DRC-2009-001284 - 0901a06880112f28

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DENISOlN^i
MINES
VIA PDF AND FEDERAL EXPRESS
Denison Mines (USA) Corp,
1050 17th Street, Suite 950
Denver, CO 80265
USA
Tel: [phone]
Fax:[phone]
www.denisonmines.com
April 20, 2009
Mr. Dane L. Finerfrock
Executive Secretary
Utah Radiation Control Board
State of Utah Department of Environmental Quality
168 North 1950 West
Salt Lake City, UT 84114-4850
Re: Inspection Conducted February 24 and 25, 2009; Notice of Violation: DRM
Inspection Module IEM-01, RML UTI 900479
Dear Mr. Finerfrock:
This letter is in response to the above-referenced Notice of Violation dated March 17, 2009,
received by Denison Mines (USA) Corp. ("Denison") on March 19, 2009, which lists one
violation of the Utah Radiation Control Rules, based on an inspection of the White Mesa Mill
(the "Mill") conducted by representatives of the Utah Division of Radiation Control ("DRC") on
February 24 and 25, 2009.
The Notice of Violation requires Denison to provide a written response within 30 days after
receipt of the Notice, including:
a) Corrective actions which have been taken by Denison and the results achieved;
b) Corrective actions which will be taken to avoid further items of noncompliance; and
c) The date when full compliance will be achieved.
Specifically, the Notice of Violation states that:
"Radioactive Material License Renewal Application dated February 28, 2007,
Appendix E. Section 1.1.2, Breathing Zone Sampling, Section 1.1.2.2, Applicability,
states:
Breathing zone samples are required:
• for all calciner maintenance activities,
• at least quarterly during routine operating and maintenance fas/cs on
representative individuals performing these tasks,
• when radiation work permits are issued in which airborne concentrations
may exceed 25% of 10CFR20 lirriits,
• weekly for yellowcake operations, or
• at the discretion of the RSO.
Contrary to this requirement, no documentation for weekly breathing zone
sampling for yellowcake operations was available for review. The Radiation Safety
representatives for the licensee stated that breathing zone sampling for these
personnel is not being performed on a weekly basis as per the requirements of the
Radiation Protection Manual. The reason given was that the majority of the
yellowcake production tasks were being performed on the nightshift and that the
workers usually started work before the Radiation Safety Technicians had a
chance to issue the BZ air samplers to them."
The Notice also states that:
"The DRC encourages the licensee to exercise more attentiveness in regards to
the Personnel Monitoring Program. Although the DRC recognizes that the licensee
maintains an adequate bioassay program designed to monitor workers' internal
exposure, breathing zone air sampling for workers with the highest risk of internal
exposure is essential in determining the adequacy of the licensee's Respiratory
Protection Program."
The violation has been characterized as a Severity Level III.
Denison responds as follows:
1. Root Cause of the Noncompliance
This violation resulted from the following:
Mill Radiation Safety staff was under the mistaken and improper assumption that strict
adherence to the requirements of the Mill's Radiation Protection Manual couid be relaxed in the
circumstances, because:
• During the recent Mill run, operations in the yellowcake area were performed on a
sporadic basis, and when performed were typically of short duration. This was due to
the relatively low average grade of the ore that was fed to process and the resultant
reduced quantity of yellowcake produced. Specifically, yellowcake was typically dried
and packaged during some but not all night shifts, and the duration of the operations
typically lasted less than one hour each time. This made it difficult for Radiation Safety
staff to coordinate with the operations crew to arrange for a BZ test to be set up and
performed;
• Yellowcake operators wear PARR respirators as a matter of standard practice, with a
protection factor of 1000, thereby minimizing the risk of inhalation of yellowcake from
yellowcake operations; and
• Bioassay samples are performed every two weeks on yellowcake workers to verify that
they are not ingesting yellowcake.
Denison firmly agrees with the Executive Secretary that breathing zone air sampling for workers
with the highest risk of internal exposure (such as yellowcake workers) is essential in
determining the adequacy of the Mill's respiratory protection program. Denison also feels
strongly that requirements such as this cannot be relaxed and that Mill personnel were wrong in
making that assumption.
We have reviewed this matter carefully and have concluded that the root cause of this violation
is therefore that Mill Radiation Safety staff was wrong in believing that these requirements of the
Radiation Protection Manual could be relaxed in the circumstances.
DENISO
MINES
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2. Corrective Actions Which Have Been Taken by Denison and the Results Achieved
The following corrective actions have been taken by Denison:
a) Mill Radiation Safety staff have been advised that in no circumstances may a
monitoring requirement, or any other mandatory requirement, set out in the Radiation
Protection Manual be relaxed or waived by Radiation Safety staff unless such a
relaxation or waiver is expressly permitted by the Radiation Protection Manual;
b) Mill Radiation Safety staff have been advised that BZ samples for yellowcake
operations will be taken at the frequency required by the Radiation Protection Manual;
c) Starting February 27, 2009, Radiation Safety staff have coordinated with operations
personnel, such that operations personnel now give Radiation Safety staff advance
notice each time they intend to operate in the yellowcake drying or packaging area.
This allows Radiation Safety staff to set up BZ samples prior to commencement of
those operations and to take the samples for the short duration of those operations.
Since February 27, 2009, BZ samples have been taken in this manner on a weekly
basis for yellowcake operations; and
d) For most of these samples, test results have shown a lower limit of detection greater
than the LLD of 3 E"'^ uCi/ml required by Reg. Guide 8.30. This is because of the short
duration of the samples (typically less than one hour for each sample). However, the
measured concentrations have exceeded the reported LLD, so the fact that the reported
LLD exceeds the required LLD has not been a practical concern.
3. Corrective Actions Which Will be Taken to Avoid Further Items of Noncompliance
Mill Radiation Safety staff will continue to take weekly BZ samples for yellowcake operations in
the manner described above.
Denison is satisfied that Mill Radiation Safety staff now understand that their failure to take the
BZ samples was wrong, that they have learned from this mistake, and that they will not make
this type of mistake again.
4. Date When Full Compliance Will be Achieved.
Weekly BZs have been taken since February 27, 2009, so full compliance has been achieved
as of that date.
If you have any questions or require any further information, please contact the undersigned.
Yours truly/
DavicrC.' Frydenlund
Vice President Regulatory Affairs and Counsel
cc: Ron F. Hochstein
Harold R. Roberts
Steven D. Landau
David E. Turk
DENISO
MINES
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