Design improvements and lessons learned for the TFTR Tritium Cleanup and Gas Holding Tank Sampling systems

Kalish, M.; LaMarche, P. H.; Viola, M.; Anderson, James L.; Ciebiera, L.; Rossmassler, R.; Walters, R.T.; Langish, S.; Casey, M.

doi:10.1109/fusion.1995.534283

Cited by 6 publications

(2 citation statements)

References 2 publications

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“…The molecular sieve beds absorb the water vapor out of the effluent stream which is then stacked. In the holding tanks the tritium content is measured with an ion chamber and PVT measurements 2 . For direct processing of the vacuum vessel at near atmospheric pressure this arrangement was modified.…”

Section: Torus Cleanup Systemmentioning

confidence: 99%

10.2172/620651

Blanchard¹,

Camp²,

Carnevale³

2000

CrossRef Listing of Deleted DOIs

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In the summer/fall of 1996 after nearly three years of D-T operations, TFTR underwent an extended outage during which large port covers were removed from the vacuum vessel in order to complete upgrades to the tokamak. Following the venting of the torus, a three tier system was developed for the outage in order to reduce and control the free tritium in the vacuum vessel so as to minimize the exposure to personnel during port cover removal and reinstallation. The first phase of the program to reduce the free tritium consisted of direct flowthrough of room air through the vacuum vessel to the molecular sieve beds using the Torus Cleanup System. Real time measurements of the effluent tritium concentration were used to derive the amount of tritium removed from the torus. Once the free tritium in the vessel had been reduced to approximately 50 Ci, a second phase was initiated using a 55 Gallon Drum Bubbler System for the direct processing of the vacuum vessel to further lower the tritium level in the torus. Tritium oxide is absorbed by the bubbler system with the exhaust vented to one of the tritium monitored HVAC ventilation stacks. To preclude the release of tritium to the Test Cell location of TFTR and to minimize the exposure of workers, a variable flow exhaust system was employed in order to maintain a negative pressure in the vacuum vessel between 0.05" and 1.5" w.c. during the removal of port covers ranging in size from approximately 5 to 1000 in 2. These systems were completely successful in reducing and controlling the free tritium in TFTR and were instrumental in maintaining ALARA (As Low As Reasonably Achievable) exposures to tritium during the 1996 outage. These systems are again being utilized during the safe shutdown and decommissioning of TFTR which commenced in April of 1997. This paper describes in detail the configuration of these systems and the data obtained during the outage and safe shutdown of TFTR.

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Section: Torus Cleanup Systemmentioning

confidence: 99%

10.2172/620651

Blanchard¹,

Camp²,

Carnevale³

2000

CrossRef Listing of Deleted DOIs

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“…No degradation of the oxidation performance of hydrogen and methane was observed under the co-existence of CO or CO 2 even up to 10-20% in air [13]. Although limited studies have been reported for the performance of ADS with the existence of SF 6 gas [14,15], the data are scarce. Tritiated water is produced in the regeneration process of ADS and is subsequently processed by the ITER water detritiation system (WDS).…”

Section: Introductionmentioning

confidence: 99%

Studies on the behaviour of tritium in components and structure materials of tritium confinement and detritiation systems of ITER

Kobayashi¹,

Isobe²,

Iwai³

et al. 2007

Nucl. Fusion

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Confinement and the removal of tritium are key subjects for the safety of ITER. The ITER buildings are confinement barriers of tritium. In a hot cell, tritium is often released as vapour and is in contact with the inner walls. The inner walls of the ITER tritium plant building will also be exposed to tritium in an accident. The tritium released in the buildings is removed by the atmosphere detritiation systems (ADS), where the tritium is oxidized by catalysts and is removed as water. A special gas of SF6 is used in ITER and is expected to be released in an accident such as a fire. Although the SF6 gas has potential as a catalyst poison, the performance of ADS with the existence of SF6 has not been confirmed as yet. Tritiated water is produced in the regeneration process of ADS and is subsequently processed by the ITER water detritiation system (WDS). One of the key components of the WDS is an electrolysis cell. To overcome the issues in a global tritium confinement, a series of experimental studies have been carried out as an ITER R&D task: (1) tritium behaviour in concrete; (2) the effect of SF6 on the performance of ADS and (3) tritium durability of the electrolysis cell of the ITER-WDS. (1) The tritiated water vapour penetrated up to 50 mm into the concrete from the surface in six months' exposure. The penetration rate of tritium in the concrete was thus appreciably first, the isotope exchange capacity of the cement paste plays an important role in tritium trapping and penetration into concrete materials when concrete is exposed to tritiated water vapour. It is required to evaluate the effect of coating on the penetration rate quantitatively from the actual tritium tests. (2) SF6 gas decreased the detritiation factor of ADS. Since the effect of SF6 depends closely on its concentration, the amount of SF6 released into the tritium handling area in an accident should be reduced by some ideas of arrangement of components in the buildings. (3) It was expected that the electrolysis cell of the ITER-WDS could endure 3 years' operation under the ITER design conditions. Measuring the concentration of the fluorine ions could be a promising technique for monitoring the damage to the electrolysis cell.

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