ML032520821

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS

WASHINGTON, D.C. 20555

October 6, 2003

NRC INFORMATION NOTICE 2003-16: ICING CONDITIONS BETWEEN BOTTOM OF

DRY STORAGE SYSTEM AND STORAGE PAD

Addressees:

All 10 CFR Part 72 licensees and certificate holders.

Purpose:

The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice to apprise 

addressees of an icing condition at an independent spent fuel storage installation (ISFSI) that

placed the dry spent fuel storage systems into an unanalyzed condition. It is expected that

recipients will review the information for applicability to their facilities and consider actions, as

appropriate, to address the potential issue. However, suggestions contained in this information

notice are not new NRC requirements; therefore, no specific action nor written response is

required.

Description of Circumstances:

In February 2003, Maine Yankee Atomic Power Company (MYAPC) discovered that the surface

area between the storage system vertical concrete casks (VCCs) and the concrete ISFSI

storage pad had a significant covering of ice (approximately 80 - 95 percent of the surface). 

The design basis for the NAC-UMS dry spent fuel storage system used by MYAPC at the Maine

Yankee ISFSI did not specifically address ice formation between the bottom of the VCC and the

pad during storage operations. The icing condition created a different operating parameter

than those presented in the NAC-UMS Final Safety Analysis Report (FSAR).

Discussion:

On January 7, 2003, while MYAPC was moving an empty VCC on the heavy-haul trailer from a

storage area up an incline to the fuel handling building, the VCC unexpectedly slid

approximately 0.6 meters (2 feet) toward the rear of the trailer. The licensee immediately

stopped work and investigated the cause for the VCC sliding. During the transfer operation, the

VCC was resting on an inactivated air pad and positioned approximately in the center of the

heavy-haul trailer. The root cause was determined to be the presence of ice between the air

pad and the bottom of the VCC. To determine the extent of this condition, MYAPC lifted six

additional VCCs and examined the bearing surfaces of the VCCs and the ISFSI pad. The

licensee examined a variety of VCC parameters to see if any patterns developed. The MYAPC

review took into account the VCC’s manufacturers, VCCs with north and south sun exposure,

loaded and empty VCCs, and one empty VCC with a sheet of linoleum placed between the

VCC and concrete pad.
IN 2003-16

Page 2 of 2

The licensee found that approximately 80 - 95 percent of the VCC-bearing surfaces were

consistently covered with a layer of ice ranging from 1.5- to 6.4-mm (0.06- to 0.25-inches) thick. 

All the VCCs had a clean central surface area ranging from 0.5 to 1.4 m2

 (5 to 15 ft2) and all the

VCCs had a considerable buildup of ice around the outer diameter.

The NAC-UMS Certificate of Compliance states that the design basis site-specific parameters

and analysis that require verification by MYAPC include physical testing to demonstrate that the

coefficient of friction between the VCC and the ISFSI pad surface is at least 0.5. However, the

significant icing condition of the bearing surfaces of the VCCs indicated that the coefficient of

friction may not be 0.5.

Conclusion:

The icing condition identified at Maine Yankee could potentially occur at other ISFSI sites using

free-standing ventilated concrete cask designs (e.g., VSC-24, NAC-UMS, NAC-MPC, 

HI-STORM, and FuelSolutions) located in the northern regions of the country. This information

notice is to inform licensees of this potential icing condition. NRC expects licensees to assess

their particular ISFSIs for a similar condition and to take appropriate actions, if necessary.

This information notice requires no specific action nor written response. If you have any

questions about the information in this notice, please contact the technical contact listed below

or the appropriate regional office.

/RA/

E. William Brach, Director

Spent Fuel Project Office 

Office of Nuclear Material Safety

 and Safeguards

Technical Contact: Stephen O’Connor, NMSS 

(301) 415-8561

E-mail: sco@nrc.gov

Attachments:

1. List of Recently Issued NRC Information Notices

2. List of Recently Issued NMSS Information Notices
____________________________________________________________________________________

OL = Operating License

CP = Construction Permit

Attachment 1

IN 2003-16

Page 1 of 1

LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

____________________________________________________________________________________

Information Date of 

Notice No. Subject Issuance Issued to

____________________________________________________________________________________

2003-15 Importance of Followup

Activities in Resolving

Maintenance Issues

09/05/2003 All holders of operating licenses

for nuclear power reactors except

those who have permanently

ceased operation and have

certified that fuel has been

permanently removed from the

reactor vessel.

2003-14 Potential Vulnerability of Plant

Computer Network to Worm

Infection

08/29/2003 All holders of operating licenses

for nuclear power reactors,

except those who have

permanently ceased operations

and have certified that fuel has

been permanently removed from

the reactor vessel. 

2003-13 Steam Generator Tube

Degradation at Diablo Canyon

08/28/2003 All holders of operating licenses

for pressurized-water reactors

(PWRs), except those who have

permanently ceased operations

and have certified that fuel has

been permanently removed from

the reactor.

89-69, Sup 1 Shadow Corrosion Resulting in

Fuel Channel Bowing

08/25/2003 All holders of operating licenses

for boiling water reactors (BWRs),

except those who have

permanently ceased operations

and have certified that fuel has

been permanently removed from

the reactor vessel. 

Note: NRC generic communications may be received in electronic format shortly after they are

issued by subscribing to the NRC listserver as follows:

To subscribe send an e-mail to <listproc@nrc.gov >, no subject, and the following

command in the message portion:

subscribe gc-nrr firstname lastname
____________________________________________________________________________________

OL = Operating License

CP = Construction Permit

Attachment 2

IN 2003-16

Page 1 of 1

LIST OF RECENTLY ISSUED

NMSS INFORMATION NOTICES

____________________________________________________________________________________

Information Date of 

Notice No. Subject Issuance Issued to

____________________________________________________________________________________

2003-12 Problems Involved in

Monitoring Dose to the Hands

Resulting from the Handling of

Radiopharmaceuticals

08/22/2003 All holders of 10 CFR Parts 32,

33, and 35 licenses.

2003-10 Criticality Monitoring System

Degradation at BWX

Technologies, Inc., Nuclear

Products Division, Lynchburg,

VA

08/04/2003 All U.S. Nuclear Regulatory

Commission (NRC) licensees

authorized to possess a critical

mass of special nuclear material.

2003-09 Source Positioning Errors and

System Malfunctions During

Administration of Intravascular

Brachtherapy

07/16/2003 All medical licensees.

2002-31, Sup 1 Potentially Defective UF6

Cylinder Valves (1-inch)

03/24/2003 All U.S. Nuclear Regulatory

Commission (NRC) licensees

authorized to possess and use

source material and/or special

nuclear material for heating,

emptying, filling, or shipping 30-

and 48-inch cylinders of uranium

hexafluoride (UF6).

2002-36 Incomplete or Inaccurate

Information Provided to the

Licensee and/or NRC By Any

Contractor or Subcontractor

Employee

12/27/2002 All materials and fuel cycle

licensees and certificate holders.

2002-35 Changes to 10 CFR Parts 71

and 72 Quality Assurance

Programs

12/20/2002 All holders of 10 CFR Part 71

quality assurance program

approvals and all 10 CFR Part 72

licensees and certificate holders

Note: NRC generic communications may be received in electronic format shortly after they are issued by

subscribing to the NRC listserver as follows:

To subscribe send an e-mail to <listproc@nrc.gov >, no subject, and the following command in the

message portion:

subscribe gc-nrr firstname lastname