Associazione EURATOM ENEA sulla FUSIONE Final Meeting of the Tasks TW5-TSW-001, 001B, October 2006, UKAEA, Culham, UK Final meeting tasks TW5-TSW-001, -001B, -002 D1 & D6 L. Di Pace ENEA CR Frascati October 2006, UKAEA, Culham, UK

Associazione EURATOM ENEA sulla FUSIONE Final Meeting of the Tasks TW5-TSW-001, 001B, October 2006, UKAEA, Culham, UK 2 Outline Aim of the task; Work done for TW5-TSW-001 D1; Work done for TW5-TSW-001-D6; Schedule.

Associazione EURATOM ENEA sulla FUSIONE Final Meeting of the Tasks TW5-TSW-001, 001B, October 2006, UKAEA, Culham, UK 3 Aim of the task Study on Recycling of Fusion Activated Materials; As shown by the PPCS study, all or most of the active materials arising from the operation and decommissioning would be suitable for recycling, after up to 100 years of intermediate storage. Radiological criteria, mostly based on dose rates, have been commonly used to determine if materials would be candidates for recycling. However it is not clear conditions at which recycling, for example in fabrication of components for new fusion power plants, would actually be feasible. Open questions include the availability of suitable processes, the ability to process active material and fabricate new components using RH techniques, and the economic viability of such processes.

Associazione EURATOM ENEA sulla FUSIONE Final Meeting of the Tasks TW5-TSW-001, 001B, October 2006, UKAEA, Culham, UK 4 Deliverable 1 This deliverable will define components and materials involved and determine volumes & masses for PPCS Model AB considering the main boundary conditions. Data from the report UKAEA/TW4-TRP-002 Deliverable 2e Jan 2005 [ TW4-TRP-002D2e_rev1 ] and related neutron transport and activation calculations available on CD. [ TW4-TRP-002D2e_rev1 ]

Associazione EURATOM ENEA sulla FUSIONE Final Meeting of the Tasks TW5-TSW-001, 001B, October 2006, UKAEA, Culham, UK 5 Work done for D1 Input data

Associazione EURATOM ENEA sulla FUSIONE Final Meeting of the Tasks TW5-TSW-001, 001B, October 2006, UKAEA, Culham, UK 6 Work done for D1 Input data Excel file from R. Pampin (UKAEA) clearance levels based on IAEA TECDOC-855 (1996)

Associazione EURATOM ENEA sulla FUSIONE Final Meeting of the Tasks TW5-TSW-001, 001B, October 2006, UKAEA, Culham, UK 7 Work done for D1 Analysis focused on all component materials. Basic criteria used to check recycling/clearance feasibility: –Clearance index (for clearance) [IAEA-TECDOC-855]; –Dose rate < 2 mSv/h (for recycling); –Decay heat < 1 W/m 3 (for recycling); –Specific Activity <1 KBq/g (for recycling) operative value suggested in SCKCEN report [R /05-01 February 2005] (“During the several discussions with experts of the melting facilities, an activity level of 1000 Bq/g should be feasible to handle without remote control, higher values demand remote handling”).

Associazione EURATOM ENEA sulla FUSIONE Final Meeting of the Tasks TW5-TSW-001, 001B, October 2006, UKAEA, Culham, UK 8 Work done for D1 TF coils and VV design similar to ITER; ITER Magnet System ITER Vacuum Vessel

Associazione EURATOM ENEA sulla FUSIONE Final Meeting of the Tasks TW5-TSW-001, 001B, October 2006, UKAEA, Culham, UK 9 Work done for D1 In-vessel modules design for PPCS Model AB

Associazione EURATOM ENEA sulla FUSIONE Final Meeting of the Tasks TW5-TSW-001, 001B, October 2006, UKAEA, Culham, UK 10 Work done for D1 In-vessel modules design for PPCS Model AB FW/SW Cover Stiffening Grid He outlet He inlet Pb-Li inlet Pb-Li outlet BUs Pb-Li distribution box BPs

Associazione EURATOM ENEA sulla FUSIONE Final Meeting of the Tasks TW5-TSW-001, 001B, October 2006, UKAEA, Culham, UK 11 Work done for D1 TF Coils Clearance Index < 1 At shut down 64% of mass is clearable, it increases up to 86% after t  50 y. Mass in kg

Associazione EURATOM ENEA sulla FUSIONE Final Meeting of the Tasks TW5-TSW-001, 001B, October 2006, UKAEA, Culham, UK 12 Work done for D1 TF Coils Decay heat < 1 W/m 3 Mass in kg Contact Dose rate < 2 mSv/h

Associazione EURATOM ENEA sulla FUSIONE Final Meeting of the Tasks TW5-TSW-001, 001B, October 2006, UKAEA, Culham, UK 13 Work done for D1 TF Coils Specific activity < 1 KBq/g After 40 d all TF coil is < 1000 Bq/g, even though the CL is not reached for 14% of the TF coil mass at 100 y. Clearable mass does not change up to t > 10 and < 50 y. At SD, 64% of the TF coil is already clearable. Up to 86% of the TF coil mass is clearable, the remaining 14% is recyclable. Possible limitation from the segmentation of the different strand materials. Mass in kg Remarks on TF Coils

Associazione EURATOM ENEA sulla FUSIONE Final Meeting of the Tasks TW5-TSW-001, 001B, October 2006, UKAEA, Culham, UK 14 Work done for D1 BL First Wall Clearance Index < 1 At t = 100,000 y no clearable mass Mass = 1.97 E+05 kg

Associazione EURATOM ENEA sulla FUSIONE Final Meeting of the Tasks TW5-TSW-001, 001B, October 2006, UKAEA, Culham, UK 15 Work done for D1 Decay heat < 1 W/m 3 Contact Dose rate < 2 mSv/h BL First Wall Mass in kg

Associazione EURATOM ENEA sulla FUSIONE Final Meeting of the Tasks TW5-TSW-001, 001B, October 2006, UKAEA, Culham, UK 16 Work done for D1 BL First Wall Specific activity < 1 KBq/g No clearance, as expected. At t=100 y the recyclable fraction is 100%, if one considers decay heat and dose rate criteria. Using the operative limit on mass specific activity, the recycling fraction is 0%. The fraction might be, hence, lower or zero. Remarks on BL-FW Mass in kg Up 100,000 y, mass > 1KBq/g = 1.97E+5

Associazione EURATOM ENEA sulla FUSIONE Final Meeting of the Tasks TW5-TSW-001, 001B, October 2006, UKAEA, Culham, UK 17 Work done for D1 Component 50 y

Associazione EURATOM ENEA sulla FUSIONE Final Meeting of the Tasks TW5-TSW-001, 001B, October 2006, UKAEA, Culham, UK 18 Work done for D1 Material 50 y

Associazione EURATOM ENEA sulla FUSIONE Final Meeting of the Tasks TW5-TSW-001, 001B, October 2006, UKAEA, Culham, UK 19 Work done for D1 Component 100 y

Associazione EURATOM ENEA sulla FUSIONE Final Meeting of the Tasks TW5-TSW-001, 001B, October 2006, UKAEA, Culham, UK 20 Work done for D1 Material 100 y

Associazione EURATOM ENEA sulla FUSIONE Final Meeting of the Tasks TW5-TSW-001, 001B, October 2006, UKAEA, Culham, UK 21 Work done for D1 Material 100 y

Associazione EURATOM ENEA sulla FUSIONE Final Meeting of the Tasks TW5-TSW-001, 001B, October 2006, UKAEA, Culham, UK 22 Work done for D1 Material 100 y with LiPb reuse Reduction of 22% of total, of 70% for CRM and of 15% for SRM.

Associazione EURATOM ENEA sulla FUSIONE Final Meeting of the Tasks TW5-TSW-001, 001B, October 2006, UKAEA, Culham, UK 23 Work done for D1 Conclusive remarks Lifetime components (TF, VV and LTS) at t = 100 y are clearable for a share of 66%, the remainder 34% is recyclable, but 27% is > 1 kBq/g. For replaceable components recycling (SRM or CRM) is feasible according to the dose rate and decay heat criteria, but 100 % is >1 kBq/g, making it difficult, if meant for module re-fabrication. More detailed nodalization in the n-transport and activation calculation might reserve surprise and strongly reduce the estimated of recyclable material for replaceable components but not for lifetime components. LiPb reuse may reduce the total amount of activated material of 22%, with reduction of CRM quantity of 70%. A conservative approach based on clearance/recycling of lifetime components only, would lead to 30% cleared/recycled and 70% disposed of. Taking into account LiPb reuse, and effective recycling capability of ~50% of SRM and CRM, the cleared/recycled fraction would be ~70%.

Associazione EURATOM ENEA sulla FUSIONE Final Meeting of the Tasks TW5-TSW-001, 001B, October 2006, UKAEA, Culham, UK 24 Deliverable 6 This deliverable will focus on the application of the RTI (Radio Toxicity Index) for defining clearance levels for radionuclides not included the IAEA Safety Guide No. RS-G-1.7, (but included in the former IAEA TECDOC-855).IAEA Safety Guide No. RS-G-1.7

Associazione EURATOM ENEA sulla FUSIONE Final Meeting of the Tasks TW5-TSW-001, 001B, October 2006, UKAEA, Culham, UK 25 Work done for D6 Comparison between IAEA TECDOC-855 (1996) and IAEA Safety Guide No. RS-G-1.7 (2004) done in task TW5-TSW-002/D1. (for 56 nuclides) 56 nuclides for which, the derived unconditional clearance level was determined by waste handling scenarios and possible exposure pathways

Associazione EURATOM ENEA sulla FUSIONE Final Meeting of the Tasks TW5-TSW-001, 001B, October 2006, UKAEA, Culham, UK 26 Work done for D6 Other 201 nuclides, given by IAEA Safety Guide No. RS-G-1.7, for which IAEA TECDOC-855 provides the values through the formula: where: E  is the effective  energy in MeV and E  is the effective  energy in MeV, as given in ICRP Publication 38; ALIinh is the most restrictive value of the annual limit of intake by inhalation in Bq; and ALIing is the most restrictive value of the annual limit on intake by ingestion in Bq as given in ICRP Publication 61.

Associazione EURATOM ENEA sulla FUSIONE Final Meeting of the Tasks TW5-TSW-001, 001B, October 2006, UKAEA, Culham, UK 27 3 Work done for D6 2 Table 1. Values of Activity Concentration for Radionuclides of Natural Origin [IAEA Safety Guide No. RS-G-1.7] Table 2. Values of Activity Concentration for Radionuclides of Artificial Origin in Bulk 1 21 nuclides + 40 K 257 nuclides 46 included in IAEA TECDOC included in IAEA TECDOC-855

Associazione EURATOM ENEA sulla FUSIONE Final Meeting of the Tasks TW5-TSW-001, 001B, October 2006, UKAEA, Culham, UK 28 Work done for D6 [IAEA Safety Guide No. RS-G-1.7] vs. [IAEA TECDOC-855]

Associazione EURATOM ENEA sulla FUSIONE Final Meeting of the Tasks TW5-TSW-001, 001B, October 2006, UKAEA, Culham, UK 29 Work done for D6 As written in the Studsvik report [N-06/136]: RS-G-1.7 does not provide any method for calculating activity concentrations for not listed nuclides. Even if the number of derived values is much higher than in TECDOC 855 (279 nuclides vs. 56), there are still many not listed nuclides that may be of importance in the context of fusion waste clearance. In the present study Ar39, Hf178m, Hf178n, Cd113m, Sn121m and Ag108m are examples of such nuclides. The attempt to derive clearance levels for the missing radionuclides and compare them with the ones calculated by IAEA TECDOC-855 is shown, considering the relevant radionuclides in the context of fusion waste clearance. As an example we refer to some nuclides ( Hf178m, Cd113m, Sn121m, Ag108m, Al26 and Be10 ). The approach is based on the radiotoxicity index (RTI) already presented in previous studies and here briefly described.

Associazione EURATOM ENEA sulla FUSIONE Final Meeting of the Tasks TW5-TSW-001, 001B, October 2006, UKAEA, Culham, UK 30 Work done for D6 Definition of Radio Toxicity Index #1 Uranium has been the basis of the fission power industry. It is found in nature in concentrations from 0.1 to 1%. As U is radioactive and quite common in the earth’s crust as ore (U 3 O 8 and UO 2 ), it might be used as a benchmark to compare fusion and fission power reactor radwaste.

Associazione EURATOM ENEA sulla FUSIONE Final Meeting of the Tasks TW5-TSW-001, 001B, October 2006, UKAEA, Culham, UK 31 Work done for D6 Definition of Radio Toxicity Index #2 In this comparison assume U ore at 1% ( ˜ 100% U-238). U-238 specific activity = 1.24x10 7 Bq/kg. U ore ( 1% U-238 ) specific activity = 1.24x10 5 Bq/kg. The ingestion dose conversion factor of U-238, relevant to the public, is 4.50x10 -8 Sv/Bq. Hence, the radio-toxicity of uranium ore (at 1%), is 5.60x10 -3 Sv/kg. We define the Radio Toxicity Index (RTI) as the radio- toxicity of any substance relative to that of natural uranium ore. Including U-235 and U-234, and decay products of U-238, U-235 and U-234, the specific activity of 1 kg of U ore at 1% would be 4.61x10 5 Bq/kg (factor  4). Considering the dose conversion factor for U-238, U-235 and U-234 and their decay products the related radio-toxicity would be 2.72 x10 -2 Sv/kg (factor  5).

Associazione EURATOM ENEA sulla FUSIONE Final Meeting of the Tasks TW5-TSW-001, 001B, October 2006, UKAEA, Culham, UK 32 Work done for D6 RTI for PWR spent fuel (due to actinides) decreases with time, as Pu-239 has a “short” half-life, relative to that of U-238 (4.5 billion years). At ~ 480,000 y it becomes the same radio-toxicity of the natural U ore.

Associazione EURATOM ENEA sulla FUSIONE Final Meeting of the Tasks TW5-TSW-001, 001B, October 2006, UKAEA, Culham, UK 33 Work done for D6 The approach with RTI = criteria for clearance provides in general more conservative values than the calculated IAEA TECDOC-855