Protecting People and the EnvironmentUNITED STATES NUCLEAR REGULATORY COMMISSION
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.
