MIT Reports to the President 19992000
During the past year the Nuclear Reactor Laboratory (NRL) continued its joint interdisciplinary activities with both MIT and non-MIT collaborators, including academic departments and interdepartmental laboratories and a number of other universities, schools, and nonprofit research institutions such as teaching hospitals. These joint research or teaching and training activities cover a wide spectrum in the life and physical sciences and in engineering, including development of cancer therapy, nuclear engineering, computer control of reactors, training in reactor operations, dose reduction and materials performance in power reactors, radiochemistry and trace analysis applied to the health effects from energy use, nutrition, earth and planetary sciences, environmental studies, and nuclear medicine.
There were two especially noteworthy developments during the past year. Both concerned the continued program in joint research with Beth Israel Deaconess Medical Center on the treatment of cancer utilizing the boron neutron capture method. The first was that construction and pre-operational testing of the fission converter facility was completed this year. This facility provides MIT with the best epithermal neutron beam for boron neutron capture therapy in the world. The second was the receipt from the U.S. Nuclear Regulatory Commission of approval for operation of the fission converter facility.
The prompt gamma neutron activation analysis facility was used both for research and in support of the neutron capture therapy clinical trials.
Professor Frederick A. Frey, Department of Earth, Atmospheric and Planetary Sciences, and Dr. Pillalamarri Ila supervise operation of the Neutron Activation Analysis laboratory which is part of the Center for Geochemical Analysis within the Earth, Atmospheric and Planetary Sciences Department. Trace element abundances are determined in a wide range of natural materials. Currently the laboratory is focused on analyses of volcanic rocks recovered during the ongoing Hawaiian Scientific Drilling Project and the recently completed Leg 183 of the Ocean Drilling program which focused on sampling the very large igneous province that forms the Kerguelen Plateau.
Dr. Jacquelyn C. Yanch, Department of Nuclear Engineering, continued as head of the NRLs Trace Analysis Laboratory. She was joined by Dr. Pillalamarri Ila and together they continued to make the NRLs neutron activation analysis (NAA) facilities and expertise available to industry, other universities, private and governmental laboratories, and hospitals. Research and/or service-oriented collaborations were continued with several MIT research laboratories as well as with other educational and research institutions including: University of Miami, Harvard, California Institute of Technology, Tufts University, University of Utah, University of Connecticut, and University of Arizona.
Within MIT, research support has been provided to several departments. This research support includes analysis of various environmental and biological samples for trace and toxic metals for Professor William G. Thilly (Center for Environmental Health Sciences) as well as for faculty in both the Department of Civil and Environmental Engineering and the Department of Chemical Engineering.
A three-year collaborative grant to study the formation and emission of toxic substances from coal combustion continued with support from the U.S. Department of Energy. The ER&R facilities were used extensively in Course 12.119 Environmental Geochemistry.
A number of other research applications of NAA are summarized in a subsequent section, Reactor Irradiations for Research Groups outside MIT.
Clinical phase-I trials of boron neutron capture therapy (BNCT) for melanoma on the extremities were successfully performed up to the second dose level of 1250 RBE-cGy in the mid-1990s. Five irradiations were completed. No adverse reactions were observed on the subjects. However, three of the five lowest dose irradiations of deep-seated melanoma resulted in significant tumor regression. In one case a subject had two separate melanoma lesions irradiated at different times; four years later she is disease free in the irradiated areas. This trial remains open.
Phase-I studies of brain cancer, brain metastases of melanoma, and glioblastoma multiforme were performed from 19961999. Twenty-two volunteer subjects were irradiated, and the fifth dose level of 1420 RBE-cGy was reached. One serious adverse reaction was observed at one of the lower dose levels. It is unclear if this was because of the BNCT irradiation. Several of the brain tumor subjects experienced improved performance following the experimental BNCT irradiation. One intracranial melanoma showed essentially complete regression. This trial, which used the MITRs M67 epithermal beam, was successful in terms of the objectives of a Phase-I protocol. However, therapeutic dose levels were not reached. This trial is now closed. A new trial that uses the new fission converter beam that is described below is planned for 2001.
A fission converter based epithermal neutron beam irradiation facility for BNCT has been constructed over a period of 2.5 years and successfully put into operation during this year. The intensity of this beam has been measured and it is the highest intensity beam available anywhere in the world. The beam quality has also been experimentally verified and it is of near theoretical purity. When the electronic control system is completed this facility will be ready for irradiations of deep seated tumors, probably by early 2001. Irradiation times will be as short as a few minutes and therapeutic ratios (dose to tumor/dose to normal tissue) will be 45, a doubling over the therapeutic ratio available with the current MIT epithermal neutron beam.
This new facility will be the key component in future clinical tests of the efficacy of BNCT for cancer. It will also assure that MIT will maintain its leadership role in this research area.
A contract has been obtained from the US DOE for the reconstruction of the medical irradiation beam in the basement of the MITR. When completed this facility will provide a high intensity and high purity thermal neutron beam for BNCT irradiations of small animals and superficial human cancers.
BNCT research at the MIT Research Reactor is under the direction of Professor Otto K. Harling and is carried out in collaboration with the medical staff at the Beth Israel-Deaconess Medical Center. Six MIT graduate students are completing their theses on these projects.
The NRL supports a subdiscipline in the Nuclear Engineering Department (NED), Radiation Health Physics, by providing relevant research opportunities. The NRL also contributes to a specially designed laboratory and demonstration course. This course, 22.09/22.104, Principles of Nuclear Radiation Measurement and Protection, is appropriate for all students in NED. Research topics and support for Health Physics students were provided by NRL projects, especially the BNCT and Dose Reduction projects of Professor Otto K. Harling.
Dr. John A. Bernard, who is certified as a Health Physicist by the American Board of Health Physics, continued to teach course 22.581, Introduction to Health Physics. This course uses the MIT Research Reactor to provide practical examples of health physics issues.
An experiment to study the shadow corrosion behavior of Zircaloy under prototypical boiling water reactor conditions through use of an in-core autoclave was successfully completed. Zircaloy specimens were exposed in-core and near-core in close proximity to a variety of other materials. This program was under the direction of Dr. Gordon Kohse and Professor Ronald Ballinger of the Nuclear Engineering Department and was funded by ABB Nuclear of Sweden.
A new in-core autoclave facility is now being built to study the effect of radiation on candidate ceramic clads. The benefit to the use of such clads is the elimination of the potential for a steam-zircaloy reaction that now exists with the zirconium-based clads that are currently in use. The program is funded by Gamma Engineering Corporation under a DOE Nuclear Engineering Research Initiative Grant.
Dr. Bernard continued to teach course 22.921, Reactor Dynamics and Control, and to offer review classes on engineering fundamentals for NED students in the radiological sciences. Both activities make use of the reactor for illustrating theoretical concepts. The program on the digital control of nuclear reactors continued with thesis activity in the area of automated diagnostics.
The relicensing of the MITR with a concomitant upgrade in power is in progress. It was previously identified that the MITR could operate at a maximum power of 67 MW with the existing heat removal equipment. A decision was subsequently made to submit the licensing documents for a power increase from 5 MW to 6 MW. On July 8, 1999 a formal application was submitted to the U.S. Nuclear Regulatory Commission (NRC) to relicense the reactor for an additional twenty years and to upgrade the power level to 6 MW. The relicensing package included a complete rewrite of the Safety Analysis Report and the Technical Specifications. The NRC has authorized the continued operation of the MITR pending its review of the application. That process remains ongoing. In conjunction with the relicensing effort, reactor systems are being upgraded. Both the internal and the environmental radiation monitors were replaced in 1998. The cooling tower and major portions of secondary piping were replaced in 1999. Upgrades to electrical distribution systems are planned for 2000.
In nuclear medicine, the development and/or continuing production of radioisotopes for use by researchers at hospitals and other universities included investigations using track etching techniques by Dr. David Slaughter of the University of Utah to determine the uptake pattern of heavy metals by humans as well as the environment, and evaluation of copper and gold for arthritis treatments by Dr. Alan B. Packard of Childrens Hospital.
In a number of other areas reactor irradiations and services were also performed for research groups outside MIT. Most of these represent continuations of previous research. Examples include Dr. Alan P. Fleer of Woods Hole Oceanographic Institute who used irradiation to determine natural actinides and plutonium in marine sediments and Dr. Rebecca Chamberlain of the Los Alamos National Laboratory who is investigating calibration of ultra-sensitive neutron monitoring devices by thermal neutron fission of uranium foils.
Whereas most of the outside users pay for irradiation services at the reactor, educational institutions needing such services for their own academic or research purposes are assisted in this regard by the USDOE through its "Reactor Sharing Program." A grant to MIT NRL reimburses us for the costs of providing irradiation services and facilities to other not-for-profit institutions (including teaching hospitals and middle and high schools). Under this program, 500 students and 50 faculty and staff from over 30 other educational institutions benefited from visits to and use of the MITR during the past year.
Research utilization of the MITR by other institutions under the Reactor Sharing Program during the past year has included: use by Professors J. Christopher Hepburn and Rudolph Hon of Boston College to activate geological specimens and standards for the NAA of rare earth and other trace elements in studies of the geological development of the northeastern United States; irradiation of air particulate samples for NAA by Professor Gerald Keeler of the University of Michigan; gamma irradiation of plant seeds for several area high school students participating in science fair projects; measurements of boron concentration and work on high resolution track etch autoradiography for Professor Robert Zamenhof of Beth Israel-Deaconess Medical Center; participation in several special high school student projects; neutron activation analysis of subsurface water supplies by Professor Jack Beal at Fairfield University; neutron time-of-flight and Bragg angle measurements by Professor Martin Posners group at the University of Massachusetts; and use of gamma radiation by Dr. Mark Wimer of the Beth Israel/Deaconess Medical Center to sterilize artificial ligaments that are being evaluated in animal models.
For education of the general public and students at all levels in local and other New England schools, the reactor staff provides lectures and tours periodically throughout the year. One local university incorporated reactor visits and experiments into its regular course curricula, as follows: The University of Massachusetts, Harbor Campus, Professor Martin Posner, Department of Physics, Physics (Course #603).
A major project to neutron transmutation dope semiconductor grade silicon single crystals continued for a successful seventh year. Approximately 10 metric tons of Si crystals were accurately irradiated in shielded, automated irradiation facilities at the MITR. This project is under the technical direction of Professor Otto K. Harling.
The NRL supports the affirmative action goals of the Massachusetts Institute of Technology. Of a staff of 36 there are currently five engineering and management positions held by minorities and women. The NRL participated in the US DOEs program for minority training in reactor operations, and one of our current senior reactor operators is a graduate of this program.
The MIT Reactor completed its 42nd year of operation, its 26th since the 197475 shutdown for upgrading and overhaul. The reactor operated continuously (seven days per week) to support major experiments. On average, the MIT Reactor was operated 95 hours per week at its design power level of 5 MW. Energy output for the MITR-II, as the upgraded reactor is now called, totaled 477,000 megawatt-hours as of June 30, 2000. The MITR-I generated 250,445 MW in the sixteen years from 1958 to 1974.
To summarize briefly the reactor was well utilized during the year, although still more experiments and irradiations can be accommodated because of the number and versatility of the many experimental facilities. The number of specimen irradiations was 300. There were 39 irradiations in the medical rooms, many in support of the neutron capture therapy program for the treatment of brain cancer and subcutaneous melanoma. Theses and publications on research supported by the reactor are running at about 15 and 30 per year, respectively. A total of 1031 people toured the MIT Research Reactor from July 1, 1999 through June 30, 2000.
More information about this department can be found on the World Wide Web at http://web.mit.edu/nrl/www/bnct.html.
John A. Bernard
MIT Reports to the President 19992000