ML19261C593
| ML19261C593 | |
| Person / Time | |
|---|---|
| Site: | Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png |
| Issue date: | 03/15/1979 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19261C585 | List: |
| References | |
| NUDOCS 7903230314 | |
| Download: ML19261C593 (8) | |
Text
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%,.....f ENVIRONMENTAL IMPACT APPRAISAL BY THE OFFICE OF NUCLEAR REA SUPPORTING AMENDMENT NO. 32 TO DPR-61 CONNECTICUT YANKEE ATOMIC POWER COMPANY HADDAM NECK PLANT DOCKET NO. 50-213 Description of Proposed Action _
By letter dated June 4,1976 the Connecticut Yankee Atomic Power Company (the licensee) submitted proposed changes to the Appendix B Environmental This appraisal Technical Specifications for the Haddam Neck Plant.
addresses changes to Specifications 2.1.2 Rate of Change of Discharge Temperature, 2.3.1 Biocides, 2.3.2 L, 2.3.3 Dissolved Oxygen, 3.1.1 Fish H
Impingement, 4.1 Fish Deterrent Studies, and 4.3 Phytoplankton Studies.
Environmental Impacts of Proposed Action Specification 2.1.2 limits the rate of change of discharge temperature A.
The licensee proposed to modify the specification by adding to 8 F hour.
a phrase that the specification would only apply to conditions resulting The licensee contends that tidal changes can have from plant operations.
short term effects on the rate of change measurements ani the plant operations should not be modified for this reason.
Although the plant has been producing comercial power since early 1968, the FES statement was not finished until October 1973 and the environ-During the mental technical specifications (ETS) issued in December 1974.
first year of plant operation with the ETS, the licensee found that the water temperatures at the plant intake showed significant increases over With a 2 to 5 hour5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> period closely correlated with the time of high tide.
a constant AT across the condensers this causes similar increases in the As this increase is beyond the control of the discharge temperatures.
plant and is due to an "apparently natural phenomenon," the licensee requested relief from this specification by adding the phrase "as a result of plant operation."
The staff reviewed the licensee's submittal but questioned whether the increase in water temperature at the intake was not due to recirculation The licensee's response of May 6,1977, of heated discharge water.
790323 03td
- indicated that under certain circumstances the rising flood tide carries heated water from the discharge canal upstream to the intake structure, causing a rise in intake temperature and, therefore, discharge temperature.
These circumstances occur when the river is low or restricted by ice and the approach of the heated water is rapid enough that both the intake and The licensee discharge temperatures rise more than 8 F in an hour.
indicates that this has occurred about 6 times per winter.
The staff has reviewed the environmental impact of operation of the plant without power restrictions during the time that the intake In our temperature rises due to recirculation of discharge water.
judgement, there should be no significant impact from this cha plant operation.ture change would occur infrequently (<10 times / year) and be duration (only occurring on high flood tides).
assumed that similar rises of the same magnitude occurred before the ETS were issued and no apparent effects were noted in the Connecticut RiverIn ad l being conducted at that time.
to the licensee, no effects have been observed during the recent winter Ecological Study when weather conditior. were severe and the hourly tempera-Ther (1976-1977) ture rise exceeded 8 F on six occa siom.
is acceptabic.
Specification 2.3.1 limits the average increase in total residual Chlorination chlorine concentration in the discharge to 0.1 mg/1.This level had been B.
times are also not to exceed 120 minutes a day.
The found adequate to control fouling of the condenser cooling system.
review in the Haddam Neck (Connecticut Yankee) N of 0.1 mg/l are not, in general, injurious to aquatic life.
The licensee proposed to increase the concentration of chlorine in the discharge water from 0.1 mg/l of total residual chlorine to 0.5 mg/lThe maximum of free available chlorine.
this change was that it was the level contained in the recently issued National Pollutant Discharge Elimination Systems (NPDES) perm by the State of Connecticut.from the licensee to establish the need for the More importantly, the staff terms of controlling condenser fouling.
requested a detailed evaluation of the impacts this higher concentratio would have on aquatic biota in the discharge canal and site vicinity.
The staff's particular concern was the effect on fish residing in and overwintering in the intake canal where they would b the proposed level have been indicated as being toxic to many fish species 2).
k
~ On May 6,1977, the licensee responded to our request for additional chlorine discharge by indicating that such an impact as come from the USEPA or the State of Connecticut which granted the higher The State and EPA usually do not perform an impact limits in its NPDES.
analysis in setting guidelines or limits and in this case the staff has determined that no written appraisal is available from the State or EPA.
Apparently the reason for the State applying the highe being reevaluated).
Without an impact assessment from the licensee or the permitting agency, the staff finds that it does not have sufficient information to fulfill the NRC's responsibility under NEPA to appraise the impacts that may occur at the higher limits.
proposed change to the chlorine limit of specification 2.3.1 is not justified and is not acceptable at this time.
The licensee proposes to change specification 2.3.2.1 to add the phrase "or within 1.0 pH units of intake, except during perio C.
We find this change acceptable because pH chanaes in the intake water are on occasion conditions outside the pH range of 6.8 to 8.5 by Specification 2.3.2.1, exist naturally in the river.
Specification 2.3.3 limits the difference between the dissolved oxygen concentration in the discharge canal and that at the intake D.
structure to 2.0 mg/ liter as a result of plant operation.
The licensee proposed to change the specification to limit the dissolved oxygen concentration in the discharge canal to be not less than 5 milli-grams per liter except during those periods when the intake waterThe cha concentration is below this level.
cation consistent with the dissolved oxygan requirement in the NPDES permit issued by the S' ate of Connecticut for the Haddam Neck Plant.
Our review of the Haddam Neck Plant FES, the bases contained in the ETS and the operating data for the years 1975 and 1976, indicates that The bases for spec.ification this specification is no longer necessary.
2.3.3 state that the purpose for the dissolved oxygen limit is to minimize the effect plant operation could have on aquatic life in the discharge Data for the years 1975 and 1976 canal and in the Connecticut River.
show that the dissolved oxygen concentration in the discharge canal is changed as a function of the saturation of the intake water and the
. Normally, oxygen in saturated or temperature of the discharge water.
supersaturated water at intake temperature decrease h
Occasionally, when unsaturated water is present at the intake it becomes saturated by the plant by the aerating action discharge temperature.
of the pumps and by flowing over the discharge weir.
The slight changes in dissolved oxygen as water passes through the p Water passing through are not creating a significant impact to biota.
Times of low dissolved the plant remains saturated in dissolved oxygen.
oxygen in the river only occur infrequently in the sumer months and are primarily related to phytoplankton blooms in the river and l
oxygen would not affect canal biota, as fish are not nomally in the can related to plant operation.
Sessile forms are similarly reduced because of the high temperatures.during the summer months because o concentrations.
In the winter, when temperatures are below about 4 Such conditions were passing through the plant condensers.
documented during a study of DO in the discharge canal when the D0D0 heated by saturation level ranged from 110% to 119%.I been found to be detrimental to salmonid fishes by causing gas bubble However, creel surveys of sport fishemen fishing in the discharge canal have not revealed fish with visible sy disease.2 winter are able to tolerate this level of supersaturate disease.
Studies have shown that certain non-salmonid fresh-wate It is also saturated.
species are more tolerant to supersaturated conditions conditions.
We conclude that this specification can be deleted in the canal will be insignificant.
Specification 3.1.1 requires that the number of fish impinged on h
plant intake screens be estimated by sampling the intake screen tras E.
Impinged fish are to be identified, counted and The number impinged per month is estimated by extrapolating th baskets once each week.
In addition, Table 3.1-1 of the ETS measured.
weekly counts to a monthly total.
When contains monthly report levels for each species by si ds In establishing their report levels, then a report must be sent to the NRC.
d the present monthly report levels, the licensee reviewed the observe t
maximum monthly totals for each species-size category from daily coun taken from 1968 to 1972.
. The licensee proposes to change certain of the species-size report levels and the words in the bases referring to the report levels from "If the maximum total observed was less than twenty-five, the report level was set at twenty-five" to "If the maximum total observed in twenty-five days is less than twenty-five, the monthly report was set at thirty-one." The licensee's justification is that the monthly accordingly increased. totals did not always include the full cenplement because of missing daily observations. observed monthly totals adju were taken.
In considering the licensee's change we have reviewed the basis for requiring the report levels on fish impingement nun The FES indicated that the early years of operation resulted in substantial losses of fish on the screens and concluded tha ETS.
The licensee had agreed at that of fish inninaement should continue.
time to conduct studies on fish deterrent devices to reduce impingement sampling was to be conducted to determine the efficacy However, the FES did not require report levels.
The Bases section of this specification indicates that the report levels the various devices.
were established "to assure continued protection of fish population.
Our review of the data from the 1975 and 1976 annual envi monitoring reports indicates that yearly fish impingement numbers at the plant have been reduced considerably since the early operational 1968 - 1911 is about The average yearly total for the period fish (unadjusted for days not samoled) while the average forThis maj years.
300,000 the years 1975 and 1976 is about 11,000 fish.
impingement is primarily due to the testing and use of the electrical fish deterrent system installed in 1971 which has been especiallyIt is also pos effective on small (< 3 in.) young-of-the-year fish.
that the size of the fish populations in the Connecticut River hasSo decreased since plant startup.is that declines in the juvenile and adult ca 1 although no far-field fish population from the period 1965 - 1972 2
monitoring (except for migratory shad) have been conducted since 197.
However, reductions in fish populations have occurred gradually over a number of years while the use of the fish deterrent system r k
quite effective in reducing impingement and that operation of the inta impingement suddenly.
structure will have little effect on fish populations.
, Review of the seven reports on exceeding the levels in Table 3.1-1 during the last three years indicates that the increased impingements were typically due to fluctuating abur. dances of migratory species in the sit vicinity or to shifts in the size-class structure of the population and not due to a change in plant operation.
The staff concludes that monthly report levels on the impinged and the causes of the increased impingement repor are no longer necessary.
The impingement monitoring program will be continued, particularly in regards to testing of the final deterrent device.
the levels.
Yearly reviews of the numbers of the various species and sizes imping will be performed to assure continued protection of fish populations in Therefore, the monthly report requirements are However, the fish impingement will continue to the site vicinity.
deleted by this change.
be reported in the Annual Environmental Operating Report.
Specification 4.1, Fish Deterrent Studies, requires a special study to determine the efficacy of utilizing an electric device at the intake F.
as a means of reducing the numbers of fish impinged on the screens.
This study was to be performed during 1974 as part of the continuing fish Upon completion of these studies, the design and operational mode which will be most successful in reducing the fishS impingement study program.
impinged at the plant is to be recommended.
and operational modes of electrical barriers have been submitted by the licensee in its Annual Operating Reo intake.
A description and drawing of the new system were provided to NRC by letter 1976.
The staff's review of the sunnary report, impinge-ment monitoring data and the final installed system indicates that the of November 28, 1977.
use of the electrical deterrent device will be effective in reducingFur impingement on the intake screens.
device will be carried out through the impingement monitoring program.
The staff concludes that the licensee has satisfied the objective of specification 4.1 and this requirement can be deleted from the ETS.
Specification 4.3 required the licensee to conduct a one year study to determine the influence of plant operation on phytopla G.
in the Connecticut River.
- However, which included one year of plant operation.
the FES required the one year follow-up study because at the time the from 1965 - 1969 FES was written overall increases in phytoplanktan populations and a decline of diatom species in favor of blue-green algae had been noted in the plant region of the Connecticut River.
The licensee collected phytoplankton samples from three stations in the The results from this study were river from April through November 1975.
compared to the previous study which had noted the overall increase inAltho populations and change in species composition.
were highly variable, the numbers reported in 1975 were considerablya 1968 - 1969 reduced from the yearsThe unusually high numbers of phytoplankton observed in 1968 and 1969 were probably related to increased nutrient levels from sourcesThis study year 1967.
upstream as previously stated by the licensee.that it is highly unlike acted as an additional stimulant.
The ETS study also did not find consistent or significant species shifts that would be considered unusual for a riverine community.
The staff concludes that the licensee has addressed the concern FES on phytoplankton and has satisfied the specific Conclusion and Basis for Negative Declaration On the basis of the foregoing analysis, it is concluded that there will be no environmental impact attributable to the propose Having made this conclusion, FES for the Haddam Neck Nuclear Power Plant.
the Cannission has further concluded that no environmental impact statemen for the proposed action need be prepared and that a negative declaration to this effect is appropriate.
Dated: March 15,1979
- REFERENCES CITED 1.
Herriman, D. & L. Thorpe, editors, The Connecticut River Ecological study - The Impact of a Nuclear Power Plant, Amer. Fish. Soc. Mono-graph No.1,1976.
2.
Mattice, J. S. & H. E. Zittel.
Site-Specific Evaluation of Power Plant Chlorination. Jour.
Water Pollution Control Federation 48(10):2284 - 2308.
1976.
3.
Fickeisen, D. H. and M. J. Schneider, editors.
Gas Bubble Disease.
Proceedings of a Workshop held at Richland, Washington, 1976.
.