Information Notice No. 97-59: Fire Endurance Test Results of Versawrap Fire Barriers

                                UNITED STATES
                           WASHINGTON, D.C. 20555

                               August 1, 1997

                               FIRE BARRIERS


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


The U.S. Nuclear Regulatory Commission (NRC) is issuing this information
notice to alert addressees to the preliminary results of a recent fire
endurance test of a new fire barrier system.  No specific action or
written response is required.

Description of Circumstances

Transco Products, Incorporated, of Chicago, Illinois, is developing
Versawrap as a stand-alone fire barrier or as a potential upgrade for such
existing raceway fire barriers as Thermo-Lag 330-1 for use in nuclear
power plants to meet NRC fire protection regulations.  On April 7, 1997,
the NRC staff met with Entergy Operations, Incorporated, the licensee for
Arkansas Nuclear One, to discuss the use of Versawrap fire barriers to
protect redundant post-fire safe shutdown components.  Subsequently, on
April 10 and 11, 1997, the NRC staff witnessed a full-scale fire endurance
test of proposed 1-hour and 3-hour fire-rated Versawrap fire barriers at
Underwriters Laboratories, Incorporated (UL), of Northbrook, Illinois. 
The tests were also witnessed by representatives of Entergy Operations,
Incorporated, and Northern States Power Company.

The following summary of the test results is taken from the staff's trip

     Assuming that the thermocouples were working properly and on the
     basis of the printed temperatures at the end of about 61 minutes,
     it appeared that test articles A, B, C, D, L, O, and R met the
     maximum single point temperature rise acceptance criteria [of
     Generic Letter (GL) 86-10, Supplement 1, "Fire Endurance Test
     Acceptance Criteria for Fire Barrier Systems Used to Separate
     Redundant Safe Shutdown Trains Within the Same Fire Area"] for a
     1-hour fire rating while test articles E and Q did not.  Assuming
     that the thermocouples were working properly and on the basis of
     the printed temperatures at the end of about 2 hours and 55
     minutes (the temperatures at 3 hours were not

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                                                           August 1, 1997
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     printed), it also appeared that test articles F, G, H, and I may meet
     the maximum single point temperature rise acceptance criteria of
     GL 86-10, [Supplement 1], for a 3-hour fire rating, but test
     articles J, K, M, N, and P will not.

The observations made by the NRC staff during the fire endurance test are
not sufficient in and of themselves to determine whether or not Versawrap
fire barriers will meet NRC criteria for qualifying fire barriers.  In its
trip report, the staff also noted that UL would document the results of
the fire endurance test and that UL would base its conclusions regarding
the performance of the test articles on its observations during the fire
endurance and hose stream tests, analyses of electronically recorded
thermocouple data, and consideration of both the maximum single point
temperatures and the average unexposed side temperatures.  Review and
assessment of each of these factors are needed to determine whether the
barrier configurations that were tested meet the NRC acceptance criteria
specified in GL 86-10, Supplement 1.  To date, no licensee has submitted
the fire test results to the NRC for review.

The staff's meeting summary and trip report are available at the NRC
Public Document Room (Accession Numbers 9704188084 and 9705130324,

This information notice requires no specific action or written response. 
If you have any questions about the information in this notice, please
contact the technical contact listed below or the appropriate Office of
Nuclear Reactor Regulation (NRR) project manager.

                                         signed by S.H. Weiss for

                                   Marylee M. Slosson, Acting Director
                                   Division of Reactor Program Management
                                   Office of Nuclear Reactor Regulation

Technical contacts:  K.S. West, NRR                  

                     T.J. Carter, NRR

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