ML19289F629
| ML19289F629 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 06/06/1979 |
| From: | Counsil W NORTHEAST UTILITIES |
| To: | Ziemann D Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7906150208 | |
| Download: ML19289F629 (8) | |
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((,Y,.UN ',, d HARTFORD. CONNECTICUT 06101 (2p en CT[,',",,]. "(,- g June 6, 1979 Docket No. 50-245 Director of Nuclear Reactor Regulation Attn: Mr. D. L. Ziemann, Chief Operating Reactors Branch #2 U. S. Nuclear Regulatory Commission Washington, D. C. 20555
References:
(1) W. G. Counsil letter to B. H. Grier (Region 1) dated April 24, 1979. (2) W. G. Counsil letter to B. H. Grier (Region 1) dated April 30,1979. Gentlemen: Millstone Nuclear Power Station, Unit No.1 I&E Bulletin #79-07 Additional Information In Reference (1), Northeast Nuclear Energy Compeny (NNECO) provided the response to I&E Bulletin 79-07 regarding seismic stress analysis of safety-related piping. Following that submittal, the Staff verbally requested separate additional information on this subject, which is provided herein. As delineated in Reference (1), the Millstone Unit No.1 piping systems were originally designed, utilizing computer programs employing techniques for combining responses of orthogonal earthquake motion other than algebraic summation. To date, two tasks have been undertaken involving piping reanalysis. These tasks were performed utilizing the ADLPIPE computer program and analyzing all three directions simultaneously, a feature which results in algebraic summation of responses. The taske analyzed were as follows: (1) Re-routing of approximately eight (8) feet of three-inch piping in the Control Rod Drive return piping, from the feedwater tie-in to the second isolation valve. (2) Installation of the 1-CU2 (valve) bypass line; a one-half inch diameter bypass line around c valve in the clean-up water supply. Subsequent to the submittal of Reference (1), affected portions of these systems have been reanalyzed using the ADLPIPE (FAST) February,1979, Revision 1B computer code, and static analysis techniques to calculate responses to eart.hquake motion, as described in Section XII and Amendment 2229 290. 3o.2cg:
. Nos.14 and 17 of the Millstone Unit No.1 FSAR. In the reanalysis, seismic loads were applied to two perpendicular horizontal directions and the vertical direction, in three individual analyses. The results from one horizontal direction were combined absolutely with the results from the vertical direction and compared with the results from the other horizontal direction, combined with the vertical direction. The larger of the two results was used. The peak stresses from the reanalysis for the OBE and DBE conditions as well as calculated support loadings are tabulated in the Attachment. For comparison, the results from the original analysis using algebraic summation techniques described in Reference (1) are also tabulated in the Attachment. All stresses are within allowable limits specified in the Millstone Unit No.1 FSAR. However, the loading for one anchor on the CRD exhaust line has exceeded the original design loading. This support will be modified to accommodate the increased loading prior to Cycle 7 startup. The redesign of this support will conform to requirements specified in I&E Bulletin 79-02. All other support loads remain within the original design loadings. NNECO has investigated the impact of the modifications with regard to the High Energy Pipe Break (HEPB) study previously performed. These modifications have not affected the validity of the HEPB study previously docketed. NNECO has also reviewed the impact of I&E Bulletin 79-04 on these two systems. Our docketed response to Bulletin 79-04, Reference (2), shows that no unconserva-tive usage of Velan valve weights has been incorporated into these or other analyses. NNECO had also completed an as-built verification of the two modifications prior to this reevaluation as part of the original modification program. In summary, the systems previously identified will conform to criteria for seismic systems delineated in the Millstone Unit No.1 FSAR prior to Cycle 7 startup, and will, therefore, be acceptable for continued use. We trust tha t you find the above information, coupled with References (1) and (2), responsive to your concerns on this issue. Very truly yours, NORTHEAST NUCLEAR ENERGY COMPANY q l ,0b(0Q N. G. Counsil Vice President Attachment 2229 29l
s DOCKET No. 50-245 ATTACHMENT MILLSTONE NUCLEAR POWER STATION, UNIT NO.1 16E BULLETIN #79-07 ADDITIONAL INFORMATION 2229 292 JUNE, 1979
REANALYSIS MAX. CALC. STRESSES (1) (2) (3) (4) Pres-DBE DBE Static "G" Weight sure OBE 17/7x(3) OBE OBE DBE Allowable Factor Pipe Stress Stress Stress Stress Cond. Allowable Cond. Yield Stress System X,Z Y Size (PSI) (PSI) (PSI) (PSI) (1)+(2)+(3) 1.25h (1)+(2)+(4 ) (PSI) 1-CU2 Bypass .50 .05 1/2" 627 3798 6102 14820 10527 17280 19245 19500 Sch 80 (Data Pt. 105){ f 8 8768 18000 12168 l 35000 CRD Exhaust .50 .05 3" 3184 3204 2380 5780 Sch 160 l(Data Pt. 25) l l Original Analysis Using Dynamic Response Spectra w/ Algebraic Summation Technique (1) (2) (3) (4) Pre,- DBE DBE Weight su 2 OBE Stress OBE OBE DBE Allowable Pipe Stress Stress Stress 17/7x(3) Cond. Allowable Cond. Yield Stress System Size (PSI) (PSI) (PSI) (PSI) (1)+(2)+(3) 1.25h (1)+(2)+(4) (PSI) i 1-CU2 Bypass 1/2" Sch 80 627 3798 3212 7800 7637 l 17280 12225 19500 (Data Pt.105) I I i CRD Exhaust 3" Sch 160 3184 3204 767 1863 j 7155 j 18000 8251 35000 (Data Pt. 25) i i i N N N< N< U
Page 2 REANALYSIS Restraint Loadings Due To Seismic Loadings Support Support OBE DBE Data Point Type Direction Load Load 135 Snubber X 10 24 135 Snubber Z 27 66 i N0ZZLE LOADINGS CU2 Bypass Data Point 155 OBE Loading DBE Loading (17/7 x OBE Load) Fx (lbs.) 5 12 Fy (lbs.) 10 24 Fz (1b s. ) 4 10 Mx (f t-lbs.) 8 19 My (f t-lbs.) 8 19 M (f t-lbs. ) 3 7 2 Data Point 180 OBE Loading DBE Leading (17/7 x OBE Load) Fx (lbs.) 65 158 Fy (lbs.) 7 17 N Fz (1b s. ) 42 102 N N Mx (f t-lbs.) 15 36 My (f t-lbs.) 217 527 N M (ft-lbs.) 23 56 z w ->m
~ Page 3 ORIGINAL ANALYSIS 1CU2 BYPASS RESTRAINT LOADINGS DUE TO SEISMIC LOADINGS Support Support OBE DBE Design Data Point Type Direction Load Load Load l 135 Snubber X 8 19 500 h 135 Snubber Z 12 29 500 i 6 Nozzle Loadings Due To Seismic Loadings Data Point 155 OBE Loading DBE Loading (17/7 x OBE Load) Fx (lbs. ) 7 17 Fy (lbs.) 27 66 F (lbs.) 3 7 z Mx (f t-lbs. ) 4 10 My (ft-lbs.) 4 10 Mz (ft-lbs.) 5 12 Data Point 180 OBE Loading DBE Loading (17/7 x OBE Load) Ne Fx (lbs.) 11 27 Fy (lbs.) 4 10 g 4 Fz (lbs.) 15 36 L.n Mx (ft-lbs.) 3 7 My (f t-lbs.) 97 236 Mz (ft-lbs.) 4 10
Page 4 REANALYSIS CRD Exhaust Restraint Loading - Data Support Wgt. Thermal OBE DBE Point Type Direction Load Load Load Load Total 24 Rigid Y 666 720 215 522 1908 REANALYSIS CRD EXilAUST Anchor Loading - Due to Earthquake Loadings Data Point 25* OBE Loading DBE Loading (17/7 x OBE Load) Fx (lbs.) 670 1627 42 102 Fy (lbs.) Fz (lbs.) 350 850 Mx (f t-lbs. ) 37 90 My (f t-lbs.) 2834 6882 Mz (ft-lbs.) 56 136 Nozzle Loading - Due to Earthquake Loading Data Point 1 OBE Loading DBE Loading (17/7 x OBE Load) g N N Fx (lbs.) 107 260 Fy (lbs.) 177 430 N Fz (1bs.) 233 566 Ch Mx (f t-lbs.) 128 311 My (f t-lbs.) 89 216 Mz (f t-lbs.) 18 44
Page 5 ORIGINAL ANALYSIS CRD Exhaust Restraint Loading Data Support Wgt. Thermal OBE DBE Total Original Point Type Direction Load Load Load Load Load Design Level 24 Rigid Y 666 720 232 563 1949 2000 ORIGINAL ANALYSIS CRD Exhaust Anchor Loading Due To Earthquake Loadings Data Point 25_ OBE Loading DBE Loading (17/7 x OBE Load) Fx (lbs.) 77 187 39 95 Fy (lbs.) Fz (lbs.) 49 119 Mx (f t-lbs.) 44 106 425 1032 My (f t-lbs.) Mz (f t-lbs.) 95 231 ORIGINAL ANALYSIS CRD Exhaust Nozzle Loading Due to Earthquake Ioads N N Data Point 1 OBE Loading DBE Loading (17/7 x OBE Load) N< N Fx (lbs.) 58 141 W 185 449 N Fy (1bs.) Fz (lbs.) 175 425 Mx (f t-lbs.) 208 505 170 413 My (f t-lbs.) M (ft-lbs.) 23 56 2
- This anchor will be redesigned to carry the loadings determined in the reanalysis.}}