ML092020265
| ML092020265 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 07/31/2009 |
| From: | Beltz T Plant Licensing Branch III |
| To: | |
| beltz T, NRR/DORL/LPL3-1, 301-415-3049 | |
| Shared Package | |
| ML092110112 | List: |
| References | |
| GL-04-002, TAC MC4679, TAC MC4680 | |
| Download: ML092020265 (6) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 July 31, 2009 LICENSEE:
Indiana Michigan Power Company FACILITY:
Donald C. Cook (D.C. Cook) Nuclear Plant, Units 1 and 2
SUBJECT:
SUMMARY
OF JULY 20,2009, CATEGORY 1 PUBLIC MEETING VIA TELECONFERENCE TO DISCUSS GENERIC LETTER 2004-02 REQUESTS FOR ADDITIONAL INFORMATION (TAC NOS. MC4679 AND MC4680)
On July 20, 2009, a Category 1 public meeting was held via teleconference between representatives of Indiana Michigan Power Company (the licensee) and the U.S. Nuclear Regulatory Commission (NRC) staff from NRC Headquarters, One White Flint North, 11555 Rockville Pike, Rockville, Maryland. The purpose of the meeting was to provide the staff an opportunity to respond to any final questions that the licensee may have related to the requests for additional information (RAI) associated with Generic Letter (GL) 2004-02 Agencywide Documents Access and Management System (ADAMS) Accession No. ML091490421).
A list of attendees is provided in Enclosure 1.
The meeting offered an opportunity to resolve any outstanding concerns related to the licensee's future response to the GL 2004-02 RAls. The NRC staff addressed eight issues, four of a general nature, and four specifically related to the issued RAls. The questions and responses are provided in the paragraphs below.
The staff addressed the following general questions requested from the licensee.
- 1. What reviews and considerations have been given to D.C Cook's use of the Section 6 methodology?
Response: The staff reviewed the information provided in the D.C. Cook supplemental responses concerning the Section 6 methodology (e.g., pages 7 and 8 of Attachment 3 to the February 29, 2008, supplemental response, as well as discussion of the specific analysis provided in various technical areas for the debris generation break size cases in the same document).
In both the supplemental response and during an April 16, 2009, public meeting, the information provided concerning the alternate methodology (i.e., the specific discussion of the separate Region I and Region II methodologies in the relevant technical areas) was not sufficient for the staff to conclude that the proposed RAls were either (1) not necessary, or (2) only applicable to either the Region I or Region II analysis. It appeared to the staff that similar or identical approaches were typically credited by the licensee for both the Region I and Region II analysis, and that the proposed RAls were appropriate for both.
One notable difference is the brief description of post-LOCA [loss-of-coolant accident]
operator actions mentioned on pages 7 and 8 that could be applied to the mitigation of
- 2 Region II breaks. However, (1) it was not clear that this approach was credited by the licensee as a primary success path for these breaks; (2) the level of detail was limited; and (3) it was not clear that the benefit obtained from the operator action was sufficient to obviate the proposed RAls.
- 2. What reviews have been done to assess the overall level of conservatism of our submittal?
Response: The staff determined in 2008 that attempts to reach conclusions of overall adequacy based on licensee assertions of conservatisms will only be successful when a relatively small number of RAls are outstanding. This is particularly the case for plants with RAls related to sump head loss testing and evaluation methodology.
Large numbers of such RAls imply uncertainties in whether the overall test results are conservative. As a hypothetical example, we know of no valid way to balance 20 conservatisms against 20 potential non-conservatisms. GSI-191 has demonstrated that a small change in the amount, type, or order of arrival of debris that reaches a sump strainer can lead to very large differences in head loss. The staff's position is that a conservative or prototypical head loss test is necessary unless a licensee can show significant non-filtering strainer area.
The licensee responded by asking if the above statement that "the staff's position is that a conservative or prototypical head loss test is necessary unless a licensee can show significant non-filtering strainer area" implied that additional head loss testing was required to address the RAls. The staff stated that there was some potential skepticism without another test being performed.
The staff further noted that starting last year, all licensee response packages were screened to determine whether there was any reasonable probability of success before sending them to the Integration Review Team (IRT) that assesses overall "holistic" compliance even in the presence of uncertainties. D.C. Cook and many others were screened out on this basis prior to issuance of the draft RAls. After the April 2009, public meeting, management asked the key staff reviewers, including some potentiallRT staff members, to review the information presented by the licensee at that time to consider again whether an IRT was appropriate. The staff's decision was that sufficient uncertainties remained such that an IRT review would not be fruitful. The path forward with D.C. Cook, as with many others, is to get the number of uncertainties and potential non-conservatisms down to a manageable number. This will provide increased confidence that the conservatisms as stated by the licensee overwhelm the remaining potential non-conservatisms that then go to IRT.
- 3. What areas present the greatest level of concern for the staff (i.e., are there areas that appear difficult to come to resolution)?
Response: One member of the technical staff noted that the debris transport RAls related to the distribution of debris on the strainer modules (Questions 6 and 7) were the most significant RAls in his technical areas of characteristics, transport, and net positive suction head (NPSH).
-3 The staff also identified areas of concern associated with the test methodology, as well as how the strainer was modeled (main and remote) regarding debris loading. The test methodology was not shown to be prototypical or conservative. The licensee also used a bump-up factor for the chemical test which has not been adequately justified, although the method appears to be better than VUEZ. The RAls of concern specifically related to these issues are Questions 10-13, 15, and 16.
- 4. What is the staffs sense of issue resolution (Le., is it converging to resolution)?
Response: Given the numbers of RAls outstanding at this time, and the response to Question 2 above, the staff cannot conclude convergence, nor does it have reason to conclude that there is divergence.
The staff has a process intended to drive toward convergence (i.e., agreement between staff and the licensee on what the licensee needs to do to close G81-191 for D.C. Cook) in the next few weeks.
The staff and licensee also discussed questions/concerns specifically related to the NRC-issued RAls. The questions and responses are provided below.
- 1. Question 7.d - The licensee states that they do not understand the staff's request.
Response: The staff discussed the question with the licensee and appeared to provide adequate clarification.
- 2. Question 11 - The licensee states that the question appears to be additional information that is really part of Question 12, and requires no separate response.
Response: The staff discussed the concern with the licensee and reached the conclusion that Questions 11 and 12 are linked, such that Question 11 can be answered as referenced during the response to Question 12.
- 3. Question 15 - The licensee requests clarification as to what is meant by the statement, "Provide the results of any tests run at 100% flow throughout larger portions of the test."
Response: The licensee informed the staff that there was no test run performed at 100 percent flow. The staff noted the licensee's response.
- 4. Question 21 - The licensee states that they did not understand the statements relative to "scaling back the head loss result" and "discrepancy in flow rate for this test."
Response: The licensee informed the staff that nothing was "scaled back" during testing. The staff noted the licensee's response.
The NRC staff requested that the licensee provide comparison information (e.g., results in tabular form) to assist the staff by providing clarification to better understanding the tests results.
-4 Prior to concluding the teleconference, it was agreed that an additional public meeting was needed to review each licensee RAI response and determine if the proposed response adequately answers the staff's question, or that additional information is still required. This meeting will be held via teleconference from NRC Headquarters on August 12, 2009.
Members of the public were not in attendance at this meeting.
Please direct any inquiries to me at 301-415-3049, or Terry.Beltz@nrc.gov.
~
Terry
. Beltz, Senior Project Manager Plant licensing Branch 111-1 Division of Operating Reactor licensing Office of Nuclear Reactor Regulation Docket Nos. 50-315 and 50-316
Enclosures:
list of Attendees cc w/encls: Distribution via listserv
LIST OF ATTENDEES JULY 20, 2009, TELECONFERENCE WITH INDIANA MICHIGAN POWER COMPANY TO DISCUSS REQUESTS FOR ADDITIONAL INFORMATION ASSOCIATED WITH GENERIC LETTER 2004-02 FOR THE DONALD C. COOK NUCLEAR PLANT, UNITS 1 AND 2 Indiana Michigan Power Company Michael Scott James Petro John Lehning Michael Scarpello Matt Yoder Paul Leonard Steve Smith Kevin O'Connor Terry Beltz William Knous
- Ervin Geiger
- Alion Science & Technology Enclosure
Package: ML092110112 Meeting Notice: ML091880164 M
eetmg Surnmary: ML092020265 OFFICE DORULPL3-1/PM DORULPL3-1/LA DSS/SSIB/BC DORULPL3-1/BC DORULPL3-1/PM NAME TBeitz THarris MScott w/comments LJames TBeitz DATE 07/23/2009 07/23/2009 07/27/2009 07/31/2009 07/31/2009