Transcript Protection against sealed sources

 Sealed
sources are radioactive materials
encased or "sealed" inside metal or plastic
and can take many different forms, sizes and
shapes. All forms share some type of
encapsulation that prevents their radioactive
contents from leaking or dispersing, barring
tampering or a severe accident. In some
forms, the radioactive material is an inherent
part of the source and cannot be separated.
 Almost
all "sealed sources" can be handled
without concern that the radioactive
material will rub-off or be dispersed onto
hands or clothing. There is, however,
reason to be concerned about exposure to
the radiation emitted from the sealed
source. Sealed sources are not a significant
contamination
hazard
under
normal
conditions; however, they may present an
external exposure hazard.
 Plated
sources
In this form, the radioactive
material
coats
a
disk
or
planchette. This coating may be
covered, depending upon the
type of radiation, by mylar,
aluminum, steel, or plastic.
 Capsules
 In
this form, a capsule usually
made of metal surrounds the
radioactive
material.
These
sources are often placed onto the
end of metal or plastic handling
rods. Another example of a
capsule is when a mixture of
radioactive compounds is placed
into a container and welded or
sealed closed.
 Activated

metal
In this form, a metal wire or foil has been
exposed to a neutron flux to irradiate the metal
and create a radioactive isotope from the original
material. This form of sealed source may have a
plastic or epoxy coating to protect the activated
metal. In some instances, however, the metal is
not protected.
 Many
commonly used laboratory devices
also contain sealed sources, such as gas
chromatographs with electron capture
detectors, liquid scintillation detectors,
and static eliminators.
Sealed sources present an external radiation
hazard as opposed to a contamination hazard.
Sealed sources can emit any type of ionizing
radiation, including alpha particles, beta particles,
gamma rays, x-rays, or neutrons.
 1. Do not touch electroplated sources, as this may
result in the removal of the active material.
 2. Wear gloves when working with a plated or
deposited source.
 3. Monitor hands and fingers after handling a
plated or deposited source.
 4. Do not use handling tools in such a way as to
penetrate the surface of the source.
 5. Storage containers should not have material
that abrades the surface of the electroplated
sources.

 6.
Sealed Sources shall not be opened
under any circumstances!
 7.
Only authorized individuals shall
perform the repair and cleaning of sources.
The safety and handling precautions
furnished by the manufacturer shall be
maintained in a location that is readily
available to all workers and followed.
 8. Storage containers must be properly
labeled.
 The
equipment which may contain sources of
interest in this publication varies widely in
construction and application. Descriptions of
some of the main types of equipment are
provided below
 1.1.
Brachytherapy (therapy at a short
distance) is a term that is used to describe the
interstitial application of radioactive sources by
placing them directly in the tumor (e.g. breast,
prostate), in moulds (e.g. skin, rectum) or in
special applicators (e.g. vagina, cervix).
Originally, brachytherapy techniques involved
the use of individual needles or manual after
loading. Relatively low activity sources were
used in these applications. Historically, 226Ra
encapsulated in platinum in either needles or
tubes of a few mm in diameter and up to 5 cm
in length was used (Fig).
‫زراعة المواد النشطة في‬
‫الصدر‬
‫كبسوالت نشطة إشعاعياً‬
‫ُتغرس في موضع سرطان‬
‫البروستات‬
‫زراعة المواد النشطة داخل‬
‫الرحم‬

Emission of alpha particles (helium nucleus)
leads to pressure buildup in a sealed capsule. A
buildup of pressure may eventually damage the
encapsulation, resulting in a release of
radioactivity. Remote afterloading techniques
were developed in the 1970s. 226Ra was replaced
mainly by 137Cs and 60Co and more recently by
192Ir and 252Cf. These techniques involve the use
of machines which can contain a large number of
relatively low activity sources, but which taken
together represent a significant inventory stored
in a single, relatively transportable container. An
example of brachytherapy equipment is shown in
Fig. 3. This type of equipment typically contains
activities of up to 185 GBq (usually of 137Cs).
Remote afterloading equipment is used to
arrange sources into an appropriate configuration
and to transfer them either pneumatically or on
the end of a cable into the patient applicator.
 The
other principal medical application of sealed
sources is teletherapy, where a large source
(typically 60Co but possibly 137Cs) of several
hundred TBq is used, external to the body, to
irradiate a tumor. 60Co Teletherapy heads can
contain up to 500 TBq of activity. An example of
a 60Co unit is shown in Fig. 4.
 Sealed
radioactive sources are also used in
medicine for bone densitometry (241Am, 153Gd
and 125I), for whole blood irradiation (137Co,
60Co) and as gamma radiosurgery knives
(60Co).
 In
heavy industries such as steel foundries or
fabrication, portable, mobile or fixed
radiographic equipment incorporating various
radionuclides may be installed in purpose
built enclosures. Mobile or fixed installations
incorporate heavier shielding than portable
source housing
 Typical
industrial applications with their main
isotopes are shown below:
 (a) Industrial radiography: 6oCo, 192Ir, 75Se,
170Tm, 169Yb, 137Cs (historical); 241Am/Be,
252Cf (neutron radio-graphy);
(b) Moisture detectors: 241Am/Be, 137Cs,
226Ra/Be, 252Cf;
(c) Well logging: 241Am/Be, 137Cs;
(d) Gauges: 137Cs, 6oCo, 241Am, 85Kr,
90Sr(+90Y), 32P, 147Pm;
 (e)
Static eliminators: 241Am, 210Po, 226Ra;
 (f) Lightning rods: 241Am, 85Kr, 226Ra
(historical); (g) Dredgers: 60Co
 (h) X ray fluorescence analysis: 55Fe, 109Cd,
238Pu, 241Am, 57Co;
 (i) Calibration: 60Co, 137Cs;
 (j) Smoke detectors: 241Am, 239Pu.
is the use of ionizing radiation to view
objects in a way that cannot be seen
otherwise. It is not to be confused with the
use of ionizing radiation to change or modify
objects; radiography's purpose is strictly
viewing. Industrial radiography has grown
out of engineering, and is a major element
of nondestructive testing. It is a method of
inspecting materials for hidden flaws by
using the ability of short X-rays and gamma
rays to penetrate various materials. One way
to inspect materials for flaws is to utilize Xray computed tomography or Industrial
computed tomography scanning.
Gamma-ray image of intermodal cargo
container with stowaways
A portable wireless controlled battery
powered X-ray generator for use in nondestructive testing and security.
 For
example
 Soil moisture sensors measure the water
content in soil. A soil moisture probe is made
up of multiple soil moisture sensors.
A simple soil moisture sensor for
gardeners.

Nuclear logging was initially developed to
measure the natural gamma radiation emitted by
underground formations. However, the industry
quickly moved to logs that actively bombard
rocks with nuclear particles. The gamma ray log,
measuring the natural radioactivity. These logs
were important because they can be used in
cased wells (wells with production casing). WSI
quickly became part of Lane-Wells. During World
War II, the US Government gave a near wartime
monopoly on open-hole logging to Schlumberger,
and a monopoly on cased-hole logging to LaneWells Nuclear logs continued to evolve after the
war.


A nuclear density gauge is a tool used in petroleum
industry, as well as for mining and archaeology purposes. It
consists of a radiation source that emits a directed beam
of particles and a sensor that counts the received particles
that are either reflected by the test material or pass
through it. By calculating the percentage of particles that
return to the sensor, the gauge can be calibrated to
measure the density and inner structure of the test
material.
Different variants are used for different purposes. For
density analysis of very shallow objects such as roads or
walls, a gama source emitter such as 137Cesium is used to
produce gamma radiation. These isotopes are effective in
analyzing the top 10 inches (25 centimeters) with high
accuracy. 226Radium is used for depths of 328 yards (300
meters). Such instruments can help find underground caves
or identify locations with lower density that would make
tunnel construction hazardous.
 Static
eliminators may be used in research
laboratories as part of analytical balances,
or to neutralize static charges on
membrane filters.
These devices may
contain Po210, a radioactive material which
emits alpha radiation. These devices often
contain 500 microcuries of Po210. They are
often only useful for 1-2 years due to the
decay of the Po210, which has a half live of
only 138 days.

is a metal rod or metallic object mounted on top of
an elevated structure, such as a building, a ship, or
even a tree, electrically bonded using a wire
or electrical conductor to interface with ground or
"earth“ through an electrode, engineered to
protect the structure in the event of lightning
strike. If lightning hits the structure, it will
preferentially strike the rod and be conducted to
ground through the wire, instead of passing
through the structure, where it could start a fire or
cause electrocution. In a lightning protection
system, a lightning rod is a single component of the
system. The lightning rod requires a connection to
earth to perform its protective function. The main
attribute common to all lightning rods is that they
are all made of conductive materials
From article : 
the lightening preventers are “highly 
dangerous” and should not be touched.
They said that if someone comes across the
material they should not approach it.
The Radiological Protection Institute of 
Ireland said ”if handled they will cause
radioactive contamination to the person’s
hands and clothing with the possibly of
internal radioactive contamination. Close
proximity to these sources will result in a
person exceeding the annual radiation dose
limit in a matter of hours”.
If the radioactive sources are cut up or 
dismantled they could cause local
environmental contamination as well as
contamination of the person.
Speaking to TheJournal.ie David Dawson 
from the Radiological Protection Institute
of Ireland said the metal rods “may just
look like scrap metal, but on that metal are
tiny black squares which are highly
radioactive”.
He added: 
This material has a very high dose of 
radiation and is extremely hazardous to
the health of anyone who comes into
contact with them.
 X-ray
fluorescence (XRF) is the emission of
characteristic "secondary" (or fluorescent) Xrays from a material that has been excited by
bombarding with high-energy X-rays or gamma
rays. The phenomenon is widely used
for elemental analysis and chemical analysis,
particularly in the investigation of metals, glass
, ceramics and building materials, and for
research in geochemistry, forensic science
and archaeology.
 It
is a statutory requirement that all instruments
used for the designation and monitoring of
controlled or supervised areas are tested on a
regular basis.
 A calibration will determine the instruments
response to a range of well-defined radiations
under reference conditions. This provides the
user with evidence that the instrument’s
response is satisfactory. It will usually confirm
whether the response curve provided in the
manual or type test data is satisfactory for use.


A smoke detector is a device that senses smoke,
typically as an indicator of fire. Commercial and
residential security devices issue a signal to a fire
alarm control panel as part of a fire alarm system,
while household detectors, known as smoke alarms,
generally issue a local audible or visual alarm from
the detector itself.
Smoke detectors are typically housed in a diskshaped plastic enclosure about 150 millimetres (6 in)
in diameter and 25 millimetres (1 in) thick, but the
shape can vary by manufacturer or product line. Most
smoke detectors work either by optical detection
(photoelectric) or by physical process (ionization),
while others use both detection methods to increase
sensitivity to smoke.
 An
ionization smoke detector uses a
radioisotope such as americium-241 to
produce ionization in air; a difference due to
smoke is detected and an alarm is generated.
Ionization detectors are more sensitive to
the flaming stage of fires than optical
detectors, while optical detectors are more
sensitive to fires in the early smouldering
stage.[2]
 Radiography
is the use of ionizing
electromagnetic radiation such as X-rays to
view objects. Although not technically
radiographic techniques, imaging modalities
such as PET and MRI are sometimes grouped
in radiography because the radiology
department of hospitals handle all forms of
imaging.
 Radiography
started in 1895 with the
discovery of X-rays , a type of
electromagnetic radiation. Soon these
found various applications, from helping to
find shoes that fit, to the more lasting
medical uses.

X-rays were put to diagnostic use very early, before
the dangers of ionizing radiation were discovered.
The medical specialty of radiology grew up around
the new technology, and new diagnostic tests
involving X-rays were developed, it was natural for
the radiographers to be trained and adopt this new
technology.
This
happened
first
with
fluoroscopy,
computed
(1960s), and mammography

tomography
Ultrasound (1970s) and magnetic resonance
imaging (1980s) was added to the list of skills used
by radiographers because they are also medical
imaging, but these disciplines do not use ionizing
radiation or X-rays.
 Diagnostic
radiography involves the use of
both ionizing radiation and non-ionizing
radiation to create images for medical
diagnoses. The predominant test is still the Xray. X-rays are the second most commonly
used medical tests, after laboratory tests. This
application
is
known
as
diagnostic
radiography.
 Since
the body is made up of various
substances with differing densities, X-rays
can be used to reveal the internal structure
of the body on film by highlighting these
differences using attenuation, or the
absorption of X-ray photons by the denser
substances (like calcium-rich
bones).
Medical
diagnostic
radiography
is
undertaken
by
a
specially
trained
professional called a diagnostic radiographer
in the UK, or a radiologic technologist in the
USA.
 Mammography
is an X-ray examination of
breasts and other soft tissues. This has been
used mostly on women to screen for breast
cancer, but is also used to view male breasts,
and used in conjunction with a radiologist or a
surgeon to localise suspicious tissues before a
biopsy or a lumpectomy.