SAN FRANCISCO - Pacific Gas and Electric Company
today announced that it has identified and is working
to resolve conflicting documentation about the storage
location of a small amount of used nuclear fuel at
its Humboldt Bay Power Plant, near Eureka in Northern
California. The issue relates to records of the movement
of used nuclear fuel more than 34 years ago, and has
no impact on the health and safety of the public. The
amount of fuel in question consists of three, half-inch
diameter by 18-inch long segments, weighing a total
of about 4 pounds, which were cut from a single, seven-foot
fuel rod in 1968.
Plant records indicate that these segments may have
been shipped offsite in 1969, as part of a larger shipment
of used fuel sent for reprocessing. However, recently
reviewed documents indicate the fuel may have remained
stored safely underwater since 1968, in the plant's
used fuel pool, where other used nuclear fuel is stored.
Plant employees are now in the process of retrieving
and examining additional records, as well as meticulously
searching the contents of the used fuel pool, to determine
which document is accurate.
"The fuel rod segments remain in the used fuel pool,
or were shipped offsite to an appropriate, controlled
facility - either for analysis or reprocessing," said
Greg Rueger, senior vice president for generation and
Chief Nuclear Officer for the utility. "However, we
must ensure we have accurate records, and that entails
a meticulous search of the pool itself, to confirm
the location of these three used fuel segments."
In the late 1960's up to the mid-1970's, nuclear power
plants were permitted to ship used nuclear fuel offsite
for reprocessing to be used again. The fuel in question
would have gone to the Nuclear Fuel Services reprocessing
facility, located in West Valley, New York. The Humboldt
power plant, which opened in 1963, ceased operations
in 1976. No fuel has been shipped offsite since 1974.
The security in place at the Humboldt plant now and
throughout its existence adds to the strong belief
that the fuel was either appropriately shipped offsite,
or stored in the pool. There is no way these used fuel
segments could have been removed inappropriately from
the site without detection by an extensive array of
radiation monitors. Further, to be handled safely,
the segments would have to be encased in a steel-and-lead
container weighing nearly one ton, and could only have
been moved with special handling equipment designed
for this purpose.
Since late 2003, PG&E plant personnel have been
in the process of conducting a meticulous search of
the plant's records, and verifying and characterizing
the contents of the used fuel pool, in preparation
for the upcoming decommissioning of the plant and movement
of the used fuel pool contents to dry cask storage.
On June 23, 2004, while undertaking this review, PG&E
personnel discovered the first indication of a discrepancy
in documentation, as they reviewed minutes of the plant's
On-Site Review Committee (OSRC) meetings from 1968.
Those minutes revealed one fuel rod had been removed
from a fuel assembly and three approximately 18-inch-long
segments were cut from it. (Fuel rods, which are about
seven feet long, are typically secured in what is called
a fuel assembly, which in this case consists of 49
fuel rods.) These three segments were to be shipped
offsite for analysis at the Battelle Laboratory in
Columbus, Ohio in September 1968. However, these OSRC
minutes further indicate the shipment was cancelled
and the three fuel segments, along with the remnants
of the cut fuel rod, did not leave the Humboldt plant
and were returned to the used fuel pool. The documents
note that the remnants of the cut rod were deposited
in the pool's main (central) storage container (used
to store miscellaneous irradiated components), but
the exact location in the pool of the three segments
was not identified.
These 1968 OSRC minutes conflict with the plant's
current used fuel inventory, which does not identify
this fuel rod as being located at the plant. In fact,
documentation was reviewed on June 25, 2004, which
indicates that the entire fuel assembly was shipped
offsite for reprocessing at the West Valley facility
on August 6, 1969. This shipping record does not indicate
that one fuel rod had been removed from the assembly.
It is now considered likely that this record is not
complete, and the fuel assembly was shipped in 1969
without the fuel rod in question.
Further review of records did not resolve this discrepancy,
so on June 28, PG&E verbally notified the Nuclear
Regulatory Commission (NRC) Region IV office of the
Plant personnel have continued to review records,
and on July 7, began a physical search of the used
fuel pool focused on locating the segmented fuel rod
in question. The pool, which is from 26 to 30 feet
deep and 22 feet wide by 28 feet long, must be searched
slowly and methodically, using underwater cameras and
remote-controlled tools on long poles. There are 390
used fuel assemblies stored in the pool, with numerous
spaces between and around them. In addition, there
are six storage containers filled with various irradiated
hardware and components. Each of these storage containers
must be emptied piece-by-piece to conduct a full search
for the fuel segments. They are 8 feet long and range
in dimension from four to about nine inches square.
Two of these containers, including the main storage
container, have been searched and their contents inventoried.
On July 9-11, 2004, this search appears to have verified
that the remnants of the cut fuel rod in question are
located in the main storage container, as indicated
in the OSRC minutes. In an effort to verify that the
three 18-inch segments are also in the pool, the physical
search is continuing.
"It may take several more weeks to finish an exhaustive
review of the appropriate docu顱ments from the 1960's
and conduct a full search of the pool, but we are putting
significant effort into resolving this discrepancy
as quickly as possible. We want there to be no question
about how seriously we take our responsibility to safely
store used fuel," Rueger said.
PG&E has continuously updated the NRC on the status
of the investigation, and regional NRC personnel have
inspected the site and are monitoring progress.
PG&E is continuing its documentation search, and
has begun interviewing current and former plant personnel
who worked at the plant as far back as 1967. The utility
is requesting Nuclear Fuel Services, Inc. and the Battelle
Laboratory provide access to their records, for this
The investigation could take several more weeks to
complete, largely because of the difficulty associated
with physically searching the used fuel pool.