ML20137C908
| ML20137C908 | |
| Person / Time | |
|---|---|
| Site: | 05200003 |
| Issue date: | 03/24/1997 |
| From: | Diane Jackson NRC (Affiliation Not Assigned) |
| To: | NRC (Affiliation Not Assigned) |
| References | |
| NUDOCS 9703250168 | |
| Download: ML20137C908 (11) | |
Text
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March'24, 1997 1
APPLICANT: Westinghouse Electric Corporation FACILITY:
AP600
SUBJECT:
SUMMARY
OF TELEPHONE CONFERENCE TO DISCUSS ';TAFF COMMENTS ON A WG0THIC COMPUTER CODE AND PASSIVE CONTAINMLNI COOLING SMTEM REPORT The subject telephone conference was held on March 13, 1997, between Joel Woodcock, Mike Loftus, and Bruce Rarig of Westinghouse Electric Corporation (Westinghouse) and Ed Throm and Diane Jackson of the Nuclear Regulatory Commission (NRC). This telephone conference, as agreed upon at the March 7,1997, meeting, was to discuss staff comments on the Westinghouse report WCAP-14812, " Accident Specification and Phenomena Evaluation for AP600 Passive Contai m r,t Cooling System." The staff had provided general guidance in a letter dated March 4, 1997. A list of discussion items were sent to Westinghouse via facsimile (Attachment 1) prior to the telephone conference to facilitate discussion.
The staff discussed each of its comments regarding the report. Westinghouse stated they would either make the changes or investigate possible alternativos to address the comment.
It was noted by the staff that the comments were not regulatory requirements, however, if implemented, they would increase the clarity and the staff's understanding of the report.
For many of the comments, Westinghouse agreed and committed to provide a draft markup to reflect the changes in an effort to expedite the review. A status of the comments is listed in Attachment 2.
The staff and Westinghouse agreed to hold a meeting on March 25, 1997, in the NRC Rockville office to discuss questions 3
on Chapters 7 and 9 of WCAP-14407, 'WG0THIC Application to AP600."
original signed by:
Diane T. Jackson, Project Manager Standardization Project Directorate Division of Reactor Program Management Office of Nuclear Reactor Regulation Docket No.52-003 Attachments: As stated gg g gg] g c w a ta ents:
yh~ q% if DISTRIBUTION:
Iu See next page 250043 DOCUMENT NAME: A:SCS3 13T. SUM T,seehe o espy of this doessnent, hudiiste in the ben: *C' = copy without ettechment/ enclosure
- E' = Copy with attachment / enclosure "N* = No copy 0FFICE PM:PDST:DPRM D:PDST:DRPM i l
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NAME DTJackson:sg W TRQuay 7)W l
DATE 03/31/97 U
03/ M 97 l
OFFICIAL RECORD COPY 9703250168 970324 PDR ADOCK 05200003 E
Westinghouse Electric Corporation Docket No.52-003 cc: Mr. Nicholas J. Liparulo, Manager Mr. Frank A. Ross Nuclear Safety'and Regulatory Analysis U.S. Department of Energy, NE-42 Nuclear and Advanced Technology Division Office of LWR Safety and Technology Westinghouse Electric Corporation 19901 Germantown Road P.O. Box 355 Germantown, MD 20874 Pittsburgh, PA 15230 Mr. Ronald Simard, Director Mr. B. A. McIntyre Advanced Reactor Program Advanced Plant Safety & Licensing Nuclear Energy Institute Westinghouse Electric Corporation 1776 Eye Street, N.W.
Energy Systems Business Unit Suite 300 Box 355 Washington, DC 20006-3706 Pittsburgh, PA 15230 Ms. Lynn Connor Ms. Cindy L. Haag Doc-Search Associates Advanced Plant Safety & Licensing Post Office Box 34 Westinghouse Electric Corporation Cabin John, MD 20818 Energy Systems Business Unit Box 355 Mr. James E. Quinn, Projects Manager Pittsburgh, PA' 15230 LMR and SBWR Programs GE Nuclear Energy Mr. M. D. Beaumont 175 Curtner Avenue, M/C 165 Nuclear and Advanced Technology Division San Jose, CA 95125 Westinghouse Electric Corporation One Montrose Metro Mr. Robert H. Buchholz 11921 Rockville Pike GE Nuclear Energy Suite 350 175 Curtner Avenue, MC-181 Rockville, MD 20852 San Jose, CA 95125 Mr. Sterling Franks Barton Z. Cowan, Esq.
U.S. Department of Energy Eckert Seamans Cherin & Mellott NE-50 600 Grant Street 42nd Floor 19901 Germantown Road Pittsburgh, PA 15219 Germantown, MD 20874 Mr. Ed Rodwell, Mansger Mr. S. M. Modro PWR Design Certification Nuclear Systems Analysis Technologies Electric Power Research Institute Lockheed Idaho Technologies Company 3412 Hillview Avenue Post Office Box 1625 Palo Alto, CA 94303 Idaho Falls, ID 83415 Mr. Ben Gitnick Mr. Charles Thompson, Nuclear Engineer Scientech, Inc.
AP600 Certification 11140 Rockville Pike NE-50 Suite 500 19901 Germantown Road Rockville, MD 20852 Germantown, MD 20874
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DISTRIBUTION w/ attachments:
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TKenyon 8Huffman i
DTJackson JSebrosky l
EThrom, 0-8 H7 DISTRIBUTION w/o attachment:
SCollins/FMiraglia, 0-12 G18 AThadant, 0-12 G18 RZimmerman, 0-12 GIS 1
TMartin MSlosson TQuay Dross, T-4 D18 l
WDean, 0-17 G21 ACRS (11)
JMoore, 0-15 B18 CBerlinger, 0-8 H7 GHolahan, 0-8 E2 i
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a Comments on WCAP-14811 Page Paragraph Comment Section i
1-1 1.1 Regulatory need is embedded in 52.47(2)(1). Also, there is a tie into the DBA EM. Need to support or 4
confirm "the" model.
PIRT should tell you if you i
have, or needed to obtain, appropriate data and on the appropriate scale. Results of these should tell you if you have sufficient information or if you need to bound or conservatively address some items.
I l-7 1-st i Should note spent fuel pool makeup rele of PCCWST Might mention segregated fire protection volume 1-7 1.4 *7 Should condensation on the baffle be added 1-5 Figure 1-3 4
j There are now three " stand pipes" in the PCCWST, see for example SSAR Rev 11 Figure 6.2.2-1 ix 3-rd i Update tank size l-6 1-st i 1
ix 4-th i examples of type of phenomena addressed in reports might be useful 2-1 2.0 Should be clear that this reports replaces Ref. 7 Should indicate this reports includes new information 2-3 2.2 Ref. 8 most likely lists all AP600 tests, should clarify (Ref. 8 is not only for PCS)
)
2-3 2.2 Could be helpful to outline the testing pro After the phenomena identification process, gram.
found i
need for coverage and wetting data (which tests);
found need for mass transfer (which tests) and heat transfer (which tests) data - existing tests vs needed for AP600; scale to AP600 Addition tests on specific downcom(which tests).
er riser design, i
external wind effects, etc.
2-6 2.2.5 What about contact angle measurements?
What about the " aged" test?
2-7 Top of page Note new AP600 flows: 440 to 18 gpm.
1 2-7 2.2.7 Provide list of parameters valid for LST; reference Section 11 of Scaling report for atypicalities. (See also last 1 in section - update to scaling report reference.)
2-7 Last i Note that DBA range covered in LST did not include LOCA blowdown (and long, long term post-72 hours?)
e am
i i
f 3-2 3.2 Containment volume 1.7 or 1.74?
t 3-3 3.2.1 I
l 3-7 Table 3-1 Assure data is consistent with scaling report and application reports.
If scaling report uses j
different values, explain why.
3-9 Table 3-2 Should probable update values to more recent analyses. Add column of pressures at 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> for i
LOCA: two criteria (a) peak and (b) long term.
3-10 Table 3-3 Initial environmental humidity is given as 25%.
Previously, 20% had been used. What is the basis i
for this change. The question of recycle of air
)
i should be addressed.
i.
3-15 3.4.2.1 100 ; r ::t full power; 102% by " rules"
{
[
3-17 4-th 1 While phrases such as " generally" or " typically" may read well, unless exceptions are clear or spelled out j
j they tend to only lead to confusion (is there something the reader should be concerned with?).
4 Specific case: a break spectrum is analyzed to find limiting case (size and location) i because of the complex nature of the thermal-hydraulic processes.
1.
3-21 Table 3-4 Add column of expected temperatures to demonstrate i
comments about T being too low to... significantly.
3-21 Table 3-4 Data indicates that full coverage occurs 5 minutes e
after pipe and bucket fills.
Is this consistent with the previous full coverage (considering change in i
flow rate) which was 5 minutes after second weir fills?
3-21 Table 3-5 In the sequence of events, it seems that IRWST drain j
down and sump injection of saturated liquid are a
significant events. When do these occur?
t-
[
3-23 3.4.3.1
" generally" 30% is a result of documented studies 3-rd 1 that show this is the limiting break, reference them.
n/a n/a Provide sources of values:
examples:
4-4:
minimum vapor fraction l
emissivity 1
i beam lengths j
4-5' liquid film Statement that 15% of condensed steam enthalpy is thermal carried away by the film should be justified.
{
transport 4-5 liquid films Justify the film thickness limit in the presence of conductance air counter-current flow.
4
' source of the 10% (test data, scaling, water 4-7 1-st
- properties) 4-16 4.3.2 *4 -2 How does this statement support a low rank for inter-compartment flow during blowdown? Is not mass transfer (condensation) important to defining the heat sink temperatures at the end of blowdown?
f 4-30 4.4.2A High rank for all phases; related to inter-compartment convective transfer.
4-18 2-nd
- PIRT Low ranking shouldn't be used to justify a ranking nonconservative treatment in the model. Capturing the major features alone isn't enough. The model chosen shouldn't introduce uncertainty of unknown magnitude.
l 4-19 4.4.lA The LST covered a range of data.
What range?
4-31 4.4.7A convection: why couple to condensation? : who is it?
4 ALSO: implies 5% as a screening criterion.
4-34 4.4.7L Film conduction may be ranked low, but it is in series (not parallel) with major heat removal mechanisms. The uncertainty is therefore important and needs to be addressed.
4-40 4.4.10E Explain why WG0THIC predicts condensation on the i
baffle for only 3 seconds after PCS water is applied.
What is the physical basis for this prediction?
n/a 4.4.llD nomenclature (r =p c,6 / h )
2 4.4.9B pv / 2 i
n/a 4.4.12 Does thinning tank walls (post 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> design changes) affect conclusions?
n/a n/a LWhen? : M&Es, PCS flow (post 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />), etc. (any (not PIRT) other changes); data needed for NRC confirmatory General Q analyses of DECLG LOCA and MSLB.
=..
l
}
Status of open items after telephone conference:
f Mtg Page Paragraph Comment Westinghouse Open Section Item response l
No.
l 1
1-1 1.1 Regulatory need is embedded in Westinghouse 52.47(2)(i). Also, there is a will review tie into the DBA EM. Need to support or confirm "the" model.
4 PIRT should tell you if you have, or needed to obtain, appropriate data and on the i
appropriate scale.
Results of these should tell you if you have sufficient information or if you need to bound or t
conservatively address some items.
2 1-7 1-st 1 Should note spent fuel pool Westinghouse makeup role of PCCWST will make these Hight mention segregated fire changes t
protection volume 1-7 1.4 +7 Should condensation on the i
baffle be added 1-5 Figure 1-There are now three " stand t
3 pipes" in the PCCWST, see for example SSAR Rev 11 Figure 6.2.2-1 ix 3-rd i Update tank size 1-6 1-st 1 ix 4-th i examples of type of phenomena addressed in reports might be useful 2-1 2.0 Should be clear that this reports replaces Ref. 7 Should indicate this reports includes new information 3
2-3 2.2 Ref. 8 most likely lists all Westinghouse AP600 tests, should clarify will review (Ref. 8 is not only for PCS) l J
2 I
Mtg Page Paragraph Comment Westinghouse Open Section response Item No.
4 2-3 2.2 Could be helpful to outline the Westinghouse testing program. After the will review 4
phenomena identification process, found need for 4
coverage and wetting data (which tests); found need for mass transfer (which tests) and heat transfer (which tests) data - existing tests vs needed for AP600; scale to AP600 (which tests). Addition tests on specific downcomer riser design, external wind effects, etc.
5 2-6 2.2.5 What about contact angle Westinghouse measurements?
will make these What about the " aged" test?
changes 2-7 Top of Note new AP600 flows: 440 to 18 page gpm.
2-7 2.2.7 Provide list of parameters 4
valid for LST; reference Section 11 of Scaling report for atypicalities. (See also last 1 in section - update to scaling report reference.)
2-7 Last i Note that DBA range covered in LST did not include LOCA blowdown (and long, long term post-72 hours?)
3-2 3.2 Containment volume 1.7 or 1.74?
3-3 3.2.1 3-7 Table 3-1 Assure data is consistent with scaling report and application reports.
If scaling report uses different values, explain why.
3-9 Table 3-2 Should probable update values to more recent analyses. Add column of pressures at 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> for LOCA: two criteria (a) peak and (b) long term.
2
__ _ _. _ _.. _ _._... _ __ _. _._.. _ _ _.. _ _ _ _. _ _ __. y j
i Mtg Page Paragraph Comment Westinghouse
{
Open Section Item response j
No.
l 6
3-10 Table 3-3 Initial environmental humidity Westinghouse is given as 25%.
Previously,
will review 20% had been used. What is the basis for this change. The question of recycle of air I
should be addressed.
i 7
3-15 3.4.2.1 100 ;:r:=t full power; 102% by Westinghouse
" rules" will change text 8
3-17 4-th 1 While phrases such as Westinghouse
" generally" or " typically" may will review and read well, unless exceptions try to remove are clear or spelled out they statements tend to only lead ~to confusion using typically (is there something the reader and generally should be concerned with?).
to be more Specific case: a break spectrum descriptive (size and location) is analyzed to find limiting case because of the complex nature of the thermal-hydraulic processes.
9 3-21 Table 3-4 Add column of expected Westinghouse temperatures to demonstrate will change comments about T.being too low to... significantly.
10 3-21 Table 3-4 Data indicates that full No change coverage occurs 5 minutes after needed in this pipe and bucket fills.
Is this report.
consistent with the previoua However full coverage (considering Westinghouse change in flow rate) which was will check Ch.7 5 minutes after second weir of WCAP-14407 fills?
for consistency 11 3-21 Table 3-5 In the sequence of events, it Westinghouse seems that IRWST drain down and will make these sump injection of saturated changes liquid are significant events.
When do these occur?
i 3-23 3.4.3.1
" generally" 30% is a result of 3-rd i documented studies that show this is the limiting break, reference them.
i 3
)
i m
w
l Mtg Page Paragraph Comment Open Section Westinghouse Item response No.
3 n/a n/a Provide sources of values:
examples:
4-4: minimum vapor fraction emissivity beam lengths 4-5 liquid Statement that 15% of condensed film steam enthalpy is carried away thermal by the film should be transport justified.
4-5 liquid Justify the film thickness films limit in the presence of air conductan counter-current flow.
ce 4-7 1-st
- source of the 10% (test data, scaling, water properties) h 12 4-16 4.3.2 How does this statement support Westinghouse i
+4 -2 a low rank for inter-will review i
compartment flow during 1
blowdown? Is not mass transfer (condensation) important to 4-30 4.4.2A defining the heat sink temperatures at the end of j
blowdown?
High rank for all phases; related to inter-compartment convective transfer.
13 4-18 2-nd
- Low ranking shouldn't be used Westinghouse PIRT to justify a nonconservative will review ranking treatment in the model.
Capturing the major features alone isn't enough. The model chosen shouldn't introduce uncertainty of unknown magnitude.
14 4-19 4.4.lA The LST covered a range of Westinghouse data. What range?
will revise to be more specific 15 4-31 4.4.7A convection: why couple to Westinghouse condensation? : who is it?
will make this ALSO: implies 5% as a screening change criterion.
4
Mtg Page Paragraph Comment Westinghouse Open Section Item response No.
15 4-34 4.4.7L Film conduction may be ranked Westinghouse low, but it is in series (not will review parallel) with major heat removal mechanisms. The uncertainty is therefore important and needs to be addressed.
4-40 4.4.10E Explain why WGOTHIC predicts Westinghouse l
condensation on the baffle for will review -
only 3 seconds after PCS water this is already is applied. What is the a RAI physical basis for this prediction?
4 16 n/a 4.4.11D nomenclature (r -p c,6 / h )
Westinghouse 4.4.98 pv/2 will define its 2
nomenclature 17 n/a 4.4.12 Does thinning tank walls (post Westinghouse 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> design changes) affect will review conclusions?
n/a n/a 2When? : M&Es, PCS flow (post No action (not 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> etc. (any other needed changes));, data needed for NRC PIRT)
General Q confirmatory analyses of DECLG
4 5
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