ML19220B693
| ML19220B693 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 04/30/1975 |
| From: | Harold Denton Office of Nuclear Reactor Regulation |
| To: | Moore V Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7904270224 | |
| Download: ML19220B693 (5) | |
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m 3 0 E5 NRR-RDG SA3-RDG V. A; Moore, Assistant Director for Light Water Reactors, Group 2 HTDit0 LOGIC ENGDT.ZRI5G POSITIONS (Q-2)
PLANT NA'C: Three Mile Island - Unit 2 LICEU3ING STAGE: CL DOCIET NU:GER:
50.-320 RESPOUSI3LE BRANCH: LWR 2-2 REQUESTZD COMPLETION DATE: April 25,1975 RE7Iri STATUS: Hydrologic Engineering Section (SA3) - Awaiting Responses Enclosed are hydrologic engineering positions (Q-2) for the subject plant, prepared by T. L. Johnson and "J.
S. Sivins for your transnittal to the applicant. Our sajor concerns are with the ef fect of local intense precipitation, the present state of the riprap protection for the dikes, and flood protection requirer.ents for safety related buildings.
A draf t copy of these questions was provided to the LPM on April 29, 1975.
Or%$ni Tced by H. R. Dent:ri Harold R. Denton Assistant Director for Site Safety Division of Technical Review Office of Nuclear Reactor Reguistien Znclosure:
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81-184 1
HYDROLOGIC ENGINEERING POSITIONS (Q-2 THREE MILE ISLAND UNIT 2 DOCKET NO. 50-320 m
81-185
321.01 RSP It is our position that the roof drainage systems of safety-related (2.4.2) buildings are inadequate. Your response to Question 32.2.1 is not complete. You have nqt documented that the roofs will safely store or discharge.the local Probable Maximum Precipitatica (PMP).
You will be required to redesign your roof drainage syeten, unless it can be documented that:
1.
the roofs will withstand the loading of the total PMP, or 2.
th: roof drainage syates will safely dischcrge the PMP witt.out threat to safety-related components, systems,
- and structures.
Provide the bases for your conclusions.
321.02 RSP
.t is our position that your site drainage facilities are (2.4.2) inadequate. The potential water surface elevation at the site due to a local FMP may be as high as elevation 301 =si, assuming coincident blocking of the drainage culvert by debris.
You have not shown that emergency operating procedures will be unaffected by this level or that a flow path can be maintained through the drainage culvert. You will be required to redesign your site drainage facilities, unless it can be documented that:
1.
proposed e=crgency =easures. assure maintenance of a flow path through the outlet culvert, or 2.
emergency =casures required for plant shutdown (such as necessary transportation to and from buildings, placing of flood barriers, etc.) are not affected by the maxi =um water level, and adequate time is available to shutdcwn the plant, if necessary.
321.03 RSP It is our position that the flood protection provided at (2.4.3) safety-related buildings is inadequate.
'Je conclude that the maximum wave runup (coincident with PMT) is approximately 4 feet, which will overtop flood barriers to be placed.
- Further, you have not dorutented that safety-related facilities are adequately protected against the static and dynamic effects of wave action, as requested in Question 32.2.5(7). You will be required to redesign applicable poritions of your flood protection, unless.it can be documented that, due to.their location, the various flood barriers 2nd structures are not susceptible to the
=aximus runup and wave forces.
In docu=enting the above, substantiate your design by providing the effee ive fetch diagrams, and discuss the average depths of water used in your computation of wave hei; hts and periods.81-186
i Provide your co puted valves of wave heights, periods, and wave runup at safety-related structures and at the various locations where flood barriers are placed.
321.04 RSP Your response :o Questica 32.2.4 1s not adequate. We do not (2.4.9) concur that annual sedicentation =enitoring following the
" spring floods" is adequate to assure the uninterrupted availability of the ultimate heat sink. Further, we have insufficient infor=ation to conclude that the heavy sedimentation you experienced at the Unit 1 intake is solely attributable to the removal of the Unit 2 cofferlas.
It is our position that you should:
1.
commit to perform sedimentation =cnitoring not less than once each 6 =enths, 2.
in lieu of ite: 1, cocci: to perform sedimentation monitoring during the recession of floods which were equal to or greater than 200,000 cfs (approxi=ately the mean annual flood as specified by the Harrisburg gage record) and following the spring floods, regardless of =agnitude.
3.
describe your proposed " sounding" =ethods and areal extent of coverage. With regard to the latter, a sufficient width of the middle channel should be monitored to assure the intake structure is not being segregated froa the =ain channel, which may shif t within the confines of the river b anks.
321.05 RSP Your response to Question 32.2.71s not clear.
It is our position (2.4.9) you should:
1.
document that elevation 271 ft MSL at the intake structure corresponds to a flow of 430 cfs through the middle channel and identify and substantiate the bases for the assumed nature and location of the " hydraulic diversions at the upstrea end of the middle channel".
2.
in lieu of 1, provide 2n alternate source of e=ergency cooling water supply.
321.06 RSP Your response to Question 32.2.5 is inadequate.
It is our position (2.4.10) you should:
1.
. document that access via the bridge will not be required during flood-induced emergency shutdown or to implement emergency measures, 2.
in lieu of 1, provir'.e a plan for alternate means of a' cess e
to the island.81-187
~ 321.0 7 RSP It is our position that the present state of the erosion (2.4.10) protection provided for the dikes is inadequate. At many locations, we are aware of i= proper and/or inadequate placement of and damage to the riprap. The follcwing will be required as soon as possible:
1.
Co==1: to adequately r slace and repair any erosion protection which has buen da= aged since originally placed, or which otherwise does not teet your design bases.
2.
Place erosion protection at locations where required.
3.
Document that the erosion protection (size, thickness,
gradation) is adequate by showing the design basis channel velocities and wave heights which may exist at specific locations and the ability of the erosion protection to resist that velocity and wave height. Provide the bases for and the results of your cocputations.
4.
Provide the date at which items 1-3 will be acco=plished.81-168
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