POWER April 2021 - 7

GLOBAL MONITOR
2. This rendering of the Chalk River MMR
shows the reactor pressure vessel on the left
side of the image, with helium circulator to its
right. According to Ultra Safe Nuclear Corp.'s
website, " The buried reactor core consists of
hexagonal graphite blocks containing stacks
of Ultra Safe's FCM [Fully Ceramic Microencapsulated]
fuel pellets. " Helium gas is the
MMR's primary coolant; the helium passes
through the nuclear core and is heated by the
controlled nuclear fission process. The helium
then transports the heat away from the core
to the molten salt system. Courtesy: Ultra
Safe Nuclear Corp.
other HTGR designs. " Chrobak said the
MMR uses USNC's proprietary Fully
Ceramic Microencapsulated (FCM) fuel,
which enhances the already very high
fission product retention of tristructural
isotropic (TRISO) fuel.
TRISO fuel particles have a layered
shell, which can protect the uranium
inside from melting under even the
most extreme conditions that could occur
in a reactor. The use of TRISO fuel
allows for the design of reactors with
extremely low release of fission products
both during normal operation, and
in the event of failure. FCM fuel coupled
with the intrinsic characteristics of the
MMR reactor design allows for an extremely
simplified design of the plant
while maintaining a robust safety case,
according to Chrobak.
The Chalk River MMR plant is designed
to use an intermediate heat
transfer loop, based on the molten salt
technology developed and deployed in
concentrating solar plants, to transfer
the heat from the reactor to the adjacent
plant. Chrobak said this allows the
reactor to be decoupled from the client
application, and makes the reactor " very
good for both generating electricity and
process heat. "
He said an MMR plant can generate
from 0% to 100% process heat, and 0%
to 100% electrical power with the same
flexibility as a gas boiler or gas turbine.
The MMR, as a small plant, is designed
for mass production and modular construction.
It is factory sealed, delivered,
and retrieved after complete fuel depletion,
resulting in a highly proliferationresistant
design.
Chrobak said the Chalk River project
will serve as a blueprint for future USNC
SMR projects; he said the SMR unit
could produce first power at Chalk River
in late 2024 or early 2025, well ahead of
the scheduled completion date of 2026.
Chrobak noted the reactor's molten salt
loop process also can enable production
of hydrogen. " Right now, the cheapest
way to produce hydrogen is with natural
gas, " Chrobak said, but " the thermochemical
process can produce hydrogen
at a much-higher efficiency, and the
MMR delivers heat at an ideal temperature
for that process. "
SMR technology has received support
from Canadian energy providers including
OPG, Bruce Power, NB Power, and
SaskPower, along with several other
energy companies including Quebec
Hydro, First Nations Power Authority,
and Suncor Energy. Mining companies
such as Rio Tinto and Newmont also are
looking at SMR and MMR technology.
April 2021 | POWER
www.powermag.com
7
https://victoryenergy.com/
POWER April 2021

Table of Contents for the Digital Edition of POWER April 2021
