Q34.  What is air activity? How it is measured?

A.      If there is a presence of radioactive particles, in air, the air is said to be active. Air activity is measured

          in Bq/m³ or UUC/m³.

Q35. When respirator, gas mask and fresh air lines are used and why?

A.    Respirators are used when DAC is more than 1 and up to 10 DAC/hr. Gas masks are used up to 50 DAC/hr. Fresh air line is used for more than 20 DAC/hr. As per specification the above values are fixed.

Q36. When one using FAL in cell feels has not getting air, what he should do?

A.     If one is not getting air while using FAL, he should come out immediately.

Q37. How do you check that respirator is leak tight?

A.    After fitting on the face, close the filter with the palm and see that not air is available for breathing. If air leak is observed through the sides just stop till fitting is proper.

Q38. When plastic suit, double gloves or double boiler suits are used?

A.     Plastic suit, double boiler suit, double gloves are used where heavy contamination chances are/

Q39. If a part shows 200mr, what precautions you will take to carry it or repairing it?

A.    A       If a part shows 200 mr  then it will be decontaminated first as low as possible, if health physics permits then it will be carried otherwise the part will be repaired there only with hand gloves, spreading polythene sheet on ground etc and wearing half mask if required.

Q40. What is the difference between radiation and decontamination?

A.   Radiation is emission of Alpha, Beta and Gamma particles which can be shielded and stopped. Decontamination is removal of radioactive particles from body by cleaning.

Q41. How contamination is checked and washed?

A.    A.     Contamination can be checked by Alpha and Beta gamma monitor. Contamination is measured in CPS. By washing hands with detergents, contamination can be removed, chemicals like Soap EDTA, Citric acid, KmNo4, dilute H₂SO₄ (0.1 moler)

Q42. If radioactive liquid falls on ground while carrying a part, what you will do before calling health

         physics?

A.   If radioactive liquid falls on ground, spreading of liquid should be prevented by covering cotton waste and HP should be called and control room is also be informed.

Q43. Why urine samples and whole body counting are taken up? AT what frequency?

        A.     Urine samples and whole body counting are performed for measuring the internal exposure. Both are done once in a year.

Q44. Why plant stack is so high?

A.     Plant stack is kept high for dilution of air activity and prevention of recirculation of active air in plant.

Q45. How much dose a radiation worker can receive in a fortnight and in a year? How it is controlled?

A.     Radiation worker can be exposed in a) monthly 20mSv/200 mr, b) monthly exposure by authorizing by section supdt. – 40mSv/400 mr, c) monthly exposure authorizing by plant supdt. – 80mSv/800 mr, (consulting with HP), d) Quarterly exposure limit 1 R , e) yearly  2 R, 2.5 R also be given with the PS authorization.