The Nuclear Institute operates nationally via its branches.

The NI has nine regional branches, coincident with key nuclear industry locations. In addition, there is the YGN, which is spread across the Uk and has affiliations across Europe and the rest of the world. Meetings and activities are typically organised on a school year cycle, with recent meetings remaining listed on the site for reference until when the calendars for the next session are confirmed (typically between July and September).

• Central & South Scotland
  
• Central England Branch
  
• Cumbria Branch
• London Branch 
  
• Midlands Branch
  
• North East Branch
  
• North Scotland Branch
  
• North West Branch
  
• South East England Branch
  
• Western Branch
  
• YGN 
  
• South Africa Branch