Los Alamos National Labs with logo 2021

Primary Physics

Design of nuclear weapon primaries and performance and reliability assessments

Contact Us  

  • Deputy Group Leader
  • Cory D. Ahrens
  • Email
  • Administrative Assistant
  • Sally A. Salazar
  • Email
Image shows archival Manhattan era bomb photograph

Archival photo, Manhattan Project


To design nuclear weapon primaries and assess their performance, reliability, and surety.

What we do

The Primary Physics and Design Group, XTD-PRI, designs nuclear weapon primaries and assesses their performance and reliability.

XTD-PRI provides intellectual leadership toward improved predictive understanding of primaries, develops primary design and certification methods, and plays a leadership role in the integration of weapons-directed theoretical, experimental and modeling activities throughout the Laboratory.

More broadly, XTD-PRI also applies its technical capabilities to enhance the entire portfolio of work of the X Theoretical Design (XTD) division.