ML20133B411
| ML20133B411 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 12/30/1996 |
| From: | Bateman W NRC (Affiliation Not Assigned) |
| To: | Mills G AFFILIATION NOT ASSIGNED |
| References | |
| NUDOCS 9701030166 | |
| Download: ML20133B411 (3) | |
Text
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UNITED STATES 4
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WASHINGTON, D.C. 20066-0001 4
4 December 30, 1996 Mr. Glen R. Mills P.O. Box 3393 Mission Viejo, CA 92690
Dear Mr. Mills:
I am responding to the letter you sent to William T. Russell, of the U.S.
Nuclear Regulatory Commission (NRC) on November 4,1996.
In your letter, you i
request that the NRC address nine questions pertaining to the adequacy of the San Onofre Nuclear Generating Station (SONGS), Units 2 and 3 primary containments.
Questiens 2 thru 5, and questions 7 thru 9, have been referred to the NRC's Region IV office, and they will respond directly to you regarding these questions. The NRC staff's response to questions 1 and 6 are detailed i
below.
Question 1 asks if the containment can perform its safety function when the internal pressure caused by a design bases loss-of-coolant-accident (LOCA) ard the largest anticipated seismic loads are applied simultaneously. The answer is yes, it can withstand this load combination.
The containment is designed for all credible loading conditions, and includes the addition of the LOCA load to the design bases earthquake load.
The LOCA load is the design pressure load of the containment, 60 psig, and is greater than the peak calculated pressure occurring as the result of any postulated LOCA or main steam line break.
The design bases earthquake consists of a static equivalent seismic load for which the dynamic effects have been included in its determination.
Question 6 asks if the damaging effects of corrosion on metals used as part of the containment structure had been considered, knowing that the containment may be required to contain the fission products for years after a postulated accident. The answer is yes, it has been considered. The water containing boric acid coming from the reactor coolant system, the safety injection tanks, the refueling water storage tanks, and the boric storage acid storage tank will accumulate in the containment sump.
The maximum boric acid I
concentration, and the corresponding pH value, has been calculated.
To counteract the acidity of the borated water, baskets of hydrated trisodium phosphate have been placed around the periphery of the containment in the region which is flooded during recirculation. After a postulated LOCA, this chemical will dissolve with the incoming borated water, and will maintain the water's pH in the 7 to 8 range. At these ranges of pH values, no significant corrosion of metallic components is expected to occur.
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Mr. Glen R. Mills I trust this information responds to your request.
Sincerely, e
Original signed by S. Bloom for:
William H. Bateman, Director 3
Project Directorate IV-2
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Division of Reactor Projects III/IV Office of Nuclear Reactor Regulation
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Mr. Glen R. Mills,
I trust this information responds to your request.
Sincerely, William H. Bateman, irector Project Directorate IV-2 i
Division of Reactor Projects III/IV Office of Nuclear Reactor Regulation I
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