**\[DNFSB LETTERHEAD\]**

March 10, 2005

The Honorable Samuel W. Bodman

Secretary of Energy

1000 Independence Avenue, SW

Washington, DC 20585-1000

Dear Secretary Bodman:

On March 10, 2005, the Defense Nuclear Facilities Safety Board (Board),
in accordance with 42 U.S.C. § 2286a(a)(5), unanimously approved
Recommendation 2005-1, *Nuclear Material Packaging,* which is enclosed
for your consideration. This recommendation addresses issuance of a
requirement that nuclear material packaging meet technically justified
criteria for safe storage and handling outside of engineered
contamination barriers.

After your receipt of this recommendation and as required by 42 U.S.C. §
2286d(a), the Board will promptly make it available to the public. The
Board believes that the recommendation contains no information that is
classified or otherwise restricted. To the extent this recommendation
does not include information restricted by the Department of Energy
(DOE) under the Atomic Energy Act of 1954, 42 U.S.C. §§ 2161-68, as
amended, please arrange to have it promptly placed on file in your
regional public reading rooms. The Board will also publish this
recommendation in the *Federal Register.* The Board will evaluate DOE's
response to this recommendation in accordance with Board Policy
Statement 1, *Criteria for Judging the Adequacy of DOE Responses and
Implementation Plans for Board Recommendations.*

Sincerely,

***John T. Conway***

***Chairman***

Enclosure

c: Mr. Mark B. Whitaker, Jr.

**RECOMMENDATION 2005-1 TO THE SECRETARY OF ENERGY**

**Pursuant to 42 U.S.C. § 2286a(a)(5),**

**Atomic Energy Act of 1954, As Amended**

Dated: March 10, 2005

**Background**

In Recommendation 94-1, *Improved Schedule for Remediation in the
Defense Nuclear Facilities Complex,* the Defense Nuclear Facilities
Safety Board (Board) urged the Department of Energy (DOE) to improve the
packaging and storage conditions of its large inventory of nuclear
materials once used for weapons manufacture. In particular, the Board
recommended that DOE place plutonium metals and oxides in storage
configurations meeting DOE's standard for long-term storage
(DOE-STD-3013-2004, *Stabilization, Packaging, and Storage of
Plutonium-Bearing Materials).* Some sites applied Recommendation 94-1 to
excess materials only. The Board has continued to evaluate whether other
categories of nuclear materials are stored in a safe manner.

DOE has made progress in the stabilization and storage of its excess
nuclear materials.

The storage requirements for other categories of nuclear materials,
however, are not as well defined and controlled. Specifically, DOE Order
5660.1B, *Management of Nuclear Materials,* does not address safe
storage requirements. Other than two narrowly focused
standards―DOE-STD-3013-2004 and DOE-STD-3028-2000, *Criteria for
Packaging and Storing Uranium-233-Bearing Materials―*there are no
explicit DOE-wide requirement to ensure the safe storage of nuclear
materials. Currently, the technical adequacy of packaging-the
combination of containers and other components providing a contamination
barrier-for nuclear materials, including liquids, is dependent on the
safety bases of individual facilities. Typically, facilities have
credited engineered features, such as the confinement structure and
ventilation system, for protecting offsite individuals and collocated
workers. For facility workers, however, the controls are generally
administrative, such as continuous air monitors, personal protective
equipment, periodic contamination surveys, and other aspects of the
radiological control program, in conjunction with proper evacuation
training. In accordance with DOE Standard 3009, *Preparation Guide for
U.S. Department of Energy Nonreactor Nuclear Facility Documented Safety
Analysis* (DOE-STD-3009-94, Change Notice 02), accidents that pose the
risk of significant radiological exposure to workers, such as a breached
nuclear material storage package, should be prevented or mitigated using
safety-significant controls. The preferred hierarchy of controls favors
engineered, preventive features over administrative controls.

Establishing packaging requirements for nuclear materials within the DOE
complex requires consideration of a diverse population of material types
for storage for uncertain periods of time. From a safety standpoint,
nuclear material packaging must protect against a number of challenges
that could breach the container and release radioactive material. Many
of the materials of concern generate gases that result in container
pressurization and may be pyrophoric or highly reactive. The container
design must take into account corrosion, oxidative expansion of stored
metal, effects of radiolysis, diurnal pumping and damage due to impacts
from drops and tooling during handling. The Board's recent review of
nuclear material packaging at Lawrence Livermore National Laboratory
(LLNL) revealed that many of these insults had not been fully considered
when packaging choices were made for nuclear materials not covered by
Recommendation 94-1. In fact, many of these current packaging
configurations are similar to the inadequate configurations addressed in
Recommendation 94-1, and are documented as being susceptible to eventual
failure in the report of the Recommendation 94-1 Materials
Identification and Surveillance Working Group, entitled *Summary of
Plutonium Oxide and Metal Storage Package Failures* (LA-UR-99-2896).

In general, the hazards posed by nuclear materials covered under DOE's
Implementation Plan for Recommendation 94-1 are the same as those for
nuclear materials not considered excess. When nonexcess materials are
removed from glovebox confinement for interim storage, relocation to
another work station, assay, or other purposes, the packages are
susceptible to the same types of failures as those addressed in
Recommendation 94-1. The longer the materials are stored, the greater
are the chances that the packaging will fail, especially if the
packaging has not been designed appropriately for the actual duration of
storage. The Board found that approximately 15 percent of the nonexcess
items at LLNL's Plutonium Facility are stored in packaging more than 5
years old. Some of the older items, previously declared excess, remain
in their existing packaging while awaiting stabilization and packaging
under DOE-STD-3013-2004. This situation emphasizes the need to establish
a technical basis for packaging, such as designating the time period for
which a particular container is confirmed to perform its function
adequately, in conjunction with tracking the age of containers in use.

Two recent events serve as further reminders of the importance of using
packaging that is properly designed for its function:

-   An August 5, 2003, event at Los Alamos National Laboratory's (LANL)
    Plutonium Facility resulted in multiple workers receiving
    plutonium-238 uptakes as a result of the degradation of a package
    stored longer than planned. This event is documented in a DOE Type B
    investigation report (HQ-EH-2004-1). The release of material and the
    resulting contamination and worker uptakes were due, in large part,
    to the inadequate packaging of plutonium being stored and handled
    outside of a glovebox.

-   An October 6, 2004, incident at LLNL involved the accidental drop of
    a package containing salt-bearing plutonium oxide. This event is
    documented in an Occurrence Reporting and Processing System report
    (OAK\--LLNL-LLNL-2004-0046). Although no plutonium was released,
    this event highlights the need to specify robust packaging
    requirements for materials handled outside of a glovebox.

**State of Nuclear Material Packaging**

DOE-STD-3013-2004 sets forth requirements for a robust storage
configuration for long-term storage of plutonium-bearing materials. The
requirements ensure containment through a combination of material form,
packaging design, and surveillance of containers. However, the robust,
welded configurations in the standard may not be desirable when a short
storage period is anticipated pending use of the material.

There are no equivalent requirements for interim storage. As part of its
response to Recommendation 94-1, DOE finalized guidance for the storage
of plutonium-bearing materials not packaged for long-term storage under
DOE-STD-3013. This guidance, identified in a January 25, 1996,
memorandum from Deputy Secretary of Energy Curtis entitled *Criteria for
Interim Safe Storage of Plutonium-Bearing Solid Materials,* provides a
technically justified approach to safe packaging and storage of
plutonium-bearing materials for a period of up to 20 years. Although
these Interim Safe Storage Criteria (ISSC) were not intended to apply to
materials in working inventory, much of the guidance remains germane to
storage of all nuclear materials outside of approved engineered
contamination barriers (e.g., gloveboxes or certified shipping
containers).

The ISSC were only implemented for selected excess materials and were
never formally issued as part of the DOE Directives System. In practice,
the sites use a wide variety of packages, many of which do not meet the
ISSC. According to the lessons learned from the DOE Type B investigation
of the worker uptakes at LANL, packages containing radioactive material
should be assumed unsafe until proven otherwise or the materials are
repackaged to current standards. Yet sites continue to rely on container
types that have been used historically, but have no technically
justified safety or design basis. These container types are generally
forms of packaging typically used in non-nuclear applications (e.g.,
paint cans, food pack cans). Thus, they are not designed to protect
against the hazards of the nuclear materials they contain for the
duration of storage.

Several commonly used containers and their potential inadequacies are
briefly summarized in an attachment to this Recommendation. Many other
containers are in use for specialized applications.

**Remaining Problems**

In response to the Board's May 20, 2002, correspondence on safety of
nuclear materials storage, the National Nuclear Security Administration
(NNSA) established the Inactive Actinide Working Group (IAWG), with the
goal of developing a comprehensive approach to the characterization,
packaging, and storage of a subset of nuclear materials. As presented in
a February 7, 2003, letter from NNSA to the Board, the IAWG was to meet
this goal through the development of three strategies for the following:
acceptance and retention of nuclear materials, material characterization
and storage adequacy, and disposition. The Board has been observing the
IAWG's efforts and has made three observations.

First, a key product of the IAWG effort will be the strategy for
material characterization and storage adequacy. Based on discussions
with IAWG participants, the delivery of this strategy has been delayed,
in large part because of disagreements among member sites on the
requirements necessary for justifying adequate storage. The Board
believes these requirements should provide for sufficient
characterization based on an appropriate combination of analysis and
process knowledge to determine the appropriate packaging.
Characterization information should also be used to develop a
surveillance program prioritized according to expected material and
container risk (including, for example, material type, material form,
and the age and type of container).

Second, in a June 2000 report entitled *A Strategic Approach to
Integrating the Long-Term Management of Nuclear Materials,* DOE
recognized the need to update the existing DOE Order on nuclear
materials management. In particular, this report urged improvements to
the nuclear materials management process. However, neither the current
Order nor the report explicitly considers storage safety. The Board
believes that DOE should require a technical basis for nuclear material
packaging and storage safety. Efforts to meet this requirement should
take advantage of the knowledge about storage adequacy being developed
by the IAWG, as well as existing guidance, such as the ISSC.

Third, the IAWG strategy does not include other program offices in the
defense nuclear complex, such as the Nuclear Energy, Science, and
Technology (DOE-NE) facilities involved in defense nuclear activities.
Currently, materials and activities in transition between the facilities
of different program offices have the potential to be overlooked. For
example, operators at the Savannah River Site have begun converting the
neptunium-237 solutions covered under Recommendation 94-1 to oxide and
placing the oxide in packaging intended for 1 year of storage at that
site prior to offsite shipping. The long-term storage of large
quantities of neptunium oxide has not been performed previously in the
complex, and the technical basis for ensuring the safety of such storage
is incomplete. Nonetheless, these materials will be transferred to
DOE-NE for use, where they may continue to be stored in their existing
packaging for a period of up to 20 years. In addition, the Board has
learned that DOE-NE intends to assume more direct control of activities
involving plutonium-238, which have to date been performed at NNSA
sites.

The significant radiological hazards associated with this material
necessitate appropriate storage containers for the expected storage
period. The Board believes the requirement for a technical basis for
nuclear material packaging and storage should encompass all program
offices in the defense nuclear complex. DOE may wish to consider
implementing this requirement for all program offices, including those
outside of the defense nuclear complex.

The Board is encouraged by other efforts currently under way to improve
nuclear material packaging. As a result of discussions between the
Board's staff and LLNL, the Livermore Site Office, in a December 3,
2004, letter, directed LLNL to develop a technical basis for the
adequacy of storage packages as part of a Special Nuclear Materials
Storage Plan covering "all packaging activities". LLNL replied in a
letter of January 31, 2005, outlining the required activities,
milestones, and funding to develop and implement an approved packaging
and storage program. Implementation of the plan is contingent upon the
availability of key personnel and funding. Likewise, the proposed
Documented Safety Analysis (DSA) for the LANL Plutonium Facility
requires the use of a proposed facility packaging standard and
designates material containers as a safety-related component. However,
the new DSA has been awaiting NNSA approval. In general, these efforts
represent an improvement, but they do not represent a comprehensive
DOE-wide effort, and significant differences remain in the quality of
the efforts at individual facilities.

**Recommendation**

Nuclear material packaging provides the primary containment boundary to
protect facility workers during storage and handling activities. The
Board believes the development of technically justified criteria for
packaging systems for nuclear materials is necessary on a DOE-wide
level. Therefore, the Board recommends that DOE:

Issue a requirement that nuclear material packaging meet technically
justified criteria for safe storage and handling. Packaging should, in
general, provide a robust barrier between facility workers and the
stored nuclear materials once they are removed from an approved
engineered contamination barrier. It may be appropriate to include this
requirement in an updated nuclear materials management Order.

Identify which nuclear materials should be included in the scope of the
above requirement and then determine the technically justified packaging
criteria needed to ensure the safe storage and handling of those
materials. The scope need not include waste materials, fully
encapsulated forms, or de minimus quantities such as analytical
laboratory samples. The criteria should account for the nuclear material
form and properties, expected future use, and duration of storage. It
may be appropriate for this information to be included in a packaging
Manual.

The ISSC may provide the beginning of a sound technical foundation for
developing such criteria. Although some modifications may be necessary
to make the ISSC more applicable to short-term storage, the Board
believes the basic ISSC principles―for example, the requirement for a
minimum of two contamination boundaries for high-hazard materials such
as plutonium, assurance that leak-tightness is maintained for materials
requiring a sealed environment, ability of the containers to withstand
maximum expected internal pressures, and protection against common
insults such as drops―should be maintained. The criteria should also
include provisions for surveillance programs to verify that the
container and any limited-life components are performing in a manner
consistent with the duration of storage.

Prioritize implementation of the improved nuclear material packaging
requirement consistent with the hazards of the different material types
and the risk posed by the existing package configurations and
conditions.

***John T. Conway, Chairman***

Attachment

**ATTACHMENT**

**Selection of Commonly Used Nuclear Material Packaging**

**Food-Pack Cans**

Food-pack cans are thin-walled tinned carbon steel containers used in
the food industry. No additional manufacturing or structural
requirements have been specified for application with nuclear materials.
These cans typically rely on a double-crimped metal-to-metal closure
with a thin layer of sealing compound to provide leak-tightness.
Historically, many sites have reported failures of food-pack cans.
Lawrence Livermore National Laboratory (LLNL) has reported anecdotal
evidence suggesting that none of its food-pack cans have failed to the
point of detectable contamination outside the container (UCRL-ID-11733).
However, this same report states further that some degree of oxidation
was observed in all of the examined food-pack cans containing plutonium
metal, suggesting the lack of an airtight seal. Leakage of oxygen
through nonairtight food-pack cans has been responsible for a number of
container failures reported at other sites, due to oxidative expansion
of plutonium metals (LA-UR-99-2896).

Improvements have been made to the technology, including better sealing
equipment, as discussed in a May 1984 report entitled *The Effectiveness
of Corrective Actions Taken to Preclude Events Involving Tin Cans and
Plutonium* (RHO-HS-SA-59 P). Some evidence suggests, however, that these
containers still may not be adequate for prolonged storage of nuclear
materials. Approximately half of the sampled lot of food-pack cans
sealed 10 to 14 years earlier at the Hanford Plutonium Finishing Plant
using the improved methodology failed leak testing, and nearly all
showed further indications of a potential lack of seal (LA-UR-99-3053).

Additional testing performed at Pacific Northwest National Laboratory
confirmed that the performance of food-pack cans is highly dependent on
the quality of the seal (PNL-5591). During these tests, 33
industry-standard food-pack cans were sealed according to federal
specifications. The testing revealed leak rates ranging from less than
10^-5^ cubic centimeters per second (cc/sec) to more than 2 cc/sec.
These findings should receive due consideration when food-pack cans are
used for storage applications in which a hermetic seal is required. LLNL
continues to use food-pack cans as inner and outer containers for the
storage of plutonium metal and oxide, and other sites may be storing
nuclear materials previously packaged in food-pack cans.

**Paint Cans**

Paint cans are thin-walled cans with a press-fit lid that are commonly
used to store paint.

They have been used as both inner and outer containers for the storage
of some nuclear materials, including plutonium metal. The press-fit lid
is typically placed by hand using a

mallet, which results in a questionable seal lacking any evidence of
quality control. According to a January 16, 1987, LLNL site report
entitled *Incident Analysis/Plutonium Burn in Storage Can,* oxidation
was found to be common for plutonium metal stored in paint cans
(memorandum from R. H. Condit to K. Ernst). The report goes on to
calculate that a 4 micron gap integrated across the seal area would be
sufficient to permit complete oxidation of 100 grams of plutonium metal
in 1 year. A leak of this size can reasonably be assumed to be present
in the press-fit closure; therefore, the adequacy of these cans for
nuclear material storage applications requiring a seal cannot be
ensured. Although LLNL reports that ingress of air is expected because
the lid and rim of the can are not designed to be airtight
(UCRL-ID-117333), paint cans remain approved for use for certain
applications at the laboratory. Other sites may also be storing nuclear
materials that were previously packaged in paint cans.

**Taped Slip-Lid Cans**

Slip-lid cans are thin-walled cans with a loose-fitting cover that is
often taped. While convenient and inexpensive, the use of these
containers has resulted in several breached storage packages, including
the plutonium-238 package that led to the Type B event at Los Alamos
National Laboratory (LANL). Many nuclear material packages consisting of
nested taped slip-lid cans remain at the Department of Energy's defense
nuclear facilities. By design, these cans were never intended to serve a
containment function. Furthermore, except for tape, a mechanical closure
is absent, resulting in a container that may not be able to provide even
gross retention of the materials within. The effectiveness of tape in
performing this sealing function over time and under high radiation
conditions is poorly understood. For this reason, the Interim Safe
Storage Criteria (ISSC) specifically prohibits crediting slip-lid cans
as one of the two required contamination barriers. Yet several sites
continue to use this type of packaging. For nonmetallic plutonium,
including items containing plutonium-238, LANL plans to rely on
stainless steel taped slip-lid cans only as an inner container;
currently, however, a large number of items remain at the laboratory in
nested slip-lid cans. Moreover, several varieties of slip-lid cans
continue to be approved for use as inner and outer storage containers
for certain materials at LLNL.

**Hagan Can**

LANL's Comprehensive Nuclear Material Packaging and Stabilization Plan
approves the use of a standard container known as the Hagan can, a
robust, screw-top container with an O-ring seal and filtered vent. The
Hagan can generally meet the expectations of the ISSC and has undergone
testing to certify its performance (Wickland and Mataya, PATRAM 98,
1998). However, drop testing was performed at a height lower than the
expected maximum storage height; therefore, additional analysis or
testing is required. Under the proposed Documented Safety Analysis for
LANL's Plutonium Facility, the Hagan can is classified as a
safety-significant engineered feature. The Hagan can appear to be an
appropriate outer package for nuclear material storage, although, as
recognized by LANL, the service life of the Viton (an organic
fluorocarbon compound) O-ring requires verification through a
surveillance program. Currently, Hagan cans are widely used only at
LANL; however, their use may be under consideration at other sites.

**Conflat Can**

A can fabricated with a Varian-type Conflat flange results in a
hermetically sealed, robust container that can be used to store
plutonium metal. A copper gasket on a bolted flange closure is designed
to maintain a long-term hermetic seal against oxidation of plutonium
metal. This closure type has been standard in the high-vacuum industry
for many years and has been certified to maintain a leak-tight seal
under various temperature and pressure conditions. The Conflat can is
identified in LANL's Comprehensive Nuclear Material Packaging and
Stabilization Plan as the inner container for the storage of plutonium
metal. The use of Conflat cans for storage of other nuclear materials
requiring a sealed environment may also be appropriate. Conflat cans
have been used periodically at some sites for special storage
applications, but their use is not widespread or uniform.

**Metal Drums**

Several sites commonly use U. S. Department of Transportation (DOT) Type
A containers and similar types of metal drums for overpacking of
packages of nuclear materials for onsite transportation and storage.
These containers have been certified as Type A radioactive material
packages per DOT specifications. For transportation purposes, this
certification usually is limited to a single year. The use of these
containers for interim storage beyond the certification period appears
appropriate, but consideration should be given to periodic inspection
and replacement for limited-life components, such as lid gaskets. The
*Criteria for the Safe Storage of Enriched Uranium at the Y-12 Plant*
(Y/ES-015/R2) allow interim storage of enriched uranium materials for a
period of up to 10 years in DOT Type A or Type B containers.

**Y-12 Prolonged Storage Container**

The Y-12 Y/ES-015/R2 criteria specify the use of stainless steel cans
similar to food-pack cans for prolonged low-maintenance storage for up
to 50 years. While the reliance on a single robust barrier for the
storage of enriched uranium may be appropriate, it is unclear whether
the requirement to maintain mechanical and seal integrity during normal
handling includes protection against drops. In addition, a lid sealant
compound is specified in the appendix to Y/ES-015/R2, but no discussion
of its longevity is provided. While fewer radiological hazards and less
chemical reactivity are associated with enriched uranium than with
plutonium and some other nuclear materials, further testing of these
containers would better demonstrate their reliability for long-term
storage. Currently, the Y-12 container specification is planned for use
only at the Y-12 National Security Complex.

**Plastic Bags and Bottles**

Historically, plastic bags have been relied upon to provide
contamination control for a limited period. Bag materials, which include
polyethylene, polyvinyl chloride, and related polymers, play an
important role in the overall packaging system. Their principal use is
for contamination control during the "bagout" operation, when the
nuclear material container is removed from the glovebox. Unfortunately,
some types of bags have proven to be detrimental to the integrity of
packages left in storage for prolonged periods of time. For example, the
radiation-induced degradation of polyvinyl chloride bag material led to
the production of hydrochloric acid, which in turn contributed to the
corrosion and eventual failure of containers that occurred during the
Type B event at LANL. The choice of material also impacts the generation
of radiolytic gas and effectively defines the service life of a package
when the outer container is not leak-tight. In repackaging campaigns at
LLNL, as well as at other sites, such as Hanford, bags commonly have
been found to be in a discolored or otherwise degraded state
(UCRL-ID-117333 and WHC-SD-TRP-067). While plastic bags have been in use
for a long time, little quantitative information exists on the effects
of time, temperature, and radiation field exposure on maintenance of an
effective contamination barrier. It is recognized that plastic bags may
be necessary for Contamination control, but they should not be relied
upon as a long-term contamination barrier.

In some cases, plastic bottles (e.g., safe bottles) have been used for
the storage of solutions containing nuclear materials, especially
enriched uranium, outside of processing equipment. While bottles are
constructed of thicker plastics than are bags, they undergo the same
chemical and radiolytic degradation with time and must be compatible
with the chemical properties of the contained liquids. Furthermore,
whereas bags provide only contamination control, bottles are relied upon
to provide a complete contamination barrier, including structural
integrity. Any reliance on plastic bags or plastic bottles for extended
periods of time should be informed by the available knowledge of polymer
degradation, in combination with information gleaned from surveillance
programs.