ML083030336

Issuance of Amendment Regarding Ice Condenser Licensing Basis

ML083030336
Person / Time
Site:	Watts Bar
Issue date:	01/06/2009
From:	John Lamb Division of Operating Reactor Licensing
To:	Campbell W Tennessee Valley Authority
Lamb John G./NRR/DORL, 415-3100
References
TAC MD9715
Download: ML083030336 (13)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 January 6, 2009 Mr. William R. Campbell, Jr.

Chief Nuclear Officer and Executive Vice President Tennessee Valley Authority 6A Lookout Place 1101 Market Street Chattanooga, TN 37402-2801 SUB"IECT:

WATTS BAR NUCLEAR PLANT, UNIT 1 -

ISSUANCE OF AMENDMENT REGARDING ICE CONDENSER LICENSING BASIS (TAC NO. MD9715)

Dear Mr. Campbell:

The U.S. Nuclear Regulatory Commission has issued the enclosed Amendment No. 73 to Facility Operating License No. NPF-90 for Watts Bar Nuclear Plant (WBN), Unit 1. This amendment is in response to your application dated September 19, 2008 (Agencywide Document and Access Management System Accession No. ML082670544).

The amendment modifies the WBN Final Safety Analysis Report by requiring an inspection of the ice condenser within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of experiencing a seismic event greater than or equal to an Operating Basis Earthquake within the 5-week period after ice basket replenishment has been completed to confirm that adverse ice fallout has not occurred that could impede the ability of the ice condenser lower inlet doors to open.

A copy of the safety evaluation is also enclosed. Notice of issuance will be included in the Commission's biweekly Federal Register notice.

G. Lamb, Senior Project Manager tts Bar Special Projects Branch vision of Operating Reactor Licensing ffice of Nuclear Reactor Regulation Docket No. 50-390

Enclosures:

1. Amendment No. 73 to NPF-90

2. Safety Evaluation cc w/enclosures: Distribution via Listserv

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 TENNESSEE VALLEY AUTHORITY DOCKET NO. 50-390 WATTS BAR NUCLEAR PLANT. UNIT 1 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 73 License No. NPF-90

1.

The Nuclear Regulatory Commission (the Commission) has found that:

A.

The application for amendment by Tennessee Valley Authority (the licensee) dated September 19, 2008, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commission's rules and regulations set forth in 10 CFR Chapter I; B.

The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C.

There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commission's regulations; D.

The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and E.

The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commission's regulations and all applicable requirements have been satisfied.

3

2.

Accordingly, the license is amended by changes to the Facility Operating License as indicated in the attachment to this license amendment, and paragraph 2.C.(2) of Facility Operating License No. NPF-90 is hereby amended to read as follows:

(2)

Technical Specifications and Environmental Protection Plan The Technical Specifications contained in Appendices A and B, as revised through Amendment No. 73, and the Environmental Protection Plan contained in Appendix B, both of which are attached hereto, are hereby incorporated into this license. TVA shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan.

3.

Further, Facility Operating License No. NPF-90 is hereby amended to authorize a change to the Final Safety Analysis Report (FSAR) to allow inspection of each ice condenser within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of experiencing a seismic event greater than or equal to an operating-basis earthquake within the 5-week period after ice basket replenishment has been completed to confirm that adverse ice fallout has not occurred which could impede the ability of the ice condenser lower inlet doors to open. This action would be taken, in lieu of requiring a 5-week waiting period following ice basket replenishment, prior to beginning ascension to power operations, as set forth in the license amendment application dated September 19, 2008, and evaluated in the safety evaluation dated January 06,2009. The licensee shall update the FSAR by adding a description of this change, as authorized by this amendment, and in accordance with 10 CFR 50.71(e).

4.

This license amendment is effective as of the date of its issuance, and shall be implemented no later than 45 days from the date of its issuance.

FOR THE NUCLEAR REGULATORY COMMISSION L. Raghavan, Chief Watts Bar Special Projects Branch Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

Attachment:

Changes to the Operating License Date of Issuance: January 6, 2009

ATTACHMENT TO AMENDMENT N0.73 FACILITY OPERATING LICENSE NO. NPF-90 DOCKET NO. 50-390 Replace Page 3 of Operating License NPF-90 with the attached Page 3.

3 (4)

TVA, pursuant to the Act and 10 CFR Parts 30, 40 and 70, to receive, possess, and use in amounts as required, any byproduct, source or special nuclear material without restriction to chemical or physical form, for sample analysis, instrument calibration, or other activity associated with radioactive apparatus or components; and (5)

TVA, pursuant to the Act and 10 CFR Parts 30, 40 and 70, to possess, but not separate, such byproduct and special nuclear materials as may be produced by the operation of the facility.

C.

This license shall be deemed to contain and is subject to the conditions specified in the Commission's regulations set forth in 10 CFR Chapter I and is subject to all applicable provisions of the Act and to the rules, regulations, and orders of the Commission now or hereafter in effect, and is subject to the additional conditions specified or incorporated below.

(1 )

Maximum Power Level TVA is authorized to operate the facility at reactor core power levels not in excess of 3459 megawatts thermal.

(2)

Technical Specifications and Environmental Protection Plan The Technical Specifications contained in Appendix A as revised through Amendment No. 73 and the Environmental Protection Plan contained in Appendix B, both of which are attached hereto, are hereby incorporated into this license. TVA shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan.

(3)

Safety Parameter Display System (SPDS) (Section 18.2 of SER Supplements 5 and 15)

Prior to startup following the first refueling outage, TVA shall accomplish the necessary activities, provide acceptable responses, and implement all proposed corrective actions related to having the Watts Bar Unit 1 SPDS operational.

(4)

Vehicle Bomb Control Program (Section 13.6.9 of SSER 20)

During the period of the exemption granted in paragraph 2.0.(3) of this license, in implementing the power ascension phase of the approved initial test program, TVA shall not exceed 50% power until the requirements of 10 CFR 73.55(c)(7) and (8) are fully implemented. TVA shall submit a letter under oath or affirmation when the requirements of 73.55(c)(7) and (8) have been fully implemented.

Amendment No. 73

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 73 TO FACILITY OPERATING LICENSE NO. NPF-90 TENNESSEE VALLEY AUTHORITY WATTS BAR NUCLEAR PLANT, UNIT 1 DOCKET NO. 50-390

1.0 INTRODUCTION

By letter dated September 19, 2008 (Agencywide Document and Access Management System Accession No. ML082670544), the Tennessee Valley Authority (the licensee), submitted a request for revisions to the Watts Bar Nuclear Plant (WBN), Unit 1, ice condenser licensing basis. The proposed revisions would authorize a change to the WBN Final Safety Analysis Report (FSAR) by requiring an inspection of the ice condenser within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of experiencing a seismic event greater than or equal to an Operating Basis Earthquake (OBE) within the 5-week period after ice basket replenishment has been completed to confirm that adverse ice fallout has not occurred that could impede the ability of the ice condenser lower inlet doors to open. This action would be taken, in lieu of requiring a 5-week waiting period following ice basket replenishment, prior to beginning ascension to power operations following an outage.

The U.S. Nuclear Regulatory Commission (NRC) staff's proposed no significant hazards consideration determination was published in the Federal Register on November 4,2008 (73 FR 65698).

2.0 REGULATORY EVALUATION

Section 3.1 of the WBI\\J Unit 1 FSAR, "Conformance with NRC General Design Criteria,"

discusses briefly the design criteria for structures, systems, and components (SSCs) important to safety and how these criteria meet the NRC "General Design Criteria for Nuclear Power Plants" specified in Appendix A to Title 10 of the Code of Federal Regulations (10 CFR), Part 50.

The proposed amendment does not alter or revise the current bounding safety analyses of record in any way. Consequently, WBN Unit 1 will remain in compliance with the applicable regulations and requirements including the following General Design Criteria (GDC):

GDC 2, "Design Basis For Protection Against Natural Phenomena," which requires that SSCs important to safety be designed to withstand the effects of natural phenomena such as earthquakes; GDC 16, "Containment Design," which requires that the reactor containment and associated systems provide an essentially leak-tight barrier against the uncontrolled release of radioactivity to the environment;

- 2 GDC 38, "Containment Heat Removal," which requires that a system be provided to remove heat from the reactor containment; and GDC 50, "Containment Design Basis," which requires that the reactor containment structure be designed with conservatism to accommodate applicable design parameters (pressure, temperature, leakage rate).

Other than what may be construed as licensing basis, there is no specific regulation, NRC policy, or guidance document that clearly and unambiguously pertains to ice condenser ice fusion time requirements.

3.0 TECHNICAL EVALUATION

3.1 Ice Condenser Design Features and Ice Bed Issues In the September 19, 2008, application, the licensee provided a general description of ice condenser design and its operation during a loss-of-coolant accident (LOCA) or a high energy line break (HELB). Since the purpose of the proposed amendment is not to change any design of the ice condenser, the licensee's general description is not repeated here.

The licensee stated that, as a result of sublimation of ice in the ice bed during normal operation, periodic addition of ice mass is necessary to ensure compliance with the Technical Specifications (TSs). At WBN Unit 1, this is accomplished by emptying and refilling select ice baskets during each refueling outage (RFO). The population of baskets affected during a given RFO is typically 10 to 20 percent of the total.

The term "ice fusion" refers to a condition in which an ice basket freshly loaded with flake ice achieves stability at the operating temperature of the ice condenser (i.e., when the ice freezes or otherwise solidifies such that it tends to stay in the ice basket when agitated). The design of the ice condenser lower inlet doors, as currently described in the FSAR, includes sufficient clearance to accommodate ice fallout from baskets of fused ice in the event of a seismic disturbance occurring coincident with a LOCA or a HELB.

If the ice in the baskets was not sufficiently fused during a design-basis earthquake (DBE), it is possible that an excessive amount of ice would fall from the baskets and impair operability of the ice condenser. Excessive ice fallout could potentially block the lower inlet doors, block the floor drains, restrict compression of the shock absorber assemblies, block flow channels, and decrease the ice mass in the ice baskets.

3.2 Brief Chronology of Ice Condenser Issues at WBN Unit 1 As part of the original ice condenser qualification program, seismic testing of fused ice baskets was conducted by Westinghouse to determine the amount of ice fallout from ice baskets subjected to simulated plant time-history seismic disturbances. Test results were reported in Topical Report WCAP-8110, Supplement 9, dated May 1974. The test program did not determine a minimum time requirement for ice fusion.

In a letter dated November 21, 1974, the Atomic Energy Commission (AEC, now NRC) issued a safety evaluation report (SER) on Supplement 9 of Topical Report WCAP-8110, stating that "... the data presented in WCAP-811 0 Supplement 9 are adequate to conclude that

- 3 land-based plants using ice condenser type containments should begin their initial ascent to power after a minimum of 5-weeks following ice loading." Despite what the AEC staff stated in the SER, the Westinghouse ice condenser program did not determine a minimum time requirement for ice fusion. The November 21, 1974, letter above accepts the document as a topical report that may be referenced in license applications. The WBI\\l Unit 1 FSAR references WCAP-8110, Supplement 9.

The NRC accepted the WBN Unit 1 ice condenser design in NUREG-0847, "Safety Evaluation Report related to the operation of Watts Bar Nuclear Plant, Units 1 and 2." On February 7, 1996, the I\\lRC issued the operating license for WBI\\l Unit 1. However, neither NUREG-0847 nor other Supplements issued by the NRC referenced Supplement 9 of Westinghouse Topical Report WCAP-8110. Further, neither NUREG-0847 nor its supplements specifically addressed ice storage time to achieve acceptable ice fusion prior to power ascension.

3.3 Licensee's Proposed Change to the Licensing Basis The licensee proposed to revise the licensing basis as described in the FSAR. The existing text of the WBN Unit 1 FSAR, Section 6.7.8.1, entitled "Lower Inlet Doors, Design Basis, Interface Requirements," reads as follows Sufficient clearance is required for doors to open into the ice condenser. Items to be considered in this interface are floor clearance, lower support, structure clearance and floor drain operation and sufficient clearance (approximately six inches) to accommodate ice fallout in the event of a seismic disturbance occurring coincident with a loss-of-coolant accident.

The licensee's proposed revision to this paragraph will read (new text in italics):

Sufficient clearance is required for doors to open into the ice condenser. Items to be considered in this interface are floor clearance, lower support, structure clearance and floor drain operation and sufficient clearance (approximately six inches) to accommodate ice fallout in the event of a seismic disturbance occurring coincident with a loss-of-coolant accident. Original ice basket qualification testing (Topical Report WCAP-81 10, Supplement 9-A) has shown freshly loaded ice is considered fused after five weeks. In the event of an earthquake (OBE or greater) which occurs within five weeks following the completion of ice basket replenishment, plant procedures require a visual inspection of applicable areas of the ice condenser within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to confirm that opening of the ice condenser lower inlet doors is not impeded by any ice fallout resulting from the seismic disturbance. The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> time frame for inspection is applicable during modes where the lower inlet doors are required to be operable; otherwise perform this inspection prior to startup. This alternative method of compliance with the requirements of GOG 2 is credible based upon the reasonable assurance that the ice condenser doors will open following a seismic event during the 5 week period and the low probability of a seismic event occurring coincident with or subsequently followed by a Design Basis Accident.

During its review of the FSAR change against the requirements of 10 CFR 50.59, the licensee recognized that the interface requirements for the ice condenser lower inlet doors will no longer

-4 be met solely by the original qualification testing, but will also rely on conservatisms in the original ice basket seismic testing, the licensee's practical experience with ice fusion gained through decades of ice condenser operation, and design features of the ice condenser.

Accordingly, and upon issuance of the requested amendment, the licensee will implement procedural requirements that, in the event of an OBE or greater seismic disturbance within 5 weeks of loading ice baskets, the ice condenser would be inspected within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to ensure that no ice fallout has occurred that could impede proper functioning of the ice condenser lower inlet doors.

3.4 NRC Staff's Evaluation of Proposed FSAR Revision 3.4.1 Ice Fusion The term "ice fusion" refers to a condition in which an ice basket freshly loaded with flake ice achieves stability at the operating temperature of the ice condenser (Le., when the ice freezes or otherwise solidifies such that it tends to stay in the ice basket when agitated). The licensee stated that the design of the lower inlet doors, as currently described in the FSAR, includes sufficient clearance to accommodate ice fallout from baskets of fused ice in the event of a seismic disturbance occurring coincident with a LOCA or a HELB.

If the ice in the baskets was not sufficiently fused during a DBE, it is possible that an excessive amount of ice would fall from the baskets and impair operability of the ice condenser. Excessive ice fallout could potentially block the lower inlet doors, block the floor drains, restrict compression of the shock absorber assemblies, block flow channels, or decrease the ice mass in the ice baskets.

As stated in Section 3.2, the basis of the 5-week ice fusion time "requirement" was derived from the original seismic qualification of ice condenser ice baskets conducted by Westinghouse in 1974, even though determination of a minimum ice fusion time was not an objective of the test program. Instead, the results of acceptable ice fallout tests conducted on ice baskets loaded for periods of 6 to 71'2 weeks were used by the AEC staff to establish a "preoperational limit for minimum storage time" of ice baskets prior to initial power ascension.

As a result of a recent review of the test results documented in WCAP-811 0, Supplement 9, the licensee has concluded that the 5-week ice fusion time selected as the licensing basis is conservative and that the ice condenser design has substantial margin with respect to ice fallout.

The licensee provided the following key considerations in reaching this conclusion:

The test baskets floated freely in the lattice frames and were not fixed at one end. The floating end exacerbates the movement resulting from application of a given seismic excitation, which would tend to overstate the ice fallout in the test compared to expected fallout from an actual plant event.

The test basket was only six feet tall and had an open top, whereas an actual ice condenser basket at W BN typically consists of four vertically stacked 12-foot sections, with only the uppermost section having an open top. The majority of ice fallout during the tests occurred from the open top of the basket where it spilled out from the top 12-inches through the open top. Since proportionally less ice would be expected to fall out of the lower three sections of an actual ice condenser basket, the percentage of ice falling out

- 5 of the test basket section overstates what would be expected during an actual plant event. The acceptance criteria for this initial testing was to verify that no more than 1-percent of the ice mass exited the basket during a seismic event.

In addition to the conservatisms built into the 1974 test program, there is additional conservatism provided by the WBN ice basket maintenance practice. The practice used is to add ice to the voids in the lower portions of the baskets by a thermal drilling process rather than to fully empty and reload baskets. The amount of fresh ice added to any individual basket during servicing is typically 10-20 percent of the amount required for a complete basket fill. As such, there is significantly less "loose" ice in a serviced basket than the configuration tested. Therefore the likelihood of any substantial ice fallout from these baskets is minimal.

The NRC staff reviewed the analysis the licensee presented on ice fusion. The licensee's experience with ice behavior in its ice condensers has demonstrated that there is excessive conservatism in the 5-week ice fusion time "requirement." The NRC staff finds that the 5-week ice fusion time "requirement" for newly added ice is conservative. The "requirement" can be eliminated without any negative impact on the performance of the ice condenser, provided the licensee inspects the ice condenser within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of a seismic event greater than the OBE.

The inspection provides reasonable assurance the ice condenser will perform its intended function following a DBE. If the inspection finds excessive ice fallout or damage to the ice condenser, the licensee will shut down the unit and make the necessary repairs.

3.4.2 Effect of Ice Fallout on Lower Inlet Door Performance The redundancy of flow paths in the ice condenser provides reasonable assurance that the ice condenser would perform its function even if some lower inlet doors were partially degraded.

A total of 48 Lower Inlet Doors (2 per bay) exist in the WBN Unit 1 Ice Condenser. The licensee analysis assumed that only a small portion of these doors would be obstructed from fully opening in a seismic event, and the licensee assumed that 33-percent ice fallout would occur from the serviced baskets. In the event that 33-percent of the new ice added to the baskets during servicing were to fall out, the licensee analysis resulted in an ice level not to exceed more than approximately 8 inches. The licensee concluded that the lower inlet doors may be partially obstructed from fUlly opening, but should continue to open to a lesser degree and the opening force on the door would relocate the ice immediately behind the doors to a point beyond the floor-mounted turning vanes.

The NRC staff reviewed the design of the lower inlet doors, and finds that the doors would require a large amount of ice to block their free movement. This large amount is not likely shaken loose from the ice baskets even in an OBE.

3.4.3 Blocking of Floor Drains The licensee stated that, as discussed in the FSAR, the impact of floor drain blockage by excessive ice fallout would be negligible. As discussed in the WBN Unit 1 FSAR, containment peak pressure is not affected by drain performance. There are a total of 20 ice condenser floor drains among the 24 ice condenser bays. The ice condenser design is such that for blockage of any floor drain, water would flow to adjacent bays and eventually would spill over the lower inlet

- 6 door openings if necessary. Additionally, any ice on the floor of the ice condenser would be melted by the rise in temperature of the ice condenser and flowing meltwater. The licensee, thus, surmised that there would be no adverse impact on the ice condenser function for blockage of the floor drains from fallout of ice in the ice baskets.

The NRC staff finds that any ice on the floor of the ice condenser will quickly melt in the post-LOCA or post-HELB environment. This fact, plus the availability of multiple floor drains, will assure that the floor drains will not be blocked to hamper the design function of the ice condenser.

3.4.4 Blocking of Flow Channels The licensee stated that the successful completion of WBN Unit 1 TSs Surveillance Requirement 3.6.11.4 ensures that the ice accumulation on the structural steel members comprising flow channels through the ice bed is less than or equal to a 15-percent blockage of the total flow area for each safety analysis section. In addition, flow channels will be inspected for blockage in the required post-seismic event inspection of the ice condenser.

Therefore, it can be reasonably assumed that any loose, granular ice that would be shaken free during a seismic event from a recently replenished ice basket cannot block flow passages that were verified to be at least 85-percent clear during the preceding surveillance inspection.

The NRC staff finds that any ice on the flow channels of the ice condenser will quickly melt in the post-LOCA or post-high energy line break environment. Thus, the flow channels will not be blocked by ice fallout to hamper the design function of the ice condenser.

3.4.5 Decrease of Ice Mass in the Ice Baskets The licensee stated that any fallout from the ice baskets would remain within the ice condenser.

Although the ice would no longer be in the ice baskets, its mass would remain available to absorb energy from a LOCA or a HELB.

The NRC staff finds that ice fallout from the ice basket, regardless of quantity, is not a mechanism to reduce ice inventory in the ice condenser. Therefore, the required quantity of ice will continue to be present to ensure that the ice condenser design function is carried out in a LOCA or HELB. In addition, following an OBE, the licensee's inspection procedure will require a visual inspection of all applicable areas of the ice condensers within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

3.5 Summary of NRC Staff's Evaluation As explained in Section 3.2 above, the original ice condenser basket seismic qualification, and the AEC/NRC review of the same, led to a 5-week storage time "requirement" for freshly loaded ice baskets prior to power ascension. However, conservatisms in the original testing and anecdotal evidence from ice condenser experience suggest that freshly loaded, wet flake ice will adequately solidify in the ice baskets much sooner than 5 weeks. In addition, design features of the ice condenser are such that the lower inlet doors will not be blocked by ice fallout from a seismic event.

- 7 Based on the above review, the NRC staff finds the revision to the WBN Unit 1 licensing basis and changes to the WBI\\I Unit 1 FSAR pertaining to ice condenser ice fusion time acceptable.

The licensing basis regarding ice condenser ice fusion time is revised as depicted in the licensee's letter to the NRC, dated September 19, 2008. This revision to the licensing basis shall be incorporated into the Final Safety Analysis Report in accordance with the update requirements specified by 10 CFR 50.71(e).

4.0 STATE CONSULTATION

In accordance with the Commission's regulations, the Tennessee state official was notified of the proposed issuance of the amendment. The State official had no comments.

5.0 ENVIRONMENTAL CONSIDERATION

The amendment changes a requirement with respect to the installation or use of facility components located within the restricted area as defined in 10 CFR Part 20. The NRC staff has determined that the amendment involves no significant increase in the amounts and no significant change in the types of any effluents that may be released offsite and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendments involve no significant hazards consideration, and there has been no public comment on such finding (73 FR 65698). Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendments.

6.0 CONCLUSION

The Commission has concluded, on the basis of the considerations discussed above, that (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

Principal contributors: G. Armstrong D. Harrison J. Lamb Date: January 6, 2009

January 6, 2008 Mr. William R. Campbell, Jr.

Chief Nuclear Officer and Executive Vice President Tennessee Valley Authority 6A Lookout Place 1101 Market Street Chattanooga, TI'J 37402-2801 SUB..IECT:

WATTS BAR NUCLEAR PLANT, UI'JIT 1 -ISSUANCE OF AMENDMENT REGARDING ICE CONDENSER LICENSING BASIS (TAC NO. MD9715)

Dear Mr. Campbell:

The U.S. Nuclear Regulatory Commission has issued the enclosed Amendment No. 73 to Facility Operating License No. NPF-90 for Watts Bar Nuclear Plant (WBN), Unit 1. This amendment is in response to your application dated September 19, 2008 (Agencywide Document and Access Management System Accession No. ML082670544).

The amendment modifies the WBN Final Safety Analysis Report by requiring an inspection of the ice condenser within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of experiencing a seismic event greater than or equal to an Operating Basis Earthquake within the 5-week period after ice basket replenishment has been completed to confirm that adverse ice fallout has not occurred that could impede the ability of the ice condenser lower inlet doors to open.

A copy of the safety evaluation is also enclosed. Notice of issuance will be included in the Commission's biweekly Federal Register notice.

Sincerely, IRA!

John G. Lamb, Senior Project Manager Watts Bar Special Projects Branch Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-390

Enclosures:

1. Amendment No. 73 to NPF-90

2. Safety Evaluation cc w/enclosures: Distribution via Listserv DISTRIBUTION:

PUBLIC LPWB Reading File Ridsl'J rrDorl Lpwb RidsN rrPMJ Lamb Accession Number*

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~Lamb BClayton DHarrison AJones PMilano for LRaghavan DATE 12/09/08 12/09/08 12/08/08 12/31/08 01/06/09 OFFICIAL AGENCY RECORD