1 / 11

Final Meeting

Final Meeting. TW5-TSW-001 Deliverable 2. Culham, October 23–24, 2006. SCK•CEN, L. Ooms. PPCS Model AB. Model AB: Activation analysis R. Pampin UKAEA/ TW4-TRP-002 D2e, April 2005. Dose rate Sv/h. Replacement Schedule. Model AB: Activation analysis

urian
Télécharger la présentation

Final Meeting

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Final Meeting TW5-TSW-001 Deliverable 2 Culham, October 23–24, 2006 SCK•CEN, L. Ooms

  2. PPCS Model AB

  3. Model AB: Activation analysis R. Pampin UKAEA/ TW4-TRP-002 D2e, April 2005 Dose rate Sv/h Replacement Schedule

  4. Model AB: Activation analysis R. Pampin UKAEA/ TW4-TRP-002 D2e, April 2005 Dose rate Sv/h Replacement Schedule

  5. Time Scale • Stage 1: Temporary storage over a time period of maximum 5 years. The storage will be performed in the fusion plant and its major goal is to reduce the dose rate with 1 order of magnitude. • Stage 2: Interim storage over a period of 100 years. The major goal for this on site storage is to reduce the dose rate (a few orders of magnitude) in order to perform off-site transportation. • Stage 3: Final disposal (off site). • Reference: A. Natalizio (ENSEC); In-vessel component storage, EFDA Task TW2-TRP-PPCS17 – Deliverable 4, dd. 10-01-2003 • Storage after irradiation • Recycling of components • separation • recycling of materials • refabrication and testing • Storage awaiting reuse • Reuse • Separation & recycling of materials (1 year). • Refabrication & testing (1 to 2 years) Replacement scheme

  6. Simulation of limits for HOR Limits defined in the past: 1000 Gq/g => 4 µSv/h => 6,4 mSv/y10 µSv/h => 16 mSv/y (full exposure = 1600 h) • Limits are very conservative (they meet the ICRP norm for the operators) • The goal must not be to increase the limits (ALARA) • A simulation with a reduced exposure confirms that materials must not be classified immediately in remote handling recycling if one applies: • Shielding • Reduced exposure • Other measures to reduce the exposure of the operators First conclusion: • The limit for Hands On Recycling has to be kept at 10 µSv/h • Materials with a dose rate above 10µSv/h must not directly be classified as remote recycling

  7. Simulation of limits for HOR Other remarks: • Using dose rates for limits between categories starting from HOR is much more logical than using specific activities. • On the contrary clearance based on 1 µSv/h has no sense, since pure beta-emitting isotopes can still exceed clearance limits. Therefore the principle of clearance index should be applied for those materials • Confinement of the workspace is inevitable, due to the Tokamak dust, Tritium…)

  8. Remote Handling Facilities • Dose rates of fusion components are acceptable for existing facilities • The 5 years of temporary storage will reduce the dose rates of the components. • But! What about build up after a second irradiation cycle • The needed services are very specialised (testing and fabrication), precision ± 10 µm, • Up to now only simple products were fabricated (melting) • Confinement is unavoidable to protect the operators from internal contamination

  9. Fusion classification

  10. SRM is subdivided into two groups • Hands on recycling (dose rate up to 10 µSv/h) • Shielded recycling (dose rate between 10 µSv/h and 2 mSv/h) • CRM + PDW becomes one group Remote Recycling (above 2 mSv/h) • NAW (Clearance) is not defined by the dose rate of the materials but by the Clearance index. New proposal for Classification Ic < 1 Clearance

  11. Report: Precondition of the dose rate limits for recycling TW5-TSW-001 D2 SCK•CEN: R-4377, 276-06-06, L. Ooms, S. Boden, S. Leblanc Draft available, final report after today’s discussion

More Related