Information Notice No. 95-55: Handling Uncontained Yellowcake Outside of a Facility Processing Circuit
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS
WASHINGTON, D.C. 20555-0001
December 6, 1995
NRC INFORMATION NOTICE 95-55: HANDLING UNCONTAINED YELLOWCAKE OUTSIDE OF A
FACILITY PROCESSING CIRCUIT
All Uranium Recovery Licensees.
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information
notice to alert addressees to the hazards associated with the handling of
uncontained yellowcake (natural uranium) at uranium recovery facilities. 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
new NRC requirements; therefore, no specific action nor written response is
Description of Circumstances
During a routine NRC inspection of an operating conventional uranium mill, the
inspector discovered that the licensee had used an unorthodox method for
drying yellowcake which could have resulted in significant airborne exposure
to workers. No worker received an internal exposure in excess of regulatory
limits because of the careful work practices and procedures used for this job.
Fifteen barrels of yellowcake were stored outside for several months.
Inleakage through the barrel bung holes resulted in the contents becoming wet
and requiring re-drying before shipment. The licensee was unable to use the
conventional yellowcake drying circuit of the mill because of delays in
receiving a state permit to use this equipment; therefore, the licensee
resorted to spreading the yellowcake over a 38 ft2 trough and using propane
heaters placed above and below the trough to dry the material. The material
was dried in batches, and at various intervals workers raked the material to
enhance the drying process. Afterwards, the yellowcake was shoveled back into
the barrels. During this work the area was washed down on several occasions
to reduce airborne concentrations and surface contamination. The wash water
was routed to a process sump.
Air sample results ranged as high as 40 times the Derived Air Concentration
for natural uranium specified in 10 CFR 20, Appendix B. However, use of
safety measures, such as respiratory protection and protective clothing,
resulted in no detectable levels of uranium in worker urine bioassay samples.
9511300301. IN 95-55
December 6, 1995
Page 2 of 3
Licenses issued to uranium recovery facilities do not specifically prohibit
the kind of activity described above. However, NRC would expect that
appropriate management oversight and planning would eliminate any need for
such activities. Since production facilities and equipment are designed to
reduce direct exposure to yellowcake by mill workers, special tasks that
bypass these engineered controls should normally be avoided but, if required,
be planned with special care to reduce worker exposure.
NRC requires that production facilities and equipment be designed: 1) to
reduce or eliminate worker contact with yellowcake during product drying and
packaging; and 2) to reduce emissions of dried yellowcake to prevent exposures
to workers as well as members of the public. In particular, dryer enclosures
are required and are designed to be maintained at a negative pressure relative
to other mill areas in order to reduce yellowcake outleakage. Also, filtering
components reduce yellowcake emissions from dryer stacks. These design
requirements assume that direct contact with dried yellowcake by workers will
occur only rarely and then only with relatively small quantities.
Uranium processing licensees occasionally may be required to handle
yellowcake. Sampling may disclose that a product batch does not meet customer
specifications and must be re-introduced manually into the process circuit.
On occasion, yellowcake must be transferred from one drum to another. Such
manual maneuvers have a high potential for airborne contamination and worker
Licensees are advised to take measures to minimize the need for special
handling of yellowcake product outside of the processing circuit. When such
work is required, these tasks should be carefully planned to reduce the
potential for airborne contamination and worker exposure.
Each licensee is responsible for protecting the public health and safety by
ensuring that all NRC requirements are met and that any potential hazards are
promptly identified, corrected, and, if necessary, reported. This
responsibility can only be fulfilled if there is persistent and adequate
management oversight of licensed activities.
. IN 95-55
December 6, 1995
Page 3 of 3
This information notice requires no specific action or written response. If
you have questions about the information in this notice, please contact the
technical contact listed below.
John T. Greeves, Director
Division of Waste Management
Officer of Nuclear Material Safety
Technical contact: Chuck Cain, RIV
1. List of Recently Issued NMSS Information Notices
2. List of Recently Issued NRC Information Notices
Page Last Reviewed/Updated Wednesday, March 24, 2021