[Federal Register Volume 64, Number 80 (Tuesday, April 27, 1999)]
[Notices]
[Pages 22655-22657]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-10489]


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NUCLEAR REGULATORY COMMISSION

[Docket No. 50-289]


GPU Nuclear, Inc. et al. (Three Mile Island Nuclear Generating 
Station, Unit 1); Exemption

I

    GPU Nuclear, Inc., et al. (GPUN or the licensee) is the holder of 
Facility Operating License No. DPR-50, which authorizes operation of 
the Three Mile Island Nuclear Generating Station, Unit 1 (TMI-1 or the 
facility) at power levels not to exceed 2568 megawatts thermal. The 
facility consists of one pressurized-water reactor located at the 
licensee's site in Dauphin County, Pennsylvania, and was licensed to 
operate on April 19, 1974. The license provides, among other things, 
that the licensee is subject to all rules, regulations, and orders of 
the Nuclear Regulatory Commission (the Commission) now or hereafter in 
effect.

II

    Appendix R to 10 CFR part 50 contains specific requirements 
regarding fire protection features of nuclear power plants operating 
prior to January 1, 1979. Subsection III.G.2.c of Appendix R specifies, 
in part, the enclosure of cable and equipment and associated non-
safety-related circuits of one redundant train in a fire barrier having 
a 1-hour rating. The underlying purpose of Subsection III.G.2.c of 
Appendix R is to provide reasonable assurance that one safe shutdown 
train and associated circuits used to achieve and maintain safe 
shutdown are free of fire damage. By letter dated December 31, 1996, as 
supplemented by letters dated September 8, 1997, December 30, 1997, May 
21, 1998, October 14, 1998, November 25, 1998, and December 23, 1998, 
the licensee requested an exemption from the requirements of section 
III.G.2.c of Appendix R to the extent that they require the enclosure 
of one train of redundant safe-shutdown circuits in 1-hour fire-rated 
barriers. The licensee is requesting this exemption in accordance with 
the provisions of 10 CFR 50.12.
    The licensee's request encompasses 10 fire zones/areas that have 
Thermo-Lag installed on electrical raceways for the original purpose of 
providing a 1-hour rated barrier separating redundant circuits located 
in the same fire area in accordance with section III.G.2.c of Appendix 
R. In its December 31, 1996, letter, the licensee provided information 
indicating that the Thermo-Lag envelopes in the zones/areas for which 
exemptions are requested, have fire endurance ratings of less than 1 
hour. The exemption was requested for fire zones/areas AB-FZ-3, AB-FZ-
4, AB-FZ-5, AB-FZ-7, CB-FA-1, FH-FZ-1, FH-FZ-2, FH-FZ-6, ISPH-FZ-1, and 
ISPH-FZ-2. In its submittal, the licensee states that modification of 
the identified fire barriers to achieve a 1-hour fire rating in 
accordance with American Society for Testing and Materials Standard E-
119 (ASTM E-119) would cost approximately $1.0 million, which 
represents a substantial expenditure for minimal safety enhancement.
    The staff holds to a defense-in-depth philosophy when determining 
adequate fire protection. In areas in which fire barriers are required 
to be rated at 1 hour, barriers that have actual fire endurance ratings 
of less than 1 hour are acceptable only if the fire area/zone also has 
automatic detection and fire suppression systems provided in accordance 
with applicable National Fire Protection Association (NFPA) standards 
and when the fire hazard to the Thermo-Lag-protected envelope is 
minimal. The combination of these features and conditions provides 
defense in depth.
    The fire areas/zones that are the subject of this exemption request 
do not currently meet the technical requirements of section III.G.2.c 
of Appendix R because the Thermo-Lag electrical raceway fire barrier 
envelopes for the fire zones discussed above are not rated at 1 hour in 
accordance with the rating requirements of NRC Generic Letter 86-10, 
Supplement 1. Section III.G.2.c of Appendix R could only be satisfied 
by protecting each envelope with a 1-hour fire-rated barrier. The fire 
zones reviewed do not have any Thermo-Lag envelopes rated at 1 hour or 
more; therefore, the criteria for granting an exemption, for the most 
part, are based on the availability of automatic detection and 
suppression systems and the fire hazards present in each fire zone.

III

    The staff has completed its evaluation of the licensee's request 
for an exemption. The licensee has administrative controls in place 
over transient combustibles and work in the plant in accordance with 10 
CFR part 50, Appendix R, section III.K, Items 1-8, as documented in an 
NRC safety evaluation dated June 4, 1984. These controls require total 
in situ plus allowable transient fire load in a fire area/zone (or 
cumulative load) to be half of what would challenge the lowest rated 
barrier in the zone based on equivalent fire severity. These limits are 
documented in licensee procedures that are referenced in and implement 
the licensee's Fire Protection Program under License Condition 2.c(4).
    On December 31, 1996, the licensee submitted an evaluation of all 
Thermo-Lag Fire barriers that are the subject of this exemption request 
in Topical Report #094, Revision 2, ``TMI 1 Evaluation of Thermo-Lag 
Fire Barriers,'' dated December 20, 1996. The licensee found that most 
of the barriers currently have a fire rating of less than 1 hour (when 
tested in accordance with the ASTM E-119). In each of the areas/zones 
that have automatic suppression and/or automatic detection features, 
the systems installed in the plant meet all applicable NFPA codes, 
specifically the criteria for a Class 1 detection system specified in 
NFPA 72D and NFPA 13 or NFPA 15 for suppression systems.
    Fire zones AB-FZ-4 and FH-FZ-1 contain both automatic suppression 
and detection features. Fires in these zones are postulated to be 
slowly developing cable fires, with possible ignition sources including 
cable overload or transient combustibles. If a fire were to occur in 
these fire zones, indication of the fire would be received in the 
control room, through the ionization smoke detection system, and either 
the automatic pre-action system (AB-FZ-4) or the wet pipe sprinkler 
system (FH-FZ-1) would initiate suppression if the fire continued to 
grow. If necessary, the fire brigade would be dispatched soon 
thereafter. The licensee estimates that the fire brigade will respond 
to these fire zones 15 minutes after receiving an alarm. Manual fire 
fighting equipment (hand-held fire extinguishers and hose stations) is 
available in or adjacent to these fire zones.
    Fire area CB-FA-1 contains both automatic suppression and detection 
capability. A fire in this area is postulated to be a slowly developing 
cable fire, with possible ignition sources being overload or transient 
combustibles. Exposure of the protected envelope to fire is possible 
through ignition of cable insulation. There is also an acetylene gas 
line running above the suspended ceiling from an external tank. The 
licensee committed in its October 14, 1998, and December 23, 1998, 
letters to install detectors for

[[Page 22656]]

combustible gas in this area to provide prompt detection and 
notification of an acetylene leak, so that the leak could be promptly 
isolated at the source prior to reaching the lower explosive threshold 
for acetylene gas. If a fire were to occur in this fire area, 
indication of the fire would be received in the control room, through 
the ionization smoke detection system which is above the suspended 
ceiling. An automatic wet-pipe sprinkler system which is below the 
suspended ceiling would actuate to suppress the fire should it continue 
to develop. If necessary, the fire brigade would be dispatched soon 
thereafter, and response has been estimated by the licensee to be 15 
minutes. A hand-held dry chemical extinguisher is also available 
adjacent to this fire area.
    Fire zone FH-FZ-6 is provided with automatic detection and will be 
provided with automatic suppression. The licensee committed to install 
an automatic wet-pipe sprinkler suppression system in this fire zone in 
its letter dated December 23, 1998. A fire in this zone is postulated 
to be a slowly developing cable fire, with possible ignition sources 
being transient combustibles. If a fire were to occur in this fire 
zone, indication of the fire would be received in the control room by 
the ionization smoke detection system or through the actuation of the 
wet-pipe sprinkler system to be installed. If necessary, the fire 
brigade would be dispatched soon thereafter, and the licensee estimates 
a brigade response would occur within 15 minutes. Manual fire 
suppression capability (hose stations and dry chemical extinguisher) is 
available in or adjacent to this fire zone.
    Fire zone ISPH-FZ-1 contains both automatic detection and 
suppression features. A fire in this zone is postulated to be a slowly 
developing cable fire, with electrical switchgear as a possible 
ignition source. If a fire were to occur in this zone, indication of 
the fire would be received in the control room by the ionization smoke 
detector system. A zone-wide automatic wet-pipe sprinkler system is 
available to suppress the fire, should it develop, and portable 
extinguishers (carbon dioxide and dry chemical) are available within 
the fire zone. The fire brigade would be dispatched, if necessary, and 
the licensee estimates a brigade response time of 25 minutes. A 
portable extinguisher and yard hydrant are located outside the fire 
area and are available to fight fires in this fire zone. Protected 
envelopes consisting of cables and conduits passing through this fire 
zone are fire rated at 39 and 50 minutes respectively, and pass within 
the vicinity of in-situ combustibles in only limited instances.
    Fire zone ISPH-FZ-2 contains both automatic detection and 
suppression features. A fire in this zone is postulated to be a slowly 
developing cable fire, with electrical switchgear as a possible 
ignition source. If a fire were to occur in this zone, indication of 
the fire would be received in the control room by the ionization smoke 
detector system. A zone-wide automatic wet-pipe sprinkler system is 
available to suppress the fire, should it develop, and a portable 
extinguisher (carbon dioxide) is available within the fire zone. The 
fire brigade would be dispatched, if necessary, and the licensee 
estimates a brigade response time of 25 minutes. A portable 
extinguisher and yard hydrant are located outside the fire area and are 
available to fight fires in this fire zone. Protected envelopes 
consisting of cables and conduits passing through this fire zone are 
fire rated at 39 and 50 minutes, respectively, and pass within the 
vicinity of in-situ combustibles in only limited instances.
    The staff is relying on the licensee's commitments made in its 
October 14, 1998, and December 23, 1998, letters for approval of the 
exemptions for fire area CB-FA-1 and fire zone FH-FZ-6. Therefore, 
approval of an exemption for that fire area and zone is contingent upon 
the licensee completing the modifications described in those 
submittals. The staff believes that reasonable assurance exists that an 
adequate level of fire safety has been provided through the 
availability of automatic suppression and detection in these fire 
zones/areas to ensure that one division of safe-shutdown components 
necessary to achieve safe shutdown will remain free of fire damage. 
Therefore, the underlying purpose of the rule is satisfied and this 
request for exemption with respect to the foregoing fire areas/zones 
from the requirements of 10 CFR part 50, Appendix R, section III.G.2.c 
meets the special circumstances delineated in 10 CFR 50.12(a)(2)(ii) in 
that the application of the regulation in these particular 
circumstances is not necessary to achieve the underlying purpose of the 
rule. While the installed Thermo-Lag barriers in the fire zones 
demonstrate less than a 1-hour fire endurance rating, they do provide 
measured resistance to fire. The areas in which the Thermo-Lag 
envelopes are located have a low combustible loading in the area of the 
protected envelopes, have available manual suppression capability, and 
are equipped with automatic suppression and detection features; the 
combination of these features and circumstances reflect a level of 
safety that meets the underlying purpose of the rule. Therefore, the 
staff believes that the exemption should be granted for fire zones/
areas AB-FZ-4, FH-FZ-1, CB-FA-1, FH-FZ-6, ISPH-FZ-1, and ISPH-FZ-2.
    The staff does not believe the same assurance has been provided for 
fire zones AB-FZ-3, AB-FZ-5, AB-FZ-7, and FH-FZ-2. Fire zones AB-FZ-3, 
AB-FZ-5, and AB-FZ-7, have automatic detection but not suppression. 
Fire zone FH-FZ-2 has automatic suppression but not detection.
    The licensee has failed to provide reasonable assurance that one 
division of safe-shutdown components necessary to achieve safe shutdown 
will remain free of fire damage in the four zones immediately discussed 
above. Accordingly, as discussed above and in the staff's Safety 
Evaluation dated April 20, 1999, the staff has concluded that the 
licensee's request for an exemption from the technical requirements of 
section III.G.2.c of Appendix R should be denied for fire zones AB-FZ-
3, AB-FZ-5, AB-FZ-7, and FH-FZ-2.

IV

    Pursuant to 10 CFR 50.12(a)(2), the Commission will not consider 
granting an exemption from the requirements of a regulation unless 
special circumstances are present. Subsection (ii) of 10 CFR 
50.12(a)(2) includes as special circumstances situations where 
application of the subject regulation would not serve the underlying 
purpose of the rule or is not necessary to achieve the underlying 
purpose of the rule.
    The underlying purpose of section III.G of Appendix R is to provide 
reasonable assurance that one safe shutdown train and associated 
circuits used to achieve and maintain safe shutdown are free of fire 
damage. As stated above, the staff has determined that the underlying 
purpose of the rule has been satisfied with respect to fire zones AB-
FZ-4, FH-FZ-1, CB-FA-1, FH-FZ-6, ISPH-FZ-1 and ISPH-F2-2. Accordingly, 
the Commission has determined that, pursuant to 10 CFR 50.12(a)(2)(ii) 
special circumstances are present in connection with these fire zone/
areas.
    The Commission has also determined that, pursuant to 10 CFR 50.12, 
the exemption requested by the licensee for fire zones/areas AB-FZ-4, 
FH-FZ-1, CB-FA-1, FH-FZ-6, ISPH-FZ-1, and ISPH-FZ-2 is authorized by 
law, will not present an undue risk to public health and safety, and is 
consistent with the common defense and security.
    Therefore, the Commission hereby grants GPU Nuclear, Inc., an 
exemption

[[Page 22657]]

from the technical requirements of section III.G.2.c of Appendix R to 
10 CFR part 50, to the extent that it requires the enclosure of certain 
redundant safe-shutdown circuits in 1-hour fire-rated barriers, for 
fire zones/areas AB-FZ-4, FH-FZ-1, CB-FA-1, FH-FZ-6, ISPH-FZ-1, and 
ISPH-FZ-2 at TMI-1. The exemption for fire area CB-FA-1 and fire zone 
FH-FZ-6 is contingent upon the licensee completing the commitments 
identified in its letters of October 14, 1998, and December 23, 1998, 
for that fire area and zone. The request for exemption for fire zones 
AB-FZ-3, AB-FZ-5, AB-FZ-7, and FH-FZ-2 is denied.
    Pursuant to 10 CFR 51.32, the Commission has determined that the 
issuance of this exemption will have no significant impact on the 
quality of the human environment (64 FR 19205).
    This exemption is effective upon issuance.

    Dated at Rockville, Maryland, this 20th day of April 1999.

    For the Nuclear Regulatory Commission.
John A. Zwolinski,
Director, Division of Licensing Project Management, Office of Nuclear 
Reactor Regulation.
[FR Doc. 99-10489 Filed 4-26-99; 8:45 am]
BILLING CODE 7590-01-P