Facility readiness evaluation for High-Z experiments at the NIF. (b)(6)

Transcription

1 Facility readiness evaluation for High-Z experiments at the NIF (b)(6)

2 Facility Readiness Overview Evaluated the use of High Z materials from a Safety Basis / SWEIS and worker safety point of view Results indicate that it is feasible to deploy these targets but is dependent on: Mass and isotopics of the target material Target debris catcher efficiency Additional operational equipment Evaluated target transport, handling and recovery No significant facility modifications anticipated Procedural modifications will be necessary Evaluated designs and concepts for target debris catchers Catcher is necessary to reduce inventory, impact on long-term operational efficiency, and worker exposure potential 2

3 Facility Readiness Overview, Continued Details/impacts of some aspects have not yet been evaluated Diagnostics loop Optics loop Support services (e.g. bioassay program) It is essential that we start to maintain configuration managed point designs for each platform as we proceed with this project Directionality of ejecta was not evaluated, and this could further limit allowable target parameters or required catcher efficiency Experiments are needed to evaluate target ejecta/performance 3

4 NIF Hi-Z Target Experiments - Concept of Operations Hi-Z Targets fabricated outside of NIF and delivered individually prior to the shot Targets transported using standard LLNL Protocols Upon arrival at NIF, material entered into NIF s Inventory Mass/Isotopic make up provided by WCI Alpha contamination protocols fully implemented Target Loaded/catcher deployed 4

5 NIF Hi-Z Target Experiments - Concept of Operations (cont.) Experiment conducted Target, catcher and diagnostic assemblies retrieved using alpha protocols Target/Catcher assembly returned to WCI Requirement: WCI conducts assay to determine residual mass and its isotopics NIF is notified with residual mass analysis and NIF inventory updated 5

6 Operating Envelope for High-Z Materials Safety Basis Limits total amount of material in the Target Chamber at any given time Worker Safety Surface Contamination: limits isotopics and amount deposited per target Impact of High-Z material based on: 1) Containment and capture efficiency 2) Radionuclide mix 3) Mass of target 6

7 Limitations and Constraints - Safety Documentation Safety and Environmental Documentation SWEIS Limits the amount of material allowed in the Target Chamber Forms basis (source term) for public impact from catastrophic incident Does not allow use of WG without containment Safety Basis Falls within SWEIS Limited to 100 mg WGE total in the chamber Declares NIF as less than Category 3 (non-nuclear) facility Safety Basis Limits may be approached as material (dispersible or intact) accumulates within the Target Chamber 7

8 Limitations and Constraints Worker Safety Aspects Workplace type (glovebox, hood, etc) Positioners, etc. are Type 2 Work Place negative-air enclosures We expect to be well below the Type 3 Work Place (glovebox) threshold Continuous air monitoring system (CAMS) for alpha Currently not installed in the facility Portable instruments will be used Target throughput limited so that permanent CAMS not required Contamination Guideline for Entrant Components Levels to support campaign and hardware design identified Design driver Higher contamination levels within the Target Chamber are thought to be manageable 8

9 Limitations and Constraints Other aspects appear to be non-limiting Criticality Well below thresholds Accountable material control Well below thresholds Environmental monitoring Existing stack monitoring equipment is fully capable TRU waste Estimates indicate we will not produce TRU waste Managing contamination on Entrant Components is Limiting (hazard control) 9

10 Personnel Protection Alpha Contamination Management Handling positioners and associated components is routine therefore, we need to be confident that we can manage these levels on an ongoing basis Positioners not designed to act as glove boxes, but are negative air enclosures therefore, there are limits to contamination levels that can be safely managed in this environment Positioner max removable contamination criteria (Alpha) 2x10 4 dpm/100cm 2 Small, discrete item max removable contamination criteria (Alpha) 2x10 6 dpm/100cm 2 Directionality of ejecta could impact estimated contamination levels and will need further evaluation 10

11 Personnel Protection Contamination Management High-Z operations would add: Respirators Personal air samplers Components covered/bagged Routine decon/wipe down Alpha monitoring Provides real-time feedback on contamination levels Current contamination control practices 11

12 Personnel Protection Contamination Management Two gloveboxes are available in the Hazardous Materials Management Area Activation will take ~ $0.5M and approx 6 months Gloveboxes may be required for disassembly and/or decontamination of removed items 12

13 High Z Targets & Assumptions Potential Targets evaluated 8 mg, 4.5 mg 100% 242 mix 242 mix + 1% WGE 0.7 mg, 0.15 mg Assumptions 100% 242 mix 242 mix + 1% WGE 100 % WGE, Evaluated but not permissible under SWEIS Am-241 removed from 242 mix at time of fabrication Hi-Z materials will not be subjected to neutron yields Target Chamber will not be cleaned/de-inventoried, but entrant components are cleaned between shots Ablated material uniformly distributed 13

14 Allowable High-Z Materials Evaluation Results Ripple Target This plot assumes the full allocation (50% of the SB) is used for this target type 14

15 Allowable High-Z Materials Evaluation Results Stepped Target This plot assumes the full allocation (50% of the SB) is used for this target type 15

16 Allowable High-Z Materials Evaluation Results Flat Target This plot assumes the full allocation (50% of the SB) is used for this target type 16

17 Allowable High-Z Materials Evaluation Results All Targets Small Diffraction Large Diffraction RT and EOS For a combination of targets, the sum of the ratios of actual number of each target to its limit must be less than 1 17

18 Allowable High-Z Materials Evaluation Results large targets # of shots to reach limit (b)(5) Larger targets require high catcher efficiency 18

19 High-Z Materials Preparations and Start up NIF Follows Work Authorization Point (WAP) process to authorize work Identifies the set of items to be completed before authorization Facility Preparedness Equipment acquisition Procedure development/modification Personnel training Necessary additional resources: Alpha contamination monitors Portable continuous air monitors NIF Glove Box commissioning (if required) Management Prestart Review (MPR) Independent review of readiness Other Impacts need further evaluation Optics (Purged storage and B391 OPF/OMF), Diagnostics, lab support 19

20 Catcher high level requirements and assumptions Catcher minimizes NIF inventory and worker exposure potential Resources need to be allocated to design catcher Material to be returned to WCI; material specification / format not yet defined Capture efficiency requirements TBD; detailed requirements not defined May vary by target type and target assay Amount captured must be quantified to allow removal from inventory Accuracy may depend upon efficiency achieved and margin to limits Larger mass targets require an effective catcher 20

21 Catcher high level requirements and assumptions Catcher must survive anticipated debris, 1w, and x-ray load for energy ranges of interest for campaigns Assume deployed on existing NIF positioners; may require new payloads/end effectors Target must fit in TAS for alignment; adequate alignment DOF s must be available to align target, backlighters and catcher Catcher may or may not be co-located with target; may be distributed to meet requirements Must meet NIF TC operational criteria: material compatibility, handling limitations, shot cycle interfaces, align-ability and stability 21

22 Catcher design status and issues Strength/EOS campaign catcher design status: There currently is NO mature concept for a catcher that meets fundamental requirements Both survivability and capture efficiencies are issues Significant modeling is required to predict material dispersion and distribution Interplay between target, required diagnostics and catcher is complicated Timely recovery of diagnostic data may determine where post-shot activities occur Diffraction campaign catcher design status: The lower energy and target mass of TARDIS design improves likelihood that catcher requirements could be met for this campaign TARDIS experiments in CY13 will provide some relevant information Significant modifications of the base design are required for planned campaigns Catcher design would benefit from use of surrogate material during testing (see next slide) Limited 1 st principle concept testing is starting on Omega in May Initial use of small targets facilitates phased catcher development 22

23 Catcher testing and validation To validate performance of a catcher, test shots with a TBD surrogate material may be required Captured material measurement techniques may include: Mass measurement Activity measurement Chemical separation with one of the above Others? Surrogate material must: Have similar melt/vaporization response to planned target material Be differentiable from other NIF target/tc materials Be consistent with chosen measurement techniques (e.g., may need to be radioactive to test radio-assay technique) Surrogate development must be pursued in concert with catcher design 23

24 Preliminary proposed catcher development schedule Catcher development needs to be organized as a full project 24

25 Diagnostics have been identified for High Z experiments Diagnostic Experimental platform Issues (b)(3) SuperSnout II (0, 0) Diffraction, Strength (b)(3) Potentially contaminated image plates and hardware Dante I (143, 274) Diffraction, EOS, Strength Connected to TCV (b)(3) (b)(3) SXI U/L Diffraction, EOS, Strength (b)(3) Requires new snout configuration for diffraction Potentially contaminated hardware (b)(3) (b)(3) FABs EOS, Strength None, No contact with TCV NBI EOS, Strength None, No contact with TCV FFLEX Strength (EOS optional) None, No contact with TCV EHXI Strength (EOS optional) None, No contact with TCV

26 Diagnostics design and interfaces No new diagnostic designs are required Diagnostic to catcher interface could require engineering design TARDIS could be integrated Others are more difficult Post shot diagnostic handling protocols need to be developed DIM diagnostics (HEIDI, GXD, VISAR) SXI s Dante Protocol would follow Be handling protocol as an example Decontamination of data media will need consideration Setup contaminated Image plate reader Decontaminate Image plate and read clean Contamination levels will determine process

27 Process diagram for target diagnostic components Shot RI selects diagnostics in CMT Diagnostic assembly in standard NIF factory Diagnostic LRU s loaded into respective locations NIF shot generating WPE Connected to TCV Yes No Process as normal Follow contamination protocol Survey diagnostic components Alpha contamination on Parts? Yes No Process as normal Recover data media in glove box Decon media Decon parts or Dispose Process as normal

28 Action Items - Engineering Engineered controls preferred over PPE/Admin controls e.g. Local enclosures Consider redesign of entrant components (e.g. snout) to ease decon Specification of Capture efficiency should be avoided Develop FMEA Evaluate oxide forms Evaluate effects of Hi-Z materials on image plate 28

29 Action Items - Administrative Evaluate operational impact on non Hi-Z shots Define protocols for non Hi-Z shots Evaluate human factors (worker proficiency, training, skills, etc.) Clarify material limits based on state (solid, liquid, vapor) 29

30 Action Items - Communication Develop communication strategy (b)(5) 30

31 Facility Readiness Overview Evaluated the use of High Z materials from a Safety Basis / SWEIS and worker safety point of view Results indicate that it is feasible to deploy these targets but is dependent on: Mass and isotopics of the target material Target debris catcher efficiency Additional operational equipment Evaluated target transport, handling and recovery No significant facility modifications anticipated Procedural modifications will be necessary Evaluated designs and concepts for target debris catchers Catcher is necessary to reduce inventory, impact on long-term operational efficiency, and worker exposure 31

32 Facility Readiness Overview, Continued Details/impacts of some aspects have not yet been evaluated Diagnostics loop Optics loop Support services (e.g. bioassay program) It is essential that we start to maintain configuration managed point designs for each platform as we proceed with this project Directionality of ejecta was not evaluated, and this could further limit allowable target parameters or required catcher efficiency Experiments are needed to evaluate target ejecta/performance 32

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