Which pair correctly represents the NEWS dose limits?

Which pair correctly represents the NEWS dose limits?

• A. 50 mSv per year and 100 mSv over five years
• B. 100 mSv per year and 200 mSv over five years
• C. 25 mSv per year and 125 mSv over five years
• D. 75 mSv per year and 150 mSv over five years

Answer: (A)

Occupational radiation dose limits are set to protect workers by controlling both annual exposure and the total exposure accumulated over a multi-year period. The NEWS standard specifies 50 mSv in any single year and 100 mSv in a five-year period. The correct pair matches these limits exactly: 50 mSv per year and 100 mSv over five years. If a choice implied 100 mSv in one year, that would exceed the yearly cap; if a choice implied more than 100 mSv over five years, it would exceed the five-year limit. The other options violate one of those two constraints, so they’re not acceptable.

Occupational radiation dose limits are set to protect workers by controlling both annual exposure and the total exposure accumulated over a multi-year period. The NEWS standard specifies 50 mSv in any single year and 100 mSv in a five-year period. The correct pair matches these limits exactly: 50 mSv per year and 100 mSv over five years. If a choice implied 100 mSv in one year, that would exceed the yearly cap; if a choice implied more than 100 mSv over five years, it would exceed the five-year limit. The other options violate one of those two constraints, so they’re not acceptable.