Final answer:
The limit for occupational exposure to radiation that radiation workers must not exceed per year is 20 mSv. This guideline is set to minimize health risks such as cancer and genetic defects.
Step-by-step explanation:
Radiation workers must adhere to strict guidelines to protect their health from the risks associated with occupational exposure to radiation. The internationally accepted limit for radiation workers not to exceed per year is 20 mSv, as recommended by the International Commission on Radiological Protection (ICRP). This limit is designed to minimize the risk of cancer and genetic defects, both of which are long-term effects associated with high levels of radiation exposure. To ensure safety, radiation protection practices utilize methods such as shielding, maintaining distance, and reducing time of exposure.
For a specific scenario, a plumber at a nuclear power plant receiving a 30 mSv whole-body dose while repairing a valve would be at the maximum allowable exposure, and there would be an associated risk of radiation-induced health effects, which could be calculated relying on established risk coefficients.