United States Nuclear Regulatory Commission - Protecting People and the Environment

Information Notice No. 90-52: Retention of Broken Charpy Specimens

                                UNITED STATES
                        NUCLEAR REGULATORY COMMISSION
                    OFFICE OF NUCLEAR REACTOR REGULATION
                           WASHINGTON, D.C.  20555

                               August 14, 1990


Information Notice No. 90-52:  RETENTION OF BROKEN CHARPY SPECIMENS 


Addressees:

All holders of operating licenses or construction permits for nuclear power 
reactors. 

Purpose:

This information notice is intended to alert addressees to the potential 
value of the broken Charpy specimens and other test materials from their 
reactor vessel material surveillance program.  It is expected that 
recipients will review the information for applicability to their facilities 
and consider appropriate actions.  However, suggestions contained in this 
information notice do not constitute NRC requirements; therefore, no 
specific action or written response is required. 

Description of Circumstances:

The NRC has received information that, in order to avoid the costs and 
burden of long-term storage of such irradiated materials, some licensees are 
discarding broken Charpy specimens and other surveillance materials 
remaining from surveillance test programs conducted years ago.  However, 
broken Charpy specimens, particularly those from reactor vessels having 
radiation sensitive materials, may provide useful information such as 
specific material embrittlement data.  Without specific data, the 
alternative for the licensee is often the imposition of conservative 
assumptions. 

Discussion:

Charpy specimens may be reconstituted by trimming off the fractured ends and 
then welding end tabs onto the broken halves.  Although this fabrication 
process involves problems such as assuring proper alignment and temperature 
control in the center region where the new notch is to be placed, the 
technology of reconstituting broken Charpy specimens is sufficiently 
developed to permit the writing of ASTM E 1253-88, "Standard Guide for 
Reconstitution of Irradiated Charpy Specimens."  An ASTM Committee E-10 
workshop on the techniques for reconstitution is scheduled for January 1991 
and is expected to provide a basis for updating the Guide.  




9008080246 
.

                                                            IN 90-52
                                                            August 14, 1990
                                                            Page 2 of 2


Some broken Charpy specimens consist of unique material.  Depending on lead 
factors and the time of withdrawal, the fluence exposure may be fairly 
representative of the fluence at the 1/4 t and 3/4 t locations in the vessel 
wall near the end of the operating license period.  When reconstituted, 
these specimens should provide extremely useful information for a 
surveillance program regarding a license renewal period or for the 
determination of the degree of annealing recovery and the rate of 
reembrittlement.  Furthermore, tests of reconstituted Charpy specimens might 
provide needed measurements of the level of embrittlement for use in the 
pressurized thermal shock (PTS) studies required by Regulatory Guide 1.154. 

This information notice requires no specific action or written response.  If 
you have any questions about the information in this notice, please contact 
one of the technical contacts listed below or the appropriate NRR project 
manager. 




                              Charles E. Rossi, Director 
                              Division of Operational Events Assessment
                              Office of Nuclear Reactor Regulation 


Technical Contacts:  Pryor N. Randall, NRR
                     (301) 492-1311 

                     Keith R. Wichman, NRR 
                     (301) 492-0757


Attachment:  List of Recently Issued NRC Information Notices 
.ENDEND
Page Last Reviewed/Updated Tuesday, November 12, 2013