UK to test new ‘Astraea’ nuclear warheads without detonation

Like the nuclear warheads, the UK has pledged to replace its aging Vanguard class with new Dreadnought-class submarines by the mid-2030s. “UK is committed to replacing our sovereign warhead in parliament in February 2021,” the UK’s MoD shared in a white paper.

The new warheads will be tested non-intrusively using highly specialized equipment. “Using modern and innovative developments in science, engineering, manufacturing, and production at AWE [the Atomic Weapons Establishment], we will ensure the UK maintains an effective deterrent for as long as required,” the MoD explained.

Boomless nuclear warhead testing

“This will be the first UK warhead developed in an era where we no longer test our weapons underground, upholding our voluntary moratorium on nuclear weapon test explosions,” the MoD explained.

The MoD has also explained that the UK’s current stockpile of nuclear warheads will be maintained until Astraea is officially available. Work on Astraea is underway as part of a multi-billion-pound effort to modernize the British nuclear enterprise.

Information on the A21 is scarce, and its expected output is unknown. However, the MoD has disclosed that the Astraeas will be integrated into Mk 7 re-entry vehicles.

These are newly developed designs that will also be used for the upcoming U.S. W93 warhead. The MoD also shared very few technical details about the testing. However, it did give us some insight into what is on the cards, namely a laser called “Orion.”

“We have developed unique and world‑leading technology to validate the UK’s warhead stockpile. The Orion laser helps our physicists and scientists research the physics of those extreme temperatures and pressures in a nuclear explosion to understand better the safety, reliability, and performance of nuclear warheads,” explains the MoD.

Joint venture with France

The laser is being used collaboratively with UK academia and US teams in their national laboratories, as per the UK’s MoD. But that is only part of the story.

“Supercomputing is also a crucial capability, enabling simulations that allow us to develop a safe, assured warhead without detonation. AWE has recently commissioned a supercomputer named ‘Valiant,’ one of the most powerful computers in the UK, to validate our nuclear warhead’s design, performance, and reliability,” the MoD added.

A joint facility in France called EPURE will support the development of the Astraea by British and French authorities. EPURE is a state-of-the-art hydrodynamic facility located in Valduc, France, near Dijon.

The white paper explained that hydrodynamic testing uses radiography to measure the performance of materials at extreme temperature and pressure.

“While the UK and France maintain operational independence, the facility will be jointly managed, with both nations performing sophisticated experiments to inform their modeling of the performance and safety of nuclear weapons without undertaking nuclear explosive tests,” it added.