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. 99-160 FOR IMMEDIATE RELEASE

(Wednesday, July 28, 1999)

NRC PROPOSES TO AMEND REQUIREMENTS FOR

ONE SPENT FUEL STORAGE CASK DESIGN

The Nuclear Regulatory Commission is proposing to amend its

regulations to require inspection of certain welds and to specify

a minimum weld thickness for one spent nuclear fuel storage cask

design.

The amendment would implement a decision partially granting

a petition from the Toledo Coalition for Safe Energy and others.

It would affect the Vectra Technologies, Inc., NUHOMS-24P cask

intended for use at the Davis-Besse nuclear power plant 21 miles

from Toledo, Ohio.

Under NRC regulations, nuclear power plant licensees can use

cask designs with an NRC certificate of compliance listed in the

regulations to store spent fuel at the plants, under a general

license and without site-specific approval.

After an opportunity for public comment, the NRC in December

1994 added the Vectra standardized NUHOMS-24P and NUHOMS-52B to

the list of approved cask designs. Each NUHOMS system consists

of a sealed, dry, shielded canister that contains the spent fuel

assemblies. A loaded canister is stored inside a ventilated,

horizontal, concrete module.

The petition from Toledo Coalition for Safe Energy and

others raised concerns regarding the safety of the NUHOMS-24P

casks because of a reduction in the thickness of welds in the

walls of three canisters that had been fabricated for use at

Davis-Besse.

In a February 1997 decision, Carl Paperiello, Director of

NRC's Office of Nuclear Material Safety and Safeguards, found

that the minimum wall thickness measured by Vectra in the three

canisters was less than the original design wall thickness

specified in a company safety analysis report.
Vectra submitted calculations showing that its canister wall

thickness still met industry code requirements and NRC design

criteria.

The NRC Director's Decision said that, “while Vectra failed

to comply with its commitment of 0.625 inches, its failure

resulted in no compromise of safety. Nonetheless, the failure

raised an issue of poor control during the fabrication process."

Mr. Paperiello further found that the company's lack of

procedures to measure the final wall thickness in the area of the

welds did not provide adequate assurance that minimum wall

thickness was maintained. The decision said the Vectra

certificate of compliance should be modified to require a

fabrication inspection of the canister's welds.

The proposed changes would also reflect the transfer of the

certificate of compliance from Vectra Technologies, Inc. to

Transnuclear West, Inc. This action is in response to December

1997 letters from both companies describing the purchase by

Transnuclear West of Vectra’s intellectual properties and assets

associated with the NUHOMS technology.

Interested persons are invited to submit comments on the

proposed changes to the regulations within 75 days of a Federal

Register notice on this subject, expected shortly. Written

comments should be addressed to the Secretary, U.S. Nuclear

Regulatory Commission, Washington, DC 20555-0001, Attention:

Rulemakings and Adjudications Staff.

Comments may also be submitted electronically via the NRC's

interactive rulemaking web site at http://ruleforum.llnl.gov.

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