Nuclear CookiesClient: Idaho National Lab Project: Salt Removal

Problem Statement

During normal operation an electro- refiner produces a small amount of plutonium that builds up. When the plutonium concentration gets too high a portion of the salt must be removed. The scope of this project is to remove a volume of salt from the ER and parse it into appropriately sized cubes for transport to a grinder.

Mock-up of ER

Once we have a solid lead on which route we are going down we can use this mock-up to simulate things like the bucket lowering into the ER, or the conveyor removing something like water from the tank below.

Will have metal plate over this hole with a more precisely machined hole

Pulley/Conveyor Concept

1. Individual cube containers scoop out salt

2. Cubes are transported using a conveyor system

3. Salt freezes on the way up

4. Cubes fall out on the way down

5. Cubes slide down on ramp to storage container

FreezingRange

Pulley System

Advantages•High upside (can remove required amount of salt in about 7.5-15 hours once it starts running) •Can run continuously (don't have to wait for salt to freeze) •Can remove all salt from electrorefiner •Very little handling while operating •No complex parts to machine

Disadvantages•Most complex design with most number of parts that can fail •Fits our specs the worst •Messy due to salt freezing on chain then getting broken off by pulley •Heat can escape from electrorefiner due to holes needed in cover •Most difficult to perform maintenance on 5

Venturi Concept

1. Argon is pulled through the blower and blown through the venturi.

2. Argon flow through the venturi creates a negative pressure and draws up molten salt through draw tube.

3. Salt atomizes upon leaving venturi and freezes into a powder.

4. Salt goes through a cyclone separator to lose velocity then falls into container

Venturi

Disadvantages•May not be within budget anymore•Can’t prove it will atomize salt•Long set-up time•Salt could freeze in drawtube•Most difficult to make work

Advantages•Completes the extraction and freezing in one step.•Could be used for removing all molten salt •Could be run continuously (don't have to wait for salt to freeze) •Very little handling involved while it is running•Uses only one 4 in diameter hole

Bucket-Tray Concept

1. Bucket is lowered into electrorefiner2. Molten salt fills bucket3. Bucket is taken to trays and emptied (by valve or pouring)4. Salt freezes into cubes and trays are dumped into containers.

Bucket-Tray System

Advantages•Simplest design •Uses already proven concepts •Lowest set-up time •Fits our specs the best •Allows for more versatility in design

Disadvantages•Requires the largest storage area •Most handling intensive while operating •Can only draw out molten salt if the level is above 16 in from bottom •Salt can freeze moving parts •Have to insulate bucket

Tray Ideas Designs Center Around:• Use on the table top in the hot cell where the existing design is emptied• Handling the amount of salt provided by the bucket from either one or

multiple dumps • Reducing the handling for getting cubes into the container • Getting salt to freeze into the required shape• Safe against Spilling

When the salt is dry the tray will be removed and replaced with the container that carries the salt to the grinder

Any spills are contained and go into the tray beneath

Enough capacity for one bucket load of salt