Making Special Materials Inside Commercial Nuclear Power Plants

This patent describes a method for using the neutron radiation inside large commercial nuclear power reactors, specifically in their existing instrumentation tubes, to create useful isotopes like those used in medicine or industry.

What it covers

This patent outlines a method for producing isotopes in a "light water commercial power reactor" that generates at least "100 mega-watts thermal" power (Claim 1). The process involves placing a "non-fissile" material, called an "irradiation target," into an "instrumentation tube" within the reactor (Claim 1). This target is then exposed to the "neutron flux" generated by the reactor, causing it to transform into a desired isotope (Claim 1). The placement of the target is carefully chosen based on factors like the half-life of the desired isotope and the neutron absorption rate (Claim 1). For example, a cobalt target could be inserted to produce Cobalt-60, a radioisotope used for medical sterilization.

What it doesn't cover

• —Does not cover producing isotopes using materials that are fissile, meaning they can split and release energy, as the target must be "non-fissile" (Claim 1).
• —Does not cover isotope production in reactors that are not "light water commercial power reactors" or those generating less than "100 mega-watts thermal" (Claim 1).
• —Does not cover placing irradiation targets directly within the reactor's fuel bundles; it specifically uses an "instrumentation tube" (Claim 1).
• —Does not cover methods where the containment structure holding the target significantly changes its nuclear properties during the irradiation process (Claim 4).
• —Does not cover producing isotopes in dedicated research reactors, as it specifies a "commercial power reactor" for electrical power production.
• —Does not cover methods where the target is not positioned based on factors like half-life, irradiation duration, or neutron absorption rate (Claim 1).

The clever bit

The clever aspect is using the existing "instrumentation tube" of a commercial power reactor, typically meant for monitoring, as an accessible and convenient location to irradiate "non-fissile" targets. This avoids complex and costly modifications to the reactor's core or fuel bundles.

Why it matters

Many critical isotopes, especially radioisotopes used for medical imaging and treatment, are currently produced in a limited number of dedicated research reactors. This patent offers a way to leverage existing commercial power reactors, which are more common, for isotope production. This could help diversify the global supply chain for important isotopes, potentially making them more accessible and affordable for healthcare and industrial applications.

Real-world examples

• 1.Production of Cobalt-60 for sterilizing medical equipment and treating cancer.
• 2.Production of Iridium-192 for industrial radiography to inspect materials.
• 3.Production of Thulium-170 for portable gamma sources in medical applications.
• 4.Production of stable isotopes for various industrial and research uses.