License flow for use of nuclear material.

Transcription

1 Figure 2.1. License flow for use of nuclear material. Figure 2.2. License flow for the manufacturing business. 1

2 Figure 2.3. Major legislations and guides governing the safety regulation of fabrication business or utilization of nuclear fuel material 2

3 Figure 3.1. General map of Japan 3

4 Figure 3.2. Regional map of Ibaraki Prefecture. The circle represents the 10 km area within which about 310,000 people were recommended to stay indoors. 4

5 Figure 3.3. Location of JCO site (JCO Tokai Plant). JCO facilities Figure 3.4. Plan of the JCO site with location of monitoring points (circled numbers) 5

6 Figure 3.5. Layout in the JCO conversion test building where the accident took place. 6

7 Figure 3.6. Cross-section of the precipitation tank indicating dimensions (in mm). 7

8 Figure 3.7. Process flow of producing uranium dioxide or UNH in the CTB. 8

9 Figure 3.8. Production system licensed in 1984 for UO 2 and UNH in the CTB. 9

10 Figure 4.1. Changes of the production process of UNH solution in the CTB. 10

11 Figure 4.2. Production system of JOYO UO 2 in the period of Figure 4.3. Production system plan of JOYO UNH which was agreed between PNC and JCO on June 25,

12 Figure 4.4. Production system of UNH in the Joyo 4 th Campaign ( ). Figure 4.5. Production system of UNH in the JOYO 6 th Campaign (1993). 12

13 Figure 4.6. Production system of UNH in the JOYO 7 th Campaign ( ). Figure 4.7. Production system of JOYO UO 2 in the period of

14 Figure 4.8. Production system of UNH in September

15 CTB (behind the trees) Photo 5.1. Bird eye view of near the JCO site in Tokaimura, Ibaraki. 15

16 Photo 5.2. Stainless steel beaker. Photo 5.3. Precipitation tank 16

17 Photo 5.4. The CTB and the cooling tower for the precipitation tank. Photo 5.5. Working clothes for water draining. 17

18 Photo 5.6. Pipe connection to be broken (a snap shot). Hose Photo 5.7. The precipitation tank with a hose for injection of boric acid. 18

19 Wall B A C Floor W Figure 5.1 accident. Working situation of severely exposed three workers in the criticality Figure 5.2. Records of a gamma-ray monitor in the JCO facility. 19

20 Handhole NH 3 Uranyl nitrate Cooling water Total amount about 80 Liters Heater Figure 5.3. JCO. Sketch of the precipitation tank for discussion on the criticality provided by 20

21 Figure 5.4. indication. Chronological record of various meetings and centers and gamma-ray dose 21

22 Figure 5.5. Neutron and gamma-ray dose distribution map at JCO site at around 17:00, September

23 Figure 5.6. Locations of JCO, the Naka Fusion Research Establishment of JAERI (JAERI Naka) and Mitsubishi Nuclear Fuel (MNF). MP-1 and MP-2 indicate monitoring posts in the JAERI Naka. 23

24 Figure 5.7. Observed data with the neutron and gamma-ray monitors in MP-1 and MP-2 at the JAERI Naka site. Neutron dose equivalent rate (μsv/h) 10:36:16 on September Dose equivalent rate averaged over first two minutes: 0.11μSv/h Figure 5.8. Data of the neutron monitors of MP-1 and MP-2 for every 1 second. 1

25 Figure 5.9. Time dependence of released fission power. 2

26 Figure Simplified calculation model of the precipitation tank prepared in the night of accident (September 30) and balance of estimated reactivity change before and after the draining of cooling water. 3

27 Figure Detailed structural drawing of the precipitation tank (left) and the model prepared for calculation (right). Figure Operations of water drain and boric acid injection. 4

28 6:25 < 1μSv/h 6:12 Ar gas injection 6:02, October 1 65μSv/h Neutron dose equivalent rate Time Figure Record of decrease of neutron dose rate. 5

29 Figure 6.1. Local map indicating the area enclosed by the bold line, for which evacuation was implemented. The circle shows a 500 m radius from the CTB, and circled numbers indicate positions of radiation monitoring. 6

30 Figure 7.1. Procedures for establishing calculation geometry. (a) Upper: positions and postures recounted by the workers; lower: final estimation by NIRS. The position of left hand of Worker A is different from the upper model. (b) Behavior experiment at a mock-up facility. (c) Established geometry for computer simulation. Figure 7.2. γ-ray dose. Absorbed dose distributions in the skin of Worker A. (a) Neutron dose. (b) 7

31 Figure 7.3. Absorbed dose distributions of neutrons and γ rays in the trunk of Worker A. 8

32 Figure 7.4. Estimates of doses for the employees of JCO and its related companies, excluding the three heavily exposed workers. Figure 7.5. Estimates of doses for the emergency response personnel. 9

33 Figure 7.6. Model of the dose rate evolution. Figure 7.7. Fitting curves of the measured data. 10

34 Figure 7.8. Estimates of doses for the residents. Hitachi-city Indoor sheltering area Tokai-mura Naka-town Mito-city JR Joban Line Hitachinaka-city Figure 7.9. Locations of monitoring stations (denoted by red) around the JCO site. 11

35 Critical Care Traumatology Transplantation Medicine Burn NIRS Emergency Medicine Dermatology Surgery Health Physics Figure 8.1. Medical Network Council for Radiation Emergency. The Medical Network Council for Radiation Emergency was established as an advisory and supporting framework complementary to the NIRS s function in July Time Events Time after accident (min) Symptoms Worker A B C vomiting diarrhea vomiting nausea 10 : : : : 27 The Criticality Ambulance was called Ambulance arrived Workers were on the ambulance JCO loss of consciousness nausea 11 : : 07 Ambulance left Arrived at National Mito Hospital : 43 Left National Mito Hospital : 16 Helicopter left Mito Heliport : : 58 Helicopter arrived at Chiba Left Chiba Heliport nausea 15 : 25 Workers arrived at NIRS NIRS 290 Figure 8.2. Prodromal symptoms of acute radiation syndrome in these three workers. 12

36 30 25 White Blood Cell Worker A Worker B Worker C Lymphocyte G l Days postexposure G l Days postexposure G l Platelet Days postexposure G l Hemoglobin Days postexposure Figure 8.3. Hematologic data of the patients. (a) Peripheral blood counts of Workers A, B and C during the first 11 days are depicted with diamonds, rectangles and triangles, respectively. 13

37 G-CSF mpsl Water discharge > 10L/d from skin, GI tract PBSCT Day 1 Day 15 Day 29 Day 43 Day 57 Day 71 WBC Neu Lymph Figure 8.4. Clinical course of Worker A. G-CSF: granulocyte colony stimulating factor, mpsl: methyl prednisolone, PBSCT: peripheral blood stem cell transplantation, GI: gastrointestinal, WBC: white blood cells, Neu: neutrophils, Lymph: lymphocytes, G-CSF: granulocyte colony stimulating factor, mpsl: methyl prednisolone. Adapted and modified from Chiba S et al. Bone Marrow Transplant. 29: , 2002 and Futami S et al. pp , IN: International Symposium on The Criticality Accident in Tokaimura: Medical Aspects of Radiation Emergency (Proceedings). Tsuji H and Akashi M. (Editors) NIRS-M-146,

38 8~10GyEq WBC(/mm3) Neut. (/mm3) Lymph neutron CyA3mg/Kg/daydiv2 1mg/Kg/day Allogeneic 4mg/Kg mps PSL(mg/Kg/day) skin transplanta 2mg/Kg Allogeneic skin graft 10μg/Kg/day/civ μg/Kg/day/civ μg/Kg/day/civ ATG 2.5mg/kg 2days G-CSF CBT 2.08x10 7 TNC/kg Days post-transplantation Figure 8.5. Clinical course of Worker B. G-CSF: granulocyte colony stimulating factor, mpsl: methyl prednisolone, CBT: cord blood cell transplantation, WBC: white blood cells, Neu: neutrophils, Lymph: lymphocytes Adapted and modified from Nagayama H et al. Bone Marrow Transplant. 29, ,

39 GIT decontamination Pentoxifylline ( 10 2 /mm 3 ) G-CSF White Blood cells WBC Neu 0 Plt ( 10 4 /mm 3 ) Lymph ( 10 2 /mm 3 ) Absolute number of lymphocytes Platelets PLT 15U Plt Lymph 0 Day 0 Day5 Day17 Day29 Day40 Day52 Day63 Day75 Figure 8.6. Clinical course of Worker C. GIT: gastrointestinal tract, G-CSF: granulocyte colony stimulating factor, WBC: white blood cells, Neu: neutrophils, Plt: platelet, Lymph: lymphocytes 16

40 Reactivity ($) batch Uranyl nitrate solution 370 gu/l, 0.5N, 25 C Height 6 batch + 2l +4l 7 batch 1 st feed of 7th batch? Solution height (cm) Figure A.II.1. Results of reactivity calculation. Power (W) $ 2.5$ 2.0$ JCO : Flow Rate 0.5 L/min 1.5$ First pulse Fission Reactivity 6.14E $ 5.95E $ 5.78E $ 6.01E $ Time (s) Figure A.II.2. Calculated power at the first burst. 17

41 1.E+08 1.E+07 1st peak power 10MW (1.5$) 17MW (3.0$) Power(W) 1.E+06 1.E $ 1.E+04 1.E $ Time(sec) Figure A.II.3. Comparison of power profiles for different reactivity. Heater Power(kW) Compensated reactivity at initial temperature (reference temp. : 25 ) 2.7($) Temperature Power Observed Power Stop of cooling water circulation Elapsed Time in Plateau Part(hr) Solution Temperature( ) Figure A.II.4. Results of thermal simulation experiment. 18

42 Coolant Flow Rate(L/min) Total Energy Energy in Burst Inserted Reactivity($) Figure A.II.5. Results of optimum parameters survey by quasi-steady state method $, 0.375L/min Power(W) & Energy(J) Power(C) Energy(C) Power(E) Energy(E) Time (s) Figure A.II.6. Power profile for whole period calculated with quasi-steady state method. 19