6.1 TASK 5 - SAFETY & RADIOPROTECTION [Give, using the table below, a list of all contractors participating in this Task during the reporting period and the total human effort deployed.] Participants to the Task and total human effort deployed 1 4 7 9 10 11 12 Participant number 6 1) FI UW GANIL CERN NIPNE LMU FZJ Participant short CEA Total-UW name 2) 0 15.75 14.0 6.0 7.0 21.0 4.5 80.05 11.8 Person-months 3) (0.0) (3.75) (6.0) (3.0) (2.5) (0) (0.0) 15.25 (0.0)
[Describe the progress made during the reporting period toward the objectives of the Task and toward the milestones and deliverables foreseen, specifying the contribution of the involved contractors. The contribution of each contractor should be given with sufficient details to allow, in an unambiguous way, to justify the costs declared in part B “management report” of this annual report. Describe any significant achievements, and their impact, resulting from this Task during the reporting period. Clearly highlight and justify any major deviations from the work planned in the contract. Indicate the recommended actions to correct such deviations.] Subtask A: “Radiation, activation, shielding and doses” (CERN): Calculations have been performed to validate the FLUKA Monte-Carlo code for calculations of radioactive inventories. Published experiments for the determination of production cross sections of isotopes in spallation reactions with protons of energies between 300 MeV and 1.8 GeV were reproduced in Monte-Carlo calculations. The calculated cross sections thus obtained were compared to the published data. For light targets, the agreement between published experimental data and Monte Carlo simulations is satisfactory. For heavy target materials such as Au, Pb or U, some areas of improvement of the code were identified. Thanks to the
collaboration with FLUKA authors, modifications have been made in the FLUKA nuclear models so that an improved agreement in the calculated cross-sections for radioisotope production is obtained when comparing to measured cross-sections. Very recent calculations show that now FLUKA cross-sections are in agreement with the measurements within a factor of two for most of the cases of interest for activation calculations. The improved FLUKA version will be made official in the next months and the improvements will be documented in detail in the report in preparation. Fe(p,xn)X à Ep = 1600 MeV
experiment MCNPX
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Fig. 1. (a) – on the left: double differential cross sections of neutron production from p(1.6GeV)+Fe; “default calculation” is in red and “the best calculation” is in blue, both compared to experimental data in black; (b) – on the right: comparison of high energy neutron attenuation in the iron shields as a function of their thicknesses; calculations are represented in smooth lines, while data are in histograms (HIMAC experiment). (CEA): Calculations have been performed to validate the MCNPX Monte-Carlo code for calculations of neutrons, charged particles, photons and radioactive inventories. Model results were compared to existing experimental data in the energy range as defined in EURISOL DS, and also for target materials to be used in EURISOL DS. In most of the cases agreement with data is acceptable as long as the adequate models are chosen (see Fig 1a). In this context the best model combinations were identified and will be employed for further studies
on realistic target geometries. Monte Carlo simulations were performed with MCNPX (FI) and FLUKA (NIPNE) for comparison with available data on neutron and photon attenuation (HIMAC benchmark) including some basic neutron shielding studies. In brief, both codes can provide acceptable estimates and will be used for the shielding design (Fig. 1b). The code FLUKA was also examined (WU) in comparison with the experimental spallation data obtained by NESSI collaboration. The measured neutron multiplicity distributions per event show some disagreement compared to the FLUKA predictions. It was observed that the average number of neutrons emitted in a single spallation reaction fit to the data, but the shapes of the experimental and simulated distributions are different. Similar test calculations were also done with MCNPX (CEA). The authors of both FLUKA and MCNPX are informed about the outcome of this benchmark. Independently on these results we note that the double
differential cross-sections for neutron production (which is relevant for radiation protection studies) are well reproduced both by FLUKA and MCNPX. All above efforts serve as a milestone M1.1 “Validation of the MC codes” (considered to be finished by now). This milestone was achieved in collaboration with Tasks 4 and 11, where code validation was also indispensable. Another milestone M1.2 “Radiation & activation estimates” is also slightly delayed. The expected date for completion of it is shifted into year 2 mainly because the useable lay-out of the multi MW targets for the radiation protection estimates became available only during summer 2005. Nevertheless, studies relative to this
milestone have started and progressed already. This is the most challenging part of the facility from the radiation protection point of view. For the time being, values of shielding parameters have been determined and more detailed studies will evaluate further the radiation protection design parameters. Solutions resulting for this station will be usable also for the 100 kW targets and tailored to these lower power stations, once their lay-out is available. As soon as the work on the multi MW target is completed, radiation protection estimates for the 100 kW direct target stations can be done. Therefore, their preliminary design parameters need to be ready by the mid-2006. In addition, a significant progress was achieved in collection of data relative to the activity in the MW Hgtarget and to the radio-toxicity and to the conventional toxicity of mercury (Fig. 2a). A preliminary progress report is in preparation and will be ready soon (FZJ). Equally, first steps were undertaken concerning the shielding guidelines for the EURISOL driver accelerator (FZJ, CERN). A report on EURISOL shielding items based on ESS shielding experience is in progress and will be finalized about June 2006. For the activation of ground water, activation calculations for different soils were performed and compared (FZJ). Two external partners, namely ORNL (USA) and TRIUMF (Canada), have contributed to the project by giving presentations, participating in discussions and sharing relevant material during the last working meeting of the task (T5-03-CEA-27-28.10.05). Most of the information, related to safety and radioprotection issues from these partners, has become available for Task 5 thanks to this collaboration. Subtask B: “Radioactivity, control, safety and risks” No milestones were to reach during the 1st year. Study of containment of radioactivity has progressed with the following achievements (LMU): 1) Cryopanel was installed within test bench at Garching MLL accelerator laboratory, 2) Cryopanel was coupled to newly-installed liquid-He transfer line to He refrigerator, 3) First cooling test with cryopanel was successful, 4) Thermal sensor equipment prepared and tested for installation (see Fig. 2b). As long as migration of ground water is concerned (milestone M2.4), model creation and validation is in progress (FZJ). The collection of sorption coefficients for relevant nuclides in soil was prepared and will be ready as an interim report shortly (FZJ). Although there is some delay in this particular milestone, we expect the achievement of it at the end of 2006. (FI) should join this action in the nearest future. For the milestone M2.1 “Dispersion of Radioactivity” an integrated software platform has been development containing data libraries and key methods for the radiological assessments of the health and environmental impacts of accelerator facilities seen from the perspective of the NPP/nuclear fuel cycle experience (NIPNE). It will include the problems related to the handling and disposal of radioactive targets, containment failure scenarios, activity migration, specific radioactive inventories, risk assessments, etc. (NIPNE). Some more experience related to accelerator induced radioactivity will be gained from the ongoing project SPIRAL2 (GANIL).
Fig. 2. (a) – on the left: comparison of total nuclide inventory in the MW Hg spallation target and research reactor; (b) – on the right: photo of the fabricated prototype cryo-trap for the containment of radioactive gases. Subtask C: “Decommissioning” No actions were planned during the 1st year. However, oxidation behavior of target materials in accidents and storage cites was already analyzed (FZJ). In addition, with respect to disposal items, a PhD thesis was started with the title ‘Disposal strategy for the EURISOL liquid mercury target’ (FZJ). Some information was also collected from the experience gained in dismantling research reactors and particle accelerators (CEA). Subtask D: “Conformity to legislation” No actions were planned during the 1st year. On the other hand, some information was already collected on legislation issues of mercury metals in different countries (FZJ). In addition, GANIL has requested to advance this work due to practical and organizational reasons, i.e. this subtask becomes “active” in 2006. Other issues In general, the procedure finding good candidates to employ for the project were delayed (e.g., CEA, WU, LMU, FZJ). This situation together with the fact that other tasks were not ready to provide the reference parameters by late 2005 resulted that some of the milestones are going to be reached somewhat later. However, these temporary delays are not crucial anymore for the future of the task, what means that the work in general will continue as planned. Finally, Task 5 hopes for a better collaboration with other tasks, in particular in obtaining requested information to progress in radiation protection and safety issues.
[List in the table below all milestones and deliverables defined in the contract that have been achieved during the reporting period.] Milestones and deliverables achieved during the reporting period ** Deliverable/
** Deliverable/Milestone Name
Milestone No M1.1
Validation of MC codes
** Workpackage
** Lead
/Subtask No
Contractor(s)
5/A
** Planned (in months) 6
Achieved (in months)
CERN, CEA, 12 NIPNE, WU, FI M1.2 Radiation & activation 5/A CERN, CEA, 12 18 estimates NIPNE, WU, FI The deliverables have to be annexed to this table (see Deliverable Template). When the deliverables are not a report provide any available supporting material that can document them (e.g. photographs of a prototype).
[List in the table below the major meetings and workshops organised under this activity during the reporting period] TASK meetings and workshops Date 28.01.05 07-10.06.05 27-28.10.05
Title/subject of meeting T5-01-CERN-28-28.01.05 T5-02-CEA-07-10.06.05 T5-03-CEA-27-28.10.05
Location CERN CEA CEA
Number attendees 13 11 37
of
Website address http://eurisol.wp5.free.fr/ http://eurisol.wp5.free.fr/ http://eurisol.wp5.free.fr/
1) Lead participant first. 2) Use the same contractor short names and numbers indicated in the table “list of participants” in Annex I of your contract. 3) AC contractors must include both the total estimated human effort (including permanent staff) and, in brackets, additional staff only.
