Presented before the Division 01 Chemical Educrtlon at the 113th Meet ing of the American Chemical Society

Introductory Remarks J. A . S WARTOUT

Oak Ridge National Laboratory, Oak Ridge, Ten’,,.

prior to the advent of the uranium pile nearly all radio- chemical researoh was conducted in standard chemical laboratories. The small amounts of radioisotopes from natural s o m or high energy accelerators constituted minor radiation hazards. In wntraet, the uranium pile made possible the production of the relatively large amounts of radioisotopes which are now being distributed to -h institutions. Because of the urgency of the s r c h p-m for the production of 6ssionahle mate- ripl it was necessary during the war to utilize existing Inboratories or temporary structures. Modification of these facilities was r-rted to as high intensity sources

ITHtheadvent of theuraniumreactorand the subsequent w distnbutlon ” from Oak Ridge of radioisatopes produced in this reactor, the extent of radiochemical researoh and the number of institutions engaged in it have greatly increased. A logical consequence of this growing emphasis is a more general coucern about optimum methods for handling radioactive materials and the types of lahorntorim in which such chemical work may be satisfactorily conducted. An eqnal, if not greater, reason for this intereat in the design pf laboratories specifically suited for radio- chemical researoh is the pronounced increase in the amount of radioisotopes which have thus been made available. In contrast with the microcurie quantities obtainable from the cyclotron, which was the primary source of artificial radioisotopes prior to the war, as much as several hundred millicuries are contained in individual shipments now leaving Oak Ridge. Within the laboratories of the Atomic Energy Commission the differential is amplified further in that chemical research is frequently per- formed with many curies of radioiaotopes. Nearly all radiochemical research, with the exception of that

with relatively high levels of radiation in a few special laboratories of the Atomic Energy Cornmiasion, has been performed up to the present time in standard chemical laboratories. The chemical laboratories of the various installations under the Atomic Energy Commission are, in general, of temporary, wartime construction patterned after prewar university and industrial laboratories. During the war a few laboratories with provisions far accommo- dating moderate and high levels of radiation were constructed at the Metallurgical Laboratory of the University of Chicago (now Argonne National Laboratory), Clinton Laboratories (now OaL Ridge National Laboratory), and Los Alamos Scientific Lab- oratory. In general, thee early versions of “hot” laboratories whom design w88 neoesSarily based on relatively little experience have become inadequate and outmoded.

became available for research. The research centers of the Atomic Energy Commission are now undertaking pm- grams for replacing the temporary chemieal laboratories with permanent laboratories designed specifically for radiochemical work. In addition, other institutions en- gaged in researoh with radioisotopes distributed from Oak Ridge are b m i n g concerned with the design of such laboratories. Because few radiochemical lahoratoriea have yet heen constructed, current designs and concepts are, in many cases, preliminary and untested. In general. they are based upon extensive and varied radioehemical research with a wide range of levels of radioaetivitg.

The laboratories of the Atomic Energy Commission are nou in various stages of replacing the unsatisfactory and temporary StNCtureS with permanent laboratories designed specifically for chemical research with various lev& of radioactivity. Included among these are Argonne National Laboratory, which has com- menced construction on a new site west of Chicago; Brookhaveil National Laboratory, for which permanent replacements for thp temporary laboratories modified from the army buildings of former Camp Upton are being designed; Hanford Works oper- ated by the General Electric Company where new research lab- oratories me planned; the Institute of Atomic Research at Iowa State College, also constructing a metallurgical and chemical laboratory; the Knolls Atomic Power Laboratory of the Gen- eral Electric Company now under construction; .Lo8 Alamos Scientific Laboratory; the Marion and Miamisburg, Ohio, lahora- torim operated by the Monsanto khemical Company; Oak Ridge National Laboratory, which will replace its extensive temporary buildings with permanent structures on the same Site; and the Radhtion Laboratory, University ol California, which has com- pleted new laboratories for moderately hot research. In addition, similar building program are under way at the Naval Radiation Laboratory in Ssn Francisco and the Institute lor Nuclear Studies of the University of Chicago.

Because many of these in themelves are major construction projects, the composite of this program for the construction of facilities for nuclear research represents a tremendous expendi- ture. Coordination of the design work of the various Atomic Energy Commission sites has been achieved to a considerable extent by regularly scheduled information meetiugs held at Ar- gonne, Brookhaven, and Oak Ridge National Labaratoriea over the past year. Despite this, differences exist between concepts of what constitutes ideal radiochemical laboratories. In part these variations arise from diEerencea between the general types

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228 I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y ' Vol. 41, NO. 2

of research emphasized at the individual locations, in part from the lack of opportunity to date to prove the validity of some de- sign details, and finally from the inherent differences in the man- ner in which any two individuals might accomplish the same task.

UNIVERSITY AND INDUSTRIAL LABORATORIES

Although the scale of construction planncd by the Atomic Energy Commission is necessarily large because of its primary emphasis on nuclear research, the greater interest, numerically a t least, probably is in the const,ruction or remodeling of labora- tories on a more modest scale. University and industrial lab- oratories in which the emphasis is more diversified or which use radiochemical techniques merely as a research tool are concerned with, at most, a few laboratory units usually for tracer research. The problems of designing such units and of remodeling existing laboratories are considered in separate papers in thi5 symposium.

GENERAL FACTORS

Because of the wide range between the levels of radiation from the microcurie to the multicurie scale involved in current re- search problems, the variety of radioisotopes which are being used in chemical research, and the differences between the types and intensities of the radiation emitted by these isotopes, the problem of designing working spaces in which research may bp carried out efficiently and safely necessarily has no single solu- tion. These factors may be subdivided on the basis of the haz- ards attendant on chemical operations with each. This analysis, in turn, permits consideration of the design features and manipu- lative methods requisite or desirable for the corresponding sub- division.

RECEIVSD 3Iay 10, 1948. Based on work performed undev Contract W-35-058-eng-71 for the Atomic Energy Proieot a t Oak Ridge National Laboratory.

Impact o f Radioactivity on Chemical laboratory Techniques and Design

PAUL C. TO3IPKINS AND HENRI A. LEVY Oak Ridge iVutional Laboratory, Oak Ridge, Tenn.

T h e radiative properties of radioactive substances are independent of their chemical properties and impose addi- tional requirements on chemical laboratory design and practice. A general philosophy is developed through which problems associated with the handling of radio- active materials may be successfully attacked. A n at- tempt is made to establish a basis on which to build satis- factory standards of practice, and to evaluate the result- ing impact on the facilities for implementing them. In particular, the segregation of areas of work, and types of facility appropriate to each, are discussed. Problems of ventilation, accumulation of activity, and material control are examined in the light of these considerations. The selection of laboratory furniture, surface materials, floors, and shielding is discussed.

111s paper discusses features of chemical laboratories and T laboratory practice peculiarly ielated to the full and safe use of radioaktive materials. Present design and technique are tailored to the chemical properties of materials of investigation. Design and technique for radiochemical laboratories should be compatible as Fell with radiative properties; these, being essen- tially nuclear, are independent of chemical properties and impose additional variable requirements in laboratory practice.

The requirements imposed by radioactivity are discussed rela- tive to two major parameters: radioactive contamination and pcnetrating radiation. The objective of technique and design is the execution of operations, which are chiefly prescribed by chemical considerations, n7ithout jeopardy to personnel, experi- ments, or products from undesired effects of radioactivity. In choosing a manipulation for carrying out a chemical operation- for example, the separation of a solid from a liquid phase-fil- tration by gravity or suction, or centrifugation, is no longer a matter of convenience or purely chemical effectiveness; the choice is one in which the radioactive parameters, contamination and radiation, often play a determining part. In the absence of radioactivity, the wide variety of manipulative problems en- compassing the practice of chemistry is reflected in different kinds

of laboratories-for example, those for microchemistry, control analysis, physical chemistry, or general experimental chemistry. The impact of radioactivity on each will be different, but in all cases it will depend on the magnitude of the contamination and radiative levels.

COhTbR.I~NA'ITON PARAMETER

By radioactive contamination is meant the unwanted migra- tion of radioactivity into places where it may harm persons (on skin or in lungs), experiments (into reagents or analytical sam- ples), or products. The prevention of serious contamination is really a problem of matcrial control, as radioactivity is always associated with matter. It differs from more usual problems of material control in that the amounts of material involved may range down to small fractions of a microgram. In discussing the problem of contamination it is uaeful to define several concepts.

The critical quantity, q, is defined as that mass or volume of material containing an amount of radioactivity, a, which may bo objectionable in a given situation. For example, for hard bets- contamination on an open table top, a is taken from health con- siderations as 0.001 microcurie per square foot. Thus, for a solu- tion containing 0.01 pc. in 10 ml., q is 1 ml., with which there is no difficulty of control; in contrast, for a solution containing 1 mc. in 10 ml., q is 10-6 ml., a volume which can easily bc lost during chemical operations and whose control may be difficult. For solid materials, uranium is analogous to the first example, radium to the second. The complement of the percentage of the total activity which constitutes a is defined to be the re uired degree of control: Thus in the second example a is 1 0 - 4 % of the total (1 me.) and the required control is thereforc 99.9999~&

Chemical operations can rarely be expected to meet such strin- If this is the case, there pxisls a gent control requirements.

contamination potential:

This term the authors define as the ratio of the quantity of material which may be lost in a given operation performed by a given technique to the critical quantity, q. Thus in the second example quoted above, if a pipetting is made by ordinary methods, for which loss of 0.01 ml. is easily possible, the contamination po- tential of the operation is 0.01/10--6 = 1000. A value of the con-