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Challenges in the radwaste management and recycling of beryllium (UT-BER-2005)

Challenges in the radwaste management and recycling of beryllium (UT-BER-2005). Frank Druyts. Introduction. Considering surface disposal of fusion beryllium waste, we concluded in the past that There is a need for fusion-specific waste acceptance criteria.

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Challenges in the radwaste management and recycling of beryllium (UT-BER-2005)

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  1. Challenges in the radwaste management and recycling of beryllium (UT-BER-2005) Frank Druyts

  2. Introduction • Considering surface disposal of fusion beryllium waste, we concluded in the past that • There is a need for fusion-specific waste acceptance criteria. • Tritium, chemical toxicity and transuranics (due to U traces) might pose a problem. • Therefore, we applied performance assessment methods to investigate the tritium and chemotoxicity problem and assessed the extent of the ‘uranium problem’.

  3. Tritium is not a problem for surface disposal, but the chemotoxicity is! • A Safety Assessment Modelling approach by Dirk Mallants showed that: • tritium releases to the biosphere are well below the dose limit for the public (1 mSv/y) if the disposal design and practice are optimised for fusion waste. • The chemotoxical impact in the case of an intrusion scenario is unacceptable, even if the repository design is optimised. • Deep geological disposal seems acceptable, from a safety assessment point-of view, but is undesirable on the basis of public acceptance

  4. Recycling is the preferred option for fusion beryllium waste, with two showstoppers • Any process for the recycling of beryllium pebbles or tiles will have to deal with • The high amount of tritium produced through neutron irradiation of the beryllium and its fast release at ~800°C. • The presence of transuranics due to traces of uranium in present grades of beryllium. • At the end of 2005, we specifically focused on the uranium problem • Discussions at the 7th International Workshop for Beryllium Technology (Santa Barbara, 30 Nov – 2 Dec)

  5. The uranium problem is already apparent in MTR beryllium waste • USA case study: • Be waste from the Idaho ATR is classified as TRU waste • A paraffine-based grout is injected into the soil where Be is burried to immobilise RN associated to the beryllium waste • In partical Pu and Am pose a problem • 99% of the transuranics should be removed

  6. The bad news: Be grades contain U levels up to 18 ppm (and higher…) • Kupriyanov (RF) studied 35 beryllium grades and found U concentrations between 0,05 and 18 ppm • Alves (ITN Lisbon) measured up to 200 ppm U in the Japanese titanium beryllides

  7. But there is also good news • U-containing beryllium can be purified: • Vacuum distillation • Nitric acid • Polyethylene glycol • Chlorination • Zone melting • … • Brush-Wellmann: ‘essentially U-free beryllium will be available’ • Up to 5 years ago, the U was not an issue, except in BeCu alloys (esthetical problem) • There are U-free Be-ores (USA, Kazachstan) B-W has access to. • Cost of U-free Be would be comparible to current grades. • Volume of U-free reserves??

  8. Conclusions • The presence of U traces is a problem to be taken into consideration. • ‘Acceptance criteria’ (U levels) for Be used in ITER (and further on) should be developed (cfr. Russian and Chinese beryllium grades) in a dialogue with the industry.

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