ML20069A259
| ML20069A259 | |
| Person / Time | |
|---|---|
| Site: | 05000000, Dresden |
| Issue date: | 08/21/1979 |
| From: | Chen P Office of Nuclear Reactor Regulation |
| To: | Kuo P Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20069A188 | List: |
| References | |
| FOIA-82-399, TASK-03-06, TASK-3-6, TASK-RR NUDOCS 7909280656 | |
| Download: ML20069A259 (2) | |
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MEMORANDUM FOR:
P. T. Kuo, Group, Leader, Seismic Review Group, D0R FROM:
P. Y. Chen Seismic Review Group. DOR
SUBJECT:
DRESDEN-2 SEISHIC EVALUATION REPORT
Reference:
Memo from P. Y. Chen to Charles Hofmayer "Coments on Chapter 6 of the Dresden-2 Seismic Esaluation Report" dated July 5.1979 In response to your request, I have brdefly summarized a few items of interest from the telephone convers4 tion between Drs. Newmark and Bill and NRC personnel on August 2,1979.
r Participants in the telephone coneersation were:
i NRC - C. Hofmayer, Howard Levin, T. Cheng, X. Jabbour, P. Y. Chen Consultants - N. M. Newmark, W. J. Hall 1.
Dr. Newmark opened the conversation by adknowledging receipt of comments from P. Y. Chen (above reference) and from other NRC personnel.
2.
Dr. Newmark stated that the original idea on the SEP program was to have SSRT going through the plant, examining structures, and equipment, and then write a 5 to 6 page SER to assess the plant seismic adequacy.
Therefore it was not intended to review every aspect of the structures 1,
and equipment.
3.
With re.ipect to my comment No. 5 of the above reference on the subject.
Drs. Newmark and Hall decided to add the attached Section 4 to the end of the Chapter 1 Section entitildd " Concluding Evaluation and Assessment".
In the added statement Das. Newmark and Hall pointed out that the functional l
l reliability of electrical equipment and, to a lesser degree, that of me<.hanical equipment arc amc,ng the most difficult items to evaluai.e.
However, the SSRT group believe that the equipment will fmain functional undderthe design hazard. They further stated that this conclusion is predicated upon the considerations that there are degrees of redundancy in safety systems to avoid dependence on any one system, and on the premise that a comprehensive equipment maintenance program is carried out.
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l AUG 211979 2-P. T. Y,uo I feel the above conclusion was thht of SSRT Group's. The question of whether the staff should do more work in the future or not, needs to be discussed further.
4.
With regard to my coment No. 3 of the above reference on the use of 7 percent damping for all mechanical and electrical equipment Dr.
Newmark fut that the equipment in the Dresden-2 facility is adequate to resist an earthquake with an SSE values of 0.20 g.
However, he agreed to review the use of 7 percent damping for the future SEP
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plants.
I still feel the use of 7 percent damping for all mechanical and
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electrical equipment evaluation is questionable. The question of whether we are going to continue to see this number for future SEP plants needs to be discussed further.
P. Y. Chen Seismic Review Group Division of Operating Reactors cc:
D. Eisenhut L. Shao R. Vollmer D. Crutchfield V. Noonan C. Hofmayer T. CMng H. Levin i
X. Jabbour H. Lee ATT'ACl1MCd7 l
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NRC FORM 313 (9 76) NRO( 0240 h us e. oovsawes gNT PRINTINS OrFICE4 9878 -826433
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