ML20129H378
| ML20129H378 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 05/31/1985 |
| From: | Olson R BALTIMORE GAS & ELECTRIC CO. |
| To: | John Miller Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8506070560 | |
| Download: ML20129H378 (2) | |
Text
n BALTIMORE GAS AND ELECTRIC CHARLES CENTER. P.O. BOX 1475 BALTIMORE. MARYLAND 21203 ELECTRIC ENGINEERING May 31,1985 DEPARTMENT Director of Nuclear Reactor Regulation Attention: Mr. 3. R. Miller, Chief Operating Reactors Branch #3 Division of Licensing U.S. Nuclear Regulatory Comrnission Washingtore, D.C. 20555
Subject:
Calvert Cliffs Nuclear Power Plant Units Nos.1 & 2; Dockets Nos. 50-317 and 50-318 Request to Use ASME Code Case N411
Reference:
BG&E letter from A. E. Lundvall to Mr. 3. R. Miller (NRC), dated April 19,1985.
Gentlemen:
We appreciate your-prompt response to our request for use of the subject code case. We were verbally informed last week that Mr. Kirkwood of your staff has requested additional Information in support of that request. This information is provided below:
Request 1:
Provide a commitment to only use the code case for piping systems analyzed by response spectrum methods and not for piping systems analyzed by time-history analysis methods.
Response
We commit to this condition.
Request 2:
Provide an indication of whether the code case is to be used for new analysis or for reconciliatinn work and support modification.
Response
As indicated in the referenced letter, we plan to use Code Case N411 both for analysis of new piping systems and for reanalysis of existing systems.
Reanalysis of existing systems would include analyses performed to justify elimination of certain pipe supports and snubbers.
Request 3:
Due to the increased flexibility of the piping system, provide a commitment to check all system predicted maximum displacements for adequate clearance with adjacent structures, components and equipment, and that piping-mounted equipment can withstand the increased motion.
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ADOCK O 317 P
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Mr,3. R. Miller May 31,1985
Response
The referenced letter included a commitment to check the increased displacements for interactions.
We will also check piping-mounted equipment.
Request 4:
Provide a commitment that when the alternate damping criteria of the code case are used, they will be used in their entirety in a given analysis and shall not be a mixture of R.G.1.61 criteria and the alternate criteria of the code case.
Response
Regulatory Guide 1.61 is not applicable to Calvert Cliffs. We used 0.5%
damping in the analysis of piping systems. Therefore, we will use the code case criteria, rather than mixing with R.G.1.61 criteria.
Our request for adoption of ASME Code Case N-411 is made in accordance with the provisions of 10 CFR 50.55a, paragraph (aK2Xii). We have determined that use of the this code case will maintain an acceptable level of quality and safety in piping system design,~ comparable to that of the original design requirements specified in 10 CFR 50.55a, paragraph (d)(1).
If you should have any questions, please do not hesitate to contact us.
Very t@u s, C. L. Olson Principal Engineer Nuclear Licensing and Analysis Unit RCLO/BSM/vf cc: D. A. Brune, Esq.
G. F. Trowbridge, Esq.
Mr. D. H. Jaffe, NRC Mr. T. Foley, NRC