ML052420518

License Amendment, Amd MC7612, Equation for Over-Temperature Delta T Function Allowable Value

ML052420518
Person / Time
Site:	North Anna
Issue date:	10/25/2005
From:	Stephen Monarque NRC/NRR/DLPM/LPD2
To:	Christian D Virginia Electric & Power Co (VEPCO)
Monarque, S R, NRR/DLPM, 415-1544
Shared Package
ML052420536	List: ML052420518 ML052990085
References
TAC MC7612, TAC MC7613
Download: ML052420518 (12)

Text

October 25, 2005 Mr. David A. Christian Senior Vice President and Chief Nuclear Officer Virginia Electric and Power Company 5000 Dominion Blvd.

Glen Allen, Virginia 23060

SUBJECT:

NORTH ANNA POWER STATION, UNITS 1 AND 2 - ISSUANCE OF AMENDMENTS ON CORRECTION TO EQUATION FOR OVER-TEMPERATURE DELTA T (OTT) FUNCTION ALLOWABLE VALUE (TAC NOS. MC7612 AND MC7613)

Dear Mr. Christian:

The Commission has issued the enclosed Amendment Nos. 245 and 226 to Renewed Facility Operating License Nos. NPF-4 and NPF-7 for the North Anna Power Station, Units 1 and 2, respectively. The amendments change the Technical Specifications in response to your letter dated July 14, 2005.

These amendments will correct two errors in the units of measure used to determine the OTT Function Allowable Value for North Anna, Units 1 and 2.

A copy of the Safety Evaluation is also enclosed. The Notice of Issuance will be included in the Commission's biweekly Federal Register notice.

Sincerely,

/RA/

Stephen R. Monarque, Project Manager, Section 1 Project Directorate II Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-338 and 50-339

Enclosures:

1. Amendment No. 245 to NPF-4

2. Amendment No. 226 to NPF-7

3. Safety Evaluation cc w/encls: See next page

ML052420518 NRR-058 OFFICE PM:PDII/S1 LA:PDII SRXB/SC OGC SC:PDII/S1 NAME SMonarque CHawes JNakoski MBupp EMarinos DATE 10/13/05 8/25/05 8/10/2005 10/19/05 10/25/05 VIRGINIA ELECTRIC AND POWER COMPANY DOCKET NO. 50-338 NORTH ANNA POWER STATION, UNIT 1 AMENDMENT TO RENEWED FACILITY OPERATING LICENSE Amendment No. 245 Renewed License No. NPF-4

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

A. The application for amendment by Virginia Electric and Power Company et al.,

(the licensee) dated July 14, 2005, 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.

2. Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment, and paragraph 2.C.(2) of Renewed Facility Operating License No. NPF-4 is hereby amended to read as follows:

(2) Technical Specifications The Technical Specifications contained in Appendix A, as revised through Amendment No. 245, are hereby incorporated in the license. The licensee shall operate the facility in accordance with the Technical Specifications.

3. This license amendment is effective as of its date of issuance and shall be implemented within 30 days of issuance.

FOR THE NUCLEAR REGULATORY COMMISSION

/RA/

Evangelos C. Marinos, Chief, Section 1 Project Directorate II Division of Licensing Project Management Office of Nuclear Reactor Regulation

Attachment:

Changes to the Technical Specifications Date of Issuance: October 25, 2005

VIRGINIA ELECTRIC AND POWER COMPANY DOCKET NO. 50-339 NORTH ANNA POWER STATION, UNIT 2 AMENDMENT TO RENEWED FACILITY OPERATING LICENSE Amendment No. 226 Renewed License No. NPF-7

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

A. The application for amendment by Virginia Electric and Power Company et al.,

(the licensee) dated July 14, 2005, 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.

2. Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment, and paragraph 2.C.(2) of Renewed Facility Operating License No. NPF-7 is hereby amended to read as follows:

(2) Technical Specifications The Technical Specifications contained in Appendix A, as revised through Amendment No. 226, are hereby incorporated in the license. The licensee shall operate the facility in accordance with the Technical Specifications.

3. This license amendment is effective as of its date of issuance and shall be implemented within 30 days from the date of issuance.

FOR THE NUCLEAR REGULATORY COMMISSION

/RA/

Evangelos C. Marinos, Chief, Section 1 Project Directorate II Division of Licensing Project Management Office of Nuclear Reactor Regulation

Attachment:

Changes to the Technical Specifications Date of Issuance: October 25, 2005

ATTACHMENT TO LICENSE AMENDMENT NO. 245 TO RENEWED FACILITY OPERATING LICENSE NO. NPF-4 AND LICENSE AMENDMENT NO. 226 TO RENEWED FACILITY OPERATING LICENSE NO. NPF-7 DOCKET NOS. 50-338 AND 50-339 Replace the following page of the Appendix "A" Technical Specification with the enclosed page as indicated. The revised page is identified by amendment number and contain vertical lines indicating the areas of change.

Remove Page Insert Page 3.3.1-16 3.3.1-16

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 245 TO RENEWED FACILITY OPERATING LICENSE NO. NPF-4 AND AMENDMENT NO. 226 TO RENEWED FACILITY OPERATING LICENSE NO. NPF-7 VIRGINIA ELECTRIC AND POWER COMPANY NORTH ANNA POWER STATION, UNITS 1 AND 2 DOCKET NOS. 50-338 AND 50-339

1.0 INTRODUCTION

By letter dated July 14, 2005 (Reference 1), Virginia Electric and Power Company (the licensee) submitted an amendment request for North Anna Power Station, Units 1 and 2 to revise Note 1 of Technical Specification (TS) Table 3.3.1-1, Reactor Trip Instrumentation to correct two errors in the units of measure of the constants in the axial power distribution (f 1(l)) equation.

The f1(I) reset function is a part of the Overtemperature Delta T (OTT) reactor trip function used to adjust the T setpoint to account for the axial power distribution imbalance.

2.0 REGULATORY EVALUATION

The Nuclear Regulatory Commission (NRC) staff has identified the applicable regulatory requirements that the NRC staff considered in its review of the application. These requirements are listed below.

Appendix A to Title 10 of the Code of Federal Regulations (10 CFR) Part 50, General Design Criterion (GDC)-20 requires the reactor protection system to be designed to initiate automatically the operation of appropriate systems to assure that specified acceptable fuel design limits (SAFDL) are not exceeded as a result of anticipated operational occurrences (AOO).

10 CFR 50.36 (c)(2)(ii), Criterion 3, requires a limiting condition for operation (LCO) be established for a structure, system, or component that is part of the primary success path and which functions or actuates to mitigate a design basis accident or transient. The OTT reactor trip function initiates a unit shutdown, based on the measured temperature difference (T) across the core, to protect against violating the SAFDL of departure from nucleate boiling ratio (DNBR) during AOOs. As such, a LCO must be established for the OTT function. TS LCO 3.3.1 specifies that the reactor trip system instrumentation for each function in TS Table 3.3.1-1 shall be operable. TS Table 3.3.1-1 specifies the allowable values and trip setpoints of the reactor trip functions, including the OTT function.

To ensure continued compliance with GDC-20 and 10 CFR 50.36(c)(2)(ii), Criterion 3, the NRC staff evaluation of the proposed change to the f1(I) equation is based on its effect on the allowable value of the OTT function.

3.0 TECHNICAL EVALUATION

The OTT trip function, as described in Note 1 of TS Table 3.3.1-1, is provided to ensure that the design limit DNBR is met. The OTT trip function uses each reactor coolant loops T as a measure of reactor power and is compared with the calculated T setpoint. The T setpoint is based on the T across the core at 100 percent rated thermal power (RTP), and is varied and calculated with the following parameters: pressurizer pressure, reactor coolant temperature, and axial neutron flux difference (I).

The T reset function, f1(I), is used in the OTT trip function to account for imbalances in the axial power distribution as detected by the nuclear instrumentation system (NIS) upper and lower power range detectors. The reset function f 1(I) is generally defined as:

f1(I) = m1 (d1 - I) when I < d1

=0 when d1 # I # d2

= m2 (I - d2 ) when d2 < I Where I is the axial flux difference defined as I = qt - qb; qt and qb are % RTP of the neutron powers of the top half and bottom half of the core, respectively; d1 and d2 are the negative and positive break points of I deadband in % RTP; and m1 and m2 are the absolute values of negative and positive slopes of the f 1(I) function. If I is within the design limit, or predefined deadband [d1,d2], no adjustment for the T setpoint is necessary, and the reset function f 1(I) is equal to 0. If I is outside of the deadband, i.e., I < d1 or I > d2, then the T setpoint is reduced in accordance with the reset function f 1(I).

In the North Anna TS, the constants in the f1(I) reset function, as well as other constants in the OTT trip function, have been relocated to the Core Operating Limits Report (COLR). In Note 1 of TS Table 3.3.1-1, the f1(I) for the OTT function is defined as:

f1(I) = [*] {[*]% - (qt - qb)} when qt - qb < [*]% RTP 0% of RTP when [*]% RTP # qt - qb #[*]% RTP

[*]{(qt - qb) - [*]} when qt - qb > [*]% RTP Where qt and q b are percent RTP in the upper and lower halves of the core, respectively, and qt + qb is the total thermal power in percent RTP. The values denoted with [*] are the values of the I deadband break points and slopes of the reset function, respectively, specified in the COLR.

The licensee discovered that the units of measure in the first two expressions of the f 1(I) equation are in error. The % and % of RTP in the first and second expressions of the f 1(I) equation, respectively, should not be included because f 1(I) is a dimensionless quantity. The proposed change would delete the % and % of RTP from the equation, and the revised f 1(I) for the OTT function in the Note 1 of TS Table 3.3.1-1 would become:

f1(I) = [*] {[*] - (qt - qb)} when qt - qb < [*]% RTP 0 when [*]% RTP # qt - qb #[*]% RTP

[*]{(qt - qb) - [*]} when qt - qb > [*]% RTP The revised equation is consistent with the equation for f1(I) specified in the original North Anna TS, and the COLRs for North Anna, Units 1 and 2 (References 2 and 3). The NRC staff considers the proposed change as being an administrative error correction. The correction of the errors in the units of measure of the T reset function f1(I) does not involve any change to allowable value or trip setpoint of the OTT trip function. Therefore, with these error corrections, the OTT function continues to comply with GDC-20 and 10 CFR 50.36, Criterion

3. The NRC staff concludes that the proposed change is acceptable.

4.0 STATE CONSULTATION

In accordance with the Commissions regulations, the Virginia State official was notified of the proposed issuance of the amendment. The state official had no comments.

5.0 ENVIRONMENTAL CONSIDERATION

These amendments change a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. The NRC staff has determined that the amendments involve 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 (70 FR 48208). Accordingly, the amendments meet 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, based on 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 Commissions regulations, and (3) the issuance of the amendments will not be inimical to the common defense and security or to the health and safety of the public.

7.0 REFERENCES

1. Letter from Leslie N. Hartz, VEPCO, to US Nuclear Regulatory Commission, Virginia Electric and Power Company, North Anna Power Station Units 1 and 2, Proposed Technical Specification Changes, Correction to Equation for OTT Function Allowable Value, July 14, 2005,05-420. ADAMS Accession No. ML051960435

2. Letter from C. L. Funderburk, Dominion Resources Services, Inc, to US Nuclear Regulatory Commission, Virginia Electric and Power Company, North Anna Power Station Unit 1, Core Operating Limits Report, October 11, 2004,04-619. ADAMS Accession No. ML042940288

3. Letter from C. L. Funderburk, Dominion Resources Services, Inc, to US Nuclear Regulatory Commission, Virginia Electric and Power Company (Dominion), North Anna Power Station Unit 2, Core Operating Limits Report, June 2, 2004,04-328. ADAMS Accession No. ML041560086 Principal Contributors: Y. Hsii Date: October 25, 2005

North Anna Power Station, Units 1 & 2 cc:

Mr. C. Lee Lintecum Mr. Jack M. Davis County Administrator Site Vice President Louisa County North Anna Power Station Post Office Box 160 Virginia Electric and Power Company Louisa, Virginia 23093 Post Office Box 402 Mineral, Virginia 23117-0402 Ms. Lillian M. Cuoco, Esq.

Senior Counsel Dr. Robert B. Stroube, MD, MPH Dominion Resources Services, Inc. State Health Commissioner Building 475, 5 th floor Office of the Commissioner Rope Ferry Road Virginia Department of Health Waterford, Connecticut 06385 Post Office Box 2448 Richmond, Virginia 23218 Dr. W. T. Lough Virginia State Corporation Commission Division of Energy Regulation Post Office Box 1197 Richmond, Virginia 23218 Old Dominion Electric Cooperative 4201 Dominion Blvd.

Glen Allen, Virginia 23060 Mr. Chris L. Funderburk, Director Nuclear Licensing & Operations Support Dominion Resources Services, Inc.

Innsbrook Technical Center 5000 Dominion Blvd.

Glen Allen, Virginia 23060-6711 Office of the Attorney General Commonwealth of Virginia 900 East Main Street Richmond, Virginia 23219 Senior Resident Inspector North Anna Power Station U. S. Nuclear Regulatory Commission 1024 Haley Drive Mineral, Virginia 23117