ORNL/RSIC--55 DE93 003288 Engineering Physics and Mathematics Division EARLY TEST FACILITIES ANDANALYTIC METHODS FOR RADIATION SHIELDING Proceedings of a Special Session for the Radiation Protection and Shielding Division at the ,Mnerican Nuclear Society Winter Meeting Chicago, Illinois, November 15-20, 1992 " Compiled by: D. T. Ingersoll " Oak Ridge National Laboratory and J. K. Ingersoll Tec-Com, Inc. Published: November 1992 . Prepared by the OAK RIDGE NATIONAL LABORATORY Oak Ridge, Tennessee 37831 - managed by MARTIN MARIETI'A ENERGY SYSTEMS, INC. for the under contract DE-AC05-840R21400 U.S. DEPARTMENT OF ENERGY M__TER _ Preface This report represents a compilationof eight paperspresentedat the 1992 AmericanNuclear , Society/EuropeanNuclearSociety InternationalMeetingheld in Chicago,IllinoisonNovember 15- 20, 1992. Themeeting is of special significancesince it commemoratesthe50th anniversaryof the firstcontrollednuclear chain reaction,which occurred,not coincidentally,in Chicago.The papers containedin thisreportwerepresentedinaspecial session organizedbytheRadiationProtectionand ShieldingDivision in keeping withthehistoricaltheme of themeeting. I must admitthat throughoutmy school years,history was one of my least favorite subjects, owing in partto its seeminglack of relevance. Suchis not thecase here. As headof thepresent-day shieldingsectionat ORNL,Ifeel aclose professionalaffiliationwithandapersonalsenseof gratitude towardthe _:athorJandthe people whom they describe ixttheir papers. They areindividuals who helpedto fo_ _e foundationsof thedisciplineof radiationshieldingandhavealibeenappropriately honoredbywidespreadrecognitionfortheiraccomplishments.Intheirpapers,they presenta collage of facts andpersonal remembrances,which I find delightfully entertaining, fascinatingand even inspiring.The picture presentedhereis byno means complete;many other talentedand dedicated individuals havecontributedto the historyof radiationshielding.However,meetingtimewaslimited and tough decisions had to be made. Thefirpapst erau, thorebdyLorraineAbbott,coulhad ,:eopenedwith:"inthebeginning..."She describestheearliest activities in radiationshielding research,whichbegan inunediately following the Chicagopiletest.Frontieringprogramsgrewfromthe insight andeffortsof threekey individuals: EverittBlizard,Theodore Rockwell, and CharlesClifford.Abbott goes on to describe the major influence th_ Adm. Hyman Rickover had over those early programs and directions. The first shielding expe_ments attheOakRidge X-10Pilewere in supportof the Hanfordproductionreactors, which later spawn_ shielding researchat that site, as describedby Wilbur Bunch in the second • paper.Bunch provides a thorough description of their development and testing program, which focused primarilyon iron/masonite'_elds aJ:,_al vast range of special concretes.In aninteresting aside,Bunchnotesthatnoteverythiiigfromthose dayssurvived,suchas the "vigor" unit,whichnever gainedthe samelevel of acceptanceas did therelated"lethargy" unit. Thethirdpaper,writtenbyNorm Schaefer,describesa fascinatingtestprogramfortheAircraft Nuclear PropulsionProject.Theuniquechallengeof these testsis bestreflectedin the factthatnuclear engineers participatingin the test hadto firstbe trainedin parachutejumping.Thelimitations of the groundtests _ndthe awkwardnessof the flight tests led to a compromise solution: experiments conductedat the Oak Ridge Tower Shielding Facility, which allowed the reactorand shield to be suspended200 ft above the ground.The design,constructionandoperation of the TSF is described in the fourthpaper,authoredby Buzz Muckenthaler. The TSF,whichmustbe the longest surviving shield test facility, has supportedavast arrayof na_onal programs,many of which arehighlighted in Muckenthaler'spaper. Switching from early shield test facilities to early shielding design methods, Dave Trubey describesin the fifth papertheoriginaldevelopmentand evolution of buildupfactors. Point-kernel " codes employingbuildupfactors were someof the first successful computationalmethods andare stillin frequentuse today.The methodexemplifiesthe artisticnatureofshieldingdesign analysisdue to the needtoconstantlybalancespeedandaccuracy,aproblemwhichpersistseven today.Inthe sixth . paper, Kal Shure describes the early methods used at Bettis Laboratoryfor the Naval Reactor program.Cloaked by secrecy, many of the developments at Bettis paralleled work at other laboratories.Shurewittily placesin perspectivethe "worthiness" of resultscomputedwith these early codes, and makes reference to "user-tolerable"codesm a termwhich unfortunatelyappliesto even modem computingsoftware. 111 The seventh paper, authored by John Butler, provides a thoughtful description of radiation shielding research as it began in the United Kingdom. With a primary focus on kemel and Monte. Carlo methods, much of the U.K. development complemented U.S, activities. The same was true of benchmark tes_tg activities in the U.K., which centered around the LIDO facility and later the NESTOR/ASPIS facility. In the eighth and final paper, Herb Goldstein begins by stating that: "The title tells it all." In classic Goldstein style, he presents a wise and delightfully personal review of early computation methods, nuclear data, and even the early computers. He does well to point out the project-driven nature of shielding development, but goes on to describe some of those rare nuggets of fundamental theoretical research which have managed to "trickle" along the way. Goldstein provides a fitting conclusion to the session by stating that: "Now we have the tools...if anyone still wants to ask the questions, and is willing to pay for the answers." Unlike most meeting proceeAings, which are meant to be studied one paper at a time, this collection of historical perspectives is meant to be taken as a whole and is best suited for a quiet evening and a soft armchair. So get comfortable and enjoy. Dan btgersoll Nuclear Analysis & Shielding Section Oak Ridge National Laboratory iv Table of Contents Preface...................................................................................................................................... iii Acknowledgements .................................................................................................................. vii Biographies .............................................................................................................................. ix The Origin of Radiation Shielding Research: The Oak Ridge Perspective Lorraine S. Abbott .............................................................................................................. 1 Shielding Research at the Hanford Site Wilbur L. Bunch ................................................................................................................. 9 Aircraft Shielding Experiments at General Dynamics Fort Worth, 1950-1962 Norman M. Schaeffer ....................................................................................................... 17 Where Have the Neutrons Gone--A History of the Tower Shielding Facility F. J. Muckenthaler ............................... :........................................................................... 33 History and Evolution of Buildup Factors David K. Trubey ............................................................................................................... 47 . Early Shielding Research at Bettis Atomic P_wer Laboratory Kalman Shure and 0. J. Wallace ...................................................................................... 55 . UK ReactorShielding:Then and Now John Butler ....................................................................................................................... 59 A Very PersonalView of the Developmentof RadiationShielding Theory Herbert Goldstein ............................................................................................................. 75 Acknowledgements We wish to especially thank the authors for meeting the tight schedule for completing their manuscripts. Since it was desired to distribute the proceedings at the session, the authors had to " prepare their papers well in advance of the meeting. We also wish to thank Dave Trubey, who helped with the organization of the special session, and John Butler, who served as co-chairman. We are grateful to Lorraine Abbott forvolunteering the services of herprivate company forthe collection and preparation of the final manuscripts, and to Bob Roussin, director of the Radiation Shielding Information Center, for his willingness to pay for reproduction costs. Finally, we recognize the support of the ANS Radiation Protection and Shielding Division, and especially the RP&S Program Committee for their assistance in supporting this special session. vii Biographies Brief biographical sketches foreach of the authorsaregiven below in the orderin which their - papersarepresented.With sucha distinguishedgroupof individuals,it wasimpracticalto list aliof their accomplishmentsandawards.Suffice it to say thatthey have allbeen widely recognized and honored. Also, not surprisingly,theyhave alib_enformally acknowledgedbyANS fortheir technical excellence and distinguished service to the society. Lorraine S. Abbott received a B.S. degree in chemistry from Maryville College in 1948. She combined her technical degree and her interest in journalism to become a technical editor and writerat Oak Ridge National Laboratory,specialh:ing in recording radiationshielding research from 1948 to 1986. Of the numerous &xaunents