ML19221A968
| ML19221A968 | |
| Person / Time | |
|---|---|
| Issue date: | 03/31/1979 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| References | |
| NUREG-75-087, NUREG-75-087-02.4.12, NUREG-75-87, NUREG-75-87-2.4.12, SRP-02.04.12, SRP-2.04.12, NUDOCS 7907120081 | |
| Download: ML19221A968 (4) | |
Text
NUREG 75/081
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STANDARD REV EW PLAN
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h OFFICE OF NUCLSAR REACTOF; REGULATION SECTION 2.4.12 DISPERSION, DILUTION, AND TRAVEL TIME 5 Of ACCIDENT AL RilEASES OF LIQUID Ef f LUENTS IN SURF ACE WATERS RE'!IEW RF 5 POW BILI TIE S l
Primiry - Hydrology-Meteorology Branch (flMB)
Secondary - Effluent Treatment Systems Branch (EISB)
I.
ARE AS OF REVlW The ability of the surface water environment to disperse, dilute, or concti.trate accidental l radioactive liquid effluent releases is reviewed with emphasis on relating the effects of such releases to existing and known future uses of surf ace water resources. (Note that effects of normal releases and of the more likely accidents are discussr* in the applicant's environmental report.)
II.
ACCtPTANCF CRITERIA Transport characteristics of the surf ace water environment with respect to existing and known f uture users must be described f or conditions which reflect worst case release mechanis'is and source tertns so as to postulate the most pessimistic contamination f rom accidentally released liquid ef flus,ts.
Estimates of physical parameters necessary to calculate the transport of liquid effluent from the points of release to the site of exist ng or k nown future users must be described. Potential pathways of contamination to surface wate users must be identified. Sourt?s of information and data must he described aM r ef ertnced.
Acceptance is based on the staff's evaluation of the applicant's computational u thods and the apparent completeness of the set of parameters necessary to perform the analysis.
One-or two-dimensional mathematical models are acceptable to analyze the fluw field and convective dispersion of contaminants in surface waters, providing that the models have been verified by field data and that conservative site-spec. ic hydrologic parameters are used.
Furtharmore, conservatism must be the guide in seletting the proper model to represent a specific physical situation. Radioacti e decay and sediment adsorption may be considered, if applicable, providing that the adsorption factors are conservative and site specifir.
III. REVIEW PROCFDURE S Section 2.4.i2 of the applicant's SAR is reviewed to identify any missing data, information
- o. analysis necessary for the staff's evaluat,oi..
Applicant responses to the requested USNRC STAND ARD REVIEW Pt AN
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.aformation will be evaluated using the methods outlined below and staff positions will
. developed. Resolution, if possible, of differences between staff's and the applicanU<
'mation of liquid effluent dispersion will be coordinated through the LPM; and the vill be written accordingly.
Independent <alculations will be made of liquid effluent transport for the contamination
- athways identified. For preliminary analysis, the staff will employ simplified ca'cula-tional procedares or models, such as those cun wi" n References 2 and 8.
The a.21ysis ta t e performed us'ng demonstrably conservative coef ficients and assumptions, arid the w ital conditions (such as lowest recorded river flow) likely to give the most adverse di:cersion of the liquid effluent. The applicant's model assumption and resu;ts will be
.ompared with the staff's results to assure that the results are comparably conservative.
,he estimation of liquid effluent dispersion will reflect potential future changes that might result from variations in use by known future surface and groundwater users.
Concentrations of radionuclides in the body of water under consideration will be calculated t,ased or. the staff's dispersion computations and with initial concentrations provided by the Effluent Treatment Systems Branch (LISB) for the most critical event. Accept aility
>f the resultant concentrations of radioactive effluent at the points of interest will us determined by consultation with ETLB.
If the concentrations of the diluted liquid effluents ccmputed by the staff are within acceptable limits of Appendix B, Table II, Column 2, of 10 CFR Part 20, no further computation effort is indicated. If the concentra-tions computed by conservative simplified methods exceed the limits of Part 20, more precise and less conservative models, such as those used for hydrothermal prediction (r ference 9), and coefficients wiil be emoloyed by the staff.
e IV.
EVALUATION FINDINGS For construction permit (CP) reviews, the findings will summarize the applicant's and l
staff's estimates of dilution factors, dispersion coefficients, flow velocities, travel times, and potential contamination pathways between the site and the nearest water user.
I If the estimates are comparable, or if no potential problem exists, staff concurrence with the applicant's estimates will be stated. If the staf f predicts substant ially more conservative conditions, a statement of the staff basis will be made.
For operating license (OL) reviews of plant designs that have had detailed reviews of severe accidental effluent releases at the CP stage, the CP conclusions will be rcierenced.
If no CP review of effluent releases was undertaken of the scnce indicated herein, this will be indicated. Any new potential pithways or changes in water usage that can be identified in the OL review will also be analyzed and reported.
Simple statements for CP reviews follows:
"At the staff's request, the applicant provided analyses of the effects (travel times, diversion c" fficients, dilution factors, etc.) of an accidental spill of liquid radioactive wastes into the surface water.
A postulated failure of the
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condensate storage tank. releasing 500,00L gallons of water contai-ing low-level activity was evaluated The applicant assumed that this voluma ai water would travel overland to the adjacent stream before any dilution would occur. The applicant concluded, and the staff concurs, that adequate dilution would occur in the surface water prior to reaching any potential users.
The applicant also investigated the the spill being recircu ated through the plant circulatinq water possibility of l
system. This analysis showed t hat it was extremely unlikely that recirculation could occur since the condensate storage tank is located dowastres n of the circulating water it.take structure. The staf f cone.urs in this evaluation. Accidental spills that could enter the ground water and reach potential users before or after dischary-ing into surface waters are discussed ir. Sections 2.4.13 and Section 15 of this report.
"No accidental release of sufficient volume of liquids containing radioactivity directly int.o surface waters is considered reasonable at the site because storage facilities are located inside of safety-related buildings and the manner in which liquids. ire to be handled at the site precludes this possibility. Accidental spills of liquids into the groundwater, which c ould eventually reach surf ace waters, are discussed in Sections 2.4.13 and 15 of this report."
V.
REFERENCES In addition to the following references describinq methods and techniques of evaluation, published data by federal, state, and other agencies and erginizations will be used as available.
1.
N.
H.
Brooks, "Diffision nf Sewage Effluent in an Ocean Current," in " Waste Disposal in the Marine Environmont," Pergamon Press, Nes York (1960).
2.
H. B.
Fisher, "The Mechanics of Dispersion in Natural Streams," Jour. Sanitary Engineering Division, Proc. Am. m. Civil Engineers, Vol. 93 No. HY6, pp. 187-216
( 1 %8).
H.
B. fither, " Dispersion Predictions in Natural Streams, Jour. Sanitary Engineering Division, Proc. Am. Soc. Civil Engineers, Vol. 94, No. SAS, pp. 92/-943 (1968).
4.
E. Gaspar and M. Oncescu, Radioactive Tracors in Hydiology," Elsevier Publishing Co., Ne., Yo r k ( l'; 72).
5.
S. N. Davis and R. J.
M. DaWiest, "Hydrogeology," Joan Wiley & Sons, Inc., New Y rk (1966).
6.
Regulatory Guide 1.70, " Star dard Format and Content of Safety Analysi eports for Nuclear Power Plants."
2.4.12-3 Rev-I
7.
"NRC Dispersion Workbook," (in prep 3 ration).
8.
Regulatory Guide 1.113, " Estimating Aquatic Dispersion of Effluents from Accidental and Routine Reactor Releases for the Purpose af Implementing Appendix I,"
9.
G. H. Jirka, G. Abraham, D. R. F. Harleman, "An Assessaent of Techniques for Hydrothermal t'rediction," USNRC, NUREG 0044, 1976.
10.
Regulatory Guide 4.4, " Reporting Procedure for Mathematical Models Selected to Predict Heated Effluent Dispersion in Natural Bodies of Water."
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