[Federal Register Volume 64, Number 203 (Thursday, October 21, 1999)]
[Notices]
[Pages 56815-56816]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-27496]


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NUCLEAR REGULATORY COMMISSION


Experts' Meeting on Jet Impingement Effects and Leak Rates From 
Steam Generator Tubes During Severe Accidents

AGENCY: Nuclear Regulatory Commission.

ACTION: Notice of meeting.

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SUMMARY: A meeting with a group of experts will be held at Argonne 
National Laboratory (ANL) to discuss information, data, and 
experimentation related to jet impingement effects and leak rates from 
degraded steam generator tubes under severe-accident conditions. Input 
from this meeting will be used to plan experimental and analytical work 
to be carried out under the Steam Generator Tube Integrity Research 
Program being conducted at ANL for the Nuclear Regulatory Commission 
(NRC). In the recent past, and expected to continue into the future, 
NRC has conducted and/or evaluated a number of risk analyses in 
conjunction with various actions related to steam generator tube 
integrity. Because risk from severe accidents can comprise a 
significant portion of the overall plant risk, the risk analyses have 
addressed the contribution from severe accidents. In conducting these 
analyses, the NRC staff has identified some areas that could benefit 
from additional data, modeling, and experimentation. In particular, we 
are interested in evaluating the possibility that the jet of 
superheated steam, hydrogen and entrained particles emanating from a 
cracked tube may penetrate the neighboring tube during severe-accident 
transients. In addition, we need to calculate the leak rate from tubes 
with throughwall cracks of various lengths under severe-accident 
conditions. In the absence of data on leak rates under the conditions 
of interest, one would need to calculate the crack opening areas under 
these conditions to estimate the leak rates. Besides information on the 
mechanical properties of Inconel tubes at the temperatures of interest, 
we need to know if (and how) creep and creep crack growth play a role 
in the crack opening areas developed under the time/temperature/
pressure exposures during severe accidents. Also, information is needed 
on whether the fluid escaping the crack will cause erosion of the crack 
walls, thereby increasing the crack opening areas. We have assembled a 
group of experts in the fields of high-temperature metallurgy, fracture 
mechanics, thermal hydraulics, severe-accident propagation, and 
erosion/corrosion to address these questions/issues during the meeting.
    If you are an expert in one or more of the above fields, and wish 
to participate and contribute to the meeting, you are asked to contact 
Dr. Dwight Diercks at ANL by no later than Thursday, November 11, 1999 
to provide him information for you to obtain access to the ANL site. 
Sufficient time is not available for citizens of sensitive countries, 
as listed in the DOE web site HTTP://WWW.DOE.GOV, to obtain clearance, 
and they will not be able to participate in this meeting.

DATES: November 19, 1999, from 8:30 a.m. to 5 p.m.

ADDRESSES: Argonne National Laboratory, Building 212, Room B201, 9700 
South Cass Avenue, Argonne, Illinois 60439.

FOR FURTHER INFORMATION CONTACT: Dr. Joseph Muscara, Mail Stop T10-E10, 
U.S. Nuclear Regulator Commission, Washington, DC 20555-0001. 
Telephone: (301) 415-5844; FAX: (301) 415-5074; Internet: [email protected].
    Or: Dr. Dwight Diercks, Argonne National Laboratory, 9700 South 
Cass Avenue, Argonne, Illinois 60439.

[[Page 56816]]

Telephone: (630) 252-5032; FAX: (630) 252-4798; Internet: 
[email protected].

    Dated at Rockville, Maryland, this 15th day of October, 1999.

    For the Nuclear Regulatory Commission.
Michael E. Mayfield,
Chief, Materials Engineering Branch, Division of Engineering 
Technology, Office of Nuclear Regulatory Research.
[FR Doc. 99-27496 Filed 10-20-99; 8:45 am]
BILLING CODE 7590-01-P