Routine Tritium Releases from JET

The JET tritium handling facilities have been designed to minimise tritium releases to the environment and to comply with the ALARP principle. However, it is not practicable to reduce such releases completely to zero and JET has therefore applied for official approval to discharge small amounts of tritium in the form of HTO and HT to the atmosphere and tritiated water to a discharge pipeline. The discharge authorisations are based on estimates of routine operational and maintenance emissions. The basis for these estimates is described and the factors which contribute to uncertainty are discussed. An assessment has been carried out of the resultant radiation doses received by hypothetical critical groups. The methodology is described and it is shown that the total dose, including contributions from direct radiation and releases of activation products, is comfortably within the JET design target and well below UK National Radiological Protection Board limits.