Question: A radiation worker is subject to a dose of 50 mrad/h of protons for on

Question

Question: A radiation worker is subject to a dose of 50 mrad/h of protons for one 40 h work week. How many times the yearly allowable effective dose did she receive?

HINTS:

To obtain the effective dose, multiply the dose rate by the time in hours and the quality factor . You then have to divide this by the allowed dose for a radiation worker per year.

1 Gy = the amount of radiation which deposits energy at a rate of 1.00 J/kg = 100 rad

The absorbed dose clearly depends on the type of radiation, its energy, and the properties of the material itself, for example its density. If they are both subject to same radiation to their whole body, a 100 kg person will receive twce as much energy deposited and damage as a 50 kg person. However they both have the same energy deposited and damage per kg.

The absorbed dose clearly is not the most meaningful quantity since it does not reflect the differing amounts of damage done by different particle types with different energies.

Quality factor for types of radiation

TYPE QF X- and -rays ~1 -rays (electrons) ~1 Protons 1 Neutrons 3-10 's and heavy ions 10-20

The relative biological effectiveness (RBE) or quality factor (QF) of a given radiation is used to convert dose into effective dose, which is measured in rems or or sieverts (Sv).

effective dose (rem) = dose (rad) x QF

effective dose (Sv) = dose (Gy) x QF

and it follows that 1 Sv = 100 rem. Once more the Sv is the accepted SI unit, but rems are often used.

Note that a slow moving does 20 times the damage per rad as for example a fast proton.

Exposure (Sv) Exposure (rem) Significance 3.5 Sv 350 rem 50% morbidity (death) 1.0 - 3.5 Sv 100-350 rem possible health consequences 50 mSv - 1 Sv 5-100 rem medical intervention may be required 50 mSv/y 5 rem/y radiation worker dose limit 5 mSv/y 500 mrem/y non radiation worker permissable dose 2 mSv/y 200 mrem/y normal dose 1 mSv/y 100 mrem/y natural background

Explanation / Answer

Here the effective dose can be calculated by simple concept :

Effective dose = DOSE RATE xHours

ED = 50 mrad/hours x 40 hours

ED = 6 rads

This is about 6 times that worked allowed exposure for radiations worker.

Related Questions

Navigate

• Browse (All)
• Browse Q
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.