ML20112E831
| ML20112E831 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 01/09/1985 |
| From: | Daltroff S PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | Eisenhut D Office of Nuclear Reactor Regulation |
| References | |
| IEB-80-11, NUDOCS 8501150289 | |
| Download: ML20112E831 (6) | |
Text
o PHILADELPHIA ELECTRIC COMPANY 2301 M ARKET STREET P.O. BOX 8699 PHILADELPHIA. PA.19101 SHIELDS L. DALTROFF
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January 9, 1985 Docket Nos. 50-277 50-278 Mr. Darrell G. Eisenhut, Director Division of Licensing U.S. Nuclear Regulatory Commission Washington, D.C.
20555
SUBJECT:
I.E. Bulletin No. 80-11 Masonry Hall Design
REFERENCE:
Letter, D.
G. Eisenhut, NRC, to E. G.
Bauer, Jr., PECo, dated October 30, 1984 (Masonry Wall
- Design, I.E.Bulletin 80-11)
Dear Mr. Eisenhut:
Your above referenced letter of October 30, 1984, transmitted the Commission's Safety Evaluation Report pertaining to Masonry Wall Design for our Peach Bottom Atomic Power Station.
The.
findings reported in the Safety Evaluation report concluded that-Philadelphia Electric Company has fully implemented, with'the exception of five walls, Items 2(b) and 3 of I.E. Bulletin No.-80-11 atiour Peach Bottom facility.
In addition, the Safety Evaluation' Report further concluded that, with the exception of the same f.i.ve walla, "there is a reasonable assurance that the safety-related masonry walls at Peach Bottom will withstand the specified design load conditions without impairment of (a) '.1211 integrity or (b),the performance of the required safety functions."
Your letter requected further information concerning the qualification of the five masonry walle.that were analyzed by Philadelphia Electric Company utilizing the energy balance technique.
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,s' B501150289 850109 PUR ADOCK 05000277 g
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Mr. Darrell G. Eisenhut January 9, 1985 Page 2 In response to your request, Philadelphia Electric Company has re-evaluated each of these five walls and has determined that these walls conform to the Commission's masonry wall design criteria.
The enclosed attachment, "The Re-evaluation by Elastic Methods of Blockwalls Previously Qualified by the Energy Balance Technique", provides evidence that there is reasonable assurance that these five safety-related masonry walls can withstand the specified load conditions without impairment of wall integrity or performance for the required safety functions.
As a result of this finding, Philadelphia Electric Company has concluded that modificdtion to these five walls will not be required to meet the Commission's masonry wall design criteria.
Should you have any questions or require additional information, please do not hesitate to contact us.
Very truly yours, r
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' i g (.f Attachment' cc:
J. F. Stolz, Chief, Operating Reactors Branch No. 4
.Dr. T. E. Murley, Administrator Region I, Office of Inspection & Enforcement J. H. Williams, Resident Inspector NRC Document Desk
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ATTACHMENT l
THE RE-EVALUATION BY ELASTIC METHODS OF BLOCKWALLS PREVIOUSLY QUALIFIED c.
BY THE ENERGY BALANCE TECHNIQUE FOR
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PEACH BOTTOM ATOMIC POWER STATION m;
UNITS 2 AND 3 DOCKET NUMBERS 50-277 AND 50-278 SUBMITTED TO U
THE UNITED STATES NUCLEAR REGULATORY COMMISSION JANUARY 1985 bL i 9
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ATTACUMENT Page 1 of 2
1.0 INTRODUCTION
-The re-evaluation of safety-related concrete masonry walls at Peach Bottom Atomic Power Station Units 2 and 3 was required by NRC I.E. Bulletin No. 80-11.
A report on the re-evaluation was submitted to the.NRClon May 4, 1981 and additional information and revisions were submitted on May 26, 1982 and March 21, 1984.
Asidiscussed in these submittals, five walls out of a total of 86.had been qualified by the use of the Energy Balance
-Technique.
This document contains all portinent data and the results of re-evaluation for the five masonry walls at Peach Bottom which are now qualified using the conventional elastic methods.
2.0 DESCRIPTION
OF MASONRY WALLS Two groups of walls were qualified on the basis of the Energy Balance Technique. -The walls representing these groups were wall number 68.2 (representing two walls - i.e., walls 68.2 and
'68.3) and wall number 532.1 (representing three walls - i.e.,
walls 532.1, 532.2 and 532.3).
The walls represented by wall number 68.2 are located at
. elevation 150-0 of the cable spreading room and their primary function is fire resistance.
They are 12 ft. high by 18 ft.
long and 8 in, thick single wythe walls with all sides simply supported.
The vertical reinforcement consists of #5 rebar at 32 in. spacing and horizontally (1) #4 rebar is placed in bond beams _ spaced at 64 inches.
The walls are grouted at reinforcement cells only.
The walls represented by wall number 532.1 are. located at elevation 158-0 of the emergency cooling tower and are fire-resistant bearing walls.
They are about 15 f t.
high by 24 ft.
long and 12 in. thick single wythe walls with all sides simply supported.
The vertical reinforcement consists of (2) #4 rebar at 32 in. spacing and horizontally (2) 14 rebar are placed in bond beams spaced at 64 inches.
The walls are also grouted at reinforcement cells only.
For these five walls, the material description is as follows:
(i)
-Mortar type:
ASTM C-270, type N (ii)
Concrete block type:
ASTM C-90, Grade U-l (iii) Group strength at 28 days:
2000 psi
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ATTACHMENT Page 2 of 2
-(iv) Reinforcing bar:- ASTM A-615. Grade 40 for #3 through #7 and grade 60 for bars larger than #7.
These five walls are not a part of the lateral load resisting system.
.3.0 ANALYSIS Seismic loads were the governing case for these five walls.
The re-evaluation criteria of I.E. Bulletin No. 80-11 permits for OBE and SSE the use of 4% and 7% damping curves, respectively, for cracked conditions.
The conservatism of the previous analysis (based on 2% and 5% dampings for OBE and SSE) was reduced-and these higher dampings were used for the response acceleration computations for all of the five walls.
'In view of the significant openings in walls 68.2 and 68.3, three uninterrupted segments of the walls were analyzed as one-way beams, two vertical and one horizontal.
In addition to carrying their.own inertia load, these beams were loaded by the parts of.the walls that were interrupted by the openings.
- Also, wherever applicable, the reinforcement around the openings as shown on.the project' drawing number S-246, Rev.
5, were considered to-resist the applied loads.
All three beams were conservatively analyzed using the peak response acceleration regardless of the frequency.
.The three_ walls represented by wall number 532.1 (i.e, 532.1,
- 532.2 and 532.3) were analyzed as a plate with four sides simply supported.
In the analysis, the peak response acceleration was also conservatively used.
The results of the analysis indicate that all these five walls meet the requirements of the working stress re-evaluation criteria'and, consequently, are qualified without the use of the Energy: Balance Technique.
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4.0 CONCLUSION
S Based on the inherent conservatism of the analytical approach as outlined in Section 3.0, it is concluded that the five walls discussed in this report are structurally adequate under all applicable loadings, and'are now qualified in accordance with the conventional working stress criteria.
COMMONWEALTII OF PENNSYLVANIA :
ss.
' COUNTY OF PIIILADELPIIIA S. L. Daltroff, being first duly sworn, deposes and says:
That he is Vice President of Philadelphia Electric Company; that he has read the foregoing response with respect to I.E.Bulletin 80-11 and knows the contents thereof; and that the statements and matters set forth therein are true s
and correct to.the best of his knowledge, information and belief.
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Subscribed.and sworn to before me thisib day o f IOdd N 1, l'88f Q-nlE t
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Notary Public JUDITH Y. FRANKLIN Notary Public, Phila.. Phila. Co.
My Commission Exoires Juhr 28,1987 p-f p'
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