A proton beam from an accelerator incident on target spallates debris. The charged component may be bent away with suitable magnets. The neutral component undeflected by the magnets includes but is not limited to neutrons which may then be directed onto nuclear waste. If the energy range and intensity range of the neutron beam are precisely suitable then radioactive nuclear species in the waste can be transmuted to other non-radioactive species hence eliminating the waste partially if not completely and permanently. This form of sATW requires the infrastructure of a proton accelerator.
Alternatively, neutrons emanating from a fission reactor can be absorbed into a suitably covering blanket around the reactor, spallating further neutrons which similarly can be absorbed by a suitable blanket of waste, effecting a transmutation of the waste. This form of sATW requires the infrastructure of a nuclear fission reactor.
By their natural lack of electric charge, the neutrons cannot be focused or steered by electromagnets as familiarly deployed for electrically charged particle beams. My postdoctoral research includes a nuclear physics method to collimate the neutron beam. This method was originally invented and demonstrated for other purposes; its application in ATW is new and hence unevaluated. It should be applicable to the proton accelerator version of sATW (but not as easily to the fission reactor variety).
Summary of the 1997 IAEA Report on sATW listing sATW efforts in Europe, Russia, Japan and USA is forthcoming
A 2003 IAEA update for sATW is also available
Summary of the 1999 US DOE Report on sATW is forthcoming. This report concludes (p21 of 108) with the following budget (1999 US$millions) for expected efforts towards sATW:
|Program Year||1 & 2||3||4||5||6||Total|
|Separations and Waste Forms||5.4||8.2||12.6||15.3||14.0||55.5|
|Target & Blanket||10.8||12.8||36.4||37.0||26.5||123.5|
A 1999 Argonne National Laboratory Report on sATW is also available
An alternative source of neutrons are nuclear fusion tokamak reactors for tATW
An alternative source of neutrons are muon catalyzed fusion reactors for mATW. My postdoctoral research into the method which results in neutron collimation was discovered in the context of muon catalyzed fusion but only later gave rise to the notion of its advantages for ATW. This gives rise to mATW but the method would also be applicable to the proton accelerator version of sATW but probably not tATW.