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Information Notice No. 93-86: Identification of Isotopes in the Production and Shipment of Byproduct Material at Non-Power Reactors
UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF NUCLEAR REACTOR REGULATION WASHINGTON, D.C. 20555 October 29, 1993 NRC INFORMATION NOTICE 93-86: IDENTIFICATION OF ISOtopES IN THE PRODUCTION AND SHIPMENT OF BYPRODUCT MATERIAL AT NON-POWER REACTORS Addressees All holders of operating licenses or construction permits for test and research reactors. Purpose The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice to alert addressees to a problem with the identification of isotopes in byproduct material produced and shipped at a non-power reactor. It is expected that recipients will review the information for applicability to their facilities and consider actions, as appropriate, to avoid similar problems. However, suggestions contained in this information notice are not NRC requirements; therefore, no specific action or written response is required. Description of Circumstances In response to NRC concerns regarding shipping errors at the University of Missouri-Columbia Research Reactor Facility (MURR), the licensee established a task force to review the shipping of byproduct material produced in the reactor. When the task force reviewed the information on target composition (isotopic enrichment, impurities, or encapsulation) and isotopes to be produced submitted by requesters of irradiation services, the task force found 17 target types that had been submitted with incomplete information. Because the licensee accepted the incomplete information from the requesters, some of the isotopes produced by irradiation of the targets in the reactor were not listed on the shipping papers. Apparently, the target composition information submitted by the requesters contained only the isotope(s) of interest to the requesters and did not contain other isotopes that would be produced in the target. The task force determined that less than 90 percent of the total sample activity was reported on the shipping papers for the 17 target types. The task force also found that the calculations of expected isotope activity levels submitted by requesters were accepted without independent licensee verification. A particularly significant example in which activity levels were understated on the shipping papers concerned the irradiation of a sample of ytterbium (Yb). The isotope of interest to the requester was Yb-169 (half-life of 32.03 days) which was listed on the request for irradiation form. MURR accepted this information as listed on the request form and the sample was shipped as containing 592 MBq [16 millicuries] of Yb-169. However, 9310250225. IN 93-86 October 29, 1993 Page 2 of 3 conservative calculations (which ignored self shielding or flux perturbations) showed that up to 185,000 MBq [5 curies] of Yb-175 (half-life of 4.19 days) may have been in the target when it was shipped. Another concern was found in the manner that facility personnel used the information prepared for irradiation of targets. For irradiation experiments, MURR prepares safety analyses called reactor utilization requests that contain comprehensive information on the isotopes that will be produced in irradiated targets. The technicians who prepare the targets for irradiation refer to summary sheets of pertinent data taken from the prepared reactor utilization requests. However, there was no administrative mechanism to ensure that the data on the summary sheets is updated if changes were made to the reactor utilization requests. To correct the problems with preparation of shipping papers, MURR will measure directly the activity of samples for shipment if feasible. Where direct measurement is not feasible, MURR will calculate the activity produced in the target. The activity of samples of phosphorus-32 and sulfur-35 will be determined by reference to previously verified activities for identical targets with similar irradiation histories. To correct the problem with the use of summary sheets, MURR committed to develop a mechanism to ensure that the summary sheets are updated to reflect any pertinent changes to information on the reactor utilization requests. Discussion The circumstances described above demonstrate the importance of licensee verification of information on targets (isotopic enrichment, impurities, encapsulation, isotopes produced) for insertion into a non-power reactor. In accordance with technical specifications, licensees are responsible for ensuring that targets meet the requirements of an approved safety analysis. The calculations for these safety analyses evaluate the effects of irradiating the target material and assist in the determination of health physics and shipping requirements for isotopes produced by the irradiation. Identification of these isotopes is important for radiation protection of plant personnel and also for documenting the makeup of the irradiated target prior to shipment. Title 10 of the Code of Federal Regulations, Part 71, Section 5(a)[10 CFR 71.5(a)] requires that licensee who transport licensed material outside the confines of their plants or deliver licensed material to a carrier for transport, shall comply with the applicable requirements of the regulations appropriate to the mode of transport of the Department of Transportation (DOT) IN 49 CFR 170-189. DOT regulation 49 CFR 172.203(d) requires that shipping papers specify, along with other information the activity contained in each package of the shipment in terms of curies, millicuries, or microcuries and the name of each radionuclide. Improper identification of isotopes in a sample could present a hazard to personnel who handle or package the samples for shipment, may result in incorrect shipping papers and package labeling . IN 93-86 October 29, 1993 Page 3 of 3 which could be misleading during shipping emergencies, and could cause unnecessary or incorrect exposure if the isotopes are used without verification by the end user. This information notice requires no specific action or written response. If you have any questions about the information in this notice, please contact one of the technical contacts listed below or the appropriate Office of Nuclear Reactor Regulation (NRR) project manager. Brian K. Grimes, Director Division of Operating Reactor Support Office of Nuclear Reactor Regulation Technical contacts: A. Adams Jr, NRR (301) 504-1127 C. Cox, RIII (708) 790-5298 Attachment: List of Recently Issued NRC Information Notices.
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