ML092330062
| ML092330062 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 09/01/2009 |
| From: | Balwant Singal Plant Licensing Branch IV |
| To: | Luminant Generation Co |
| Singal, Balwant K, NRR/DORL 301-415-3016 | |
| References | |
| GL-04-002, TAC MC4676, TAC MC4677 | |
| Download: ML092330062 (7) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 September 1, 2009 LICENSEE:
Luminant Generation Company LLC FACILITY:
Comanche Peak Steam Electric Station, Units 1 and 2
SUBJECT:
SUMMARY
OF AUGUST 10, 2009, CATEGORY 1 MEETING WITH LUMINANT GENERATION COMPANY LLC ON RESOLUTION OF GENERIC LETTER 2004-02 (TAC NOS. MC4676 AND MC4677)
On August 10, 2009, a public meeting was held between the U.S. Nuclear Regulatory Commission (NRC), and representatives of Luminant Generation Company LLC (Luminant, the licensee), at NRC Headquarters, One White Flint North, 11555 Rockville Pike, Rockville, MD from 1:00 p.m. to 3:00 p.m. The purpose of the meeting was to discuss the of resolution the draft NRC request for additional information (RAI) regarding Generic Letter (GL) 2004-02, "Potential Impact of Debris Blockage on Emergency Recirculation during Design Basis Accidents at Pressurized-Water Reactors," for Comanche Peak Steam Electric Station (CPSES), Units 1 and 2. A list of meeting attendees in person or via conference call (NRC staff, Luminant, AREVA NP Inc. (AREVA), Alion Science and Technology Corporation (Alion),
Performance Contracting, Inc. (PCI), and members of the public) is enclosed.
During the meeting, Luminant's proposed responses to RAI Questions 6, 8, 9, 10, 11, 15, 20, and 37 issued on May 11, 2009 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML091660376) were discussed.
Results of Discussion RAI #6 and 8: The NRC staff expressed the view that the issues of the analytically assumed 30-day erosion percentage (RAI #6) and the erosion of fiberglass debris pieces that settled in the head loss test flume (RAI #8) were not adequately addressed during the previous meeting on July 9, 2009. The NRC staff suggested that a sensitivity study, as to the significance of these erosion issues for CPSES, Units 1 and 2, would help put the significance of the issue into perspective. The licensee agreed to follow up with additional information concerning conservatisms in the analysis. The licensee also proposed to submit videos for staff review showing the release of fines from pieces of fibrous insulation added to a test flume. The staff expressed skepticism that these videos would provide quantitative insights that may be needed.
The licensee requested that the NRC staff confirm the process for submitting the videos on docket. Project Manager, Balwant K. Singal, took an action to get back to the licensee after discussing this matter with Agencywide Documents Access and Management System (ADAMS) staff.
RAI #9: Luminant agreed to provide an expanded time line on wash down and pool-fill for small or large pieces of debris. The NRC staff expressed skepticism that the highly variable and chaotic processes that govern non-recirculation transport could be analyzed rigorously and suggested that the licensee instead address the issue by demonstrating that detailed modeling
- 2 of wash down and pool-fill was not necessary, in part, because (1) the transport of fine debris, which is a major contributor to head loss was treated conservatively, (2) the debris interceptor would tend to prevent the transport of larger debris, (3) a penalty of 200 ft2 was assumed for the strainer sacrificial surface area. The licensee agreed to address NRC staff's concerns.
RAI #10 and 11: The licensee agreed to provide information discussed in previous teleconferences with the NRC staff, including contour plots showing turbulent kinetic energy and velocity in the containment pool, and a comparison of these values to the respective values in the test flume. The NRC staff noted that the flow conditions in the test flume appear less conducive to debris transport than the corresponding plant condition. However, based on information from the licensee about plant-specific conservatisms associated with the CPSES, Units 1 and 2 analysis, including the use of two-train test flow rates for a head loss case that assumed all of the debris on a single strainer, the NRC staff indicated that the mClgnitude of the non-conservatism would likely not result in the test being considered unacceptable for CPSES, Units 1 and 2.
RAI #15: The NRC staff expressed concern that addition of fiber prior to the starting of the test pump resulted in a non-prototypically low head loss due to (1) a non-prototypical reduction in the transport of the latent fiber to the strainer and (2) a non-prototypical reduction in head loss due to the addition sequence of adding fibrous debris prior to particulate debris. The licensee offered to provide a video that demonstrates that latent fiber will transport under flow conditions representative of the CPSES, Units 1 and 2, test conditions. The licensee further stated that debris is expected to arrive at the strainer homogenously, rather than in a prescribed sequence.
The NRC staff noted that adding fiber prior to particulate has been shown to lead to the lowest head loss of any debris addition sequence (Le., heterogeneous or homogeneous). The licensee noted that other conservatism in the analysis offsets this condition and agreed to provide additional information to justify this view.
RAI #20: The NRC staff expressed concern that the transport of large debris in the test flume was inhibited by the narrowness of the flume. The licensee stated that debris pieces smaller than the large piece size category in Nuclear Energy Institute (NEI) 04-07 were added to the tests. The NRC staff stated that, in light of the debris interceptors around the strainers, the most significant concern related to this issue is that large pieces of fiber could filter and trap other debris added later, such as chemical precipitates. The NRC staff suggested that the licensee provide evidence that the large pieces of debris settled on the flume floor did not filter out significant quantities of suspended particulate debris or precipitate. The NRC staff requested licensee to provide additional information like porosity and the shape of the debris as evidence in support of the licensee's response.
RAI #37: The licensee did not agree that main steam line break needed to be considered as part of GL 2004-02, since it is not part of design basis for CPSES, Units 1 and 2. The licensee also expressed the view that previous testing performed for this case was adequate to demonstrate acceptable strainer performance. The NRC staff questioned the sufficiency of the licensee's previous testing to demonstrate that the limiting main steam line break case had been adequately addressed. The licensee agreed to provide regulatory and technical justifications to the NRC staff by September 10, 2009, for consideration by the NRC staff. The staff agreed to consider further the regulatory aspects of the licensee's argument.
- 3 The licensee also agreed to provide responses to the RAls by October 13, 2009.
This was a Category 1 meeting. The public was invited to observe and given an opportunity to communicate with the NRC staff after the business portion, but before the meeting was adjourned. Public Meeting Feedback forms were not received.
Please direct any inquiries to me at (301) 415-3016, or Balwant.Singal@nrc.gov.
Sincerely,
£~" )Wq~.~
~"'-~S Balwant K. Singal, Senior Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-445 and 50-446
Enclosure:
List of Attendees cc w/encl: Distribution via Listserv
ENCLOSURE LIST OF MEETING ATTENDEES AND NEI BRIDGE LINE PARTICIPANTS AUGUST 10, 2009, PUBLIC MEETING WITH LUMINANT GENERATION COMPANY LLC
LIST OF ATTENDDES VIA CEONFERENCE CALL FOR AUGUST 10, 2009 PUBLIC MEETING WITH LUMINANT GENERATION COMPANY LLC NAME ORGANIZATION Luminant and Supporting Organizations Tim Hope Luminant Fred Madden Luminant Jimmy Seawright Luminant Charles Feist Luminant Harold Beck AREVA Chris Kudla PCI Jim Bleigh PCI Stu Cain ALDEN William Knous ALiON Gilbert Zigler ALiON Tim Sande ALiON Members of the Public Fred Emerson GE Ron Holloway Wolf Creek Nuclear Operating Corporation Hiroshi Mirsuoka Mitsubishi John Buttler NEI
LIST OF ATTENDEES IN PERSON FOR AUGUST 10, 2009 PUBLIC MEETING WITH LUMINANT GENERATION COMPANY LLC NAME ORGANIZATION Balwant K. Singal DORLlNRR Weidong Wang ACRS/NRC John Lehning SSIB/NRR Michael Scott SSIB/NRR
- 3 This was a Category 1 meeting. The public was invited to observe and given an opportunity to communicate with the NRC staff after the business portion, but before the meeting was adjourned. Public Meeting Feedback forms were not received.
Please direct any inquiries to me at (301) 415-3016, or Balwant.Singal@nrc.gov.
Sincerely, IRA!
Balwant K. Singal, Senior Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-445 and 50-446
Enclosure:
List of Attendees cc w/encl: Distribution via Listserv DISTRIBUTION:
PUBLIC RidsNrrDorlLpl4 Resource RidsRgn4MailCenter Resource LPLIV rtf RidsNrrDrpPgcb Resource CTucci, NRR RidsAcrsAcnw_MailCTR RidsNrrDssSsib Resource LTrocine, EDO Region IV Resource RidsNrrPMWolfCreek Resource SSmith, NRRtSSIB RidsNroDsraSpcv Resource RidsNrrLAJBurkhardt Resource JLehning, NRRtSSIB RidsNrrDciCsgb Resource RidsOgcRp Resource A AMSAccesslon No.ML09 330062
- emals rom M 5 cott and J Leh' d t D
2 "I f mng aed 8/17/09 OFFICE NRRlLPL4/PM BSingal 8/20/09 NAME DATE NRR/LPL4/LA NRR/SSIB/BC NRR/LPL4/BC NRR/LPL4/PM JBurkhardt SLittie for MScott*
MMarkley BSingal 8/30/09 8/17/09 9/1/09 9/1/09 OFFICIAL RECORD COpy