radiological accidents in korea - gnssn home
TRANSCRIPT
Chang-Su Park, Ph. D.
Regional Workshop of Nuclear and Radiological Emergency Preparedness and Response
KINS, South Korea, June 8~19, 2014
Radiological Accidents in Korea
Lecture D2-8
Radiological Accident
Typical Cause of Accidents
Examples of Radiological Accident
I
II
III
Contents
Definition
Radiological Accident
Abnormal status of radiation source, which can affect
life, health and wealth of public due to control failure
Dose limit
• Annual dose limit : 50 mSv(worker), 1 mSv(public)
• Emergency work : 500 mSv, for lifesaving : no limit
• Sheltering : 10 mSv/2 days
• Evacuation : 50 mSv/1 week
- Robbery, Loss, Damage
- Mal-function, Leakage, Wrong-usage
- Terror using radiation
Yearly
Statistics (~2010.12)
Type
Field
year 70’s 80’s 90’s 2000’s Total
event 4 18 22 21 65
Theft Loss Exposure Over TLD Contam. Control Etc Total
10 19 23 2 2 3 6 65
Organi. Education NDT Industrial Research Medical Sales Total
2 1 36 6 5 13 2 65
5
ACCIDENT
FAILURE TO USE
SURVEY METER
EQUIPMENT
FAILURE
NOT FOLLOWING
SAFETY PROCEDURES
LACK OF
REGULATORY CONTROL
NO SAFETY PROGRAM
POOR OR NO
TRAINING
Typical cause of Accidents
6
ACCIDENT
LACK OF
REGULATORY CONTROL
No or ineffective Regulatory body
• poor or absent authorization process
• lack of regular field inspection
• inadequate inspection follow up
Typical cause of Accidents
7
ACCIDENT POOR OR NO
TRAINING
Lack of training
• unqualified operators
• poor understanding of emergency procedures
• No re-fresher training
Typical cause of Accidents
8
ACCIDENT
NO SAFETY PROGRAM
No safety program
• Inadequate management
• Lack of safety culture
Typical cause of Accidents
9
ACCIDENT
NOT FOLLOWING
SAFETY PROCEDURES
Safety procedures
• lack of safety culture
• inadequate supervision
• lack of training
Typical cause of Accidents
10
ACCIDENT EQUIPMENT
FAILURE
Equipment failure
• lack of maintenance
• poor use of equipment
• using equipment beyond design limits
Typical cause of Accidents
11
ACCIDENT
FAILURE TO USE
SURVEY METER
Failure to use survey meter
• not enough or meters not functional
• inadequate training
• rushing
• lack of safety culture
Typical cause of Accidents
12
□ Date :1992.06.14 □ Source : Ir-192, 38 Ci
□ Story : Break of the remote controller’s wire. Radiation source
couldn’t return in the container, left in front guide tube. The
worker gripped the guide tube without recognition, then
was over-exposed.
□ Result : 540 mSv(whole), 54 Sv(finger), cut the two nodes of finger
NDT : Over-exposure (1)
13
□ Date :2003.01.09 □ Source : Ir-192, 49.5 Ci
□ Story : A worker operated the guide tube to fix the location of the
source without withdrawing of the source back to the
container. No alarm dosimeter & collimator & supervisor.
□ Result :
- 36 Gy for right finger
: skin hardening, erythema and
fever, pain on the right finger,
after 1 week.
- 0.02 Sv for W.B : no special
symptom
NDT : Over-exposure (2)
14
□ Date :2004.03.18 □ Source : Ir-192, 43 Ci
□ Story : A worker operated without recognition about the
malfunction of alarm meter. Contact to the source 40 times
during 2 hours. Actual exposure time is 3 minutes.
□ Result : Burn and necrosis on hand
NDT : Over-exposure (3)
15
□ Date :1989.04. □ Source : NDT irradiator 2 EA
□ Story : The truck was stolen, which was parked without control.
The devices were mis-understood as expensive things.
Sources were returned by media which informed its danger.
NDT : Loss (1)
□ Date :1998.09.29 □ Place : Jinhae, Kyungnam
□ Story : On the driving with the truck loading irradiators, the
device was dropped on the road and lost.
□ Date :1998.11.13 □ Source : NDT irradiator
□ Story : After tiring night work, the worker forgot the irradiator left
on the parking place. Finally, open to the media and
found the device by public report.
16
□ Date :2000.02. □ Place : Ulsan
□ Story : The device was not stored in the designated box. When
rear trunk door of a driving ban was opened, the device
dropped on the road. Withdrew by police and media notice.
NDT : Loss (2)
□ Date :2000.02. □ Place : Pyungtaek
□ Story : The truck was stolen, which was parked without control.
17
□ Date :2009.02.06 □ Place : Gwangju
□ Story : The worker fell on the step. GPS location tracker was
broken away. In the meantime to bring the sticking
tape, a taxi driver stole the device.
NDT : Loss (3)
□ Date :2010.09.13 □ Place : Incheon
□ Story : A scrap collector stole the device left by workers.
18
□ Date :2000.11.22 □ Source : Ir-192, ~20 Ci
□ Place : Ulsan office for NDT
□ Story : The NDT source was stuck in the guide tube. The worker
thought he can pick out the source after grind the tube, and
ground the end of tube. The tube and source capsule were
broken, the powder of the source was spread. The worker
walk out to the road with contaminated clothes and shoes,
without recognition.
NDT – Contamination
Grind point
19
□ Result : Contamination was spread to the office and road. ~ 80 men
were involved to settle the situation. The max. dose rate
on the road is ~ 200 times of natural level.
NDT – Contamination
Accident place
20
□ Decon. : The broken source was collected with special designed
transport container. The near road and ground were
decontaminated and waste managed (total 200 L drum 84
ea, 50 L drum 33 ea). Contamination test and health check
for the near habitants were performed.
NDT – Contamination
□ Cost : Waste management ~ 20,000 $, the other settlement ~ 60,000 $,
for the habitants ~ 10,000 $
21
□ Date :2001.06.09 □ Source : Co-60, 20 mCi (level gauge)
□ Story : In a steel-work, the RI source of level gauge was lost, the
professional team of ministry and KINS searched the source
during 2 weeks with portable detector 36 EA, GPS, 120 men.
On the further survey with police and media during 3 mons.
Failed for the withdraw.
Industrial Source (1)
22
□ Date :2003.03.05 □ Source : Cs-137, 15 mCi (location sensor)
□ Story : Location sensor for transparent device, the source was
borrowed illegally to other company. On the returning
source to owner, source was lost on parking place.
Industrial Source (2)
□ Result : After 3 days, source was found in garage basket by cleaner
23
Industrial Source (3)
□ Date :2012.08.31 □ Source : Am-241/Be, 100 mCi (moisture gauge)
□ Place : Glass plant at Busan
□ Story : On the replacing work, the guide pipe was eliminated with
the source. The source was found after several months.
Guide pipe
24
□ Date :2009.07.24 □ Source : Am-241 (thickness gauge)
□ Place : A rolling plant at Sihung, Gyungi
□ Result : Damage of thickness gauge. The integrity of the source
and holder was maintained.
Industrial – Fire Accident (1)
25
□ Date :2010.11.29 □ Source : Cs-137 (flow gauge)
□ Place : A chemical plant at Ulsan
□ Result : Damage of flow gauge. The integrity of the source
and holder was maintained.
Industrial – Fire Accident (2)
26
□ Date :1976.11.
□ Place : Nuclear Research Institute (Seoul)
□ Source : Co-60, 0.1 PBq
□ Story : A student entered the irradiation room alone, to
experiment for radiation effect to chemical compound,
without recognition about opening of the source due to
safety lock problem.
□ Result : After irradiation, he felt
vomiting, transported to
the hospital and died in
treatment after 3 weeks.
Radiation Facility (1)
27
□ Date :1999.02.20 □ Source : X-ray generator (165 keV/5 mA)
□ Story : During NDT work for welding point on a airplane wing,
Forgot check of automatic switch off failure after set time
due to malfunctioned timer. So, the worker was over-
exposed at 5 cm in 2~3 min & at 120 cm in 4~5 min.
□ Result : 1130 mSv(whole), 55 Gy(hand), ulcers on the hand
Radiation Facility (2)
Medical Source – Terror
□ Date :1998.11.09 □ Place : Korea Cancer Center Hospital
□ Source : Cs-137(598 mCi) tube 17 ea, Ir-192(61 mCi) seed 292 ea
□ Story : A doctor stole and hid the source under the seat of a nurse’s
car with a intention for revenge to whom has an affair with
him. Report about the stolen source to police.
□ Result : Dose rate at seat is 22 mSv/h.
No exposed people. The doctor
was arrested.
□ Meaning : The only case for terror in
Korea, which has an objective
to attack the other person.
29
Household
□ Date :2012. □ Source : Co-60
□ Story : Contaminated wire material(SUS 4mm) were imported
from China and made to dish stand product. Civil complaint
about the radiation emitted from the product.
□ Result : 5~20 Sv/h at 1 cm. Total 1,450 ea recalled and ~600 ea were
found to be contaminated. Managed waste drum ~20 ea(200 L).
30
Road Contamination
□ Story : Metal scrap which contains Cs-137 were used to install the
asphalt road. Public report about the high dose-rate on the
road. Total 4 cases in Korea. Survey on the road. Drilling of
asphalt sample and analyzed.
□ Result : Little public health effect. Partial remove and waste manage.
31
Fallen Plane
□ Date :2012.06.29 □ Source : Sr-90, 50~500 Ci
□ Story : An helicopter of US Navy was fallen on the ground. The
wreckage were collected. Surveyed the site if radioactive
source was remained, which is used to IBIS(In-flight Blade
Inspection System), and Ice detector.
32
False Alarm
□ Date :2011.10. □ Source : None
□ Story : A shielding board which had a sticker for radiation alert,
was fallen on the bridge. (Only shield, No source)
□ Result : Close the bridge traffic completely for 3 hours.
