Editing Pebble bed modular reactor (section)

== Reactor design ==
The PBMR is characterised by inherent safety features, which mean that no human error or equipment failure can cause an accident that would harm the public.<ref name=nei-20090401a>{{cite news|url=http://www.neimagazine.com/story.asp?storyCode=2052590|title=PBMR: hot or not?|author=Steve Thomas|publisher=Nuclear Engineering International|date=1 April 2009|archiveurl=https://web.archive.org/web/20110613104516/http://www.neimagazine.com/story.asp?storyCode=2052590|archivedate=13 June 2011}}</ref>

Heat from the PBMR can be used for a variety of industrial process applications, including process steam for cogeneration applications, in-situ [[oil sands]] recovery, ethanol applications, refinery and petrochemical applications.<ref name=pbmrweb-tech>{{cite web |url=http://www.pbmr.co.za/index.asp?Content=226 |title=process heat applications |publisher=PBMR Ltd |archiveurl=https://web.archive.org/web/20120216031414/http://www.pbmr.co.za/index.asp?Content=226 |archivedate=16 February 2012}}</ref> The high temperature heat can also be used to reform methane to produce [[syngas]] (where the syngas can be used as feedstock to produce hydrogen, ammonia and methanol); and to produce hydrogen and oxygen by decomposing water thermochemically.

The PBMR is ''modular'' in that only small to mid-sized units will be designed. Larger power stations will be built by combining many of these modules. As of 2008, 400MWt was emerging as an optimum module size, considerably larger than the original concept size.{{Citation needed|date=February 2009}}

The PBMR is fuelled and [[neutron moderator|moderated]] by graphite fuel spheres each containing [[TRISO]] coated low enriched uranium oxide fuel particles. There are 15000 fuel particles per fuel sphere the size of a [[billiard ball]]. "Each fuel pebble contains 9 g of uranium, and this holds enough generation capacity to sustain a family of four, for a year. Five tons of coal and up to 23 000 m<sup>3</sup> of water will be required to generate one pebble's energy".<ref name=en-20070810a>{{cite news|url=http://www.engineeringnews.co.za/article/fuel-for-thought-pbmr-fuel-set-for-yearend-production-2007-08-10|title=Fuel for thought – PBMR fuel set for year-end production|author=Esmarie Swanepoel|publisher=Engineering News|date=10 August 2007|accessdate= 2009-05-15 |archive-url= https://web.archive.org/web/20120219082021/http://www.engineeringnews.co.za/article/fuel-for-thought-pbmr-fuel-set-for-yearend-production-2007-08-10 |archive-date= 2012-02-19}}</ref>

The concept is based on the [[AVR reactor]] and [[THTR]] in Germany, but modified to drive a [[Brayton cycle|Brayton]] [[closed-cycle gas turbine]].<ref>[http://iaea.org/OurWork/ST/NE/inisnkm/nkm/aws/htgr/abstracts/abst_gtpcs_8.html IAEA Technical Committee Meeting on “Gas Turbine Power Conversion Systems for Modular HTGRs”]{{Dead link|date=May 2019 |bot=InternetArchiveBot |fix-attempted=yes }}, held from 14–16 November 2000 in Palo Alto, California. [[International Atomic Energy Agency]], Vienna (Austria). Technical Working Group on Gas-Cooled Reactors. [http://iaea.org/OurWork/ST/NE/inisnkm/nkm/aws/htgr/fulltext/gtpcs_8.pdf IAEA-TECDOC—1238, pp:102–113]{{Dead link|date=May 2019 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> The core design is annular with a centre column as a [[neutron reflector]].<ref name="en-20070810a"/>