Global release of tritium into the environment: NPP reactor type contribution

Background

The total pollution of the ecosphere with anthropogenic tritium, which is many times higher than its natural level, is an urgent strategic task.

Aim

To assess the contribution of nuclear power plants (NPPs) to the global tritium release into the ecosphere depending on the type of the NPP reactor.

Materials and methods

We have collected and analyzed more than 6 thousand records on specific and absolute indicators for annual emissions and discharges of tritium entering the environment from NPPs of all reactor types and from other sources worldwide. The statistical analysis of the data was carried out using Microsoft Excel and Statistica software packages.

Results

We have determined the statistical characteristics of specific tritium emissions and discharges for all types of operating reactors. The highest specific emission and discharge is noted for NPPs with PHWR and AGR reactors, respectively; the lowest values are characteristic of RBMK NPPs, including EGP ones. During normal operation of NPPs, discharges cause 61% of the tritium entering the ecosphere. PHWR NPPs make the largest contribution of more than 40 and 99% to global ecosphere discharges and emissions, respectively. As compared to other reactor types, BN breeder reactors insignificantly affect the tritium pollution of the ecosphere.

Conclusion

The accumulated activity of tritium from emissions and discharges during normal operation of the considered NPPs for the period of 1970–2022 is less than 10% of the natural tritium level and less than 2% of the level caused by fission and fusion nuclear weapons tests.