ML090620117

Request for Additional Information

ML090620117
Person / Time
Site:	Farley
Issue date:	03/09/2009
From:	Martin R Plant Licensing Branch II
To:	Jerrica Johnson Southern Nuclear Operating Co
Martin R, NRR/DORL, 415-1493
References
TAC MC4684, TAC MC4685
Download: ML090620117 (5)

Text

March 9, 2009 Mr. J. Randy Johnson Vice President - Farley Joseph M. Farley Nuclear Plant 7388 North State Highway 95 Columbia, AL 36319

SUBJECT:

JOSEPH M. FARLEY NUCLEAR PLANT, UNITS 1 AND 2 RE:

REQUEST FOR ADDITIONAL INFORMATION (TAC NOS. MC4684 and MC4685)

Dear Mr. Johnson:

By letters dated February 2, 2008 and April 29, 2008 (Agencywide Documents Access and Management System (ADAMS) Accession Nos. ML0806600657/ ML080660658 (proprietary) and ML081210452), Southern Nuclear Operating Company (SNC) submitted a supplemental response to Generic Letter (GL) 2004-02, Potential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized Water Reactors, for the Joseph M. Farley Nuclear Plant, Units 1 and 2.

The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed SNCs submittals.

The process involved detailed review by a team of approximately 10 subject matter experts, with a focus on the review areas described in the NRCs Content Guide for Generic Letter 2004-02 Supplemental Responses (ADAMS Accession No. ML073110389). Based on these reviews, the staff has determined that additional information is needed in order to conclude there is reasonable assurance that GL 2004-02 has been satisfactorily addressed. The enclosed document describes these requests for additional information (RAIs). The NRC requests that SNC respond to these RAIs within 90 days of the date of this letter. However, we wish to only receive one response letter for all of the RAIs. If SNC concludes that more than 90 days is needed to respond to the RAIs, SNC should request additional time, including a basis for why such time is needed.

Sincerely,

/RA/

Robert E. Martin, Senior Project Manager Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-348 and 50-364

Enclosure:

Request for Additional Information Distribution via Listserv

ML073110389). Based on these reviews, the staff has determined that additional information is needed in order to conclude there is reasonable assurance that GL 2004-02 has been satisfactorily addressed. The enclosed document describes these requests for additional information (RAIs). The NRC requests that SNC respond to these RAIs within 90 days of the date of this letter. However, we wish to only receive one response letter for all of the RAIs. If SNC concludes that more than 90 days is needed to respond to the RAIs, SNC should request additional time, including a basis for why such time is needed.

Sincerely,

/RA/

Robert E. Martin, Senior Project Manager Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-348 and 50-364

Enclosure:

Request for Additional Information Distribution via Listserv DISTRIBUTION:

PUBLIC RidsNrrOd Resource LPL 2-1 RF RidsNrrAdes Resource RidsNrrAdro Resource RidsNrrDorlDpr Resource RidsAcrsAcnw_MailCTR Resource RidsNrrDorlLpl2-1Resource RidsNrrLASRohrer Resource RidsNrrPMRMartin Resource RidsOgcRp Resource MCox, EDO R-II RidsRgn2MailCenter Resource SBurnell, OPA RidsSecyMailCenter Resource Accession Nos.: ML090620117 NRR 106 OFFICE NRR/LPL2-1/PM NRR/LPL2-1/LA NRR/DSS/SSIB NRR/LPL2-1/BC NAME RMartin SRohrer DHarrison MWong DATE 03/5/09 03/4/09 03/5/09 03/9/09 ENCLOSURE FARLEY NUCLEAR PLANT UNITS 1 AND 2 GSI-191/GL 2004-02 REQUEST FOR ADDITIONAL INFORMATION DOCKET NOS. 50-348 AND 50-364 Head Loss and Vortexing:

1.

Provide verification that bore holes were not present in the debris bed during testing. Provide the method used to determine this was the case (e.g., were flows sweeps at the end of testing used for such a determination?).

2.

State whether the test results were extrapolated to different flow velocities. If extrapolation of flow was used explain why it is conservative or prototypical.

3.

Provide verification that the fibrous size distribution used during testing was prototypical or conservative compared to the size distribution predicted by the transport evaluation. (All fiber used in strainer head loss testing should have been prepared as fines.)

4.

Provide details of the debris addition procedures used. Include a description of fibrous concentration during debris addition and the method of adding fibrous debris to the test tank. Provide verification that the debris introduction processes did not result in non-prototypical settling or agglomeration of debris.

5.

Not used.

6.

Provide the amount of each type of debris added to each test.

7.

Provide the area of the test strainer for each test.

8.

Provide the test termination criteria and the methodology by which the final head loss values were extrapolated to the emergency core cooling system mission time or some predicted steady state value. Provide enough test data that the extrapolation results can be verified.

9.

Provide the quantitative margin to flashing through the strainer and describe the methodology used to determine this margin.

10.

Provide the minimum strainer submergence at the onset of recirculation considering both the small-and large-break loss of coolant cases. Provide a vortexing and air entrainment evaluation for the case at the minimum submergence. In general, the small-break loss of coolant accident provides the limiting submergence and this occurs at the onset of low head safety injection recirculation while the containment spray pumps are still supplied by the refueling water storage tank. Limiting pool level is determined by the minimum reactor coolant system contribution to the pool and the refueling water storage tank volume injected at the time that the low level alarm occurs (alerting the operator to align the residual heat removal pumps to recirculation).

11.

Provide an explanation of the difference between the head loss shown in Figure 3.f.13-1, typical head loss plot for test 2M-CS-U2B-40H, and the head loss provided in Figure 3.f.10-1.

12.

Provide an explanation for the behavior of the head loss shown in Figure 3.f.13-1, typical head loss plot for test 2M-CS-U2B-40H, especially at the end after the test termination criteria have been met, water level is being lowered, and head loss increases significantly.

Coatings:

13.

The supplemental response states on page 53 that the transport fraction for qualified coatings is 100 percent. However, on page 29, Table 3e-1 indicates that for the 4D ZOI failed coatings modeled as chips, a transport fraction less than one is assumed. Please clarify this apparent contradiction and describe the methodology and technical basis for the reduction in debris transport if a transport fraction less than one is assumed for the failed coating chips. If test data was used as part of the basis for the transport reduction, please compare the properties of the failed coatings at Farley Nuclear Plant (FNP) to the coating chips that were used for the transport testing.

14.

Please provide the amounts of qualified and unqualified coatings assumed to fail as chips and the amounts of qualified and unqualified coatings assumed to fail as particulate that were used in the strainer qualification tests. If chips were used in testing, then please justify treating qualified and unqualified coating debris as chips, given that page 37 of the supplemental response indicates that a thin bed is expected to be formed during strainer operation. From the NRC review guidance and safety evaluation, if there is a thin bed present, all coating debris should be treated as particulate that would transport to the sump, unless proper justification and/or data are provided. Proper justification for the treatment of coatings as chips could be provided by verifying that testing has shown that the coatings will fail in a manner that their properties match the surrogates used in testing or justifying that a filtering bed would not actually cover the plant strainer.

Debris Source Term:

15.

How will your containment cleanliness and foreign material exclusion programs assure that latent debris in containment will be controlled and monitored to be maintained below the amounts and characterization assumed in the emergency core cooling system strainer design? Will latent debris sampling become an ongoing program?

Chemical Effects:

16.

The value given for the mass of aluminum oxyhydroxide in your April 29, 2008 letter (page 5 of 11) is 988 lbs, but the mass stated in your February 28, 2008, letter (page 88 of 101) is 729 lbs. Please explain the discrepancy in these values and identify which amount of aluminum oxyhydroxide was used as a basis for the chemical effects head loss testing. If less than the predicted amount of chemical precipitate was used in head loss testing, discuss how this affects the interpretation of the test results.

17.

The WCAP-16530-NP chemical spreadsheet predictions show most of the FNP plant-specific precipitate is aluminum oxyhydroxide. Your April 29, 2008 letter provides the one-hour precipitate settlement data for calcium phosphate and sodium aluminum silicate. Please provide the one-hour precipitate settlement data for the aluminum oxyhydroxide precipitate used in head loss testing.

18.

Based on bench testing performed at Alion Science and Technology, FNP assumes aluminum-based precipitates will not form at temperatures above 140°F. Please provide the experimental data that supports that assumption.

Licensing Basis:

19.

Please provide a general description and schedule of the changes to the plant licensing basis that were made as a result of the evaluations and plant modifications made to resolve GSI-191 for FNP.