TITLE:

I

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AUTHOR(H): Don O. Coffin

WEiMIITED?’C): Proccedlngs of 24th Conference on

Remote System Technology, 1976

By mreptunrv or tblm nrclclr for puhilcwflwt. ihrpubll~hvr rrco@zm the Ciovvmnwntms~llcenw) rlght~in unJ copyrlmhtund Ihv Govvrnmwtt and It* authorlmdr~tati- Imve unreetrlctd rlxht to rrprdm Inwhol~ or in ~rt neld artlds undm nny copyrlmhtorvurvd hy Lhv publhdwr.

Thv LowAhI- Hrlrnllflc Iaburatory rvqmlm that th~puhllAwr ideitIi@ this ttRlrlF ESwurk perfnrmwl undmthe auhpim of the UMHHI)A.

i/damesIe laboratory

of tho Univw9ity of Galifornla

An Allirmativa Ac?ion/Equol Oppertunilv Employeei“.

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High-Premmre Tri:iun

Don O. Coffin

Los Alanos Scientific Laboratory, University of California

P. O. Box 1663, Mail Stop 980, Los Almos, Sex Mexico 87545

11 pagen

4 figures

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High-Pressure Tritium

non o, coffinLos Alamoe Scientific Mborntory, University of California

Los Alamos, New Mexico

Abmtract

Some solutions to problems of compressing and cuntainin~ trltlum

gas to 200 MPa at 700 K are discussed. The principal eaphasis i~ on

commercial compressors and high-pressure equipment thn~ can be ameily

modified by the researcher for a=fe use with tritium, Experfmicc with

metal bellows and diaphragm compreasora has been favwablc. Selcctlon

of materials, fittings, and gauges for high-prmmmrc tritlum wrk is

also reviewed briefly.

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nnd infrequent maintenance is the mo~t important factor in reducing

personnel exposures.

GAUGES

Gauging In a particularly demanding problca becau~e tritium la a

controlled radioactive wterial, and its accountability at high prescurc

i- best done by accurate pressure-volume-temperature mtmsurements. Gfmgcs

that operate by deflection of an elarntlc wmber necessarily Incorporate

●mallcr safety factors than duslrccl for conservati~’e design. tlcverthe-

lea~9Bourdon-tube gauaes huvc served the prewure indu~try for inure than

a ccnLury. and nre u good cholcc for tritjum if th~ Bourdon material im

hydrooan-compat ible. ?fany ~nufacturer~ furnitih Eburdon guu~es in

austcnitic Otainlcsn mtccl~ or Iwrylllum cupper fn a wldc rangu of

pressurc~. The nddiclon of fnrcr-balancing nnd digltal””rrxlwt tech-

niques hJB greutly cnhmcml the preclnlon of tlwse inherently Rlmple

dcviccs. Strain-gauge transdu~ern are preferred by many cxpcrlmcntcrn

now. Solld-titatc dlgltal elcctronic~ and improvec quall~y control hnvo

resulted in prccisluns rivaling tho~e of the force-balm IJourdon-tube

systca$. A1l-uel.dcd trunsducors of trlttum-coiopnt lblc rn~crinl~ nr(q

n190 avnilablc from sev~~ral manufacturers.

COMPRESSORS

The principal cons~ralnts on trltlum pumps. cnumurutcd hy Fulkcr~

and Cedco4 ar~” that they Incorporutc no movln~ ~haft I+cal~, clnHLowr,!,

or orgnnlr fluldn. Comprcwl)r~ which cnn rcndily inwt thwc rl’quirc~nt~

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Classification (c) compri~c~ conpremms which c-ploy metal bellows

o: diaphragms, Several wnufticturrrs ❑aku dlnphragm cmprunsors6Bo~g

and ~hc brst m.udels in: tritium iucorpor~tc a ~tainlcsn ~tccl dlaphrag-

welded to the gas head. Since rc11a510 WOICIS arc dlf[lcult to mnke for

service above 100 ?lW, we are usin~ ~1 hydraulically londcd Meal of gold

plating on the gas diaphragm At 1~~ Wa no trltlum Irnkngc cm be

detected vit!l the usual portable air zonitor, and diaphra~m life in

mlmost iniinite if tho gas ig free of parttculntus. The utilization of

triple diapl~raym S (isg= 3) with mI appropria~c vunt port can slvc cffcc-

tivu secondary containment for thr nu;t llkcly mdc of compressor faflurc.

At this Laboratory we have urmd a mul:istn~c dhphrarp pump routinely

to coaprc~s tritfu2 to 1.’IOWa. The only continuing wlntunnncc has lmcn

frequ~nt (’han~~s of lntC!r!lt~~L! chc~”k ‘;IIvc’s, whlrh originally had flul)ro-

carbon fact! seals and cI~stornt’r poppnrs. These mntoriuls havv now hem

repla~.~’d with i101:;i2idU$J, nnd some of Lhctw vJlvcM urr still opcrntin~

●.211 ~fter Cw:j v,,.,r.+ .s[ IntcrmiLtcnt trlLiUM Murvi~c.

!4etal-bcllnxs conprcswr~ 10 h=~~ ~om,s on thu market in the past f-

year~, A design lini:atlon of the stfindilrd comprcswor for Lritlum IR

exceti~ivc usu ~f fluorrwarbon Plilstlc in the check-valve hmdcr. We

have rcpla:ed this with an all-metal valve nmembly, and r~.c manufacturct

will provide un ali-welded assembly at conisidernhlc extra co~t, Because

tha mechanically driven helluwn i~ unsupported, the output preRnurc iti

limltcd to about 0.5 WV. The only intcrc~t in thin pump for the high-

prcs~uru cxpcrinaentcr, tlmre[orc, 13 as a tran~fcr pump or first ●tago

of a multistdgc HyHtcrn.

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At thi~ Laboratory a balanced-pressure, hydraulically driven, metal-

belloxq coaprus%or has been built (Fig. 4). lt is designed to give a

50/1 cumprusslon aatiu nt 2C0 UPa diuchargc. Coupled to a suitable out-

put volum, it can provide very sensitive

hydraulic proportioning pump; driven by a

pump, it is capwble of onc 25&cm3 stroke

C~CLCSI~

presaurc control by uae of a

conventional hydraulic plunger

pcr minute,

Although several manufacturers make compresaora and hardware that

can bo modified for tritium uac. no current it-m of off-the-shelf equip-

ment la completely aatiafactory. For example, every diaphragm-pump supplier

UIJQS mm fluorocarbon or elastomer

COU~d be avnidcd. Tritlum usQrH in

infor~i industry on the requirements

tritiwn Is merging as a vital fuel

in the compressor even though these

the fusion-energy program must fully

for tritium handling. Now that

for the world’s future energy needs,

wc can and must aprly the best current technology to ita safe handling

and containmmt,

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1. J. F, Lakncr, “PruposcJ Prcwwru vrHs._l c, IncLI~:, ..tt., ,” ~lwrc~n.,~.

Livermorc Laboratory Report UCID-16833 (1!?75),

2. E. I. du Pent de :umour~ & Cuupan} (Inc. ) Pl:,s: ics 1}.”p:.,

Wilmington, DE 19S98.

3. Fluid Conpon~::t~ Division, Ikltrul Corp., Gr:ulL & XI:!I Ave.,

Bcllwood, IL 60104.

4. C. L. Folkers and Y. P. Cede, Prnc. .?3ril Conf. !kaoLe !iyst,

Teclmol., 55 (1975).

5. F. J. Edeskuty, lnd. Eng. Chcm. 51, 69 (1959).

6. American Instrument Co., Silver Spring, MI 22910.

7. D. H. Carstcns, Proc. 23rd Couf. lkmd~u Syst. I=r<n:.;., 69 (1975).

8. Preesure Products Tndutitrius. 9Wl Louis lW., !:.,rnil~+:.”r, PA 1B974.

9. Autoclave Engineersp 2930 H, 22nd St., Erie, i’A 16;12.

10. Metal Ilel.lous Co., 1075 Providence Hlglrsay, ~kti:~n, Y! 02067.

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:

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‘- secondary

Piston

High PressureA/olve

\J/JD. O. Col?fln“tligh-Pr@M3ure Trltium”

Fig. 1

1- Gas out

Hydrauhcin

II

+

———.

—.-

—. ‘K/

D. 0. Coffia“lliEh-Presaura Tritlum”

Fig. 2

To . WeldDumpTank r rGas Head

LOil Head

(3)

&..

LHydraulic In

I[1--- Position

1Indicator

Il.O. Coffin“l[l~h-Pru~HtlrcTrltlum”

Fig. 4