[DNFSB
LETTERHEAD]
May 1, 2006
Mr. C. Russell H. Shearer
Acting Assistant Secretary for
Environment, Safety and Health
U.S. Department of Energy
1000 Independence Avenue, SW
Washington, DC 20585-1000
Dear Mr. Shearer:
The Defense Nuclear Facilities
Safety Board (Board) received the Department of Energy’s (DOE) letter dated
March 30, 2006, transmitting the draft DOE manual Nuclear
Material
Packaging Manual.
This manual is a deliverable under the Implementation Plan
for the Board’s Recommendation 2005-1, Nuclear Material Packaging. As was the case with comments from DOE’s technical review
board on the draft repackaging prioritization methodology, DOE’s internal
process for comment resolution failed to adequately resolve all substantive
comments. Detailed comments developed by
the Board’s staff on the draft packaging manual are provided in the enclosure
to this letter. These comments were also
provided to DOE’s Responsible Manager for Recommendation 2005-1 on April 21, 2006. Pursuant to 42 U.S.C. § 2286b(d),
the Board requests that, within 30 days of receipt of this letter, DOE provide
a response to the enclosed comments. This response should provide a specific resolution
for each comment that either accepts the comment, with proposed changes to the
draft manual, or rejects the comment, with justification based on technical
merit and impact on safety.
In the Implementation Plan, DOE
committed to developing a nuclear material packaging manual in response to two
sub-recommendations: (1) “Issue a
requirement that nuclear material packaging meet technically justified criteria
for safe storage and handling”; and (2) “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 Implementation
Plan lists baseline assumptions that are consistent with these
sub-recommendations: “This plan deals
with materials that are stored outside of an approved engineered contamination
confinement barrier, such as a glovebox or packages meeting DOE-STD-3013 and/or
DOE-STD-3028”; and “This plan deals with solid and liquid nuclear materials in
interim storage.” The draft manual
appropriately defines interim storage as follows: “Interim Storage is on-site storage of
materials outside of an approved engineered contamination barrier. Interim storage excludes materials that are
stored in accordance with DOE-STD-3013, DOE-STD-3028, or DOE-HDBK-1129.” Defining
the scope of the nuclear material packaging manual using these assumptions and
the associated definition would have met the intent of Recommendation 2005-1.
The Board has reviewed the draft
packaging manual. In general, the manual
sets forth a
sound approach
to nuclear material packaging. However,
it contains an exclusion for packages in a
“specifically analyzed and controlled radiological production or processing
activity.” This exclusion significantly
departs from the intent of the Recommendation and the Implementation Plan, and
could exclude from the scope of the manual nuclear materials in any facility
operating under the requirements of either 10 Code of Federal Regulations (CFR)
835, Occupational
Radiation Protection, or
10 CFR 830, Nuclear
Safety Management. Retaining this exclusion could
greatly reduce the safety benefits of the manual’s entire content.
DOE’s technical review board for
Recommendation 2005-1 commented on this serious deficiency before the draft
manual was sent to the Board. However,
DOE failed to adequately resolve this substantive comment. In its acceptance of the Implementation Plan
for Recommendation 2005-1, the Board noted that it was encouraged by DOE’s establishment
of a technical review board to comment on the packaging requirements document
and the repackaging prioritization methodology. In failing to correct deficiencies identified
by the technical review board, however, DOE is undermining the benefits of
having an independent peer review process.
Sincerely,
A.
J. Eggenberger
Chairman
c: Mr. Mark B. Whitaker, Jr.
Mr. Richard
M. Stark
Enclosure
Enclosure
Comments
of the Board’s Staff on Draft
DOE
Manual M441.1, Nuclear
Material Packaging Manual
1. The scope exclusion for
nuclear materials in a “specifically analyzed and controlled radiological
production or processing activity” is inconsistent with DOE’s Implementation
Plan (IP). Under this broad definition,
activities involving nuclear materials in any facility operating under the
requirements of either 10 CFR 835, Occupational Radiation Protection, or 10 CFR 830, Nuclear Safety
Management, could
potentially be excluded from the manual requirements. The Board’s staff understands the intent is
not to overly constrain “in-process” activities. However, this exclusion appears to be
inconsistent with a baseline assumption in the IP, which states, “This plan
deals with materials that are stored outside of an approved engineered
contamination confinement barrier, such as a glovebox or packages meeting
DOE-STD-3013 and/or DOE-STD-3028.” This
exclusion also appears to be inconsistent with the manual’s definition of
interim storage, which states, “Interim Storage is on-site storage of materials
outside of an approved engineered contamination barrier. Interim storage excludes materials that are
stored in accordance with DOE-STD-3013, DOE-STD-3028, or DOE-HDBK-1129.” A more defensible approach, consistent with the intent of
Recommendation 2005-1, would be to rely on a reasonable time limit to allow for
certain processes between removal of nuclear materials from an engineered
contamination barrier and placement in packaging that meets the requirements of
the manual.
2. The options for calculating
material thresholds have significantly different technical and regulatory
origins and result in substantially different values. No justification is provided for allowing field activities
to choose between the two methodologies, which in some cases may result in
differences in threshold quantity of several orders of magnitude for identical
materials. This inconsistency could
result in excluding packages with sufficient quantities of material to be
within the scope of the manual, or in categorizing materials as low risk that
would otherwise be high risk, depending on which
methodology is used. The manual ought to
provide consistent protection of workers from equivalent quantities of nuclear
material.
The
methodology derived from DOE-HDBK-3010, Airborne Release Fractions/Rates and Respirable
Fractions for Nonreactor
Nuclear Facilities, employs
a dilution factor in the calculation, and does not appear to have been reviewed
previously or approved for use in safety basis calculations for determination
of controls to protect facility workers. Such a calculation is inconsistent with the
requirements in DOE-STD-3009 CN2, Preparation Guide for U.S. Department of Energy
Nonreactor Nuclear Facility Documented Safety Analyses, which emphasize the difficulty
of developing conservative quantitative consequences to facility workers. The methodology derived from DOE-HDBK-3010
requires significant knowledge of the nuclear material’s physical
characteristics (e.g., particle size distribution), which are not commonly
determined under current practices. Assuming adequate information is available, the methodology then requires difficult technical
judgments to ascertain appropriate values for respirable release fractions from
DOE-HDBK-3010. The values listed in
DOE-HDBK-3010 were developed experimentally for estimating macro source terms
resulting from significant facility accidents (e.g., facility fires); those
source terms were to be included in airborne plume models used to determine
consequences for receptors located at relatively large distances from the
facility. The use of these values in conjunction
with a dilution factor for calculating consequences impacting safety to workers
in the immediate vicinity of a radioactive material release from a package is
highly questionable. The drawbacks of
using this methodology to calculate threshold material quantities for the
packaging manual are exacerbated by the lack of an explicit mechanism for review
and approval by subject matter experts to provide a level of consistency across
sites.
The
methodology derived from DOE-HDBK-3010 contrasts with the technical simplicity
and regulatory precedence associated with the more conservative methodology
based on net intake factor used to calculate the A2 values specified in 49 CFR
173.435, Shippers―General Requirements for
Shipments and Packagings. The A2 values have long been accepted as adequately
conservative by numerous regulatory bodies, including the U.S. Department of
Transportation, the U.S. Nuclear Regulatory Commission, and the International
Atomic Energy Agency. The A2
methodology, as applied in the manual, offers a simple, defensible way to
determine material thresholds for facility workers by adjusting dose
consequences to account for the receptor differences between a nuclear facility
worker and a member of the public (e.g., shipping courier or first responder). The methodology derived from DOE-HDBK-3010
ought to be dropped in favor of the A2 methodology.
3. The manual lacks technical
bases for key parameters specified for several significant requirements. While many of the values appear to lead to reasonable
results, providing technical bases for key parameters that are specified as
requirements would strengthen the overall credibility of the document. Examples of key parameters that ought to be
supported with a technical basis include the following:
4. The list of radionuclides
covered by the manual appears to be incomplete. A significant number of radionuclides that may fall under
the definition of “by-product material” and whose dominant dose contributions
are through the inhalation pathway are not included in Table 1.1, and therefore
would be excluded from the manual requirements. It is unclear whether some of these isotopes
are currently present in the complex or may be separated in the future. Given this possibility and the hazardous
nature of these radionuclides, it would be more appropriate to specify an
overall methodology for identification of in-scope radionuclides, and present
the Table 1.1 as a listing of radionuclides commonly found in the complex.
5. The definition of a “sealed
source” requires further clarification to qualify for exclusion from the scope
of the manual. Exclusion of sealed sources is
consistent with Recommendation 2005-1; however,
the Board’s expectation was that all excluded nuclear materials would be
packaged or protected in a manner that would afford protection to workers
substantially equivalent to that provided by packaging meeting the requirements
in the manual. Indeed, this is why
materials packaged to meet DOE-STD-3013 or DOE-STD-3028 are
excluded from the scope of the manual. The definition referenced in 10 CFR 835.2 does
not provide adequate criteria to ensure this protection; thus there is a need
for greater specificity in the definition (e.g., minimum classification levels
under American National Standards Institute [ANSI] N43.6, Sealed Radioactive Sources―Classification,
or similar basis).
6. The surveillance techniques
required to be considered may result in inconsistent or inadequate detection of
vulnerable packages. The overall objective of
providing early indications of container degradation is appropriate. However, implementation of the surveillance
techniques listed for consideration does not appear to be required. The result could be significantly different
levels of rigor applied in determining the state of the packaging depending on
which techniques the sites implement. Greater specificity in either the performance
of the objective or the required use of techniques may be necessary to ensure
that sites perform adequate surveillance.
7. Information on the
technical basis for packaging and surveillance is not explicitly required in
Section 1.4, Documentation.
Although this information is generally specified as a requirement
under the Packaging
Criteria sections,
it is unclear where this information would be documented for review. Stipulating a complete list of documentation
requirements for a centralized technical basis document for packaging and
surveillance would assist the field element managers in their review and
approval process.
8. DOE’s review process for
Recommendation 2005-1 deliverables requires improvement. As was the case with the draft repackaging prioritization
methodology, many of the substantive technical issues concerning the manual
that were identified by the Board’s staff were also identified by DOE’s
technical review board (TRB). Some of
the TRB’s comments do not appear to have received the appropriate level of
consideration and technical resolution. For example, significant comments generated by
several TRB members pertaining to the problems outlined in the staffs comments
1-3 above resulted in only trivial changes in the wording of the manual. In its acceptance of the IP, the Board noted
it was encouraged by DOE’s decision to use a TRB to review and comment on the
principal activities related to the resolution of safety issues. Unfortunately, DOE has failed to incorporate
substantive changes to both the draft manual and the draft repackaging prioritization
methodology required to adequately resolve significant comments made by the TRB.
A mechanism for consistently developing
balanced, technically valid responses to the TRB’s comments is needed.