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g                                           February 2,1999 MEMORANDUM TO: Docket File '
. =. _.
FROM:                 Stephen Dembek, Project Manager Project Directorate 1-2 Division of Reactor Projects - 1/11 Office of Nuclear Reactor Regulation
g February 2,1999 MEMORANDUM TO: Docket File '
FROM:
Stephen Dembek, Project Manager Project Directorate 1-2 Division of Reactor Projects - 1/11 Office of Nuclear Reactor Regulation


==SUBJECT:==
==SUBJECT:==
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==Attachment:==
==Attachment:==
As stated
As stated
                                                                                                              'l1 l
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1 i
DISTRIBUTION Docket File PUBLIC WDean                                                                                                     .
DISTRIBUTION Docket File PUBLIC WDean SDembek
SDembek                                         ^ ' ,                                                      l
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g d[(i d#* gf NAME       SDembek W DATE       2/2/99 !
OFFICE PDI-2/PM g d[(i d#* gf NAME SDembek W DATE 2/2/99 !
OFFICIAL RECORD COPY DOCUMENT NAME: P:\RAl_ FORM.WPD                                                                           ;
OFFICIAL RECORD COPY DOCUMENT NAME: P:\\RAl_ FORM.WPD 9902080228 990202 PDR ADOCK 05000336 PDR
9902080228 990202 PDR     ADOCK 05000336 PDR           ,


l                   p uty l-              p            7,t UNITED STATES
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NUCLEAR REGULATORY COMMISSION
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2 WASHINGTON, D.C. 20666 4001
2 NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20666 4001
%,,,,, 8 February 2,1999 MEMORANDUM TO: Docket File FROM:
                  % ,,,,, 8                               February 2,1999 MEMORANDUM TO: Docket File FROM:                 Stephen Dembek, Project Manager Project Directorate 1-2 Division of Reactor Projects - 1/11 Office of Nuclear Reactor Regulation l                  
Stephen Dembek, Project Manager Project Directorate 1-2 Division of Reactor Projects - 1/11 Office of Nuclear Reactor Regulation l


==SUBJECT:==
==SUBJECT:==
MILLSTONE NUCLEAR POWER STATION, UNIT 2, DRAFT REQUEST l                                         FOR ADDITIONAL INFORMATION, LOSS OF MAIN FEEDWATER i                                         TRANSIENT ANALYSIS (TAC NO. MA4431)
MILLSTONE NUCLEAR POWER STATION, UNIT 2, DRAFT REQUEST l
The attached request for additional information (RAl) was transmitted by facsimile on February 2,1999, to Ravi Joshi of the licensee's staff. Review of the RAI would allow the
FOR ADDITIONAL INFORMATION, LOSS OF MAIN FEEDWATER i
!                  licensee to determine and agree upon a schedule to respond to the RAI and/or clarify issues l
TRANSIENT ANALYSIS (TAC NO. MA4431)
that may not need a formal response from the licensee. This memorandum and the attachment do not convey a formal request for information or represent an NRC staff position.                             -
The attached request for additional information (RAl) was transmitted by facsimile on February 2,1999, to Ravi Joshi of the licensee's staff. Review of the RAI would allow the licensee to determine and agree upon a schedule to respond to the RAI and/or clarify issues l
that may not need a formal response from the licensee. This memorandum and the attachment do not convey a formal request for information or represent an NRC staff position.
l Dockt,t No. 50-336 l
l Dockt,t No. 50-336 l


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l Stephen Dembek - ma43312.cpj Paga1l
l Stephen Dembek - ma43312.cpj Paga1l c.
: c.                                                                                                                               i g                             QUESTIONS RELATED TO THE NEW LOSS OF MAIN
g QUESTIONS RELATED TO THE NEW LOSS OF MAIN
                                            . FEEDWATER 1 RANSIENT ANALYSIS MILLSTONE UNIT 2 TAC MA4331 Please verify that for the new FSAR Chapter 14 loss of main-feedwater transient analysis non-safety related systems or components (for example; the pressurizer PORVs, sprays and heaters and steam generator dump valves) are modeled to assure conservative results. In other words, please verify that these systems are modeled if                             j they make the consequences worse and not modeled if they mitigate the consequences.                               '
. FEEDWATER 1 RANSIENT ANALYSIS MILLSTONE UNIT 2 TAC MA4331 Please verify that for the new FSAR Chapter 14 loss of main-feedwater transient analysis non-safety related systems or components (for example; the pressurizer PORVs, sprays and heaters and steam generator dump valves) are modeled to assure conservative results. In other words, please verify that these systems are modeled if j
The new FSAR Chapter 14 pages indicate that two single failures were considered for the loss of main feed event. Please verify that these single failures represent the most limiting single failure for each case analyzed for this event.
they make the consequences worse and not modeled if they mitigate the consequences.
                                                                                                                                      )
The new FSAR Chapter 14 pages indicate that two single failures were considered for the loss of main feed event. Please verify that these single failures represent the most
)
limiting single failure for each case analyzed for this event.
Please verify that the auxiliary feedwater flow assumed in the FSAR Chapter 14 analysis is a minimum flow including uncertainties, rather than a best estimate flow calculated for the FSAR Chapter 10 analysis.
Please verify that the auxiliary feedwater flow assumed in the FSAR Chapter 14 analysis is a minimum flow including uncertainties, rather than a best estimate flow calculated for the FSAR Chapter 10 analysis.
In accordance with the approved topical report, please describe how the conservative initial conditions for the analysis of this event were chosen. -In your responce please be specific only for the assumptions associated with the initial steam generator parameters and for the reactivity feedback.
In accordance with the approved topical report, please describe how the conservative initial conditions for the analysis of this event were chosen. -In your responce please be specific only for the assumptions associated with the initial steam generator parameters and for the reactivity feedback.
i The DNB aspects of the loss of main feed are assumed to be bounded by the loss of                                 j forced reactor coolant flow event. In general, the staff does not find it acceptable for an                     'I aspect of a " decrease in heat removal by the secondary system" to be bounded by a "                             l decrease in RCS flow event" (or any other different category event). The DNB transient                           I for the worst " decrease in heat removal by the secondary system" event should be                                 ,
i The DNB aspects of the loss of main feed are assumed to be bounded by the loss of j
analyzed in the FSAR.
forced reactor coolant flow event. In general, the staff does not find it acceptable for an
'I aspect of a " decrease in heat removal by the secondary system" to be bounded by a "
decrease in RCS flow event" (or any other different category event). The DNB transient I
for the worst " decrease in heat removal by the secondary system" event should be analyzed in the FSAR.
I i
I i
T
T
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Latest revision as of 02:23, 8 December 2024

Forwards Draft Request for Addl Info Re Loss of Main Feedwater Transient Analysis
ML20202H779
Person / Time
Site: Millstone 
Issue date: 02/02/1999
From: Stephen Dembek
NRC (Affiliation Not Assigned)
To:
NRC (Affiliation Not Assigned)
References
TAC-MA4431, NUDOCS 9902080228
Download: ML20202H779 (3)


Text

.

. =. _.

g February 2,1999 MEMORANDUM TO: Docket File '

FROM:

Stephen Dembek, Project Manager Project Directorate 1-2 Division of Reactor Projects - 1/11 Office of Nuclear Reactor Regulation

SUBJECT:

MILLSTONE NUCLEAR POWER STATION, UNIT 2, MILLSTONE NUCLEAR POWER STATION, UNIT 2, DRAFT REQUEST FOR ADDITIONAL INFORMATION, LOSS OF MAIN FEEDWATER TRANSIENT ANALYSIS (TAC NO. MA4431)

The attached request for additional information (RAI) was transmitted by facsimile on February 2,1999, to Ravi Joshi of the licensee's staff. Review of the RAI would allow the licensee to determine and agree upon a schedule to respond to the RAI and/or clarify issues that may not need a formal response from the licensee. This memorandum and the attachment do not convey a formal request for information or represent an NRC staff position.

Docket No. 50-336 l

Attachment:

As stated

'l 1

1 i

DISTRIBUTION Docket File PUBLIC WDean SDembek

j,g 9 6

^ ',

OFFICE PDI-2/PM g d[(i d#* gf NAME SDembek W DATE 2/2/99 !

OFFICIAL RECORD COPY DOCUMENT NAME: P:\\RAl_ FORM.WPD 9902080228 990202 PDR ADOCK 05000336 PDR

l p uty 7,t UNITED STATES l-p

5 j

NUCLEAR REGULATORY COMMISSION

(

2 WASHINGTON, D.C. 20666 4001

%,,,,, 8 February 2,1999 MEMORANDUM TO: Docket File FROM:

Stephen Dembek, Project Manager Project Directorate 1-2 Division of Reactor Projects - 1/11 Office of Nuclear Reactor Regulation l

SUBJECT:

MILLSTONE NUCLEAR POWER STATION, UNIT 2, DRAFT REQUEST l

FOR ADDITIONAL INFORMATION, LOSS OF MAIN FEEDWATER i

TRANSIENT ANALYSIS (TAC NO. MA4431)

The attached request for additional information (RAl) was transmitted by facsimile on February 2,1999, to Ravi Joshi of the licensee's staff. Review of the RAI would allow the licensee to determine and agree upon a schedule to respond to the RAI and/or clarify issues l

that may not need a formal response from the licensee. This memorandum and the attachment do not convey a formal request for information or represent an NRC staff position.

l Dockt,t No. 50-336 l

Attachment:

As stated 1 -

l l

J l

l l

l l

E l

l Stephen Dembek - ma43312.cpj Paga1l c.

g QUESTIONS RELATED TO THE NEW LOSS OF MAIN

. FEEDWATER 1 RANSIENT ANALYSIS MILLSTONE UNIT 2 TAC MA4331 Please verify that for the new FSAR Chapter 14 loss of main-feedwater transient analysis non-safety related systems or components (for example; the pressurizer PORVs, sprays and heaters and steam generator dump valves) are modeled to assure conservative results. In other words, please verify that these systems are modeled if j

they make the consequences worse and not modeled if they mitigate the consequences.

The new FSAR Chapter 14 pages indicate that two single failures were considered for the loss of main feed event. Please verify that these single failures represent the most

)

limiting single failure for each case analyzed for this event.

Please verify that the auxiliary feedwater flow assumed in the FSAR Chapter 14 analysis is a minimum flow including uncertainties, rather than a best estimate flow calculated for the FSAR Chapter 10 analysis.

In accordance with the approved topical report, please describe how the conservative initial conditions for the analysis of this event were chosen. -In your responce please be specific only for the assumptions associated with the initial steam generator parameters and for the reactivity feedback.

i The DNB aspects of the loss of main feed are assumed to be bounded by the loss of j

forced reactor coolant flow event. In general, the staff does not find it acceptable for an

'I aspect of a " decrease in heat removal by the secondary system" to be bounded by a "

decrease in RCS flow event" (or any other different category event). The DNB transient I

for the worst " decrease in heat removal by the secondary system" event should be analyzed in the FSAR.

I i

T

.m..

-4

,- -