[DNFSB
LETTERHEAD]
The Honorable Linton Brooks
Administrator
National Nuclear Security Administration
U. S. Department of Energy
Dear Ambassador Brooks.
The staff of the Defense Nuclear Facilities
Safety Board (Board) recently conducted a review of hoisting and rigging
operations, equipment, and safety documentation at the Nevada Test Site (NTS). The Board’s staff focused on reviewing
hoisting and rigging practices at the Device Assembly Facility, U1a Complex,
G-tunnel, and the Radiological Waste Management Complex. The Board’s staff noted two shortcomings that
should be addressed to ensure equipment relied upon for safety is appropriately
maintained.
Documented Safety Analyses are being
developed at NTS that include postulated events involving mechanical insults
and drops of nuclear devices and materials.
Several of the postulated accident scenarios could result in significant
radiological or chemical exposures to workers and therefore, appear to warrant
safety-significant controls. However,
the hoisting and rigging equipment involved in many of these scenarios has not
been classified as safety-significant.
NTS does not appear to have a formalized
process to compare the maintenance recommendations of a manufacturer, typically
found in the equipment’s owners manual, to the facility’s maintenance
procedures or routine inspection program.
Equipment maintenance and inspection requirements are credited as
reducing risk for some systems relied upon for safety.
An issue report on this review is enclosed
for your information and use as appropriate.
Sincerely,
John T. Conway
Chairman
c: The
Honorable Beverly Ann Cook
Ms. Kathleen A.
Carlson
Mr. Mark B.
Whitaker, Jr.
Enclosure
DEFENSE NUCLEAR FACILITIES SAFETY BOARD
Staff Issue Report
MEMORANDUM
FOR: J. K. Fortenberry, Technical Director
COPIES: Board
Members
FROM: D.
Kupferer
SUBJECT: Review
of Hoisting and Rigging at the
This report documents a review of the
hoisting and rigging program at the Nevada Test Site (NTS) conducted by the
staff of the Defense Nuclear Facilities Safety Board (Board). The staff focused on reviewing the
organization, management, and procedures related to hoisting and rigging practices
at the Device Assembly Facility (DAF), Ula Complex (Ula), G-tunnel, and the Radiological
Waste Management Complex (RWMC), including the storage and disposal sites at Areas
3 and 5.
General. Personnel representing the National Nuclear
Security Administration’s (NNSA) Nevada Site Office (NSO), Bechtel Nevada (BN),
Los Alamos National Laboratory (LANL), and Lawrence Livermore National
Laboratory (LLNL) participated in the review. The specific topics covered during the review
included:
The Board’s staff also participated in
facility walk-downs at DAF, Ula, and Area 3 radiological waste disposal
operations, to examine hoisting and rigging equipment. The walk-downs included observing on-going
hoisting and rigging operations.
Overall, the hoisting and rigging program at
NTS has identified most of the appropriate industry codes and guidance. However, the Board’s staff noted two
shortcomings that should be addressed to ensure equipment relied upon for safety
is appropriately maintained: (1) the
majority of hoisting and rigging equipment is not currently classified as
safety-significant despite the fact that some equipment is credited in the
documented safety analyses and relied upon for worker safety, and (2)
manufacturer’s recommendations are not consistently applied in the ongoing maintenance
and inspection program. A noted strength
of the hoisting and rigging program at NTS is the diligence demonstrated at
tracking the certifications of hoisting and rigging personnel.
Hoisting
and Rigging Standards, Codes, and Industry Guidance. Identifying hoisting and rigging standards
and codes is complicated at NTS due to the organizational structure of the site’s
facilities and programs. In general, BN
provides hoisting and rigging support to LANL and LLNL programs and is
therefore responsible for the operation, maintenance, inspection, and certification
of cranes and hoists. The exception to
that generality is that LANL or LLNL will periodically ship hoisting and
rigging equipment to NTS for use with a particular nuclear device.
BN Company Directive (CD) CD-0444.070, Hoisting Apparatus, Cranes, and Conveyors,
is the upper tier document for hoisting and rigging equipment procured and
operated by BN. CD-0444.070 flows down
to other CDs and Organizational Procedures (OP). BN references the appropriate industry codes,
Federal regulations, and Department of Energy (DOE) standards in the CDs and
OPs (with the possible exception of ASME NUM-1, Rules for Construction of Cranes, Monorails, and Hoists, and ASME
NOG-1, Rules for Construction of Overhead
and Gantry Cranes). However, BN
personnel did not demonstrate strong understanding of the requirements and
guidance described within these codes, regulations, and standards.
NSO and BN could benefit from participating
in DOE’s Hoisting and Rigging Technical Advisory Committee (HRTAC). The HRTAC is an advisory body that supports
policy efforts aimed at ensuring the safe performance of hoisting and rigging
activities at DOE and NNSA facilities through the review and resolution of
identified generic hoisting and rigging safety issues. HRTAC circulates information to DOE site
offices regarding recent equipment failures and both corrective and preventive
maintenance recommendations. The
following DOE site offices and their associated contractors are currently
involved in HRTAC in some capacity: Savannah
River Operations Office, Livermore Site Office, Idaho Operations Office, Kansas
City Site Office, Chicago Operations Office, and the Richland Operations Office.
Safety
Classification of Equipment.
Safety-class structures, systems, and
components (SSCs) are defined in Title 10, U.S. Code of Federal Regulations,
Part 830, Nuclear Safety Management,
(10 CFR 830) and DOE Standard 3009, Preparation
Guide for U.S. Department of Energy Nonreactor Nuclear Facility Documented
Safety Analyses, (DOE-STD-3009-94) as “structures, systems, or components
including portions of process systems, whose preventive and mitigative function
is necessary to limit radioactive hazardous material exposure to the public, as
determined from the safety analyses.” Safety-significant SSCs are defined in 10 CFR
830 and DOE-STD-3009-94 as “structures, systems, or components which are not
designated as safety-class SSCs but whose preventive or mitigative function is
a major contributor to defense in depth and/or worker safety as determined from
safety analyses.” DOE-STD-3009-94
continues, “as a general rule of thumb, safety-significant SSC designations
based on worker safety are limited to those SSCs whose failure is estimated to
result in a prompt worker fatality or serious injuries or significant
radiological or chemical exposures to workers.”
Documented safety analyses are being
developed at NTS that include postulated events involving mechanical insults
and drops of nuclear devices and materials.
Several of the postulated accident scenarios could result in significant
radiological or chemical exposures to workers and therefore appear to warrant a
safety-significant controls. However,
the hoisting and rigging equipment involved in many of these scenarios has not
been classified as safety-significant. Defense-in-depth
controls do exist to mitigate the consequences of some postulated events.
For example, the documented safety analysis
for the RWMC includes an evaluation of a scenario in which an inner container
is dropped as it is being removed from an overpack container during intrusive
sampling activities. This event has been
defined as an anticipated event that would have significant consequences
(Severity-of-Consequence Level A) to the worker. Two specific controls are in place to reduce
the potential consequences to the worker associated with the event: (1) the equipment design, including design of
the drum hoist; and (2) a maintenance, testing, and inspection program. These controls effectively reduce the
Severity-of-Consequence Level of this event from an unmitigated consequence of
Level A (significant) to a mitigated consequence of Level B (moderate). However, the safety designation of the drum
hoist is defense-in-depth, as opposed to safety significant. In
addition, some of the inner containers involved in the aforementioned drop
scenario are unvented. The consequences
associated with dropping an unvented container have not been analyzed.
A second example exists at Ula. Subcritical Experiment (SCE) devices could be
involved in drops or mechanical insults that could result in worker injury or
radiological exposure. For instance, a nuclear-certified crane is
used to lower SCE devices into Ula tunnels and has been designated safety
significant due to the possibility of crane failure resulting in significant consequences
to the co-located worker. In some cases,
a man/small equipment lift is used to lower SCE devices into the Ula tunnels,
as opposed to the nuclear-certified crane.
While potential failure of the man-lift does not pose a high risk to the
public, failure of the man-lift is inherently dangerous with respect to the
facility worker. During staff-to-staff
discussions with BN, the Board’s staff learned that none of the hoisting and
rigging equipment underground in Ula has been designated safety class or safety
significant, including the man-lift.
A third example is the hoisting and rigging
equipment that is to be used in G-tunnel.
Again, during staff-to-staff
discussions, the Board’s staff learned that none of the hoisting and rigging
equipment that is to be used as part of G-tunnel’s mission is currently being
considered either safety significant or safety class. This equipment could potentially be used to
transport nuclear explosive devices, including damaged nuclear weapons and
improvised nuclear devices. Any failure
of the hoisting and rigging equipment while handling these devices or weapons
could result in severe consequences to the public and workers, including public
exposure to radioactive/hazardous materials.
Maintenance
Procedures. NTS does not appear to have an established
process to compare the maintenance recommendations of the manufacturer
(typically found in the equipment owner’s manual) to the facility’s maintenance
procedures for hoisting and rigging equipment.
Equipment maintenance and inspection requirements are credited as
reducing risk for some safety systems. The
manufacturer’s recommendations should be reviewed individually to determine if
a maintenance recommendation should be adopted as part of a routine inspection
program. If some of the manufacturer’s
recommendations are determined to be unnecessary, the rationale to exclude that
particular recommendation from the facility’s maintenance program should be
technically reviewed and documented.
Currently, the NTS hoisting and rigging
program does not utilize a systems engineering approach, in that no person or
group is responsible for tracking and trending equipment maintenance and
deficiencies. Such trending could be
used to help establish a predictive maintenance program to achieve increased
reliability.
Training
of Personnel. Training of hoisting and rigging personnel is,
in part, regulated by the local union. The union is requiring personnel involved in
hoisting and rigging to be certified through the Southern California Crane and
Hoisting Certification Program. Recertification is required every three years.
It appears that BN is appropriately
tracking the training certifications and certification expirations of the
hoisting and rigging personnel.