# Presentation: 116370

## Non-actinide Isotopes & Sealed SourcesManagement Group (NISSMG)

- The **Nuclear Material Integration NISSMG Team** assisted in the disposition of orphan nuclear materials at the Mound facility.  The Mound facility had over 200 grams of 239PuO2 spiked with 0.8% 238Pu and containing approximately 12% 240Pu.  The material was referred to as "APAS material" as it was developed for an Automated Plutonium Assay System.  The containers were packaged in May 1978.  Savannah River Site had agreed to take the material, but there were transportation issues to be resolved.
- NISSMG pulled together a team of technical experts to conduct a gas generation analysis and evaluate DOT and DOE shipping requirements.  Issues have been raised concerning the generation of hydrogen gas from plutonium oxide, for materials in storage and while being transported.  NISSMG substantiated that the materials met DOT requirements for shipping in Type B containers and analyzed potential gas generation rates.

- Complex-Wide Resources Solving Site Specific Problems

- Last of the Major Nuclear Materials Removed From Mound

- The characterization of hydrogen gas generation for the Mound Pu-239 had to be conducted with available historical process knowledge and current x-rays, since even a simple glovebox was not available to support any limited repackaging of the existing containers.  Mound personnel contacted former employees to gain additional knowledge.

*Inner Container Components*

*Containers with 200+ grams of Pu at Mound*

*X-ray of Special APAS Container*

- A methodology was developed to analyze the pressure buildup and hydrogen concentration within the shipping container.  The NISSMG team used bounding calculations with several levels of conservatism for the gas generation, since the history, condition, and moisture of the PuO2 could not be known to ideal precision.

## Results indicated that gas pressure buildup is insignificant compared to the shipping container structure.  Hydrogen concentration was very dependent on the level of conservatism used in the modeling and as a precaution it was recommended that the inner shipping containers be back-filled with an inert gas prior to shipment.

- With this shipment of more than 200 grams of Pu-239, Mound has successfully removed all major nuclear materials from the site.

**The Non-actinide Isotope and Sealed Source Management Group (NISSMG) provides experienced technical personnel who implement innovative solutions using complex-wide resources for site specific issues.**

*Closing the 2R for loading into a 6M shipping container.*

*Monitoring for oxygen depletion while inerting the 2R with argon.*

*6M’s on the truck, ready to go. *
* **FedEx with Pu-239 leaving Mound.*

- For information or assistance from NISSMG contact:
- Jim Low (DOE/AL)
- (505) 845-5458
- jlow@doeal.gov
- Gary Roberson (DOE/AL)
- (505) 845-5805
- groberson@doeal.gov
- Dave Parks (INEEL)
- (208) 522-0486
- dlp@inel.gov
- Gary Polansky (Sandia)
- (505) 845-7029
- gfpolan@sandia.gov
- Ray Finney (Mound)
- (937) 865-3097

- Some of the information on gas generation was based upon efforts to develop a model to estimate the gas generation inside PuO2 waste containers and supported by DOE/AL.