Radiation Symbol SAFE STORAGE OF SOURCE Obtain legal
Radiation Symbol
SAFE STORAGE OF SOURCE Obtain legal approval to store and handle isotopes Use occupancy less area for storage Follow suggested design of storage, otherwise obtain competent approved alternative design Store radiography cameras / sources in pit in a separate storage room Keep the storage room under lock & key always Continue…
Continued. SAFE STORAGE OF SOURCE Check proper storage of source inside camera after every use. Use survey meter check radiation leakage Post Warning signs along with radiation symbol Operator shall maintain log book to record usage of the equipment
STORAGE OF RADIO ACTIVE CAMERA & SOURCE Layout Plan for Radiography Camera Store Room
LOG BOOK The following information to logged: Date & time of taking the source with camera Type & strength of sources Model & serial no. of camera Name of the radiographer Location of use Type & number of exposure Duration of use Date & time of return of the source with camera
Permissible Leakage Level of Camera Measurement Distance 5 cm from Surface 1 m from source position Average m. R/hr 20 2 Maximum m. R/hr 100 10
Safe Work Practices Carry out Radiography operations during No occupancy times Far away from workplace Night hours Less occupancy times Holidays Lunch Hours Make wire fence / brick enclosure for regular radiography area.
Transportation of sources Check source pencil is securely immobilized and locked in camera Inform BARC (Baba Atomic Research Centre), Mumbai, if damage to the cameras during transport, non-receipt of consignment in the reasonable time Avoid Maintenance and servicing of radiographic equipment without consulting the Radiological Safety Officer (RSO)
Safe Work Practices Cordoning the radiography area Calculate the safe cordoning distance Make barricades with warning signs Make reflective signs during night time operation Use survey meter to check radiation level at cordoned boundaries Ensure adequate illumination
Example Calculation Iridium-192 of 20 curie is used in open field of Occasional Occupancy for a period of 5 hours per week. Calculate the cordon off distance. Take Public dose limit as 2 m. R/week and B as 40. Cordon off distance in the direction of primary beam: D 2 = (K x A x W) T / P = (500 x 20 x 5) (1/16) / 2 D = 39. 5 m Cordon off distance in the directions other than primary beam direction: D 2 = (K x A x W)T / (P x B) = (500 x 20 x 5) (1/16) / (2 X 40) D = 6. 25 m
Cordon off distances for Open Field Radiography (Panoramic Exposure) (Iridium – 192) Source Strength Nature of Human Occupancy Work Load 5 10 15 20 30 hrs/week hrs/week Cordon off distance (m) 5 Curie 8 Curie 10 Curie Full 37 52 66 74 93 Partial 18 26 33 36 47 Occasional 10 13 17 18 24 Full 47 65 80 94 122 Partial 24 33 40 48 56 Occasional 12 16 20 24 28 Full 53 74 90 100 126 Partial 26 37 45 52 63 Occasional 13 19 22 26 31
Occupancy Factor for open field radiography Nature of Human Occupancy Full Occupancy Factor 1 Partial 1/4 Occasional 1/16
Ensure Safe Work Practices Following Industrial Radiography Information form (Format attached) Radiographer carries film badge / dosimeter Radiographers dose limit is below the permissible limit ( chart shown in next slide) Radiographers follows the safety instruction strictly Continue…. .
Ensure Safe Work Practices Continued. . Operators undergoes regular medical check up as per BARC Source is not handled by hand When source is expose it is advised to Stand behind buildings / steel / shielding materials Stay away from source of radiation Limit exposure for particular operator /day Make use of full length cable provided between radiographic equipment and the control unit / panel Operator aware about his dose records and reports of periodic medical exams
Safe Work Practices Make collimated exposure Avoid panoramic exposure Use full length camera Use suitable supporting and fastening devises Camera operation behind barriers Plan well the activities to limit exposure time. Use radiation survey meter to check the source returns to safe position
Maximum Permissible Dose Limit Organ Dose Limit for adult radiography workmen (rems/Year) Dose Limit for Public (rems/Year) Bone morrow, Eye Lens 5 0. 5 Skin, Bones & Thyroid Hands, Forearms, Feet and Ankles Other Organs 30 3 75 7. 5 15 1. 5 Cumulative dose for an occupational worker can be (N-18) Rems, N is the age of the radiography workmen. On an average it shall not exceed 100 milli Rems per week, 1 ¼ Rems per calendar quarter and 5 Rems per year. 250 to 400 RADs are sufficient to make it fatal in 50% of the cases within 30 days. With 50 to 100 RADs, the skin will turn reddish and a little higher dose will make the hair fall.
YOUR TIME TO GET CLARIFIED ANY Q ?
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