ML20213D863
| ML20213D863 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 10/30/1981 |
| From: | Lear G Office of Nuclear Reactor Regulation |
| To: | Schwencer A Office of Nuclear Reactor Regulation |
| References | |
| CON-WNP-0414, CON-WNP-414 NUDOCS 8111060048 | |
| Download: ML20213D863 (6) | |
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007 3 0 1531 Docket Files HGEB Reading l
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Docket flo. 50-397 a
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i!E!!0RAI'Dlff FOR:
A. Schwencer, Chief
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George Lear, Chief I!ydrologic and Geotechnical EngineerintfGrancli Division of Engineering SUOJECT:
IlYDROLOGIC Ef!GII EERIt:G SAFETY QUESTI0t!S FOR W!!P-2 PLN T Plant !!ane: !!i:P-2 Licensing Stage: CL Docket !!unt cr:
50-397 Enclosed are F!ydrologic Engineering Safety Questions for your transmittal to the Applicant. These questions were prepared by Gary B. Staley of the flydrologic Engineering Section, Phone 20003, and were discussed with the applicant during the site visit on October 6,1931.
Original signed by George Lear Gecrge Lear, Chief liydrologic and Geotechnical Engineerinq Uranch Division of Engineering
Enclosure:
As stated cc: w/o enclosure R. Vollner R. Tedesco 9,\\
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w/ enclosure F. Schauer C. Auluch G. Staley it. Fliegel L. I!eller e111060048_B1103 D. Gupta C ADOCK 05000397 R. Jackson f.*
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Hydrologic Engineering Section Safety Questions WNP-2 371.15 We have previously requested information on the design basis rainfall for the roofs of safety related buildings (Q371.2). Your response to that request did not fully address the question. The purpose of this
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request is to allow the NRC staff to verify that the roofs of safety related structures can withstand the stresses resulting from Prob 6ble Maximum Precipitation (PMP) and other normal loads that are combined with PMP.
Past practice indicates that the applicant generally has two choices as follows:
(1) Where the structural distress level (safety related roofs), in terms of ponded rainfall depth combined with other normal coincident loads, exceeds the height of the parapet walls, it is acceptable to provide the structural distress level and indicate that since this level exceeds the height of parapet walls, PMP is not the controlling design basis event.
(2) Where the structural distress level (as previously defined) for the roof of a safety related building is below the level of the parapet wall, then the applicant must provide sufficient data for the NRC staff to independently determine the maximum depth of ponded water (PMP) and whether it is less than the structural distress level. The minimum data required is:
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, a.
Area of confined roof.
b.
If credit is taken for roof drains provide details of drains and justification for precent blockage assumed. Consider ice and other possible debris, c.
Elevation of roof and parapet wall.
d.
Number, size and elevation of scuppers, t
e.
Probable Maximum Precipitation rate and bases.
f.
Where the above information is provided on drawings, they should be unreduced, reduced drawings are generally not legible.
371.16 Reference previous questions numbers 371.1 and 371.8. Your responses did not provide sufficient information.
Provide a unreduced post-construction topographic map (s) that clearly shows site drainage features including:
(1) Road and railroad grade elevation, (2) invert elevation and size of drainage ditches, (3) culvert invert elevations, cross-sectional area, type, length and inlet and outlet features, (4) where drainage water is temporarily ponded (maximum level close to plant grade) provide the area-capacity information for the storage area, and (5) show the drainage sub-areas, direction of flow, drainage area, hydrograph and peak discharge and method of computation.
1 371.17 The groundwater pathways analyses in th'is section are inconsistent both (Section 2.4.13.3) within the section and with other parts of the FSAR and ER.
a.
The analyses for the two cases is impossible for the staff to follow because you gave no details on the physical situation.
For example in the "first case" analysis, it is not clear whether you assumed saturated or unsaturated flow in the region above the water table.
In the second case analysis the physical situation you envision is not at all clear.
Furthermore/neither case appears to be directly solved by the equations on page 2.4-40, (Amendment 13).
Please elaborate extensively on the physical situations and how they were modeled, b.
Values of physical parameters of the groundwater flow disagree widely with reported values in other parts of section 2.4.13 of the FSAR and 2.4.2 of the ER.
For example, you used an effective porosity of 0.2 in your transport analysis. The ER, page 2.4-8, Amendment 2, estimates that available porosity of the glaciofluvial sediments is between 0.048 and 0.11, and the average effective porosity is 0.09.
The values of permeability of 50.2 ft/ day which you used appear to be much too low. Values of permeability for the glaciofluvial sediments are reported elsewhere in the FSAR and ER to range from 1,200 to 12,000 ft/ day.
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, ~. The actual migration of chemical and radioisotope plumes from fuel reprocessing at the Hanford reservation strongly indicates that ground water movement is substantially greater than your estimates.
A rough estimate of plume movement based on figure 2.4 indicates that your estimates of ground water movement are too low by at least an order of magnitude. Ground water m'ounding at the disposal operation would account for only a small fraction of the plume movement.
Please revise your migration estimates to take these data into account.
371.18 Ultimate Heat Sink 1.
In order for the staff to perform an independent analysis, please provide the following information on nozzle characteristics:
a.
drop diameter cistribution at operating pressures; b.
pattern of drops leaving spray nozzles (e.g., heig'ht, width, density) for range of pressures.
2.
Provide results of pre-operational testing of sprays performed at the site so far.
3.
Did the design basis of the spray ponds consider the effects of volcanic ash on the reduction of pond volume or the operation of pumps? Please elaborate.
Provide a commitment on operational (or pre-operation) testing of the i
spray ponds to verify performance characteristics. Although the staff can make a preliminary determination of acceptability based on the manufacturers 1
suggested performance criteria, it is necessary to verify the performance 1
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parameters under load. The Hydrologic Engineering Section is especially concerned with the therm'al and water use characteristics. The seepage rates will also have to be verified unless it can be shown that the make up capability can survive all natural events and combinations thereof.
t 371.19 Provide the leakage rates that were determined during initial testing of the spray ponds. How do these rates compare with the rates used in the Battelle study? Provide an analysis that shows the maximum groundwater rise at the corner of the diesel generator building that would result from the maximum leakage rate observed during preliminary testing of the spray ponds. Provide the permeability and specific yield (effective porosity) of the compacted plant fill and other parameters used in your analysis. Since more than one aquifer (plant fill and glaciofluvial) is involved, a sensitivity study might be appropriate.
I 371.20 Effect of Failure of Circulatina Water System Pipe on Design Basis Groundwater Consider the failure of the circulating water pipe at its c'losest proximity to a safety related building. Would the backfill around the safety related building be saturated for a temporary period? If the answer is affinnative, analyze the affects under dynamic loading conditions associated with the SSE.
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