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NRC NEWS
U. S. NUCLEAR REGULATORY COMMISSION |
| Office of Public Affairs |
Telephone: 301/415-8200 |
| Washington, DC 20555-001 |
E-mail: opa@nrc.gov |
No. 96-95 FOR IMMEDIATE RELEASE
(Friday, July 5, 1996)
NRC STAFF ASKS FOR INFORMATION, ACTION ON SPENT FUEL CASKS
IN LIGHT OF RECENT INCIDENT AT POINT BEACH PLANT
The Nuclear Regulatory Commission staff has issued a bulletin
seeking information about the potential for chemical, electro-chemical or
other reactions which might adversely affect the safety of spent fuel
storage or transportation casks.
The bulletin is being sent to all nuclear power plant licensees, to
holders of and applicants for spent fuel storage and transportation cask
certificates of compliance, to companies which sell such casks, and to
all registered users of spent fuel transportation casks.
Responses are required within 45 days from licensees with
independent spent fuel storage installations (such as dry cask storage
units); from all companies selling the casks; and from holders of
certificates of compliance.
NRC is issuing the bulletin as the result of a hydrogen burn that
occurred May 28 while technicians at the Point Beach nuclear power plant
in Wisconsin were welding a shield lid on a spent fuel storage cask.
Pressure from the ignitiion of the hydrogen displaced the 6390-pound lid,
leaving it with one edge tipped about three inches higher than normal.
Both an NRC augmented inspection team and Wisconsin Electric Power Co.
concluded that the hydrogen was generated by a chemical reaction between
zinc in a coating on the cask interior and acidic borated water from the
plant spent fuel pool, which was in the cask.
After the incident, Wisconsin Electric, along with utilities using
or planning to use the same cask model (Sierra Nuclear VSC-24) at the
Arkansas Nuclear One plant in Arkansas and at the Palisades plant in
Michigan, agreed to assess the hazards and to take special precautions
before loading or unloading these casks. They also have agreed not to
load or unload a VSC-24 cask or to place one into their spent fuel pools
until NRC staff has reviewed and sanctioned their responses and has
verified later actions they may take in response to the bulletin. NRC
confirmed these commitments in writing.
The bulletin requires that spent fuel storage facility licnesees,
cask vendors, and compliance certificate holders take these actions:
. Determine whether chemical, electro-chemical or other
reactions can occur during any phase of spent fuel cask
loading, unloading, handling, storage or transportation, and
what adverse effects they might have on the casks and their
contents.
. Review current procedures with the view of minimizing
potentially hazardous conditions.
. See if any chemical, electro-chemical or other reactions have
occurred in casks presently loaded with spent fuel, and, if
so, determine what effect these reactions have had on the
integrity of the cask and the retrievability of the fuel.
Additionally, NRC requests these actions from the cask vendor,
Sierra Nuclear Corporation, and from utilities using the Sierra VSC-24
cask at the Arkansas Nuclear One, Palisades and Point Beach plants:
. Evaluate the effects of a reaction among the interior zinc
coating and water environments the cask may encounter, and
show that the cask's integrity and fuel's retrievability will
not be adversely affected over a 20-year period.
. Justify the continued use of VSC-24 storage casks already
loaded with spent fuel.
. Evaluate cask unloading procedures to consider the likely
presence of hydrogen gas and its possible adverse effects on
cask handling and performance, and then inform NRC of any
procedure changes.
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EDITORS: Copies of the full text of the bulletin are available
from the NRC Office of Public Affairs. It also has
been posted on the internet at this address:
http://www.nrc.gov/RIII/rjs2/reports.
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