ML031010619
| ML031010619 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 04/11/2003 |
| From: | Marschall C NRC/RGN-IV/DRS/EMB |
| To: | Anderson C Entergy Operations |
| References | |
| EA-03-016, FOIA/PA-2003-0358 IR-01-006 | |
| Download: ML031010619 (68) | |
See also: IR 05000313/2001006
Text
April 11, 2003
Craig G. Anderson, Vice President,
Operations
Arkansas Nuclear One
Entergy Operations, Inc.
1448 S.R. 333
Russellville, Arkansas 72801-0967
SUBJECT:
ARKANSAS NUCLEAR ONE - NRC TRIENNIAL FIRE PROTECTION
INSPECTION REPORT 50-313/01-06; 50-368/01-06 - RESPONSE TO
REQUEST FOR ADDITIONAL INFORMATION
Dear Mr. Anderson:
In a letter dated March 25, 2003, the NRC informed you that the finding discussed in the
subject inspection report was preliminarily determined to be Greater-Than-Green (i.e., a finding
whose safety significance is greater than very low). As stated in our March 25, letter, you were
provided with the opportunity to present your position on the finding to the NRC at a Regulatory
Conference or in writing, before a final decision on the significance of this finding is reached. In
a subsequent phone conversation, you informed us of your preference to present your position
at a Regulatory Conference.
As an enclosure to our letter of March 25, 2003, we provided you a summary of our Phase 3
significance determination evaluation. In a letter dated April 2, 2003, you stated that additional
information was necessary to ensure a productive exchange of information at the Regulatory
Conference. In Attachment 1 of that letter, you provided four specific information requests
concerning our significance determination evaluation. In response to Item 1 of this request,
enclosed is a copy of the fire modeling of Fire Zones 98-J and 99-M, which we used in our
Phase 3 significance determination of the finding. In determining the significance of this
finding, we started with your Phase 3 significance evaluation and modified certain aspects of it
to better assess the significance of the finding. Troy Pruett of NRC Region IV discussed these
changes with Mike Cooper and Jessica Walker of your staff. In Enclosure 2 we are providing to
you our Phase 3 significance determination analysis, which in conjunction with the
aforementioned discusion between your staff and Troy Pruett should satisfy Items 2 and 3 of
your Attachment 1. The information requested in Item 4 is addressed in the Significance
Determination Process Phase 3 Summary, which is an enclosure to our March 25, 2003 letter.
If you have any further questions, you may contact me at 817-860-8185.
Entergy Operations, Inc.
-2-
In accordance with 10 CFR 2.790 of the NRCs Rules of Practice, a copy of this letter
and its enclosures will be available electronically for public inspection in the NRC Public
Document Room or from the Publicly Available Records (PARS) component of NRCs
document system (ADAMS). ADAMS is accessible from the NRC Web site at
http://www.nrc.gov/reading-rm/adams.html (the Public Electronic Reading Room).
Sincerely,
/RA/
Charles S. Marschall, Chief
Engineering and Maintenance Branch
Division of Reactor Safety
Dockets: 50-313; 50-368
Enclosures:
1.
Fire Modeling of Fire Zone 98-J, Emergency Diesel Generator Corridor and 99-M, North
Electrical Switchgear Room, Arkansas Nuclear One - Unit 1
2.
Phase 3 SDP Analysis: Arkansas Nuclear One, Unit 1
cc:
Executive Vice President
& Chief Operating Officer
Entergy Operations, Inc.
P.O. Box 31995
Jackson, Mississippi 39286-1995
Vice President
Operations Support
Entergy Operations, Inc.
P.O. Box 31995
Jackson, Mississippi 39286-1995
Manager, Washington Nuclear Operations
ABB Combustion Engineering Nuclear
Power
12300 Twinbrook Parkway, Suite 330
Rockville, Maryland 20852
County Judge of Pope County
Pope County Courthouse
100 West Main Street
Russellville, Arkansas 72801
Entergy Operations, Inc.
-3-
Winston & Strawn
1400 L Street, N.W.
Washington, DC 20005-3502
Bernard Bevill
Radiation Control Team Leader
Division of Radiation Control and
Emergency Management
4815 West Markham Street, Mail Slot 30
Little Rock, Arkansas 72205-3867
Mike Schoppman
Framatome ANP, Inc.
Suite 705
1911 North Fort Myer Drive
Rosslyn, Virginia 22209
Entergy Operations, Inc.
-4-
Electronic distribution by RIV:
Regional Administrator (EWM)
Deputy Regional Administrator (TPG)
DRP Director (ATH)
DRS Director (DDC)
Deputy Director, DRP (GMG)
Branch Chief, DRP/D (LJS)
Branch Chief, DRS/EMB (CSM)
Senior Resident Inspector (RLB3)
Senior Project Engineer, DRP/D (JAC)
Staff Chief, DRP/TSS (PHH)
RITS Coordinator (NBH)
K. Smith, Region IV (KDS1)
G. Sanborn, D:ACES, Region IV (GFS)
M. Vasquez, ACES, Region IV (GMV)
W. Maier, Region IV (WAM)
S. Morris, OEDO, RIV Coordinator (SAM1)
B. McDermott, OEDO (BJM)
R. Larson, OEDO (RKL)
J. Hannon, NRR (JNH)
L. Dudes, NRR (LAD)
T. Alexion, NRR (TWA)
J. Dixon-Herrity, OE (JLD)
OEMAIL
DOCUMENT: R:\\_ano\\2001\\an0106response-rln.wpd
RIV:DRS/EMB
C:DRS/EMB
RLNease/lmb
CSMarschall
/RA/
/RA/
4/11/03
4/11/03
OFFICIAL RECORD COPY
T=Telephone E=E-mail F=Fax
ENCLOSURE 1
Fire Modeling of Fire Zone 98-J, Emergency Diesel Generator Corridor and
99-M, North Electrical Switchgear Room
Arkansas Nuclear One - Unit 1
SUMMARY
Fire modeling of the Fire Zones 98J, Emergency Diesel Generator Corridor and 99-M, North
Electrical Switchgear Room have been performed to evaluate the potentially hazardous
conditions (increased temperature and smoke layer level) that could be caused by a fire and
assess the associated damage potential to cables or equipment of redundant trains of systems
for safe shutdown. The multi-zone fire model CFAST (Consolidated Model of Fire Growth and
Smoke Transport) was used to evaluate the different fire scenarios in the Emergency Diesel
Generator Corridor and North Electrical Switchgear Room.
IGNITION SOURCES
The primary combustibles of concern in the Fire Zone 98-J and 99-M are the in-situ electrical
cabinets, cables, and electrical equipment.
A potential electrical cabinet and subsequent cable tray fire will pose a significant hazard to
these Fire Zones. The most likely scenario is dominated by the cable trays that are closest to
the ignition sources i.e., the electrical cabinet and electrical equipment.
The main ignition sources in the Fire Zone 98-J include, but are not limited to, the electrical
wall-mounted cabinets, 125V DC distribution panels, and instrumentation cabinets (see Table
1). Ignition sources in the Fire Zone 99-M include, but are not limited to, the 4160V switchgear
(vital and non-vital) 480V MCC, 480V load center, 120V instrument panel/transformer Y4/X62,
inverter panels Y28, Y22, Y24, and Y25 (see Table 1).
Table 1
List of Ignition Sources in Fire Zone 98-J and 99-M
ANO Triennial Fire Protection Inspection, Attachment 2, Phase 2 Significance Determination
(ADAMS Accession # ML012530361)
Ignition Sources
Fire Zone 98-J, Emergency Diesel
Generator Corridor
Fire Zone 99-M, North Electrical Switchgear
Room
Electrical wall-mounted cabinets
125V DC distribution panels
Instrumentation cabinets
Emergency chiller water pump
Switchgear room emergency chiller
Battery charger room A/C unit
North batter room/Charger room unit cooler
South battery room/Charger room unit cooler
4160V switchgear (vital and non-vital)
480 V motor control center
480V load center
120V instrument panel/transformer Y4/X62
Inverter panels Y28, Y22, Y24, and Y25
Switchgear room cooler, VUC 2C and 2D
Transformer X6
-2-
Other ignition sources such as a power cable failure in a tray, or other failures of electrical
origin (distribution panel, circuit boards, electrical wiring, internal cable fault, electrical circuit
fault in switchgear cabinets, etc.) will produce similar results. The electrical failure is postulated
in this analysis to ignite the in-situ combustibles (cables). Outside ignition sources such as hot
work or transient sources are also possible, but not included in the scope of this analysis.
FIRE GROWTH RATE
Testing has shown that the overall heat release rate (HRR) during the fire growth phase of
many fires can often be characterized by the simple time dependent polynomial or exponential
function (Heskestad and Delichatsios 1978). The total heat release of fuel packages can be
reasonably approximated by the power law fire growth model for both a single item burning and
for multiple items involved in a fire. The proposed model of the environment generated by fire
in an enclosure is dependent on the assumption that the fire grows according to:
(1)
Q
t
= 2
where
= the rate of heat release of fire (kW),
&Q
t = the time (sec), and
= a constant governing the speed of fire growth (kW/sec2)
The growth rate approximately follows a relationship proportional to time squared for flaming
and radially spreading fires and is referred to as t-squared (t2) fires. The t2 fires are classed by
speed of growth, labeled ultra-fast, fast, medium, and slow. Where these classes are used,
they are defined on the basis of the time required for the fire to grow to a rate of heat release of
1000 kW (1 MW). The intensity , and growth time t, related to each of these classes shown in
Table 2.
Table 2
Summary of t2 Fire Parameter
Type of Fire Growth
Intensity Constant
(kW/sec2)
Growth Time
t (sec)
Slow
0.00293
600
Medium
0.01172
300
Fast
0.0469
150
Ultra-fast
0.1876
75
The t2 relationship has proven to be useful and has been adopted into the National Fire
Protection Association NFPA 72 to categorize fires for detector spacing requirements and into
NFPA 92B for design of smoke control system.
-3-
The modeled fire can be represented as one where the HRR per unit area is constant over the
entire ignited surface and the flame is spreading with a steadily increasing area. In such cases,
the burning area increases as the square of the steadily increasing fire radius. Fires that do not
have a regular fuel array and consistent burning rate might or might not actually produce a t2
curve; however, the t2 approximation appears to be reasonable for use in this case to produce a
realistic approximation of the expected fire growth.
HEAT RELEASE RATE ESTIMATE
This analysis is used to determined the extend of potential fire damage associated with a
realistic, potential fire scenario in Fire Zones 98-J and 99-M. The analysis evaluates whether
the postulated fire can lead to failure of safety-related cables or equipment of redundant trains
of systems for safe shutdown. The impact of the fire scenario is analyzed using fire dynamics
principles or fire model (e.g., CFAST). Different fire scenarios were considered in the analysis.
Table 3 provides a summary of fire scenarios considered in this analysis.
Table 3
Summary of the Fire Scenarios
Fire Zone
Fire Scenario
Ventilation
Condition
Electrical Cabinet Fire
Input HRR, Test # 23 & 24,
NUREG/CR-4527, Volume 2,
Figure 1 & 2
Electrical
Equipment Fire
t2 Fast Fire
Growth
Figure 3
98-J, Emergency
Diesel Generator
Corridor
1300 kW Peak HRR
1235 kW Peak HRR
500 kW
400 kW
300 kW
200 kW
Vent open and
closed
99-M, North
Electrical
Switchgear Room
1300 kW Peak HRR
1235 kW Peak HRR
500 kW
400 kW
300 kW
200 kW
Door open and
closed
Figure 1 and 2 show the input HRR used in CFAST fire simulation predicts the effects of a
electrical cabinet fire in Fire Zone 98-J and Fire Zone 99-M. This HRR is based on the full-
scale test results reported in NUREG/CR-4527, Volume 2, Test # 23 and 24. As shown in
Table 1 several small electrical ignition sources are present in Fire Zones 98-J and 99-M.
There is no direct data available on the burning of these ignition sources at full or intermediate
scale, so a range of HRR were used. For the purpose of this analysis a t2 fast fire growth rate
for these fires was assumed for fire modeling (see Figure 3).
-4-
-5-
-6-
Figure 3 Input Heat Release Rate, Electrical Equipment Fire, t
2 Fast Fire Growth Rate
0
100
200
300
400
500
600
0
20
40
60
80
100
120
Time (sec)
500 kW Fire
400 kW Fire
300 kW Fire
200 kW Fire
-7-
CFAST - CONSOLIDATED MODEL OF FIRE GROWTH AND SMOKE TRANSPORT
The multi-zone computer fire model CFAST was used to calculate the temperature in the Fire
Zones 98-J and 99-M [Peacock et al., 1997; Peacock et al., 1993]. CFAST was developed by
the Building and Fire Research Laboratory (BFRL) at the National Institute of Standards and
Technology (NIST) for fire modeling steady and unsteady state burning rates in multiple
compartment configurations (multiple room capability, up to 15 rooms can be modeled). The
initiating fire is user specified, but adjusted by CFAST based on the available supply of oxygen.
CFAST allows fires to be constrained or unconstrained. A fire specified as unconstrained in
CFAST will not be limited by the availability of oxygen. When a constrained fire is specified, the
chemically required oxygen is calculated and the available oxygen and unburned gases are
tracked. A mass balance calculation of individual species is performed for each zone to track
the available oxygen and unburned gases. Multiple compartments and vents can be modeled
as well as the mechanical ventilation. Mechanical ventilation is addressed by CFAST in terms
of fan/ductwork that includes consideration of fan pressure/flow characteristic curves and duct
friction losses. The model divides each compartment into two zones, an upper zone containing
the hot gases produced by the fire and a lower zone containing all space beneath the upper
zone. The lower zone is a source of air for combustion and usually the location of the fire
source, the upper zone can expand to occupy virtually all of the space in the compartment. The
upper zone is considered a control volume that receives both mass and energy for the fire and
loses energy to the surfaces in contact with the upper zone by conduction and radiation, by
radiation to the floor, and by convection or mass movement of gases through openings. The
two layer zone approach used by the CFAST has evolved from observations of such layering in
full-scale fire experiments (Jones et al., 2000). While these experiments show some variation
in conditions within the layers, they are small compared to the differences in conditions between
the layers themselves. Thus, the zone model can produce a fairly realistic simulation of the fire
environment within a compartment under most conditions. CFAST has the capability to
calculate the upper and lower layer temperature, the smoke density, the vent flow rate, the gas
concentrations, and compartment boundary temperatures, the heat flux from the smoke layer to
objects, the internal compartment pressure, and the interface elevation, all as a function of time.
A number of efforts of CFAST model comparison, verification and validation have been
undertaken. Many of these efforts involved comparisons between measured and calculated
parameters, primarily temperatures, mass flow rates and smoke layer interface positions.
Duong, 1990, Peacock, et al., 1988, Mowrer and Gautier, 1997, Nelson and Deal, 1991, and
EPRI TR-108875, 1998, compared CFAST model predictions with experimental data.
LIMITATIONS AND UNCERTAINTIES ASSOCIATED WITH FIRE MODELING
Fire models permit development of a better understanding of the dynamics of building fires and
can aid in the fire safety decision-making process. There are certain limitations and
uncertainties associated with the current fire modeling predictions. Extreme care must be
exercised in the interpretation of the fire modeling results. For scenarios where the level of
predicted hazard is well below the damage threshold, the results can be used with high level of
confidence provided there is a high level of confidence that all risk-significant scenarios have
been considered. For scenarios where the level of predicted hazard is near the damage
threshold, the results should be used with caution in view of the uncertainties that exist.
-8-
A primary method of handling modeling uncertainties is the use of engineering judgment.
Among other things, this judgment is reflected in the selection of appropriate fire scenario,
hazard criteria, and fire modeling techniques. A slightly more formal application of engineering
judgment is the use of safety factors. The safety factors can be applied in the form of fire size,
increased or decreased fire growth rate, or conservative hazard criteria (Custer and Meacham,
1997). Experimental data obtained from fire test, statistical data, from actual fire experience,
and other expert judgment can be used improve the judgment and potentially decrease the
level of uncertainty.
CFAST MODELING OF FIRE ZONES 98-J AND 99-M
Fire modeling of the Fire Zones 98-J and 99-M was performed using CFAST. All CFAST input
files used in this analysis are contained in Appendix A. With the parameters selected, CFAST
provided information on the temperature in the room and the smoke interface height.
CFAST input data includes the physical dimensions of the compartment, the compartment
construction materials, the opening dimensions and their elevations, the fire HRR, and the
position of the fire in the specified room, gas species production rate, and exterior wind
conditions (see input file).
To perform this analysis, several HRR curves were developed for the CFAST fire model. The
input HRR assumes complete combustion and an ample supply of oxygen. Experimental HRR
curves (NUREG/CR-4527, Vol. 2) and electrical equipment fire with a t2 fast fire growth rate
(i.e., energized failure) was used in the fire modeling.
The fire environment created in the Fire Zones 98-J and 99-M involving electrical cabinet and
electrical equipment was determined using the data provided in Table 3. HRR data in Figures
1, 2, and 3, and Table 3 were used as input into CFAST, which will reduce this nominal HRR
based on the availability of oxygen. In Fire Zone 99-J, fires were evaluated first with the vent
open (3 x 2) then closed. In Fire Zone 99-M fires were evaluated first with the door open then
closed. In the cases of the vent or door closed, a small vent was assumed near the floor to
prevent an excessive pressure buildup and possible numerical instability in the model. This
small vent assumption is reasonable and realistic since no compartment is air tight. For the
model a summation of small leakage paths such as door gaps are assumed. The walls, floor,
and ceiling of Fire Zones 98-J and Fire Zone 99-M are thermally thick concrete.
CFAST FIRE MODELING RESULTS
Results from the CFAST simulation of the fire scenarios in the Fire Zone 98-J and 99-M are
provided in Figures 4 through 19 and summarized in Table 4. Figure 4 show the smoke layer
temperature in Fire Zone 98-J using the input HRR from Test # 23 with vent open and closed.
In this figure cable failure temperature 425 °F was reached in approximately 30 minutes when
vent is open. In the case of vent closed the fire become ventilation limited with the smoke layer
temperature reaching 400 °F in about 30 minutes. Figure 6 show the smoke layer temperature
in Fire Zone 99-M using input HRR from Test # 23 with door open and closed. In both case the
smoke layer temperature reach 425 °F approximately 11.5 minutes. The limiting temperature of
425 °F was used since this temperature can, cause failure of non IEEE-383 rated cables.
-9-
Figure 8 show the smoke layer temperature in Fire Zone 98-J using input HRR from Test # 24
with vent open and closed. In both fire scenarios, the smoke layer temperature reach in 425 °F
approximately 6 minutes. In Figure 10 the smoke hot layer temperature in Fire Zone 99-M to
reach 425 °F within 7 minute of the fire.
Figure 12 and 14 show the smoke layer temperature in Fire Zone 98-J with door open and then
closed with HRR ranging from 200 to 500 kW. The temperatures reached during these fire
scenarios exceeds 425 °F only for 300 and 400 kW fire when vent is open. In case when vent
is closed, smoke layer temperature exceeds 425 °F only for 500 kW fire, other fires become
ventilation limited and decayed.
Figure 16 and 18 show the smoke layer temperature in Fire Zone 99-M with door open and
closed with HRR ranging from 200 to 500 kW. With the door open, in all cases the smoke layer
temperature was below the non IEEE-383 rated failure temperature, therefore failure of the
cables would not be expected. However, with the door closed, fires with HRR of 400 and
greater could damage the cables in Fire Zone 99-M. Fires with HRR of 200 and 300 kW tend
to become ventilation limited and decayed.
Table 4
Summary of Fire Modeling Results for Electrical Cabinet and Electrical Equipment Fire in Fire
Zone 98-J and 99-M
Fire Scenario
HRR (kW)
Fire Zone 98-J, Emergency Diesel
Generator Corridor
Fire Zone 99-M, North Electric
Switchgear Room
Smoke Layer Temperature
(°F)
Smoke Layer Temperature
(°F)
Vent Open
Vent Closed
Door Open
Door Closed
1300
425 @ 6 min
425 @ 6 min
425 @ 7 min
425 @ 7 min
1235
400 @ 9 min
425 @ 30 min
400 @ min
425 @ 11.5 min
425 @ 11.5
min
500
425 @ 4 min
425 @ 3.5 min
363 @ 60 min
425 @ 5 min
400
425 @ 19 min
408 @ 6 min
325 @ 60 min
425 @ 10 min
300
390 @ 60 min
336 @ 14 min
284 @ 60 min
369 @ 27 min
200
305 @ 60 min
291 @ 19 min
230 @ 60 min
294 @ 27 min
Boldface indicate the non IEEE-383 rated cable failure temperature.
CONCLUSION
As expected and illustrated by Table 4, the damaging fire scenarios will be governed by the
energetic faults in the electrical cabinets (HRR) and influenced by the compartment's ventilation
conditions. Energetic electrical faults producing a HRR 400 kW or greater, can lead to fire
growth and subsequent fire damage of concern in the compartment. Based on operating
-10-
experience (e.g., the recent event at San Onofre Nuclear Generating Station (SONGS)(ADAMS
Accession # ML011130255)) and laboratory testing (e.g., An Experimental Investigation of
Internally Ignited Fires in Nuclear Power Plant Control Cabinets, Part II: Room Effects Tests
NUREG/CR-4527, Volume 2) fires in excess of 1 MW (1000 kW) are creditable from electrical
cabinets. This HRR is further validated by the February 2002, NRC Office of Nuclear
Regulatory Research Report Operating Experience Assessment Energetic Faults in 4.16 kV to
13.8 kV Switchgear and Bus Ducts That Caused Fires in Nuclear Power Plants 1986-2001
(ADAMS Package # ML021290364, Report Accession # ML021290358), which states,
These events demonstrate that fires from energetic electrical faults contain more
energy than assumed in fire risk models as evidenced by explosions, arcing, smoke,
ionized gases, and melting and vaporizing of equipment. The energy release exceeds
HRRs assumed in fire risk models, possibly by a factor of 1000. Lower HHR values
currently used may explain why current fire risk models have not identified the potential
larger effects of fires from energetic electrical faults which may include the following:
bypass of the fire initiation and growth stages, propagation of the fire to other equipment
and across vertical fire barriers, ac power system designs that may be vulnerable to an
SBO, failed fire suppression attempts with dry chemicals and the need to use water,
longer restoration time to recover, and unexpected challenges and distractions to the
operator from fire-induced failures.
Fire risk models may underestimate the risks from fires due to energetic faults in 4.16
kV to 13.8 kV switchgear and bus ducts by not considering: (1) development of HRR
values corresponding to energetic electrical energy levels; (2) the effects of propagation
from the fault location to other switchgear compartments, bus ducts, or overhead
cables; (3) plant ac safety bus and circuit breaker configuration; (4) failed fire
suppression attempts; (5) additional recovery actions; and (6) multiple accident
sequences from fire induced equipment failures or operator error.
Therefore, based on the realistic fire scenarios developed in this analysis, unacceptable fire
damage due to an energized electrical cabinet ignited fire is credible.
-11-
Figure 4 Smoke Layer Temperature in Fire Zone 98-J. Input Heat Release Rate Test # 23,
NUREG/CR-4527, Volume 2
0
100
200
300
400
500
600
700
0
500
1000
1500
2000
2500
3000
3500
Time (sec)
Vent Closed
Vent Open
IEEE-383 Non-Rated Cable Failure Temperature = 425 °F
-12-
Figure 5 Smoke Layer Height in Fire Zone 98-J. Input Heat Release Rate Test # 23,
NUREG/CR-4527, Volume 2
0
2
4
6
8
10
12
14
0
500
1000
1500
2000
2500
3000
3500
Time (sec)
Vent Open
Vent Closed
-13-
Figure 6 Smoke Layer Temperature in Fire Zone 99-M. Input Heat Release Rate Test # 23,
NUREG/CR-4527, Volume 2
0
100
200
300
400
500
600
0
500
1000
1500
2000
2500
3000
3500
Time (sec)
Door Closed
Door Open
IEEE-383 Non-Rated Cable Failure Temperature = 425 °F
-14-
Figure 7 Smoke Layer Height in Fire Zone 99-M. Input Heat Release Rate Test # 23,
NUREG/CR-4527, Volume 2
0
2
4
6
8
10
12
14
0
500
1000
1500
2000
2500
3000
3500
Time (sec)
Door Open
Door Closed
-15-
Figure 8 Smoke Layer Temperature in Fire Zone 98-J. Input Heat Release Rate Test # 24,
NUREG/CR-4527, Volume 2
0
50
100
150
200
250
300
350
400
450
500
0
500
1000
1500
2000
2500
3000
3500
Time (sec)
Vent Closed
Vent Open
IEEE-383 Non-Rated Cable Failure Temperature = 425 °F
-16-
Figure 9 Smoke Layer Height in Fire Zone 98-J. Input Heat Release Rate Test # 24,
NUREG/CR-4527, Volume 2
0
2
4
6
8
10
12
14
0
500
1000
1500
2000
2500
3000
3500
Time (sec)
Vent Open
Vent Closed
-17-
Figure 10 Smoke Layer Temperature in Fire Zone 99-M. Input Heat Release Rate Test # 24,
NUREG/CR-4527, Volume 2
0
100
200
300
400
500
600
0
500
1000
1500
2000
2500
3000
3500
Time (sec)
Door Closed
Door Open
IEEE-383 Non-Rated Cable Failure Temperature = 425 °F
-18-
Figure 11 Smoke Layer Height in Fire Zone 99-M. Input Heat Release Rate Test # 24,
NUREG/CR-4527, Volume 2
0
2
4
6
8
10
12
14
0
500
1000
1500
2000
2500
3000
3500
Time (sec)
Door Open
Door Closed
-19-
Figure 12 Smoke Layer Temperature in Fire Zone 98-J, Emergency Diesel Generator Corridor, Vent Open
0
100
200
300
400
500
600
0
500
1000
1500
2000
2500
3000
3500
Time (sec)
200 kW Fire
300 kW Fire
400 kW Fire
500 kW Fire
IEEE-383 Non-Rated Cable Failure Temperature = 425 °F
-20-
Figure 13 Smoke Layer Height in Fire Zone 98-J, Emergency Diesel Generator Corridor, Vent Open
0
2
4
6
8
10
12
14
0
500
1000
1500
2000
2500
3000
3500
Time (sec)
-21-
Figure 14 Smoke Layer Temperature in Fire Zone 98-J, Emergency Diesel Generator Corridor,
Vent Closed
0
50
100
150
200
250
300
350
400
450
500
0
500
1000
1500
2000
2500
3000
3500
Time (sec)
200 kW Fire
300 kW Fire
400 kW
500 kW Fire
IEEE-383 Non-Rated Cable Failure Temperature = 425 °F
-22-
Figure 15 Smoke Layer Height in Fire Zone 98-J, Emergency Diesel Generator Corridor, Vent Closed
0
2
4
6
8
10
12
14
0
500
1000
1500
2000
2500
3000
3500
Time (sec)
-23-
Figure 16 Smoke Layer Temperature in Fire Zone 99-M, North Electrical Switchgear Room, Door Open
0
50
100
150
200
250
300
350
400
450
0
500
1000
1500
2000
2500
3000
3500
Time (sec)
200 kW Fire
300 kW Fire
400 kW Fire
500 kW Fire
IEEE-383 Non-Rated Cable Failure Temperature = 425 °F
-24-
Figure 17 Smoke Layer Height in Fire Zone 99-M, North Electrical Switchgear Room, Door Open
0
2
4
6
8
10
12
14
0
500
1000
1500
2000
2500
3000
3500
Time (sec)
-25-
Figure 18 Smoke Layer Temperature in Fire Zone 99-M, North Electrical Switchgear Room, Door Closed
0
50
100
150
200
250
300
350
400
450
500
0
500
1000
1500
2000
2500
3000
3500
Time (sec)
200 kW Fire
300 kW Fire
400 kW Fire
500 kW
IEEE-383 Non-Rated Cable Failure Temperature = 425 °F
-26-
Figure 19 Smoke Layer Height in Fire Zone 99-M, North Electrical Switchgear Room, Door Closed
0
2
4
6
8
10
12
14
0
500
1000
1500
2000
2500
3000
3500
Time (sec)
-27-
REFERENCES
Babrauskas, V., Burning Rates, Section 3, Chapter 3-1, SFPE Handbook of Fire Protection
Engineering, 2nd Edition, DiNenno, P. J., Editor-in-Chief, National Fire Protection Association,
Quincy, Massachusetts, 1995.
Custer, R. L., and Meacham, B. J., Uncertainty and Safety Factors, Chapter 9, Introduction to
Performance-Based Fire Safety, Society of Fire Protection Engineers (SFPE) and National Fire
Protection Association (NFPA), Quincy, Massachusetts, 1997.
Duong, D. Q., Accuracy of Computer Fire Models: Some Comparisons With Experimental Data
From Australia, Fire Safety Journal, Volume 16, No. 6, 1990, pp. 415-431.
Heskestad,. G., and Delichatsios, M. A., The Initial Convective Flow in Fire, Seventeenth
Symposium (International) on Combustion, The Combustion Institute, Pittsburgh, Pennsylvania,
1978, pp.1113-1123.
EPRI, TR-108875, Fire Modeling Code Comparisons, Electric Power Research Institute, Palo
Alto, California, 1998.
Jones, W. W., Forney, G. P., Peacock, R. D., and Reneke, P. A., A Technical Reference for
CFAST: An Engineering Tool for Estimating Fire and Smoke Transport, NIST TN 1431, U.S.
Department of Commerce, National Institute of Standards and Technology (NIST), Building and
Fire Research Laboratory (BFRL), Gaithersburg, Maryland, January 2000.
Mowrer, F. W., and Gauiter, B., Comparison of Fire Model Features and Computations, 17th
Structural Mechanics in Reactor Technology (SMiRT), Post-Conference Fire Protection
Seminar, Lyons, France, 1997.
Nelson, H. E., and Deal, S., "Comparing Compartment Fires with Compartment Fire Models,"
Fire Safety Science-Proceedings of the Third International Symposium, International
Association of Fire Safety Science (IAFSS), Scotland, UK., Cox and Langford, Editors, Elsevier
Applied Science London and New York, July 8-12, 1991, pp. 719-728.
NFPA 72, National Fire Alarm Code, National Fire Protection Association, Quincy,
Massachusetts, 1999 Edition.
NFPA 92B, Guide for Smoke Management Systems in Malls, Atria, and Large Areas, National
Fire Protection Association, Quincy, Massachusetts, 2000 Edition.
NRC Inspection Report No. 50-362/01-05, San Onofre Nuclear Generating Station NRC
Special Team Inspection Report, April 20, 200 (ADAMS Accession # ML011130255).
NUREG/CR-4527, Volume 2, An Experimental Investigation of Internally Ignited Fires in
Nuclear Power Plant Control Cabinets, Part II: Room Effects Tests U.S. Nuclear Regulatory
Commission, Washington, DC, November 1988.
-28-
Peacock, R. D., Davis, S., and Lee, B. T., "An Experimental Data Set for the Accuracy
Assessment of Room Fire Model, NBSIR 88-3752, National Bureau of Standards,
Gaithersburg, Maryland, 1988.
Peacock, R. D., Forney, G.P., Reneke, P. A., Portier, R., and Jones, W. W.,"CFAST, the
Consolidated Model of Fire Growth and Smoke Transport," NIST Technical Note 1299, U.S.
Department of Commerce, Building and Fire Research Laboratory (BFRL), National Institute of
Standards and Technology (NIST), Gaithersburg, Maryland, February 1993.
Peacock, R. D., Reneke, P. A., Jones, W. W., Bukowski, R. W., and Forney, G. P.,
"A Users Guide for FAST: Engineering Tools for Estimating Fire Growth and Smoke
Transport, Special Publication 921, U.S. Department of Commerce, Building and Fire
Research Laboratory (BFRL), National Institute of Standards and Technology (NIST),
Gaithersburg, Maryland, October 1997.
Task Interface Agreement (TIA), Request for Risk Determination of Fire Protection Finding at
Arkansas Nuclear One, Unit 1 (01TIA11), Memorandum to Ledyard B. Marsh, NRR, from
Arthur T. Howell, Division of Reactor Safety, Region IV, September 10, 2001 (ADAMS
Accession # ML012530361).
-29-
APPENDIX - A
Computational Fire Modeling CFAST Input Data
Fire Zone 98-J, Emergency Diesel Generator Corridor and
99-M, North Electrical Switchgear Room
Arkansas Nuclear One - Unit 1
-30-
VERSN 3 Fire Zone 98-J, 200 kW fire, Vent Open
TIMES 3600 60 60 60 0
TAMB 298. 101300. 0.0
EAMB 298. 101300. 0.0
HI/F 0.0
WIDTH 2.76
DEPTH 18.28
HEIGH 3.65
HVENT 1 2 1 0.9144 0.6096 0.0 0.0
CEILI CONCRETE
WALLS CONCRETE
FLOOR CONCRETE
CHEMI 16. 10. 10 24000000. 298. 388. 0.2
LFBO 1
LFBT 2
FPOS -1.0 -1.0 0.0
FTIME 30.0 60.0 66.0
FHIGH 0.5 0.5 0.5
FAREA 0.5 0.5 0.5
FQDOT 0.0 42210 168840 200000
CJET OFF
CO 0.14 0.14 0.14
OD 0.05 0.05 0.05
HCR 0.30 0.30 0.30
STPMAX 1.00
DUMPR ANO-1.Hi
DEVICE 1
WINDOW 0 0. -100. 1280. 1024. 1100.
GRAPH 1 170. 300. 0. 625. 820. 10. 5 TIME CELSIUS
GRAPH 2 765. 300. 0. 1220. 820. 10. 5 TIME FIRE_SIZE (kW)
LABEL 1 970. 960. 0. 1231. 1005. 10. 15 00:00:00 0. 0.
LABEL 2 690. 960. 0. 987. 1005. 10. 13 TIME_ [SEC] 0. 0.
TEMPERA 0 0 0 0 1 1 U
HEAT 0 0 0 0 2 1 U
-31-
VERSN 3 Fire Zone 98-J, 300 kW fire, Vent Open
TIMES 3600 60 60 60 0
TAMB 298. 101300. 0.0
EAMB 298. 101300. 0.0
HI/F 0.0
WIDTH 2.76
DEPTH 18.28
HEIGH 3.65
HVENT 1 2 1 0.9144 0.6096 0.0 0.0
CEILI CONCRETE
WALLS CONCRETE
FLOOR CONCRETE
CHEMI 16. 10. 10 24000000. 298. 388. 0.2
LFBO 1
LFBT 2
FPOS -1.0 -1.0 0.0
FTIME 30.0 60.0 80.0
FHIGH 0.5 0.5 0.5
FAREA 0.5 0.5 0.5
FQDOT 0.0 42210 168840 300000
CJET OFF
CO 0.14 0.14 0.14
OD 0.05 0.05 0.05
HCR 0.30 0.30 0.03
STPMAX 1.00
DUMPR ANO-2.Hi
DEVICE 1
WINDOW 0 0. -100. 1280. 1024. 1100.
GRAPH 1 170. 300. 0. 625. 820. 10. 5 TIME CELSIUS
GRAPH 2 765. 300. 0. 1220. 820. 10. 5 TIME FIRE_SIZE (kW)
LABEL 1 970. 960. 0. 1231. 1005. 10. 15 00:00:00 0. 0.
LABEL 2 690. 960. 0. 987. 1005. 10. 13 TIME_ [SEC] 0. 0.
TEMPERA 0 0 0 0 1 1 U
HEAT 0 0 0 0 2 1 U
-32-
VERSN 3 Fire Zone 98-J, 400 kW fire, Vent Open
TIMES 3600 60 60 60 0
TAMB 298. 101300. 0.0
EAMB 298. 101300. 0.0
HI/F 0.0
WIDTH 2.76
DEPTH 18.28
HEIGH 3.65
HVENT 1 2 1 0.9144 0.6096 0.0 0.0
CEILI CONCRETE
WALLS CONCRETE
FLOOR CONCRETE
CHEMI 16. 10. 10 24000000. 298. 388. 0.2
LFBO 1
LFBT 2
FPOS -1.0 -1.0 0.0
FTIME 30. 60.0 93.0
FHIGH 0.5 0.5 0.5
FAREA 0.5 0.5 0.5
FQDOT 0.0 42210 168840 400000
CJET OFF
CO 0.14 0.14 0.14
OD 0.05 0.05 0.05
HCR 0.30 0.30 0.30
STPMAX 1.00
DUMPR ANO-3.Hi
DEVICE 1
WINDOW 0 0. -100. 1280. 1024. 1100.
GRAPH 1 170. 300. 0. 625. 820. 10. 5 TIME CELSIUS
GRAPH 2 765. 300. 0. 1220. 820. 10. 5 TIME FIRE_SIZE (kW)
LABEL 1 970. 960. 0. 1231. 1005. 10. 15 00:00:00 0. 0.
LABEL 2 690. 960. 0. 987. 1005. 10. 13 TIME_ [SEC] 0. 0.
TEMPERA 0 0 0 0 1 1 U
HEAT 0 0 0 0 2 1 U
-33-
VERSN 3 Fire Zone 98-J, 500 kW fire, Vent Open
TIMES 3600 60 60 60 0
TAMB 298. 101300. 0.0
EAMB 298. 101300. 0.0
HI/F 0.0
WIDTH 2.76
DEPTH 18.28
HEIGH 3.65
HVENT 1 2 1 0.9144 0.6096 0.0 0.0
CEILI CONCRETE
WALLS CONCRETE
FLOOR CONCRETE
CHEMI 16. 10. 10 24000000. 298. 388. 0.2
LFBO 1
LFBT 2
FPOS -1.0 -1.0 0.0
FTIME 30.0 60.0 104.0
FHIGH 0.5 0.5 0.5
FAREA 0.5 0.5 0.5
FQDOT 0.0 42210 168840 500000
CJET OFF
CO 0.14 0.14 0.14
OD 0.05 0.05 0.05
HCR 0.30 0.30 0.30
STPMAX 1.00
DUMPR ANO-4.Hi
DEVICE 1
WINDOW 0 0. -100. 1280. 1024. 1100.
GRAPH 1 170. 300. 0. 625. 820. 10. 5 TIME CELSIUS
GRAPH 2 765. 300. 0. 1220. 820. 10. 5 TIME FIRE_SIZE (kW)
LABEL 1 970. 960. 0. 1231. 1005. 10. 15 00:00:00 0. 0.
LABEL 2 690. 960. 0. 987. 1005. 10. 13 TIME_ [SEC] 0. 0.
TEMPERA 0 0 0 0 1 1 U
HEAT 0 0 0 0 2 1 U
-34-
VERSN 3 Fire Zone 98-J, 200 kW fire, Vent Closed
TIMES 3600 60 60 60 0
TAMB 298. 101300. 0.0
EAMB 298. 101300. 0.0
HI/F 0.0
WIDTH 2.76
DEPTH 18.28
HEIGH 3.65
HVENT 1 2 1 0.6096 0.3048 0.0 0.0
CEILI CONCRETE
WALLS CONCRETE
FLOOR CONCRETE
CHEMI 16. 10. 10 24000000. 298. 388. 0.2
LFBO 1
LFBT 2
FPOS -1.0 -1.0 0.0
FTIME 30.0 60.0 66.0
FHIGH 0.5 0.5 0.5
FAREA 0.5 0.5 0.5
FQDOT 0.0 42210 168840 200000
CJET OFF
CO 0.14 0.14 0.14
OD 0.05 0.05 0.05
HCR 0.30 0.30 0.30
STPMAX 1.00
DUMPR ANO-5.Hi
DEVICE 1
WINDOW 0 0. -100. 1280. 1024. 1100.
GRAPH 1 170. 300. 0. 625. 820. 10. 5 TIME CELSIUS
GRAPH 2 765. 300. 0. 1220. 820. 10. 5 TIME FIRE_SIZE (kW)
LABEL 1 970. 960. 0. 1231. 1005. 10. 15 00:00:00 0. 0.
LABEL 2 690. 960. 0. 987. 1005. 10. 13 TIME_ [SEC] 0. 0.
TEMPERA 0 0 0 0 1 1 U
HEAT 0 0 0 0 2 1 U
-35-
VERSN 3 Fire Zone 98-J, 300 kW fire, Vent Closed
TIMES 3600 60 60 60 0
TAMB 298. 101300. 0.0
EAMB 298. 101300. 0.0
HI/F 0.0
WIDTH 2.76
DEPTH 18.28
HEIGH 3.65
HVENT 1 2 1 0.6096 0.3048 0.0 0.0
CEILI CONCRETE
WALLS CONCRETE
FLOOR CONCRETE
CHEMI 16. 10. 10 24000000. 298. 388. 0.2
LFBO 1
LFBT 2
FPOS -1.0 -1.0 0.0
FTIME 30.0 60.0 80.0
FHIGH 0.5 0.5 0.5
FAREA 0.5 0.5 0.5
FQDOT 0.0 42210 168840 300000
CJET OFF
CO 0.14 0.14 0.14
OD 0.05 0.05 0.05
HCR 0.30 0.30 0.03
STPMAX 1.00
DUMPR ANO-6.Hi
DEVICE 1
WINDOW 0 0. -100. 1280. 1024. 1100.
GRAPH 1 170. 300. 0. 625. 820. 10. 5 TIME CELSIUS
GRAPH 2 765. 300. 0. 1220. 820. 10. 5 TIME FIRE_SIZE (kW)
LABEL 1 970. 960. 0. 1231. 1005. 10. 15 00:00:00 0. 0.
LABEL 2 690. 960. 0. 987. 1005. 10. 13 TIME_ [SEC] 0. 0.
TEMPERA 0 0 0 0 1 1 U
HEAT 0 0 0 0 2 1 U
-36-
VERSN 3 Fire Zone 98-J, 400 kW fire, Vent Closed
TIMES 3600 60 60 60 0
TAMB 298. 101300. 0.0
EAMB 298. 101300. 0.0
HI/F 0.0
WIDTH 2.76
DEPTH 18.28
HEIGH 3.65
HVENT 1 2 1 0.6096 0.3048 0.0 0.0
CEILI CONCRETE
WALLS CONCRETE
FLOOR CONCRETE
CHEMI 16. 10. 10 24000000. 298. 388. 0.2
LFBO 1
LFBT 2
FPOS -1.0 -1.0 0.0
FTIME 30. 60.0 93.0
FHIGH 0.5 0.5 0.5
FAREA 0.5 0.5 0.5
FQDOT 0.0 42210 168840 400000
CJET OFF
CO 0.14 0.14 0.14
OD 0.05 0.05 0.05
HCR 0.30 0.30 0.30
STPMAX 1.00
DUMPR ANO-7.Hi
DEVICE 1
WINDOW 0 0. -100. 1280. 1024. 1100.
GRAPH 1 170. 300. 0. 625. 820. 10. 5 TIME CELSIUS
GRAPH 2 765. 300. 0. 1220. 820. 10. 5 TIME FIRE_SIZE (kW)
LABEL 1 970. 960. 0. 1231. 1005. 10. 15 00:00:00 0. 0.
LABEL 2 690. 960. 0. 987. 1005. 10. 13 TIME_ [SEC] 0. 0.
TEMPERA 0 0 0 0 1 1 U
HEAT 0 0 0 0 2 1 U
-37-
VERSN 3 Fire Zone 98-J, 500 kW fire, Vent Closed
TIMES 3600 60 60 60 0
TAMB 298. 101300. 0.0
EAMB 298. 101300. 0.0
HI/F 0.0
WIDTH 2.76
DEPTH 18.28
HEIGH 3.65
HVENT 1 2 1 0.6096 0.3048 0.0 0.0
CEILI CONCRETE
WALLS CONCRETE
FLOOR CONCRETE
CHEMI 16. 10. 10 24000000. 298. 388. 0.2
LFBO 1
LFBT 2
FPOS -1.0 -1.0 0.0
FTIME 30.0 60.0 104.0
FHIGH 0.5 0.5 0.5
FAREA 0.5 0.5 0.5
FQDOT 0.0 42210 168840 500000
CJET OFF
CO 0.14 0.14 0.14
OD 0.05 0.05 0.05
HCR 0.30 0.30 0.30
STPMAX 1.00
DUMPR ANO-8.Hi
DEVICE 1
WINDOW 0 0. -100. 1280. 1024. 1100.
GRAPH 1 170. 300. 0. 625. 820. 10. 5 TIME CELSIUS
GRAPH 2 765. 300. 0. 1220. 820. 10. 5 TIME FIRE_SIZE (kW)
LABEL 1 970. 960. 0. 1231. 1005. 10. 15 00:00:00 0. 0.
LABEL 2 690. 960. 0. 987. 1005. 10. 13 TIME_ [SEC] 0. 0.
TEMPERA 0 0 0 0 1 1 U
HEAT 0 0 0 0 2 1 U
-38-
VERSN 3 Fire Zone 99-M, 200 kW fire, Door Open
TIMES 3600 60 60 60 0
TAMB 298. 101300. 0.0
EAMB 298. 101300. 0.0
HI/F 0.0
WIDTH 10.56
DEPTH 7.72
HEIGH 3.65
HVENT 1 2 1 1.82 2.44 0.0 0.0
CEILI CONCRETE
WALLS CONCRETE
FLOOR CONCRETE
CHEMI 16. 10. 12. 24000000. 298. 388. 0.2
LFBO 1
LFBT 2
FPOS -1.0 -1.0 0.0
FTIME 30.0 60.0 66.0
FHIGH 0.5 0.5 0.5
FAREA 0.5 0.5 0.5
FQDOT 0.0 42210 168840 200000
CJET OFF
CO 0.14 0.14 0.14
OD 0.05 0.05 0.05
HCR 0.30 0.30 0.30
STPMAX 1.00
DUMPR ANO-9.Hi
DEVICE 1
WINDOW 0 0. -100. 1280. 1024. 1100.
GRAPH 1 170. 300. 0. 625. 820. 10. 5 TIME CELSIUS
GRAPH 2 765. 300. 0. 1220. 820. 10. 5 TIME FIRE_SIZE (kW)
LABEL 1 970. 960. 0. 1231. 1005. 10. 15 00:00:00 0. 0.
LABEL 2 690. 960. 0. 987. 1005. 10. 13 TIME_ [SEC] 0. 0.
TEMPERA 0 0 0 0 1 1 U
HEAT 0 0 0 0 2 1 U
-39-
VERSN 3 Fire Zone 99-M, 300 kW fire, Door Open
TIMES 3600 60 60 60 0
TAMB 298. 101300. 0.0
EAMB 298. 101300. 0.0
HI/F 0.0
WIDTH 10.56
DEPTH 7.72
HEIGH 3.65
HVENT 1 2 1 1.82 2.44 0.0 0.0
CEILI CONCRETE
WALLS CONCRETE
FLOOR CONCRETE
CHEMI 16. 10. 12. 24000000. 298. 388. 0.2
LFBO 1
LFBT 2
FPOS -1.0 -1.0 0.0
FTIME 30.0 60.0 80.0
FHIGH 0.5 0.5 0.5
FAREA 0.5 0.5 0.5
FQDOT 0.0 42210 168840 300000
CJET OFF
CO 0.14 0.14 0.14
OD 0.05 0.05 0.05
HCR 0.30 0.30 0.30
STPMAX 1.00
DUMPR ANO-10.Hi
DEVICE 1
WINDOW 0 0. -100. 1280. 1024. 1100.
GRAPH 1 170. 300. 0. 625. 820. 10. 5 TIME CELSIUS
GRAPH 2 765. 300. 0. 1220. 820. 10. 5 TIME FIRE_SIZE (kW)
LABEL 1 970. 960. 0. 1231. 1005. 10. 15 00:00:00 0. 0.
LABEL 2 690. 960. 0. 987. 1005. 10. 13 TIME_ [SEC] 0. 0.
TEMPERA 0 0 0 0 1 1 U
HEAT 0 0 0 0 2 1 U
-40-
VERSN 3 Fire Zone 99-M, 400 kW fire, Door Open
TIMES 3600 60 60 60 0
TAMB 298. 101300. 0.0
EAMB 298. 101300. 0.0
HI/F 0.0
WIDTH 10.56
DEPTH 7.72
HEIGH 3.65
HVENT 1 2 1 1.82 2.44 0.0 0.0
CEILI CONCRETE
WALLS CONCRETE
FLOOR CONCRETE
CHEMI 16. 10. 12. 24000000. 298. 388. 0.2
LFBO 1
LFBT 2
FPOS -1.0 -1.0 0.0
FTIME 30.0 60.0 93.0
FHIGH 0.5 0.5 0.5
FAREA 0.5 0.5 0.5
FQDOT 0.0 42210 168840 400000
CJET OFF
CO 0.14 0.14 0.14
OD 0.05 0.05 0.05
HCR 0.30 0.30 0.30
STPMAX 1.00
DUMPR ANO-11.Hi
DEVICE 1
WINDOW 0 0. -100. 1280. 1024. 1100.
GRAPH 1 170. 300. 0. 625. 820. 10. 5 TIME CELSIUS
GRAPH 2 765. 300. 0. 1220. 820. 10. 5 TIME FIRE_SIZE (kW)
LABEL 1 970. 960. 0. 1231. 1005. 10. 15 00:00:00 0. 0.
LABEL 2 690. 960. 0. 987. 1005. 10. 13 TIME_ [SEC] 0. 0.
TEMPERA 0 0 0 0 1 1 U
HEAT 0 0 0 0 2 1 U
-41-
VERSN 3 Fire Zone 99-M, 500 kW fire, Door Open
TIMES 3600 60 60 60 0
TAMB 298. 101300. 0.0
EAMB 298. 101300. 0.0
HI/F 0.0
WIDTH 10.56
DEPTH 7.72
HEIGH 3.65
HVENT 1 2 1 1.82 2.44 0.0 0.0
CEILI CONCRETE
WALLS CONCRETE
FLOOR CONCRETE
CHEMI 16. 10. 12. 24000000. 298. 388. 0.2
LFBO 1
LFBT 2
FPOS -1.0 -1.0 0.0
FTIME 30.0 60.0 104.0
FHIGH 0.5 0.5 0.5
FAREA 0.5 0.5 0.5
FQDOT 0.0 42210 168840 500000
CJET OFF
CO 0.14 0.14 0.14
OD 0.05 0.05 0.05
HCR 0.30 0.30 0.30
STPMAX 1.00
DUMPR ANO-12.Hi
DEVICE 1
WINDOW 0 0. -100. 1280. 1024. 1100.
GRAPH 1 170. 300. 0. 625. 820. 10. 5 TIME CELSIUS
GRAPH 2 765. 300. 0. 1220. 820. 10. 5 TIME FIRE_SIZE (kW)
LABEL 1 970. 960. 0. 1231. 1005. 10. 15 00:00:00 0. 0.
LABEL 2 690. 960. 0. 987. 1005. 10. 13 TIME_ [SEC] 0. 0.
TEMPERA 0 0 0 0 1 1 U
HEAT 0 0 0 0 2 1 U
-42-
VERSN 3 Fire Zone 99-M, 200 kW fire, Door Closed
TIMES 3600 60 60 60 0
TAMB 298. 101300. 0.0
EAMB 298. 101300. 0.0
HI/F 0.0
WIDTH 10.56
DEPTH 7.72
HEIGH 3.65
HVENT 1 2 1 1.0 0.15 0.0 0.0
CEILI CONCRETE
WALLS CONCRETE
FLOOR CONCRETE
CHEMI 16. 10. 12. 24000000. 298. 388. 0.2
LFBO 1
LFBT 2
FPOS -1.0 -1.0 0.0
FTIME 30.0 60.0 66.0
FHIGH 0.5 0.5 0.5
FAREA 0.5 0.5 0.5
FQDOT 0.0 42210 168840 200000
CJET OFF
CO 0.14 0.14 0.14
OD 0.05 0.05 0.05
HCR 0.30 0.30 0.30
STPMAX 1.00
DUMPR ANO-13.Hi
DEVICE 1
WINDOW 0 0. -100. 1280. 1024. 1100.
GRAPH 1 170. 300. 0. 625. 820. 10. 5 TIME CELSIUS
GRAPH 2 765. 300. 0. 1220. 820. 10. 5 TIME FIRE_SIZE (kW)
LABEL 1 970. 960. 0. 1231. 1005. 10. 15 00:00:00 0. 0.
LABEL 2 690. 960. 0. 987. 1005. 10. 13 TIME_ [SEC] 0. 0.
TEMPERA 0 0 0 0 1 1 U
HEAT 0 0 0 0 2 1 U
-43-
VERSN 3 Fire Zone 99-M, 300 kW fire, Door Closed
TIMES 3600 60 60 60 0
TAMB 298. 101300. 0.0
EAMB 298. 101300. 0.0
HI/F 0.0
WIDTH 10.56
DEPTH 7.72
HEIGH 3.65
HVENT 1 2 1 1.0 0.15 0.0 0.0
CEILI CONCRETE
WALLS CONCRETE
FLOOR CONCRETE
CHEMI 16. 10. 12. 24000000. 298. 388. 0.2
LFBO 1
LFBT 2
FPOS -1.0 -1.0 0.0
FTIME 30.0 60.0 80.0
FHIGH 0.5 0.5 0.5
FAREA 0.5 0.5 0.5
FQDOT 0.0 42210 168840 300000
CJET OFF
CO 0.14 0.14 0.14
OD 0.05 0.05 0.05
HCR 0.30 0.30 0.30
STPMAX 1.00
DUMPR ANO-14.Hi
DEVICE 1
WINDOW 0 0. -100. 1280. 1024. 1100.
GRAPH 1 170. 300. 0. 625. 820. 10. 5 TIME CELSIUS
GRAPH 2 765. 300. 0. 1220. 820. 10. 5 TIME FIRE_SIZE (kW)
LABEL 1 970. 960. 0. 1231. 1005. 10. 15 00:00:00 0. 0.
LABEL 2 690. 960. 0. 987. 1005. 10. 13 TIME_ [SEC] 0. 0.
TEMPERA 0 0 0 0 1 1 U
HEAT 0 0 0 0 2 1 U
-44-
VERSN 3 Fire Zone 99-M, 400 kW fire, Door Closed
TIMES 3600 60 60 60 0
TAMB 298. 101300. 0.0
EAMB 298. 101300. 0.0
HI/F 0.0
WIDTH 10.56
DEPTH 7.72
HEIGH 3.65
HVENT 1 2 1 1.0 0.15 0.0 0.0
CEILI CONCRETE
WALLS CONCRETE
FLOOR CONCRETE
CHEMI 16. 10. 12. 24000000. 298. 388. 0.2
LFBO 1
LFBT 2
FPOS -1.0 -1.0 0.0
FTIME 30.0 60.0 93.0
FHIGH 0.5 0.5 0.5
FAREA 0.5 0.5 0.5
FQDOT 0.0 42210 168840 400000
CJET OFF
CO 0.14 0.14 0.14
OD 0.05 0.05 0.05
HCR 0.30 0.30 0.30
STPMAX 1.00
DUMPR ANO-15.Hi
DEVICE 1
WINDOW 0 0. -100. 1280. 1024. 1100.
GRAPH 1 170. 300. 0. 625. 820. 10. 5 TIME CELSIUS
GRAPH 2 765. 300. 0. 1220. 820. 10. 5 TIME FIRE_SIZE (kW)
LABEL 1 970. 960. 0. 1231. 1005. 10. 15 00:00:00 0. 0.
LABEL 2 690. 960. 0. 987. 1005. 10. 13 TIME_ [SEC] 0. 0.
TEMPERA 0 0 0 0 1 1 U
HEAT 0 0 0 0 2 1 U
-45-
VERSN 3 Fire Zone 99-M, 500 kW fire, Door Closed
TIMES 3600 60 60 60 0
TAMB 298. 101300. 0.0
EAMB 298. 101300. 0.0
HI/F 0.0
WIDTH 10.56
DEPTH 7.72
HEIGH 3.65
HVENT 1 2 1 1.0 0.15 0.0 0.0
CEILI CONCRETE
WALLS CONCRETE
FLOOR CONCRETE
CHEMI 16. 10. 12. 24000000. 298. 388. 0.2
LFBO 1
LFBT 2
FPOS -1.0 -1.0 0.0
FTIME 30.0 60.0 104.0
FHIGH 0.5 0.5 0.5
FAREA 0.5 0.5 0.5
FQDOT 0.0 42210 168840 500000
CJET OFF
CO 0.14 0.14 0.14
OD 0.05 0.05 0.05
HCR 0.30 0.30 0.30
STPMAX 1.00
DUMPR ANO-16.Hi
DEVICE 1
WINDOW 0 0. -100. 1280. 1024. 1100.
GRAPH 1 170. 300. 0. 625. 820. 10. 5 TIME CELSIUS
GRAPH 2 765. 300. 0. 1220. 820. 10. 5 TIME FIRE_SIZE (kW)
LABEL 1 970. 960. 0. 1231. 1005. 10. 15 00:00:00 0. 0.
LABEL 2 690. 960. 0. 987. 1005. 10. 13 TIME_ [SEC] 0. 0.
TEMPERA 0 0 0 0 1 1 U
HEAT 0 0 0 0 2 1 U
-46-
VERSN 3 Fire Zone 98-J, Electrical Cabinet Fire, Test # 23, Vent Open
TIMES 3600 60 60 60 0
TAMB 298. 101300. 0.0
EAMB 298. 101300. 0.0
HI/F 0.0
WIDTH 2.76
DEPTH 18.28
HEIGH 3.65
HVENT 1 2 1 0.9144 0.6096 0.0 0.0
CEILI CONCRETE
WALLS CONCRETE
FLOOR CONCRETE
CHEMI 16. 10. 12. 24000000. 298. 388. 0.2
LFBO 1
LFBT 2
FPOS -1.0 -1.0 0.0
FTIME 90.0 156.0 372.0 450.0 525.0 630.0 720.0 780.0 900.0
FHIGH 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5
FAREA 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5
FQDOT 0.0 40000 85000 70000 690000 600000 900000 1235000 925000 1050000
300000
CJET OFF
CO 0.14 0.14 0.14 0.14 0.14 0.14 0.14 0.14 0.14
OD 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05
HCR 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30
STPMAX 1.00
DUMPR ANO-17.Hi
DEVICE 1
WINDOW 0 0. -100. 1280. 1024. 1100.
GRAPH 1 170. 300. 0. 625. 820. 10. 5 TIME CELSIUS
GRAPH 2 765. 300. 0. 1220. 820. 10. 5 TIME FIRE_SIZE (kW)
LABEL 1 970. 960. 0. 1231. 1005. 10. 15 00:00:00 0. 0.
LABEL 2 690. 960. 0. 987. 1005. 10. 13 TIME_ [SEC] 0. 0.
TEMPERA 0 0 0 0 1 1 U
HEAT 0 0 0 0 2 1 U
-47-
VERSN 3 Fire Zone 98-J, Electrical Cabinet Fire, Test # 23, Vent Closed
TIMES 3600 60 60 60 0
TAMB 298. 101300. 0.0
EAMB 298. 101300. 0.0
HI/F 0.0
WIDTH 2.76
DEPTH 18.28
HEIGH 3.65
HVENT 1 2 1 0.6096 0.3048 0.0 0.0
CEILI CONCRETE
WALLS CONCRETE
FLOOR CONCRETE
CHEMI 16. 10. 12. 24000000. 298. 388. 0.2
LFBO 1
LFBT 2
FPOS -1.0 -1.0 0.0
FTIME 90.0 156.0 372.0 450.0 525.0 630.0 720.0 780.0 900.0
FHIGH 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5
FAREA 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5
FQDOT 0.0 40000 85000 70000 690000 600000 900000 1235000 925000 1050000
300000
CJET OFF
CO 0.14 0.14 0.14 0.14 0.14 0.14 0.14 0.14 0.14
OD 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05
HCR 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30
STPMAX 1.00
DUMPR ANO-18.Hi
DEVICE 1
WINDOW 0 0. -100. 1280. 1024. 1100.
GRAPH 1 170. 300. 0. 625. 820. 10. 5 TIME CELSIUS
GRAPH 2 765. 300. 0. 1220. 820. 10. 5 TIME FIRE_SIZE (kW)
LABEL 1 970. 960. 0. 1231. 1005. 10. 15 00:00:00 0. 0.
LABEL 2 690. 960. 0. 987. 1005. 10. 13 TIME_ [SEC] 0. 0.
TEMPERA 0 0 0 0 1 1 U
HEAT 0 0 0 0 2 1 U
-48-
VERSN 3 Fire Zone 99-M, Electrical Cabinet Fire, Test # 23, Door Open
TIMES 3600 60 60 60 0
TAMB 298. 101300. 0.0
EAMB 298. 101300. 0.0
HI/F 0.0
WIDTH 10.56
DEPTH 7.72
HEIGH 3.65
HVENT 1 2 1 1.82 2.44 0.0 0.0
CEILI CONCRETE
WALLS CONCRETE
FLOOR CONCRETE
CHEMI 16. 10. 12. 24000000. 298. 388. 0.2
LFBO 1
LFBT 2
FPOS -1.0 -1.0 0.0
FTIME 90.0 156.0 372.0 450.0 525.0 630.0 720.0 780.0 900.0
FHIGH 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5
FAREA 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5
FQDOT 0.0 40000 85000 70000 690000 600000 900000 1235000 925000 1050000
300000
CJET OFF
CO 0.14 0.14 0.14 0.14 0.14 0.14 0.14 0.14 0.14
OD 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05
HCR 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30
STPMAX 1.00
DUMPR ANO-19.Hi
DEVICE 1
WINDOW 0 0. -100. 1280. 1024. 1100.
GRAPH 1 170. 300. 0. 625. 820. 10. 5 TIME CELSIUS
GRAPH 2 765. 300. 0. 1220. 820. 10. 5 TIME FIRE_SIZE (kW)
LABEL 1 970. 960. 0. 1231. 1005. 10. 15 00:00:00 0. 0.
LABEL 2 690. 960. 0. 987. 1005. 10. 13 TIME_ [SEC] 0. 0.
TEMPERA 0 0 0 0 1 1 U
HEAT 0 0 0 0 2 1 U
-49-
VERSN 3 Fire Zone 99-M, Electrical Cabinet Fire, Test # 23, Door Closed
TIMES 3600 60 60 60 0
TAMB 298. 101300. 0.0
EAMB 298. 101300. 0.0
HI/F 0.0
WIDTH 10.56
DEPTH 7.72
HEIGH 3.65
HVENT 1 2 1 1.0 0.15 0.0 0.0
CEILI CONCRETE
WALLS CONCRETE
FLOOR CONCRETE
CHEMI 16. 10. 12. 24000000. 298. 388. 0.2
LFBO 1
LFBT 2
FPOS -1.0 -1.0 0.0
FTIME 90.0 156.0 372.0 450.0 525.0 630.0 720.0 780.0 900.0
FHIGH 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5
FAREA 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5
FQDOT 0.0 40000 85000 70000 690000 600000 900000 1235000 925000 1050000
300000
CJET OFF
CO 0.14 0.14 0.14 0.14 0.14 0.14 0.14 0.14 0.14
OD 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05
HCR 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30
STPMAX 1.00
DUMPR ANO-20.Hi
DEVICE 1
WINDOW 0 0. -100. 1280. 1024. 1100.
GRAPH 1 170. 300. 0. 625. 820. 10. 5 TIME CELSIUS
GRAPH 2 765. 300. 0. 1220. 820. 10. 5 TIME FIRE_SIZE (kW)
LABEL 1 970. 960. 0. 1231. 1005. 10. 15 00:00:00 0. 0.
LABEL 2 690. 960. 0. 987. 1005. 10. 13 TIME_ [SEC] 0. 0.
TEMPERA 0 0 0 0 1 1 U
HEAT 0 0 0 0 2 1 U
-50-
VERSN 3 Fire Zone 98-J, Electrical Cabinet Fire, Test # 24, Vent Open
TIMES 3600 60 60 60 0
TAMB 298. 101300. 0.0
EAMB 298. 101300. 0.0
HI/F 0.0
WIDTH 2.76
DEPTH 18.28
HEIGH 3.65
HVENT 1 2 1 0.9144 0.6096 0.0 0.0
CEILI CONCRETE
WALLS CONCRETE
FLOOR CONCRETE
CHEMI 16. 10. 12. 24000000. 298. 388. 0.2
LFBO 1
LFBT 2
FPOS -1.0 -1.0 0.0
FTIME 150.0 270.0 450.0 480.0 519.0 612.0 720.0 810.0 840.0
FHIGH 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5
FAREA 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5
FQDOT 0.0 20000 600000 1200000 1300000 1000000 600000 190000 100000 0.0
CJET OFF
CO 0.14 0.14 0.14 0.14 0.14 0.14 0.14 0.14 0.14
OD 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05
HCR 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30
STPMAX 1.00
DUMPR ANO-21.Hi
DEVICE 1
WINDOW 0 0. -100. 1280. 1024. 1100.
GRAPH 1 170. 300. 0. 625. 820. 10. 5 TIME CELSIUS
GRAPH 2 765. 300. 0. 1220. 820. 10. 5 TIME FIRE_SIZE (kW)
LABEL 1 970. 960. 0. 1231. 1005. 10. 15 00:00:00 0. 0.
LABEL 2 690. 960. 0. 987. 1005. 10. 13 TIME_ [SEC] 0. 0.
TEMPERA 0 0 0 0 1 1 U
HEAT 0 0 0 0 2 1 U
-51-
VERSN 3 Fire Zone 98-J, Electrical Cabinet Fire, Test # 24, Vent Closed
TIMES 3600 60 60 60 0
TAMB 298. 101300. 0.0
EAMB 298. 101300. 0.0
HI/F 0.0
WIDTH 2.76
DEPTH 18.28
HEIGH 3.65
HVENT 1 2 1 0.6096 0.3048 0.0 0.0
CEILI CONCRETE
WALLS CONCRETE
FLOOR CONCRETE
CHEMI 16. 10. 12. 24000000. 298. 388. 0.2
LFBO 1
LFBT 2
FPOS -1.0 -1.0 0.0
FTIME 150.0 270.0 450.0 480.0 519.0 612.0 720.0 810.0 840.0
FHIGH 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5
FAREA 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5
FQDOT 0.0 20000 600000 1200000 1300000 1000000 600000 190000 100000 0.0
CJET OFF
CO 0.14 0.14 0.14 0.14 0.14 0.14 0.14 0.14 0.14
OD 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05
HCR 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30
STPMAX 1.00
DUMPR ANO-22.Hi
DEVICE 1
WINDOW 0 0. -100. 1280. 1024. 1100.
GRAPH 1 170. 300. 0. 625. 820. 10. 5 TIME CELSIUS
GRAPH 2 765. 300. 0. 1220. 820. 10. 5 TIME FIRE_SIZE (kW)
LABEL 1 970. 960. 0. 1231. 1005. 10. 15 00:00:00 0. 0.
LABEL 2 690. 960. 0. 987. 1005. 10. 13 TIME_ [SEC] 0. 0.
TEMPERA 0 0 0 0 1 1 U
HEAT 0 0 0 0 2 1 U
VERSN 3 Fire Zone 99-M, Electrical Cabinet Fire, Test # 24, Door Open
TIMES 3600 60 60 60 0
TAMB 298. 101300. 0.0
EAMB 298. 101300. 0.0
HI/F 0.0
WIDTH 10.56
DEPTH 7.72
HEIGH 3.65
HVENT 1 2 1 1.82 2.44 0.0 0.0
CEILI CONCRETE
WALLS CONCRETE
FLOOR CONCRETE
CHEMI 16. 10. 12. 24000000. 298. 388. 0.2
LFBO 1
LFBT 2
FPOS -1.0 -1.0 0.0
FTIME 150.0 270.0 450.0 480.0 519.0 612.0 720.0 810.0 840.0
FHIGH 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5
FAREA 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5
FQDOT 0.0 20000 600000 1200000 1300000 1000000 600000 190000 100000 0.0
CJET OFF
CO 0.14 0.14 0.14 0.14 0.14 0.14 0.14 0.14 0.14
OD 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05
HCR 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30
STPMAX 1.00
DUMPR ANO-23.Hi
DEVICE 1
WINDOW 0 0. -100. 1280. 1024. 1100.
GRA
-2-
-2-
ENCLOSURE 2
Phase 3 SDP Analysis: Arkansas Nuclear One Unit 1 (ANO-1)
Lack of Adequate Procedures for Manual Actions to Achieve Post-Fire
Safe Shutdown Following Fire Damage in Fire Zones 98J and 99M
1. Performance Deficiency
The Arkansas Nuclear One Unit 1 (ANO-1) fire zone 98-J (Diesel Generator Corridor)
and fire zone 99-M (North Electrical Switchgear Room) did not meet regulatory
requirements for separation of electric cables and equipment of redundant trains of
systems necessary to achieve post-fire safe shutdown. The licensee did not have
adequate procedures for manual actions to achieve post-fire safe shutdown following a
fire in fire zones 99-J and 98-M. This condition has existed since the issue was
identified as Unresolved Item 50-313;368/0106-02 in the Inspection Report 50-
313;368/01-06, August 20, 2001.
2. Fire Scenario
The primary combustibles in the ANO-1fire zones 98-J and 99-M are the safety-related
non-qualified IEEE-383 electrical cables routed in open cable trays that are located
above numerous potential ignition sources. The height of the lowest cable tray in fire
zone 98-J is approximately 6 ft. from the floor; while in the case of fire zone 99-M, the
height of the lowest cable tray from the floor is about 8 ft. In fire zone 98-J, the potential
ignition sources include a battery charger, 480V motor control centers, 125V DC
distribution panels, wall-mounted electrical cabinets, emergency ventilation units, and an
emergency chiller unit (VUC4A/C51). The potential ignition sources in fire zone 99-M
include an air-cooled transformer (X6), a 120V instrument transformer (X62), 4.16kV
switchgear cabinets, 480V motor control centers, a 480V load center, inverter cabinets,
and ventilation units. Other potential ignition sources, such as a power cable failure in a
tray, or other electrical originated failures (in distribution panels, circuit boards, electrical
wiring, internal cable fault, electrical circuit fault in switchgear cabinets, etc.) leading to
ignition of the in-situ combustibles (cables), are considered in the fire scenario. Other
ignition sources such as hot work (welding) or a limited 100-lb transient combustible
source are also possible, but are not considered within the scope of this analysis.
The combustible loading in fire zone 98-J consists of mostly cables in the cable trays.
According to licensee-provided information and calculations, the fire duration in fire zone
98-J was estimated to be 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> and 15 minutes by considering all available in-situ
combustibles and the potential 100-lb transient combustible source. The combustible
loading in fire zone 99-M also consists primarily of cable insulation in open cable trays.
Considering all available in-situ combustibles and a potential 100-lb transient
combustible source, the fire duration in 99-M was estimated to be 30 minutes.
-3-
-3-
The credible fire scenario is based on postulating that a fire develops from any one of
the potential ignition sources, if undetected and unsuppressed (i.e., no immediate
intervention from plant operators), would grow to a rate of heat release of 400 kW (or
380 BTU/s) and ignite the cable insulation of electrical cables resulting in challenging
fires. The Diesel Generator Corridor in fire zone 98-J is provided with smoke detection
and a partial-coverage automatic water suppression system that is actuated by
crosszoned smoke and in-tray linear heat detectors. The ionization smoke detectors are
provided at the ceiling level that only alarms in the Main Control Room (MCR). The
linetype heat detectors (trade named Protectowire) are installed on the top of the cables
in each cable tray, and also alarm in the MCR. The automatic deluge sprinkler system
provides partial protection to the fire zone 98-J, and will activate upon receiving
successful cross-zone detection signals from both of the smoke and linear heat
detectors. A fire hose reel and portable carbon dioxide extinguishers are located in the
vicinity of the fire zone for manual fire fighting purposes when needed. Fire zone 98-J is
normally unoccupied except for inspections, shift tours and maintenance activities. The
fire zone 99-M (North Electrical Switchgear Room) is only protected with a smoke
detection system. The smoke detectors are provided at the ceiling level which alarm in
the MCR. There are no fixed automatic fire suppression systems in this switchgear
room. A fire hose reel and portable carbon dioxide extinguishers are also provided in
the vicinity of the fire zone for manual fire fighting purposes when needed. Fire zone
99-M is normally unoccupied except for inspections, shift tours and maintenance
activities.
In the fire scenario development, it is assumed that a credible fire starts from a specific
ignition source (e.g., transformers, electrical cabinets, 4.16kV switchgear, 480 V motor
control centers, 480V load center, 125V DC distribution panels, or cables) and has
sufficient flame spread (i.e., flame height and radius) to ignite a cable tray closest to the
ignition source. The SPLB fire hazards and fire modeling analyses (see ADAMS
Accession #ML021490005*, #ML021990405*) postulated that energetic electrical faults
in electrical cabinets, producing a fire with heat release rate (HRR) of 400kW or greater,
can lead to fire growth and subsequent fire damage to target cables depending on the
ventilation conditions in the compartment. Two different cases of fire compartment
conditions were considered to define the fire damaging scenarios for the two fire zones:
(1) vent open and closed in Fire Zone 98-J, and (2) door open and closed in Fire Zone
99-M.
The CFAST (Consolidated Model of Fire Growth and Smoke Transport) computer code
was used to model the fire growth of fire involving electrical cabinet and equipment that
would lead to a challenging fire in the fire zones 98-J and 99-M. In each of the fire
scenarios, a range of HRR curves from 200 kW to 500 kW were used as input to the
CFAST fire modeling analyses because no direct data on the burning of the specific
electrical ignition sources at full or intermediate scale were available. As documented in
NUREG/CR-4527, the selected range of HRR curves were developed for electrical
cabinet fires from full-scale fire tests conducted on electrical cabinets in a large (e.g.,
actual control room size) enclosure. In the fire modeling analyses, the fire was assumed
to develop with a t2 fast fire growth rate due to the electrically energized fire
environment (see ADAMS Accession #ML021990405*). It is also assumed that there is
complete combustion and an ample supply of oxygen for the fire with the given HRR.
-4-
-4-
In modeling the fire growth and damage potential, results of SPLB fire modeling
analyses show that fires with HRR of 400kW could damage the overhead cables in fire
zone 98-J with open vent conditions, and in fire zone 99-M with closed door conditions.
In the fire scenario for fire zone 98-J with open vent conditions, the smoke layer
temperature reaches 425 F in approximately 19 minutes. In the case of fire zone 99-
M with closed door conditions, the smoke layer temperature reaches 425 F in
approximately 10 minutes. The limiting temperature of 425 0F was used in the fire
modeling analyses because this temperature condition can cause failure of non-IEEE-
383 rated cables. The results of the fire modeling analyses also indicate that fires with
HRR of 200 kW and 300 kW in the two fire zones tend to become ventilation limited and
decay with time. A fire with HRR of 200kW could only result in a maximum smoke layer
temperature of 305 0F in about one hour for the fire zone 98-J with open vent conditions.
This result indicates that the overhead cables may remain undamaged in fire zone 98-J
for an hour under the postulated conditions.
Based on results of the fire hazards analysis, SPLB fire protection staff also postulated
a fire scenario involving a lube oil spill fire resulting from a breach or leak in the lube oil
system for the emergency chiller chilled water pump located in fire zone 98-J. The fire
modeling analysis for this scenario indicates that a single gallon of lube oil spill, if
ignited, could form a pool fire with a diameter of approximately 1.5 feet, flame height of
6 feet, and burn duration of 7.5 minutes. The flame height of the postulated pool fire is
sufficiently high to impinge on the cable insulation of the non-IEEE-383 rated cables on
the lowest cable tray that is located about 6 feet from the floor. It was concluded that
the turbulent diffusion flame impingement on the cables would cause potential ignition
and flame spread along the cable trays, and thereby further increases the HRR in the
fire zone 98-J.
3. Assumptions
(a) Fire Barriers - In fire zone 98-J, the walls and doors are 3-hour rated fire barriers. A
one-hour rated barrier surrounds the Red train AC instrumentation power supply cables,
while other Red train power cables in fire zone 98-J are unprotected. The Red train
redundant cables are not separated from the Green train cables by a minimum of 20
feet distance free of intervening combustibles. In fire zone 99-M, the Red train cables
are not protected with one-hour rated barrier, and are not separated from the Green
train cables by a minimum of 20 feet distance free of intervening combustibles. As
such, the cables in both fire zones could be damaged by a floor based fire.
(b) Automatic Fire Suppression - The East portion of fire zone 98-J is protected by a
cross-zoned, pre-action deluge system that is actuated by cross-zoned smoke and
intray linear heat detectors. Periodic surveillance is performed on the cable tray
detection system and room smoke detection system to ensure that the suppression
system remains operable. The sprinkler heads in the corridor are open heads, and
water will be available as soon as the sprinkler valve opens in approximately 5 seconds
(according to manufacturers information). The suppression system response time is
assumed to be approximately 7 minutes because the actuation time for the line-type
heat detection system to sense a temperature of 1900F was estimated to be less than 7
minutes. Therefore, the raceways that required more than 10 minutes to sustain
damage can be assumed to be protected by the suppression system. The probability of
pre-action sprinkler system being unavailable is assumed to be 0.05 for the normal
-5-
-5-
operating state based on the EPRI database (EPRI FIVE report, page 10.3-7). This
unavailability value includes the consideration for failure of the system to operate on
demand and the system being out of service at the time of a fire (due to shut control
valve, etc.). In fire zone 99-M, no automatic fire suppression system is provided.
(c) Fire Detection and Manual Fire Suppression - Both fire zones 98-J and 99-M are
equipped with ionization detection systems that will detect fires in the incipient stages
and provide alarm conditions in the Main Control Room (MCR). Alarms from the
ionization detection system would result in the dispatch of an operator to investigate any
of the two fire zones. The central fire brigade locker is located one elevation above the
fire zones 98-J and 99-M, and therefore, the travel time of the fire brigade from the
locker to the fire scene is considered to be reasonably short.
Based on recent fire drills performed on fire zone 100-N, which is adjacent to fire zone
99-M, the response times of the entire fire brigade arriving at the fire zone averaged
less than 10 minutes. There are two access points to the fire zones, which are easily
accessible by the fire brigade response team. Based on these factors, it was assumed
that any fire scenario requiring greater than 20 minutes to sustain cable damage may be
suppressed by the fire brigade.
The fire-induced core damage frequency equation for the fire zones can be defined as
follows:
FCDF = Fi * Sf * P1 * P2 * P3
where: Fi = Fire ignition frequency of ignition source
Sf = Severity factor for a challenging fire
P1 = Probability of automatic fire suppression system being unavailable
P2 = Failure probability of manual suppression by fire brigade
P3 = Conditional core damage probability, with or without recovery actions
4: Fire Ignition Frequencies
The various ignition sources in the fire zones 98-J and 99-M respectively, and their
associated fire ignition frequency estimates, as calculated using the EPRI FIVE
methodology and listed on the Ignition Source Data Sheet (ISDS) for the two ANO-1 fire
zones, are shown below:
-6-
-6-
Fire Zone 98-J
Ignition Sources
Generic
Frequency
WFI
ISDS Ignition
Frequency
Electrical Cabinets
1.9 E-2
1
1.01 E-1
1.9 E -3
Battery Charger
4.0 E-3
2
9.52 E-2
7.6 E -4
Ventilation Subsystems
9.5 E-3
2
1.12 E-2
2.1 E-4
Fire Protection Panels
2.4 E-3
2
2.33 E-2
1.1 E-4
Emergency Chiller Pump
9.5 E-3
2
2.80 E-3
5.3 E-5
Fire Zone 99-M
Ignition Sources
Generic
Frequency
WFI
ISDS Ignition
Frequency
Electrical Cabinets
1.5 E-2
0.25
1.0
3.8 E-3
Transformers
7.9 E-3
2
2.04 E-2
3.2 E-4
Ventilation Subsystems
9.5 E-3
2
5.60 E-3
1.1 E-4
The ISDS ignition frequency estimates of each identified ignition source were derive
based on adjusting the generic fire ignition frequencies by a location weighting
facto(WFL) and an ignition source weighting factor (WFI). The generic fire ignition
frequencies used in this analysis were based on the EPRI database (EPRI Fire PRA
Implementation Guide, pages 4-7 & 4-8, Table 4.2). A comparison of the generic fire
ignition frequency estimates against the NRC updated fire events database (Houghton,
RES) showed that the generic frequency estimates were slightly higher.
With the exception of the electrical cabinets, all of the above listed sources were
considered as Plant Wide components and therefore, were assigned a WFL = 2 (i.e.,
number of units per site). For fire zone 98-J in the auxiliary building, the electrical
cabinets were assigned WFL = 1 because of the number of units per site divided by the
number of auxiliary buildings. For fire zone 99-M (which is a switchgear room), the
electrical cabinets were assigned WFL = 0.25 because of 2 units per site divided by 8
switchgear rooms.
The weighting factor, WFI, for plant-wide components is obtained by dividing the number
of components in the specified room by the total number of components in the plant. In
fire zone 98-J, WFI = 0.101 is derived for the electrical cabinets by dividing 147 cabinets
in the corridor by the total number of 1452 cabinets in the auxiliary building. Similarly,
the WFI factors for the other ignition sources in both fire zones 98-J and 99-M were
derived from plant-specific data (as provided in ANO-1 licensee response package). In
fire zone 98-J, there are 4 ventilation subsystems, whereas there are two ventilation
units in fire zone 99-M. In fire zone 98-J, there are 2 fire protection panels, whereas
there are none in fire zone 99-M. In fire zone 98-J, there are no transformers, whereas
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there are two transformers in fire zone 99-M. In fire zone 98-J, there are 2 battery
chargers, whereas there are none in fire zone 99-M. Based on licensee Calculation 85-
E-0053-47, the total number of ventilation subsystems is 357, the total number of fire
protection panels is 86, the total number of transformers is 98, and the total number of
battery chargers is 21 (increased from 19 due to recent modifications).
The ignition frequency of the emergency chiller pump was derived using the generic
frequency for the ventilation subsystems because there was no plant-specific ignition
frequency data. The WFI factor for the emergency chiller pump was based on a single
ventilation subsystem in the fire zone. Therefore, WFI = 1/357 = 2.8 E-3 was used in
deriving the ignition frequency for the emergency chiller pump. The emergency chiller
unit in fire zone 98-J is a standby component and its operability is demonstrated on a
monthly basis by a surveillance test with duration of less than 30 minutes. The test is
performed by Operations personnel who are trained fire brigade members.
5: Conditional Core Damage Probability (CCDP)
In the various fire scenarios considered (i.e., each scenario initiated by a different
ignition source), conditional core damage probabilities (CCDPs) were calculated for the
two fire zones using the ANO-1 IPEEE fire risk model for two cases: (a) no operator
recovery actions were credited, and (b) credit for operator actions to recover the
Emergency Feedwater (EFW) system and other required actions for safe shutdown. In
both cases, the CCDP calculations were performed for two conditions: (i) one Red
equipment train is available to perform mitigating functions, and (ii) both Red and Green
equipment trains are unavailable due to the severe, challenging fire. In the event that
both redundant equipment trains in a fire zone are affected by fire, the CCDPs would be
dominated by operator actions to achieve safe shutdown outside of the main control
room.
In the licensees PSA analyses to estimate the CCDPs with no operator recovery actions
(ANO-1 Calculations 02-E-0004-01 and 02-E-0004-02), the following operator recovery
actions were not credited (i.e., set to logical TRUE in the cutsets of the risk model) to
analyze the impact of inability to accomplish these operator actions outside of the
control room by operations during the fire:
1.
Operator fails to isolate ICW after automatic SW isolation fails on ES
2.
Operator fails to start and control EFW pump P-7A manually when offsite
power is available
3.
Operator fails to start and control EFW pump P-7B from control room
when offsite power is available
4.
Operator fails to open breaker locally at A1 from the unit auxiliary
transformer and close the breaker from startup transformer SUT1
5.
Operator fails to manually close breaker 152-308 or 152-408 for EDG
recovery
6.
Operator fails to de-energize CV-2646 and CV-2648 (with consideration
of hot-short probability for CV-2646 or CV-2648)
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As shown in the ANO-1 Calculations 02-E-0004-01 and 02-E-0004-02, the CCDPs
calculated for the two fire zones for the different fire scenarios are provided below:
Fire Zone 98-J
East Area
CCDP with No Operator
Recovery
CCDP with Operator
Recovery
All Redundant Cable
Trains Failed
1.13 E-2
2.18 E-4
Red Train Protected
8.10 E-3
1.97 E-4
Fire Zone 98-J
West 1 Area
CCDP with No Operator
Recovery
CCDP with Operator
Recovery
All Redundant Cable
Trains Failed
5.38 E-4
1.39 E-4
Red Train Protected
5.38 E-4
1.39 E-4
Fire Zone 98-J
West 2 Area
CCDP with No Operator
Recovery
CCDP with Operator
Recovery
All Redundant Cable
Trains Failed
2.49 E-3
1.85 E-4
Red Train Protected
5.38 E-4
1.26 E-4
Fire Zone 99-M
CCDP with No Operator
Recovery
CCDP with Operator
Recovery
All Redundant Cable
Trains Failed
5.76 E-2
1.27 E-3
Red Train Protected
7.96 E-3
8.32 E-4
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6. Integrated Assessment of Fire-Induced Core Damage Frequency
The fire-induced CDF estimate for fire in the fire zones 98-J and 99-M with no operator
recovery actions is calculated as shown below:
Fire Zone 98-J
Ignition Sources
Fi
Sf
P1
P2
P3
FCDF
Electrical Cabinets
1.9 E-3
0.75
0.05
0.5
9.2E-3
3.3E-7
Battery Chargers
7.6 E-4
0.75
0.05
0.5
9.2E-3
1.3E-7
Ventilation Subsystems
2.1 E-4
0.08
0.05
0.5
9.2E-3
3.0E-9
Fire Protection Panels
1.1 E-4
0.12
0.05
0.5
9.2E-3
3.0E-9
Emergency Chiller Pump
5.3E-5
0.08
0.05
0.5
1.4E-2
1.0E-9
Total CDF
4.7E-7
Fire Zone 99-M
Ignition Sources
Fi
Sf
P1
P2
P3
FCDF
Electrical Cabinets
3.8 E-3
0.12
1.0
0.5
5.8E-2
1.3E-5
Transformers
3.2 E-4
0.10
1.0
0.5
5.8E-2
9.3E-7
Ventilation Subsystems
1.1 E-4
0.08
1.0
0.5
5.8E-2
2.6E-7
Total CDF
1.4E-5
(a) Severity Factors, Sf - A fire severity factor is a fractional value (between 0 and 1) that
is used to adjust fire frequency estimates to reflect some specific mitigating pattern of
behavior of the fire event. The severity factor is applied to reflect a split in large versus
small fires. In the absence of plant-specific information, the severity factors for the
electrical cabinets, ventilation systems, and fire protection panels were based on the
EPRI Fire PRA Implementation Guide (FPRAIG), December 1995 (Section D.3). The
FPRAIG severity factors ranged from 0.08 to 0.2, and engineering judgment was used
to determine these severity factors.
In the case of the electrical cabinets and battery chargers in fire zone 98-J, the EPRI
FPRAIG did not provide specific severity factor values for electrical cabinets and battery
chargers in the Auxiliary building. Therefore, the licensees assigned severity factor of
0.75 was assumed in this analysis.
(b) Probability of automatic suppression system being unavailable, P1 - As discussed in
Section 3(b), the probability of pre-action sprinkler system in fire zone 98-J being
unavailable is assumed to be 0.05 for the normal operating state based on the EPRI
database (EPRI FIVE report, page 10.3-7). This unavailability value include the
consideration for failure of the system to operate on demand and the system being out
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of service at the time of a fire (due to shut control valve, etc.). In fire zone 99-M, no
automatic fire suppression system is provided. Therefore, the P1 value was assumed to
be 1.0.
(c) Manual Suppression by Fire Brigade, P2 - Recent fire drills performed on fire zone
100-N, which is adjacent to fire zone 99-M, indicated that the response times of the
entire fire brigade arriving at the fire zone averaged less than 10 minutes. There are
two access points to the fire zones, which are easily accessible by the fire brigade
response team.
Based on these considerations, it was assumed that any fire scenario requiring greater
than 20 minutes to sustain cable damage may be suppressed by the fire brigade.
However, the SPLB fire modeling analyses indicate that severe fires with HRR greater
than 400 kW in fire zones 98-J and 99-M could cause damage to the overhead cables in
approximately 19 minutes and 10 minutes, respectively. Therefore, the failure
probability of manual suppression by the fire brigade associated with severe fires was
estimated to be 0.5 in this risk analysis.
(d) Conditional Core Damage Probability, P3 - For the fire scenarios in fire zone 98-J
involving ignition of the electrical cabinets, battery chargers, ventilation systems, and fire
protection panels, it is assumed that one equipment train would be available to perform
mitigating functions because a one-hour rated barrier surrounds the Red train AC
instrumentation power supply cables. Although other Red train power cables in fire
zone 98-J are unprotected, the estimated time of 19 minutes to cable damage allows the
arrival of the fire brigade in 10 minutes to control the fire. It is not likely that a fire from
these sources would damage both equipment trains at the same time. Therefore, the
CCDP estimate of 9.2E-3 (summed over all portions of fire zone 98-J) was used in the
risk analysis of the fire scenarios involving these ignition sources. In the case of the fire
scenario involving the emergency chiller pump, the pool fire with a flame height of 6 feet
and burn duration of 7.5 minutes was postulated to impinge on the cable insulation of
the non-IEEE-383 rated cables on the lowest cable tray that is located about 6 feet from
the floor. It was concluded that the turbulent diffusion flame impingement on the cables
would cause potential ignition and flame spread along the cable trays, and thereby
further increases the HRR in the fire zone 98-J. It is likely that a fire from this pool fire
may damage both equipment trains at the same time. Therefore, the CCDP estimate of
1.4E-2 (summed over all portions of fire zone 98-J) was used in the risk analysis of this
fire scenario.
For the fire scenarios in fire zone 99-M involving ignition of the electrical cabinets,
transformers, and ventilation systems, it is assumed that both equipment trains would
not be available to perform mitigating functions because the Red train cables are not
protected with one-hour rated barrier, and are not separated from the Green train cables
by a minimum of 20 feet distance free of intervening combustibles. Therefore, the
CCDP estimate of 5.8 E-2 was used in the risk analysis of the fire scenarios in fire zone
98-M.
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7: Incremental Fire-Induced CDF
The baseline CDF (conforming case) for the fire scenarios in the fire zones 98-J and 99-
M with credit of operator recovery actions is calculated by assuming the manual
suppression failure probability of 0.1. This value is used for the manual suppression
capability because it is considered to be appropriate for the entire population of fires,
including severe fires, arising from an ignition source. The fire protection SDP
methodology, which uses the entire population of fires as the basis to derive an ignition
frequency, also uses the probability value of 0.1, in general, for the failure probability of
nondegraded manual suppression capability. The baseline CDF with credit of operator
recovery actions for the conforming-case analyses are shown below:
Fire Zone 98-J
Ignition Sources
Fi
P1
P2
P3
FCDF
Electrical Cabinets
1.9 E-3
0.05
0.1
4.6E-4
4.0E-9
Battery Charger
7.6 E-4
0.05
0.1
4.6E-4
1.0E-9
Ventilation Subsystems
2.1 E-4
0.05
0.1
4.6E-4
5.0E-10
Fire Protection Panels
1.1 E-4
0.05
0.1
4.6E-4
3.0E-10
Emergency Chiller Pump
5.3E-5
0.05
0.1
5.4E-4
1.0E-10
Total CDF
6.0E-9
Fire Zone 99-M
Ignition Sources
Fi
P1
P2
P3
FCDF
Electrical Cabinets
3.8 E-3
1.0
0.1
1.3E-3
4.9E -7
Transformers
3.2 E-4
1.0
0.1
1.3E-3
4.1E-8
Ventilation Subsystems
1.1 E-4
1.0
0.1
1.3E-3
1.4E-8
Total CDF
5.5E-7
Therefore, the incremental CDF changes due to taking credit for operator recovery
actions for fire scenarios in fire zones 98-J and 99-M are estimated as follows:
A. Fire zone 98-J: (4.7E-7) - (6.9E-9) = 4.6E-7
B. Fire zone 99-M: (1.4E-5) - (5.5E-7) = 1.3E-5
CONCLUSION: The change in CDF due to taking credit for operator recovery actions
for fire scenarios in fire zone 98-J is 4.6E-7, and the significance characterization is
GREEN. The change in CDF due to taking credit for operator recovery actions for fire
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scenarios in fire zone 99-M is 1.3E-5, and the significance characterization is
[redacted].
Please note that ML021990405 is Enclosure 1, "Fire Modeling of Fire Zone 98-J,
Emergency Diesel Generator Corridor and 99-M, North Electrical Switchgear Room,
Arkansas Nuclear One - Unit 1, to this letter.
ML021490005 is not provided.