High-radiation-exposure tasks in Korean pressurized heavy-water reactors.

Area of Science:

• Nuclear Engineering
• Radiation Protection
• Occupational Health

Background:

• Pressurized heavy-water reactors (PHWRs) are a significant part of South Korea's nuclear energy infrastructure.
• Understanding occupational radiation exposure is crucial for worker safety in nuclear facilities.
• Previous analyses have not specifically detailed high-exposure tasks within Korean PHWRs.

Purpose of the Study:

• To analyze occupational radiation doses in Korean PHWRs.
• To identify specific tasks associated with high radiation exposure.
• To provide data for optimizing radiological protection strategies.

Main Methods:

• Analysis of occupational dose data from Korean PHWRs.
• Normalization of radiation dose by unit time to identify high-exposure tasks.
• Identification of specific maintenance activities contributing to elevated doses.

Main Results:

• The average individual occupational dose in Korean PHWRs is below regulatory limits for workers and the public.
• Certain tasks, including end-fitting lapping, delayed neutron tube work, and fuel channel fixed-end changes, were identified as high-radiation-exposure activities.
• A subset of workers received doses higher than the average, primarily during planned maintenance.

Conclusions:

• While overall doses are low, targeted radiation protection measures are necessary for specific high-dose tasks in Korean PHWRs.
• Prioritizing protection for identified high-exposure tasks can effectively optimize radiological protection and reduce worker doses.
• Further research into task-specific shielding and procedure optimization is recommended.