in contaminated area Average effective dose of residents: 170 msv (preceding evacuation); 520 msv (effective dose equivalent) Restriction of information about accident by government Source : Hasegawa, 2015

4 Location Windscale Piles Sellafield, UK Date Oct 10, 1957 Type of accident Release of radioactivity Fire of nuclear reactor at military installation designed to produce Plutonium 131I: 740 TBq Contaminated area No specific information on contaminated area available INES level 5 Affected population Dose Estimates Implications No evacuation ordered Maximum estimated thyroid doses of residents: the order of 10 mgy (adults); 100 mgy (children) Poor preparedness before accident; milk distribution banned 10 km north of Windscale Works to 20 km to the south Source : Hasegawa, 2015

5 Location Three Mile Island Dauphin county, PA, USA Date March 28, 1979 Type of accident Partial core melt at civilian nuclear reactor Release of radioactivity Contaminated area Noble gases [mainly 133Xe]: TBq; 131I: 0 55 TBq No specific information on contaminated area available INES level 5 Affected population Dose Estimates Implications residents living within 32 km evacuated voluntarily Maximum effective dose: 40 msv (emergency worker); effective dose of residents living within 80 km: msv (average); 0 85 msv (maximum) Scarcity of information about nuclear power plant condition and evacuation plan; no effective plan for hospital and nursing care facility evacuation Source : Hasegawa, 2015

6 Location Chernobyl Date April 26, 1986 Type of accident Release of radioactivity Contaminated area INES level 7 Affected population Dose Estimates Implications Chernobyl, Ukraine (then USSR) Core explosion and fire at civilian nuclear reactor 131I: TBq; 137Cs: TBq Area contaminated with 137Cs: km2 (>560 kbq/m2); km2 (>190 kbq/m2) residents evacuated in 1986 ( subsequently evacuated by 1992); lived in contaminated area Workers with acute radiation syndrome: <2 1 Gy (41 people); Gy (50 people); Gy (22 people); Gy (21 people); average thyroid dose of residents: 349 mgy (adult evacuees); 1548 mgy (preschool children evacuees); 138 mgy (adults in contaminated areas); 449 mgy (preschool children in contaminated areas) Restriction of information about accident by government; delay in implementation of public protection; long-term psychological issues Source : Hasegawa, 2015

7 Location Fukushima Fukushima, Japan Date March 11, 2011 Type of accident Release of radioactivity Core melt-through; three reactor cores damaged; three reactor buildings damaged by hydrogen explosions 131I: TBq; 13⁷Cs: TBq Contaminated area Area contaminated with 137Cs: 600 km2 (>560 kbq/m2); 2000 km2 (>190 kbq/m2) INES level 7 Affected population Dose Estimates Implications residents evacuated ( evacuated voluntarily) Maximum effective dose: 678 msv (emergency worker); maximum thyroid dose: 12 Gy (emergency worker); maximum effective dose of residents: 25 msv (external); maximum average thyroid dose of infants in the most affected district: 80 mgy Severe health effects of evacuation and relocation of hospital inpatients and elderly people needing nursing care; psychosocial issues after accident; poor risk communication Source : Hasegawa, 2015

8 Fukushima Source : Hasegawa, 2015

9 Kyshtym

10 Kyshtym

11 Windscale

12 Windscale Contour of I-131 deposition (microcurie / m^2) 1, 0.5, 0.1, (0.01), (0.001) Air concentration of I-131 and Cs , 38 (pci/m^3)

13 Windscale

14 Source Term Comparison between Kyshtym and Windscale (Jones, 2008)

15 Chernobyl Fukushima

16 Chernobyl

17 Chernobyl

18 Source Term Comparison between Chernobyl and Fukushima (Lin, 2016)

19 Source Term Comparison between Chernobyl and Fukushima (Hirose, 2016)

20 Source Terms to Atmosphere (PBq=1.0e15 Bq) Nuclide Kyshtym Windscale Chernobyl Fukushima Global Fallout Xe Kr I Cs Sr Zr Ce Ru Pu ( ) e-6 2.4e-6 10

21 Source Terms to Ocean (PBq=1.0e15 Bq) Nuclide Half-life Natural inventory Reprocessi ng Facilities (total inventory) Reprocessi ng Facilities (2010) Chernobyl Fukushima Global Fallout (total inventory) Global Fallout (2010) H y ,000 8,000 I e6 y 0.6e e-3 0.3e-3 0.3e-3 I d Cs y Sr Source : Povinec, Hirose, Aoyama (Fukushima Accident, Radioactivity Impact on the Environment) Elsevier, 2016, p.226

22 Source : Povinec, Hirose, Aoyama (Fukushima Accident, Radioactivity Impact on the Environment) Elsevier, 2016, p.347

23 Source : Povinec, Hirose, Aoyama (Fukushima Accident, Radioactivity Impact on the Environment) Elsevier, 2016, p.343

24 Conclusions We investigated the accident characteristics of major severe accidents in this paper. As a result of this review, the victims showed a significant mental suffering even though the actual radiation exposure caused by the accident was low. And the epidemiologic impact of the accident may not be judged, but it may lead to long-term cancer death. Therefore, national management of residents after the accidents is very important. The residence space of the victims and the base hospital should be secured quickly and psychotherapy for them should be done in parallel. As it appeared at the beginning of the Fukushima accident, the discrimination against existing local residents and evacuees became a problem. To reduce the mental disorder and health effects of evacuees due to discrimination, national attention is also needed. The severe accident management plan should include measures to prevent accidents and post-accident responses. And issues not related to radiation, such as evacuation and longterm displacement of vulnerable people, and mental, psychological, and social factors, should also be taken into consideration. Reviewing previous accidents will be good resources for establishing the severe accident management plan.

25 References A. Hasegawa, et al., From Hiroshima and Nagasaki to Fukushima 2, Health effects of radiation and other health problems in the aftermath of nuclear accidents, with an emphasis on Fukushima, Vol 386 August 1, 2015 R. Wilson, EVACUATION CRITERIA AFTER A NUCLEAR ACCIDENT: A PERSONAL PERSPECTIVE, Dose-Response, 10: , 2012 S. Jones, Windscale and Kyshtym: a double anniversary, Journal of Environmental Radioactivity 99 (2008) 1-6 G. Steinhauser, A. Brandl, T. E. Johnson, Comparison of the Chernobyl and Fukushima nuclear accidents: A review of the environmental impacts, Science of the Total Environment (2014) Sanderson, D.C.W., Cresswell, A., Allyson, J.D. and McConville, P. (1997) Review of Past Nuclear Accidents: Source Terms and Recorded Gamma-Ray Spectra. Project report to Department of enegy, UK, University of Glasgow, 2012

26 Louit et al., The Nuclear Reactor Accident at Windscale-October, 1957: Environmental Aspects, UKAEA T. Rabl, The Nuclear Disaster of Kyshtym 1957 and the Politics of the Cold War, Arcadia, 2012, no. 20 Lin WuHui, et al., Radioactive source terms for the Fukushima nuclear accident, SCIENCE CHINA, Earth Sciences, January 2016 Vol.59 No.1: Povinec, Hirose, Aoyama (Fukushima Accident, Radioactivity Impact on the Environment) Elsevier, 2016 K. Hirose, Fukushima Daiichi Nuclear Plant accident: Atmospheric and oceanic impacts over the five years, Jour. of Env. Radioactivity, 157 (2016)