ML20206D631
| ML20206D631 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 06/17/1986 |
| From: | George Thomas PUBLIC SERVICE CO. OF NEW HAMPSHIRE |
| To: | Noonan V Office of Nuclear Reactor Regulation |
| References | |
| SBN-1120, NUDOCS 8606200125 | |
| Download: ML20206D631 (3) | |
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George S. Thomcs Vice President Nuctect Production Put2c Service of New Hampshire N;w Hampshire Yankee Division June 17, 1986 SBN-1120 T.F. B7.1.3 United States Nuclear Regulatory Commission Washington, DC 20555 Attention:
Mr. Vincent S. Noonan, Project Director PWR Project Directorate No. 5
References:
(a) Construction Permits CPPR-135 and CPPR-136, Docket Nos. 50-443 and 50-444 (b) PSNH Letter (SBN-1074), dated May 29, 1986, "NRC Requests for Additional Information", J. DeVincentis to V. S. Noonan Subj ect:
NRC Requests for Additional Information Diesel Generator Exhaust Stack Missile Protection
Dear Sir:
In discussions with our Bethesda Licensing Office, the Staff requested clarifications concerning the probability values given in Reference (b).
In response to the request, enclosed please find an annotated FSAR page which clarifies the Staff's concern regarding the mean probability value of a tornado missile strike to the diesel generator exhaust stacks. This revision will be incorporated into the FSAR via a future amendment.
Very truly yours,
/
G orge S. Thomas Enclosures cc: Atomic Safety and Licensing Board Service List fhK05000443
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P.O. Box 300 = Seabrook NH O3874. Telephone (603) 474-9521
Dicca Curren, Esquira Patsr J. Mathtwa, Mayor Hsemon & Weica City Hall
'e 2001 S. Strast, N.W.
Nswburyport, MA 01950 Suite 430 Washington,.D.C. 20009 Judith H. Mizner Silvergate, Gertner, Baker, Sherwin E. Turk, Esq.
Fine, Good & Mizner Office of the Executive Legal Director 88 Broad Street U.S. Nuclear Regulatory Commission Boston, MA 02110 Tenth Floor Washington, DC 20555 Calvin A. Canney City Manager Robert A. Backus, Esquire City Hall-116 Lowell Street 126 Daniel Street P.O. Box 516 Portsmouth, NH 03801 Manchester, NH 03105 Stephec E. Merrill, Esquire Philip Ahrens, Esquire Attorney General Assistant Attorney General George Dana Bisbee, Esquire Department of The Attorney General Assistant Attorney General Statehouse Station #6 Office of the Attorney General Augusta, ME 04333 25 Capitol Street Concord, NH 03301-6397 Mrs. Sandra Gavutis Chairman, Board of Selectmen Mr. J. P. Nadeau RFD 1 - Box 1154 Selectmen's Office 4
Kennaington, NH 03827 10 Central Road Rye, NH 03870 Carol S. Sneider, Esquire Assistant Attorney General Mr. Angie Machiros Department of the Attorney General Chairman of the Board of Selectmen One Ashburton Place, 19th Floor Town of Newbury Boston, MA 02108 Newbury, MA 01950 Senator Gordon J. Humphrey Mr. William S. Lord U.S. Senate Board of Selectmen Washington, DC 20510 Town Hall - Friend Street (ATTN Tom Burack)
Amesbury, MA 01913 Richard A. Hampe, Esq.
Senator Gordon J. Humphrey Hampe and McNicholas 1 Pillsbury Street 35 Pleasant Street Concord, NH 03301 Concord, NH 03301 (ATTN: Herb Boynton)
Thomas F. Powers, III H. Joseph Flynn, Esquire Town Manager Office of General Counsel Town of Exeter Federal Emergency Management Agency 10 Front Street 500 C Street, SW Exeter, NH 03833 Washington, DC 20472 Brentwood Board of Selectmen Paul McEachern, Esquire RFD Dalton Road Matthew T. Brock, Esquire Brentwood, NH 03833 Shaines & McEachern 25 Maplewood Avenue Gary W. Holmes, Esq.
P.O. Box 360 Holmes & Ells Portsmouth, NH 03801 47 Winnacunnet Road Hampton, NH 03842 Robert Carrigg Town Office Mr. Ed Thomas Atlantic Avenue FEMA Region 1 North Hampton, NH 03862 442 John W. McCormack PO & Courthouse Boston, MA 02109 d
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&ieluore ta SE.4-112.0 SB 1 & 2 Amandment 59 FSAR May 1986 The air intake and exhaust piping is designed for shop fabrication of spool assemblies to minimize the field installation effort required.
Flanged joints are utilized to facilitate fit-up, and reduce the number of field-welded joints.
The air intake lines have only one field weld, and the exhaust lines have only two field welds.
The flanged joints in the exhaust piping will be visually inspected for leakage during periodic diesel generator testing.
53 Each engine is equipped with a crankcase exhauster to provide positive crankcase ventilation.
The exhauster discharge is piped to a discharge point outside of the diesel generator building.
The crankcase exhauster is not safety related and is not required for operation of the engine.
Failure of.the exhauster does not affect the starting capability of the engine.
The diesel engine exhaust stack has a drip leg, a 12" nominal diameter pipe approximate'ly 2'-9" long, to capture precipitation.
This leg is located in the horizontal piping between the vertical exhaust stack and the exhaust silencer.
A deflector plate will be mounted on the exhaust stack to minimize the amount of precipitation that could enter and accumulate in the exhaust stack.
Gate valves located at the bottom of the drip leg and also l.
in the bottom of the exhaust silencer will be periodically opened to drain the exhaust system. Also, the high exhaust temperatures of 9000F-10000F will quickly evaporate any captured precipitation when diesel engine is running.
The portion of the exhaust stack above the roof is not protected against i
The' stack extends only 2 feet above the level of the roof.
It is further protected by a 60" outside diameter surrounding guide stack which extends 4 feet above the roof.
This low effective target area results in a low robability, calculated as less than 10-6, for missile l
impact.
i 59 Webt VAUAG).
gg Each diesel-generator unit is capable of operating at its maximum rated output under the following outdoor service conditions and for the durations indicated during the following weather disturbances:
a.
Outdoor Service Conditions :
1.
dmbientairintake:
-20 to 1040F 51 2.
Humidity: 20 to 80% (in D.G. room) 20 to 100% (outdoors) 45 I
b.
Weather disturbances:
i 1.
A tornado pressure transient causing an atmospheric pressure reduction of 3 psi in 3 seconds followed by a rise to normal l
pressure in 3 seconds.
A shorter transient (1.5 seconds) will not affect engine operation and output.
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45 l
9.5-45
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