IE Circular No. 78-34 - Installation Error That Could Prevent Closing of Fire Doors
CR78004
May 15, 1978
MEMORANDUM FOR: B. H. Grier, Director, Region I
J. P. O'Reilly, Director, Region II
J. G. Keppler, Director, Region III
G. L. Madsen, Acting Director, Region IV
R. H. Engelken, Director, Region V
FROM: Harold D. Thornburg, Director, Division of Reactor
Operations Inspection, Office of Inspection and
Enforcement
SUBJECT: IE CIRCULAR 78-34 - INSTALLATION ERROR THAT COULD
PREVENT CLOSING OF FIRE DOORS
The subject circular is transmitted for issuance by close of business within
three days after date of this letter. The circular should be issued to all
holders of Reactor Operating Licenses or Construction Permits. Also enclosed
is a draft copy of the transmittal letter.
/S/ Karl V. Seyfrit/for
Harold D. Thornburg, Director
Division of Reactor Operations
Inspection
Office of Inspection and Enforcement
Enclosures:
1. Draft Transmittal Letter
2. IE Circular 78-04
CONTACT: D. C. Kirkpatrick, IE
49-28180
.
May , 1978
(Transmittal letter for IE Circular 78-04, to each holder of an NRC
Operating License or Construction Permit.)
IE Circular No. 78-04
Addressee:
The enclosed IE Circular No. 78-04, is forwarded to you for information. No
written response is required. Should you have any questions related to your
understanding of this matter, please contact this office.
Sincerely,
Signature
(Regional Director)
Enclosures:
1. IE Circular No. 78-04
2. List of IE Circulars
Issued in 1978
.
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF INSPECTION AND ENFORCEMENT
WASHINGTON, D. C. 20555
May 15, 1978
IE Circular No. 78-04
INSTALLATION ERRORS THAT COULD PREVENT CLOSING OF FIRE DOORS
During a quality assurance audit, Georgia Power Company personnel discovered
three types of installation errors on sliding fire door closers at the Hatch
Nuclear Station that could have prevented the functioning of the doors.
The mechanism involved are D and H Pyromatic door closers manufactured by
Mesker (see attached drawing). Each unit is powered by a suspended weight
which rotates a pulley arrangement to draw the fire door closed. Closure is
normally prevented by a fuse link cord which acts through a lever arm. This
device, called the "fuse link anchor hook," prevents rotation of the
pulleys, unless the fuse links are severed by fire.
The first improper installation was the replacement of the combustible fuse
cords by "S-Hook" type chain. The replacement was necessary due to random
failures of the original fuse link cord. However, the cord (or chain) passes
through an opening in the case containing the mechanism, and the S links
tended to spring open and catch on the edges of this opening. This problem
was aggravated in some instances by the lack of guide bushings which are
normally installed to facilitate the passage of the chain through the
opening.
Another error discovered was the mispositioning of the fuse link anchor
hook. Following severance of the fuse link, the pulleys rotate clockwise and
a correctly installed anchor hook is rotated through an angle that permits
the terminal eye on the end of the fuse link cord to fall free. This
prevents the cord (or chain) and the remains of the fuse link assembly from
becoming entangled in the rotating mechanism. However, some anchor hooks
were found to be installed with the curved section extending to the left
(relative to the front view shown). This position can cause the terminal eye
to remain hooked during rotation, instead of falling free. These errors
actually caused the jamming of fire door closers during tests that followed
their discovery.
The corrective actions were to replace the "S" type chain with flat sash
chain, install the missing bushings and to correctly orient the fuse link
anchor hooks.
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IE Circular No. 78-04 May 15, 1978
It is recommended that all holders of reactor operating licenses and
construction permits determine if any fire door closers of this type are
installed in their facility(ies). If this is the case, it should be verified
that they are installed in accordance with the manufacturers design and that
improper installations, such as described herein, do not exist.
This circular is being distributed for information, and no reply is
requested. If you require any additional information regarding this matter,
please contact the director of this NRC Regional Office.
Attachment:
Drawing No. R-4174
D&H Pyromatic Door Closer
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