[Federal Register Volume 76, Number 124 (Tuesday, June 28, 2011)]
[Notices]
[Pages 37798-37799]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-16138]
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DEPARTMENT OF ENERGY
DOE Response to Recommendation 2010-2 of the Defense Nuclear
Facilities Safety Board, Pulse Jet Mixing at the Waste Treatment and
Immobilization Plant
AGENCY: Department of Energy.
ACTION: Notice.
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SUMMARY: On May 20, 2011, the Defense Nuclear Facilities Safety Board
reaffirmed their Recommendation 2010-2, concerning Pulse Jet Mixing at
the Waste Treatment and Immobilization Plant, to the Department of
Energy. In accordance with section 315(b) of the Atomic Energy Act of
1954, as amended, 42 U.S.C. 2286d(d), The following represents the
Secretary of Energy's final decision on the recommendation and the
reasoning for his decision.
ADDRESSES: Send comments, data, views, or arguments concerning the
Secretary's response to: Defense Nuclear Facilities Safety Board, 625
Indiana Avenue, NW., Suite 700, Washington, DC 20004.
FOR FURTHER INFORMATION CONTACT: Mr. Steven Petras, Nuclear Engineer,
Departmental Representative to the Defense Nuclear Facilities Safety
Board, Office of Health, Safety and Security, U.S. Department of
Energy, 1000 Independence Avenue, SW., Washington, DC 20585.
Issued in Washington, DC on June 20, 2011.
Mari-Josette Campagnone,
Departmental Representative to the Defense Nuclear Facilities Safety
Board, Office of Health, Safety and Security.
June 20, 2011
The Honorable Peter S. Winokur,
Chairman,
Defense Nuclear Facilities Safety Board,
625 Indiana Avenue, NW, Suite 700,
Washington, DC 20004-2901.
Dear Mr. Chairman:
This letter responds to your May 20, 2011, letter which
reaffirmed the Defense Nuclear Facilities Safety Board (Board)
Recommendation 2010-2, Pulse Jet Mixing (PJM) at the Waste Treatment
and Immobilization Plant (WTP).
Your reaffirmation letter interpreted the Department of Energy's
(DOE) February 10, 2011, response to Recommendation 2010-2 as a
rejection of sub-recommendations 3 and 4. The intent of our response
was not to reject any of the sub-recommendations, but to clarify the
actions being taken to validate the design, operation, and safety of
the WTP PJM and transfer systems.
Our response explained that we agreed with both the intent of
your Recommendation and that more testing and analyses should be
conducted to provide additional confidence that the WTP PJM and
transfer systems will achieve design and operating requirements.
Since then, we have worked closely to ensure a mutual understanding
of your Recommendation. The enclosure to this letter documents the
significant progress we have collectively made in achieving the
necessary clarification and a path forward for implementing your
Recommendation. DOE is encouraged by the level of clarity achieved
to date, and confident we have established the foundational premises
needed to bring each of the remaining issues to closure, using the
Implementation Plan (IP) as the vehicle for documenting a final
technical approach that can be mutually endorsed.
This clarification serves to restate my decision to accept your
Recommendation 2010-02. We believe our IP will meet the underlying
safety improvement objectives of your Recommendation. Pursuant to 42
U.S.C. Sec. 2286e, an IP for this Recommendation will be prepared
and delivered to the Board no later than 90 days after publication
of this response in the Federal Register.
We look forward to further working with the Board and your staff
to reach final closure on the intent and scope of deliverables while
maintaining our obligations to address Hanford's environmental
liabilities. We are confident that the IP for Recommendation 2010-2
is being developed, such that the WTP Project completes its design
and construction activities with full assurance of nuclear safety
for the life of WTP operations.
Mr. Dale Knutson is the responsible manager for Recommendation
2010-02. If you have any further questions, please contact me or Dr.
In[eacute]s R. Triay, Assistant Secretary for Environmental
Management, at (202) 586-7709.
Sincerely,
Steven Chu
Enclosure
Enclosure to 2010-2 Reaffirmation Response
DOE has taken, and continues to take, steps to increase confidence
that the pulse jet-mixed vessels will comply with operating
requirements. Your reaffirmation letter highlights several primary
elements of the Recommendation, and we believe our shared concerns
regarding pulse jet mixing at the Waste Treatment Plant (WTP) will be
adequately addressed by the Department of Energy's (DOE) current
direction related to resolving pulse jet mixing and transfer system
uncertainty. The project will rely on preventing nuclear criticality
safety hazards by establishing and implementing waste acceptance
criteria (WAC) for any waste transferred to WTP. A large scale test
program will be used to determine the performance limits of the mixing,
sampling, and transfer systems and its results will be used to confirm
the WAC are implemented with due consideration for uncertainties and
margins.
Significant progress has been made on achieving the clarifications
needed to further develop, and ultimately complete the implementation
plan for Defense Nuclear Facilities Safety Board's (Board)
Recommendation 2010-2. The Board's May 20, 2011, letter which
reaffirmed the Defense Nuclear Facilities Safety Board Recommendation
2010-2, Pulse Jet Mixing at the Waste Treatment and Immobilization
Plant, identified the following residual concerns; progress in
achieving clarification on each of those concerns is provided:
Testing must be done at the proper scale to demonstrate
the limits of
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performance of the vessel mixing and transfer systems.
WTP will perform the first Large Scale Integrated Tests (LSIT) at
4, 8 and 14-foot scale. The project has identified commercially
available vessels to support this increment of testing. If test results
indicate a larger scale test than the 14-foot vessel is beneficial, a
decision point will be included in the implementation plan to determine
the scope and benefit of testing at a larger scale. A full technical
justification will be provided that will support our decision.
These tests must be conducted using appropriate waste
simulants with properties that conservatively envelope the properties
of the high-level wastes stored in Hanford's tank farms.
WTP has issued a charter and formed a panel of subject matter
experts to review and advise on all aspects of large-scale mixing
including the simulants to be used for LSIT that address the physical
parameters of testing and represent known properties of tank waste.
There are concerns with selection of simulants which include
manufacture, use and disposal of large volumes of potentially very
hazardous simulant materials that would require a significant waste
disposal effort of its own; and potentially prohibitive cost for
manufacture and disposal of simulants. It is understood these
considerations represent tradeoffs, but the goal is to ultimately not
undermine the representative accuracy of the simulants required for
testing.
Testing must demonstrate that pulse-jet mixed vessels can
be adequately operated using prototypic equipment (e.g., control
systems) during multi-batch operations.
DOE has approved an additional scope of work to release the
contractor to initiate design, procurement and perform ``informational
testing'' activities that will be the predecessor to the more
formalized testing; conducted in accordance with NQA-1 requirements, to
support design confirmation.
The heel removal and cleanout systems must be designed and
tested as early as practicable, the performance limits for these
systems established, and the limits of their operation factored into
the development of the WAC and the operating envelope of WTP.
Components of large scale testing that will result in a better
understanding of mixing characteristics such as bottom motion, zones of
influence and partial particle separation will be performed early
within the testing program to better define what is required for heel
removal and cleanout system designs. The project then intends to test
heel removal and cleanout very early in the testing phase and in every
scale of LSIT in order to inform design decisions for process vessels.
The Board considers that DOE has rejected sub-
Recommendation 3 associated with the use of large scale tests to verify
and validate computational fluid dynamic (CFD) models of full-scale WTP
mixing systems * * * the Board believes that obtaining data from near
full-scale tests is necessary to establish within a reasonable range of
uncertainty, that the WTP's CFD model is an accurate representation of
the full scale mixing systems.
DOE agrees that it is necessary that the CFD model adequately
represent full-scale mixing systems, but has not yet concluded that
data from future near-full-scale tests is necessary to complete model
verification and validation (V&V). DOE is in the process of determining
if existing data sets are sufficient to complete V&V requirements of
the CFD model for pulse jet-mixed vessels in accordance with the ASME
V&V 20-2009, Standard for Verification and Validation in Computational
Fluid Dynamics and Heat Transfer. The DOE review is ongoing, including
evaluation by subject matter experts from the National Energy
Technology Laboratory. If necessary, additional data sets, that may
include the upcoming near-full-scale tests, will be collected to
support the V&V.
The Board also considers that DOE has rejected sub-
recommendation 4 associated with the capability of WTP and tank farms
to obtain representative samples. The DNFSB also stated that: Testing
must demonstrate that representative samples can be taken from waste
feed delivery tanks to meet the Waste Acceptance Criteria (WAC), and
from WTP process vessels to meet safety related operating requirements.
WTP distinguishes between safety samples and process samples, and
has plans to accomplish both in a manner that will result in meeting
the WAC and conducting safe and reliable operations in WTP. The current
control strategy for the Pretreatment Facility safety basis requires
confirmatory samples for criticality safety and inventory control
samples for the Low-Activity Waste Facility safety basis. The sampling
portion of the control strategy for criticality safety is in revision
based on previous mixing tests results, which concluded that the
assumptions in the Criticality Safety Evaluation could not be
sufficiently verified in pulse jet mixed vessels. The samples for Low-
Activity Waste Facility safety basis compliance can be obtained with
the current sampling design. DOE will continue to work closely with the
Board staff to establish a common definition of representative samples
as applied to the discussion above.
[FR Doc. 2011-16138 Filed 6-27-11; 8:45 am]
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