ML20041F112
| ML20041F112 | |
| Person / Time | |
|---|---|
| Site: | Midland |
| Issue date: | 03/10/1982 |
| From: | Jackie Cook CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| 16229, NUDOCS 8203160200 | |
| Download: ML20041F112 (2) | |
Text
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O Consumers power James w cook 0 h h.
Vice President - Projects, Engineersng and Construction General offices: 1945 West Pernadt Roe 1, Jackson, MI 49201 e (517) 7880453 March 10, 1982
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TOC Harold R Denton, Director
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Office of Nuclear Reactor Regulation 4 I N
Division of Licensing na US Nuclear Regulatory Commission Washington, DC 20555 MIDLAND PROJECT MIDLAND DOCKET NOS 50-329, 50-330 FOLLOW-UP RESPONSE TO OPEN ITEM OF PRELIMINARY DRAFT SER 3.6.1 FILE: 0505.805 SERIAL:
16229
Reference:
(A) J W Cook Letter to H R Denton, Serial 14835, Dated 11/12/81
Enclosure:
Follow-Up Response to Open Item of Preliminary Draft SER 3.6.1 Reference (A) responded to the open items of preliminary draft SERs 10.4.9 and 3.6.1.
Enclosed is an expanded response to SER 3.6.1 open item.
Based on the enclosed information, CP Co believes that the MSIV's do not need to be environmentally qualified and the Staff can close out this open item.
Osw /d. 6d JWC/ PEP /fas CC RJCook, Midland Resident Inspect (
RHernan, US NRC DBMiller, Midland Construction (3)
ODParr. US NRC RWHuston, Washington DD S
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oc0382-0745a131 8203160200 820310 PDR ADOCK 05000329 E
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DRAFT SER 3.6.1 FOLLOW-UP RESPONSE Bill Lefave, Auxiliary Systems Branch, has expressed a concern regarding envi-ronmental qualification of the Midland Main Steam Isolation Valves (MSIVs) located within the tornado shielding on the auxiliary building roof. The HSIVs are located within the break exclusion zone which was designed in accordance with Branch Technical Position MEB 3-1, Rev 0, dated 11/24/75 and, as a result, breaks need not be postulated. The NRC agreed with this position in a meeting on September 13, 1978, which was prior to the addition of the tornano shielding.
The addition of the tornado shielding does not significantly change the environment to which the MSIVs would be exposed. Preliminary calculations performed for effects of pressurization within the tornado shielding, showed a peak pressurization of 0.1 psig on a global scale after a complete severance of an 8 inch diameter branch line coming off of a main steam line. The pressure buildup was small because of the large vent area of the tornado shielding. This would also tend to minimize teeperature peaks after a line break.
In addition, the actuators and their associated electrical components are enclosed in steel housings which would further reduce the effects of tempera-ture and pressure transients.
oc0382-0745b131