ML20239A527
| ML20239A527 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 09/10/1987 |
| From: | Alexion T Office of Nuclear Reactor Regulation |
| To: | Schnell D UNION ELECTRIC CO. |
| References | |
| NUDOCS 8709170404 | |
| Download: ML20239A527 (4) | |
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'l Docket No. 50-483 DISTRIBUTION:
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TAlexion Local POR OGC-Bethesda PDIII-3. r/f EJordan Mr. Donald F. Schnell
'GHolahan JPartlow-l Vice President - Nuclear DWigginton ACRS(10)
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Union Electric Company P0'Connor
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, Post Office Box 149 St. Louis, Missouri 63166
Dear Mr. Schnell:
SUBJECT:
' REQUEST FOR ADDITIONAL INFORMATION RELATED TO THE MAIN STEAM LINE BREAK OUTSIDE CONTAINMENT WITH SUPERHEATED STEAM l
The staff is continuing'itsL review of your submittals-dated April 4,1986 and March 24, 1987. To permit us to continue our review on our current schedule, the information~1dentified in the Enclosure is requested within 45 days of l
your receipt of this letter.
l This request for information affects fewer than 10 respondents; therefore, OMB-clearance is not required under Pub. L.96-511.
Sincerely, rd Thomas W. Alexion, Project Manager Project Directorate III Division.of Reactor Projects
Enclosure:
As stated cc: See next page I
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LA/PDh11-3 PM DRt(-3 P
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Surname: PKpfzer TAl xfo:17tg DWigginton Date:.
-09/g/87' 09/1b /87 09//d/87
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8709170404 870910 PDR ADOCK 05000483 P
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I Mr. D. F. Schnell Callaway Plant Union Electric Company Unit No. 1 cc:
Dr. J. O. Cermack Mr. Bart D. Withers CFA Inc.
President and Chief 4 Professional Dr., Suite 110 Executive Officer Gaithersburg, MD 20879 Wolf Creek Nuclear Operating Corporation Gerald Charnoff, Esq.
P. O. Box 411 Thomas A. Baxter, Esq.
Burlington, Kansas 66839 Shaw, Pittman, Potts & Trowbridge 2300 N Street, N. W.
Mr. Dan I. Bolef, President Washington, D. C.
20037 Kay Drey, Representative Board of Directors Coalition Mr. T. P. Sharkey for the Environment Supervisor, Compliance St. Louis Region Union Electric Company 6267 Delmar Boulevard Post Office Box 620 University City, Missouri 63130 Fulton, Missouri 65251 U. S. Nuclear Regulatory Connission Resident Inspectors Office RRf1 Steedman, Missouri 65077 Mr. Alan C. Passwater, Manager Licensing and Fuels Union Electric Company Post Office Box 149 l
St. Louis, Missouri 63166 Manager - Electric Department Missouri Public Service Commission 301 W. High Post Office Box 360 Jefferson City, Missouri 65102 Regional Administrator U. S. NRC, Region III 799 Roosevelt Road Glen Ellyn, Illinois 60137 l
l Mr. Ronald A. Kucera Deputy Director Department of Netural Resources P. O. Bcx 176 Jefferson City, Missouri 65102 l
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I REQUEST FOR ADDITIONAL INFORMt" Y MAIN STEAM LINE BREAK OUTSIDE CONTAINMENT WITH SUPERHEAT i
CALLAWAY PLANT, UNIT 1 DOCKET N0. 50-483 By letters dated April 4, 1986 and March 24, 1987, the licensee provided a report entitled, "Evaluati:n of Environmental Qualification of Equipment Considering Superheat Effects of High Energy Line Breaks for Callaway Plant and' Wolf Creek Generating Station," and responded to a request for additional in-I formation, respectively. The staff has reviewed this information and, as a result, initiated a telephone conference to obtain additional clarifying infor-mation. The telephone conference occurred on July 2, 1987, and as a result i
the staff is requesting that the licensee provide written responses to the J
following questions:
1.
For all instances where the qualification temperatures of various pieces of equipment (e.g., Main Steam Pressure Transmitter, Main Steam Isolation j
Valve, etc.) may be exceeded as a result of a design basis accident and you have detennined that alternate equipment is available to accomplish the function of the failed equipment, discuss the environmental qualifica-tion status of the alternate equipment.
la.
Is the criteria for using the alternate equipment contained in the plant (s) emergency operating procedures?
2.
'In your evaluation, it is stated that the Main Steam Isolation Valves and the Main Feedwater Isolation Valus are both qualified to a temperature of 450*F; however, the appurtenances have various qualification temperatures.
Our review has found that these various qualification temperatures are as low as 300'F. Note that the staff considers the qualification status of any piece of equipment to be based on its weak link. Please explain why you consider this item to be qualified to 450'F when some of its appurte-nances are qualified to temperatures less than 450*F (e.g., Terminal Blocks 300*F, Limit Switches 342*F Wiring 346 F, Terminal' Lugs 352*F and Conax Seals 420*F).
3.
Explain why the (XLPE) Control Cable, identified in your submittal as qualified to 385'F, is expected to perform its function when its qualification temperature is exceeded.
4.
In the submittal provided by letter dated March 24, 1987, you have compared various equipment items to establish similarity. Although all items may be similar as you have stated, you did not always provide sufficient infor-mation for a reviewer to reach that conclusion (e.g., on page 6 of 27. it is stated, in part, that a thermal lag curve was not specifically developed for a limit switch.
It was assumed that a limit switch housing thermal response would be similar to the response of the solenoid valve solenoid housing (Equipment 1).
It it further stated that this assumption is ap-propriate because the thickness of the limit switch body is equal to the molded solenoid valve solenoid housing. You also referred the reader to a sketch).
4,
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' ForEquipment1(solenoidhousing),youhaveprovidedsomedetail i
information that is appropriate for comparison purposes such as the fabrication material of the housing, density, thermal conductivity, specific heat, thickness and a sketch. However, similar information I
was not provided for the limit switch.
Consequently, for all instances where you have made comparisons similar to the above examples, you must p(rovide all information necessary to reach an independent conclusion i.e., information such as that provided for Equipment 1 in the above example).
5.
In accordance with IEEE Standard 323-1974, a margin of 15'F is required l
when qualifying for temperature in a harsh environment. According to l
infonnation provided for MSIV/MFIV control cable and MSIV/MFIV wiring and 1
I lugs, margins of only 2*F and 6*F, respectively, are indicated. Discuss I
the rationale for your determination that this is acceptable.
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6.
Th( analysis conducted for main steam line break with superheat indicated tha' the qualification temperatures of four items of equipment will be i
exceeded, and an additional two items (identi','ied in question 5 above) do not meet the margin requirement of IEEE 323-1974. These six items are identified in Table 3.4 of your submittal as:
1.
Main Steam Pressure Transmitter Instrument Cable 2.
MSIV/MFIV Wiring and Lugs 3.
MSIV/MFIV Control Cable (Wolf Creek only) 4 MSIV/MFIV Limit Switch 5.
MSIV/MFIV Limit Switch Instrument Cable 6.
J-601A Control Cable Discuss the consequences of the simultaneous failure of all six items.
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