Tritium Systems Test Assembly (TSTA) D&D Experience and Progress

Scott Willms, Chuck Tesch, Roy Michelotti,Richard Carlson and Mike RogersLos Alamos National Laboratory

Experience in the management ofwastes from fusion facilities

JET

March 25-26, 2003

LA-UR 03-2320

Outline

• TSTA Shutdown Overview• Tritium inventory reduction approach

– Bulk gas– Tritiated water– High inventory components

• Tritium surface concentration measurements• Tritium gas phase concentrations

Outside view of TSTA

TSTA consisted of over 15 interconnected systems (in and out of gloveboxes) dedicated to various purposes

South-looking view of TSTA test cell

Test celllooking north

TSTA Overview

• Objective: Develop and demonstration fusion fuel processing systems in an integrated facility

• Operating Years: 1984 – 2001• Tritium Inventory: Was ~140 gm, now <1.6 gm?• Flowrate: About 1/10th ITER• Program Completion: In November, 1999 a DOE review

determined that the TSTA program was complete and that the facility would be shutdown

Stages of TSTA shutdown

• Stabilization: Remove TSTA tritium to below 30 gms (Cat III nuclear facility) and then to below 1.6 gms (radiological facility)

– Performed by SC– Expected to complete in June, 2003– EM agrees to transfer endstate. When met, transfer ownership to

EM• S&M: Hold in surveillance and monitoring mode

– Waiting in “safe and stable state”.– Little/no work. Minimal budget.– 0-10 years

• D&D: Perform Decontamination and Decommissioning– When budget obtained, take to “bare walls” or “slab on grade”

0

20

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140

Triti

um In

vent

ory

(gra

ms) Hazard Category II

>30 gramsSerious Public Risk

Hazard Category III1.6 to 30 gramsLimited Public Risk

Radiological Facility<1.6 gramsRisk to Workers Only

--Lethal Dose 0.001 grams

--Highest TFTR Inventory <5 gm

--Present TSTA Inventory 129 gm

TSTA: A category II nuclear facility

“NonReactor Nuclear Facility means those activities or operations that involve radioactive and/or fissionable materials in such form and quantity that a nuclear hazard potentially exists to the employees or the general public”

--DOE Order 5480.23

--TSTA Inventory in 2000

Recent Major TSTA Stabilization Project components

ID Task Name

2 Bulk Gas Removal3 Fill & Ship HSV24 Disposition remaining gas5 Moisture Collectors6 Dispose of present collectors7 Disposition future collectors8 Glovebox Stabilization9 Four shutdown10 Six shutdown11 Nine shutdown12 Fifteenth shutdown13 Support Systems14 Shutdown present TWT15 Disposition MDAC16 Transfer TSTA from SC to EM

3/13

ay Jul Sep Nov Jan Mar May Jul Sep Nov Jan Mar May Ju2002 2003

Tritium form 1 of 3: Usable “bulk tritium”

• About 2500 standard liters of hydrogen isotopes contained about 70 grams of tritium

• Gas was consolidated on five uranium beds (one shown)

• This was transferred to three long-term, titanium storage beds. Two were shipped to Savannah River and the third, with 2000 Ci, was disposed of at LANL.

Tritium form 2 of 3: Tritiated water waste

• About ~34 grams of tritium existed as water adsorbed on molecular sieve contained in 15 gal containers

• These were packaged and buried at the LANL waste repository

• Pressure vessel rated packages were expensive

Tritium form 3 of 3: “High Inventory Components”

• There were about 40 components containing tritiated high surface area materials and hydride materials

• Together these components contained about 13 grams of tritium

• These were decontaminated, characterized, packaged and buried

Waste inventory methods used

• Direct Liquid measurement: Liquid sample, scintillation• Direct Gas measurement: PVT-mass spec• Integration: Ion chamber * flowrate integration• Bulk estimate based on weight: 5 Ci/Kg for low surface area

tritium wetted components• Exchange: Hydrogen exchange/hydrogen analysis• Calorimetry: Measure heat of decay to infer tritium content • Regeneration: Regeneration of water/mass spec of water• Soak: Soak material in water/scintillation on water sample

TSTA stabilization high inventory component waste summary

System Description # items T Content (gm)

-Tritium recovered from components was converted to water in TWTTWT Molecular Sieve Molecular sieve generated during stabilization 21 7.06

-Tritium remaining in components when they were disposedPMR Catalyst, Pd/Ag tubes 3 0.27JFCU Catalyst, Pd/Ag tubes, ZrCo 4 0.09Misc. Catalyst, hydrides, equilibrators, oil, etc. 8 0.32UTB Beds Depleted uranium from main storage system 5 0.03FCU Molecular sieve, Mg, Catalyst 10 3.61Processing components General processing components @ 5 Ci/kg 31 1.10

Total 12.48

Approximate tritium removal summary

Category Tritium Removed (gm)Bulk Gas ~70Tritiated Water-legacy ~34Tritiated Water-stabilization ~7High Inventory Components ~6Total ~117

Tritium contamination on inside glovebox surfaces: Before and after stabilization activities

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T Su

rfac

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EXP-3ISS-GANTPOPPMRLIOISS

Tritium contamination on typical valve after stabilization: inside and outside surfaces (note that inside surface had smaller area swiped)

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1 2Valve Swipe Location

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Outside Inside

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ck T

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icro

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Glovebox

Stack

FCU glovebox and stack tritium levels during D&D: Interior water misting with TWT processing used to minimize stack releases

GB open to stack

Water added to GB

Conclusions

• TSTA stabilization is nearing completion• The three major categories of tritium inventory reduction were:

– Bulk tritium– Tritiated water– High inventory components

• Data have been collected on tritium surface concentrations and glovebox atmosphere tritium concentrations during stabilization operations

• High inventory component tritium inventories have been determined using a variety of methods