[Federal Register Volume 71, Number 191 (Tuesday, October 3, 2006)]
[Notices]
[Pages 58436-58440]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-16262]
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NUCLEAR REGULATORY COMMISSION
[ Docket No. 50-333]
Entergy Nuclear Operations, Inc.; James A. Fitzpatrick Nuclear
Power Plant; Exemption
1.0 Background
Entergy Nuclear Operations, Inc. (ENO or the licensee) is the
holder of Facility Operating License No. DPR-59, which authorizes
operation of the James A. FitzPatrick Nuclear Power Plant (JAF). The
license provides, among other things, that the facility is subject to
all rules, regulations, and orders of the Nuclear Regulatory Commission
(NRC or the Commission) now or hereafter in effect.
The facility consists of one boiling-water reactor located in
Oswego County, New York.
2.0 Request/Action
Title 10 of the Code of Federal Regulations (10 CFR), Part 50,
Section 50.48, requires that nuclear power plants that were licensed
before January 1, 1979, of which JAF is one, must satisfy the
requirements of 10 CFR Part 50, Appendix R, Section III.G. Subsection
III.G.2 addresses fire protection features for ensuring that one of the
redundant trains necessary to achieve and maintain hot shutdown
conditions remains free of fire damage in the event of a fire.
Subsection III.G.2.c provides use of a 1-hour fire barrier as one means
for complying with this fire protection requirement. ENO proposes that
the absence and/or control of ignition sources, the adequacy of
detection and suppression systems, and the capability of the existing
Hemyc fire wrap in this fire area, satisfy the underlying intent of 10
CFR 50, Appendix R, Subsection III.G.2.c.
In summary, by letter dated July 27, 2005, Agencywide Documents
Access and Management System (ADAMS) accession number ML052210382, as
supplemented on May 17, 2006,
[[Page 58437]]
ADAMS accession number ML061530108, ENO submitted an exemption request
to the NRC for relief from the requirements of Subsection III.G.2.c of
10 CFR 50, Appendix R, specifically, from the 1-hour rating requirement
for the fire wrap in the West Cable Tunnel at JAF.
3.0 Discussion
Pursuant to 10 CFR 50.12, the Commission may, upon application by
any interested person or upon its own initiative, grant exemptions from
the requirements of 10 CFR Part 50 when (1) the exemptions are
authorized by law, will not present an undue risk to public health or
safety, and are consistent with the common defense and security; and
(2) when special circumstances are present. One of these special
circumstances, described in 10 CFR 50.12(a)(2)(ii), is that the
application of the regulation is not necessary to achieve the
underlying purpose of the rule.
The NRC staff examined the licensee's rationale to support the
exemption request and concluded that the existing fire protection
features in and accessible for the specific fire zone referenced for
JAF meet the underlying purpose of 10 CFR 50, Appendix R, Subsection
III.G.2.c. The following technical evaluation provides the basis for
this conclusion.
3.1 Background
On May 29, 2001, the NRC granted the licensee an exemption from the
requirement of Appendix R, Section III.G.2.c, applicable to the West
Cable Tunnel at JAF. Specifically, although III.G.2.c provides the use
of a 1-hour rated fire barrier as a means of ensuring adequate fire
protection for redundant safe shutdown trains in this fire zone, the
licensee identified that the fire barrier material intended to be rated
for 1 hour, in fact demonstrated functionality for 52 minutes during
testing in accordance with American Society for Testing and Materials
E-119 test criteria. The NRC granted the exemption based on supporting
evidence that a 30-minute rated fire barrier, in combination with
existing fire protection features and the absence of significant
combustibles and ignition sources in the area, provided an equivalent
level of protection and satisfied the underlying purpose of the rule.
More than one type of fire barrier is used in this fire area, however
no specific fire barrier type was identified in the exemption itself.
In 2005, the NRC identified Hemyc fire barriers as potentially
nonconforming fire barriers relied on for compliance with fire
protection regulations for 1-hour or 3-hour rated protection at some
licensed nuclear power plants. On April 1, 2005, the NRC staff issued
Information Notice 2005-07, ``Results of HEMYC Electrical Raceway Fire
Barrier System Full Scale Fire Testing'' (ML050890089), identifying the
concern. On April 10, 2006, the NRC staff issued Generic Letter 2006-
03, ``Potentially Nonconforming Hemyc and MT Fire Barrier
Configurations'' (ML053620142), asking that licensees determine whether
this type of fire barrier is relied on for compliance and, if so, how
compliance is maintained given the potential for nonconformance
observed during recent NRC Hemyc testing (ML051190026).
ENO identified use of Hemyc in the West Cable Tunnel and seeks an
exemption similar to that granted in May 2001 (specified in the current
submittal as applicable to Kaowool FP-60 fire barrier wrap), on the
basis that the existing Hemyc fire barrier in this area is expected to
provide at least 30 minutes of protection for the redundant safe
shutdown trains located there and, in combination with existing fire
protection features and the absence of significant combustibles and
ignition sources in the area, provides an equivalent level of
protection to satisfy the underlying purpose of the rule.
3.2 Existing Fire Protection Features
Fire Area 1C at JAF contains the West Cable Tunnel (Fire Zone [FZ]
CT-1). FZ CT-1 is protected from adjoining fire zones and other plant
areas by 3-hour fire barriers. It has a total area of 13,400 square
feet and contains Division I (Train A) cables for systems relied on for
post-fire safe shutdown. In the event of a fire in this zone, the High
Pressure Coolant Injection System and Residual Heat Removal System
``B'' Train are relied on for hot shutdown of the plant, as well as the
Alternate Shutdown Cooling System ``B'' Train which is relied on for
cold shutdown.
These systems are supported by the ``B'' Train direct current (dc)
power supply and associated heating, ventilating, and air conditioning
equipment. Therefore, the power cable for the air handling unit which
provides proper ventilation for the ``B'' Train dc power supply (or
Battery Room ``B''), is also relied on for safe shutdown and is the
subject of this review.
Hemyc is used to protect approximately 40 feet of the 5-inch
conduit containing this power cable, for compliance with safe shutdown
requirements. Within the 40 feet of Hemyc-wrapped conduit are 3.75 feet
of 5-inch flex-conduit, and an inline pull box approximately 12 inches
by 18 inches by 8 inches. All structural supports are seismically-
qualified and completely wrapped in Hemyc except for a portion of the
base plates, which are bolted to a concrete ceiling.
The licensee describes the Hemyc material used in this application
as consisting of an inner and outer covering of aluminized
Siltemp[supreg].\1\ The licensee states that aluminized Siltemp[supreg]
can be expected to have better heat resistive properties than non-
aluminized Siltemp[supreg] or Refrasil[supreg], since the reflective
coating serves to reflect more radiant energy than the standard
Siltemp[supreg] or Refrasil[supreg].
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\1\ Siltemp[supreg] and Refrasil[supreg] are heat-resistant
fabrics used as an outer covering for Hemyc. Both were tested by the
NRC and determined to be essentially equivalent (ADAMS Accession No.
ML 051190055). Refrasil[supreg] was used during recent NRC Hemyc
tests.
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The licensee identifies the in-situ combustible load for this zone
as cable and fiberglass. Cable is described as making up over 90
percent of the load, with original cables ordered before Institute of
Electrical and Electronics Engineers (IEEE) Standard 383-1974 was
issued. However, the licensee states that the flame retardant
capability of the installed cable was analyzed and determined to be
similar to IEEE 383-1974 rated cable. The fiberglass in this zone is
comprised of a water tank (shower waste tank), piping, and ladders. The
tank is approximately 21 feet from the Hemyc wrap, and the ladders are
stored over 50 feet from the Hemyc wrap. Only the cables have been
identified as significant in-situ ignition sources.
Detection in FZ CT-1 is described by the licensee as an automatic
area-wide early warning smoke detection system monitored in the Main
Control Room. Although the detection system was designed and installed
in accordance with National Fire Protection Standards 72D and 72E, 1979
and 1978 Editions, respectively, the installed system does not meet the
code of record in some cases. However, the deviations from the code
were evaluated by the licensee and determined not to adversely impact
safety performance.
Automatic suppression for this zone is described as consisting of
area-wide sprinklers and in-tray water spray. Manual suppression is
also available within FZ CT-1 and in nearby areas in the form of fire
extinguishers and hose stations.
3.3 Evaluation
Hemyc fire barrier is used to wrap a cable in FZ CT-1 that supplies
power to the air handling unit that supports redundant safe shutdown
equipment
[[Page 58438]]
described in Section 3.2 above. Although this Hemyc was installed with
the intention of providing 1 hour of rated fire protection in
accordance with Appendix R, Subsection III.G.2.c, the licensee has
evaluated the Hemyc configuration for this power cable and requests an
exemption from the 1 hour requirement based on the expectation that the
configuration will provide at least 30 minutes of protection.
Five-inch conduits were not tested in recent Hemyc tests. However,
because the mass of the larger sized conduits used in this application
at JAF should be more resistant to thermal absorption than that of the
4-inch conduits tested, and because this expectation was confirmed
during NRC testing where the smaller sized conduits consistently failed
in less time than the larger sized conduits, the NRC staff expects the
results of the 4-inch conduit tests to be representative of a 5-inch
configuration with some conservatism. The NRC testing was described in
NRC Information Notice 2005-07 and further documented in the Sandia
National Laboratories test reports (ML051190026).
In the NRC tests (described in Section 3.1 above), the 4-inch
conduit was tested with and without cable placed inside. With cable
inside, indication of thermal failure for the 4-inch conduit was
reached at 43 minutes. Therefore, for the rigid 5-inch configuration at
JAF, the NRC staff finds that the test results for the 4-inch conduit
and the additional time margin for thermal failure to occur due to the
larger mass of the 5-inch conduit provides reasonable assurance that
the Hemyc would provide 30 minutes of protection.
The 5-inch cable configuration at JAF also includes a section of
flex-conduit and an in-line pull box. Flex-conduit was not included in
the recent Hemyc tests. However, the licensee provided additional
information regarding this application of flex-conduit. The size and
geometry of the flex-conduit is described as identical to that of the
rigid conduit. However, the weight per unit length of the flex-conduit
(4.7 pounds per foot (lbs/ft)) was determined to be best represented by
the empty 2.5-inch conduit tested (5.1 lbs/ft). Because the initiation
of thermal failure for the 2.5-inch empty conduit was indicated at 41
minutes during the NRC tests, the NRC staff finds that the flex-conduit
configuration at JAF would be expected to provide slightly less than 41
minutes of protection. Because initiation of thermal failure for the 1-
inch filled conduit tested (2.52 lbs/ft) was indicated at 34 minutes
during the NRC tests, the NRC staff finds that the flex-conduit
configuration at JAF would be expected to provide 30 minutes of
protection, with an estimated margin of approximately 10 minutes
(approximately 33 percent margin).
The in-line pull box included in the Hemyc configuration is
approximately 12-inches by 18-inches by 8-inches, and is positioned in-
line with the 5-inch rigid conduit. A larger junction box of the same
shape as the JAF pull box was included in the recent Hemyc tests,
tested both with and without bands. Therefore, the NRC test results for
the junction box should provide a reasonable representation of the
expected performance of the JAF pull box configuration.
In the NRC tests the Hemyc material was wrapped around the junction
box (18-inches by 24-inches by 8-inches) using two Hemyc mats, each
covering 3 sides of the box and stitched together. In the test with
bands, the banding kept both mats in place even though the stitching
failed. The junction box was banded with 2 to 3 bands around each of
the six sides. When tested with the bands, initiation of thermal
failure within the junction box was indicated at 31 minutes following
the onset of the fire. In the test without the bands, initiation of
thermal failure within the junction box was indicated at 15 minutes
following the onset of the fire.
At JAF, the Hemyc material is wrapped around the pull box using one
Hemyc mat covering four sides, with a seam stitched along the length of
one side. The remaining two ends are protected by Hemyc end pieces
stitched in place. Banding is used to keep the four sides secured in
place; however, the banding does not secure the end pieces. The
licensee describes the end pieces as partially secured in place with
the Hemyc that is wrapped around the in-line conduit. However, the NRC
staff is concerned that without banding of the end pieces similar to
banding of all sides during NRC tests, failed stitching would result in
thermal failure at the unbanded end pieces similarly to that
demonstrated during NRC testing of the unbanded junction box.
In the licensee's May 17, 2006, response (ADAMS Accession No.
ML061530108) to the NRC staff's request for additional information
(ADAMS Accession No. ML060860014) regarding the expected performance of
the pull box during a severe fire, the licensee stated that the degree
of thermal shrink observed during NRC testing using Refrasil[supreg]
was more substantial than that observed during subsequent industry
testing using Siltemp[supreg], which is the material used in the JAF
Hemyc configuration. However, this reasoning is not consistent with the
NRC staff's interpretation of the results of the tests. The NRC staff
observed both the NRC and industry tests and analyzed the data from
both tests. The NRC staff observed that the improvements made to the
industry test configuration (including increased collar widths, double
wrapped elbows, and larger overlap area at the joints) may have
resulted in smaller gaps at the joints; however, the resulting thermal
failures were consistent (and sometimes more severe) than those
observed during the NRC tests. In addition, these improvements have not
been incorporated into the JAF pull box configuration. Therefore, the
NRC staff finds no basis to conclude improved performance at the pull
box end piece stitching.
Based on the results of the NRC tests, it appears that the four
banded sides of the pull box would remain protected for approximately
31 minutes. However, the protection provided by the two ends of the
pull box is uncertain. Banding is not used to secure the end pieces of
the JAF pull box as it was during the NRC test of the junction box. The
adjoining Hemyc from the in-line conduit may provide some
reinforcement, but that potential additional protection is uncertain.
Also, the apparent pinched stitching could provide additional Hemyc
material that may improve performance, but again with uncertain
quantification of the potential additional protection. Therefore, based
on the results of the NRC tests and the absence of banding at the two
ends of the JAF pull box, it appears that the conduit within the pull
box would remain protected for 15 to 31 minutes from the onset of a
fire. With additional margin added to the NRC test results to provide
reasonable assurance of protection of the cables inside, the NRC staff
finds that 30 minutes of protection cannot be reasonably expected at
the pull box.
Regarding the licensee's expectation that aluminized
Siltemp[supreg] will improve the heat resistive properties of the JAF
Hemyc configuration, it is not clear to the NRC staff that this
expectation has been quantified or analyzed. In response to the NRC
staff's request for additional information asking for supporting
evidence of this expectation, the licensee referred to the
manufacturer's data. Although this reference confirmed the statement
that, ``(a)luminized Siltemp[supreg] provides thermal reflectivity,''
it also provided a table of Siltemp[supreg] products, including
aluminized Siltemp[supreg] as an entry with a footnote that states,
``Coatings will lose properties as temperature increases.'' In
[[Page 58439]]
addition, the licensee stated that ``(b)ased on the better thermal
reflectivity of the aluminized Siltemp[supreg], less heat transfer will
occur into the Hemyc wrap because it is reflected away.'' However, the
licensee has provided no quantification for any potential reduction in
radiant heat transfer. In addition, the stratification of hot gases
would likely result in the formation of a black body in the vicinity of
the Hemyc configuration (near the ceiling) which would impede radiant
heat transfer. Based on the information provided, the NRC staff is
unable to confirm that the contribution of thermal reflectivity, if
any, would be effective enough to result in a measurable improvement in
Hemyc performance. Therefore, the NRC staff finds no basis for the
expectation of any marked difference in radiant energy reflection
between aluminized and standard Siltemp[supreg] or Refrasil[supreg].
All structural supports used in this application are seismically-
qualified and completely wrapped in Hemyc except for a portion of the
base plates, which are bolted to a concrete ceiling. In response to the
NRC staff's request for additional information, the licensee provided
details on the configuration of the structural support. Although the
area of the exposed portions of the base plates requested was not
provided, the NRC staff is of the opinion that the concrete ceiling
should act as a heat sink for a fire in this area, minimizing the heat
transfer through the supports. Based on the fully-wrapped structural
support system, the NRC staff finds the heat transfer through the
exposed based plates or supports would be insufficient to adversely
impact the functionality of the associated protected cable.
Combustibles and Ignition Sources
The only significant in-situ combustible and ignition source for
this zone is cable. Although these cables were installed before IEEE
Standard 383-1974 was issued, they have been analyzed to determine the
flame retardant capability and shown to be equivalent to IEEE 383-1974
rated cable. The NRC staff has reviewed the licensee's evaluation of
the flame retardant characteristics of the cable installed and finds
acceptable the licensee's determination that a fire in this area will
propagate slowly.
Administrative procedures control transient combustibles, ignition
sources, and hot work in this zone. Procedures are being revised to
incorporate restrictions on hot work in the proximity of the Hemyc wrap
under review, similar to that done for the Kaowool FP-60 fire barrier
wrap.
Detection
An automatic area-wide smoke detection system is installed in this
fire area. If actuated, the detector will initiate an alarm in the Main
Control Room. Because the installed detection system does not meet the
code of record in some cases, the deviations from the code were
evaluated by the NRC staff and found to potentially affect the
availability of the detection system. Therefore, the NRC staff reviewed
the licensee's program to ensure availability of the detection systems
in the event detection is unavailable in FZ CT-1. The NRC staff found
that adequate administrative controls are in effect to apply
compensatory measures if the system is not available and adequate
controls maintain the effectiveness of the detection system. Therefore,
the NRC staff concludes that the detection system code deviations do
not adversely impact safety performance in this zone.
Suppression
Automatic suppression for this zone is supplied by area-wide
sprinklers and an in-tray water spray system. Manual suppression is
also available through hose stations and fire extinguishers located
within the fire zone and in nearby areas. In the event that automatic
or manual suppression systems are out of service, compensatory measures
have been established to protect safe shutdown equipment in FZ CT-1.
Risk Analysis
The licensee reviewed the JAF fire probabilistic risk analysis
database for the air handling unit and the power cable supplying it,
and found that neither are risk significant. If the power cable was
damaged by a fire, and therefore ventilation was lost to the B battery
room, the licensee stated it would take 2 hours for the B battery room
to heat up to the point it would exceed the manufacturer's
qualification of the battery. This allows time to fight the fire and
take corrective actions. Assuming the loss of all the equipment in FZ
CT-1, the licensee estimated the total core damage frequency for a fire
in FZ CT-1 as 7.21E-7/year, based on the JAF Individual Plant
Examination for External Events.
Defense-in-Depth
Part 50 of 10 CFR, Appendix R, section II, states that a licensee's
fire protection program extends the concept of defense-in-depth to fire
protection with the following objectives:
To prevent fires from starting,
To detect rapidly, control, and extinguish promptly those
fires that do occur, and
To provide protection for structures, systems and
components important to safety so that a fire that is not promptly
extinguished by the fire suppression activities will not prevent the
safe shutdown of the plant.
Regulatory Guide 1.174 also identifies factors to be considered
when evaluating defense-in-depth for a risk-informed change.
The NRC staff has evaluated the elements of defense-in-depth used
for fire protection at JAF, applicable to the fire zone under review.
Although the NRC staff finds inadequate basis to support the licensee's
expectation that the existing Hemyc configuration in FZ CT-1 will
provide 30 minutes of protection for the power cable to the air
handling unit relied on for post-fire safe shutdown in the event of a
worst-case fire in FZ CT-1, the NRC staff is reasonably assured that
the absence of significant combustible loading and ignition sources in
the area of the Hemyc configuration and low risk significance
associated with the safe shutdown equipment protected, preclude the
need for withstanding a fire of the magnitude tested in recent NRC
tests. In particular, although the Hemyc configuration applied to the
JAF pull box may not be optimal, the risk significance is low. In
addition, the existing fire protection capabilities for full area
detection, full area suppression, and in-tray suppression, provide
reasonable assurance for prevention of an unmitigated fire. Therefore,
based on the NRC staff's analysis, defense-in-depth is maintained.
Special Circumstances
One of the special circumstances, described in 10 CFR
50.12(a)(2)(ii), is that the application of the regulation is not
necessary to achieve the underlying purpose of the rule. The underlying
purpose of Subsection III.G.2.c of 10 CFR 50, Appendix R, is to ensure
that one of the redundant trains necessary to achieve and maintain hot
shutdown conditions remains free of fire damage in the event of a fire,
and allows the use of a 1-hour fire barrier with fire detectors and an
automatic fire suppression system as one means for complying with this
fire protection requirement. For FZ CT-1, based on the presence of
area-wide smoke detection; the presence of automatic area and in-tray
fire suppression and manual fire suppression; fire barrier protection
at the boundaries of the fire zone; the existing Hemyc configuration in
the fire zone; implementation of transient combustibles controls
including proposed revisions for hot work in the
[[Page 58440]]
vicinity of the Hemyc configuration; and the absence of significant
combustible loading and ignition sources, the NRC staff finds that a 1-
hour rating for the fire barrier protection in this zone is not
necessary to ensure the availability of a redundant train necessary to
achieve and maintain safe shutdown of the plant in the event of a fire
in FZ CT-1. Based upon consideration of the information in the
licensee's Fire Hazards Analysis; administrative controls for transient
combustibles and ignition sources; responses to NRC staff requests for
additional information; previously-granted exemptions for this fire
zone; and the considerations noted above, the NRC staff concludes that
this exemption meets the underlying purpose of the rule. Therefore,
operating in the proposed manner meets the underlying purpose of
Subsection III.G.2.c to 10 CFR 50, Appendix R, and special
circumstances required by 10 CFR 50.12 for the granting of an exemption
from 10 CFR 50 exist.
Authorized by Law
This exemption would allow use of a fire barrier expected to
provide less than 1 hour of fire protection. As stated above, 10 CFR
50.12 allows the NRC to grant exemptions from the requirements of 10
CFR Part 50. The NRC staff has determined that granting of the
licensee's proposed exemption is permissible under the Atomic Energy
Act of 1954, as amended, or the Commission's regulations. Therefore,
the exemption is authorized by law.
No Undue Risk to Public Health and Safety
The underlying purpose of Subsection III.G.2.c of 10 CFR 50,
Appendix R, is to ensure that one of the redundant trains necessary to
achieve and maintain hot shutdown conditions remains free of fire
damage in the event of a fire. Based on the existing fire barriers,
fire detectors, automatic and manual fire suppression equipment,
administrative controls, the fire hazard analysis, the Hemyc
configuration, and the absence of significant combustible loads and
ignition sources, special circumstances are present such that
application of this rule is not necessary. No new accident precursors
are created by allowing use of a fire barrier expected to provide less
than 1 hour of fire protection and the probability of postulated
accidents is not increased. Similarly, the consequences of postulated
accidents are not increased. Therefore, there is no undue risk (since
risk is probability multiplied by consequences) to public health and
safety.
Consistent With Common Defense and Security
The proposed exemption would allow use of a fire barrier expected
to provide less than 1 hour of fire protection based on the existing
fire barriers, fire detectors, automatic and manual fire suppression
equipment, administrative controls, the fire hazard analysis, the Hemyc
configuration, and the absence of significant combustible loads and
ignition sources. This change to the plant requirements for the
specific configuration in this fire zone has no relation to security
issues. Therefore, the common defense and security is not impacted by
this exemption.
4.0 Conclusion
Accordingly, the Commission has determined that, pursuant to 10 CFR
50.12(a), the exemption is authorized by law, will not present an undue
risk to the public health and safety, and is consistent with the common
defense and security. Specifically, special circumstances are present
in that the application of the regulation is not necessary to achieve
the underlying purpose of the rule. Therefore, the Commission hereby
grants ENO an exemption from the requirement of a 1-hour rated fire
barrier (fire wrap) in Section III.G.2.c of 10 CFR Part 50, Appendix R,
for the West Cable Tunnel at JAF provided that the proposed revisions
to the procedures for hot work in the vicinity of the Hemyc
configuration are implemented. The granting of this exemption is based
on the implementation of revised administrative controls for hot work
in the vicinity of the Hemyc configuration in FZ CT-1 (addressed in
Section 3.3 above), the existing or upgraded fire barrier protection
features in FZ CT-1, the maintenance of existing automatic detection
and suppression features in FZ CT-1, and the availability of manual
fire fighting and associated fire fighting equipment.
Pursuant to 10 CFR 51.32, the Commission has determined that the
granting of this exemption will not have a significant effect on the
quality of the human environment (71 FR 54100).
This exemption is effective upon issuance.
Dated at Rockville, Maryland, this 27th day of September 2006.
For the Nuclear Regulatory Commission.
Catherine Haney,
Director, Division of Operating Reactor Licensing, Office of Nuclear
Reactor Regulation.
[FR Doc. E6-16262 Filed 10-2-06; 8:45 am]
BILLING CODE 7590-01-P