ML19221A966
| ML19221A966 | |
| Person / Time | |
|---|---|
| Issue date: | 03/31/1979 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| References | |
| NUREG-75-087, NUREG-75-087-02.4.11, NUREG-75-87, NUREG-75-87-2.4.11, SRP-02.04.11, SRP-2.04.11, NUDOCS 7907120077 | |
| Download: ML19221A966 (8) | |
Text
gn arcq NU R EG-75/087 f
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- t U.S. NUCLEAR REGULATORY COMMISSION
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. 7 STANDARD REVIEW PLAN g
i OFFICE OF NUCLEAR REACTOR REGULATION SECTION 2.4.11 LOW WATER CONSIDEF.ATIONS REVIEW RESPONSIBILITIES Primary - Hydrology-Metecrology Branch (H"B)
Secondary - None I.
AREAS OF REVIEW The purpose of this section of the applicant's safety analysis report (>AR) is to identify natural events that may reduce or limit the available cooling water supply, and to assure that an adequate water supply will exist t". operate or shut down the plant, as required.
Depending c, the site, the areas of review include 1.
The worst drought considered reasonably possible in the region.
2.
Low water (setdown) resulting from surges, seiches, or tsunamis.
l 3.
Lcw water resulting from i t. i ng.
4.
fhe effect of existing and proposed water control structures (dams, diversions, dam failures, etc.).
5.
The intake structure and ' imp design basis in relation to the events described in i
SAD Sections 2.4.11.1, 2.4.11.2, 2.4.11.1 and 2.4.11.4.
6.
The use limitations imposed or under discussion by federal, state, or local agencies 9
authorizing the use af the water.
7.
The range of water supply required by the plant, including rinimum operating and shutdown flows, compared to availability.
8.
The ef fects of potential blockage of intakes by sediment and littoral drif t.
l II.
ACCEPTANCE CRITERIA Acceptance is based princips ly on the adequacy of the intake desigo basis for safe shutdown, cooldown (first 30 days), and long-term cooldown (periods in excess of 30 days) during adverse ratural phennmena or other events which rc.uire shutdown. Where the specific design bases preclude plant operation during severe hydrologically related events, sufficient warning time must be demonstrated so that the plant may Le shut down during or in advance of adverse events eithout causing potential damage to safety-related facilities. In cases where sufficient warning time to permit advance shutdown is con-sidered necessary to protect safety re!aL'i components, an item in the plant Technical Soecifications will be required.
i/;5 337 USNRC STANDARD REVIEW PIAN
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R.g 70071200 77
SAR Section 2.4.11.1 (Low Flow in Rivers and Streams): For essential water supplies the low flow / low level design for the primary water suppi) source must be based on the probable minimum low flow and level resulting from the most severe drcught that can
.aion.
The low flow and level design bases reasonably be considered possible for for operation (if different than the c-es for essential water requirements) should be such that shutdowns caused by i w quate water supply will not cause frequent use of emergency systems. In cases where a common source of cooling water for operation and safety is provided, and where operation can affect minimum levels required for safety, the system will be acceptable if technical specifications are provided for shutdcwn before the ultimate hea. sink can be aaversely affected.
SAK Section 2.4.11.2 (Low Water Resulting f rom Surges, Seiches or Tsunamis): If the site is susceptible to such phenomena, minimum water levels resulting t' setdowr ( s or'e time s called runout or rundown) f rom hurricane surges, seiches, and ts inis must be higher than the intake design basis for essential water supplies, for co1stal sites, the appro-priate probable maximum hurricane (FMH) wind fields must be postu!ated to give maximum winds blowing offshore, thus creating a probable minimum surge b sel.
Low water levels on inland ponds, lakes, and rivers due to surges must be estimat<J from probable maximum winds oriented away from the plant site.
The same general analysis methods discussed in SRP Sections 2.4.3, 2.4.5 an1 2.4 6 are applicable to low water estimates due to the various phenomena discussed.
SAR Section 2.4.11.3 (Historical Low Wator): If historical flows and levels are used to estimate aesign values by inference from frequency distribution plots, the Gata used must be presented so that an independent determination can be made.
The dat and methods of the National Oceanic and Atmospheric Administration, United States Geologic Survey, Soil Conservation Service, Bureau of Reclamation, and the Corps of Engineers are accep'.able.
SAR Section 2.4.11.4 (Future Controls): This section is acceptable if water use and dis-charge limitations (both physical and legal), already in effect or under discussion by responsible federal, regional, state, or W al authorities, that may affect water supply at the plant have been considered and are '
tiated by reference to reports of the appronriate agencies. The most adverse possia m effects of these controls must be shown and t ren into account in the Jesign basis to assure that essential water supplies are not likely to be affected adversely in the future.
SAP Section 2.4.11.5 (Plant Requirements): Acceptance is based on the fallowing required information:
1.
Minimum essential cooling w1ter flow rates and levels must be presented (or cross-referenced) and stown to be ?ess than the probable minimur low flows and levels from the applicable sources of supply.
2.
Maximum watar requirements for normal operation must be presented and (if applicable) shown to be less than the water available under all likely conditions from the sources of supply.
Rev. 1 2.4.11-2
SAR Section 2.4.11.6 (Heat Sink DepenJability Requirements): The required data and information are thnse necessary to determine that the facility meets the criteria of Requ!. tory Guide 1.2/.
The analyses will be considered complete and acceptable if the following are adequately addressed:
1.
The initial water inve.. tory must be sufficient for sFutdown and cooldawn of the plant 2.
Water losses (such as stepage, drif t, and evaporation) must be conservatively esti-ma'ed, as suggested in Regulatory Guide 1.27.
3.
The design basis hydrometeorology (temperature, dewpoint, etc. ) must be as conserva-tive as the criteria of the guide (see 59P section 2.3).
4.
The limit on the heat sink return water temperature must be less than the maximum allowable cooling water ir.let design t emperature.
5.
The heat sink intakes are located such that no potential exists for blockage by littoral drift and/or rediment that would decrease water suppl, below minimum required levels.
III. REVIFW PROCEDUR[S Minimum plant requirements (water level and flow) that are identi f ied in SAR 5ec tions 2.4.11. 5 or 9.2.5 are compared to the estimated minimum weter levels and flows give, in Section 2.4.11.1.
If normal operation is not assured at the minimum water supply cunditions, and loss of normal operation capability cae adversely affect safetv-related components, estimates of warning time are reviewed to assure that shutdown or cc iversion to alternate water sources can t>e accomplishod prior to the trip.
For such cases, emergency operating procedures are required, and are reviewed to assure that they are cansistent with the postulated conditions. The analysis of the dependability of the ultimate heat sink is reviewed and the conclusions are provided to the Auxiliary Systems Branch (ASB) and fower Systems Branch (PSB). Determination of the dependability of the ultimate heat sink is accomplished by using Regulatory Guide 1.27 as a standard of comparison.
Each source of water for normal or emergency shutdown and conldown, and the natural phenomena and site related accident design criteria for each should be identified. A systems analysis is first undertaken of all water supply sources to determine the likeli-hood that at least one source would survive (1) the most severe of each of the natural phenomena; (2) site related accident phenomena; and (3) reasonable comLinations of less severe natur'l and accident phenomena. Second, arbitrarily assumed mechanistic failures of water supply strectures and conveyance systems are postulated and the systems analysis repe_ed, to assure that the fai sre of one component will not cause failure of the antire system.
These analyses are coordinated with the ASB and PSB rev;ew of the ultimate eat sink and related c'oling systems, to avoid duplication. Operatine *ules for each sortion of the system are :scertained to determine the amount of water that can be assumed available in the event o' normal or accidental shutdown.
If there is evidence of potential structural or mechanical effects, the Structural Engineering Branch (SEB) or Mechanical Engineet ing Branch (MEB) will be requested by HMS to ascertain whether the ef fects are properly considered in the structural or mechanical design bases for the plant. Consul a-9 tions witt the Meteorology Section of HMB, the Geosciences Branch (GB), the Accident Analysis Branch, the Structural Engineering Branch, A5B and PSB are undertaken where dasign criteria are not firmly established, p* f.
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Y"V-I 2.4.11-3
Estimates of water loss due to drift, evaporation, and blowdown are evaluated based on observed severe hydrometeorological measurements at similar locations (coordinated with the Meteorology Section of HMB).
If independent analyses are m emed necessary, computer programs such as HEC-2 (Water Surf ace Profiles), HEC-3 (Reservoir System Analysis), and Ht.C-4 (Monthly Streamflow Simulation) are utilized.
The potential for sur-s in intake sumps (i.e., seiching in intake structures and surges in intake pipes) that could cause adverse ei.ects are reviewed to asst.e that the ef fects have been properly incorporated for the intake derign. The potential for adverse hydro-dynamic effects of a trip of the intake pumps is evaluated based on potential surges in intake sumps.
For multiple purpose (normal opera' on, normal shutdown, and emergency shutdown) water supply systems, the primary portion of the system is first reviewed to determine that the water supply will be maintained at minimum volume requirements at all times. The secondary portion of the system is then reviewed to determine whether an adequate emergency water supply can be expected to be available during operating conditions such as the regional drought of record (flows must be adjusted for historical and potential future effects).
If not, the applicant is requested to provide a technical specification requiring plant shutdown at the point where an adequate shutdown w3ter supply is still assured.
Institutional restraints on water use, such as limitations in water usa and discharge permits, are reviewed to assure the plant will have an adequate supply and not exceed limitations imposed upon operation. If a conflict is foreseen, the applicant is regeested to either obtain a variance or make a design change to accommodate the limitation.
The potential for blockage of the intakes by littoral drift and sediment is reviewed to assure that the intakes are located and sized to prevent blockage which would preclude use of the safety related water supply. Applicable liter ture describing historic sediment accumulations in the site region is reviewed to determita if mitigative measures are required to protect safety-related facilities. Independent estimates of " worst case" buildups will be nade using statistical or deterministic techniques.
For plants usin; rivers, minimum design service water levels are compared with asymtatic
% trapolations of low flow frequency curves which have been corrected for historical and potential future effects. For ocean or estuary plants, design low water levels are compared with probable maximum hurricane and tsurami-induced low water levels. For Great Lakes plants, design low water levels are compared with minimum historical levels coinci-dent with probable maximum surge or seiche-induced low water levels.
If the ultimate heat sink system is not capable of continued long-term water supply under the criteria in Regulatory Guide 1.27, or the above considerations, the system will be reviewed in two parts; short-term capability and long-term capability. For short-term cepability, the ASB, PSB, and the Licensing Project Manager (LPH) will be informed if the independently-estimated supply appears to be less than 30 days.
The applicant will be asked to determine whether sufficient personnel and equipment can safely be made available Rev. 1 2.4.I' 4 7 -
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to switch water supply so cces in the event of an accident. If emergeacy procedures are required to obtain the use of alternate water supplies, the applicant's water supply sources and procedures will be reviewed with ASB, PSB, and the LPM to determine that there is continuity of water supply.
The time period for which a highly dependable water supply would be available it compared with the time required to obtain water from an alternative supply, and the natural or accident environmental conditions which could prevail.
For long-term water supply capability, different sources and means of obtaining water may be required because of the limited capability of a "short-term" supply.
In those cases where dif ferent sources are necessary to assure the long-teim plant heat removal ca;ea-bility, the alternative souices and the means of supplying water from the sources to the plant should be identified. Any plant design provisions nocessary fnr such situations
<hould also be described or a reference provided to other SAR sections for the descriptions fmergency means 70r obtaining long-term water supplies will he judged on the basis of the time required to obtain such supplies, natural or accident phenomena likely to prevail or to have caused the need for such s.pplies, and the depenJability of the supply itself.
IV EVALUATION f!N)INGS f or construction permit (CP) reviews the findings will summarize the applicant's and staf f's estimates of the design basis minimum water flows and levels.
If the applii..nt's estimates are no more than 5% less conservative than the staff's estimates, staff concur-rence in the applicant's estimates will be stated.
If the applicant's estimates are more than W less conservative and if the proposed plant may be adversely affected, a statement of the staff's position (bases) will be made.
A similar finding on the design bases for the ultimate heat sink will be made.
If technical specification requirements are needed to astare an adequate supply, they will te indicated in the CP statement and required for operation.
For operating license (OL) reviews of plants for which detailed low water reviews were done at the CP stage, the CP conclusions will be referenced.
In addition, tne results of a'
'iew ta reaf firm the low water design trases will be noted.
If no changes have oeen made to the ultimate heat sink design since the CP review, the cor.rlusicos of the CP will be referenced. However, f or both the low water cousiderations and the ultimate heat sink, an evaiuation will be made during the OL review to assure that the design bases have been properly implemented. The availability of long-term water supply will be noted.
If no low water and ultimate heat sink review was undertaken at the CP stage (of the scope described), this fact will be nc'ed also.
A sample CP stage statament follcws:
"The applicant proposes two sources of water supply; grounde ter and the adjacent A River.
2.4.11-5 Rev. I
" Groundwater would be used for make up to the essential service water cooling towers, for potable water su;)plv, and for demineralizer water.
The applicant estimates the demineralizer w ald require about 825 gallons per minute (gpm) for the first several months and an average rate of 425 apm thereafter. Petohle water requirements are estimated at about 10 gpm.
"The, ?iver is to provide the principal source of cooling water.
The applicant estima.es the maximum water requirement for the plant will be 107 cf s.
Of this, 61 c f s would be consumptively used and 46 ct s would be re' rned to the A River.
The historical recorded low flow in the A River in the site i>qion was about 500 cfs at the B gage on September 14, 1958 and about 440 cfs at the ~ qage on August 20, 1934.
The applicant estimates the comparable low flow at the sit to be 400 cfs.
Assuming breaching of D Dam five miles dowastream, the low flow we.ld result in an estimated water surface elevation of o64 ft MSL.
" Emergency cooling sources and atsociated principal facilities comprise the A River, oroundwater, the river screenhouse, the essential service coolinci tors, gruand-water well(s) and attendant distrit.ution systems.
The river screenhouse is to be a seismic Category I facility and was initially proposed to be protected from flooding up to the Standard Project F lood (SPF ).
Groundwater wells, Im ated at the plant site, are above estimated PMF water levels.
The applicant p poses to use groundwater for make-up to the essential service towers whenever the A Riser, screenhouse, cr piping is unavailable. Lctimated groundwater use would be 160J gpm.
At the staff's request the applicant reconsidered the floed design basis for the river screenhouse f or relatively long periods of time when the A River could be higher t'.n a SPF and an earthquake could prevent water from being available from wells. The applicant subsequently upgraded the flooj design basis for the screenhouse to a Probable Maximum flood, and concludes the proposed facilities meet the suqqested criteria of Regulat ory Guide 1.21 - Ultimate Heat Sink. We concur.
V.
REFERENCES 1.
L.
R. Beard, " Methods for Determination of Safe Yield and Comper.sation Water from Storage," Seventh International Water Supply Congress, Barcelona, Spain (1966).
2.
L. R. Beard, " Statistical Methods in Hydrology," Corps of Engineers (1962).
3.
- 8. R. Bodine, " Storm Surge on the Open Coast: Fundamentals and Simplified Prediction, Technical Memoran%m No. 35, Corps of Engincers Coastal toqineering Research Center, May 1971.
4.
D.
K. brMy, et al., " Surf ace Heat Exchange at Power Plant Cooling Lakes," EEI Publication 6996!, Edison Electric Institute, New York, Nov. 1969.
5.
V. T. Chew (ed), " Handbook of Applied Hyure May," McGraw-Hill Book Company, New York
~
(1%4).
l 0 (,)
)Y'n-)
pey. 1 2.4.11-6 i
6.
J. E. Edinger and J. C. Geyer, " Heat Exchinge in the Environment," FEI Publication 69-902, Edison Electric Institute, New York, June 1965.
6A.
J. E. Edinger, et at, " Generic Emergency Cooling Pond Analysi," prepared for U.S.
Atomic Energy & mmitsion under Contract No. Al( l l-1 )-2224 ( 19 72).
7.
G.
M.
Fair, et al., "Witer and Wastewater Enlineering," Vol. 1 John Wiley & Son Inc., New York (1966).
8.
" Scientific Hydrology," Ad Hoc Panel on Hydrology, federal Council for Science and Technology, Washington, D.C., June 1962.
9.
M.
B. Fiering, and M. M.
Hufschmidt, " Simulation Techniques for Design of Water-Resource Systems," Harvard University Press, Can. bridge, Mass.
(1966).
10.
R.
K.
.nsley, et al., " Hydrology.'or Engineers," McGraw-Hill Book Company, New York (1958).
11.
R.
K.
Linsley and J. B.
Franzini, " Water-Resources Engin(oring," McGraw-Hil! Book Company, New York (1964).
12.
A. Maas, et al.
" Design of Water-Resourc es Syc tems," Harvard University Press,
Cambridge, Mass. (1962).
13.
G.
W.
Platzmir. "The Dynamical Prediction of Wind Tides on Lake Erie," Technical Report No.
7, Department of Geophysical Scienc9s, University of Chicago (i962).
14.
R. O. Reid and B.
R. Bodine, " Numerical Model f or Storm Surges in Galveston Bay,"
Jour. Waterways and Harbors Division, Am. Soc. Civil Engineers, Vol. 94, No. WWl, pp. 33-57 (1968).
15.
" Hydrologic Engineering M?thods for Water Resources Development," Vol. 1-12, Corps of Engineers Hydrologic Engineering Center, Davis, California (1971).
16.
" Reservoir Storage-Yield Procedures", Corps of Engineers Hydrologic E nc;ineet ing Center, Davis, California (1967).
il.
" Shore Protection Planning and Design," Technical Report No. 4, Third Ed; tion, Corps of Engineers Coastal Engineering Research Center (1966); and " Shore Protection Manual," 1973.
\\b 1
I 18.
Regulatory Guide 1.27, " Ultimate Heat Sink."
19.
" Des gn of Small Dams," Second Edition, Bereau of Reclamation, U.S. Department of i
interiot ( l '; / 3 ).
E'V*
I 2.4.11-7
20.
" Interim Peport - Meteorological Characteristics of the Probable Maximum Hurricane, Atlantic ar.d Gulf Coasts of the United States," Report "
7-97 (see also HUR 7-9/A), U.S. Weather Bureau (now NOAA) (1968).
f 21.
"Witer Surface Profiles," HEC-2, Corps of I gineers Hy1rologic Engineering Center (continuously :p:1ated).
22.
" Reservoir System Analysis," HEC-3, Corps of Engineers Hydrolcgic Engineering Center (updated).
23
" Month'.y Streamflow Simulation," HEC-4, Corps of Engineers Hydrologic Enginee-ing Center (updated).
24.
Regulatory Guide 4.4, " Reporting Procedure for Mathematical Models Selected to Predict Heated Effluent Dispersion in Natural Wa te-90 dies."
9 us m @
Rev. I 2.4.11-8