INTERNATIONAL ACCELERATOR RADIOLOGICAL PROTECTION E-MAIL (IARPE) NEWSLETTER "The Official Publication of the Accelerator Section of the Health Physics Society" (with Contributions from International Correspondents) ------------------------------------------------------------------------ March/April 1998 Circulation: 200 Vol.7, #2 ------------------------------------------------------------------------ OFFICERS President: Vashek Vylet, SLAC President-Elect: Steve Musolino, BNL Past President: Lutz Moritz, TRIUMF Secretary: Scott Walker, LANL Treasurer: Gerry Fallon, MIT Newsletter Editor:Scott Schwahn, Jefferson Lab Directors: Jeff Leavey, IBM (1998) Tracy Tipping, KSU (1998) Wes M. Dunn, International Isotopes (1999) Henry Kahnhauser, BNL (1999) Bob May, Jefferson Lab (2000) Keith Welch, Jefferson Lab (2000) CONTENTS From the Editor From the President Response from Ralph Thomas News from correspondents: AGS CAMD CERN Fermilab Jefferson Lab RHIC Other News: First Announcement, ICRS-9 Memoriam How to subscribe or update subscription ------------------------------------------------------------------------ From the Editor Scott Schwahn ------------------------------------------------------------------------ We are quickly approaching the time for the annual meeting. As such, we are also quickly approaching voting time for new officers. Some details on the process may be found in the President's Report. I am pleased to present a reply from Ralph Thomas about last month's questions posed by Manfred Hoefert, updates from six institutions and a first announcement for The Ninth International Conference on Radiation Shielding. If you are an Accelerator Section member, please be an active participant in the voting process. Ballots will go out soon, so keep an eye on your e-mail. ------------------------------------------------------------------------ Words from the President Vashek Vylet ------------------------------------------------------------------------ As you learned in the last IARPE issue, this will be the first year when you can elect Accelerator Section officers from the comfort of your (office or home) chair. After the new amendment to Section Bylaws was approved by the HPS Board of Directors at the midyear meeting last February, the Nominating Committee carefully considered its implications. The Bylaws now allow both to cast your vote by correspondence before the meeting, or to vote at the annual HPS meeting in person. It was feared, however, that mixing both types of votes would be cumbersome: verifying who already voted and who can vote at the Section meeting could consume much of the allotted time. The Section Board of Directors, after discussing this issue by e-mail, approved the request of the Nominating Committee to elect Section officers by correspondence only. The charter of the Nominating Committee has been broadened to "Nominating and Election Committee", since they will be processing your votes. By the time you read this, you may receive from Ralph Thomas the list of candidates and other details. I sincerely hope that you will find this new method convenient and that member participation in the elections will drastically increase. ------------------------------------------------------------------------ Reply to Hoefert Ralph Thomas ------------------------------------------------------------------------ Dear Editor, Answer to Hoefert: "IARPE Newsletter - Jan/Feb 1998" In the Newsletter (Editor's note: please see Jan/Feb 1998 CERN contribution) Dr. Hoefert asks the question: "Should we believe the statement of Dr. R. Bertell, International Institute of Concern for Public Health, Toronto, Canada, that the original ICRP dose limit of 5 rem per year for workers was forwarded before the first dose effect estimations for the victims from Hiroshima and Nagasaki had even been made?" The answer to his question is assuredly "yes". The change from 15 rem to 5 rem in the annual whole body radiation-protection-limit to workers, promulgated by ICRP in 1956 was based on genetic and political considerations. ICRP has never publicly admitted that political considerations played any part in its decision but, remember, these were the days of Linus Pauling and widespread public concern over the health effects that might result from the atmospheric testing of nuclear weapons. In the years after 1956, as more data became available, the concerns over genetic effects diminished to be replaced by concerns over the induction of cancers. The maintenance of the whole body limit at 5 Rem per year during the time when scientific data on cancer induction were being accumulated appears to be fortuitous and based on considerations other than science. I quote from a lecture I gave at the Medical School of Stanford University in January 1970(1): "Genetic considerations became of increasing relevance as the results of exposure of large populations to small doses of radiation were studied. Taylor(2) reports that as early as 1933 Failla foresaw the importance of the work of Mueller this general area. By the late forties several geneticists were working with the NCRP and Charles, Mueller and Stern played an important role in the formulation of NCRP policy. There was an important realization that for genetic effects 'there might be an element of risk in the use of radiation and that, however small, the element of risk could never completely disappear.' "Several independent studies were made in the mid-fifties, by the (US) National Academy of Sciences, NCRP, ICRP, the Medical Research Council (UK) and the United Nations, of the problems posed by occupational and population exposure. Thus by the mid-fifties, when public concern on the effects of ionizing radiations was stimulated by fall out from nuclear weapons testing the technical questions which arose had been considered and action which was apparently taken in reaction to public concern was in fact largely anticipated." Lauriston Taylor has described the situation thus: "As I have noted, one of the major influences on the formulation of protection philosophy developed in the mid 1950's following heavy fallout from nuclear weapons tests. The impact was felt in many phases of the radiation protection problem and the pressures that developed have compelled the introduction of restrictions many of which are felt to be unwise or unduly restrictive. "Considerable play on the subject by the daily press developed an element of alarm among the population. Sensational writers produced a flood of distorted stories about the hazards of radiation. While these were built around certain established facts, many of the stories either neglected or played down the favorable aspects of the problem and accented only those of an alarming nature. "Pressures on the general public by 'recognized scientific groups,' and an assortment of individuals, developed at an alarming rate. In principle, the public discussion was not necessarily bad, but actually very few of the groups have had the full facts at hand." La plus ca change? Ralph H. Thomas Moraga California References (1) Thomas, R. H "History of Radiation Protection Standards", Stanford Workshops on Political Issues, 20 January 1970. RHT/Technical Note/70-3 (unpublished). (2)Taylor, L. S. "Philosophical Influences in Radiation protection Standards" Health Physics 11, 859 (1995). ------------------------------------------------------------------------ News from AGS Chuck Schaefer ------------------------------------------------------------------------ During the last 12 months I chaired an Accelerator Readiness Review (ARR) Team tasked with verifying the readiness of equipment, personnel and training for a compact 10 MeV electron accelerator housed in the Chemistry department. By following DOE 5480.25, Safety of Accelerator Facilities, we we finally able to secure DOE's permission for routine operations in late March. The machine is capable of delivering extremely short pulses of electrons for use in radiation chemistry research. Pulse widths of 5 picoseconds are possible. The machine produces these pulses by laser light impinging on a magnesium photocathode inside a resonant cavity RF gun about 30 cm long. The electrons are accelerated by 15 MW of peak RF power from a SLAC-type S-band klystron. The facility will be used for pulse radiolysis, a branch of chemistry research which uses short bursts of x rays or electrons to generate free electrons and other short-lived molecular fragments within aqueous samples. Picosecond pulses make possible the study of very fast chemical reaction rates. Fault studies showed no measureable dose rates in the adjacent control room. Both the control room and laser room are shielded by concrete. The klystron produced some measureable x-ray dose rates within several feet of the unit. The maximum electron energy of 10 MeV was chosen specifically so that activation of beam-line components by photoneutrons would not be a concern. The threshold for the production of neutrons by gamma-bombardment of nitrogen is 10.55 MeV, and 15.67 MeV for oxygen. The accelerator safety envelope includes a maximum integrated beam current of 220 nanoamperes for eight hours. Typical operating conditions are 20 nc/pulse at 10 hertz for an average beam current of 0.2 microamperes. Maximum dose rates measured near the target stations were approximately 0.5 Sv/h (50 rem/hr). Doors to the target room are interlocked with the electron beam such that inadvertent entry causes the interlock system to disable beam production by interlocking both RF power and laser emission. The AGS started its heavy ion program on schedule April first. The program will run for one month, then switch over to protons beginning June first. The High Energy Physics program is scheduled to run uninterrupted until January of 1998 when preparations for RHIC commissioning will begin. It has been several years since the AGS has run more than a few months of protons without a scheduled maintenance period. One of our concerns will be the failure of key magnet elements in high radiation areas which may result in significant dose being received during repairs. We have factored this into our ALARA goals for this year. The addition of a beam scraper in the main ring later in the year may alleviate this concern by causing much of the activation to be "collected" at a single point which is removed from the more travelled areas of the ring. It is hoped this will lower the residual dose rates from the extraction elements. ------------------------------------------------------------------------ News from Center for Advanced Microstructures and Devices (CAMD) Lorraine Day ------------------------------------------------------------------------ Things at CAMD continue to "accelerate". The wiggler, installed during the Christmas season, is being removed for upgrading and conditioning at the Budker Institute, Novosibirsk, Russia. During the planned shutdown, alterations, upgrades and re-commissioning of the CAMD radiation interlocks will take place. The original shielding configuration will replace the wiggler, at least temporarily. Removal of this shielding had previously been shown to create a line source which was above the 7 foot shield wall. CAMD is unique in that the synchrotron ring does not have a shielding roof. In part, this is possible because the injection is low energy (200 MeV) and secondly, injection is normally completed within one minute. This is an exceptional time for a machine of this type. We are currently building three new beamlines - a toroidal grating monochromator (6M in length), a variable line spacing spectrometer (both will operate in the UV range - which is good news for radiation safety) and a normal incidence monochromator which poses some interesting shielding challenges in that the end chamber sits above the shield wall and the beamline actually bends back towards the current shield wall. The accelerator physics group is working on an RF upgrade (potentially more health physics problems) as well as many changes in machine operation. However, at least for the moment, the duty cycle of the linac remains unchanged. The Linac output accounts for > 90% of all the radiation produced in the facility. Here is an interesting loophole in which we recently found ourselves. As a university facility, we are forced to use the university's maintenance staff. Naturally, everyone who works out at CAMD is trained and badged. Last Monday, it was learned that maintenance sent two persons (of about a ten person group) to the facility. Both had been trained in radiation safety, but one of these individuals' training had expired and neither was currently badged because they had been removed from the list of approved persons. During the original training, it was clearly explained and understood by supervisors in the presence of human resources personnel that no one could be sent to CAMD without a badge (or obviously proper training). Somehow they disregarded this rule and substituted staff without telling anyone. These people were let into the experimental hall (requires computer coded access card by their supervisors). Sometimes training doesn't appear to be enough and reprimands are not looked upon with favor in the university environment. Funding problems mean that I will not likely have the opportunity to meet with other health physics colleagues in July. We are also under a new administrative staff which always makes things interesting ! ------------------------------------------------------------------------ News from CERN Manfred Hoefert ------------------------------------------------------------------------ This time CERN's contribution to the IARPE Newsletter is rather short as members of Radiation Protection group were rather busy with other activities like the annual shut down of CERN's accelerators and subsequently their starting up, writing the various chapters of RP's annual report for 1997, and performing the yearly interviews for the staff. Therefore, I would like to address only two topics, i.e., answer Ralph Thomas' comment on my report about the STOA workshop in Brussels and make a plea for an international collaboration in the field of radioactive material from accelerators that is no longer to be used. Ralph, I appreciate that you confirm my suspicion and answer my rhetoric and ironic question on ICRP positively. So even in the early days ICRP's wise men were not always so rational in their statements than at least I was made to believe when I started in the radiation field in 1961. Since then the number of "oblique" formulations in ICRP documents has become legion and I consider as a miracle that there is in large still global exception of their Recommendations while even in the field of religion we are left with four major and many minor choices. With respect to ICRP fundamentals there have already been many heretic statements but a religious war with all its ugly consequences has so far been avoided. Dear colleagues, in recent years the topic of radioactive material from accelerators that is no longer to be used (you notice that I hesitate to use the words radioactive waste) has become an important issue at CERN. The obvious reason is that we have run out of space particularly since we were forced due to political reasons to store all scrap even of very low specific activity under the roof. When, however, we tried to get rid of the material as inactive we met insurmountable difficulties. When we then tried to hand over to the official Agency in France material with some higher specific activity as normal radioactive waste we encountered an unexpected opposition. Both attitudes are to a great deal born out of two adverse opinions. On the one hand radioactive material from accelerators is readily assimilated to waste from nuclear power plants, on the other hand there is fear that there may be unknown and therefore dangerous radionuclides formed by spallation present in accelerator waste. It is my firm opinion that the two categories of radioactive waste should not be placed into the same basket. High-energy accelerators produce radioactivity that, with only some rare exceptions, consists of beta-gamma emitting materials of metallic nature where the radiologically important radionuclide with the longest half life is Co60. There is usually no contamination risk. In view of in many cases low specific activities involved these valuable materials should be recycled rather than being thrown to the waste (this explains my hesitation above). At this place I would like to give again great credits to Jan Tuyn of my group who in collaboration with his many students, fellows and visitors has created a wealth of knowledge in the field of accelerator activated material. With all the more political difficulties CERN has encountered in the field so far, I brought, during my recent visit to the IAEA in Vienna, the topic to the attention to Dr. Abel Gonzales, Director of Nuclear Safety, Radiation and Waste. He agreed that the matter of activated material in accelerators deserves special attention and asked me to exploit the possibility for an IAEA TECDOC on the subject. I agreed to write a preliminary draft but suggested to create a small working panel composed out of one colleague from Japan (KEK), Russia (Dubna or IHEP) and the US (Brookhaven, Fermilab or SLAC) with some experience in the field of radioactive material and willing to collaborate on the subject. It is clear that we must consider smaller accelerators too but the bulk of radioactivity is found in our big machines to be decommissioned one day. Ladies and gentlemen, I therefore ask you to manifest your interest and to send me an e-mail such that I can send you the draft material when it is ready. ------------------------------------------------------------------------ News from Fermilab Kamran Vaziri ------------------------------------------------------------------------ The Fermilab Main Injector (MI) is nearing completion, with the commissioning scheduled for August this year. Fixed Target start up and Tevatron testing are planned for February 1999. The Safety Assessment Document for the Main Injector with coasting and accelerated beam and its associated Recycler Ring has finished. The Recycler Ring allows for the recycling of 80-90% of the anti-protons that are left unused during each collider run. The Accelerator Readiness Review is currently under way. This review is a joint effort between, the Fermilab, DOE Area Office and the DOE Chicago Headquarters. A combined team, led by the Fermilab ES&H Section, is conducting this review. Recently, invited external reviewers from BNL and SLAC came to Fermilab to help with this review. The recent discovery of damage caused by micro-organism in the MI Low Conductivity Water loop, and the subsequent radiography of all the welds and repairs, have delayed the installation and commissioning of the permanent magnet anti-proton storage ring (dubbed the Recycler Ring). However, the Recycler Ring is an integral part of the MI facility and it is scheduled to be commissioned before the February 1999 date. ------------------------------------------------------------------------ HP Operational Experience from Elaine Marshall : A recent incident involving a potentially contaminated wound raised several issues affecting our emergency response to situations where radiation and/or radioactive materials may be involved. Bloodborne pathogens are of considerable concern in the workplace these days, given the public attention to hepatitis and HIV. Biologically decontaminating radiological instruments would not only be difficult but also significantly increase the risk of exposure to instrument technicians. Care should also be taken to prevent contamination of the wound with foreign materials. As a result, members of our Instrumentation Team investigated several "shields" and their effects on instrument response and efficiency to accelerator produced isotopes. For personnel contamination surveys, a frisker type instrument with a pancake probe, usually a Ludlum 44-9 or Eberline E140N, is used. In summary, a sandwich bag provided adequate protection of the probe while only reducing instrument response about 10%. A surgeon's glove, which might be used for its sterility, resulted in a 50+% reduction in response. Fermilab Radiation Physics note 132 describes this study in detail. ------------------------------------------------------------------------ News from Jefferson Lab Scott Schwahn ------------------------------------------------------------------------ A couple months ago, we formally tested the production ability of the Free Electron Laser (FEL) by irradiating several batches of solid ammonia and deuterated ammonia in a liquid argon dewer (to produced polarized centers in the ammonia). This was our first real chance to empirically verify the dump shielding and integral shielding which makes up the structure of the accelerator vault and above-ground user laboratory. The experiment required some analysis for radionuclide production in the liquid, releases to the air, direct radiation from the dewer (both prompt and induced), as well as full mockups for handling. We (meaning the RadCon Group) made sure to insert ourselves into the process in the very early planning stages (even during the theory stages, where we found an error in the PC distribution of EGS4!). This effort paid off in the end and saved us a lot of trouble, as a short 4-hour run produced approximately 2E10 Bq (0.5 Ci) of Cl-39 from the (gamma,p) reaction from Ar-40. The successful cooperation of our group with the experimenters helped to reduce the time for all the planned irradiations to half of the alloted time and was a big feather in the cap of the FEL team. The targets produced will be used for an entire year's worth of experiments in Hall C. Thanks mostly to the efforts of the Jefferson Lab User Liaison Office, Keith Welch, our Training Manager, and Becky Nevarez, our records custodian, we have a web site now. Take a look when you get a chance. We're pretty please with it, at least in concept, and are working to improve it. It includes commonly used forms, training guides, and will eventually have on-site online testing. You can find it at . ------------------------------------------------------------------------ News from RHIC Stephen Musolino ------------------------------------------------------------------------ The Relativistic Heavy Ion Collider (RHIC) is nearing completion and moving towards commissioning of the collider and experiments. There is still much work ahead to complete the safety analysis of the complex and turn the results into operations procedures and training. The Department of Energy conducted an Independent Safety Review of the preparations to complete all the necessary reviews to start commissioning and eventually lead to routine operation of the complex. Initial cooldown of the cryogenic system is scheduled to commence in December,1998 with colliding gold beams expected in January, 1999. After this initial operation of the collider there will be a shutdown followed by an engineering run with beam to test detector systems and finalize collider commissioning. Then in FY2000 the completed complex will enter into an extended run for physics. It is expected that the predicted quark-gluon state of matter will be discovered. After all the media attention over the past year that the Laboratory has received over the environmental practices in the decades that proceed the promulgation of the environmental laws, interestingly one of the most significant ES&H aspects of RHIC has been with respect to groundwater protection. It is a reflection of where the attitudes about radiation has gone in society. We will commit significant resources to meet the EPA drinking water standards in water that the laws of nature will prevent any person from ever drinking. One RHIC physicist put it very well, "In the past we used to use the earth to protect us, now we must protect the earth." Seen on RadSafe: "Beneath this chaos is a really big mess." - Jim Davis ------------------------------------------------------------------------ First Announcement of ICRS-9, Ninth International Conference on Radiation Shielding Takashi Nakamura ------------------------------------------------------------------------ This conference, ICRS-9, has been subtitled as "Half a Century of Radiation Shielding Research and Its Evolution into the Next Era", and is to be held from October 17 (Sunday) to October 22 (Friday), 1999 at Tsukuba, Japan; it is being organized by Japan Atomic Energy Research Institute(JAERI) in collaboration with OECD/NEA-NSC (Nuclear Science Committee), Atomic Energy Society of Japan and ORNL/RSICC (Radiation Safety Information Computational Center). Topics of this conference are as follows: Fission Reactor Shielding Accelerator and Target Shielding Fusion Reactor Shielding Aircraft and Spacecraft Shielding Radioactive Waste Radiation Protection and Safety Fuel Cycle Facility Shielding Transportation and Storage of Radioactive Materials Decontamination and Decommissioning Impact of Radiation and Radioactivity to Environment Radiation Applications in Medical and Industrial Uses Shielding Calculation - Monte Carlo Methods, Deterministic Methods, Point Kernel and Other Analytical Methods Shielding Experiment - Benchmark Experiments, Integral and Mockup Experiments Shielding Design Methods Verification and Validation Visualization and User Interface Source Term Evaluation Skyshine and Streaming Nuclear Data for Shielding Field Characterization Radiation Dosimetry Radiation Detection and Measurement Shielding Materials and Irradiation Effects Activation and Induced Radioactivity Exposure Evaluation and Protection Deadline for Abstracts: Jan. 31, 1999 Notification of Authors: March 31, 1999 Call for Papers in the Second Circular around June, 1998 General Chairperson: Shinzo Saito (JAERI) International and Local Program Committee Chairperson: Takashi Nakamura (CYRIC, Tohoku University) Conference Secretary: Yujiro Ikeda (JAERI) e-mail: Please pre-register from the ICRS-9 Home Page: ------------------------------------------------------------------------ In Memoriam Keran O'Brien ------------------------------------------------------------------------ Oak Ridge's Fran Alsmiller died in the fourth of February. Fran, the wife of Tut Alsmiller was a brilliant physicist who contributed greatly to the theory of high-energy transport, radiation transport in general, and to the development of HETC. A brilliant woman and a dear friend. ------------------------------------------------------------------------ HOW TO SUBSCRIBE / UPDATE YOUR E-MAIL ADDRESS ------------------------------------------------------------------------ To add yourself to the mailing list for the IARPE Newsletter, send an e-mail message to listserv@slac.stanford.edu The body of your message should contain the following command: subscribe iarpe-l Please don't forget to update your e-mail address if you move, change jobs or just change your computing environment. The update consists in canceling the old by 'unsubscribe' and submitting a new subscription, as illustrated below: unsubscribe iarpe-l your_old_email_address subscribe iarpe-l end If the body of your message, as in this example, contains more than a single line/command, it is good practice to finish with the 'end' command, especially if your mailer adds a signature. If you experience problems with subscribing/updating, please send me an e-mail to schwahn@jlab.org and I will do it for you.