hazard classification of the remote handled low-level waste disposal facility

May 9 2012

Hazard Classification of the Remote Handled Low-Level

Waste Disposal Facility

Boyd D. ChristensenBattelle Energy Alliance, Idaho National Laboratory

P.O. Box 1625Idaho Falls, Idaho 83415

208-526-7914boyd.christensen@inl.gov

Remote Handled Low Level Waste Disposal at INL

• The INL consists of a number of different research complexes conducting science and engineering solutions to nuclear energy development programs

• Many of these programs generate RH LLW.• Current disposal is at the Radioactive Waste

Management Complex (RWMC) on the INL site.• RWMC is scheduled for closure within the next 3-5

years

INL Facilities Generating RH LLW

• Materials and Fuels Complex (MFC)– Hot Fuels Examination Facility– Fuel Conditioning Facility– Analytical Laboratory– EBR-II Legacy waste in temporary storage

• Advanced Test Reactor (ATR)– Reactor component hardware– Reactor system resin beds

• Naval Reactor Facility (NRF) Expended Core Facility– Reactor component hardware– Reactor system resin beds

Alternatives for RH LLW Disposal

• Nevada National Security Site – smaller cask, more shipments (>100/yr), 1420 miles r/t, 25000 population along travel corridor, greater risk

• Commercial disposal facility – program risks

• INL RH LLW disposal Facility** - “out of commerce” transportation, use of existing cask systems, no population, lower risk

• No action – INL R&D mission impact, national security impact**Highest ranked alternative for INL RH LLW disposal

INL Geography and proposed facility location

Facility Concept

Disposal Vault Concept

Cask Operations

Cask Operations

Cask Operations

Cask Operations

Cask Operations

Facility Closure Concept

Waste Streams

• LLW solids– <100 nCi/g TRU elements– > 200 mrem/hr– Anticipate up to 60,000 R/hr– <15 g fissionable material per disposal vault– No liquids allowed

• Waste packaged in SS canisters in generating facilities then transferred by shielded cask to disposal facility

Facility Hazard Categorization

• Following DOE-STD-1027, preliminary HC based on entire facility inventory (only modification is exemption of sealed sources meeting specific criteria)

• Final HC can be performed considering 1) alternate release fractions and 2) change in material subject to an accident due to facility features that preclude bringing material together or causing harmful interaction from a common severe phenomenon(facility segmentation)

Preliminary Hazard Categorization

• Simple screening step to identify likely hazard category

• Consideration of form, location, dispersibility, and interaction with energy sources are not given

• Sealed sources may be exempt from inventory for HC; fissile material in sealed sources not excluded– Special form criteria; DOT, NRC, ANSI

Final Hazard Categorization

• Modification of TQs– Alternate release fractions used for “obvious gross

inconsistency”– Potential to increase HC based on higher dispersible form or

interaction with energy source

• Facility Segmentation (2 cases)1. A multiple structure facility – physically separated structures

(example: multiple storage bunkers with one common safety basis [one facility])

2. A single but segmented facility – internally divided into non-interacting segments

Hazard Categorization for RH-LLW Disposal Facility

• Preliminary HC; HC-2 nuclear facility – based on total facility inventory

• Final HC; consideration for facility segmentation results in HC-3 sum of fractions

Is Lower HC Better?

• What are benefits of adjusting (lowering) HC?– Simpler safety basis development

• What are the risks associated with lowering HC?– Risk of exceeding TQs if HC-3– May limit future operations and waste streams

Conclusion

• For the RH-LLW disposal facility at INL no significant cost savings in downgrading HC

• Does not change the facility Performance Category or QA requirements (SDC drives design)

• No real benefit or advantage (but some added risk) identified for downgrading HC

• Initial HC-2 classification to remain in effect