ML18040A098
| ML18040A098 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 09/29/1993 |
| From: | Terry C NIAGARA MOHAWK POWER CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NMP1L-0784, NMP1L-784, TAC-M85003, NUDOCS 9310050081 | |
| Download: ML18040A098 (16) | |
Text
ACCELERATED OCUMENT DISTRIB ION SYSTEM REGULAT INFORMATION DISTRIBUTION STEM (RIDS)
ACCESSION NBR:9310050081 DOC.DATE: 93/09/29 NOTARIZED:
NO DOCKET N
FACIL 50-220 Nine Mile Point Nuclear Station, Unit 1, Niagara Powe 05000220 AUTH NAME AUTHOR AFFILIATION TERRY,PC.D.
Niagara. Mohawk, Power Corp.
RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)
SUBJECT:
Provides response to NRC request for addi info re review of Unit 1 torus reduction submittal of 910514.
DISTRIBUTION CODE:
AOOID COPIES RECEIVED:LTR I ENCL g SIZE: 7 TITLE: OR Submittal: General Distribution NOTES:
RECIPIENT ID CODE/NAME PD1-1 LA BRINKMAN,D.
COPIES LTTR ENCL 1
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2 RECIPIENT ID CODE/NAME PD1-1 PD COPIES LTTR ENCL 1
1 INTERNAL: ACRS NRR/DORS/OTSB NRR/DSSA/SPLB NUDOCS-ABSTRACT OGC/HDS1 EXTERNAL: NRC PDR 6
6 1
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1 1
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1 NRR/DE/EELB NRR/DRCH/HICB NRR/DSSA/SRXB OC KDCB EG FILE 01 NSIC 1
1 1
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1 NOTE TO ALL"RIDS" 1<ECIPIENTS:
PLEASE HEI.P US TO REDUCE WASTE! CONTACI TIIE DOCUMEN'I'ONTROL DIISI'.
ROOM I'1-37 (EY'I'. 504-2065) TO ELIMINATEYOUR NAME FROhl DIS'I'I<IIJUTION LISTS IIOIC DOCUMLNTS YOU DON'T NEED!
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I 1 '
PJl V MIIASAIRA W U SiÃ)HA%K NIAGARAMOHAWKPOWER CORPORATION/301 PLAINFIELDROAD, SYRACUSE, N.Y. 13212/TELEPHONE (315) 474-1511 September 29, 1993 NMP1L 0784 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 RE:
Nine MilePoint Unit 1 Docket No. 50-220 DPR-63 TA N
M 0
Gentlemen:
Subject:
NRC Request for AddMonal Information Regarding Re-review ofNine Mile Point Nuclear Station Unit 1 Torus Load Reduction Submittal of May 14, 1991 By letter dated August 26, 1993, the NRC requested additional information necessary to complete the re-review of our May 14, 1991 request to reduce the condensation oscillation loads in the Nine Mile Point Unit 1 Torus.
Attachment 1 to this letter provides our response to the requested information.
Ifyou have any questions regarding the response, please contact W. David Baker at (315) 428-7029.
Very truly yours, C. D. Terry Vice President - Nuclear Engineering MJM/lmc xc:
Regional Administrator, Region I Mr. B. Norris, Senior Resident Inspector Mr. R. A. Capra, Director, Project Directorate I-l, NRR Mr. D. S. Brinkman, Senior Project Manager, NRR Records Management 0<gO zs 9310050081 930929 PDR ADOCK 05000220 P,
ATTACHMENT1 RESPONSE TO THE NRC REQUEST FOR ADDITIONALIIWORMATIONREGARDING RE-REVIEW OF MAY14, 1991, TORUS LOAD REDUCTION SUBMITTAL NIAGAIu MOHAWKPOWER CORPORATION NINE MILEPOINT NUCLEAR STATION UNIT NO. 1 DOCKET NO. 50-220
I
Letter Report 7519-Rev.
1 September 17, 1993 Attachment Page 1
A LEDYNE ENQINEERlNG SERVlCES A DIVISIONOF TELEDYNE BROWN ENGINEERINO
RESPONSE
TO THE NRC RE UEST FOR ADDITIONAL INFORHATION REGARDING REREVIEW OF HAY 14 1991 TORUS LOAD REDUCTION SUBHITTAL
-NIAGARA HOHAWK POWER CORPORATION NINE HILE POINT NUCLEAR STATION UNIT NO.
1 DOCKET NO. 50-220 In Section 3.3. 1'of the Nine Hile Point Plant-Unique Analysis Report of the Torus Suppression Chamber (Teledyne Engineering Services (TES)
TR-5320-1, Rev.
1; September 21, 1984), it is stated that controlling load combination for the torus shell is that which combines DBA CO with the DBA hydrostatic pressure (P), deadweight (W) and the OBE (Case 20).
The NRC staff requests the following additional information and/or clarification with respect to this statement:
What fraction of the total shell stress (membrane,
- local, etc.)
derives from the CO loading?
From the P loading?
Etc.
Answer:
For Event Combination 20, Element No.
19 (the most limiting element),
the stresses from each of the contributing loads are as follows:
Original Analysis, Unreduced CO Load Hembrane Percent Stress of
~PS I Total Hembrane Percent
+ Bend'g of
~PS I Total Deadweight OBE Seismic Internal Pressure (DBA)
DBA CO Total Code Allowable.Stress 1,756 205 9,219 4 970 16,150 (16,025) 16,500 10.9%
1
~ 3%
57.0%
30:8%
100.0%
1,812 207 9,722 5 010 16,751 (16,618) 24,750 10.8%
1.2%
58.0%
30.0%
100.0%
Note:
The stresses in parentheses are from the report (TR-7353-1) and are the principal stresses calculated after all the component stresses from the four load cases are summed.
These are lower than the totals obtained by adding the principal stresses from each load case.
0
Letter Report 7519-Rev.
1 September 17, 1993 Attachment Page 2
ELEDYNE ENQINEERINQ SERVICES A DIVISIONOF TELEDYNE BROWN ENGINEERING 2.
After Case 20, what load combination involving CO loads induces the next highest stress in the torus shell?
What percentage of the total stress is due to CO?
Answer:
The next controlling event combination is Event Combination 14 for limiting Element No.
19, which includes deadweight, OBE
- seismic, internal
The stresses from each of the contributing loads are as follows:
Load Membrane Percent Stress of
~PS I Total Membrane Percent
+ Bend'g of
~PS I Total Oeadweight OBE Seismic Internal Pressure
( IBA)
SRV IBA CO 1,756 205 9,928 821 824 13.0%
1.5%
73.4%
6.0%
6.1%
1,812 207 10,470 2,385 I 596 11.0%
1.3%
63.6%
14.5%
9.6%
Total 13,534 (13,232)
Code Allowable Stress 16,500 100.0%
16,470 (15,148) 24,750 100 0%
Note:
The stresses in parentheses are the principal stresses calculated after all the component stresses from the five load cases are summed.
These are lower than the totals obtained by adding the principal stresses from each load case.
3.
What is the worst case load combination involving both CO and SRV loads?
What are the stress levels and their split for this case?
Answer:
The worst case load combination, for the limiting element 19, involving both CO and SRV loads is Event Combination 14.
See answer to guestion 2.
0
letter Report 7519-Rev.
1 September 17, 1993 Attachment Page' A
LEDYNE ENQlNEERlNG SERVlCES A DIVISIONOF TELEDYNE BROWN ENGINEERING 4,
What is the worst case load combination for the torus shell that does not involve CO?
How are the stresses for that case affected by the thinning of the torus shell?
How do they compare with the Case 20 stresses?
Answer:
The worst case event combination that does not involve CO is Event Combination 18 for Element No.
19, which includes deadweight, OBE
'seismic, and pool swell.
The stresses from each of the contributing loads are as follows:
Load Hembrane Stress membrane
+ Bending Deadweight OBE Seismic Pool Swell Total Code Allowable Stress 1,756 205 5 968 7,929 (7,812) 16,500 1,812 207
~6203 8,222 (8,103) 24,750 Note:
The stresses in parentheses are the principal stresses calculated after all the component stresses from the three load cases are summed.
These are lower than the totals obtained by adding the principal stresses from each load case.
These stresses would increase slightly due to the thinning of the torus shell.
- However, as can be
- seen, these stresses are approximately half the Event Combination 20 stresses, so the latter would control by a wide margin.
Referring now to Section 5.3 of TES TR-7353-1, Rev.
2 (January 14, 1992),
provide the following information/clarification:
5.
6.
Is the statement that
"...Event Combination 20...is controlling" valid for both 8 and 4 downcomer bays?
How is this established?
~Answe:
Yes.
It is established by comparing the stresses from the Event Combinations presented
- herein, (See response to question 8).
What shell thickness is used to calculate each of the "actual" stress levels tabulated in this section?
Answer:
The original thickness is used, t
= 0.46 inches.
0
Letter Report 7519-Rev.
1
~
September 17, 1993 Attachment
. Page 4
A LEDYNE ENGINEERING SERVICES A DIVISIONOF TELEDYNE BROWN ENGINEERING 7.
8.
Is the split in stresses due to the various contributing loads identical for the thinner shell case?
If it is not, state the fractional distribution.
Answer:
Yes.
It would be the same.
Is the split in stresses due to the various contributing loads identical for the 4
downcomer bay cases?
If it is not, state the fractional distribution?
Answer:
For Event Combination 20, Element No.
19, with reduced CO, the stresses from each of the contributing loads are as follows:
Reduced CO, 8 Downcomer Bays Load Membrane Stress
~PS I Percent of Total Nembrane Percent
+ Bend'g of PSI Total Deadweight OBE Seismic Internal Pressure (DBA)
DBA CO Total Code Allowable Stress 1,756 205 9,219 4 342 15,522 (15,452) 16,500 11.3%
1.3%
59.4%
28.0%
100.0%
1,812 207 9,722 4 381 16)122 (16,044) 24,750 11.3%
1.3%
60.'3%
27.1%
100.0%
Load Reduced CO, 4 Downcomer Bays Membrane Percent Stress of
~PS I Total Hembrane Percent
+ Bend'g of
~PS I Total Deadweight OBE Seismic Internal Pressure (DBA)
DBA CO 1,756 205 9,219 3 349 12.1%
1.4%
63.5%
23.0%
, 1,812 207 9,722 3 375
- 12. 0%
1.4%
64.3%
22.3%
Total 14,529 (14,460)
Code Allowable Stress 16,500 100.0%
15,116 (15,040) 24,750 100.0%
Note:
The stresses in parentheses are from the report (TR-7353-1) and are the principal stresses calculated after al-1 the component stresses from the four load cases are summed.
These are lower than the totals obtained by adding the principal stresses from each load case.
0 0
Letter Report 7519-Rev.
1 September 17, 1993 Attachment Pa'ge 5
A ELEDYNE ENGINEERING SERVlCES A DIVISIONOF TELEDYNE BROWN ENGINEERING 9.
Provide the equivalent response to questions 2
and 3 for th'e 4
downcomer bays'nswer:
Event Combination 20 is the only case involving DBA CO loads.
The next controlling event combination is Event Combination 14 which includes IBA CO.
This is also the worst case event combination involving both CO and SRV loads.
Since the load reduction being sought is only for DBA CO, there are no changes to the original values for the IBA CO results for Event Combination 14.
That is to
- say, there is no differentiation between the 4
and 8 downcomer 'bays for event combinations other than the revised Event Combination 20.
The results are presented in guestion 2.
.0 0
/g