2019-09-02 Bloomberg Businessweek

91

Pa

Protactinium

(MOSTLY)

USELESS

BySamanthSubramanian

77

Nuclearpower’sonce-brightpromise

ofreliablecarbon-freeelectricityhas

dimmedthepastthreedecadesbecause

ofescalatingcosts,problemswith

newtechnologies,andthedisastersat

ChernobylandFukushima.Butit’sstill

prettybrightin China.TheInternational

EnergyAgencyexpectsitsnuclear

capacitytogrowby 111 gigawatts

from 2017 to2040,andtherestofthe

world’stodropby7GW.

Anobviousquestion,at leastfor

anyonewho’sseenHBO’sminiseries

Chernobyl, is whethertheseambitions

riska repeatofthecrisesofthepast.

Chinahasn’thadanyseriousnuclear

incidentssinceitsfirstplantbeganoper-

atingin 1991,andtheWorldNuclear

Associationpraisesit for“unprece-

dentedeagernesstoachievetheworld’s

beststandardsin nuclearsafety.”But

a reportpublishedlastyearbyMark

Hibbs,a seniorfellowin theCarnegie

EndowmentforInternationalPeace’s

NuclearPolicyProgram,pointstosev-

eralpotentialchallenges.If Chinabuilds

toomanytypesofreactors—it’sdevel-

opingthreeandexperimentingwith

others,includingthorium-fueledones—

regulatorscouldfindit hardtoset

standardsandconductinspections.The

countryalsofavorspartsfroma domes-

ticmanufacturingindustryfocusedon

92

U

Uranium

Bloomberg Businessweek / SEPTEMBER 2, 2019 THE ELEMENTS

◼ Actinium Priceon request

◼ Thorium $72 / kg Thorium compounds, Indiamarket

◼ Protactinium Not available

◼ Uranium $85.54 /kg Average purchase price, U.S. civilian nuclear power reactors

90

Th

Thorium

URANIUM’S NICER SISTER

By Stephen Stapczynski

THE PROBLEM

Nuclear reactors relying on uranium

are prone to major accidents,

produce waste that’s hard to dispose

of safely, and can make fissile

material for weapons.

THE SOLUTION?

Thorium is more abundant, less

radioactive, produces less waste,

andcan’tbeturnedintonukes.

Theleadingproposedtechnology

forthoriumpower,themolten-salt

reactor,alsooperatesundernormal

atmosphericpressure. So, unlike

reactors that use water to moderate

nuclear reactions inside containment

vessels, thtere’s no chance of

pressure building to the point of

explosion if a problem occurs. The

technology was demonstrated in

U.S. labs in the 1960s, and China

and France are working on it again,

according to the World Nuclear

Association.

THECATCH

Designingreactors, a challenge to

begin with, is that much harder with

an unproven fuel.

▶WHAT’SIT LOOKLIKE?

In daylight,it’ssilverywith

a leadlikesoftness;in the

dark,it’ssurroundedbya

paleblueglow.

▶WHY’SIT

(MOSTLY)USELESS?

It’sfrighteninglyradio-

active,hencetheglow.

▶WHAT’SIT USEDFOR?

Xofigo,a BayerAGdrug

thattreatsprostate

cancer,hasanactive

ingredientderivedfrom

anactiniumisotope.

89

Ac

Actinium

(MOSTLY)

USELESS

BySamanthSubramanian

▶WHAT’SIT LOOKLIKE?

In theairit’sbright

andsilveryfora while

beforea darkfilmof

oxidegraduallycreeps

overitssurface.

▶WHY’SIT

(MOSTLY)USELESS?

Protactinium’slongest-

lastingisotopeis quite

stable,witha half-lifeof

about32,700years, but

it’s scarce. In uranium

ores, it occurs with

a frequency of three

China  Fission

By Dan Murtaugh and

Stephen Stapczynski

NUCLEARPOWERPLANTSIN CHINA

● Operable● Under construction● Planned/proposed

Scientists have filed pat-

ents to fight cancers with^

actinium radionuclides, but

these aren’t close to full-

fledged treatments yet.

▶ CAN I GET SOME?

With difficulty. The most

stableisotope,Ac-227,

hasa half-lifeofabout

21 years, but it’s van-

ishingly rare—a ton of

uranium ore contains just

a tenth of a milligram.

Most of the world’s sup-

ply of Ac-227 is produced

for research purposes by

the Oak Ridge National

Laboratory in Tennessee;

glass vials of the stuff

are available for purchase

by special order. Oak

Ridge provides prices on

request.

partspermillion,at

most.Theworld’sstock

longconsistedmainly

of 125 gramstheU.K.

extractedfrom 60 tonsof

spenturaniumfuelin 1961.

Protactiniumis nowalso

derivedasa byproductof

thoriumfissionreactors.

▶WHAT’SIT USEDFOR?

Practicallynothing.

Geologistscancompare

theconcentrationsof

protactiniumandthoriumto

datemarinesediment

samples,thoughthemethod

worksonlyforsamplesless

than175,000years old.

▶ CAN I GET SOME?

No. Oak Ridge National

Laboratory’s sizable catalog

of radioactive elements

doesn’t even include

protactinium.

lowcosts,a riskwhena typicalplant

needs3,000nuclear-gradevalves,

250 pumps, 44 milesofpiping, 300 miles

ofelectricalwiring,and90,000electrical

components.“Thereis a realpossibility

thatthisissuemayleadtoanaccidentif

notrigorouslypursued,”Hibbswrites.

BeforeFukushima,someestimated

that China’s capacity would reach as

high as 500 gigawatts, almost five

times the current projection. But

withina weekofa tsunamistrikingthe

Japanesenuclearplant,theChinese

governmentsuspendedapprovalsof

newnuclearpowerprojects.It later

loweredplant-buildingtargets,boosted

regulation, and specified that reactor

modelsmustfeaturenewertechnol-

ogytobeapproved.It againpaused

approvals in late 2016,thoughthere

have been reports thedroughtwillend

this year. �With FeifeiShen