[DNFSB
LETTERHEAD]
February 4, 2005
Mr. Paul M. Golan
Acting Assistant Secretary for
Environmental Management
U, S. Department of Energy
1000 Independence Avenue, SW
Washington, DC 20585-0113
Dear Mr. Golan:
The staff of the Defense Nuclear
Facilities Safety Board (Board) recently visited the Hanford Site to review the
Sludge Retrieval and Disposition Project (SRDP). The mission of the SRDP is to remove, process, and package
for disposal approximately 50 cubic meters of radioactive sludge that is present
on the floors of the K-East and K-West Basins at Hanford. A report
documenting the staff’s observations is included as an enclosure to this letter.
The Board notes that the SRDP
continues to experience difficulties in design, engineering, and testing. For example, during the course of design and
fabrication of the sludge consolidation containers, project engineers had to
make several design changes to address issues regarding installation, dose
rate, settling and capture of sludge, and planned retrieval of sludge from the
containers. The Board believes these
continuing design changes are indicative of a lack of fundamental understanding
of the properties and characteristics of the sludge. As a result, defining the scope of work of the
project is not thorough and planning for the life cycle of the project is
incomplete. This in turn is evidence of
continuing difficulties with project management, definition of functional
requirements, and design.
As the enclosed report notes,
there are other indications of continuing design, engineering, and testing
difficulties within the SRDP. These
difficulties include sludge flocculent not performing as designed for use in
the K-East sludge containers; failure of the casing of the hose-in-hose
transfer pump during testing as a result of erosion; insufficient consideration
of engineered controls during the design of sludge retrieval operations, in particular
for the potential increase in airborne radioactivity during sludge-disturbing
activities; and a design that does not preclude the possibility of an
undetected leak during operation of the Hose-in-Hose Transfer Line. Many of these deficiencies stem from an
apparent failure of the core functions of Integrated Safety Management: defining the scope of work, identifying and controlling
hazards, and providing feedback for continuous improvement. Personnel from the Department of Energy (DOE)
Richland Operations Office have also recognized some continuing difficulties
with the project, and have decided to conduct an independent engineering review
of portions of the Hose-in-Hose Transfer Line.
Deficiencies in design,
engineering, and testing have been documented by several independent reviews of
the project and in Fluor Hanford’s Broader Scope Issues report of February 2004,
which also identified causes and corrective actions for the noted deficiencies.
While Fluor Hanford has taken corrective
actions in response to these reviews, the continuing problems noted above
indicate that these corrective actions may not have been effective. Fluor Hanford has committed to completing a
review of the effectiveness of corrective actions identified in the Broader
Scope Issues report to address these continuing issues. However, it appears that the system for
verifying the effectiveness of corrective actions is inadequate.
The Board is concerned about the
continuing difficulties and slow progress of the SRDP.
Quality design, engineering, and
testing are crucial to safe and efficient equipment operation that minimizes
workers’ time in hazardous areas and minimizes their exposure to hazardous conditions.
Therefore, pursuant to 42
U.S.C. § 2286b(d), the Board requests that responsible DOE personnel
provide a report to the Board within 60 days of receipt of this letter that documents
the effectiveness of the corrective actions reportedly in place to address the engineering
difficulties of the SRDP. The report
should also identify further corrective actions needed in the areas of design,
engineering, and testing, as well as steps to be taken to ensure that future
corrective actions are reviewed for effectiveness. Additionally, the report should address the
noted Integrated Safety Management failures regarding definition of the scope
of work, identification and control of hazards, and feedback and improvement.
Sincerely,
John T. Conway
Chairman
c: Mr. Keith A. Klein
Mr.
Mark B. Whitaker, Jr.
Enclosure
DEFENSE
NUCLEAR FACILITIES SAFETY BOARD
Staff
Issue Report
January
11, 2005
MEMORANDUM FOR: J. K. Fortenberry, Technical Director
COPIES: Board
Members
FROM: M. Feldman and D. Ogg
SUBJECT: Sludge Retrieval and Disposition
Project, Hanford Site
This report documents a review
of the K-Basins Sludge Retrieval and Disposition Project (SRDP) at the Hanford
Site conducted by the staff of the Defense Nuclear Facilities Safety Board
(Board) during December 7-9, 2004. Staff members M. Feldman, D. Ogg, and R. Quirk
and Site Representative D. Grover discussed aspects of several SRDP subprojects
with representatives of the Department of Energy Richland Operations Office
(DOE-RL) and Fluor Hanford, Inc. (FH).
Background. The SRDP consists of several subprojects, including sludge
retrieval from the K-East Basin North Loadout Pit (NLOP), consolidation of
K-East Basin sludge into new containers in the basin, transfer of the
consolidated K-East Basin sludge to the K-West Basin via a hose-in-hose
transfer line (HIHTL), and removal and treatment of all sludge for disposal as transuranic
waste. Under FH’s Waste Management
Project, NLOP sludge is to be stored at T-Plant, where operators plan to
install and operate a grouting system for this sludge stream. Retrieval of NLOP sludge and consolidation of
K-East Basin sludge are ongoing. All
other subprojects
are in varying stages of design, procurement, and construction.
Consolidation of Sludge. The contractor has installed two of the four containers to
be used for consolidation of K-East Basin sludge. Consolidation of the sludge has begun in order
to clear space for installation of the remaining two containers. During the design and fabrication of these
containers, as well as those to be installed in K-West Basin, project engineers
had to make several design changes to address issues regarding installation,
dose rate, settling and capture of sludge, and planned retrieval of sludge from
the containers.
The staff believes these
continuing design changes are indicative of poor planning for the life cycle of
the project and a lack of integration among subprojects. Consideration of sludge retrieval was
relegated to the HIHTL subproject, where the design schedule was not integrated
with that for sludge consolidation. Functional requirements were not formally
developed and approved until the construction phase of the consolidation
subproject. This in turn is evidence of continuing
difficulties with project management, definition of functional requirements,
and design, and of a failure to adequately define the scope of work as required
by Integrated Safety Management.
Additionally, the flocculent system
to be used to enhance settling and minimize clouding of the basin water did not
perform as expected during testing. After more thorough interaction with outside
experts and the vendor, gross conceptual problems were corrected, and the
system was redesigned. The effectiveness
of the flocculent system is still not well understood, however, and the
contractor is currently reevaluating use of the system. Operators began consolidating the K-East Basin
sludge into new containers without the flocculent system.
The Board’s staff noted the
potential for a plume of cesium to form in the
basin water during sludge consolidation. Excess cesium entrained in the sludge will be
released into the water when the sludge is disturbed, and some sludge and
cesium will be forced close to the surface during the consolidation process. This increased cesium content in the water
could contribute to higher airborne radioactivity levels. Such an increase in water and airborne radioactivity
has been observed during past sludge and fuel processing operations and has
caused operational difficulties. The
project engineers rely on monitoring and personal protective equipment to
protect workers, instead of using engineered and/or administrative controls to mitigate
this hazard. Although significant spikes
in radioactivity levels have not been observed, the probability of this hazard
will increase as consolidation continues and higher-activity sludge is
disturbed.
Hose-in-Hose Transfer Line.
Contractor engineers, working with a subcontractor, completed
the final design of the HIHTL and submitted the final design package to the Department
of Energy (DOE) for approval. Four
booster pump stations will provide the motive force for transferring sludge
slurry from K-East to K-West Basin. The
design includes five 500-foot sections of hose, each consisting of two hose
lengths connected by a swaged steel connector.
The leak detection system for
the HIHTL consists of conductivity probes placed in the sump of each booster
pump station and at the entrance/exit point of each basin. The entrance point into each booster pump
station is 2 to 3 feet above the ground, where the transfer line lies. For a leak in the inner hose to be detected,
the entire annulus of a 500-foot section of the HIHTL would have to fill before
the sludge slurry could spill over into the pump station. This amounts to a leak of approximately 240
gallons of sludge slurry and almost an order of magnitude increase in dose
rates in the vicinity of the hose before a leak can be detected. Recent efforts to improve water quality in the
basins have led to conductivity levels in the basins that challenge the lower
detection limit of the leak detectors. It is not clear whether the uncertainties
associated with the instrument and water testing have been adequately
considered to ensure the operability of the system or whether the current
conductivity represents a bounding low condition. The preliminary Documented Safety Analysis
does not include controls to ensure that conductivity is within acceptable
ranges prior to sludge transfers.
Abrasion testing of the HIHTL
showed that the material used, ethylene propylene diene monomer, has good
erosion and radiation resistance, but the pump casing used in testing failed because
of erosion after only 2 hours of use. Previous experience in the K-Basins has shown
that the sludge has a tendency to erode metal equipment, such as pumps. It is unclear whether the potential for
erosion of the HIHTL pumps was considered before the test pump failed. Selection and testing of the HIHTL transfer
pumps have not been completed, but procurement has proceeded to accommodate
long lead times. The contractor is
considering installing an additional pump as a spare in each booster station as
a compensatory measure. The Board’s
staff remains concerned about this pattern of project management, whereby
initial procurement and construction precede the completion of testing and
resolution of project uncertainties.
The dose rate calculation for
the HIHTL accounted only for the nuclides cobalt-60 and the metastable
barium-137, a daughter of cesium-137. While the barium was expected to be the primary
contributor to dose, cobalt was also included because of its high-energy gamma
photons. All other isotopes identified in the
sludge were characterized as producing particle radiation and were not expected
to contribute to overall dose rates (as particles will be completely shielded
by the pump, hose walls, and water). Europium-154 has a higher activity than
cobalt-60 in the sludge and also emits a strong gamma, but was not included in
the dose rate calculations. FH’s design
reviews did not identify this erroneous design assumption in the
subcontractor’s dose calculations. Subcontractor analysts performed a revised
dose rate calculation in response to questions raised by the Board’s staff and
concluded that the dose estimate should be increased by 15 percent.
Sludge Stabilization and
Packaging. FH recently awarded the contract
for the treatment and packaging of the K-Basin sludge to British Nuclear Fuels,
Ltd. (BNFL). The project will include
transfer of sludge to a nearby facility; a high-temperature, high-pressure bath
for oxidation of small fuel pieces in the sludge; and subsequent grouting of
all sludge in 55-gallon drums. Under
this contract, BNFL will not only design, build, and test equipment, but also
initially operate the system for FH. The
plan is for these activities to be conducted within facilities operated by FH,
and to be turned over to FH for completion of sludge processing. Coordination of the two contractors through
operational readiness reviews may pose complications, and a strategy to this
end has not been developed. The staff is
reviewing the contract and evaluating the flowdown of requirements.
Conduct of Design and
Engineering. In the early stages of the SRDP,
the contractor experienced a number of deficiencies in the design, engineering,
and testing of sludge retrieval equipment. These deficiencies were documented by several
independent reviews and in FH’s February 2004 Broader Scope Issues report,
which also identified causes and corrective actions for the noted deficiencies.
In the area of design, for example, the
functional design criteria for the project did not establish an adequate basis
for a sound design. Additionally,
schedule pressure resulted in the design’s progressing without complete
information, necessitating design changes as needed information became
available. Schedule pressure has also
caused procurement and fabrication to proceed before the completion of final
design and testing.
In the area of procurement,
assessors had previously noted that project personnel had issued long-lead
procurements prior to the completion of adequate designs and hazard analyses. This problem is mirrored by the completion of
the design for the HIHTL and the start of procurement prior to the completion
of erosion testing to validate design assumptions. This testing identified design problems that
had to be corrected, as well as the need for a major redesign of the pumps and
pump housing. Again, procurement has
preceded completion of testing of the new pump system. Moreover, as a result of the need to
reevaluate pump requirements at this late stage, the pump deemed best suited
for this application will not be available because of the long lead time for
its procurement.
The noted deficiencies are
indicative of programmatic failures in the core functions of Integrated Safety
Management. Examples include the failure
to properly identify the potential hazards associated with sludge-disturbing
activities; to develop adequate controls for a leak during sludge transfer; and
to define the scope of work, in some subprojects. DOE management has decided to conduct an
independent engineering review of the HIHTL project to address these programmatic
issues regarding design, engineering, and testing.
During the operational readiness
review for retrieval of NLOP sludge, DOE-RL recognized that some project
deficiencies persisted and directed that the contractor develop a new
corrective action plan. In response, the
contractor issued an SRDP Continuous Performance Improvement Plan in July 2004.
According to this plan, however, extensive corrective
actions were already ongoing to address engineering deficiencies, and no other
specific actions would be taken. The
staff found that the corrective actions called for in the February 2004 Broader
Scope Issues report consisted of changes in project management, assignment of
additional personnel to the project, and changes to some of the engineering
procedures. Given the recent
observations noted in this report and those made during previous reviews
conducted last year, the staff believes that the corrective actions have not
been effective, and that further attention in the areas of design, engineering,
and testing is needed. FH has committed
to completing a review of the effectiveness of corrective actions identified in
the Broader Scope Issues report to address continuing programmatic issues. The Board’s staff encouraged FH to develop a
set of metrics to assist in the assessment of the engineering program and
identify areas still needing improvement.