# Tritium in [15O]water, its identification and removal.
> [15O]水中のトリチウムの同定と除去法の開発


## Abstract

This study investigated the identity and chemical form of a long-lived radionuclide found in [15O]water synthesized via the 14N(d,n)15O nuclear reaction, and developed a method for its removal to aid radioactive waste management. The contaminant was identified as tritium through comparison of its physical half-life and beta-ray energy spectrum with known tritium characteristics. Within the irradiated target gas, the predominant chemical form of tritium was determined to be molecular hydrogen (H2). Complete removal of tritium radioactivity was achieved by routing the target gas through a heated palladium catalyst followed by a calcium chloride column prior to final [15O]water synthesis, with no substantial reduction in product yield. This approach offers a practical solution for tritium elimination in [15O]water production.

### Mechanism

A heated palladium catalyst oxidizes tritium present as molecular hydrogen in the target gas; subsequent passage through a calcium chloride column achieves complete removal before [15O]water synthesis.

## Bibliographic

- **Authors**: Sasaki T, Ishii S, Tomiyoshi K, Ido T, Miyauchi J, Senda M
- **Journal**: Appl Radiat Isot
- **Year**: 2000
- **PMID**: [10697723](https://pubmed.ncbi.nlm.nih.gov/10697723/)
- **DOI**: [10.1016/s0969-8043(99)00134-7](https://doi.org/10.1016/s0969-8043(99)00134-7)
- **Study type**: other
- **Delivery route**: not specified
- **Effect reported**: not assessed

## Delivery context

The delivery route is not clearly identifiable from this paper. For hydrogen intake, inhalation is the most efficient route; inhalation, however, carries explosion risk (empirical LFL of 10%; high-concentration devices are not recommended).

## Safety notes

The delivery route is not clearly identifiable from this paper. For hydrogen intake, inhalation is the most efficient route; inhalation, however, carries explosion risk (empirical LFL of 10%; high-concentration devices are not recommended).

See also:
- [Inhalation concentration and LFL / UFL](https://h2-papers.org/en/safety-notes/inhalation-concentration)
- [Consumer Affairs Agency accident cases](https://h2-papers.org/en/safety-notes/accident-cases)

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> **Cite as**: H2 Papers — PMID 10697723. https://h2-papers.org/en/papers/10697723
> **Source**: PubMed PMID [10697723](https://pubmed.ncbi.nlm.nih.gov/10697723/)