[DOE LETTERHEAD]
National Nuclear Security Administration
The Honorable John T. Conway
Chairman
Defense Nuclear Facilities Safety Board
625 Indiana Avenue, N.W.
Washington, D.C. 20004
Dear Mr. Chairman:
The Implementation Plan (IP) for Defense Nuclear
Facilities Safety Board Recommendation 97-2, Criticality Safety, requires a
quarterly status report. Enclosed is the Department of Energy’s quarterly
status report for the third quarter of Fiscal Year FY 2001, which ends on June
30, 2001.
The IP contains 30 milestones, all of which have now
been completed. Although all
commitments have now been met, stability of finding for the Nuclear Criticality
Safety Program (NCSP) is a primary concern.
The NCSP Management Team is working with program sponsors to review the
NCSP in detail, validate program requirements, achieve agreement on appropriate
scope and level of necessary support, and establish a process that stabilizes
funding support for the program. This
process will also yield an updated Five-Year Plan for the NCSP. I remain committed to working closely with
the contributing program offices to stabilize funding for the NCSP, as well as
resolving the other issues raised in your July 20, 2001, letter to the Secretary
prior to proposing closure of the Recommendation.
David . Crandall
Assistant Deputy Administrator
for Research,
Development, and Simulation
Defense Programs
Enclosure
cc (w/encl):
M. Whitaker, S-3.1
J. Roberson, EM-1
K. Carlson, DP-1
J. Gordon, NA- 1
QUARTERLY STATUS OF THE IMPLEMENTATION PLAN
FOR
DEFENSE NUCLEAR FACILITIES SAFETY BOARD RECOMMENDATION
97-2
THIRD QUARTER FISCAL YEAR 2001
The Department of Energy (DOE) began implementing
Defense Nuclear Facilities Safety Board (DNFSB) Recommendation 97-2 in January
1998 by formally establishing the Nuclear Criticality Safety Program
(NCSP). Each of the seven NCSP Tasks
(Critical Experiments, Benchmarking, Analytical Methods, Nuclear Data, Training
and Qualification, Information Preservation and Dissemination, and Applicable
Ranges of Bounding Curves and Data) is dependent upon the others for a
successful program. Implementation of
the NCSP is being accomplished according to the Five-Year NCSP Plan which was
published in August 1999.
The Nuclear Criticality Safety Program Management Team
(NCSPMT) and the Criticality Safety Support Group (CSSG) are performing their
respective chartered functions in supporting the Responsible Manager’s
execution of the Implementation Plan (IP).
During the quarter, the NCSPMT and CSSG reviewed the NCSP, provided
justification necessary for maintaining funding support, developed formal
comments on the Departmental Guides for 10 CFR 830, Nuclear Safety, and
finalized the response to DNFSB Technical Report # 29, Criticality Safety at
Department of Energy Defense Nuclear Facilities, which was forwarded to the
DNFSB in May 2001.
Regarding ongoing efforts to stabilize funding for the
NCSP, the NCSPMT and CSSG had several meetings during the quarter to review NCSP
requirements, determine a baseline budget for validated requirements, achieve
agreement on an appropriate scope and level of necessary support, and establish
a process that stabilizes funding support for the program. This process is
targeted for completion by the end of September 2001
and will also yield an updated Five-Year Plan for the NCSP.
Because all 30 of the Recommendation 97-2 milestones
are completed, this quarterly report will focus on the status of activities for
each of the seven NCSP elements. Steady
progress is being made in all seven of the NCSP task areas. Accomplishments and key issues in each of
the program task areas which arose during the period are contained in the
following sections of the report.
Critical Experiments
Experiments were conducted on three of the five Los
Alamos Critical Experiments Facility (LACEF) assemblies during this
quarter. In addition to performing
these experiments, four criticality safety courses were also provided (one
5-day basic course, one 5-day advanced course, and two 2-day courses). A status of activities by critical assembly
is as follows:
Flattop:
Flattop was inoperable for this entire quarter due to a malfunction of the
control rod drive system. The newly
redesigned control rod drive system has arrived at Technical Area (TA)- 18, and installation will begin
soon. A restart notification will be
delivered to the DOE/Los Alamos Area Office (LAAO) within the next few weeks,
and restart should occur in approximately 6 months.
Comet/Zeus: Installation of the sinusoidal actuator was
completed during this quarter, and testing has commenced. This actuator will eventually be used to
measure the worth of the CERES samples (third on the list of priority critical
experiments) on both the Comet and SHEBA critical assemblies. A total of 21 Comet operations were
performed during this quarter. A benchmark write-up of the current Zeus
configuration (3 cm graphite, oralloy plate, 3 cm graphite) was completed and
submitted to the benchmark evaluation group.
Once the test of the actuator has been completed, the remaining Zeus
configurations (e.g., all oralloy and other
interstitial materials) will be assembled.
SHEBA: SHEBA remains inoperable as a result of
failure of the cover gas system. It was
discovered that the cover gas system, which is designed to sweep out the
radiolytic gases and pass them through the catalytic recombine, was not
performing at full capacity. This
resulted in the declaration of an Unusual Occurrence and termination of SHEBA
operations. Repair of the cover gas
system continues. A Potentially
Inadequate Safety Analysis positive Unreviewed Safety Question Determination
has been submitted to DOE/LAAO. Once
approval is received, the system will be repaired and SHEBA will be restarted. This is expected to take approximately 9
months.
Godiva: Ten Godiva operations were performed this
quarter in support of criticality safety courses, operator training, neutron
dosimetry measurements for ESH-4 and ESH- 17, and benchmarking of nuclear
instrumentation for the emergency response program. DOE/LAAO granted permission for neutron measurements with
instruments in the glory hole and approved a test plan for add-on irradiation
experiments.
Planet:
Eighteen operations were performed this quarter in support of 97-2 experimental
activities, criticality safety courses, and operator training. Experimental activities with waste/tuff
materials continue. Work also continues
on documenting the results of these activities for the benchmark program. Two benchmarks were completed and submitted
to the benchmark evaluation group.
These benchmarks were returned by the group to have some discrepancies
resolved. The two benchmarks are
currently being reworked and will be resubmitted to the evaluation group by the
end of August. A new experimental
configuration involving U(93) foils, polyethylene plates, and Gadolinium foils
was initiated during this quarter.
While initial criticality was achieved during the fourth quarter of FY
2001 (July 19, 2001), the vast majority of the preparatory work was performed
during the third quarter.
Other Significant Accomplishments:
One of the more significant accomplishments of the
last quarter was the completion of the TA- 18 Basis for Interim Operation and
the new Technical Safety Requirements.
This is the final deliverable (to DOE/ LAAO) of a multi-year
multi-million dollar safety analysis effort that completely redefines the
Authorization Basis at TA- 18. In
addition, the biennial crew member/crew chief recertification was completed,
and six new LACEF crew members were certified.
Benchmarking
The 2001 International Criticality Safety Benchmarking
Evaluation Project (ICSBEP) Working Group Meeting was held from June 11 through
June 15, 2001. The meeting began with a
tour of the critical facilities at Argonne National Laboratory -Weston Monday,
June 11, and culminated in a series of technical meetings, June 12 through June
15, 2001, in Jackson Hole, Wyoming.
Representatives from the United States, United Kingdom, France, Japan,
the Russian Federation, and Slovenia participated in this meeting. Twenty-five new evaluations were reviewed at
the meeting along with three evaluations that underwent significant revision. Twenty-three of the twenty-five new evaluations
were approved for publication. Twelve
of the approved evaluations were contributed from outside the United
States. Of the eleven evaluations
contributed by United States participants, four were provided by Argonne
National Laboratory, two were provided by the Oak Ridge National Laboratory,
and five were contributed by the Idaho National Engineering and Environmental
Laboratory or its subcontractors (three of the five were provided by
Westinghouse Safety Management Solutions at the Savannah River Site). Additional configurations were added to
previously published evaluations by the Lawrence Livermore National Laboratory
and the Los Alamos National Laboratory.
Also reviewed at the meeting was a “Guide to the
Expression of Uncertainties” and the Database for the International Criticality
Safety Benchmark Evaluation Project (D.I.C.E.). The “Guide to the Expression of
Uncertainties” was prepared by ICSBEP participants from France and was first
presented to the ICSBEP in June of 2000.
D.I.C.E. was developed jointly by the Organization for Economic
Cooperation and Development - Nuclear Energy Agency (OECD - NEA) and the
ICSBEP. The guide and D.I.C.E. will be
published, for the first time, with the 2001 Edition of the Handbook.
A presentation entitled “Preview of the 2001 Edition
of the International Handbook of Evaluated Criticality Safety Benchmark
Experiments” was given at the American Nuclear Society (ANS) Meeting in
Milwaukee, Wisconsin. A second
presentation entitled “The Status of the International Criticality Safety
Benchmark Evaluation Project” was given at the DOE Nuclear Criticality Safety Program Review that was
held in conjunction with the ANS Meeting.
A series of previously undocumented 233U solution
experiments was documented and published by the experimenter, J. T. Thomas
(retired) and C. M. Hopper (Staff at ORNL).
The reference for this report
is:
J.
T. Thomas and C. M. Hopper, “Critical Experiments With Aqueous
Solutions
of 233U02(N03)2, 0RNL/TM-2000/245,
Oak Ridge National
Laboratory,
May 2001.
Nuclear Data
ORNL: With the
restored funding for the data measurement subtask, effort resumed on the
fabrication of sample holders and the design of samples for potassium and
fluorine. Effort continued on various data
reduction and evaluation tasks. A
re-evaluation of fluorine utilizing existing data was initiated. Evaluations of the chlorine capture and
transmission measurements and the silicon capture measurements were
completed. Evaluations in progress
include Cl-35 and Cl-37. An interesting
development is the importance of the proton production by neutron capture
reaction. It turns out to make a
significant contribution to total neutron absorption, and it has not been
included in previous evaluations for chlorine.
The unresolved resonance parameters for U-235 are being evaluated with
the TNG code. The SAMMY code has been
enhanced to consider multiple scattering in its data evaluation. A summary of the status of the Nuclear Data
subtasks was presented at the NCSP review in Milwaukee. A paper on silicon has been prepared for the
upcoming nuclear criticality safety topical meeting. This paper demonstrates integration of nuclear data, critical
experiments, analytical methods and the ICSBEP to produce improved capability
for the evaluation of fissile systems containing silicon.
LANL: Effort
focused on maintenance and enhancement of the NJOY cross section processing
system and the generation and testing of new libraries for the MCNP transport
code. Additionally, testing continued on the new U-238 evaluation that makes
some significant enhancements to the existing ENDF/B-VI evaluation. Some of the notable changes/ improvements
are: 1) new elastic and inelastic
scattering information based on coupled-channel optical model ECIS
calculations, width-fluctuation compound nucleus reactions, and direct reaction
calculations; 2) new channel cross
sections for reactions such as (n, n’), (n, 2n), and (n, 3n); 3) new
fission cross section based on Lisowski’s more recent LANSCE measurements;
and 4) new direct + compound elastic
calculation which results in a new average scattering angle, mu-bar. With these modifications, agreement in the
calculation of the FLATTOP critical assembly is improved. LANL has completed a new O-16 evaluation
that includes significant improvements.
It is being tested against a number of benchmarks, and it is performing
well. A report on the status of NJOY
was presented to the NJOY User’s Group meeting sponsored by the NEA and held in
May in Aix-en-Provence, France. The
topic of Software Quality Assurance remains very important at Los Alamos, and
new draft procedures have been circulating for evaluation and comment. The new web-based “issue tracker” is giving
NJOY users around the world access to the latest issues and their resolutions.
ANL: Benchmarking
activity is continuing. Data testing
for new LANL evaluations of U-238 and O-16 was conducted, and the Cross Section
Evaluation Working Group data community was appraised about performance of the
new U-238 data. Some progress has been
made on the comparisons of Monte Carlo (VIM and MCNP) point libraries,
identifying deficiencies in the processed files.
Analytical Methods
Oak Ridge National
Laboratory (ORNL): Staff at ORNL continued to maintain KENO
software and assist the nuclear criticality safety community in the use of this
software. In April, a SCALE/KENO-VI
workshop was conducted at ORNL for ten participants from government, industry,
and academia. The NCSP provides for
base funding in KENO user assistance, as well as the preparation of training
materials. During this quarter,
substantial coding was performed to assure the compatibility of the new SCALE
multi-cell option with the various SCALE search options. The new SCALE multi-cell option provides for
the simultaneous treatment of multiple fuel cell types in problem-dependent
cross section processing. A new version
of CENTRM, which features greatly improved memory management, has been
implemented into the prototypic SCALE Version 5.0. Presentations were made at
the Milwaukee ANS meeting on a CENTRM application, as well as on the status of
the NCSP Analytical Methods subtasks.
Significant assistance was rendered to the SCALE/KENO user community.
Los Alamos National
Laboratory (LANL): Staff at LANL continued to maintain MCNP
software and assist the nuclear criticality safety community in the use of this
software. In addition, an Advanced MCNP
class was taught at LANL in April, and an Introductory MCNP class was taught at
LANL in May. Work continued on updates
to the MCNP manual, including the addition of a 12-page index in the “pdf’
version of the manual on the LANL web site.
Also, benchmark specifications have been developed for several Rossi
alpha sub-critical measurements. Among
features of interest to the criticality safety community that are being worked
on for the future are automatic source point generation for eigenvalue problems
and improved source definition capability for repeated structure
geometries. These features tie in with
the solution of fission source convergence studies being performed on an
international basis. A new version of
MCNP has been shown to perform very efficiently in the parallel mode.
Argonne National Laborato
ry (ANL): Staff at ANL continued to maintain the VIM code and to perform
the studies on fission source convergence.
American Standard Code Information Exchange versions of the VIM
libraries were sent to the Radiation Safety Information Computational Center to
accommodate non-Sun installations.
Staff at ANL completed a total of 354 calculations for the four OECD -
NEA Source Convergence Benchmark sets and submitted the results to the
appropriate analysts in the Expert Group on Source Convergence in
Criticality-Safety Analyses. A subset
of the results, including the ANL results, were reviewed at an informal meeting
of the Expert Group at the ANS Annual Meeting at Milwaukee. A permanent update of the cross section
processing codes was completed along with the necessary quality assurance, and
the revised codes were placed in production.
In addition to the modifications for processing ENDF/B-VI and JEF-2.2,
the codes’ readability, maintainability, bounds checking, and internal
documentation were improved. The latest
U-235 evaluation has been accommodated by further code modifications that will
be included in the next production code update.
Training and
Qualification
This program element includes
three subelements: (1) hands-on
criticality safety training at LANL;
(2) training development; and,
(3) criticality safety qualification program activities.
Hands-on criticality safety
training continued at LANL during the quarter.
One basic 5-Day Course (April 23-27) and an advanced 5-Day Course (June
4-8) were conducted. Two projects were
initiated this quarter under the training development subtask. Funds were transferred to ORNL to co-sponsor
conversion of the criticality accident slide rule report into a PC-based
program. Funds were also transferred to
the Westinghouse Savannah River Company for the development of one or more
Nuclear Criticality Safety Engineer Training modules on the chemistry and
criticality safety of uranium and plutonium separations. The modules are due to be completed next
quarter.
The Department continued to
interact with its contractors regarding development and implementation of
training and qualification programs for contractor criticality safety
staff. The Oak Ridge Operations Office
and criticality safety staff from the Office of Environment, Safety and Health
held discussions with the Bechtel Jacobs Company regarding their training and
qualification program. Several
modifications to the program resulted from these discussions that will bring
the program in line with the intent of DOE-STD-1135-99. Also, discussions were held with the DOE
Y-12 Area Office regarding the potential of criticality safety staff from the
Office of Environment, Safety and Health performing a review of the implementation
of the training and qualification program at Y-12.
Information
Preservation and Dissemination
This program element
currently contains two sub-elements: (1) the Criticality Safety Information
Resource Center (CSIRC); and (2) NCSP web page development.
Regarding the CSIRC Program,
the following progress has been made. A
videotaping session of Oak Ridge pioneers, patterned after the Los Alamos
sessions in September of 2000, was conducted at Oak Ridge. Scanning of all known Oak Ridge logbooks was
also completed. Scanning of logbooks
and related historical documents continues at the Lawrence Livermore National
Laboratory. Requests for hard copies
and CDs of the documents LA-1086O, LA-12808, LA- 13638, and their reference
sets are being filled. Bob Rothe
continued to refine his History of the Rocky Flats Critical Mass Laboratory
document, with publication planned later this year. A first videotape of the heritage series was edited and released
during this quarter. This was a
45-minute tape showing Hugh C. Paxton, the leader of the Critical Experiments
Group at LANL from 1950 to 1975, discussing aspects of the programs during
these years as well as commenting on regulatory changes and impacts. The major Los Alamos Heritage Video sessions
that were conducted over a 3-day period in September of 2000 are being prepared
for reproduction and distribution.
Regular videotapes, DVD, and CDs will be available in the near future.
The NCSP web site at LLNL is
being maintained and improved. This web
site provides technical information and the latest information of interest to
the criticality safety community. It
also serves as a pointer to other web sites which are important to the
NCSP. For the second quarter of FY 2001,
the NCSP web site highlights included the following. Several frame-based versions of the new website design were
developed and released for review.
Nuclear Criticality Safety Engineer Training Module 8, “Hand Calculation
Method – Part I,” the University of New Mexico newsletter, and the “CSSG Review
of draft Guides to 10 CFR 830” and links to the PDF version of the Guides were
added to the web page. The new website
design was presented at the NCSP workshop during the ANS annual meeting at
Milwaukee, WI. NCSP web site usage
statistics were generated, and discussions with Hanford about updating the
Hanford Database were initiated.
Applicable Ranges of
Bounding Curves and Data
During the third quarter of
Fiscal Year 2001, three of the five technical program tasks were actively
addressed. Emphasis was placed on
moving software into production status, prior to the further development of
guidance on its use and/or the performance of sensitivity/uncertainty studies.
Under subcontract extension,
the University of California, Berkeley, continued to modify the SWANS code for
performing geometric optimization.
Further work, at a reduced
level, was conducted on the development of the SEN1 and SEN3 computational
sequences for producing sensitivity coefficients for criticality safety models
within the SCALE code system. The
implementation of methods to compute the sensitivity of k-eff to the group cross section resonance
processing with BONAMI and NITAWL-II was completed. Further testing of these new techniques was performed with both
SEN 1 and SEN3.
A demonstration of the use of
the AROBCAD methodology in the establishment of safe margins of subcriticality
was performed and documented as a paper for the upcoming topical meeting on
nuclear criticality safety. The
demonstration involved a comparison of the new methodology with the results of
a previous safety evaluation of a shipping container utilizing currently
acceptable techniques. This effort was
performed to gain experience in preparing guidance for the use of the AROBCAD
methodology.
The implementation of the
SEN3 methods for SCALES has recently been enhanced to provide the user with
more flexibility in the generation of flux moments for complex systems. The SEN1 and SEN3 control modules have also
been updated to allow the use of the CENTRM point transport code for resonance
processing and to allow the definition of multiple unit cells in a model. Verification cases are being compiled to
ensure accurate calculation of sensitivity coefficients for a variety of
systems.
N1 is undergoing transition
to SCALE5. SEN3 has been optimized to
reduce memory requirements to better address problems involving large energy
group structures or complex geometries.
Application of SEN3 in the evaluation of the complex geometry in
ICSBEP-233-SOL-THERM-O06 indicated a need for enhanced memory management.