## Facts

- Glenn T. Seaborg filed a patent application claiming (1) “Element 95” (americium) and (2) “the isotope of element 95 having the mass number 241” (americium-241).
- The application disclosed americium isotopes (americium-241 and americium-242) and methods to produce and purify americium, including production in a high-power nuclear reactor operated for an extended period.
- The Patent Office rejected the composition claims as anticipated by a prior reactor patent (the Fermi reactor patent), reasoning that americium would necessarily be produced during reactor operation.
- The prior reactor patent did not mention americium or element 95, but described an operating example (e.g., prolonged high-power operation followed by shutdown and unloading) directed to producing and separating plutonium.
- The parties agreed that americium-241 would, as a matter of nuclear physics, be formed during the described reactor operation; however, the maximum amount calculable from the operating example was about 6.15 × 10^-9 gram, dispersed throughout approximately forty tons of intensely radioactive material.
- The Board of Appeals affirmed the rejection on an “inherency” theory, and Seaborg appealed to the Court of Customs and Patent Appeals.

## Issues

1. Whether claims to a new element (americium) and a specific isotope (americium-241) are anticipated by a prior patent that neither identifies the element nor teaches its isolation, solely because the prior process would inevitably create undetectably small amounts of it.

## Decision

- The court reversed the Board of Appeals.
- The court held that the reactor patent did not anticipate the claims to element 95 or americium-241.
- The mere inevitable formation of an unknown, undetectable trace amount of a substance in a prior-art process, without recognition or an enabling teaching to identify and recover it, did not constitute an anticipating disclosure placing the claimed subject matter in public possession.

## Legal Principles

- Anticipation requires a prior-art disclosure that makes the claimed subject matter available to the public in an enabling way; theoretical or hindsight recognition that a process must have produced a trace by-product is insufficient.
- “Inherency” does not establish anticipation where the allegedly inherent product is produced only in minute, practically unrecoverable quantities and the reference provides no teaching that would allow a skilled person to identify and obtain it.
- A prior reference directed to producing other materials does not anticipate a newly claimed chemical species when it neither describes that species nor supplies information enabling its separation, identification, and use.

## Conclusion

The court held that americium and americium-241 were not anticipated by a reactor patent that, at most, would have produced only undetectable trace amounts of americium without recognition or an enabling disclosure, and it therefore reversed the Patent Office’s rejection of Seaborg’s composition claims.


In re Seaborg, 328 F.2d 996 (C.C.P.A. 1964)