Information Notice No. 96-53: Retrofit to Amersham 660 Posilock Radiography Camera to Correct Inconsistency in 10 CFR Part 34 Compatibility

                                     UNITED STATES
                             NUCLEAR REGULATORY COMMISSION
                   OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS
                                 WASHINGTON, DC  20555

                                   October 15, 1996


NRC INFORMATION NOTICE 96-53:  RETROFIT TO AMERSHAM 660 POSILOCK
                               RADIOGRAPHY CAMERA TO CORRECT
                               INCONSISTENCY IN 10 CFR PART 34
                               COMPATIBILITY


Addressees

All industrial radiography licensees.

Purpose

The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice to make
licensees aware of a scenario where the Amersham model 660 Posilock radiography camera
would not pass the horizontal shock test as required by 10 CFR Part 34, and of a retrofit to
the Amersham Model 660 Posilock radiography camera to correct that problem.  It is
expected that recipients will review the information for applicability to their licensed activity. 
However, suggestions contained in this information notice are not new NRC requirements;
therefore, no specific action nor written response is required.

Description of Circumstances

Recently, NRC became aware of a scenario where the Amersham Model 660 Posilock
radiography camera would not pass the horizontal shock test as required by 10 CFR 
Part 34.20, "Performance Requirements for Radiography Equipment."  Amersham was made
aware of the test results, and took action to correct the situation.

Discussion

When Amersham tested the camera in accordance with ANSI N432-1980 in 1989, the target
for the horizontal shock test was a point between the two bumpers, directly at the slide lock. 
This point was chosen by Amersham as the most vulnerable impact site.  In 1995, tests
performed as part of an independent testing contract revealed that there was a more
vulnerable impact site.  The contractor�s test focused aiming at one of the bumpers.  The 
result was damage to the bumper, causing the bumper to become detached, thereby
exposing the lock slide to direct impact.  Subsequent impacts then broke the lock slide. 
There appear to be no significant safety issues, since breaking the lock slide would result in
an inability to open the shutter.  If the source were in the exposed position at the time of
impact, the source could still be returned to the shielded and secured position.


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                                                                   October 15, 1996
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As a result of the test information, Amersham redesigned the bumpers.  The modified
bumpers contain a metal core that distributes the stress of an impact to the end plate.  
Amersham states that the camera with the modified bumpers passed the horizontal shock
test, where the test was aimed at the bumper.  The bumpers remained intact, and although
they showed signs of impact, they still protected the lock slide.  Amersham states that it sent
retrofit kits to all owners, of potentially affected cameras, on record with them.  Attachment 1
contains a copy of the retrofit kit letter and bumper replacement instructions.  The retrofit will
be differentiated by the use of a non-Phillips head screw instead of the Phillips head screw
currently in use.  Cameras with the retrofit would continue to meet the requirements of 10
CFR Part 34.

All affected cameras should be retrofitted as soon as possible.  Licensees should contact
Amersham to obtain retrofit kits or assistance with retrofit procedures, or to notify Amersham
if they have not received their kit.  Affected cameras may be checked for completed retrofit
during any inspection.

Licensees possessing these cameras should be aware of this issue and take action
appropriately.

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. 




                                               Donald A. Cool, Director 
                                               Division of Industrial and 
                                                 Medical Nuclear Safety
                                               Office of Nuclear Material Safety
                                                 and Safeguards

Technical contact:  Michele Burgess, IMAB
                    (301) 415-5868
                    Email:  mlb5@nrc.gov
(An electronic copy of Attachment 1, "Amersham Retrofit Kit Letter and Bumper Replacement
Instructions," was not available.)