iaea international atomic energy agency overview of industrial radiography sources and accidents day...

IAEAInternational Atomic Energy Agency

Overview of Industrial Radiography Sources and

Accidents

Day 5 – Lecture 3

IAEA 2

To understand:-

• the applications of industrial radiography

• the potential for accidents during the use of industrial radiography radiation sources.

Objectives

IAEA 3

• The beneficial uses of ionizing radiation as used in industrial radiography practices

• The potential harmful effects due to the lack of and/or effectiveness of an adequate and appropriate radiation safety program

• The consequences of radiological accidents

Contents

IAEA 4

Industrial radiography is:-

• a process of non-destructive testing for examining the quality of a component or product;

What is Industrial Radiography?

• most often utilized for quality control of metal fabrication for the oil/gas industry;

• also used to test a range of other products.

IAEA 5

Imaging Principles

IAEA 6

• the types of radionuclides and activities used;

• work environments, that may range from clean laboratories to fabrication workshops and mining environments;

• equipment design and the work procedures that are essential to protect both the radiation worker and the public.

Overview of Industrial Radiography Equipment

Knowledge is required of:-

• the devices that use ionizing radiation from radiation sources (radioactive substances and x-ray devices) for industrial radiography;

IAEA 7

• Roentgen discovers x-rays in 1895

• Early x-ray tubes were unreliable

• Vacuum x-ray tube and heated filament (Coolidge-1913)

• 200kVp achieved in 1922

History

IAEA 8

• 1930s and 1940s 226Ra was used.

• 60Co and 192Ir after World War II

History (cont)

IAEA 9

Common•gamma source projectors•directional x-ray•panoramic x-ray•x-ray crawlers•gamma crawlers•crawler control sources

Uncommon•betatron•linear accelerator•neutron radiography•torch devices•fluoroscopy

Types of Industrial Radiography Equipment

IAEA 10

Has three main components:-

• x-ray tube assembly;

• x-ray control panel;

• high tension (HT) cables.

X-ray Equipment

IAEA 11

Special Considerations

• survey meters with appropriate response

• operator training

• shielding

Betatron

IAEA 12

Special applications

• on-shore pipelines

• off-shore pipelines (on a barge)

• remotely controlled with a separate ‘control’ source, typically 137Cs.

Gamma crawler equipment

IAEA

Half Value Layer (cms) Tenth Value Layer (cms) Isotope

Lead Iron Concrete Lead Iron Concrete 192Ir 0.6 1.3 4.6 2.0 4.3 14.7

60Co 1.2 2.0 6.6 4.0 6.9 20.6

169Yb 0.26 0.95 0.29 1.8 75Se 0.11 0.8 3.0 0.475 2.75 9.0

Radioactive Sources and some properties

IAEA

Projector-type radiography equipment

IAEA 15

Source containers must comply with recognized standards to ensure that exposures to users and the public are kept As Low As Reasonable Achievable.

The shielding of source containers must remain intact following any credible accident or incident. The shielding of this container (right) remained intact following a severe fire at the licensed premises.

Source containers

IAEA 16

Fluoroscopy

IAEA 17

• 48 industrial radiography accidents1 were reported to the US Nuclear Regulatory Commission between 1971 and1980.

• Severe injuries and a number of deaths have since been reported and investigated.

Industrial Radiography Accidents

1involving doses greater than 50 mGy to the whole body or 750 mGy to a part of the body. (Ref: NUREG/BR-0024). Many accidents may go unreported because those responsible fear the legal consequences.

IAEA

•IAEA Safety Report Lessons Learned from Accidents in Industrial Radiography. Series No.7:-• 43 cases; 9 involving the public or other non-radiation workers.

Industrial Radiography Accidents (cont)

IAEA 19

• 185 GBq 192Ir in shirt pocket for 90 minutes

• estimated skin dose of 30 Gy; whole body as 2-5 Gy


Severe injuries to a non-radiation worker resulting from the radiography worker failing to use a survey meter to confirm the source had been returned to the shielded container.

Day 15

IAEA 20

137Cs industrial radiography source; Argentina 1968


Poor source security leading to severe injuries and death

IAEA 21

137Cs industrial radiography source; Argentina 1968


Poor source security leading to severe injuries and death

Doses• 17000 Gy (localized)• 1 - 8 Gy (internal organs)• 0.6 Gy (head)

IAEA 22

1.37 TBq 192Ir.

2 days after accident; blister on upper thigh.

Yanango, Peru 1999


IAEA 23

Source not properly secured. Loss not apparent for 6 hours.

Skin dose at 1cm estimated at 10 kGy; right leg amputated. The worker’s wife and two children were also exposed.


IAEA 24

• Severe deterministic effects death, loss of limbs, erythema

Consequences of Accidents

• Increased stochastic risk fatal cancer

• Environmental contamination• Social & economic consequences

IAEA 25

•Causes identified as contributing to accidents:

Causes of Accidents

• Lack of or inadequate regulatory framework authorization inspection enforcement

• Lack of or inadequate safety culture management quality control training and qualifications of workers

IAEA 26

ACCIDENT

Failure to use survey meter

Equipment failure

Safety procedures not followed

Regulatory control lacking or

inadequate

Lack of safety program

Inadequate or lack of training

Causes of Accidents (cont)

IAEA 27

ACCIDENT

Regulatory control lacking or

inadequate


The Regulatory Authority has inadequate:-• authorization processes;• field inspections;• inspection follow up.

IAEA 28

ACCIDENT Inadequate or lack of training


Lack of training (and ongoing training) results in:-• unqualified and poorly instructed workers;• poor or no understanding of emergency procedures

IAEA 29

ACCIDENT

Lack of safety program


No safety program• inadequate management• lack of safety culture

IAEA 30

ACCIDENT

Safety procedures not followed


Safety procedures not followed indicates:-• lack of safety culture• inadequate supervision• lack of training

IAEA 31

ACCIDENTEquipment failure


Equipment failure indicates:-• lack of manufacturer’s recommended maintenance;• poor use of equipment;• equipment being used beyond design limits

IAEA 32

ACCIDENT

Failure to use survey meter


Failure to use survey meter indicates-• insufficient and/or non-functioning meters;• inadequate user safety training;• hurrying to complete the work (employer pressure);• lack of safety culture.

IAEA 33

• maintenance;• control.

Safe operation requires:• training;

Safe use of Radiation Sources

Radiation Sources:• are widely used;

SAFETY CULTURE}

• provide substantial benefits; but• can cause harmful effects (injury or death).

IAEA 34

the RISKS

BENEFITSshould outweigh

Safe use of Radiation Sources (cont)

IAEA 35

• IAEA, International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources, Safety Series No. 115, Vienna (1996).

• IAEA, Organization and Implementation of a National Regulatory Infrastructure Governing Protection against Ionizing Radiation and the Safety of Radiation Sources, IAEA-TECDOC-1067, Vienna (1999).

• IAEA, Lessons learned from accidents in industrial radiography, (reports in) Safety Reports Series.

• IAEA, Accident reports.

References

IAEA 36

•Consider the following industrial radiography equipment; portable x-ray; fixed x-ray; fixed gamma; portable gamma.

Exercise

• Which has the greatest potential to cause serious harm to the user and to the public?

• Why?

iaea international atomic energy agency overview of industrial radiography sources and accidents day...

Documents