According to records, 97,430 stable iodine tablets were pre-issued to residents of Plymouth, Portland, and Barrow-in-Furness to protect them from radiation from 2016-20121.

Medication was sent to nurseries, schools, nursing homes, and clinics near naval docks. In response to the data procured by Declassified UK, the general secretary of the Campaign for Nuclear Disarmament (CND)  Kate Hudson, stated that the " production, servicing and berthing of nuclear-powered submarines in or near population centers present unacceptable health risks."

Hudson said the submarines, some of which carry nuclear warheads, "need to be disarmed and decommissioned."

BAE Systems, based in Barrow-in-Furness, Cumbria, manufactures nuclear-powered submarines for the Royal Navy.

Should the undersea reactors meltdown contingency preparations are to be in place at all sites

According to Dr. Frank Boulton, a retired NHS physician, “Were a meltdown of a working nuclear-powered engine to occur in the dock, substantial quantities of highly radioactive iodine would be released," adding that those exposed "would be at high risk of developing thyroid cancers as a result of absorbing short-lived isotopes of radio-iodine."

Boulton is a member of global public health charity Medact and explains that the risk is reduced if iodine tablets are taken within a few hours of exposure," although other elements such as air, food, and water, would be contaminated and the iodine would not be effective.

BAE anticipates residents 400 meters downwind of a submarine in Barrow-in-Furness would require iodine in the "first few hours" of a "radiation emergency." 

The armaments firm has enough iodine on hand to treat 32,000 individuals who live or work in a larger four-square-kilometer emergency preparedness zone.

The neighborhood is comprised of closely packed residences and establishments.