ML20009F396
| ML20009F396 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 07/23/1981 |
| From: | Tedesco R Office of Nuclear Reactor Regulation |
| To: | Abel J COMMONWEALTH EDISON CO. |
| References | |
| NUDOCS 8107310099 | |
| Download: ML20009F396 (5) | |
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TERA DEisenhut
'PDR-Jijt 3 3 ;ggy JYoungblood LPDR Docket Nos.: STN 50-454
-,MRushbrook NSIC and STN 50-455 KKiper TIC
" JSnell ACRS (16)
SHanauer Mr. J. S. Abel RVollmer Director of Nuclear Licensing _
TMurley.
,,,, RMattson Co m a.fealth Edison Company
,RHartfield, MPA P. O. Box 767
... 0 ELD Chicago, Illinois 60690 OIET3)
Dear Mr. Abel:
GStaley
Subject:
Byron Safety Review In the process of our review of the Byron /Braidwood FSAR,.we have identified a need for infonnation regarding the hydrology at the Byron. Station..Our request for additional information is included,as Enclosure 1 to this letter.
In order to maintain our review schedule, we need to have a full response to these questions within six weeks.of. receipt.of this letter.
If you anticipate difficulty meeting this schedule or..if,you need clarification of this request, contact the Byron. Project. Manager, J. Snell at (301)492-8986.
Sincerely, oristnal gened by h I. Todeoco Robert L. Tedesco, Assistant Director for Licensing C
Division of Licensing
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Request for Additional T
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Mr. Losis 0. Del George' Di: -tor of Nuc1c ar Licensing Commonweal th Edison Company Post Office Box 767 Chicago, Illinois 60690 CCS 3
' *Mr. William Kortier Mr. Edward R. Cress Nuclear Sefeguards and Licensing Division Atomic Power Distribution Westinghouse Electric Corporation Sargent & Lundy Engineers P. O. Box 355 55 East Monroe Street Pittsburgh, Pennsylvania 15230 Chicago, Illinois 60603 Paul M. Murphy, Esq.
Nuclear Regulatory Conmission, Region I?!
Isham, Lincoln & Beale Office of Inspection and Enforcement-One First Netional Plaza 799 Roosevelt Road 42nd Floor Glen Ellyn, Illinois 60137 Chicago, Illinois 60603 Myron Cherry, Esq.
Mrs. Phillip B. Johnson Cherry, Flynn and Kanter 1907 S+ stford Lane 1 IBM Plaza, Suite 4501 Rockford, Illinois 61107 Chicago, Illinois 60611 Professor Axel Meyer Deoartment of Physics
~
Northern Illinois University DeKalb, Illinois 60115 C. Allen Bock, Esq.
P. O. Box 342 Urbanan, Illinois 61801 9
Thomas J. Gordon, Esq.
Waaler, Evans & Gordon i
2503 S. Neil Champaign, Illinois 61820 l
Ms. Bridget Little Rorem Appleseed Coordinator 1
117 North Linden Street Essex, Illinois 60935 4
Kenneth F. Levin, Esq.
Beatty, Levin, Holland, Basofin & Sarsany 11 South LaSalle Street Suite 2200 Chicago, Illinois 60603 j
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ENCLOSUR5i.
Hydrologic Engineering Questions Byron Nuclear Station Docket Numbers 50-454/455 i
{371.11 Provide the hydrostatic and hydrodynamic forces that were used for the l(2.4.3.9) st'ructural analysis of the River Screenhouse.
State whether these forces i
were controlling, i.e.,
serve as the design basis.
Provide a discussion i
that describes the combined events (e.g., SPF and OBE, SSE and 25 year L
flood, etc) that' were considered when determining the critical loads for l
the. structures.
Provide the pertinent parameters that were used in the i-analysis of'the most critical combination.
These should include still-water level, wave heights, wind speed, type of wave (breaking, non-breaking,
. etc), fetch length, wave period, depth of water and the building wall that is applicable.
j.
l371.12 Provide details of the canal or channel that connects the River Screen
- (2.4.8) i House to the central river channel. Also provide an expanded rating-i f
curve (at the intake) for flows from 0 to 2000 cfs.
371.13 Provide additional datt and discussion to assure that the intake channel (2:4.8)
(2.4.11) cannot be biccked by either sediment or ice accumulation, especially-1 l
during drought conditions.
Consider a simultaneous occurrence of the 100 year recurrence - 30 day duration drought (sinter and summer) and a 500 year seismic event and other combinations of'a severity similar to that of ANSI N170-1976 (Chapter 9, Combined Events Criteria).
Provide estimates of the Rock River suspended-and bed load concentrations in the vicinity of the intake structure and estimates of normal and maximum ice thicknesses on the Rock River.
Also provide a discussion of the effects of frazzle ice on operation of the river intake.
371.14 Provide detailed cross sections of the River Intake Structure that clearly
( 2. 4.11 )
si.ow the relationship between the invert elevation of the intake floor and/or sump floor, the invert of the dredged channel, the central river channel, minimum river levels and pump submergence requirements.
371.15 Provide the results of the 1978 pumping tests on well W-1 and a (2.4.11) description of well modifications done as a result of the pumping tests.
371.16 You state in Section 9.2.5 that the river screenhou;e base mat elevation 2.4.11)
{9.2.5) 1 is 663.5 feet ms1.
However, in figure 1.2-16 the base mat elevation is shown at elevation 664.0 feet msl.
A resolution of this inconsistency is neces sa ry.
371.17 You have not shown that the ultimate heat sink meets +he criteria of (2.4.11)
(9.2.5)
Position 2 of Regulatory Guide 1.27. " Ultimate Heat Sink for Nuclear Power Plants." You must show that a safety-related water supply will be available during combinations of drought and seismic events, of a severity analagous to that of ANSI N170-1976 (Chapter 9, Combined Events Criteria).,
In your discussion, provide summaries of all analyses, justification of all parameters used and discussions of uncertainties in predicting water 1
levels (including error bands). We are concerned that the elevations of low river flows can not be calculated to precise values because of the judgement involved in selection of roughness coefficients, the quality and quantity of surveyed river cross sectiN s and the unpredictable nature of moveable beds.
Therefore, if the predicted critical low water elevation is within about 1.0 feet of the base slab elevation, then additional justification should be provided to account for all uncertainties in the predicted level.
371.18 In order to assure that the emergency water supply from the mechanical draft cooling towers can meet the criteria of Regulatory Guide 1.27, Position 1, the staff requires you to do either of the following or provide an acceptable alternative:
Validate the predicted tower performance with actual performance data a.
from existing cooling towers of comparable size and type which operate under a range of severe heat loads and environmental conditiuns, or i
b.
Comnit to a pre-operational testing program to be used to validate the predicted tower performance supplied by the manufacturer.
These predicted performance data should be submitted for NRC review at least 60 days prior to the actual testing, and preferably prior to SER issuance.
Indicate.hich of the above approaches will be used, or present a sub'stitute for approval. Describe how you will proceed unoer the chosen approach.