The Economist - UK (2022-03-26)

The Economist March 26th 2022 Science&technology 79

brings  safety  benefits,  too.  Even  if  the  in­
ternal cooling were to fail, the external wa­
ter in the pond has enough capacity to ab­
sorb the diminutive reactor’s heat produc­
tion.  Besides  its  putative  plant  in  Idaho,
NuScale  has  seen  expressions  of  interest
from Kazakhstan, Poland and Romania.
Other  smrs  stretch  the  definition  of
“small”. Rolls­Royce’s are designed to pro­
duce  470mw of  electricity—more  than
most  of  the  first­generation  Magnox  nuc­
lear power stations Britain began building
in the 1950s. That requires the sorts of ac­
tive safety systems found in ordinary nuc­
lear power stations, such as coolant pumps
and backup generators to ensure constant
running  if  something  goes  wrong.  This
adds complexity, and therefore cost. 
But  most  analysts  reckon  bigger  size
means economies of scale, and thus cheap­
er  power.  “The  reason  we’re  at  470mwis
that’s the most power we can get out of our
footprint, while keeping every component
fitting  on  a  lorry,”  says  Alastair  Evans,  a
spokesman  for  Rolls­Royce.  The  firm
hopes that, when and if its production line
is up and running, each of its jumbo smrs
should  cost  £1.8bn  ($2.4bn)  and  take
around four years to build. It has seen in­
terest  from  America,  the  Czech  Republic
and Turkey.
NuScale, Rolls­Royce and the China Na­
tional  Nuclear  Corporation,  which  is
building  the  plant  in  Hainan,  are  sticking
with tried­and­true designs. All their pro­
posed  plants  are  light­water  reactors
(lwrs),  which  use  ordinary  water  both  to
cool the core and to moderate the speed of
the  nuclear  chain­reaction.  Since  most  of
the world’s existing reactors are also lwrs,
they  hope  sticking  with  the  same  general
design will speed up regulatory approvals.
(NuScale’s design was approved by Ameri­
ca’s  Nuclear  Regulatory  Commission  in
2020, four years after it was submitted.)
Other  designs  are  more  exotic,  relying
on molten lead or sodium, or gaseous heli­
um, instead of water, to cool their cores. x­
Energy  and  u­Battery,  American  and  Brit­
ish firms respectively, are betting on min­
iature helium­cooled reactors. These oper­
ate  at  much  higher  temperatures  than
lwrs.  The  helium  in  u­Battery’s  reactor
will  reach  temperatures  of  about  750°C,
says Tim Abram, the firm’s chief engineer. 
This  means  that,  besides  electricity,
such reactors could also sell heat. Many in­
dustrial  processes  run  at  high  tempera­
tures.  At  the  moment,  that  comes  mostly
from burning fossil fuels. u­Battery hopes
its  reactors  might  one  day  find  a  home  in
industries  ranging  from  glass  and  ceram­
ics to steel, cement and paper. They could
even,  says  Mr  Abram,  be  used  to  produce
hydrogen  for  energy  storage  via  a  process
called  thermochemical  splitting,  which
employs  heat  rather  than  electricity  to
cleave water into oxygen and hydrogen.

Italllooksgoodonpaper.Buthistory

counselsa degreeofscepticism.Previous

attemptstobuildcommercialsmrs,dating

backtothe1960s,havefounderedonthe

twinrocksofeconomicsandtechnology.

Thebiggestdifficulty,saysM.V.Ramana,a

physicistattheSchoolofPublicPolicyand

GlobalAffairsattheUniversityofBritish

Columbia,isthatsmallreactorsstartata

disadvantagetotheirbiggercousins.The

costofbuildinga reactorgrowsmoreslow­

ly thanitspower output,hesays.Other

thingsbeingequal,biggermeanscheaper.

Whether mass production can over­

come that disadvantage remains to be

seen.NuScale’sIdahoplantispaidforin

partbyfederalsubsidy.Butcostshaveris­

en,saysDrRamana,from$3.6bnin 2017 to

$6.1bnin2020.Severalofthefirm’scom­

mercialpartnerspulledoutoftheproject

in2020.Thatisnotencouragingfora tech­

nologywhichmustcompeteforlow­car­

boninvestmentwithsolarandwindener­

gy,thecostsofwhichcontinuetofall.

If atfirstyoudon’tsucceed...

Nuclear power is, however, these days

lookinglessexpensivethanitdid.Onebig

plantunderconstructioninBritain,onthe

coastofSomerset,hadtobepromisedan

inflation­linkedelectricitypricestartingat

£92.50permegawatt­hourin2013.Atthe

time,thisdealwascondemnedastooex­

pensive. But amid gas shortages and a

dearth of wind, British electricity costs

havebeenabovethatlevelformostofthe

pastsixmonths.

The International Energy Agency

pointsoutthatoncetheneedforstorageor

backupgenerationistakenintoaccount

renewablesaremoreexpensivethantheir

stickerpricesuggests.And,asRussia’sin­

vasion of Ukraine shows, energy policy

mustweighfactorsbeyondbean­counting.

Whethersmrs canhelpmakenuclearpow­

erattractiveagainremainstobeseen.But

theiradvocatesareunlikelytogeta better

chancetomaketheircase.n

Pool party

NuScale reactor

Water Steam to drive turbines

feed

Containmentvessel

Coolingcircuitis driven

byconvection

Reactorpressurevessel

Steam-generatortubes

Reactorcore

Source: NuScale

Underground cooling-

water pool

Person

ThewarinUkraine(I)

Dealing with

degradation

D

egrading andideally destroying your

opponents’ ability to communicate are

elementary military tactics. And, in its war

on Ukraine, Russia has certainly attempted

to do this. These days, closing down com­

munications focuses on the enemy’s inter­

net capabilities. So it is not surprising that

analyses  by  NetBlocks,  a  firm  in  London

that  monitors  internet  activity,  suggest

that  the  number  of  devices  connected  to

Ukraine’s  internet  has  fallen  by  nearly  a

quarter  since  Russia’s  onslaught  began.

Alp  Toker,  NetBlocks’  founder,  describes

that  loss  as  striking.  But  it  could  be  a  lot

worse,  for  it  means  that  most  Ukrainians

are still online. What is going on?

For  one  thing,  Ukraine  boasts  an

unusually  large  number  of  internet­ser­

vice  providers—by  one  reckoning  the

country  has  the  world’s  fourth­least­con­

centrated internet market. This means the

network has few choke points, so is hard to

disable. In this, indeed, it fulfils one objec­

tive  of  the  internet’s  ancestor  from  the

1970s, arpanet, which was intended to be

similarly  resilient  to  attack.  Repair  crews,

for their part, are toiling heroically, includ­

ing,  when  possible  and  more  efficient,  by

fixing equipment owned by competitors.

As  for  cyber­attacks,  at  the  invasion’s

outset  hackers  shut  down  a  proportion  of

the satellite links that Viasat, an American

firm,  provides  to  clients  who  include

Ukraine’s  armed  forces.  That  attack  ap­

pears  to  have  been  an  upload  of  malware

disguised as a legitimate software update.

Overall,  however,  cyber­attacks  have  not

been as disruptive as feared. This suggests

that “cyber aid” provided by the West in re­

cent years was money well spent. Josh Los­

pinoso,  who  used  to  help  America’s  army

and National Security Agency (nsa) devel­

op hacking software, says Ukraine’s cyber­

resilience could be a sign that agencies in

natocountries are assisting on the sly.

Beyond  all  that,  Russian  units  seem  to

be  leaving  parts  of  the  network  alone,  at

least  for  now.  These  include  sections  that

are accidentally providing them with data

on  targets,  reckons  Kenneth  Geers,  also

once an official at the nsaand now work­

ing  at  the  nato Co­operative  Cyber  De­

fence  Centre  of  Excellence,  in  Tallinn,  Es­

tonia.  Dr  Geers  says  Russians  are  feeding

information to artillery teams by scanning

social  media  and  studying  intercepted

texts  and  calls,  looking  for  messages  that

reveal military savvy and intent. If they can

Ukraine’s internet is holding up better

than expected to Russian attacks