Page 180 - ΝΑΥΤΙΚΑ ΧΡΟΝΙΚΑ - SEPT 2025

Feature

Nuclear-powered ships generate various radioactive power system must handle variable
wastes, including low- and intermediate-level waste power demands for manoeuvring, cargo
(contaminated materials and activated solids), as handling, and port operations. Nuclear
well as spent nuclear fuel, which must be carefully reactors require dedicated mainte-
managed to avoid environmental contamination. nance infrastructure during drydock-
The safe containment and isolation of radioactive ing. Commercial marine reactors aim
waste are crucial to prevent exposure to humans and for long core lives (5-15 years or more),
marine ecosystems. which reduces refuelling frequency
but requires careful lifecycle planning
– refuelling and spent fuel handling
demand strict regulatory compliance
and infrastructure. Operating a nuclear
propulsion system requires trained per-
sonnel knowledgeable in reactor phys-
ics, radiation safety, and emergency
procedures. This is a significant shift
from conventional engine crews. Unlike
naval vessels, commercial nuclear ships
cannot afford to have large crews solely
for nuclear plant management due to
the high cost. Crews must be thoroughly
trained in radiation protection, acci-
dent response, and security protocols
to effectively manage potential nuclear
incidents.

Are there concerns regarding radioac-
tive waste management at sea?
Nuclear-powered ships generate various
radioactive wastes, including low- and
are underdeveloped. Ports to support regulatory frameworks to accommo- intermediate-level waste (contaminated
nuclear vessels must be established. date nuclear-powered vessels. They materials and activated solids), as well
Their creation requires international lack facilities for refuelling, radioactive as spent nuclear fuel, which must be
cooperation. Facilities for reactor main- waste handling, and emergency con- carefully managed to avoid environ-
tenance, waste storage, and emergency tainment. The IMO, in collaboration mental contamination. The safe con-
response are also “sine qua non”. with the IAEA, is working on the Atomic tainment and isolation of radioactive
Technology Licensed for Application at waste are crucial to prevent exposure to
To what extent are flag states and port Sea (ATLAS) project, aiming to establish humans and marine ecosystems. Unlike
authorities prepared to handle international frameworks that will sup- land-based nuclear plants, ships oper-
nuclear-powered ships? port port authorities in regulating and ate in dynamic marine environments,
Licensing nuclear-powered vessels managing nuclear-powered ships and complicating waste handling and stor-
requires close coordination between floating nuclear power plants. age. Refuelling intervals for commercial
maritime and nuclear regulatory author- marine reactors are long (5-15 years), but
ities within flag states. Flag states must How does nuclear propulsion affect ship when refuelling occurs, specialised port
implement safety and security meas- design, maintenance, and crew facilities and protocols are required to
ures applicable to maritime nuclear training requirements? handle spent fuel and radioactive waste
reactors, including accident scenarios, Nuclear reactors require heavy radia- safely. Such infrastructure is currently
piracy threats, and radioactive mate- tion shielding and structural protection limited globally. Potential accidents,
rial safeguarding. Few flag states have against collisions, grounding, and terror- such as collisions or groundings, could
direct experience with nuclear propul- ist attacks. Shielding adds weight and lead to radioactive leaks, posing risks
sion in commercial shipping. Russia volume, which can affect ship stability, of marine pollution and long-term eco-
is an exception, operating nuclear ice- trim, and cargo space. Reactor compart- logical damage. Thermal pollution from
breakers and the floating nuclear power ments must be isolated and secured to reactor cooling systems is also a con-
plant Akademik Lomonosov. prevent unauthorised access. Multiple cern. International regulations govern-
Most commercial ports worldwide containment barriers prevent radioac- ing the shipment, handling, and disposal
lack the specialised infrastructure, tive release during accidents, including of radioactive waste at sea are evolv-
emergency response capabilities, and grounding or capsizing. The reactor and ing but are not yet fully harmonised.

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