**\[DNFSB LETTERHEAD\]**

January 29, 2007

The Honorable James A. Rispoli

Assistant Secretary for Environmental Management

U.S. Department of Energy

1000 Independence Avenue, SW

Washington, DC 20585-0113

Dear Mr. Rispoli:

The staff of the Defense Nuclear Facilities Safety Board (Board) has
observed transuranic (TRU) waste dispositioning activities at Department
of Energy (DOE) sites for several years. These activities have included
characterization, packaging, and shipping TRU waste to the Waste
Isolation Pilot Plant (WIPP). In the process of these reviews, the Board
has noted a lack of a consistent approach to operational safety related
to TRU waste activities at the generator sites, prior to shipping
certified TRU waste drums to WIPP. Because of the nature of the TRU
waste activities, worker safety has been the primary concern. Los Alamos
National Laboratory is a notable exception, where public safety is also
at risk because of the proximity to the site boundary.

The Board notes that your office has issued for review the draft DOE
Standard, *Preparation of Safety Basis Documents for Transuranic (TRU)
Waste Facilities*. If comprehensively drafted and properly implemented,
this Standard should diminish the inconsistencies that currently exist.
The enclosed report summarizing several years of observations on TRU
waste operations has been prepared by the Board's staff and is provided
for your information and use. In particular, the report highlights good
practices as well as shortcomings that should be useful in the
preparation and review of the draft Standard.

Sincerely,

***A. J. Eggenberger***

***Chairman***

c: The Honorable Thomas P. D'Agostino

Mr. Mark B. Whitaker, Jr.

**DEFENSE NUCLEAR FACILITIES SAFETY BOARD**

**Staff Issue Report**

December 28, 2006

**MEMORANDUM FOR:** J. K. Fortenberry

**COPIES TO:** Board Members

**FROM:** D. Winters

**SUBJECT:** Worker Protection During Transuranic Waste Operations

The staff of the Defense Nuclear Facilities Safety Board (Board) has
been reviewing transuranic (TRU) waste activities at the Department of
Energy's (DOE) nuclear facilities for several years. The staff's reviews
have focused on proper hazard identification and analysis and the
development of appropriate controls. Because of the nature of the TRU
waste activities, worker safety has been the primary concern. Los Alamos
National Laboratory (LANL) is a notable exception, where public safety
is also at risk because of the proximity of these activities to the site
boundary. This report documents the staff's observations regarding good
practices as well as shortcomings in the handling of TRU waste drums at
the various DOE sites.

**Background.** The Waste Isolation Pilot Plant (WIPP) in New Mexico
began receiving contact-handled transuranic (CH-TRU) waste for disposal
in 1999 and has received more than 5,000 shipments to date. One major
site, the Rocky Flats Environmental Technology Site (RFETS), and several
small-quantity sites have completed shipment of all their TRU waste to
WIPP. Other sites, primarily LANL, the Hanford Site (Hanford), the
Savannah River Site (SRS), the Idaho Cleanup Project (ICP), and Oak
Ridge National Laboratory (ORNL) continue to characterize and package
CH-TRU waste and ship it to WIPP.

The primary hazards faced by workers handling TRU waste drums include
drum drops, overpressurizations, fires, and explosions. These accidents
can release the radioactive contents of the drums. Although most of the
TRU drums contain small quantities of radioactive materials (average
loadings are a few curies), nearly all drum populations contain some
drums with many hundreds of curies. In addition, a drum explosion in
close proximity to workers could cause death or serious injury.

Several fires in TRU drums have occurred around the complex and are
discussed in more detail below. A waste drum explosion occurred at the
Fernald Site in Ohio in 1991 (Occurrence Reporting and Processing System
\[ORPS\] report EM-ORO\--WMCO-FEMP-1991-0004). Although this drum
contained uranium rather than plutonium, the explosion hazard is
identical. A water-uranium reaction created hydrogen gas that collected
in the headspace of the unvented drum. This hydrogen was ignited simply
by moving the drum and causing a spark from free metal inside the drum.
Luckily, no workers were seriously injured. However, the explosion was
so loud that one worker experienced hearing loss.

The staff's reviews have focused on TRU waste retrieval,
characterization, packaging, and shipment activities and programs at
various sites across the complex. Site visits and meetings since October
2004 are listed below.

-   ORNL Waste Activities (November 2006)

-   LANL Waste Activities (August 2006)

-   TRU Waste Activities at ICP (June 2006)

-   Authorization Basis Nuclear Safety Workshop (March 2006)

-   ORNL Waste Management (February 2006)

-   National TRU Waste Program Status (January 2006)

-   Richland Operations Office Projects (January 2006)

-   New Contractors at ICP (May 2005)

-   TRU Waste Program Activities (April - May 2005)

-   TRU Waste Drum Handling, SRS (February 2005)

-   Current State of Idaho National Laboratory (February 2005)

-   Oak Ridge Environmental and Waste Management Activities (January
    2005)

-   TRU Waste Program at WIPP and LANL (January 2005)

-   TRU Waste Retrieval, SRS (November 2004)

-   WIPP and National TRU Waste Program Status (October 2004)

**CH-TRU Operations at SRS.** The legacy inventory of TRU waste at SRS
included more than 30,000 drums and 2,000 large containers. Operators at
SRS have made good progress in reducing this inventory by shipping
certified TRU waste drums to WIPP. What remains of this inventory, in
addition to newly generated TRU waste, are approximately 10,000 legacy
drums and 2,000 large containers. The early shipping campaigns at SRS
focused on low-curie drums, so the remaining drums are expected to
contain more plutonium, including more plutonium-238, and will be more
hazardous.

Prior to 2004, SRS analysts assumed that a drum deflagration accident
was not likely in an unvented TRU waste drum. This assumption was based
on the belief that in a closed TRU waste drum, oxygen is consumed as
hydrogen is generated. However, as more sites processed waste and
sampled the headspace of unvented TRU waste drums, the sampling data
clearly showed that a small but significant fraction of all unvented
drums contained hydrogen and oxygen in concentrations that would support
deflagration. Such data are well documented at Idaho (see the report
*Idaho National Engineering Laboratory Code Assessment of the Rocky
Flats Transuranic Waste*, INL-95/0281, July 1995) and SRS.

In November 2004, SRS analysts declared a positive Unreviewed Safety
Question (USQ) (see Occurrence Report SR-WSRC-SW&I-2004-0015) that
recognized the hazard posed by potential deflagrations in unvented TRU
waste drums. In response, managers at SRS implemented a new suite of
safety-related controls to protect workers from such deflagrations.
These controls were documented in a Justification for Continued
Operations applicable to the TRU waste handling activities.

Specific measures taken to protect workers included personnel exclusion
zones during drum movements, a robust blast cage for unvented drums,
drum lid restraints, long-handled tools to move workers away from the
drums, and "breathing" times for newly vented drums to allow hydrogen to
dissipate below the lower flammability limit (4 percent hydrogen by
volume). A full listing of controls for a drum deflagration is given in
Table 1, which compares the controls used at several sites. The staff
notes there is a wide disparity in the control sets used at the
different sites.

Also in 2004, SRS analysts declared another positive USQ recognizing a
similar deflagration hazard posed by the presence of volatile organic
compounds (VOCs). One prevalent source of these VOCs was found to be
solvents absorbed into rags that were included in the debris waste. Many
of the controls put in place to address the hydrogen deflagration hazard
were sufficient to prevent or mitigate the VOC deflagration hazard as
well.

The staff believes that the current control set implemented at SRS has
been appropriate and should be reviewed by other sites that process
unvented drums. The staff also understands that the Savannah River Site
is considering modifying their control set in order to accelerate the
venting of unvented drums and their subsequent disposal. These
modifications and their risk tradeoffs will be evaluated by the staff as
they are developed.

**Waste Operations at the Hanford Site.** Previous contractors at the
Hanford Site buried large quantities of TRU waste, low-level waste, and
low-level mixed waste in dozens of large burial trenches. DOE plans to
retrieve most of the TRU waste buried post-1970. To date, Hanford
operators have shipped more than 8,500 drums of TRU waste to WIPP, and
expect to ship a total of 75,000 drums by 2010. Operators are now
retrieving TRU waste from trenches that are part of the Solid Waste
Operations Complex (SWOC) in the 200-West area of Hanford.

Worker safety at the SWOC is achieved in part through the safety
management programs; safety-significant structures, systems, and
components; Technical Safety Requirement (TSR) administrative controls;
and defense-in-depth controls. For example, workers are protected from
hazards associated with TRU waste drums through identification of
potential hazardous conditions (i.e., suspect or bulging containers)
using a container management program. The SWOC safety basis relies on
the robustness of the waste container to prevent a release provided the
container passes inspection.

Worker safety is also provided by a container venting system through the
use of a nonsparking or grounded drum penetrator (typically cold
drilling) that vents the container without causing ignition. This system
is credited in the TSR as a safety-significant system. The system also
prevents uncontrolled ejection of the drum lid to protect workers from
injury and reduces the amount of radioactive material that would be
ejected from the drum. Unvented TRU drums that contain plutonium beyond
a threshold amount are placed in vented overpacks with lid and bottom
restraints, and unvented containers that cannot be overpacked because of
bulging require emergency response including emergency venting. Unvented
drums are processed through the venting system. After venting and
measurement of hydrogen concentration, drums are stored in a staging
area for a predetermined period until their hydrogen concentration
dissipates below 5 percent.

The staff notes that the hydrogen control level at Hanford is less
conservative than that used at other sites. The potential degradation of
the TRU waste drums during long periods of storage and burial introduces
a tremendous uncertainty in the drum's ability to withstand a
deflagration. Also, it is not apparent that the Hanford control level
accounts for measurement uncertainty.

The Master Documented Safety Analysis for the SWOC at Hanford states
that unvented drums are not expected to have sufficient oxygen levels to
allow combustion with any hydrogen present, and it is concluded that
drums are not expected to undergo deflagration during removal and
transfer. This conclusion is based on "no reported instances of
deflagration during handling and transport." According to the safety
analysis, DOE complex-wide data show that at levels of hydrogen greater
than 15 percent, there is generally little or no oxygen to support
deflagration. Recent experiences at ICP and the SRS contradict this
conclusion. The staff believes it is appropriate for DOE to update the
safety and technical bases to reflect the known existence of flammable
mixtures of gases in the headspace of unvented TRU waste drums.

**CH-TRU Operations at ICP.** The staff reviewed TRU waste handling
activities at the Advanced Mixed Waste Treatment Project (AMWTP) several
times in the past 2 years.

Operators at AMWTP continue to retrieve TRU waste drums from earthen
bermed above-ground storage, characterize the waste, repackage it if
necessary, and prepare packaged waste for shipment to WIPP. The AMWTP
still contains more than 30,000 TRU waste drums and boxes, most of which
are unvented and a portion of which are deteriorated. Some of these TRU
drums are known to generate hydrogen gas. Hydrogen and oxygen have been
measured in flammable concentrations in the headspace of TRU drums, and
a TRU drum fire occurred at AMWTP in 2003 (ORPS report
EM-ID-BNFL-AMWTP-2005-0008).

Drum deflagrations and fires are recognized as anticipated events in
safety basis for the AMWTP. The accident analysis concludes that the
deflagration accident does not result in consequences that exceed
evaluation guidelines for dose to the public, so no safety-class
controls are required. Furthermore, the accident analysis concludes that
worker risks are low, so no safety-significant controls or specific
administrative controls (SACs) are required. The staff does not agree
with this conclusion. The staff believes there is the potential for
"serious injury" or "significant radiological exposure" from a drum
deflagration accident. According to DOE Standard DOE-STD-3009,
*Guidelines for the Preparation of Nuclear Facility Documented Safety
Analyses*, such consequences require that "safety-significant" controls
should be considered.

After another TRU drum fire occurred at Idaho's Accelerated Retrieval
Project in 2005 (ORPS Report EM-ID-CWI-RWMC-2005-0012), managers at the
AMWTP implemented new process controls, including LEXAN^®^ shields
between workers and drums, long-handled tools to move workers away from
drums, and drum lid restraining devices for bulged drums (see Table 1).
Although these controls added some protection, they were simply process
controls, not formal, and were not reviewed and approved by DOE.
Furthermore, the staff noted that operators at ICP, unlike operators at
other sites, were not measuring hydrogen, oxygen, or VOCs in unvented
drums-information essential to analyzing the hazard faced by the
workers. The staff discussed these issues with representatives of DOE
Idaho Operation Office and the contractor, who agreed verbally to
consider formalizing the controls in some manner, such as through the
use of SACs.

**CH-TRU Waste Operations at LANL.** Operators at LANL have been
shipping TRU waste drums to WIPP for several years. However, the pace of
shipments has been slow, and the total inventory of TRU waste at LANL
has not changed appreciably. The waste areas at LANL (primarily
Technical Area-54) still store more than 20,000 containers holding
approximately 120,000 curies of TRU waste.

At LANL, all TRU waste drums retrieved from underground have been
vented, with a few exceptions. Most drums are also in reasonably good
condition and are required by the LANL authorization basis to provide a
safety-class confinement function. Most drums are stored on pallets and
secured by steel banding to prevent drops that may breach the drums. In
general, the staff believes that the procedures and controls to prevent
drum drops and drum deflagrations are adequate to protect the workers.

The authorization bases for TRU waste facilities at LANL note that the
most significant public risk is driven by fires caused by seismic events
and airplane crashes. Because of the source term in the TRU waste and
the proximity of the waste to the site boundary, these fire scenarios
result in dose consequences that far exceed evaluation guidelines for
dose to the public. Therefore, the authorization bases call for the
implementation of several safety-class controls. Operators at LANL have
implemented these controls with varying degrees of success.

At LANL, the most effective method of reducing risks to the public and
workers posed by the TRU waste is to reduce the TRU waste source term.
The staff believes it would be prudent for DOE to remove TRU waste from
LANL in the most expeditious manner consistent with safe operations.

**CH-TRU Operations at ORNL.** At ORNL, CH-TRU waste is stored primarily
in approximately 3,500 drums located in several steel buildings known as
the Melton Valley Solid Waste Storage Facilities. In previous years,
operators transferred liquid waste, vented drums, and other TRU waste
containers to the TRU/Alpha Low Level Waste Processing Facility nearby
to be processed and prepared for shipment to WIPP. However, most of the
remaining drums in storage are unvented and are required to be vented
prior to movement.

The staff has reviewed the ORNL TRU waste operations several times in
the past two years, and found a reasonably conservative approach in
providing for worker protection. Because the drum venting capability at
ORNL was just established in 2006, the development of this capability
benefited from many of the lessons learned at other DOE sites.

The handling of unvented drums and the drum venting process are
accompanied by a reasonable suite of safety controls that serve to
provide adequate protection to the workers. For example, in recognition
of the hydrogen deflagration hazard, operators are required to measure
hydrogen, oxygen, and VOCs in unvented drums as the drums are vented.
This activity takes place in an enclosed, remotely-operated trailer. If
operators find the hydrogen concentration to be greater than 3.6
percent, then they are required to purge the drum with inert gas until
the hydrogen level is reduced to approximately 1 percent. The drum is
then staged and allowed to breathe for as long as 45 days. The hydrogen
control level of 3.6 percent is based on applying a 10 percent
instrument uncertainty to the lower flammability limit of 4 percent. All
controls for a potential drum deflagration are listed in Table 1. The
staff believes the controls implemented at ORNL are appropriate and
adequate.

**Consistency in TRU Waste Activities.** In March 2006, DOE managers
established a TRU waste authorization bases workshop and have held
several working group meetings since then. DOE also sponsors a TRU Waste
Corporate Board that provides direction on complex-wide TRU waste
issues. The Board's staff attended many of these meetings and provided
informal feedback to DOE on a real-time basis. The DOE efforts have a
goal of establishing a consistent process for developing authorization
basis documents for TRU waste activities. The staff believes that the
observations presented in this report can be useful to DOE in their
efforts.

In order to address safety issues related to TRU waste activities and to
achieve consistency, DOE managers drafted a new DOE standard in the Fall
of 2006. The Standard, Preparation of Safety Basis Documents for
Transuranic (TR U) Waste Activities, entered the review and comment
process in late November 2006. The Board's staff is reviewing and will
provide comments separately on this standard.

**Table 1. Comparison of Controls for Deflagration of Unvented
Drums^+^**

<table>
<colgroup>
<col style="width: 11%" />
<col style="width: 9%" />
<col style="width: 7%" />
<col style="width: 6%" />
<col style="width: 6%" />
<col style="width: 5%" />
<col style="width: 17%" />
<col style="width: 16%" />
<col style="width: 6%" />
<col style="width: 12%" />
</colgroup>
<tbody>
<tr class="odd">
<td><strong>Location</strong></td>
<td><strong>Material at Risk</strong></td>
<td><strong>Frequency</strong></td>
<td colspan="3"><strong>Unmitigated Consequence</strong></td>
<td><strong>Safety Significant Controls</strong></td>
<td><strong>Other Contols</strong></td>
<td><strong>H2 Control</strong></td>
<td><strong>Comments</strong></td>
</tr>
<tr class="even">
<td></td>
<td>Pu-239 Equiv Ci</td>
<td></td>
<td>Worker</td>
<td>Onsite</td>
<td>Offsite</td>
<td></td>
<td></td>
<td>vol%</td>
<td></td>
</tr>
<tr class="odd">
<td>ORNL – Melton Valley Solid Waste Storage Facilities</td>
<td>392 (1 max loaded drum)</td>
<td>Anticipated</td>
<td>High</td>
<td>High</td>
<td>Low</td>
<td><ul>
<li><p>Non-sparking Drum Penetrator Tip</p></li>
<li><p>Drum Purging System</p></li>
<li><p>Drum Vent</p></li>
<li><p>Grounding Mat</p></li>
<li><p>Spill Pallet - *</p></li>
<li><p>HEPA Filter</p></li>
<li><p>Portable Unit</p></li>
<li><p>Drum Handling Equipment</p></li>
<li><p>Lid Restraint - *</p></li>
</ul></td>
<td><ul>
<li><p>Procedures and Training - #</p></li>
<li><p>Movement Restrictions - *</p></li>
</ul></td>
<td>3.6</td>
<td></td>
</tr>
<tr class="even">
<td rowspan="2">INL – Advanced Mixed Waste Treatment Project</td>
<td>154.6 (1 max loaded drum)</td>
<td>Extremely Unlikely</td>
<td>Not evaluated: No personnel in venting structure</td>
<td><p>Low</p>
<p>16 rem</p></td>
<td><p>Low</p>
<p>0.55 rem</p></td>
<td rowspan="2"><ul>
<li><p>None</p></li>
</ul></td>
<td rowspan="2"><ul>
<li><p>Procedures and Training - #</p></li>
<li><p>Movement Restrictions</p></li>
<li><p>Remote Penetration in Venting Enclosure - *</p></li>
<li><p>Industrial Hygiene Program</p></li>
<li><p>Conduct of Operations</p></li>
<li><p>Procedures of Training</p></li>
<li><p>Ignition Source Control</p></li>
<li><p>Fire Suppression - #</p></li>
<li><p>Maintenance - #</p></li>
<li><p>Radiation Protection Program - #</p></li>
<li><p>Personal Protective Equipment</p></li>
<li><p>Emergency Preparation</p></li>
</ul></td>
<td rowspan="2">Not measured</td>
<td rowspan="2">Inconsistent use of frequencies/consequences</td>
</tr>
<tr class="odd">
<td>Average drum</td>
<td>Unlikely</td>
<td><p>Low</p>
<p>11 rem</p></td>
<td><p>Low</p>
<p>0.35 rem</p></td>
<td><p>Low</p>
<p>0.013 rem</p></td>
</tr>
<tr class="even">
<td>SRS – Solid Waste Management Facility</td>
<td>1170 several drums involved in deflagration</td>
<td>Anticipated</td>
<td>Moderate</td>
<td><p>Moderate</p>
<p>49 rem</p></td>
<td><p>Low</p>
<p>0.1 rem</p></td>
<td><ul>
<li><p>Drum Venting System Cabinet</p></li>
<li><p>DVS Filtration Ductwork</p></li>
<li><p>DVS Blast Shield</p></li>
<li><p>Forklift Design - &amp;</p></li>
<li><p>Engineered Transport Box - &amp;</p></li>
<li><p>Hoist Shield - &amp;</p></li>
</ul></td>
<td><ul>
<li><p>Nitrogen Inerting</p></li>
<li><p>Procedures and Training - #</p></li>
<li><p>Emergency Preparation - #</p></li>
<li><p>Fire Response - #</p></li>
<li><p>Slow Drill Speeds</p></li>
<li><p>Vehicle Restrictions - &amp;</p></li>
<li><p>Personnel Restrictions - &amp;</p></li>
<li><p>Standoff Distances - &amp;</p></li>
</ul></td>
<td>4.0</td>
<td></td>
</tr>
<tr class="odd">
<td>Hanford – Solid Waste Operations Complex</td>
<td>82.5 (1 drum) This is not a max but is justified as conservative as
drums with higher TRU tend to have multiple containments or stable
matrices</td>
<td>Anticipated</td>
<td>High or Moderate such that controls are required for worker
protection</td>
<td>Moderate</td>
<td><p>Low</p>
<p>0.057 rem</p></td>
<td><p>Drum Venting System – Three Types</p>
<p>Type 1</p>
<ul>
<li><p>Cold Drilling</p></li>
<li><p>Grounding/Bonding</p></li>
<li><p>Confinement/Distance</p></li>
</ul>
<p>Type 2</p>
<ul>
<li><p>Non-Sparking Penetrator</p></li>
<li><p>Lid Restraint or Physical Barrier</p></li>
<li><p>Distance/Shielding</p></li>
</ul>
<p>Type 3</p>
<ul>
<li><p>Cold Drilling</p></li>
<li><p>Grounding/Bonding</p></li>
<li><p>Lid Restraint</p></li>
<li><p>Remote Activation/Distance</p></li>
</ul></td>
<td><ul>
<li><p>Vented overpacks may be used for drums with &gt;33 PE-Ci</p></li>
</ul></td>
<td>5.0</td>
<td>Additional admin controls required for certain higher risk
drums</td>
</tr>
<tr class="even">
<td>LANL TA-54 Area G</td>
<td>300</td>
<td>Beyond Extremely unlikely</td>
<td></td>
<td></td>
<td><p>High</p>
<p>30 rem</p></td>
<td><ul>
<li><p>TRU Waste Container (Safety Class)</p></li>
</ul></td>
<td><ul>
<li><p>Installed and Inspected Vents</p></li>
<li><p>Overpacks</p></li>
</ul></td>
<td>N/A</td>
<td>All drums either already vented or overpacked at LANL</td>
</tr>
</tbody>
</table>

\+ - Deflagration accident used as one example. Each facility evaluates
all credible accidents.

\* - Specific Administrative Control in TSRs

\# - Other TSR Administrative Control

& - Additional Justification for Continued Operations Controls (SRS
Only)

References for Table 1.

**ORNL**

**Documented Safety Analysis (DSA):** *Documented Safety Analysis for
the Melton Valley Solid Waste Storage Facilities*, DSA-OR-MVSWSF-0019,
Rev. 8A, January 2006

**Technical Safety Requirements (TSR):** *Technical Safety Requirements
for the Melton Valley Solid Waste Storage Facilities*,
TSR-OR-MVSWSF-0018, Rev. 8B, February 2006

**INL**

**DSA:** Idaho National Laboratory Advanced Mixed Waste Treatment
Project Documented Safety Analysis, AMWTP-RPT-DSA-02, DRAFT Rev. 4, June
2006

**TSR:** Technical Safety Requirements Advanced Mixed Waste Treatment
Project, AMWTP-RPT-ESH-03, DRAFT Rev. 6, June 2006

**SRS**

**Safety Analysis Report (SAR):** *Savannah River Site Solid Waste
Management Facility Safety Analysis Report*, WSRC-SA-22, Rev. 5, January
2005

**TSR:** *Technical Safety Requirements Savannah River Site Solid Waste
Management Facility*, WSRC-TS-65-19, Rev. 9, October 2005

**Justification for Continued Operations (JCO):** *Solid Waste
Management facility Handling and Processing of Flammable Containers on
SWMF TRU Waste Pads*; *Justification for Continued Operation*,
WSRC-TR-2004-00618, Rev. 9, September 2006

**Hanford**

**DSA:** *Master Documented Safety Analysis for the Solid Waste
Operations Complex*, HNF-14741, Rev. 2A, April 2005

**TSR:** *Technical Safety Requirements for the Solid Waste Operations
Complex*, HNF-15280, Rev. 2A, April 2005

**LANL**

**DSA:** *TA-54 Area G Documented Safety Analysis*, ABD-WFM-001, Rev. 0,
April 2003

**TSR:** *Technical Safety Requirements for the Technical Area 54, Area
G*, ABD-WFM-002, Rev. 0, April 2003