Information Notice 1999-30, Failure of Double Contingency Based on Administrative Controls Involving Laboratory Sampling and Spectroscopic Analysis of Wet Uranium Waste: Difference between revisions

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{{#Wiki_filter:UNITED STATES
{{#Wiki_filter:}}
 
NUCLEAR REGULATORY COMMISSION
 
OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS
 
WASHINGTON, D.C. 20555 November 8, 1999 NRC INFORMATION NOTICE NO. 99-30: FAILURE O f DOUBLE CONTINGENCY BASED
 
ON ADMlNlSTRATlVE CONTROLS INVOLVING
 
LABORATORY SAMPLING AND
 
SPECTROSCOPIC ANALYSIS OF WET URANIUM
 
WASTE
 
==Addressees==
:
All fuel cycle licensees and certificants performing laboratory analysis to determine uranium
 
content, in support of administrative criticality safety controls.
 
==Purpose==
:
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice to alert
 
addressees to problems recently noted with the laboratory and spectroscopic analysis of
 
uranium contaminated material. Under certain conditions, incomplete dissolution of samples
 
may produce a nonconsewative laboratory result and lead to violation of criticality safety limits.
 
When the laboratory sampling is backed up by spectroscopic analysis, care must be taken to
 
ensure a sufficiently precise result through proper qualification of the spectroscopic method.
 
Recipients are expected to review this information for applicability to their facilities and consider
 
actions, as appropriate, to avoid similar problems. Suggestions contained in this information
 
notice are not NRC requirements. Therefore, no specific action nor written response is required.
 
Descri~tionof Circumstances:
On August 12, 1999, a fuel cycle licensee determined that a laboratory dissolution process was
 
not completely dissolving the uranium in certain samples, which resulted in underestimating the
 
amount of uranium in wet process waste. Subsequent licensee gamma spectroscopic analysis
 
of the wet waste also failed to detect the problem, because of inadequate spectroscopic analysis
 
conditions. Because of these simultaneous failures, excessive uranium was transferred into the
 
wet process waste storage arrays. These deficiencies in sampling and spectroscopic analysis
 
of process waste degraded the margin of safety to the extent that a criticality safety limit was
 
violated.
 
IN 99-30
                                                                            November 8, 1999 Discussion:
On July 30, 1999, a fuel cycle licensee discovered that a combustible waste bag containing
 
laboratory filter paper had higher than expected radiation readings. A subsequent licensee
 
investigation revealed that the acid leach dissolution process used to prepare samples for
 
analysis of uranium content had not completely dissolved the uranium. When the samples were
 
later filtered during the sample preparation process, some uranium was deposited on the filter
 
paper with other solids.
 
The samples in question came from a uranium recovery process that produced wet solid waste
 
that was collected into 5-gallon buckets and stored in a safe, single-layer array. The samples
 
were used to determine uranium content before the material was further collected into
 
55-galon drums. Once the waste was collected into the 55-gallon drums, the drums were
 
examined by spectroscopic analysis before being stored in a safe, triple-layer array.
 
The licensee investigation revealed that the 55-gallon drum spectroscopic analysis was also
 
assigning a low value to the uranium content of the drums. This was because the drum
 
catibration standard did not adequately resemble the material being counted and the
 
spectroscopic analysis did not account for self-shielding in the drum material.
 
The licensee had completed a criticality safety anatysis (CSA) of the tripte-layer drum storage
 
array to establish safety parameters. The analysis made use of the surface density method to
 
establish the maximum uranium content limit for individual drums. Double contingency for the
 
storage array was maintained through sampling of the 5-gallon buckets and spectroscopic
 
analysis of the 55-gallon drums. As a result of these independent and simultaneous failures, drums stored in the array exceeded the maximum allowed uranium content for single drums by
 
up to 32%, thereby causing the failure of the double-contingency arrangement. This situation
 
was safety significant in that no controls remained to limit the mass in the array, although the
 
total mass involved was far less than what would be required for a criticality.
 
An important contributing factor in this event was the limited scope of the wet waste material
 
process CSA, which stopped with the material being placed into 5-gallon buckets and did not
 
overlap the CSA covering the 55-gallon drum storage. Including the transfer from 5-gallon
 
buckets to 55-gallon drums in the wet waste material CSA should have resulted in more robust
 
controls such as a requirement for dual sampling before permitting the transfer.
 
An additional important contributing factor in this event was that the sample processing
 
procedures allowed a choice of dissolution methods under the assumption that either dissolution
 
method would produce a substantially similar result. The procedure writers mistakenly
 
assumed that the acid leach dissoiution method of sample preparation would put all uranium into
 
solution even if the entire sample was not dissolved.
 
Finally, the spectroscopic analysis procedures did not qualify waste streams for spectroscopic
 
analysis, ensure optimal packaging for spectroscopic analysis, or require corrective action, when spectroscopic analysis results did not support laboratory analysis. Spectroscopic analysis
 
IN 99-30
                                                                                  November 8, 1999 of the 55-gallon drums failed to detect the drums containing excess uranium due to these
 
failures. ANSI N15.20-1975 "Guide to Calibrating NondestructiveAssay Systems" provides a
 
more complete discussion of spectroscopic analysis sensitivities.
 
This event highlights the necessity for careful review of administrative controls, to ensure that
 
the failure of such controls is actualty unlikely. tn addition, CSAs need to be broad enough that
 
the analyst will clearly understand the safety significance of proposed controls. All procedures
 
having an impact on the control need to be reviewed carefully to ensure that the control is
 
actually implemented.
 
It is expected that addressees will evaluate the above information for applicability to licensed
 
activities. This information notice requires no specific actions nor written response. If you have
 
any questions about the information in this notice, please contact the technical contact listed
 
below or the appropriate regionai office.
 
Ap
 
ck, Dire
 
~ i v i $ o nof ~ u eCycle
 
l    Safety
 
and Safeguards
 
Office of Nuclear Material Safety
 
and Safeguards
 
===Technical Contact:===
 
===Dennis C. Morey, NMSS===
                      301-415-6107 E-mail: dcm~nrc.gov
 
Attachments:
1. List of Recently Issued MMSS Information Notices
 
2. List of Recently issued NRG Information Notices
 
Attachment I
 
IN 99-30
                                                                  November 11, 1999 LIST OF RECENTLY ISSUED
 
NMSS INFORMATION NOTICES
 
Information                                    Date of
 
Notice No.        Subject                      Issuance    Issued to
 
99-29      Authorized Contents of Spent        10128199  All power reactor licensees and
 
Fuel Casks                                    spent fuel storage licensees and
 
applicants
 
99-28      Recall of Star Brand Fire          913Oig9    Alt holders of licenses for nuclear
 
Protection Sprinkler Heads                    power, research and test reactors, and fuel cycle facilities
 
99-27      Malfunction of Source Retraction    9/2/99    All medical licensees authorized
 
Mechanism in Cobalt-60 Teletherapy            to conduct teletherapy treatments
 
Treatment Units
 
99-26      Safety and Economic                8/24/99    All Distributors andlor
 
Consequences of Misleading                    Manufacturers of Generally
 
Marketing Information                          Licensed Products
 
99-24      Broad-Scope Licensees'              7112/99    All medical licensees' of broad- Responsibilities for Reviewing and            scope and master materials
 
Approving Unregistered Sealed                  ticensees
 
Sources and Devices
 
Safety Concerns Related To                    All U.S. NRC medical licensees
 
Repeated Control Unit Failures                authorized to use brackytherapy
 
of the Nucletron Ciassic Model                sources in Nucletron Classic
 
High-Dose-Rate Remote                          Model high-dose-rate ((HDR)
            Afterloading Brachytherapy                    remote afterloaders
 
Devices
 
?O CFR 34.43(a)(I): Effective      6/25/99    Industrial Radiography Licensees
 
Date for Radiographer Certification
 
and Plans for Enforcement Discretion
 
Contingency Planning for the        6125199    All material and fuel cycle
 
Year 2000 Computer Problem                    licensees and certificate holders
 
Update on NRC's Year 2000          6114199    All material and fuel cycle
 
Activities for Materials Licensees            licensees and certificate
 
and Fuel Cycle Licensees and                  holders
 
Certificate Holders
 
Federal Bureau of Investigation's  5/28/99    A11 US. Nuclear Regulatory
 
Nuclear Site Security Program                  Commission fuel cycle, power
 
reactor, and non-power reactor
 
licensees
 
Attachment 2 IN 99-30
                                                                      November 2 I , 1999 Page 1 of l
 
LIST OF RECENTLY ISSUED
 
NRC INFORMATION NOTICES
 
Information                                          Date of
 
Notice No.            Subject                        Issuance  Issued to
 
99-29            Authorized Contents of Spent        10/28/99  All power reactor licensees and
 
Fuel Casks                                    spent fuel storage licensees and
 
applicants
 
Recall of Star Brand Fire                    All holders of licenses for nuclear
 
Protection Sprinkler Heads                    power, research, and test
 
reactors, and fuel cyde facilities
 
Malfunction of Source Retraction    9/2/99    All medical licensees authorized
 
Mechanism in Cobalt-60 Teletherapy            to conduct teletherapy treatments
 
Treatment Units
 
Safety and Economic                8/24/99  All Distributors and/or
 
Consequences of Misleading                    Manufacturers of Generally
 
Marketing Information                        Licensed Products
 
Year 2000 Contingency Planning      8/10/99  All holders of operating licenses
 
Activities                                    for nuclear power plants and fuel
 
cycle facilities
 
Broad-Scope Licensees'              7/2 2/99  All medical licensees of broad- Responsibilities for Reviewing                scope and master materials
 
and Approving Unregistered                    licensees
 
Sealed Sources and Devices
 
Safety Concerns Related To          7/6/99    All U.S. NRC medical licensees
 
Repeated Control Unit Failures                authorized to use brachytherapy
 
of the Nucletron Classic Model                sources in Nudetron Classic
 
High-Dose-Rate Remote                        Model high-dose-rate (HDR)
                Aferloading Brachytherapy                    remote afterloaders
 
Devices
 
10 CFR 34.43{a)(l); Effective      7/6/99    Industrial Radiography Licensees
 
Date for Radiographer Certification
 
and Plans for Enforcement Discretion
 
OL = Operating License
 
CP = Construction Permit
 
IN 99-30
                                                                      November 8, 1999 of the 55-gallon drums failed to detect the drums containing excess uranium due to these
 
failures. ANSI N15.20-1975 "Guide to Calibrating Nondestructive Assay Systems" provides a
 
more complete discussion of spectroscopic analysis sensitivities.
 
This event highlights the necessity for careful review of administrative controls, to ensure that
 
the failure of such controls is actually unlikely. In addition, CSAs need to be broad enough that
 
the analyst will clearly understand the safety significance of proposed controls. All procedures
 
having an impact on the control need to be reviewed carefully to ensure that the control is
 
actually implemented.
 
It is expected that addressees will evaluate the above information for applicability to licensed
 
activities. This information notice requires no specific actions nor written response. If you have
 
any questions about the information in this notice, please contact the technical contact listed
 
below or the appropriate regional office.
 
Elizabeth Q. Ten Eyck, Director
 
Division of Fuel Cycle Safety
 
and Safeguards
 
Office of Nuclear Material Safety
 
and Safeguards
 
===Technical Contact:===
 
===Dennis C. Morey, NMSS===
                      301-415-6107 E-mail: dcm@nrc.gov
 
Attachments:
1. List of Recently Issued NMSS Information Notices
 
2. List of Recently Issued NRC lnformation Notices
 
FtLE NAME: a:\99-30.in          *See ~reviousconcurrences
 
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, 1999 It is expected that addressees will evaluate the above information for applicability to licensed
 
activities. This information notice requires no specific actions nor written response. If you have
 
any questions about the information in this notice, please contact the tdchnical contact listed
 
below or the appropriate regional office.
 
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r'
                                                        Elizabeth Q. Ten            ~ ~ ~ k ,    Director
 
Division of Fuel Cyqle Safety
 
and Safeguards /
                                                        Office of Nuclear ,Material Safety
 
and safeguards
 
i
 
===Technical Contact:===
 
===Dennis C. Morey, NMSS===
                      301-475-6107                                            it
 
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1. List of Recently Issued NMSS lnformation ~ o t i c e d
 
2. List of Recently lssued NRC information Notice,$
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Revision as of 21:19, 24 September 2020

Failure of Double Contingency Based on Administrative Controls Involving Laboratory Sampling and Spectroscopic Analysis of Wet Uranium Waste
ML993060157
Person / Time
Issue date: 11/08/1999
From: Teneyck E
NRC/NMSS/FCSS
To:
Ten-Eyck E
References
IN-99-030
Download: ML993060157 (7)
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