[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

[[Page 37799]]

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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