ML080880010
| ML080880010 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 03/27/2008 |
| From: | Markley M NRC/NRR/ADRO/DORL/LPLIV |
| To: | Edwards M, Lippy D, Matthews T Omaha Public Power District |
| Markley, M T, NRR/DORL/LP4, 301-415-5723 | |
| References | |
| TAC MD6204 | |
| Download: ML080880010 (5) | |
Text
From:
Michael Markley To:
DONNA L LIPPY; MICHAEL EDWARDS; THOMAS C MATTHEWS Date:
3/27/2008 11:33:57 AM
Subject:
Requests for Additional Information Tom, Donna, and Mike, Attached are the RAIs for today's telecon. The attached files provide a clarification resulting from feedback from OPPD and revise the issuance to reflect today's date. I will forward the ADAMS accession number(s) as soon as it is available.
Michael Markley Sr. Project Manager Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Phone (301) 415-5723 Facsimile (301) 415-2102 Office: O-8D3 Mail Stop: O-8B1 e-mail: MTM@nrc.gov CC:
Glenna Lappert FORT CALHOUN STATION SECOND REQUEST FOR ADDITIONAL INFORMATION LICENSE AMENDMENT REQUEST RE: MODIFICATION OF CONTAINMENT SPRAY ACTUATION LOGIC (WATER MANAGEMENT)
Containment Analysis
- 1. July 30, 2007 letter Attachment 3 (a)
In TS 2.4b., please explain the difference between (1)a.i and (1)a.ii and (1)a.i or (1)a.ii. How is this difference made clear to the operators?
(b)
TS 2.4(2)a. discusses two of the components listed in (1)a.i and ii." Should this and also be an or?
- 2. July 30, 2007 letter Attachment 6 FC07247 Section 3.1 The mass and energy release for the short-term containment analysis assumes both low and high constant containment back-pressure. Please explain why a low containment backpressure can yield the limiting peak containment pressure since the reflood rate would be slower for this case.
- 3. July 30, 2007 letter Attachment 6 FC07247 Sections 3.1, 3.3.4.2, 3.5 Please verify and complete the entries in the following table.
Transition (Early:
1000 seconds/Late:
RAS)
Energy Dissipation (Existing/Alternate)
LOCA Peak Containment Pressure N/A. Time to peak pressure is too short.
N/A. Time to peak pressure is too short.
LOCA peak Containment temperature N/A. Time to peak pressure is too short.
N/A. Time to peak pressure is too short.
LOCA Long-term (24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />) Pressure RAS Existing/Alternate LOCA Sump Temperature RAS Existing Peak CCW and RW Temperature RAS
?
- 4. July 30, 2007 letter Attachment 6 FC07247 Section 3.3.4 Section 3.3.4 states that: For the purposes of this assessment, stored energy dissipation was forced to be completely dissipated by 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> (86400 seconds) by increasing the energy dissipation rates, as necessary.
Will this method be used for future calculations? If not, what method for stored energy dissipation will be used?
- 5. July 30, 2007 letter Attachment 6 Section 3.4 Why are the limiting hot leg and cold leg break cases with containment spray necessarily the most limiting without containment spray?
- 6. July 30, 2007 letter Attachment 6 FC07247 Section 3.4 A second CCW pump is started for the case of heat removal by the fan coolers. What is the purpose for starting the second CCW pump, that is, what limit would not be met if the second CCW pump was not started? How is this operator action specified in the emergency operating procedures? What are the consequences if the operator starts the second CCW pump before 30 minutes? After 30 minutes, e.g., after 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />? Not at all? What effect does this have on emergency diesel loading?
- 7. July 30, 2007 letter Attachment 6 FC07247 Section 3.3.4.1 and 3.3.4.2 For the limiting cases of hot leg and cold leg breaks without containment spray, please provide the start time of the containment fan coolers.
- 8. July 30, 2007 letter Attachment 6 FC07247 Section 3.3.4.2
(a) How much heat is required to be removed by the containment air cooling and filtering system (CACFS) to mitigate the consequence of the limiting hot leg and cold leg break LOCAs? How does this compare with the capability of the fan coolers? (b) Discuss any verification of the assumed heat removal rates of the fan coolers with data. (c) What assurance is there in terms of testing and surveillances, that the actual heat removal rates during a LOCA will not be lower than the assumed heat removal rates?
- 9. July 30, 2007, letter Attachment 6 Section 3.6 This section states that The peak component cooling water temperature and the peak raw water temperature are a function of the containment vapor temperature and humidity for the containment air coolers throughout the transient and the sump temperature for the shutdown cooling (SDC) system after RAS.
But the shutdown coolers will not be used during the LOCA. Please explain.
- 10. July 30, 2007 letter Attachment 6 FC07247 Section5 References (a) Please provide Reference 1 or provide a docketed reference. If Reference 1 is the Framatome ANP report BAW-10252(P) submitted to the NRC for approval by letter dated July 13, 2004, what is the relationship between this reference and the licensees January 27, 2003, GOTHIC submittal?, (b) If Reference 1 applies only to peak containment pressure calculations, explain its applicability to the other portions of the present application (long term LOCA, NPSH).
- 11. February 21, 2008 letter Table 1 and Response to Question 2 (a)
The response to Question 2 states that the short term LOCA analysis assumes a surface area of the sump of zero ft2. Table 1 states that the liquid-vapor interface area is maintained consistent with the AOR. Are these consistent?
Why is this conservative?
(b)
What assumption is made about heat transfer from the sump to the containment atmosphere for the long term calculations? Why is this conservative?
- 12. February 21, 2008 letter response to Question 9 (a)
What is the required NPSH of the HPSI pump for comparison with the available NPSH values? What flow rate does the required NPSH correspond to? Why is this flow rate conservative? Does this assume one HPSI pump in operation or more? How does this flow rate compare with the flow rate assumed in the Fort Calhoun 10 CFR 50.46 ECCS analysis?
(b)
The long term containment sump temperature analysis was done with the transition time at RAS and the stored energy dissipation rates calculated using the existing method. This approach, as shown in Figures 11 and 14 of to the July 30, 2007, 2007, letter, yields the lowest sump
temperature. Would NPSH margin exist for the HPSI pumps using the other combinations (early-existing, early-alternative, extended-alternate)?
(c)
The FCS DRAFT response to first round RAI 1 states that the results of this analysis (of available head) will be compared graphically against the NPSH required which will be determined based on the sump temperature and pump flow as a function of time after RAS. Please describe how sump temperature is included in the determination of required NPSH. How is this consistent with the guidance of Regulatory Guide 1.82 Revision 3 Position 1.3.1.5?
- 13. February 21, 2008 letter Response to Question 2 Revaporization is considered for the peak containment pressure calculation (Table 1 of to the February 21, 2008 letter) but is zero for the sump temperature analysis (Page 5 of Attachment 1, Item 5). Why is zero conservative for the sump temperature calculation? How significant is this assumption?
- 14. July 30, 2007 letter Attachment 6 Section 3.2 RELAP5/MOD2-B&W is proposed for mass and energy release calculations as input to containment calculations. Please explain what changes have been made to ensure that RELAP5/MOD2-B&W is appropriately biased for this purpose. Address both the short term (peak containment pressure) and long term (NPSH) calculations Mail Envelope Properties (47EBBE65.B9A : 7 : 34856)
Subject:
Requests for Additional Information Creation Date 3/27/2008 11:33:57 AM From:
Michael Markley Created By:
MTM@nrc.gov Recipients nrc.gov TWGWPO01.HQGWDO01 GKL1 CC (Glenna Lappert) oppd.com dllippy (DONNA L LIPPY) medwards (MICHAEL EDWARDS) tcmatthews (THOMAS C MATTHEWS)
Post Office Route TWGWPO01.HQGWDO01 nrc.gov oppd.com Files Size Date & Time
MESSAGE 1157 3/27/2008 11:33:57 AM Second RAIs CS.doc 50688 3/27/2008 11:26:20 AM Update to RAIs on Dampers.doc 39936 3/27/2008 11:25:38 AM Options Expiration Date:
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