Emergency:Lost of Control Of Unsealed Source

-        Hi everyone!! This time we would like to share about the 3 sources of radiation emergencies. The radiation emergencies include lost control of sealed source,lost control of unsealed source and conventional emergency like fire. Yet, we are going to focus on the lost control of unsealed source.

  Before that, what is unselaed source? Unsealed source is a source of Ionising Radiation in the form of Radioactive material which is not encapsulated or otherwise contained.

- The implication is that unsealed radioactive material can move around and if uncontrolled would lead to Contamination .

According to BSS (basic  safety standard) , we have to follow these steps to handle the lost control of unsealed source: 

•  Requirement 43:  The government shall ensure that an integrated and coordinated emergency management system is established and maintained.
•  The procedures should be clear, concise and unambiguous and shall be posted visibly in places where their need is anticipated.
• An emergency plan shall, as a minimum, list/describe:

1.  predictable incidents and accidents and measures to deal with them;
2.  the persons responsible for taking actions, with full contact details;
3.  the responsibilities of individual personnel in emergency procedures (nuclear medicine physicians, medical physicists, nuclear medicine technologists, etc.);
4.  equipment and tools necessary to carry out the emergency procedures;
5.  training and periodic rehearsal;
6.  recording and reporting system;
7.  immediate measures to avoid unnecessary radiation doses to patients, staff and public;
8.  measures to prevent access of persons to the affected area; and
9.  measures to prevent spread of contamination.

Decontamination process

A)   Small Amounts of Radioactive Spills

•     Use protective clothing and disposable gloves
•     Quickly blot the spill with an absorbent pad to keep it from spreading.
•      A plastic bag to hold contaminated items shall be available as well as some damp paper towels
•      Remove the pad from the spill
•      Wipe with a towel from the edge of the contaminated area toward the centre
•     Dry the area and perform a wipe test
•      Continue the cycle of cleaning and wipe testing until the wipe sample indicates that the spill is cleaned

  B)  Large Amounts of Radioactive Spills

•      The RPO should immediately be informed and directly supervise the clean-up.
•      Absorbent pads may be thrown over the spill to prevent further spread of contamination.
•      All people not involved in the spill should leave the area immediately.
•       All people involved in the spill should be monitored for contamination when leaving the room.
•      If clothing is contaminated it should be removed and placed in a plastic bag labeled ’RADIOACTIVE’.
•      If contamination of skin occurs, the area should immediately be washed.
•     If contamination of eye occurs, flush with large quantities of water.

Facilities Design in Diagnostic Imaging

Hi there!!! Today we will share about the facilities design in diagnostic imaging. Advances in X-ray imaging technology, together with developments in digital technology have had a significant impact on the practice of radiology. This includes improvements in image quality, reductions in dose and a broader range of available applications resulting in better patient diagnosis and treatment. However, the basic principles of X-ray image formation and the risks associated with X-ray exposures remain unchanged. X-rays have the potential for damaging healthy cells and tissues, and therefore all medical procedures employing X-ray equipment must be carefully managed. The need for radiation protection exists because exposure to ionizing radiation can result in deleterious effects that manifest themselves not only in the exposed individuals but in their descendants as well. Let’s find out more about this…

MACHINE & APPLICATION OF DIAGNOSTIC IMAGING FACILITIES

As a discipline and in its widest sense, it is part of biological imaging and incorporates radiology which uses the imaging technologies of X-ray radiography, magnetic resonance imaging, medical ultrasonography or ultrasound, endoscopy, elastography, tactile imaging, thermography, medical photography and nuclear medicine functional imaging techniques as positron emission tomography (PET) and Single-photon emission computed tomography (SPECT).

General Xray

MRI Machine

CT Scan Machine

Nuclear Medcine Machine

Ultrasound Machine

SAFETY CONSIDERATIONS

• Except for those persons whose presence is essential, all persons must leave the room when the irradiation is carried out.
• Personnel must, at all times, keep as far away from the X-ray beam as practicable. Direct radiation exposure of personnel by the primary X-ray beam must never be allowed.
• Deliberate irradiation of an individual for training purposes or equipment evaluation must never occur.
• All personnel must use available protective devices provided by the institute.
• All personal dosimetry records must be maintained for the lifetime of the facility.
• All entrance doors to an X-ray room should be kept closed while a patient is in the room and must be closed while making an X-ray exposure.
• X-ray machines which are energized and ready to produce radiation must not be left unattended.

SHIELDING

DIAGNOSTIC IMAGING ROOM DESIGN AND LAYOUT

Do you know that  LEAD is the dominant material used in x-ray and radiation shielding applications?? Lead shielding refers to the use of lead to shield you from scatter radiation. Lead and some of its alloys are generally the most cost effective radiation shielding materials to protect against the effects of gamma rays and x-rays. The properties of lead shielding which make it an excellent shielding material are its density, high atomic number, high level of stability, ease of fabrication, high degree of flexibility in application, and its availability.

Data required include consideration of: 

•  Type of X Ray equipment-
  
  • Where the X Ray beam will be directed.
  • The number and type of procedures performed.
  • The location of the radiographer (operator).
  • The energy (kVp) of the X Rays.
•  Positioning
  
  • Distances are measured from the equipment (inverse square law will affect dose).
  • The directions the direct (primary) X Ray beam will be used depend on the position and orientation

How we manage the source?

 

RADIATION SOURCE MANANGEMENT

From our previous post we already mention about International Commission on Radiological Protection and its big function in radiation protection specially. ICRP proposed a system of radiation protection with its three principles of justification, optimization and individual dose limitation in publication

① The principle of JUSTIFICATION: Any decision that alters the radiation exposure situation should do more good than harm

② The principle of OPTIMIZATION of protection: the likelihood of incurring exposures, the number of people exposed, and the magnitude of their individual doses should all be kept as low as reasonably achievable, taking into account economic and societal factors.

③ The principle of application of DOSE LIMITS: The total dose to any individual from regulated sources in planned exposure situations other than medical exposure of patients should not exceed the appropriate limits recommended by the Commission.