[DNFSB
LETTERHEAD]
May 2, 2005
Mr. Thomas P. D’Agostino
Acting Deputy Administrator for
Defense Programs
National Nuclear Security
Administration
U.S. Department of Energy
1000 Independence Avenue, SW
Washington, DC 20585-0104
Dear Mr. D’Agostino:
Recent events during nuclear
explosive operations at the Pantex Plant, described in the enclosure, indicate
continuing deficiencies in the conduct of operations at Pantex. Department of Energy (DOE) Order 5480.19, Conduct of Operations Requirements
for DOE Facilities, requires
that “operations at DOE facilities be conducted in a manner to assure an
acceptable level of safety”. The
significant reliance on operator actions to implement both administrative and
engineered (i.e., tooling) safety controls at Pantex necessitates strict
compliance with conduct of operations requirements.
On several occasions, the
Defense Nuclear Facilities Safety Board (Board) has identified the essential
role that conduct of operations plays in ensuring the safety of nuclear explosive
activities. The Board noted in
DNFSB/Tech-6, Safety
Management and Conduct of
Operations
at the Department of
Energy’s
Defense Nuclear Facilities, that
“the most intensive application of the concept would be found at the more
hazardous facilities subject to the more repetitive types of activities”. Many Pantex nuclear explosive operations meet
these criteria. In an October 2001 letter to DOE, the Board documented concerns
with conduct of operations at Pantex; specifically, procedural compliance.
Subsequent evaluations have indicated improvement in conduct of operations;
however, the recent events at the Pantex Plant have renewed the Board’s concern.
These events include misinterpreting operational conditions, a critical
procedural step being misread, improper removal of tooling from a unit, tooling
being installed backward, and technicians operating tooling in an inappropriate
manner, as detailed in the enclosure. In
addition to the immediate hazards encountered during these events, operational
errors created new hazards and resulted in the need for recovery actions that
were not initially analyzed. These examples
of questionable judgment and not adhering to work procedures indicate that an enhanced
level of rigor is needed.
The threshold for accepting
operational errors at Pantex should necessarily be exceedingly low. The Board believes, based on the complexity of
the operations and the consequences of improper execution associated with
nuclear explosive operations, the conduct of operations at Pantex must meet the
highest standards achievable. Pursuant
to 42 U.S.C. § 2286b(d),
the Board requests a briefing within 30 days of receipt of this letter on the
National Nuclear Security Administration’s path forward to improve conduct of
operations at the Pantex Plant.
Sincerely,
A. J. Eggenberger
Acting Chairman
c: Mr. Daniel E. Glenn
Mr.
Mark B. Whitaker, Jr.
Enclosure
Enclosure
Recent
Operational Events at Pantex Plant
The following paragraphs provide
additional details on recent events at the Pantex Plant:
W76
Cell
Operations, March 30, 2005―During disassembly operations,
production technicians incorrectly determined that the midcase
had begun to separate from the unit. The
production technicians performed subsequent procedural steps during which the
unit separated at an undesired location and a critical electrical component was
inadvertently severed. After the unit
had been lowered and put in a safe and stable configuration, the process
engineer observed that the “telltale” needle on the force gauge for the tooling
was reading higher than allowed per procedure. It was later determined that the force applied
to the main charge high explosive potentially exceeded the “maximum allowed
force” described in the approved authorization basis. The configuration of the unit resulted in a
positive unreviewed safety question determination and was outside the scope of
previous nuclear explosive safety studies. BWXT-Pantex developed and received site office
approval for a Justification for Continued Operations and a Nuclear Explosive
Engineering Procedure that detailed the proposed path forward. In addition, a Nuclear Explosive Safety Change
Evaluation was performed to assess the proposed path forward.
W76 Cell Operations, April 26, 2005―During
disassembly operations intended to recover from the anomaly described above, a
safety feature of the tooling prevented production technicians from applying
the maximum force allowed per procedure to the high explosive main charge. The production technician supervisor directed
the production technicians to apply a quick force on a jackscrew in an attempt
to bypass the safety feature and apply the maximum force allowed per procedure.
The force was applied in an abrupt
motion, and the force gauge showed that the maximum procedurally allowable
force was exceeded by 350 pounds. BWXT-Pantex did not suspend operations and
place the nuclear explosive device in a safe and stable configuration until
nearly three hours later. Potential
contributing factors to the event include the supervisor directing the
production technicians to perform the operation in a non-standard and unpracticed
way, the lack of a questioning attitude on the part of the production
technicians when directed to perform an activity in an unusual manner, and the
failure to inform the tooling engineer, who was observing the operation, that
the tooling would be cycled in the abrupt manner described.
W56 Cell Operations, April 11,
2005―During dismantlement operations, a procedural step was
misread, and production technicians subsequently removed the wrong piece of
tooling from a unit. Upon recognizing
the error, the unit was lowered and covered until a backout
procedure could be developed. Potential
contributing factors to this event include a poor shift turnover between
technicians, inattention to detail and lack of awareness of the unit’s configuration,
lack of a questioning attitude by the technicians when an unexpected condition arose,
and starting a section of the procedure near the end of a shift.
W78 Bay Operations, April
12, 2005―Production technicians incorrectly installed a lifting and
rotating fixture into an assembly cart. A
unit was
installed into the lifting and rotating fixture, and production technicians
were unable to transfer the unit from the assembly cart to the transportation
cart. BWXT-Pantex subsequently suspended
disassembly operations. To recover, a
hoist was used to lift the unit from the lifting and rotating fixture in order
to reorient the fixture into the assembly cart.