NRC-2011-0029, License Amendment Request 241, Alternative Source Term, Revision of Previous Commitment
| ML110730295 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 03/11/2011 |
| From: | Meyer L Point Beach |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NRC-2011-0029 | |
| Download: ML110730295 (6) | |
Text
March 11,201 1 NRC 201 1-0029 10 CFR 50.90 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 Point Beach Nuclear Plant, Units I and 2 Dockets 50-266 and 50-301 Renewed License Nos. DPR-24 and DPR-27 License Amendment Request 241 Alternative Source Term Revision of Previous Commitment
References:
( 1 FPL Energy Point Beach, LLC letter to NRC, dated December 8,2008, License Amendment Request 241, Alternative Source Term (ML083450683)
(2)
NextEra Energy Point Beach, LLC letter to NRC, dated September 4,2009, License Amendment Request 241, Alternative Source Term, Response to Request for Additional lnformation (ML092510118)
(3)
NextEra Energy Point Beach, LLC letter to NRC, dated February 4, 2010, License Amendment Request 241, Alternative Source Term, Response to Request for Additional lnformation (MLI 00360065)
NextEra Energy Point Beach, LLC (NextEra) submitted License Amendment Request (LAR) 241 (Reference I ) to the NRC pursuant to 10 CFR 50.90. The license amendment would revise the current licensing basis to implement the alternative source term (AST) through reanalysis of the radiological consequences of the Point Beach Nuclear Plant (PBNP) Final Safety Analysis Report (FSAR) Chapter 14 accidents.
NextEra determined that certain information provided in docketed correspondence regarding the AST LAR requires clarification andlor revision. Enclosure 1 provides clarification of statements made in Reference (2) regarding passive electrical failure assumptions on electrical conductors and cables for the control room emergency filtration system (CREFS) and primary auxiliary building ventilation (VNPAB) system credited in the AST analyses. Enclosure 2 provides a revised Regulatory Commitment previously made in Reference (3) regarding administrative controls to ensure that the CREFS and VNPAB systems will not be in concurrent Technical Specification Action Conditions (TSACs).
NextEra Energy Point Beach, LLC, 6610 Nuclear Road, Two Rivers, WI 54241
Document Control Desk Page 2 Summary of Requlatow Commitments This letter contains no new Regulatory Commitments. The following Regulatory Commitment was made in NextEra's letter dated February 4, 201 0 (Reference 3):
o Administrative controls will be established to ensure that CREFS and the primary auxiliary building ventilation (VNPAB) system will not be in concurrent Technical Specification Action Conditions (TSACs) during planned preventive maintenance activities. These controls will be implemented following NRC approval of LAR 241, no later than the Unit 2 (201 1) refueling outage.
This Regulatory Commitment is revised as follows:
e Administrative controls will be established to ensure that CREFS and the primary auxiliary building ventilation (VNPAB) system will not be in concurrent Technical Specification Action Conditions (TSACs) during planned preventive maintenance activities on components of the CREFS and VNPAB systems. These administrative controls are not applicable to planned preventive maintenance activities performed on common support system components. These controls will be implemented following NRC approval of LAR 241, no later than the Unit 2 (201 1) refueling outage.
The information in this letter does not alter the no significant hazards consideration provided in Reference (1) and continues to satisfy the criteria of 10 CFR 51.22 for categorical exclusion from the requirements of an environmental assessment.
In accordance with 10 CFR 50.91, a copy of this letter is being provided to the designated Wisconsin Official.
I declare under penalty of perjury that the foregoing is true and correct.
Executed on March I 1,201 1.
Very truly yours, NextEra Energy Point Beach, LLC Enclosures cc:
Administrator, Region Ill, USNRC Project Manager, Point Beach Nuclear Plant, USNRC Resident Inspector, Point Beach Nuclear Plant, USNRC PSCW
ENCLOSURE I NEXTERA ENERGY POINT BEACH, LLC POINT BEACH NUCLEAR PLANT, UNITS I AND 2 LICENSE AMENDMENT REQUEST 241 ALTERNATIVE SOURCE TERM REVISION TO PREVIOUS STATEMENT REGARDING PASSIVE ELECTRICAL FAILURE ASSUMPTIONS FOR CREFS AND VNPAB NextEra Energy Point Beach, LLC (NextEra) determined that information provided in docketed correspondence regarding the alternative source term (AST) license amendment request (Reference I) requires clarification. The clarification is related to statements made in Reference (2) regarding passive electrical failure assumptions on electrical conductors and cables for the control room emergency filtration system (CREFS) and primary auxiliary building ventilation (VNPAB) system credited in the AST analyses. The statements from the NextEra Response to Question 4 (Enclosure 1 of Reference (2)) were:
(1)
'Modifications to CREFS in support of the AST LAR ensure that no. single active or passive failure of an electrical or control component, will prevent the system from performing its required function."
(2)
'Modifications to VNPAB in support of the AST LAR ensure that no. single active or passive failure of an electrical or control component, will prevent the system from performing its required function."
The original VNPAB and CREFS systems were designed and installed as non-safety related systems. These systems were not designed for active or passive single failures of structures and components and interacting systems. Although not part of the current design basis of the VNPAB and CREFS systems, improvements have been made as part of the upgrades to allow for redundancy of active system components, seismic upgrades and quality classification upgrades.
For the design of CREFS and VNPAB, certain non-safety related electrical conductors, cables and devices were not required to meet specific electrical separation criteria. Accordingly, NextEra clarifies that the electrical passive failures addressed in the modified design of the CREFS and VNPAB systems, and discussed in Reference (2), are non-mechanistic and do not include failure of one conductor, cable or device causing a failure of another conductor, cable or device in the same location or raceway.
The new Mode 5 CREFS and VNPAB design considers relay failures, failures of contacts to change state; shorting of contacts that change state; and shorting of relays, solenoids or starter coils that could cause a damper to change to an undesirable state or prevent starting of a fan.
Failures of de-energized solenoid valves or switches that do not change state for VNPAB and CREFS Mode 5 operation were not considered credible.
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For installed existing plant cables, components and control panel items, the design did not include changes to improve separation of conductor and components or internal control panel items associated with the CREFS and VNPAB. The existing standards for control panel wiring separation were retained. For CREFS and VNPAB, shorts were not considered for existing plant cables and conductors that were not replaced for the design. For new cables and conductors associated with the CREFS, failures that were considered include failure of the cable to short, line to ground, or, line to line, or open circuits on the cables and conductors. No new control cables or conductors were installed for VNPAB.
References (1)
FPL Energy Point Beach, LLC letter to NRC, dated December 8, 2008, License Amendment Request 241, Alternative Source Term (ML083450683)
(2)
NextEra Energy Point Beach, LLC letter to NRC, dated September 4, 2009, License Amendment Request 241, Alternative Source Term, Response to Request for Additional Information (ML092510118)
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ENCLOSURE 2 NEXTERA ENERGY POINT BEACH, LLC POINT BEACH NUCLEAR PLANT, UNITS I AND 2 LICENSE AMENDMENT REQUEST 241 ALTERNATIVE SOURCE TERM REVISION OF PREVIOUS REGULATORY COMMITMENT REGARDING ADMINISTRATIVE CONTROLS FOR CREFS AND VNPAB NextEra Energy Point Beach, LLC (NextEra) determined that a previous Regulatory Commitment made in docketed correspondence regarding the alternative source term (AST) license amendment request (Reference 1) requires revision. The following Regulatory Commitment was contained in NextEra's letter dated February 4, 2010 (Reference 2):
o Administrative controls will be established to ensure that CREFS and the primary auxiliary building ventilation (VNPAB) system will not be in concurrent Technical Specification Action Conditions (TSACs) during planned preventive maintenance activities. These controls will be implemented following NRC approval of LAR 241, no later than the Unit 2 (201 1) refueling outage.
This Regulatory Commitment is revised as follows:
0 Administrative controls will be established to ensure that CREFS and the primary auxiliary building ventilation (VNPAB) system will not be in concurrent Technical Specification Action Conditions (TSACs) during planned preventive maintenance activities on components of the CREFS and VNPAB systems. These administrative controls are not applicable to planned preventive maintenance activities performed on common support system components. These controls will be implemented following NRC approval of LAR 241, no later than the Unit 2 (201 1) refueling outage.
For preventive maintenance activities planned on the CREFS and primary auxiliary building ventilation (VNPAB) systems, administrative controls will be established to prevent concurrent TSACs for these systems under proposed Technical Specification (TS) 3.7.9, CREFS, and TS 3.7.14, VNPAB. These administrative controls are not applicable to planned preventive maintenance activities performed on common support system components. Specifically, for the electrical power supplies common to CREFS and VNPAB fans (e.g., 480 V motor control centers), certain periodic preventive maintenance activities (e.g., bus cleaning and inspection, feeder breaker testing) are performed, which require de-energizing the power supply. These power supply maintenance activities result in a single set of fans from VNPAB and one CREFS fan to be out of service at the same time. In these cases, the CREFS and VNPAB Technical Specification Action Conditions (TSACs) are entered concurrently. These power supply maintenance activities are performed relatively infrequently and for a limited duration. The planned power supply preventive maintenance activities require revision of the Regulatory Commitment above regarding administrative controls to ensure that CREFS and VNPAB systems will not be in concurrent TSACs.
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For these infrequent concurrent CREFS and VNPAB TSACs, the opposite set of fans for each ventilation system would still be operable to perform their required design basis accident function. In addition, as documented in the NextEra Response to Question I in Reference (3), a large break loss-of-coolant accident (LOCA) dose analysis without VNPAB in service was performed utilizing a model of emergency core cooling system (ECCS) leakage based on flashing fractions dependent on containment sump temperature. This analysis demonstrated that the control room dose acceptance criterion of 5 rem TEDE was still met with CREFS in service, but without VNPAB.
References (1)
FPL Energy Point Beach, LLC letter to NRC, dated December 8, 2008, License Amendment Request 241, Alternative Source Term (ML083450683)
(2)
NextEra Energy Point Beach, LLC letter to NRC, dated February 4, 201 0, License Amendment Request 241, Alternative Source Term, Response to Request for Additional lnformation (MLI 00360065)
(3)
NextEra Energy Point Beach, LLC letter to NRC, dated September 3, 2010, License Amendment Request 241, Alternative Source Term, Response to Request for Additional lnformation (MLI 024601 15)
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