ML20051L707
| ML20051L707 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 05/10/1982 |
| From: | Devincentis J PUBLIC SERVICE CO. OF NEW HAMPSHIRE, YANKEE ATOMIC ELECTRIC CO. |
| To: | Miraglia F Office of Nuclear Reactor Regulation |
| References | |
| SBN-270, NUDOCS 8205170319 | |
| Download: ML20051L707 (3) | |
Text
PUBLIC SEAVICE seAnaOOK STATION Enginsedng Office:
Companyof New Hampshire 1671 Worcester Road Framinoham, Massachusetts 01701 (617) - 872-8100 O
May 10, 1982 g
SBN-270 Q
RECElygg
-3 T.F. B 7.1.2 f,gy IIIf($5 United States Nuclear Regulatory Commission Id Washington, D. C. 20555 9
Attention:
Mr. Frank J. Miraglia, Chief Licensing Branch #3 Division of Licensing deferences:
(a) Construction Permits CPPR -135 and CPPR-136, Docket Nos. 50-443 and 50-444 (b) USNRC Letter, dated February 12, 1982, " Request for Additional Inf ormation," F. J. Miraglia to W. C. Tallman (c)
PSNil Letter, dated March 12, 1982, " Response to 410 Series RAIs; ( Auxiliary Systems Branch)," J. DeVincentis to F. J. Miraglia Su bj ec t :
Response to RAI 410.31; (Auxiliary Systems Branch)
Dear Sir:
We have enclosed a response to the subject <AI which ycu forwarded in Ref erence (b).
This was not included in the Reference (c) responses.
Very truly yours, YANKEE ATOMIC ELECTRIC COMPANY
- /
A-o(; J. DeV centis Project Manager Enclosure Q\\
i320 51 W 3 /7
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e SB 1 & 2 8
Verify that the compressed air furnished to operate safety-related equipment meets the requirements of ANSI MC 11.1-1976, (ISA-S7.3).
In order to assure continuous reliable functioning of compressed air operated valves, provide a technical specification or procedure to require testing of the instrument air quality. Describe the procedures to be followed to detect and correct degradation of the instrument air quality and the limits on degradation from the ANSI standard MC-11-1 which will be imposed on the air quality.
RESPONSE
Each of the elements of the Quality Standard for Instrument Air, ISA-S7.3, is addressed below:
4.1 Dew Point (at line pressure)
Since part of the plant instrument air system is exposed to the outdoor atmosphere, element 4.1 of the quality _ standard requires that the dewpoint of the instrument air at line pressure be at least 18 F below the' minimum outdoor temperature at the site.
Per the Service Environment Chart, F-300219, the minimum outdoor temperature at the site is 0 F.
Therefore, the dew point at line pressure r2st be no greater than (-) 18 F.
The outlet air dewpoint of the instrument air dryers at the instrument air header pressure is (-) 40 F.
For the containment instrument air system, which is fully enclosed and, therefore, does not come in contact with the outdoor atmosphere, the applicable minimum temperature is the minimum temperature inside containment, 50 F per the service environment chart.
Therefore, the dryer outlet dewpoint temperature should be 32 F maximum.
The refrigeration dryer's outlet pressure dewpoint is 65 F below the dryer inlet temperature.
The dryer inlet temperature is specified as 105 F, which sets the worst case dryer outlet dewpoint at (+) 40 F.
The two temperature bounds, 50 F minimum containment temperature and 105 F specified maximum dryer inlet temperature, are operational extremes which, taken individually, form the basis for in-continment equipment selection.
But the two extremes would never both be experienced within a short period of time, so it is not reasonable to apply both extremes simultaneously to a design evaluatioc, By depressing the dewpoint 40 F below the dryer inlet temperature, the containment instrument air dryers provide adequate confidence that the containment instrument air system will remain ' dry'.
4.2 Particle Size Element 4.2 of the quality standard requires that the maximum entrained particle size at the instrument be three micrometers.
The dual filters provided in each IA subheader and the filter / regulators provided at each d
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air user both have approximately 40 Mic filtration (for both the plant and containment UL systems).
This degree of filtration is in compliance with standard industry practice dnd with the practices of the manufacturer's. of pneumatic instruments and
' valve actuators, who supply 40 micron filter / regulators as standard accessories and is considered acceptable for our application.
4.3 Oil Content Element 4.3 of the quality standard requires that thi maximum condensible hydrocarbon content of the instrument air (under normal cperating conditions) not exceed 1 ppm either on a weight basis or on a volume basis.
The compressors are oil-free (there is no infiltration of lubrication i
oil), as are the dryers.
4.4 contaminants The quality standard requires that the instrument air be free of ccrrosive
-)
or otherwise hazardaus contaminants. The two instrument air systems (plant and containment) are fed compressed air from (1) the turbine b1dg.
and (2) containment. There should be no detrimental gaseous contamination in these ihtake areas. Particulate contamination, should it become entrained in the air stream, would be removed by the filter in the system. Procedures-for monitoring the instrument air quality will be available three months before fuel load. Any technical specifications will be developed following the guidance in NUREG 0452, Standard Technical Specifications.
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