Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.

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Tritium Gas Analysis Capabilities and Results from Sandia National LaboratoriesRussell Jarek, Henry Peebles, Jessica Bierner37th Tritium Focus Group Meeting, October 26, 2016

Capabilities Overview Quantitative measurement of permanent gases, particularly including 

the hydrogen isotopes (HDT) Thin film desorption Gas cylinder samples  Grab samples from sealed systems

Calorimetry Bulk tritium quantitative measurement Waste stream

JEOL M‐Station High‐res & high‐mass Various sample inlet options

2

Outline

Requirements for Quantitative Mass Spectral Analysis

Mass Spectrometer

Stable instrument ion source and detector

Gas Standard(s) for detector sensitivity calibration

Sufficient mass resolving power

Total molar quantity measurement

Stable in‐situ pressure measurement (Baratron CP gauge)

Calibrated source of molar quantity gas

Calibrated leaks and accumulation time

High‐precision pressure gauge in known volume

3

4

0 5 10 15 20 25 30-2.0

-1.5

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

-2

Rel

ativ

e D

rift f

rom

Prio

r D2 S

ensi

tivity

(%)

Pre-Analysis Calibration RunsMay 2016 - Oct. 2016

+2

Mass Spec Sensitivity Stability

HDT Standards and Measurement

• In a environment which provides a mechanism for dissociation, the hydrogen molecules exchange isotopes to establish thermodynamic equilibrium.

H2 + D2 ↔ 2HD H2 + T2 ↔ 2HT

D2 + T2 ↔ 2DT

• The mass spectrometer measures each of the six molecular isotope species. Given initial H2′ , D2′ , and T2 ′, the concentration of the six molecular isotopes can be calculated from the equations from known equilibrium constants (Jones 1949 & 1967):

)D()H()HD(

22

2

XXXKHD

)T()H(

)HT(

22

2

XXXKHT

)()()(

22

2

TXDXDTXK DT

@ 298 K: 3.26 2.57 3.82

• Mass spectrometer sensitivities are calculated from the HDT primary standard spectra using the equation for each ith molecular species:

• Molar quantities of the molecular isotopes in unknown samples are determined using a rearrangement of the same equation, solving for (Xi · nT), the mole quantity of ith species.

• H2′ , D2′ , and T2′ are calculated using the mass balance equations.

Ti

ii nX

IS

HDT Standards and Measurement

)HT()HD()H()́H( 21

21

22 XXXX

)DT()HD()D()́D( 21

21

22 XXXX

)DT()HT()T()́T( 21

21

22 XXXX

HDT Standards and Measurement

3.005 3.010 3.015 3.020 3.025 3.030

0

2000

4000

6000

8000

TCV-04

HD

3He

20X

Inte

nsity

(mV

)

Atomic Mass Units

1X

T +

Determine nT by Pressure-Volume StandardParoScientific 6000-15A

8 to 775 Torr, 3.7 mLTRnVP

Precisely (0.1%) measures and internally captures a known molar quantity of gas.

Gas expansions measure internal effective volumes (n / P) of adjacent vessels.

Good absolute accuracy (1%, 2) of measured “N/P” functions transferred to Baratron response

eff,ff

oo VP

VP

PnTR

V /eff

Desorption Calibration Curve for Inlet System

...

C

AC

B

ABA

A

AT T

TVTTVV

RTPnRather than:

systemN/P PPnT Just:

System Check – N/P Control Chart

2/1/2005 5/1/2005 8/1/2005 11/1/2005 2/1/2006

-1.0

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

LCL (-0.8%)

%

in N

/P R

elat

ive

to C

alib

ratio

n E

quat

ion

Date

PV-STD TC Readout Changed

Furnace TCChanged BJ Changed

Furnace TCReadoutAdjusted

BJ Shifted

BJ Changed

UCL (0.8%)

11

HDT Gas Standard Comparison

10/1/2014 2/1/2015 6/1/2015 10/1/2015-1.0

-0.5

0.0

0.5

1.0

H/D 77 / 79 T/D 77 / 79 H/D 77 / 80 T/D 77 / 80

Pe

rcen

t Diff

eren

ce

Measurement Date

TCV-77 (5-65-30) TCV-79 (35-35-30) TCV-80 (10-80-10)

Thermal Battery Internal Gas Sampling

13

Li(Si)/FeS2 Thermal Battery Aging Study• Battery-like units built with modern production

process, material of known pedigree (and stored)• Two acceleration factors selected

– Temperature (classic Arrhenius)» Temperature selections based on historical

accelerated aging levels (1980’s testing)– Water

» Only confirmed aging mechanism for thermal batteries is water reaction- forms basis for leak rate measurement

» Leak rate can’t be easily controlled, so water was added to the battery instead

• Times selected for convenience

Variable LevelsTemperature 75°C, 130°C, 180°CTime 3m, 6m, 12m, 24m (75°C only)Water content Dry to best efforts, insulation exposed to moist air

Battery‐like unit• All battery materials except 

ignitor or heat paper• Fiberfrax insulation• Stack shimmed to 250 PSI• Welded stainless steel can

14

Thermal Battery Internal Gas from Aging Study

15

Thermal Battery Internal Gas from Aging Study

Calorimetry For Non-Intrusive Tritium Measurement

Sample Well12”x12”x30”

Tritium Capture System (TCS) absorbs tritiated waste onto molecular sieve bedsProblem: To maintain regulatory compliance for disposal, the amount of tritium in the sieve beds must be declared.

Calorimeter

Other Uses:- Helps to check reported tritium inventory- The 100% tritium bottles are usable as calibration standards for the calorimeter - First TCS waste sieve bed measurements made in FY16

0 1 2 3 4 5 6

0

5

10

15

20

25

30

Hea

t Pow

er (m

W)

Signal (mV)

Equation y = Intercept + B1*x^1 + B2*x^2Weight No WeightingResidual Sum of Squares

1.05389E-5

Adj. R-Square 1Value Standard Error

BIntercept -0.00227 0.00255B1 5.15779 0.00227B2 -4.54516E-4 3.5701E-4

Calorimeter Calibration Curve

Technology: Differential heat-flow from the radioactive decay produces a voltage that is proportional to the quantity of tritium in the container cell vs. reference cell.

JEOL M-Station Mass Spectrometer

0 100 200 300 400 500

5.0E+06

1.0E+07

1.5E+07

2.0E+07

68.9

7

119.

013

1.0

169.

018

1.0

219.

023

1.0

269.

0 281.

0

331.

0

C2F5

C7F13

C6F11Inte

nsity

Mass

CF3C3F7

70 80 90 100 110 1201E+04

1E+05

1E+06

1E+07

68.9

7

119.

0

C2F5

Inte

nsity

Mass

CF3

• Resolution, R ≥ 60,000, 10% valley between peak responses

• Mass Range: Up to 24,000 m/z at 1kV• Liquid/Gas/Solid Probe MS inlet options• Agilent 6890N Gas Chromatograph for

GC-MS operation (Installation in Progress)• Planned sample types: Hydrocarbons,

Fluorocarbons, Siloxanes

∆

Where R: ResolutionM: Mass Number

∆M: Peak Width