United States Nuclear Regulatory Commission

Office of Public Affairs

Washington, DC 20555

Phone 301-415-8200 Fax 301-415-2234

Internet: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 VSC24) 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:

ˇ 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.

ˇ Review current procedures with the view of minimizing

potentially hazardous conditions.

ˇ 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:

ˇ 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.

ˇ Justify the continued use of VSC-24 storage casks

already loaded with spent fuel.

ˇ 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.

####

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.