Submarine Reactor Monitoring with Anti-Neutrinos

Compact, modular reactors have been employed in UK submarines since the 1960's. Originally these reactors, designed and built by Rolls-Royce, were refuelled 2-4 times throughout the lifetime of the boat, however, due to the costs involved and safety implications, UK doctrine changed circa 2000 to a fuelled-for-life approach. To date the performance of UK naval reactors has been justified against instrumented prototypes running at the Naval Reactor Test Establishment (NTRE) in Dounreay. This
establishment is planned to cease operation in the very near future and hence the successor-class submarine will have no prototype. Intended to replace existing Vanguard-class platforms, and planned to enter service circa 2030, successor will have a new reactor design that will be
justified against high-fidelity computer modelling. Without a method of assessing reactor core performance in-situ and through-life, this presents a significant operational risk. As the only radiation carrying information indicative of core burn up that is capable of passing
through the thick reactor shielding, anti-neutrinos have been identified as a potential solution for through-life monitoring. It is proposed that before construction of successor-class submarines commences early in the next decade, the technology and methodology for reactor-core monitoring
via anti-neutrino flux measurements be proven such that it can be incorporated into the successor-class design. Given there are limited opportunities to trial such technologies, it is proposed that
opportunities be taken to do this during reactor power range testing of Astute-class submarines in-build at the BAE facility in Barrow-in-Furness.