ML18030B241
| ML18030B241 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 04/07/1986 |
| From: | Gridley R TENNESSEE VALLEY AUTHORITY |
| To: | Muller D Office of Nuclear Reactor Regulation |
| References | |
| TAC-57144, TAC-57145, TAC-57146, NUDOCS 8604150372 | |
| Download: ML18030B241 (8) | |
Text
REGULATORY INFORNATION DISTRlBUTION SYSTEM {RIDS)
ACCESSION NBR: 8604150372 '~ DOC. DATE: 86/04/07 NOTARIZED:
NO FACIL: 50-259 Browns Fev v g Nucleav'ower Stations Unit ii Tennessee 50-260 Browns Ferry Nuclear Power Stations Unit 2.
Tennessee 50-2V6 Bv'owns Fev v g Nucleav Power Stations Unit 3i Tennessee AUTH. NANF AUTHOR AFFILIATION QRlDLEY. R. L.
Tennessee Valley Authov itg REC IP. NAl'IE REC IP IENT AFFILIATION HULLER> D. R.
BWR Pv object Div'ectorate 2
DOCKET 05000259 05000260 05000296 05000259 05000260 05000296
SUBJECT:
Fov wav ds response to 860117 request For addi info v e vacuum bv eaker analysis. All calculations in CDI Rept 84.'3 show that plant design consev vative.
DISTRIBUTION CODE:
A001D COPIES RECEIVED: LTR ENCL SIZE:
TITLE:
OR Submittal:
Qeneral Distribution NOTES: NESS/FCAF icy.
NNSS/FCAF/PH icy.
OIA icg.
QROTENUIS, N icy.
NNSS/FCAF icy.
NNSS/FCAF/Pl'1 icy.
OIA icy.
QROTENHUIS. N icy.
NNSS/FCAF 1cg.
NNSS/FCAF/PN ice.
OIA icy.
QROTENHUIS> 5 icy.
RECIPIENT ID CODE/NANE BWR ADTS BWR EICSB BWR PD2 PD 01 BWR PSB INTERNAL: ACRS ELD/HDS4 NRR/GRAS RQN2 COPIES LTTR ENCL 1
0 2
5 5
1 6
6 0
1 0
1 RECIPIENT ID CODE/NANE BWR EB BWR FOB CLARKE R BWR RSB ADN/LFNB NRR/DHFT/TSCB F
04 COP IES LTTR ENCL 1
1 1
1 0
1 1
1 EXTERNAL: 24X LPDR NSIC NOTES:
03 05 1
1 1
1 1
EQ8(Q BRUSKEi S NRC PDR 02 TOTAL NUBBER OF COPIES REQUIRED:
LTTR 34 ENCL 30
'I E.
l 1'
w S TENNESSEE VALLEYAUTHORITY 5N 303B Lookout Place April 7, 1986 Director of Nuclear Reactor Regulation Attention:
Mr. D. R. Muller, Project Director BWR Project Directorate No.
2 Division of Boiling Water Reactor Licensing U.S. Nuclear Regulatory Commission Washington, D.C.
20555
Dear Mr. Huller:
In the Matter of the Tennessee Valley Authority Docket Nos.
50-259 50-260 50-296 By letter from R. J. Clark to H. G. Parris dated January 17,
- 1986, we received a request for additional information concerning the analysis of the vacuum breakers at Browns Ferry Nuclear Plant.
Our response to that request is enclosed.
If you have any questions, please call R.
E. Alsup at FTS 858-2725.
Very truly yours, TENNESSEE VALLEY AUTHORITY R. L. Gridley anager of Licensing Enclosure cc (Enclosure):
Mr. R. J. Clark U.S. Nuclear Regulatory Commission Browns Ferry Project Manager 7920 Norfolk Avenue
- Bethesda, Maryland 20814 U.S. Nuclear Regulatory Commission Region II ATTN:
Dr. J. Nelson Grace, Regional Administrator 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 8+04 1 50372 QQQ 5'Qq07D PDR ADOCY 050 DR P
P An Equal Opportunity Employer
I I
lh
/
ENCLOSURE
RESPONSE
TO NRC REQUEST FOR XNFORHATION REGARDING VACUUM BREAKERS BROWNS FERRY NUCLEAR PLANT Is the chugging source rate used in the evaluation the same as the one developed in CDI Report (PP 83-3)2 If not the same, provide the chugging source rate with the supporting justification.
TVA RESPONSE The methodology used to calculate the disc impact velocity for the BFN modifications was developed before issuance of CDX Report 84-3.
That methodology yielded an impact velocity of 6.89 radians/second which was used in the redesign of the vacuum breakers.
Calculations were subsequently performed using the chugging source rate developed in CDI Report 84-3 and this yielded an impact velocity of 6.60 radians/second.
Therefore, the BFN design is conservative with respect to CDI Report. 84.3.
Did the calculation apply the 1.07 load factor to account for the uncertainty in calculating the underpressure (section IV, of the staff's generic evaluation)2 TVA RESPONSE The calculations which were performed using the chugging source rate developed in CDI Report 84-3 used a load factor of 1.06 instead of 1.07.
Had a load factor of 1.07 been applied, the resulting impact velocity would have been 6.66 radians/second.
Therefore, the BFN design is conservative with respect to the CDI Report 84-3 source rate and a 1.07 load factor.
Have the calculations used the drywell model which results in the most conservative prediction (section V of the generic evaluation)2 TVA RESPONSE
.Calculations using the chugging source rate developed in CDZ Report 84-3 yielded the most conservative prediction when using the acoustic volume model.
That model was, therefore, used and resulted in an impact velocity of 6.60 radians/second.
The BFN design is based upon 6.89 radians/second impact velocity and is thus conservative.