ML083570609

E-mail Point Beach - Draft Request for Additional Information for LAR-258, LOCA Analysis Using Astrum

ML083570609
Person / Time
Site:	Point Beach
Issue date:	12/22/2008
From:	Justin Poole Plant Licensing Branch III
To:	Jim Costedio Florida Power & Light Energy Point Beach
References
LAR-258
Download: ML083570609 (2)

Text

From: Justin Poole Sent: Monday, December 22, 2008 3:29 PM To: 'james.costedio@fpl.com'

Subject:

DRAFT - Point Beach RAIs for LAR 258 - DRAFT

Jim, The staff has come up with some RAI questions for the LOCA analysis using ASTRUM amendment. Please review these and let me know if you have any questions on these that you would like to discuss with the staff. If so, we will have a phone call with the staff to address your questions and a final and formal version of the RAIs will be issued. Please let me know if you have any questions. Thanks.

Justin C. Poole Project Manager NRR/DORL/LPL3-1 U.S. Nuclear Regulatory Commission (301)415-2048 email: Justin.Poole@nrc.gov

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

DRAFT

1) Compared to the current licensing basis, large-break loss of coolant accident (LOCA) results (Obtained from a 2007 revision of the Point Beach UFSAR), the limiting units best-estimate 95th percentile peak cladding temperature (PCT) is reduced by approximately 150°F. This result prompts two conclusions on the part of the staff: (1)

That the power uprate case is not bounding of the current licensed thermal power case, as shown by a lower PCT, or (2) that the change in statistical sampling has redefined uncertainties in such a manner that the changes in safety margin resulting from the power uprate are masked by the method implementation. Provide information to quantify:

(A) The PCT/MLO trend associated with the power uprate:

Compare the results of several nominal (i.e., cases whose PCTs approach the 50th percentile) Point Beach WCOBRA/TRAC runs assuming the implementation of an EPU to cases assuming the current licensed thermal power level holding other parametric assumptions the same.

(B) The PCT/MLO trend associated with changing from CQD to ASTRUM:

Compare generic results for PCT and MLO for plants that have implemented a CQD/ASTRUM change without significant accompanying changes in plant parameters. Include central indicators and bounding values.

2) Page 1 of Enclosure 1 to the license amendment request mentions rackup items.

Please define this term, list the items, and provide a disposition relative to the ASTRUM analysis.

3) Figures 13 and 15 bear different titles but appear to show the same information. Please explain.

4) Figure 13 presents the average channel collapsed liquid level from the limiting PCT case. Four hundred twenty to 500 seconds following the break, the oscillations in collapsed liquid level become quite severe. Please evaluate the result and explain the phenomenon. Also provide graphs from other cases in the 420-500 second time range to show whether these oscillations are anomalous for the limiting case.

5) Provide reference linear heat rates assumed in the analyses: average, peak, hot rod average, hot assembly average, and hot assembly peak.

6) The assumed amount of steam generator tube plugging has changed in an apparently non-conservative direction. Please explain.

DRAFT E-mail Properties Mail Envelope Properties ()

Subject:

DRAFT - Point Beach RAIs for LAR 258 - DRAFT Sent Date: 12/22/2008 3:06:17 PM Received Date: 12/22/2008 3:28:00 PM From: Justin Poole Created By: Justin.Poole@nrc.gov Recipients:

james.costedio@fpl.com ('james.costedio@fpl.com')

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