Tennessee Valley Authority Browns Ferry Nuclear Plant, Units 1, 2, and 3 Docket Nos. 50-259, 50-260, and 50-296 Exemption, 16832-16835 [07-1696]

Download as PDF 16832 Federal Register / Vol. 72, No. 65 / Thursday, April 5, 2007 / Notices jlentini on PROD1PC65 with NOTICES Agency will summarize the comments submitted in response to this notice, and will include this summary in its request to OMB. Type of Review: Extension of a currently approved collection. Title: Asbestos in General Industry (29 CFR 1910.1001). OMB Number: 1218–0133. Affected Public: Business or other forprofit. Number of Respondents: 243. Frequency: Annually; semi-annually. Total Responses: 65,048. Average Time per Response: Varies from 5 minutes to maintain records to 1.5 hours for employees to receive training or medical evaluations. Estimated Total Burden Hours: 23,849. Estimated Cost (Operation and Maintenance): $1,625,143. IV. Public Participation—Submission of Comments on This Notice and Internet Access to Comments and Submissions You may submit comments in response to this document as follows: (1) Electronically at http:// www.regulations.gov, which is the Federal eRulemaking Portal; (2) by facsimile; or (3) by hard copy. All comments, attachments, and other material must identify the Agency name and the OSHA docket number for this ICR (OSHA Docket No. OSHA–2007– 0026). You may supplement electronic submissions by uploading document files electronically. If you wish to mail additional materials in reference to an electronic or facsimile submission, you must submit them to the OSHA Docket Office (see the section of this notice titled ‘‘ADDRESSES’’). The additional materials must clearly identify your electronic comments by your full name, date, and docket number so the Agency can attach them to your comments. Because of security procedures, the use of regular mail may cause a significant delay in the receipt of comments. For information about security procedures concerning the delivery of materials by hand, express delivery, messenger, or courier service, please contact the OSHA Docket Office at (202) 693–2350 (TTY (877) 889– 5627). Comments and submissions are posted without change at http:// www.regulations.gov. Therefore, OSHA cautions commenters about submitting personal information such as social security numbers and date of birth. Although all submissions are listed in the http://www.regulations.gov index, some information (e.g., copyrighted material) is not publicly available to read or download through this website. VerDate Aug<31>2005 17:37 Apr 04, 2007 Jkt 211001 All submissions, including copyrighted material, are available for inspection and copying at the OSHA Docket Office. Information on using the http:// www.regulations.gov Web site to submit comments and access the docket is available at the website’s ‘‘User Tips’’ link. Contact the OSHA Docket Office for information about materials not available through the website, and for assistance in using the Internet to locate docket submissions. V. Authority and Signature Edwin G. Foulke, Jr., Assistant Secretary of Labor for Occupational Safety and Health, directed the preparation of this notice. The authority for this notice is the Paperwork Reduction Act of 1995 (44 U.S.C. 3506 et seq.) and Secretary of Labor’s Order No. 5–2002 (67 FR 65008). Signed at Washington, DC on April 2, 2007. Edwin G. Foulke, Jr., Assistant Secretary of Labor. [FR Doc. E7–6367 Filed 4–4–07; 8:45 am] BILLING CODE 4510–26–P NUCLEAR REGULATORY COMMISSION Tennessee Valley Authority Browns Ferry Nuclear Plant, Units 1, 2, and 3 Docket Nos. 50–259, 50–260, and 50– 296 Exemption 1.0 Background The Tennessee Valley Authority (TVA, the licensee) is the holder of Facility Operating Licenses DPR–33, DPR–52, and DPR–68, which authorize operation of the Browns Ferry Nuclear Plant, Units 1, 2 and 3. The license provides, among other things, that the facility is subject to all rules, regulations, and orders of the Nuclear Regulatory Commission (NRC, the Commission) now or hereafter in effect. The facility consists of three boilingwater reactors located in Limestone County in Alabama. 2.0 Request/Action On November 19, 1980, the Commission published a new Appendix R to Title 10 to the Code of Federal Regulations (10 CFR) Part 50 regarding fire protection features of nuclear power plants (45 FR 76602). Section 50.48(a) requires that each operating nuclear power plant have a fire protection plan which satisfies General Design Criterion (GDC) 3, ‘‘Fire protection,’’ in Appendix A, ‘‘General Design Criteria for Nuclear Power Plants,’’ to 10 CFR Part 50. The approved fire protection plan is the plan PO 00000 Frm 00071 Fmt 4703 Sfmt 4703 required to satisfy 10 CFR 50.48(a). Specific fire protection features deemed necessary to ensure this capability are delineated in Appendix R to 10 CFR Part 50. Section III of Appendix R contains 15 subsections, lettered A through O, each of which specifies the requirements for a particular aspect of fire protection features at nuclear power plants. The Browns Ferry units are required to comply with the provisions of Sections III.G and III.J and III.O. Section III.G.2 of Appendix R to 10 CFR Part 50 requires that where cables or equipment of redundant trains of systems necessary to achieve and maintain hot shutdown conditions are located within the same fire area outside of primary containment, one of the following means of ensuring that one of the redundant trains is free of fire damage shall be provided: a. Separation of cables and equipment and associated non-safety circuits of redundant trains by a fire barrier having a 3-hour rating. Structural steel forming a part of or supporting such fire barriers shall be protected to provide fire resistance equivalent to that required of the barrier; b. Separation of cables and equipment and associated non-safety circuits of redundant trains by a horizontal distance of more than 20 feet with no intervening combustible or fire hazards. In addition, fire detectors and an automatic fire suppression system shall be installed in the fire area; or c. Enclosure of cable and equipment and associated non-safety circuits of one redundant train in a fire barrier having a 1-hour rating. In addition, fire detectors and an automatic fire suppression system shall be installed in the fire area; By letter dated October 26, 2006, as supplemented by a letter dated January 11, 2007, the licensee requested a revision to an exemption from 10 CFR 50 Appendix R, III.G.2. For the items specified in this exemption request, the licensee has selected III.G.2.b as the option for compliance with Appendix R, Section II.G.2. The exemption involves allowing intervening combustible materials, for example, fire hazards (480V reactor building (RB) vent boards 1B, 2B, and 3B; small panels in Units 1, 2, and 3, and 1-hour rated Thermo-Lag 330–1 electrical raceway fire barrier (ERFB) material), in the specified 20 feet of separation protected with fire detection and automatic water-based fire suppression between redundant safe-shutdown trains. The redundant trains are separated by a horizontal distance of 20 feet with intervening combustibles in certain fire zones in the Units 1, 2, and 3 RBs. E:\FR\FM\05APN1.SGM 05APN1 Federal Register / Vol. 72, No. 65 / Thursday, April 5, 2007 / Notices Exemptions are requested from the requirements to provide 20 feet of separation, free of intervening • • • • • • • • • • • • Unit Unit Unit Unit Unit Unit Unit Unit Unit Unit Unit Unit 1 1 1 1 1 1 2 2 2 2 3 3 Fire Fire Fire Fire Fire Fire Fire Fire Fire Fire Fire Fire Zone Zone Zone Zone Zone Zone Zone Zone Zone Zone Zone Zone 1–1/1–2 1–1/1–2 1–1/1–2 1–3/1–4 1–3/1–4 1–3/1–4 2–1/2–4 2–1/2–2 2–3/2–4 2–3/2–4 3–1/3–2 3–1/3–2 ................. ................. ................. ................. ................. ................. ................. ................. ................. ................. ................. ................. jlentini on PROD1PC65 with NOTICES • Unit 3 Fire Zone 3–1/3–2 ................. combustibles. The following is a list of those fire zone locations and intervening combustibles/fire hazards 565′ 565′ 565′ 593′ 593′ 593′ 565′ 565′ 593′ 593′ 565′ 565′ 1 The Units 2 and 3 configuration are very similar and the results of this analysis are applicable to 480V (RB) vent board 2B and 480V (RB) vent board 3B. 17:37 Apr 04, 2007 Jkt 211001 ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... ....... 565′ Elevation ....... To justify inclusion of intervening combustibles in RB fire areas, the licensee performed fire modeling to assess potential hazards using methodology from NUREG–1805, ‘‘Fire Dynamics Tools (FDTs) Quantitative Fire Hazard Analysis Methods for the U.S. Nuclear Regulatory Commission Fire Protection Inspection Program,’’ December 2004. Enclosure 2 of the exemption request discussed the firerisk analysis for the Units 1, 2, and 3 RBs. TVA provided an assessment utilizing fire modeling to evaluate the fire hazards due to intervening combustibles between redundant cable trains in the RBs. In this fire modeling analysis, the licensee modeled fire in Unit 1 RB Elevation 565′ in the 20-foot zone of separation between fire zones 1–1 and 1–2.1 Specifically, 480V (RB) vent boards 1B, 2B, and 3B are located within the 20-foot zone of separation. The fire model uses a series of empirical correlations from NUREG–1805 to show the largest fire from a vertical low voltage electrical cabinet should not produce enough radiant energy to ignite the closest redundant cable trays or intervening combustibles within the redundant trains. The analysis is used to determine the extent of the potential fire damage associated with a realistic worst case fire scenario between Unit 1 RB fire zones 1–1 and 1–2 and the anticipated failure of cables or equipment of redundant trains of systems required for safe-shutdown. A fire scenario was postulated for the Unit 1 RB, that is, fire started in a vertical electrical cabinet (480V RB vent board 1B). This cabinet has 12 vertical sections with no vent openings. The penetrations in the cabinet consist of sealed conduits on top VerDate Aug<31>2005 Elevation Elevation Elevation Elevation Elevation Elevation Elevation Elevation Elevation Elevation Elevation Elevation 2 HRR is the rate at which heat energy is generated by burning. The HRR of a fuel is related to its chemistry, physical form, and availability of oxidant. When an object burns, it releases a certain amount of energy per unit of time. For most materials, the HRR of a fuel changes with time, in relation to its chemistry, physical form, and availability of oxidant (air), and is ordinarily expressed as kW (kJ/sec) or Btu/sec and denoted by ˙ Q (1,000 kW = 1 MW or 1 BTU/sec = 1.055 kW). Frm 00072 present within a 20-foot spatial separation zone for redundant safeshutdown trains: 480V (RB) Vent Board 1B. 1-LPLN–925–338 & 338A Process Radiation Monitor and Relay Panel. Thermo-Lag on Conduits ES2625-II and ES2673–II. Thermo-Lag on Conduits PP459-IA, PP460-IA, and ES125-I. 1-LPLN–925–0281A Fire Detection Panel. 1-LPLN–925–0315 Heat Detection Panel. 480V (RB) Vent Board 2B. 2-PWR–276–0007 480V Power Distribution Panel. 25–281A Fire Detection Panel. 25–316 Cable Tray Fire Detection Control. 480 V (RB) Vent Board 3B. 1-LPLN–925–336 & 336A Raw Cooling Water Effluent Radiation Monitor and Relay Panel. 1-LPLN–925–337 & 337A Process Radiation Monitor and Relay Panel. of the cabinet. The fire started from nonqualified Institute of Electronics and Electrical Engineering Standard (IEEE)– 383 cables within the cabinet and was assumed to be limited to one cable bundle. The heat release rate (HRR) 2 used to calculate heat fluxes to the targets (cable trays located at radial distance of approximately 7 feet [17 feet above floor], conduits located at the bottom of the duct approximately 9 feet above the top of the cabinet, and Thermo-Lag 330–1 wrapped conduit located approximately 7 feet from the edge of the cabinet) was based on Table E–4 in Appendix E of NUREG/CR–6850 (EPRI [Electric Power Research Institute] TR–1019181), ‘‘EPRI/NRC–RES Fire PRA [Probabilistic Risk Analysis] Methodology for Nuclear Power Facilities,’’ November 2005. In order to evaluate the licensee’s conclusion that a cabinet fire would not result in fire damage adversely affecting the safe-shutdown capability in Units 1, 2, and 3 RB located within the 20-foot separation area, the NRC staff identified areas in which additional information was necessary to complete its evaluation. The NRC staff had discussions with the licensee on November 20, 2006, concerning use of the HRR of a single bundle cable (vs. multiple bundles) fire from NUREG/CR– 6850 in fire modeling. Specifically, the NRC staff requested TVA to justify how the single bundle cable HRR assumption bounds the worst case cabinet fire scenario. On January 11, 2007 (ADAMS Accession Number ML070160050), TVA PO 00000 16833 Fmt 4703 Sfmt 4703 provided a revised fire model to address the NRC concerns. In the revised fire modeling analysis, the HRR for multiple-cable bundles was assumed due to multiple conduit entries in each section of the low voltage vertical cabinet. The HRR associated with multiple-cable bundles for a vertical cabinet with non-qualified IEEE–383 cables was based on Table E– 5 in Appendix E of NUREG/CR–6850. The critical incident radiative heat flux 3 for ignition is calculated from the cabinet fire scenario to see if ignition of the redundant cables and adjacent surrounding targets (intervening combustibles) is possible. The critical incident radiative heat flux from the maximum fire HRR, that is, 816 Kilowatt (kW), was estimated at 4.28 kW/m2. The licensee determined that the maximum radiant heat flux is not sufficient to ignite non-qualified IEEE– 383 cable or Thermo-Lag 330–1 wrapped on conduits or safety-related cables or equipment of redundant trains of systems for safe-shutdown, nor to adversely impact any surrounding equipment. The targets require a large amount of radiative heat to ignite. The measured critical heat flux level for representative non-qualified IEEE–383 or thermoplastic cable samples typically is in the range of 6 kW/m2 (NUREG/CR– 6850, Appendix H, Table H–1). The measured critical heat flux for ignition for Thermo-Lag 330–1 ERFB material is 25 kW/m2 based on American Society of Testing and Materials (ASTM) E1321, ‘‘Standard Test Method for Determining Material Ignition and Flame Spread 3 The incident heat flux (the rate of heat transfer per unit area that is normal to the direction of heat flow—it is a total of heat transmitted by radiation, conduction, and convection) required to raise the surface of a target to a critical temperature is termed the critical heat flux. Below this heat flux an object will typically not ignite while above this heat flux the time to ignition will decrease with the increasing heat flux. E:\FR\FM\05APN1.SGM 05APN1 jlentini on PROD1PC65 with NOTICES 16834 Federal Register / Vol. 72, No. 65 / Thursday, April 5, 2007 / Notices Properties’’ (TVA October 26, 2006 (ADAMS ML063040310)). Based on the above evaluation, the NRC staff concludes that the ability of Units 1, 2, and 3 to achieve and maintain safe-shutdown conditions in accordance with the requirements of Section III.G.2.b to Appendix R to 10 CFR 50 is not adversely affected by the inclusion of intervening combustibles or fire hazards in certain fire zones within Units 1, 2, and 3 RBs for the following reasons: —The fire modeling performed by the licensee provides reasonable assurance that redundant safeshutdown trains will be maintained free of fire damage. This is because the estimated heat flux from the maximum exposure fire is less than the critical heat flux for ignition for non-qualified IEEE–383 cable or Thermo-Lag 330–1 ERFB material. —In the event of a postulated fire in the Units 1, 2, and 3 RBs, all units can safely shut down using the alternate shutdown panel located outside each RB. The Browns Ferry Nuclear Plant Appendix R alternate shutdown strategy is described in the approved fire protection plan. —A significant fire is unlikely due to control of transient combustibles near the redundant trains. RB volume and height would dissipate heat from a cabinet fire and not threaten redundant trains. Smoke detectors and portable extinguishers were installed for quick fire detection and suppression. All electrical cabinets in the area of concern are enclosed with no ventilation openings and the bottom of the cable tray stacks have non-combustible covers. —A fire originating in a low voltage cabinet exposing intervening combustibles/targets (cable trays located at radial distance of approximately 7 feet, conduits located at the bottom of the duct approximately 9 feet above the top of the cabinet (17 feet above floor), and Thermo-Lag 330–1 wrapped conduit located approximately 7 feet from the edge of the cabinet) would be slow to develop. Based on the fire detection arrangement in the Units 1, 2, and 3 RBs, detection of this type of fire would occur well before the fire had time to develop into a fully developed cable tray fire scenario. —The NRC staff reviewed the physical configuration of the Units 1, 2, and 3 RBs, the associated fire hazards (intervening combustibles) and fire protection features, and fire response procedures. This review found that a fire that initiated in one of the VerDate Aug<31>2005 17:37 Apr 04, 2007 Jkt 211001 cabinets would likely be detected in its incipient stage, and fire-fighting activities initiated (including actuation of the automatic waterbased fire suppression system) before the fire becomes fully developed, thereby limiting its potential to spread. The NRC staff, therefore, finds the licensee’s proposed exemption to permit intervening combustibles in the 20-foot separation zone for certain specified fire areas in the Units 1, 2, and 3 RBs acceptable. The licensee indicated that all fire zones discussed previously are protected with fire detection and automatic pre-action sprinkler systems, manual fire extinguishers, and hose stations. If a fire were to occur in any of these locations it would be detected before significant flame propagation or increased temperature, radiative heat flux, and damaging smoke layering occurred. The fire brigade would then extinguish the fire using hose stations and manual fire fighting equipment. If rapid fire propagation occurred before the arrival of the fire brigade, one would expect the automatic pre-action sprinkler system to actuate and limit fire spread. Pending actuation of automatic pre-action sprinkler system, the physical separation of redundant trains is sufficient to provide reasonable assurance that one safe-shutdown train would remain free of fire damage. Therefore, the NRC staff concludes that the existing level of fire protection for the redundant safe-shutdown trains is an acceptable deviation from Section III.G.2 of Appendix R to 10 CFR Part 50. 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. These include the special circumstances that the underlying purpose of the rule is satisfied by the requested revision to the exemption, since the existing fire protection features and analyses demonstrate that the quantity of intervening combustibles permitted in the 20-foot separation zone does not affect the ability of the existing fire protection features to provide an equivalent level of protection as required by 10 CFR 50, Appendix R, Section III.G. PO 00000 Frm 00073 Fmt 4703 Sfmt 4703 Authorized by Law This exemption revision allows the existence of the specified intervening combustibles in the 20-foot separation zone identified previously. As stated above, 10 CFR 50.12 allows the NRC to grant exemptions from the requirements of 10 CFR 50.48 and Appendix R to 10 CFR 50. The NRC staff has determined that granting of the licensee’s proposed exemption will not result in a violation of 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 10 CFR 50.48 is to limit fire damage to structures, systems, and components (SSCs) important to safety so that the capability to shut down the plant safely is ensured. Compliance with the applicable provisions of Appendix R to Part 50 ensures that one train of cables and equipment necessary to achieve and maintain safe-shutdown are maintained free of fire damage. Based on the above, no new accident precursors are created by allowing the specified intervening combustibles into the 20-foot separation zone identified previously, thus, the probability of postulated accidents is not increased. Also, based on the above, the consequences of postulated accidents are not increased. Therefore, there is no undue risk to public health and safety. Consistent With Common Defense and Security The proposed exemption revision would allow the specified intervening combustibles into the 20-foot separation zone identified previously. This revision to the fire protection plan and existing exemptions has no relation to security issues. Therefore, the common defense and security are not impacted by this exemption. Special Circumstances In accordance with 10 CFR 50.12(a)(2), special circumstances are present whenever application of the regulation in the particular circumstances is not necessary to achieve the underlying purpose of the rule. The underlying purpose of 10 CFR 50.48 is to limit fire damage to SSCs important to safety so that the capability to shut down the plant safely is ensured. Compliance with the applicable provisions of Appendix R to Part 50 ensures that one train of cables and equipment necessary to achieve and maintain safe-shutdown are maintained free of fire damage. As the existence of E:\FR\FM\05APN1.SGM 05APN1 Federal Register / Vol. 72, No. 65 / Thursday, April 5, 2007 / Notices the intervening combustibles should not affect the capability of the installed suppression and detection system to detect and mitigate a fire, the underlying purpose of 10 CFR 50.48 and Appendix R is achieved. Therefore, the special circumstances required by 10 CFR 50.12(a)(2) for the granting of an exemption from 10 CFR 50.48 and Appendix R to 10 CFR 50 exist. 4.0 Conclusion Accordingly, the Commission has determined that, pursuant to 10 CFR 50.12, the revision to 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. Also, special circumstances are present. Therefore, the Commission hereby grants the TVA a revision to the exemption from the requirements of Section III.G.2 of Appendix R to 10 CFR 50 for the Browns Ferry Nuclear Plant, Units 1, 2 and 3. 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 (22 FR 9036). This exemption is effective upon issuance. Dated at Rockville, Maryland, this 29th day of March 2007. For the Nuclear Regulatory Commission. Catherine Haney, Director, Division of Operating Reactor Licensing, Office of Nuclear Reactor Regulation. [FR Doc. 07–1696 Filed 4–4–07; 8:45 am] BILLING CODE 7590–01–P UNITED STATES POSTAL SERVICE BOARD OF GOVERNORS Sunshine Act Meeting; Notification of Item Added to Meeting Agenda DATE OF MEETING: STATUS: March 28, 2007. Closed. 72 FR 14312, March 27, 2007. ADDITION: Proposed Filing with the Postal Regulatory Commission for an Extension of the Market Test for Repositionable Notes. At its closed meeting on March 28, 2007, the Board of Governors of the United States Postal Service voted unanimously to add this item to the agenda of its closed meeting and that no earlier announcement was possible. The General Counsel of the United States Postal Service certified that in her opinion discussion of this item could be properly closed to public observation. jlentini on PROD1PC65 with NOTICES PREVIOUS ANNOUNCEMENT: VerDate Aug<31>2005 17:37 Apr 04, 2007 Jkt 211001 CONTACT PERSON FOR MORE INFORMATION: Wendy A. Hocking, Secretary of the Board, U.S. Postal Service, 475 L’Enfant Plaza, SW., Washington, DC 20260– 1000. Wendy A. Hocking, Secretary. [FR Doc. 07–1717 Filed 4–3–07; 3:13 pm] BILLING CODE 7710–12–M SECURITIES AND EXCHANGE COMMISSION [Release No. IC–27771] Notice of Applications for Deregistration Under Section 8(f) of the Investment Company Act of 1940 March 30, 2007. The following is a notice of applications for deregistration under section 8(f) of the Investment Company Act of 1940 for the month of March 2007. A copy of each application may be obtained for a fee at the SEC’s Public Reference Branch (tel. 202–551–5850). An order granting each application will be issued unless the SEC orders a hearing. Interested persons may request a hearing on any application by writing to the SEC’s Secretary at the address below and serving the relevant applicant with a copy of the request, personally or by mail. Hearing requests should be received by the SEC by 5:30 p.m. on April 25, 2007, and should be accompanied by proof of service on the applicant, in the form of an affidavit or, for lawyers, a certificate of service. Hearing requests should state the nature of the writer’s interest, the reason for the request, and the issues contested. Persons who wish to be notified of a hearing may request notification by writing to the Secretary, U.S. Securities and Exchange Commission, 100 F Street, NE., Washington, DC 20549– 1090. For Further Information Contact: Diane L. Titus at (202) 551–6810, SEC, Division of Investment Management, Office of Investment Company Regulation, 100 F Street, NE., Washington, DC 20549–4041. The Preferred Group of Mutual Funds [File No. 811–6602] Summary: Applicant seeks an order declaring that it has ceased to be an investment company. On June 19, 2006, each of applicant’s series transferred its assets to the following corresponding funds, based on net asset value: T. Rowe Price Value Fund, Inc., T. Rowe Price Growth Stock Fund, Inc., T. Rowe Price Mid-Cap Growth Fund, Inc., T. Rowe Price New Horizons Fund, Inc., T. Rowe PO 00000 Frm 00074 Fmt 4703 Sfmt 4703 16835 Price Capital Appreciation Fund, T. Rowe Price International Funds, Inc., T. Rowe Price Short-Term Bond Fund, Inc., T. Rowe Price New Income Fund, Inc. and T. Rowe Price Summit Funds, Inc. Expenses of approximately $490,000 incurred in connection with the reorganization were paid by Caterpillar Investment Management Ltd., applicant’s investment adviser. Filing Dates: The application was filed on July 20, 2006, and amended on October 30, 2006, January 12, 2007 and March 23, 2007. Applicant’s Address: 411 Hamilton Blvd., Suite 1200, Peroria, IL 61602. AIM Floating Rate Fund [File No. 811– 9797] Summary: Applicant, a closed-end investment company, seeks an order declaring that it has ceased to be an investment company. On April 13, 2006, applicant transferred its assets to AIM Counselor Series Trust, based on net asset value. Expenses of $238,190 incurred in connection with the reorganization were paid by A I M Advisors, Inc., applicant’s investment adviser. Filing Date: The application was filed on February 23, 2007. Applicant’s Address: 11 Greenway Plaza, Suite 100, Houston, TX 77046– 1173. Pioneer Balanced Fund [File No. 811– 1605] Pioneer America Income Trust [File No. 811–5516] Summary: Each applicant seeks an order declaring that it has ceased to be an investment company. On November 10, 2006, each applicant transferred its assets to corresponding series of Pioneer Series Trust IV, based on net asset values. Expenses of $80,698 and $81,259, respectively, incurred in connection with the reorganizations were paid by each applicant, the acquiring fund, and Pioneer Investment Management, Inc., investment adviser to both applicants and the acquiring fund. Filing Date: The applications were filed on March 5, 2007. Applicants’ Address: 60 State St., Boston, MA 02109. Pioneer Europe Select Fund [File No. 811–10111] Summary: Applicant seeks an order declaring that it has ceased to be an investment company. On June 24, 2005, applicant transferred its assets to Pioneer Europe Select Equity Fund, based on net asset value. Expenses of $23,688 incurred in connection with the reorganization were paid by Pioneer Investment Management, Inc., E:\FR\FM\05APN1.SGM 05APN1

Agencies

[Federal Register Volume 72, Number 65 (Thursday, April 5, 2007)]
[Notices]
[Pages 16832-16835]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 07-1696]


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NUCLEAR REGULATORY COMMISSION


Tennessee Valley Authority Browns Ferry Nuclear Plant, Units 1, 
2, and 3 Docket Nos. 50-259, 50-260, and 50-296 Exemption

1.0 Background

    The Tennessee Valley Authority (TVA, the licensee) is the holder of 
Facility Operating Licenses DPR-33, DPR-52, and DPR-68, which authorize 
operation of the Browns Ferry Nuclear Plant, Units 1, 2 and 3. The 
license provides, among other things, that the facility is subject to 
all rules, regulations, and orders of the Nuclear Regulatory Commission 
(NRC, the Commission) now or hereafter in effect.
    The facility consists of three boiling-water reactors located in 
Limestone County in Alabama.

2.0 Request/Action

    On November 19, 1980, the Commission published a new Appendix R to 
Title 10 to the Code of Federal Regulations (10 CFR) Part 50 regarding 
fire protection features of nuclear power plants (45 FR 76602). Section 
50.48(a) requires that each operating nuclear power plant have a fire 
protection plan which satisfies General Design Criterion (GDC) 3, 
``Fire protection,'' in Appendix A, ``General Design Criteria for 
Nuclear Power Plants,'' to 10 CFR Part 50. The approved fire protection 
plan is the plan required to satisfy 10 CFR 50.48(a). Specific fire 
protection features deemed necessary to ensure this capability are 
delineated in Appendix R to 10 CFR Part 50. Section III of Appendix R 
contains 15 subsections, lettered A through O, each of which specifies 
the requirements for a particular aspect of fire protection features at 
nuclear power plants. The Browns Ferry units are required to comply 
with the provisions of Sections III.G and III.J and III.O. Section 
III.G.2 of Appendix R to 10 CFR Part 50 requires that where cables or 
equipment of redundant trains of systems necessary to achieve and 
maintain hot shutdown conditions are located within the same fire area 
outside of primary containment, one of the following means of ensuring 
that one of the redundant trains is free of fire damage shall be 
provided:
    a. Separation of cables and equipment and associated non-safety 
circuits of redundant trains by a fire barrier having a 3-hour rating. 
Structural steel forming a part of or supporting such fire barriers 
shall be protected to provide fire resistance equivalent to that 
required of the barrier;
    b. Separation of cables and equipment and associated non-safety 
circuits of redundant trains by a horizontal distance of more than 20 
feet with no intervening combustible or fire hazards. In addition, fire 
detectors and an automatic fire suppression system shall be installed 
in the fire area; or
    c. Enclosure of cable and equipment and associated non-safety 
circuits of one redundant train in a fire barrier having a 1-hour 
rating. In addition, fire detectors and an automatic fire suppression 
system shall be installed in the fire area;
    By letter dated October 26, 2006, as supplemented by a letter dated 
January 11, 2007, the licensee requested a revision to an exemption 
from 10 CFR 50 Appendix R, III.G.2. For the items specified in this 
exemption request, the licensee has selected III.G.2.b as the option 
for compliance with Appendix R, Section II.G.2. The exemption involves 
allowing intervening combustible materials, for example, fire hazards 
(480V reactor building (RB) vent boards 1B, 2B, and 3B; small panels in 
Units 1, 2, and 3, and 1-hour rated Thermo-Lag 330-1 electrical raceway 
fire barrier (ERFB) material), in the specified 20 feet of separation 
protected with fire detection and automatic water-based fire 
suppression between redundant safe-shutdown trains.
    The redundant trains are separated by a horizontal distance of 20 
feet with intervening combustibles in certain fire zones in the Units 
1, 2, and 3 RBs.

[[Page 16833]]

Exemptions are requested from the requirements to provide 20 feet of 
separation, free of intervening combustibles. The following is a list 
of those fire zone locations and intervening combustibles/fire hazards 
present within a 20-foot spatial separation zone for redundant safe-
shutdown trains:

 Unit 1 Fire Zone 1-1/1-2....  565' Elevation.........  480V (RB) Vent Board 1B.
 Unit 1 Fire Zone 1-1/1-2....  565' Elevation.........  1-LPLN-925-338 & 338A Process Radiation Monitor
                                                                 and Relay Panel.
 Unit 1 Fire Zone 1-1/1-2....  565' Elevation.........  Thermo-Lag on Conduits ES2625-II and ES2673-II.
 Unit 1 Fire Zone 1-3/1-4....  593' Elevation.........  Thermo-Lag on Conduits PP459-IA, PP460-IA, and
                                                                 ES125-I.
 Unit 1 Fire Zone 1-3/1-4....  593' Elevation.........  1-LPLN-925-0281A Fire Detection Panel.
 Unit 1 Fire Zone 1-3/1-4....  593' Elevation.........  1-LPLN-925-0315 Heat Detection Panel.
 Unit 2 Fire Zone 2-1/2-4....  565' Elevation.........  480V (RB) Vent Board 2B.
 Unit 2 Fire Zone 2-1/2-2....  565' Elevation.........  2-PWR-276-0007 480V Power Distribution Panel.
 Unit 2 Fire Zone 2-3/2-4....  593' Elevation.........  25-281A Fire Detection Panel.
 Unit 2 Fire Zone 2-3/2-4....  593' Elevation.........  25-316 Cable Tray Fire Detection Control.
 Unit 3 Fire Zone 3-1/3-2....  565' Elevation.........  480 V (RB) Vent Board 3B.
 Unit 3 Fire Zone 3-1/3-2....  565' Elevation.........  1-LPLN-925-336 & 336A Raw Cooling Water Effluent
                                                                 Radiation Monitor and Relay Panel.
 Unit 3 Fire Zone 3-1/3-2....  565' Elevation.........  1-LPLN-925-337 & 337A Process Radiation Monitor
                                                                 and Relay Panel.
 

    To justify inclusion of intervening combustibles in RB fire areas, 
the licensee performed fire modeling to assess potential hazards using 
methodology from NUREG-1805, ``Fire Dynamics Tools (FDTs) Quantitative 
Fire Hazard Analysis Methods for the U.S. Nuclear Regulatory Commission 
Fire Protection Inspection Program,'' December 2004. Enclosure 2 of the 
exemption request discussed the fire-risk analysis for the Units 1, 2, 
and 3 RBs.
    TVA provided an assessment utilizing fire modeling to evaluate the 
fire hazards due to intervening combustibles between redundant cable 
trains in the RBs. In this fire modeling analysis, the licensee modeled 
fire in Unit 1 RB Elevation 565' in the 20-foot zone of separation 
between fire zones 1-1 and 1-2.\1\ Specifically, 480V (RB) vent boards 
1B, 2B, and 3B are located within the 20-foot zone of separation. The 
fire model uses a series of empirical correlations from NUREG-1805 to 
show the largest fire from a vertical low voltage electrical cabinet 
should not produce enough radiant energy to ignite the closest 
redundant cable trays or intervening combustibles within the redundant 
trains.
---------------------------------------------------------------------------

    \1\ The Units 2 and 3 configuration are very similar and the 
results of this analysis are applicable to 480V (RB) vent board 2B 
and 480V (RB) vent board 3B.
---------------------------------------------------------------------------

    The analysis is used to determine the extent of the potential fire 
damage associated with a realistic worst case fire scenario between 
Unit 1 RB fire zones 1-1 and 1-2 and the anticipated failure of cables 
or equipment of redundant trains of systems required for safe-shutdown. 
A fire scenario was postulated for the Unit 1 RB, that is, fire started 
in a vertical electrical cabinet (480V RB vent board 1B). This cabinet 
has 12 vertical sections with no vent openings. The penetrations in the 
cabinet consist of sealed conduits on top of the cabinet. The fire 
started from non-qualified Institute of Electronics and Electrical 
Engineering Standard (IEEE)-383 cables within the cabinet and was 
assumed to be limited to one cable bundle. The heat release rate (HRR) 
\2\ used to calculate heat fluxes to the targets (cable trays located 
at radial distance of approximately 7 feet [17 feet above floor], 
conduits located at the bottom of the duct approximately 9 feet above 
the top of the cabinet, and Thermo-Lag 330-1 wrapped conduit located 
approximately 7 feet from the edge of the cabinet) was based on Table 
E-4 in Appendix E of NUREG/CR-6850 (EPRI [Electric Power Research 
Institute] TR-1019181), ``EPRI/NRC-RES Fire PRA [Probabilistic Risk 
Analysis] Methodology for Nuclear Power Facilities,'' November 2005.
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    \2\ HRR is the rate at which heat energy is generated by 
burning. The HRR of a fuel is related to its chemistry, physical 
form, and availability of oxidant. When an object burns, it releases 
a certain amount of energy per unit of time. For most materials, the 
HRR of a fuel changes with time, in relation to its chemistry, 
physical form, and availability of oxidant (air), and is ordinarily 
expressed as kW (kJ/sec) or Btu/sec and denoted by Q (1,000 kW = 1 
MW or 1 BTU/sec = 1.055 kW).
---------------------------------------------------------------------------

    In order to evaluate the licensee's conclusion that a cabinet fire 
would not result in fire damage adversely affecting the safe-shutdown 
capability in Units 1, 2, and 3 RB located within the 20-foot 
separation area, the NRC staff identified areas in which additional 
information was necessary to complete its evaluation. The NRC staff had 
discussions with the licensee on November 20, 2006, concerning use of 
the HRR of a single bundle cable (vs. multiple bundles) fire from 
NUREG/CR-6850 in fire modeling. Specifically, the NRC staff requested 
TVA to justify how the single bundle cable HRR assumption bounds the 
worst case cabinet fire scenario. On January 11, 2007 (ADAMS Accession 
Number ML070160050), TVA provided a revised fire model to address the 
NRC concerns.
    In the revised fire modeling analysis, the HRR for multiple-cable 
bundles was assumed due to multiple conduit entries in each section of 
the low voltage vertical cabinet. The HRR associated with multiple-
cable bundles for a vertical cabinet with non-qualified IEEE-383 cables 
was based on Table E-5 in Appendix E of NUREG/CR-6850. The critical 
incident radiative heat flux \3\ for ignition is calculated from the 
cabinet fire scenario to see if ignition of the redundant cables and 
adjacent surrounding targets (intervening combustibles) is possible. 
The critical incident radiative heat flux from the maximum fire HRR, 
that is, 816 Kilowatt (kW), was estimated at 4.28 kW/m2.
---------------------------------------------------------------------------

    \3\ The incident heat flux (the rate of heat transfer per unit 
area that is normal to the direction of heat flow--it is a total of 
heat transmitted by radiation, conduction, and convection) required 
to raise the surface of a target to a critical temperature is termed 
the critical heat flux. Below this heat flux an object will 
typically not ignite while above this heat flux the time to ignition 
will decrease with the increasing heat flux.
---------------------------------------------------------------------------

    The licensee determined that the maximum radiant heat flux is not 
sufficient to ignite non-qualified IEEE-383 cable or Thermo-Lag 330-1 
wrapped on conduits or safety-related cables or equipment of redundant 
trains of systems for safe-shutdown, nor to adversely impact any 
surrounding equipment. The targets require a large amount of radiative 
heat to ignite. The measured critical heat flux level for 
representative non-qualified IEEE-383 or thermoplastic cable samples 
typically is in the range of 6 kW/m2 (NUREG/CR-6850, 
Appendix H, Table H-1). The measured critical heat flux for ignition 
for Thermo-Lag 330-1 ERFB material is 25 kW/m2 based on 
American Society of Testing and Materials (ASTM) E1321, ``Standard Test 
Method for Determining Material Ignition and Flame Spread

[[Page 16834]]

Properties'' (TVA October 26, 2006 (ADAMS ML063040310)).
    Based on the above evaluation, the NRC staff concludes that the 
ability of Units 1, 2, and 3 to achieve and maintain safe-shutdown 
conditions in accordance with the requirements of Section III.G.2.b to 
Appendix R to 10 CFR 50 is not adversely affected by the inclusion of 
intervening combustibles or fire hazards in certain fire zones within 
Units 1, 2, and 3 RBs for the following reasons:

--The fire modeling performed by the licensee provides reasonable 
assurance that redundant safe-shutdown trains will be maintained free 
of fire damage. This is because the estimated heat flux from the 
maximum exposure fire is less than the critical heat flux for ignition 
for non-qualified IEEE-383 cable or Thermo-Lag 330-1 ERFB material.
--In the event of a postulated fire in the Units 1, 2, and 3 RBs, all 
units can safely shut down using the alternate shutdown panel located 
outside each RB. The Browns Ferry Nuclear Plant Appendix R alternate 
shutdown strategy is described in the approved fire protection plan.
--A significant fire is unlikely due to control of transient 
combustibles near the redundant trains. RB volume and height would 
dissipate heat from a cabinet fire and not threaten redundant trains. 
Smoke detectors and portable extinguishers were installed for quick 
fire detection and suppression. All electrical cabinets in the area of 
concern are enclosed with no ventilation openings and the bottom of the 
cable tray stacks have non-combustible covers.
--A fire originating in a low voltage cabinet exposing intervening 
combustibles/targets (cable trays located at radial distance of 
approximately 7 feet, conduits located at the bottom of the duct 
approximately 9 feet above the top of the cabinet (17 feet above 
floor), and Thermo-Lag 330-1 wrapped conduit located approximately 7 
feet from the edge of the cabinet) would be slow to develop. Based on 
the fire detection arrangement in the Units 1, 2, and 3 RBs, detection 
of this type of fire would occur well before the fire had time to 
develop into a fully developed cable tray fire scenario.
--The NRC staff reviewed the physical configuration of the Units 1, 2, 
and 3 RBs, the associated fire hazards (intervening combustibles) and 
fire protection features, and fire response procedures. This review 
found that a fire that initiated in one of the cabinets would likely be 
detected in its incipient stage, and fire-fighting activities initiated 
(including actuation of the automatic water-based fire suppression 
system) before the fire becomes fully developed, thereby limiting its 
potential to spread.

    The NRC staff, therefore, finds the licensee's proposed exemption 
to permit intervening combustibles in the 20-foot separation zone for 
certain specified fire areas in the Units 1, 2, and 3 RBs acceptable.
    The licensee indicated that all fire zones discussed previously are 
protected with fire detection and automatic pre-action sprinkler 
systems, manual fire extinguishers, and hose stations. If a fire were 
to occur in any of these locations it would be detected before 
significant flame propagation or increased temperature, radiative heat 
flux, and damaging smoke layering occurred. The fire brigade would then 
extinguish the fire using hose stations and manual fire fighting 
equipment. If rapid fire propagation occurred before the arrival of the 
fire brigade, one would expect the automatic pre-action sprinkler 
system to actuate and limit fire spread. Pending actuation of automatic 
pre-action sprinkler system, the physical separation of redundant 
trains is sufficient to provide reasonable assurance that one safe-
shutdown train would remain free of fire damage. Therefore, the NRC 
staff concludes that the existing level of fire protection for the 
redundant safe-shutdown trains is an acceptable deviation from Section 
III.G.2 of Appendix R to 10 CFR Part 50.

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. These include the special 
circumstances that the underlying purpose of the rule is satisfied by 
the requested revision to the exemption, since the existing fire 
protection features and analyses demonstrate that the quantity of 
intervening combustibles permitted in the 20-foot separation zone does 
not affect the ability of the existing fire protection features to 
provide an equivalent level of protection as required by 10 CFR 50, 
Appendix R, Section III.G.

Authorized by Law

    This exemption revision allows the existence of the specified 
intervening combustibles in the 20-foot separation zone identified 
previously. As stated above, 10 CFR 50.12 allows the NRC to grant 
exemptions from the requirements of 10 CFR 50.48 and Appendix R to 10 
CFR 50. The NRC staff has determined that granting of the licensee's 
proposed exemption will not result in a violation of 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 10 CFR 50.48 is to limit fire damage to 
structures, systems, and components (SSCs) important to safety so that 
the capability to shut down the plant safely is ensured. Compliance 
with the applicable provisions of Appendix R to Part 50 ensures that 
one train of cables and equipment necessary to achieve and maintain 
safe-shutdown are maintained free of fire damage. Based on the above, 
no new accident precursors are created by allowing the specified 
intervening combustibles into the 20-foot separation zone identified 
previously, thus, the probability of postulated accidents is not 
increased. Also, based on the above, the consequences of postulated 
accidents are not increased. Therefore, there is no undue risk to 
public health and safety.

Consistent With Common Defense and Security

    The proposed exemption revision would allow the specified 
intervening combustibles into the 20-foot separation zone identified 
previously. This revision to the fire protection plan and existing 
exemptions has no relation to security issues. Therefore, the common 
defense and security are not impacted by this exemption.

Special Circumstances

    In accordance with 10 CFR 50.12(a)(2), special circumstances are 
present whenever application of the regulation in the particular 
circumstances is not necessary to achieve the underlying purpose of the 
rule. The underlying purpose of 10 CFR 50.48 is to limit fire damage to 
SSCs important to safety so that the capability to shut down the plant 
safely is ensured. Compliance with the applicable provisions of 
Appendix R to Part 50 ensures that one train of cables and equipment 
necessary to achieve and maintain safe-shutdown are maintained free of 
fire damage. As the existence of

[[Page 16835]]

the intervening combustibles should not affect the capability of the 
installed suppression and detection system to detect and mitigate a 
fire, the underlying purpose of 10 CFR 50.48 and Appendix R is 
achieved. Therefore, the special circumstances required by 10 CFR 
50.12(a)(2) for the granting of an exemption from 10 CFR 50.48 and 
Appendix R to 10 CFR 50 exist.

4.0 Conclusion

    Accordingly, the Commission has determined that, pursuant to 10 CFR 
50.12, the revision to 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. Also, special 
circumstances are present. Therefore, the Commission hereby grants the 
TVA a revision to the exemption from the requirements of Section 
III.G.2 of Appendix R to 10 CFR 50 for the Browns Ferry Nuclear Plant, 
Units 1, 2 and 3.
    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 (22 FR 9036).
    This exemption is effective upon issuance.

    Dated at Rockville, Maryland, this 29th day of March 2007.
    For the Nuclear Regulatory Commission.
Catherine Haney,
Director, Division of Operating Reactor Licensing, Office of Nuclear 
Reactor Regulation.
[FR Doc. 07-1696 Filed 4-4-07; 8:45 am]
BILLING CODE 7590-01-P