ML11252A901

Request for Additional Information, Steam Generator Water Level High-High Setpoint Change Technical Specification Table 3.3.2.1 Technical Specifications Task Force-493-A

ML11252A901
Person / Time
Site:	Vogtle
Issue date:	09/21/2011
From:	Patrick Boyle Plant Licensing Branch II
To:	Ajluni M Southern Nuclear Operating Co
Boyle P, NRR/DORLl/LPL2-1, 415-3936
References
TAC ME5778, TAC ME5779
Download: ML11252A901 (3)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555*0001 September 21, 2011 Mr. M. J. Ajluni Nuclear Licensing Director Southern Nuclear Operating Company, Inc.

40 Inverness Center Parkway Post Office Box 1295, Bin - 038 Birmingham, AL 35201-1295 SLlB"IECT: VOGTLE ELECTRIC GENERATING PLANT, UNITS 1 AND 2 - REQUEST FOR ADDITIONAL INFORMATION (RAI), STEAM GENERATOR (SG) WATER LEVEL HIGH-HIGH SETPOINT CHANGE TECHNICAL SPECIFICATION (TS)

TABLE 3.3.2.1, TECHNICAL SPECIFICATIONS TASK FORCE-493-A (TAC NOS. ME5778 AND ME5779)

Dear Mr. Ajluni:

By letter dated March 3, 2011 (Agencywide Documents Access and Management System Accession No. ML110660458), Southern Nuclear Operating Company, Inc., submitted a license amendment request to change the TSs for Vogtle Electric Generating Plant (Vogtle), Units 1 and 2. The amendment would revise a nonconservative error discovered in the Engineered Safety Feature Permissive P-14, SG Water Level High-High instrument setpoint and associated allowable value. The proposed change will also resolve operability determination issues associated with potentially nonconservative TS Allowable Values. This TS change incorporates the corrected nominal trip setpoint and allowable value in TS Table 3.3.2.1, "Engineered Safety Feature Actuation System Instrumentation," for Function 5c, SG Water Level High-High.

Responses to the enclosed RAI are needed for us to continue our review.

Please provide a response within thirty (30) calendar days of the date of this letter.

Sincerely, Patrick G. Boyle, Project Manager Plant Licensing Branch 11-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-424 and 50-425

Enclosure:

RAI cc w/encl: Distribution via Listserv

REQUEST FOR SUPPLEMENTAL ADDITIONAL INFORMATION LICENSE AMENDMENT REQUEST TO REVISE STEAM GENERATOR (SG) WATER LEVEL HIGH-HIGH SETPOINT CHANGE - TECHNICAL SPECIFCATION (TS) TABLE 3.3.2.1 VOGTLE ELECTRIC GENERATING PLANT (VOGTLE), UNITS 1 AND 2 DOCKET NOS. 50-424 AND 50-425 TAC NOS. ME5778 AND ME5779 The Nuclear Regulatory Commission (NRC) staff has reviewed the additional information provided by Southern Nuclear Operating Company, Inc. (SNC, the licensee), for Vogtle Units 1 and 2, in its letter dated August 12, 2011 (Agencywide Documents Access and Management System (ADAMS) Accession Number ML11228A119). Upon review of the correspondence the NRC staff has determined that additional information is needed to complete the review, as follows:

1. The response to question 3(b) provided in the initial request for additional information (RAI)

(ADAMS Accession No. ML11228A119) showed the data and analysis used to establish that tolerance limits for the rack calibration and rack drift of the channel. Similarly response 3(a) explained how the source data for the process measurement accuracy term was grouped.

However, these responses did not describe this information for the other terms in Table 1 of Enclosure 6 of the License Amendment Request (LAR) dated March 3, 2011 (ADAMS Accession No. ML110660458). Provide information on how the error estimate tolerance limits for the following terms (from Table 1 of Enclosure 6 to the LAR) and provide a 95-percent confidence that the interval contains 95 percent of the population.

a. Primary element accuracy

b. Sensor calibration accuracy

c. Sensor reference accuracy

d. Measurement and test equipment accuracy

e. Sensor pressure effects

f. Sensor pressure effects bias

g. Sensor temperature effects

h. Sensor drift

i. Sensor drift bias

2. In enclosure 2 to the RAI response dated August 12, 2011 (ADAMS Accession No. ML11228A119), SNC provided a copy of NMP-ES-033-006, "Vogtle Setpoint Uncertainty Methodology and Scaling Instructions." In the LAR (ADAMS Accession No. ML110660458),

SNC stated that this calculation is used to determine the as-found and the as-left tolerances of the Permissive P-14, Steam Generator Water Level High-High instrument setpoint. This setpoint instruction states that because every loop differs by the design or components, the equation to calculate the channel statistical allowance is customized per the design and components of the loop. Please clarify if the setpoint methodology included in the LAR was performed in accordance with NMP-ES-033-006, and the calculation provided in the LAR will be part of the records controlled under NMP-ES-033-006.

Enclosure

'.. ML11252A901 *via memo dated 8/30/11 OFFICE NRRlLPL2-1/PM NRRlLPL2-1/LA NRRlEICB/BC NRRlLPL2-1/BC NRRlLPL2-1/PM NAME PBoyle MOBrien GWilson* GKulesa PBoyle DATE 9119/11 9/19/11 08/30/11 9121111 9/21/11