Document pBgjyXVXNzV6DLrdG5KOMBJod

LI A24205 o - LEAD INDUSTRIES ASSOCIATION, INC. 291 MADISON AVINUK NtW YORK, N. Y. 10017 flllFHONl - ANCA COOS til ON MOM Soptecbr 1, 1964 SUBJECT; LEAD ZrRCOKVTE71?MiATE To Kecbers of the Lesd Industries Aaaocistion, Inc: The attached reprint of an article that appeared recently in American Machinist cagazine is highly favorable to a relatively * new leal product - lead zirconate-tltanate - the use of which is growing rapidly in cocpctitlon with other piezoelectric tutorials because of its superior perforaance. Hleaso note in particular the statement in the last paragraph of the first column of the second page. We estimate that this new material currently accounts for the consumption of between 500 and 1,000 tons of metallic lead annually and several additional companies havo recently Joined the list of its producers. L.X.A. will use these reprints as an aid in answering inquiries on the eubject. Members ray obtain additional copies from us free in quantities up to 25 and at our cost of 2.5f per copy in larger quantities as long as our limited supply lasts. Very truly yours, RLZ:so Enc. -TVS Executive Vice President o pol I LIA2A206 tI o Cleaning radioactive parts Growing use of radioisotopes by industry--for inspection or measuring wear, for example--is creating a new problem: How do you get rid of the radiation when it has served its purpose? Ultrasonic cleaning is one solution T>.* increasing use of radioactive every precaution Is taken to pre ixjtcrjx** by jrduilry and by re vent contamination n/ tools, parts, search laboratories has led to a and other eli-mcnts near the source widespread interest in ways and of radiation. means of insuring that part* rx* Radioactive device* arc usually posed to such radiation can be well aralcd. but leakage u nut an completely decontaminated, impossibility. Any part that be On a somewhat different tacV, comes contaminated is a hazard to low.level radiation U being used human life and health and thus to check the efficiency of cleaning requires an efTvetive means of re techniques used for air filters moving the contamination. and instrument components. These Human beings can, tn general, be components, which mu.-t be clean expo*-cd without danger to radi beyond the capabilities of mo>t ation in amounts up to five roent conventional equipment, are given gens per year. Average dose m or ----- ----------- --- __ Ji-- - a dose of radiation before cleaning: dinary surroundings (background * then, if the cleaning technique re level of radiation to which people SO^watt ultrasoAii cleaning unit Q moves the radiation, the compo nents muet be ``cleaner than clean.** Decontamination t* a must are exposed da:ly) vane* with geo graphic area*. In Southern Cali fornia, for example, tht* *ce! is 0 05 rorr.tgfha per year; in Den removes rCuton ,'eo Cpfy recessed part* or threaded component* means of removing i ado.active par The hazards of radiation arc well ver it is 0 t. ticles from contain!*.ated purls. known, and in ail industrial appli- Parts that have N-en exposed to The key to this is the tremendous rations-part wear determinations, excr^'ive radioactivity must, there force of cavitation with.n a liquid rudiogr-phy, me^-urmtc-nl of fore, be detvnta?Rirati-d to at least rrn-dium. grinding wheel wear, and thickness their particular background level. Since sound travels through all measurement, to name a few- Generally, then, it is nrec^ary to media in wave* of comprevsn-n and know what the background level rarifaction. sound waves releax-d 15 before cleaning the parts. This under great power in a liquid will Sr Donald L Collin* simply involves taking a dosimeter form small bubble* in the ranged President reading in the area. portion of a wave. When the com The landivtrk Electrometer Co L'ltra'-omc cleaning has been pression portion of the wave pars dendaie. Cald found to be the most practical es, these bubbles arc comprc<*ed to r~ -1 System for decontaminating radioactive part* and checking the effecbveneu of decontamination ton,ts of a Landsverk L 8bOA ultrasonic cleaning unit and a radiation detector Reorinted from American Machinist. jw>r MM c IHI I. tic Vi4 2n* St. Nw T<k, H. V N 2015.01 L1A24207 -I the point wlu*.v they implode, tli.it high-C). tow-impedance land'V* ; k Choice o! ensuing solution and i.i, they burst in a* irds. Thu cavitation effect* tremen dous pressures and temperatures tran.Jueer, pu .oelivtrtc er> l d capable of W ithslandmg temper atures to 300 K are saiulwiehed be- Mdvcnt u important if the cunt.umrianl is to be thoroughly re moved In r*>-.t c.ix-s, water and o PPh Iu h i! m the area* when? twiin two metal suifjees so tlut Oakite Jl lake care of rudioic- these bubbles are imploding -liter a tneldl-to-metal l>ond is achieved tive pi.it.iU r.Tirjently, Trace ally blast* micro>fop*c particle* of ltw<cn the inUifacr of tin* trans amounts of raJ.o.telivity arc usu- dirt and other fnieign matter from ducer and the radiating surface of ally drained away with the used otherwise* inaccessible recesses Ill the stainless steel cleaning tank. solution in a normal manner, but the pads being cleaned. A relatively low (rcqueitc/ of solutions containing hazardous Greater pewer required 25 kc provides a vigorous i leaning amounts of radioactivity ore dis action yet is high enough to be out pos'd of in accordance with law. Out decontamination of radioac of the audible range. In many low- Threaded parts or parts with re tive parti requires greater cleanli* fuquency ultrasonic cleaning op cesses can be effectively cleaned new, and this demands greater erations, standing waves, which are with this technique. After such power and more uniform distribu piuiuccd at each half-w*ave1ength parts are cleaned a wip lot Is usu tion of it than is normal for ultra- within the liquid medium, roull ally made with a scintillation coun sonieully cleaning ordinary parti. in "dead spots'* where little or no ter to gel an immediate reading For example, Landsvt-rk found cleaning action occurs. of any residual radiation. that 850 watts were required to decontaminate lead bricks (used This can be overcome in con ventional systems by moving the Radiation checks cleaning as shielding tn a 5pcei.il radiation work up and down in tlie liquid. A *wYch ub-av.wmbly, made up application) to the background The new system does away with of a small bellows w ith a glass-to- level. Uccausc ordinary ultrasonic this; it provides a slight frequency melal m-u I ana a flange soldered cleaning m tup* provide only 100 sweep that allows an overlapping together. ma* found to be accumu to 200 watts and operate at about of the standing waxes. As a re lating dirt and flux frem handling 50'. clTiciency, it was necessary to sult, the cleaning power is evenly and soldering. Trace amounts of design a special system. distributed, there are no dead radioactive material were added to Efficiency of this special 850- spots, and there Is no need for these contaminants, and after as * watt system is 85';. mainly be agitating the work. sembly was completed the degree cause of a lead-nrconate sandwich Automatic tuning adjusts the of residual radioactivity was mcas- transducer that is more reliable generator frequency to compensate ured with a scintillation counter. than the usual piezoelectric trans for changes in tank load or liquid Ordinary ultrasonic cleaning was ducer and more v'fieient than the level, liquid temperature, or type ineffective, but the new 8SC-watt magnc!otnrtivc type. In the of h.(Uid Ux.*d. unit removed all radiation. ! fVrilNitid by: 1*44 Industries AMocishM, fsc -mrl Mwt Avrtifir NVx Y*ak, \V Y*rfc |U>|7 \ rs..*-a,r \ o