The Tritium Laboratory Karlsruhe (TLK)
of the Institute for Nuclear Physics (IKP)
The Handling of Tritium in TLK
The Institute for Technical Physics (ITP) operates the European Tritium Laboratory Karlsruhe (TLK), a semi -technical scale facility for processing tritium, the radioactive hydrogen isotope. With its license to handle up to 40 grams of tritium, its present site inventory of about 25 grams of tritium plus its extensive infrastructure and experimental apparatus TLK is major facility of the German Helmholtz-Gemeinschaft research organisation. The main tasks f TLK are fusion research (ITER) and neutrino physics (KATRIN), plus other EU-projects. TLK is almost unique - only Japan operates a research laboratory with a similar tritium inventory, however with a much smaller laboratory area.
Experimentation with tritium demands an entirely closed tritium processing cycle and a highly developed safety technology. At TLK tritium is always contained within at least two barriers. More than ten glove box systems, total volume of about 125 m³, are operated in an area of 841 m² for experiments and a further area of 615 m² for infrastructure. The glove boxes are constitute the secondary tritium containment for the primary systems of tritium components and pipe work.
For economical but also for ecological imperatives each tritium process is designed to be as efficient as reasonably achievable. Basically the tritium inventory in any experiment should be minimized and all gaseous, liquid and solid waste is detritiated as far as possible. Only when an experimental process has proved theses capabilities does the inventory of tritium at TLK become available for experiments. The simplified diagram shows the self-contained tritium cycle at TLK where tritium is delivered to experiments, recovered and reprocessed for further use.
The tritium at TLK comes from Canada in the form of metal hydride and is essentially a waste product from their natural uranium fuelled, heavy (deuterated) water moderated CANDU reactors. The quantity of tritium delivered to TLK is first confirmed by calorimetric measurements before it is transferred to the Tritium Storage System. It is then prepared for experiments as required in either its pure form, mixed with other hydrogen isotopes or gases or even converted to tritiated water or tritiated methane. After use, the gases are detritiated and the recovered hydrogen isotope mixtures are passed to the Isotope Separation System (ISS) before being returned to the Tritium Storage System.
TLK has a multi-disciplinary team and it encourages intensive co-operation with its European partners, plus American and Japanese scientists and engineers who take advantage of the unique laboratory facilities at TLK in speciifc experimental campaigns.
The TLK has a comprehensive infrastructure, which is focused to support the technical experiments. The infrastructure includes:
- the Tritium Transfer System (TTS), which controls the distribution of tritium to the experiments and other systems
- the Tritium Storage System (TLG), which stores the tritium that is not in actual use in the experiments or other systems
- the Tritium Cleaning System (CAPER) removes impurities from gases containing hydrogen isotopes
- the Tritium Measurement Technique (TMT) analyses the composition of gas samples
- the Isotope Separation System (ISS) can separate protium, deuterium and tritium from each other
- the facility for the regeneration of molecular sieves used to absorb tritiated water vapour (AMOR)
Calorimetry of Tritium in the TLK
The TLK has four different ways for the accounting of tritium. The thermal power of tritium radioactive decay is 0.324 W/g and is used to measure accurately the quantity of a tritium sample. Before a delivery is accepted at TLK the amount of tritium is measured calorimetrically and correlated with the information provided by the supplier, noting the experimental accuracy and radioactive decay in transit. Only after verification is the tritium fed into the transfer system (TTS) and subsequent experiments. The TTS verifies the received amount of tritium with a volumetric measurement and as the case may be another calorimetric determination of the emptied transport vessel. Every transfer of tritium within the TLK requires a measurement and record of the amount of tritium transferred.
|1984||First concept of a Tritium Laboratory|
|1987||First contracts awarded to the industry|
First official approvement of particular sections
|1993||Opening of the Tritium Laboratory Karlsruhe
Approval from the Ministry of the Environment for the use of 10g Tritium
|1995||Tritium experiments with PETRA and CAPRICE
Increase of the tritium quantity to 20g
|1996||Increasing of the working permission to 40g Tritium|
|2001||Decision for the Tritium Laboratory as location for KATRIN
Proposal for the ITER-Brennstoffkreislauf
|2006||Delivery of the main spectrometer|
|2007||New working permission replaces all previous partial permissions
|2010||Delivery of WGTS demonstrator for Cryotest|