ML20058J957
| ML20058J957 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 12/09/1993 |
| From: | Hutchinson C ENTERGY OPERATIONS, INC. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GNRO-93-00151, GNRO-93-151, IEB-92-001, IEB-92-1, NUDOCS 9312140330 | |
| Download: ML20058J957 (9) | |
Text
-
Entergy Operations,Inc.
-ENTERGY me
.. mm Td riji 07 NK)
C. R. Hutchinson
- w. n,.y u
r i.v a, as F L e a s y rm December 9, 1993 U.S. Nuclear Regulatory Commiss(on, Mail Station P1-37 Washington, D.C.
20555 l
Attention:
Document Control Desk
Subject:
Grand Gulf Nuclear Station 4
Docket No. 50-416 License No. NPF-29 Use of a Video Camera to Satisfy the Requirement for Hourly Fire Watches of Thermo-Lag 330 Fire Barriers I
GNRO-93/00151 Gentlemen By letter dated June 24, 1992 the NRC issued Bulletin (NRCB) 92-01 to alert licensees to failures in fire endurance j
testing associated with the Thermo-Lag 330 fire barrier system.
This bulletin requested licensees to identify plant areas utilizing 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> and 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> rated Thermo-Lag 330 to protect wide cable trays and small conduits from fire damage.
i Supplement 1 to NRCB 92-01 was issued by letter dated August 28, 1992.
The supplement expanded the scope of the initial bulletin to encompass plant areas in which Thermo-Lag 330 fire barriers are used to protect raceways, walls, ceilings, equipment enclosures, and other areas to protect cable trays, conduits, or separate redundant safe shutdown divisions.
i Both the initial bulletin and supplement requested licensees f
to take certain immediate actions for plant areas utilizing Thermo-Lag 330 to protect safe shutdown capability.
Specifically, licensees were to implement in_accordance with plant procedures, the appropriate compensatory measures, such as fire watches, consistent with those measures which would normally be taken in accordance with the Technical Specifications or the operating license for an inoperable fire barrier.
The GGNS responses to NRCB 92-01 and NRCB 90-01 Supplement 1 were submitted by letters dated July 24, 1992 and September 25, 1992, respectively.
These letters provided a 1
0 G9312012 9312140330 931209
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gDR ADOCK 05000416 [I PDR ___ p l
December 9, 1993 I
GNRO-93/00151 Page 2 of 5 listing of the specific plant areas that are within the scope of the initial bulletin and the supplement.
Our responses
'I also stated that compensatory measures consisting of roving hourly fire watches were established per the GGNS fire protection program for the plant areas identified in our responses.
One of the plant areas identified in our responses as being within the scope of the initial bulletin and the supplement i
is designated as Fire Zone 1A539.
The roving hourly fire watch for this fire zone is being conducted by use of a video camera rather than by physical entry into the area to check i
for signs of fire.
The video camera was installed to preclude personnel hazards after a fire patrol received an OSHA reportable injury accessing this area to perform the fire watch patrol.
Attachmen2 1 provides a description of l
the injury, a general description of the area in question, justification for use of the video camera, and the postulated j
combustible loading for this particular fire zone.
Figure 1 shows the routes that a fire patrol would be required to follew to reach Fire Zone 1A539.
i With our commitment to retain fire watches in place until the operability of Thermo-Lag fire barriers is eatablished, accessing this area for an hourly fire watch presents a
)
personnel safety hazard.
Guidance received from NUMARC l
(References 1 and 2) encourages licensee
- to contact their licensing project manager or regdonel personnel to propose l
alternative compensatory measures for Thermo-Lag fire watches.
This guidance further states that the staff has i
permitted utilities to implement alternative compensatory measures for situations involving radiation exposure and personnel hazards.
Grand Gulf fire watch procedures generally require fire watch i
personnel to perform fire watch checks by physically entering the designated room (s) to check for any situation or circumstance that presents a possible fire hazard (e.g.
smoke, arcing / sparking, flames etc.).
As a minimum, room checks are required to be a general visual inspection of the l
room and at least one side of the fire barrier in question.
While we do not routinely use video cameras in lieu of traditional fire watches, it is GGNS's standard practice to l
utilize video cameras for performance of other functions (i.e.,
operational checks) in areas where personnel hazards are present.
2 l
G9312012 i
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i December 9, 1993 GNRO-93/00151 Page 3 of 5 A specific case citing the staff's position on this issue is delineated in a letter dated July 6, 1993 (Reference 3) where the staff responded to a request by Northeast Nuclear Energy Company (NNECO) to utilize video cameras in lieu of continuous fire watches for certain areas in it's Millstone Unit 1 plant containing Thermo-Lag 330.
The staff's response i
stated, in part that "the use of video Cameras is generally permitted in areas to mitigate overriding high radiation and ALARA concerns for the fire watches and in some cases, to
+
alleviate significant access problems".
l Although the NNECO request for use of video cameras in lieu i
of continuous fire watches was denied (NNECO's request was overly broad), from the resultant staff response and guidance from staff discussions with NUMARC, it is clear that personnel hazard is a criterion for which alternative 1
compensatory actions for performing fire watches are warranted.
Consistent with the staff's position in the NNECO example, we believe that use of a camera in this specific case is warranted based on personnel hazard encountered with performing the fire watch patrol in question.
l Should you require additional information concerning'this matter, please contact Charles E. Brooks at (601) 437-6555.
t Yours t ly, CRH/CEB/te3 attachmants:
1)
Supporting Information Details 2)
Fire Watch Route cc:
(See Next Page)
I i
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_u i
l December 9, 1993 t
GNRO-93/00151 Page 4 of 5 cc Mr. R. H. Bernhard (w/a) f' Mr. H. w. Keiser (w/a)
Mr. R. B. McGehoe (w/a) l Mr. N. S. Reynolds (w/a) j Mr. H. L. Thomas (w/o) i Mr. Stewart D. Ebneter (w/a)
Regional Administrator i
U.S. Nuclear Regulatory Commission Region II 101 Marietta St.,
N.W.,
Suite 2900 i
Atlanta, Georgia 30323 i
Mr.
P.
W.
O'Connor, Project Manager (w/2) i Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop 13H3 Washington, D.C.
20555 i
l i
l i
I l
G9312012
-4
6
.- to GNRO-93/00151 PERSONNEL HAZARD DESCRIPTION Fire Zone 1A539 is located on the roof of the Auxiliary Building at Elevation 185'-0".
It is situated at the northeast corner of the Auxiliary Building and adjacent to the south wall of the Control Building.
As depicted in Figure 1, this fire zone can be accessed from either the Auxiliary Building, (via Doors 1A502 or 1A504) or the Turbine Building (via Door IT501).
Access via Door 1A502 (shown as route 1 on the attached figure) from the Auxiliary Building to reach Fire Zone 1A539 requires the fire patrol to climb 3 steel grating steps, walk approximately 3 yards on an elevated steel grated platform, and then walk down 3 steel grating steps onto the roof of the Auxiliary Building.
The patrol would then be required to walk approximately 15 yards to reach Fire Zone 1A539.
Access via Door 1T501 (shown as route 2 on the attached figure) from the Turbine Building to reach Fire Zone 1A539 requires the fire patrol to step across a partial wall and walk approximately 25 yards to reach Fire Zone 1A539.
Access via Door 1A504 (shown as route 3 on the attached figure) from the Auxiliary Building to reach Fire Zone 1A539 requires the fire patrol to walk approximately 50 yards on the roof of the Auxiliary Building to reach Fire Zone 1A539.
Access to Fire Zone 1A539 through either route requires walking on the roof of the Auxiliary Building.
The external doors open against a pressure bank of sufficient magnitude to require significant effort, making them cumbersome to open and increasing the potential for an individual to lose balance control and possibly fall.
Although an anti-slip walk strip has been placed in the walk path, accumulations of moisture, bird droppings, moths, etc. present a significant fall hazard from slipping.
The personnel safety hazard is compounded while performing the hourly fire watch at night and during periods of inclement weather.
On July 24, 1992 a fire patrol slipped and fell in the metal' walkway while performing a fire watch tour on the roof of the Auxiliary Building (Fire Zone 1A539), chipping a bone in his left ankle.
This was an OSHA recordable accident, requiring the individual to be placed in 30 days restricted duty.
Earlier, on July 1, 1992 a fire patrol slipped and fell on the roof of the Auxiliary Building while performing this same patrol, although not sustaining an injury.
G9312012 - 6
, to GNRO-93/00151 AREA DESCRIPTION The interior dimensions of Fire Zone 1A539 are 46.5' (long) x 9. 0 ' (wide) x 19. 0 ' (high).
Its east, west, and south walls and l
ceiling are non-rated exterior barriers constructed of 2.0' thick reinforced concrete.
The floor and north wall are fire rated barriers; consequently, Fire Zone 1A539 is separated from f
adjacent areas in the Auxiliary Building by its 3-hour rated l
floor and from the Control Building by the 3-hour rated Auxiliary Building wall and a 3-hour rated Control Building wall.
Fire l
protection measures for this zone include automatic smoke detection and accessibility to portable extinguishers.
['
Fire Zone 1A539 contains Division I and II safe shutdown cables and raceways.
The Division II raceway consists of one six inch conduit and associated pull boxes.
The Division II raceway, associated raceway supports, and intervening steel is protected with 3-hour Thermo-Lag fire barriers.
The postulated fire duration in Fire Zone 1A539 is less than 60 minutes including transient combustibles.
The only postulated insitu combustible is 1EEE 383 qualified electrical cable.
A conservative cable tray fill of 60% was utilized to calculate the postulated fire duration.
Fire Zone 1A539 contains sixteen tray sections with actual cable fill ranging from 5% to 53% with an average actual tray fill of 29%.
If actual combustible loading were utilized to calculate a fire duration in the room, the postulated fire duration would be less than 30 minutes.
The postulated transient combustible for this zone consists of 100 square feet of fire retardant impregnated plywood.
Except for the electrical cables and raceway, Fire Zone 1A539 does not contain any equipment subject to mechanical failure with ensuing fires.
T The cameras installed in Fire Zone 1A539 is attached to the south wall of the room approximately ten feet above the floor.
The t
monitor is located on the 166'-0" Elevation of the Turbine Building.
The monitor includes controls allowing the camera to pan left-right and up-down to provide a better view of the room.
i If the camera were to fall, it could strike safety related electrical raceways (conduits); however, the czmera does not represent a seismic II/I hazard because it lacks sufficient mass to cause any damage (i.e.,
the camera weights less than 2 i
pounds).
CONCLUSION Fire Zone 1A539 does not contain materials or equipment which are likely to contribute to the occurrence of a rapidly developing and expanding fire.
The automatic smoke detection provided in this room is well suited for the respective fire hazard and G9312012 -7
i
. to GNRO-93/00151 provides high assurance that a fire will be detected promptly.
Due to the size of this room and low fire hazards, the plant fire brigade should be able to quickly access the seat of a fire for prompt extinguishment.
The camera meets the minimum procedural requirements to perform a visual inspection of the room.
Considering the physical separation from adjacent areas of the plant,-low fire hazard severity, available fire protection / detection and personnel hazards associated with conducting hourly fire watches on the roof of the Auxiliary Building, use of a camera to perform hourly visual inspections for signs of fire in Fire Zone 1A539 1s warranted.
REFERENCES 1)
Letter NUMARC to NUMARC Administrative Points of Contact, dated July 17, 1992 " Update on Thermo-Lag Fire Barrier Issue" 2)
Memorandum James G.
Partlow to All NRR Project Managers, dated June 25, 1992 "MPA X-201, NRC Bulletin 92-01, Failure of Thermo-Lag 330 Fire Barrier System to Maintain Cabling in Wide Cable Trays and Small Conduits Free from Fire damage" 3)
Letter USNRC to Northeast Nuclear Energy Company (Docket No.
l 50-245), dated July 6, 1993 " Milestone Nuclear Power i
Station, Unit 1 - Video Camera Request in Areas with Thermo-Lag 3 3 0 "
4)
NRC Bulletin 92-01, dated-June 24, 1992 " Failure of Thermo-Lag 330 Fire Barrier System to Maintain Cabling in Wide i
Cable Trays and Small Conduits Free From Fire Damage" 5)
Letter from W. T. Cottle (GGNS) to the USNRC, dated July 24, 1992 " Response to NRC Bulletin 92-01" 6)
NRC Bulletin 92-01 Supplement 1, dated August 28, 1992
" Failure of Thermo-Lag 330 Fire Barrier System to Perform
{
its Specified Fire Endurance Function" l
t 7)
Letter W.
T. Cottle (GGNS) to USNRC, dated September 25, 1992 " Response to NRC Bulletin 92-01 Supplement 1" 8)
Generic Letter 92-08, dated December 17, 1992 "Thermo-Lag 330-1 Fire Barriers" 9)
Letter C.
R. Hutchinson (GGNS) to USNRC, dated April 13, 1993 " Response to Generic Letter 92-08, Thermo-Lag 330-1 Fire Barriers" G9312012 - 8
Attochment 1 to GNRO-93/00151 REFERENCES (Continued) 10)
Letter Paul W. O'Connor (USNRC) to C. R. Hutchinson (GGNS),
dated May 17, 1993 " Grand Gulf Nuclear Station - Response to Generic Letter 92-08, Thermo-Lag 330-1 Fire Barriers" 11)
Letter M. J. Meisner (GGNS) to USNRC, dated June 22, 1993
" Response to NRC Generic Letter 92-08, Thermo-Lag 330-1 Fire Barriers, Additional Information" 12)
Letter NUMARC to NUMARC Administrative Points of Contact, dated July 8, 1992 "NRC Meeting.with NUMARC on Thermo-Lag Fire Barrier Issues" G9312012 -9
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