Low-Yield, Submarine-Launched Nuclear Warhead: Overview of the Expert Debate [Updated January 5, 2021] [open pdf - 472KB]
From the Document: "The Trump Administration developed a new low-yield version of the W-76 warhead for existing submarine-launched Trident II (D-5) missiles. Unclassified sources state that the existing W76-1 warhead has an explosive yield of around 100 kilotons. The National Nuclear Security Administration (NNSA) has said the low-yield version, the W76-2, would be configured 'for primary-only detonation.' This could mean a yield of less than 10 kilotons. Congress appropriated $65 million for the W76-2 warhead in FY2019 and $10 million to complete work in FY2020. It also authorized $19.6 million in FY2020 for the Navy to integrate the warhead into the submarine force. NNSA completed the first modified warhead in February 2019, began delivering warheads to the Navy by late 2019, and completed the deliveries during FY2020. The Pentagon reported in February 2020 that the Navy had begun deploying the warheads by that time. NNSA did not disclose the total number produced, although it is likely just a very small portion of the W76 stockpile (estimated, in unclassified sources, to be around 1,300 total warheads). The Trump Administration introduced the low-yield version of the W76 warhead in the 2018 Nuclear Posture Review (NPR). It cited the need for additional 'tailored' and 'flexible' capabilities to address the danger of coercive nuclear use, a concept described below, by Russia and North Korea."
CRS In Focus, IF11143
Congressional Research Service: https://crsreports.congress.gov/