Protecting People and the EnvironmentUNITED STATES NUCLEAR REGULATORY COMMISSION
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS
WASHINGTON, D.C. 20555
March 6, 1991
Information Notice No. 91-16: UNMONITORED RELEASE PATHWAYS FROM
SLIGHTLY CONTAMINATED RECYCLE AND
RECIRCULATION WATER SYSTEMS AT A FUEL
FACILITY
Addressees:
All fuel cycle facilities.
Purpose:
This Information Notice is intended to alert addressees to potential
problems resulting from using runoff water and process effluents, both
contaminated with radioactive materials, in non-nuclear processes. At one
fuel facility, the use of these liquids resulted in a concentration and/or
release of radioactive material, without an evaluation, to unrestricted
areas. 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 do not constitute U.S. Nuclear Regulatory Commission (NRC)
requirements; therefore, no specific action or written response is required.
Description of Circumstances:
A fuel facility's recycle water system was used to provide water for
non-contact cooling of plant systems, the fire protection system, sanitary
facilities, a grit blaster, and gaseous effluent scrubbers. Makeup water
for the system was partially obtained by collecting rain water from roof and
storm sewer drains. The makeup water became contaminated by particulate
fallout from effluent discharges onto the buildings and the nearby ground
areas. As a result, the recycle water system became contaminated.
The licensee had routinely analyzed the recycle system water for gross alpha
radioactivity. However, the licensee failed to evaluate either the
processes which used recycle water and could concentrate the uranium or the
release pathways from the recycle water system which released excess water
during heavy rain storms. The pathways included overflows from the system
reservoir, the cooling tower, and the roof and storm sewer drains. The
runoff eventually drained to a nearby river without an analysis for
radioactivity. As a result, unmonitored release pathways existed for low
levels of radioactivity.
Another unmonitored release pathway for the recycle system was from the
facility's fire protection system, which used recycle water as the supply
source. When the fire protection system's booster pumps were tested, the
pumps discharged onto the open ground. No samples were analyzed for
radioactivity before these
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IN 91-16
March 6, 1991
Page 2 of 3
releases. Additionally, recycle water was periodically provided to a local
fire department to refill the water-storage tanks in its fire truck, without
analysis for radioactivity. The licensee was aware that the recycle system
was slightly contaminated but thought that the transfers of radioactively
contaminated water were allowed because the concentrations were below the 10
CFR Part 20 release limits.
Another example of an unmonitored release pathway from the recycle system
was from gaseous effluent scrubbers that used the slightly contaminated
recycle water for particulate removal. The gaseous exhaust from the
scrubbers had been routinely sampled for nitrous oxide but not for
radioactivity. Additionally, contaminated scrubber water from two fume
scrubbers had been discharged to a nonradioactive holding pond. The pond
was part of the licensee's nonradioactive liquid waste treatment facility,
and the introduction of the contaminated water may have caused radioactive
contamination of the pond.
Recycle water was also used in the licensee's zirconium and copper recovery
processes. The recycle water was used in the zirconium recovery process as
part of the cleaning process. After recovery, the zirconium was then
packaged and sold to various offside vendors without testing for radioactive
contamination. In the copper recovery process, the recycle water was used
in the associated scrubber for gaseous effluents. Since contaminated
recycle water was used in the scrubber, the transfer of water to the
recovery system could have contaminated the copper recovery system and the
final copper oxide product. Without testing for radioactive contamination,
the product was sold to offsite vendors for use in various products.
Another water system used for the scrubber water was the recirculation water
system. During 1984, the licensee installed the recirculation water system
which diverted a portion of the final effluent for use in the liquid waste
treatment facility. This effluent contained low concentrations of
radioactive isotopes that were below 10 CFR Part 20 release limits. The
recirculation water was used in the liquid waste treatment facility to
prepare the lime slurry for use in both the radioactive and the
nonradioactive waste treatment operations to neutralize the acidic solutions
and to precipitate fluorides and metals such as aluminum, chromium,
zirconium, and uranium. The precipitated sludge from the radioactive waste
treatment was shipped offsite for disposal as low-level radioactive waste.
The precipitated sludge from the assumed nonradioactive water treatment
system was buried onsite in a State-permitted landfill. However, this
sludge contained radioactive contaminants from the recirculation water lime
slurry, and the State-permitted landfill was not authorized to receive
radioactive material.
The licensee has initiated and/or completed corrective actions for both the
recycle and the recirculation water systems to eliminate the sources of
radioactive contamination and to evaluate all release points. The licensee
has eliminated the use of radioactively contaminated recirculation water in
the recovery operations and ceased onsite burial of the radioactively
contaminated sludge. Further corrective actions will include
characterization of the onsite burial areas.
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IN 91-16
March 6, 1991
Page 3 of 3
Discussion:
Licensees are reminded that they must make surveys to assure compliance with
10 CFR 20.301 which describes authorized means of disposal of licensed
material in waste and must make surveys to assure compliance with 10 CFR
20.106 which limits the yearly average concentration of radioactive material
in air or water discharged to unrestricted areas. Furthermore, licensees
are reminded that changes in plant design must be evaluated to determine
whether the changes will result in the unmonitored release of radioactive
material to unrestricted areas.
This Information Notice requires no specific action or written response. If
you have any questions about the information in this notice, please contact
the technical contact(s) listed below or the appropriate NRR project
manager.
Richard E. Cunningham, Director
Division of Industrial and
Medical Nuclear Safety
Office of Nuclear Material Safety
and Safeguards
Technical Contacts: Susan S. Adamovitz, Region II
(404) 331-4774
Edwin D. Flack, NMSS
(301) 492-0405
Attachments:
1. List of Recently Issued NMSS Information Notices
2. List of Recently Issued NRC Information Notices
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