China among the coun­tries look­ing to tho­rium as new nu­clear fuel

China Daily (Canada) - - DEPTH - By KARL WIL­SON

Tho­rium prob­a­bly does not fig­ure high on most peo­ple’s list of en­ergy sources. In fact, many may never have heard of it.

Pro­po­nents of this slightly ra­dioac­tive el­e­ment say it is clean, green and safer than ura­nium.

Tho­rium was be­ing looked at by the United States in the 1950s and 60s. Ac­cord­ing to some ob­servers, how­ever, it was dropped when it was found it could not be weaponized.

To­day, more than a dozen coun­tries, in­clud­ing China, are re­assess­ing tho­rium as an al­ter­na­tive en­ergy source in a world that is de­mand­ing more en­ergy than ever be­fore.

Late last year, it was widely re­ported that China was to spend more than $3 bil­lion on two ex­per­i­men­tal tho­rium molten salt re­ac­tors in the Gobi Desert in the north­west prov­ince of Gansu.

Also last year, NRG, a nu­clear re­search fa­cil­ity in Pet­ten on the Dutch coast, launched the Salt Ir­ra­di­a­tion Ex­per­i­ment Salient in col­lab­o­ra­tion with Com­mis­sion.

In Nor­way, Thor En­ergy has be­gun a four-year study with Ja­pan’s Toshiba-West­ing­house to see whether they can use tho­rium at Nor­way’s con­ven­tional Halden re­ac­tor south of Oslo, the cap­i­tal.

Ja­pan’s In­ter­na­tional In­sti­tute for Ad­vanced Stud­ies is also study­ing molten salt re­ac­tors that use tho­rium.

An­drew Stuch­bery, head of the nu­clear physics de­part­ment at the Aus­tralian Na­tional Univer­sity in Can­berra, said, “Tho­rium has been around for a long time.

“It is also sur­rounded by a lot of myths, such as the US drop­ping its re­search be­cause tho­rium could not be turned into weapons-grade ma­te­rial,” he said.

“In the early days of nu­clear en­ergy, tho­rium was thought to be a lot more abun­dant than ura­nium. The con­cern was that there was not enough ura­nium to sup­port largescale en­ergy pro­duc­tion, so tho­rium was con­sid­ered as a long-term al­ter­na­tive. the Eu­ro­pean

“When the US dropped tho­rium re­search, ura­nium was no longer in short sup­ply and the tho­rium re­search had hit tech­ni­cal ob­sta­cles.”

Ac­cord­ing to Stuch­bery, tho­rium re­ac­tors re­main ex­per­i­men­tal.

“The point is, tho­rium re­ac­tors are still be­ing de­vel­oped and are not com­mer­cially vi­able com­pared to ura­nium re­ac­tors. That is why they have not been widely de­ployed at this stage,” he said.

“They do have ad­van­tages and may be­come im­por­tant in fu­ture. The waste from tho­rium re­ac­tors breaks down faster than the waste from ura­nium re­ac­tors.”

As a me­tal, tho­rium can be found in rocks and soil, and some of the big­gest con­cen­tra­tions are in China, In­dia and Aus­tralia.

It is more abun­dant than ura­nium and is fer­tile rather than fis­sile, mean­ing it can be con­verted into fis­sile ma­te­rial through ra­di­a­tion. It is meant to be used along­side fis­sile ma­te­ri­als such as re­cy­cled plu­to­nium and ura­nium.

Tho­rium trans­forms into fis­sion­able ura­nium-233 when hit by neu­trons. But af­ter use, U-233 cre­ates fewer long-life ra­dioac­tive waste prod­ucts than the con­ven­tional U-235 now used in nu­clear power plants.

The re­ac­tors be­ing built in Gansu will re­port­edly be un­der­ground, next to a salt-rich lake, with the ex­pected 12 megawatts of heat to be linked to a power plant and sev­eral fac­to­ries.

A de­sali­na­tion plant next to the lake will also be con­nected to the re­ac­tors.

The Chi­nese project has been funded by the cen­tral gov­ern­ment, and the re­ac­tors are ex­pected to be op­er­a­tional by 2020, ac­cord­ing to a state­ment on the Chi­nese Academy of Sci­ences’ web­site.

The tech­nol­ogy for the molten salt process is not new.

Oak Ridge Na­tional Lab­o­ra­tory in Ten­nessee, United States, built such a re­ac­tor in the 1960s, but it was shelved by the ad­min­is­tra­tion of pres­i­dent Richard Nixon due to tech­ni­cal prob­lems and be­cause there was no longer an ur­gent need for an al­ter­na­tive to ura­nium.

The tho­rium blue­prints gath­ered dust in ar­chives un­til re­trieved and pub­lished by for­mer NASA en­gi­neer Kirk Sorensen. The US largely ig­nored him; China did not.

Jonathan Cobb, se­nior com­mu­ni­ca­tion man­ager for the World Nu­clear As­so­ci­a­tion, said China is un­der­tak­ing re­search into a broad range of ad­vanced nu­clear gen­er­a­tion tech­nolo­gies, in­clud­ing those that would use tho­rium as a fuel.

He said sev­eral groups are de­vel­op­ing tho­rium-breed­ing molten salt re­ac­tors, oth­er­wise known as liq­uid flu­o­ride tho­rium re­ac­tors.

China is also look­ing to use tho­rium in pres­sur­ized heavy wa­ter re­ac­tors, he said.

The In­ter­na­tional Atomic En­ergy Agency said work on the use of tho­rium as a fuel for nu­clear power be­gan at about the same time that the first stud­ies on ura­nium and plu­to­nium started.

“Tho­rium seemed an at­trac­tive op­tion for nu­clear ma­te­rial,” the IAEA said in a re­port in 2012.

“In spite of a rather long list of ad­van­tages, tho­rium is not yet aug­ment­ing the use of ura­nium fuel on a com­mer­cial ba­sis, although re­search ef­forts re­gard­ing the tho­rium fuel cy­cle con­tinue,” the re­port said.

“As yet, there is no com­mer­cial fab­ri­ca­tion or re­pro­cess­ing in­fra­struc­ture for tho­rium fuel, un­like the avail­able in­fra­struc­ture for the ura­nium fuel cy­cle.

“In the 21st cen­tury, mar­ket con­di­tions may change in such a way that tho­rium op­tions will be­come com­mer­cially more at­trac­tive for nu­clear power ap­pli­ca­tion.”

They (tho­rium re­ac­tors) do have ad­van­tages and may be­come im­por­tant in fu­ture.”

Newspapers in English

Newspapers from China

© PressReader. All rights reserved.