ML19317G427

Tech Spec Change Request 7 Re Tech Specs 4-1,allowing Completion of Thermal Plune Survey & Allowing Facility Operation Below 80% Min Capacity

ML19317G427
Person / Time
Site:	Crystal River
Issue date:	08/01/1977
From:	Rodgers J FLORIDA POWER CORP.
To:
Shared Package
ML19317G426	List: ML19317G425 ML19317G427
References
NUDOCS 8003030828
Download: ML19317G427 (3)

Text

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. 5 Tfchnical Specification Change Request No. 7a and b ,

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Replace page 4-1 with the attached revised page 4-1.

Reason for Proposed Change No. 7a During the peiformance of the thermal plume determination in August, when the maximum intake temperatures are observed, it is possible that the temperature of the cor. denser cooling water at the P0D will exceed 1030F for a period of more than three consecutive hours.

The purpose of the study is to determine the thermal plume at the Crystal River site under varying conditons so that the physical and mathematical models can be modified and be.available for use in evaluating any abnormal environmental occurrences or other modifications in the plant system or equipment perfonnance.

The summer thermal plume survey is scheduled for the three day period of August 15-16, 1977. Based on current-P00 temperature data, the 1030F limit may be exceeded for about five hours per day with the 1060 limit ,

never being exceeded. Because of the long intake and discharge canal system, the period of maximum temperatures is from about 8 pm till 1 am, a time when the thermal loading of the ecosystem from the sun is minimal.

The proposed change will allow the completion of this important study so that future problems or modificati.ons may be analyzed in advance to minimize any adverse thermal effects on the aquatic ecosystem.

Even though the proposed change would also be effective during the winter survey, it.is highly unlikely that the 1030 F limit would be exceeded at that time.

An-Evaluation of the Environmental Impact of the Proposed Change 7a 1

While it is recognized that extreme thermal stress may have adverse effects on the aquatic ecosystem, the near shore species in Florida are generally adapted to tolerate thermal stress because of the high thermal load from the sun (called insolation). This tolerability will allow the ecosystem to survive the possible one time stress the thermal survey may cause and will help to minimize any damage.

Because of this and the fact that the valuable information obtained in the survey may prevent damage to the ecosystem in the future, any damage to the ecosystem as a result of this change is far outweighed by the damage that may be prevented in the future at the Crystal River site.

A Benefit-Cost Analysis of the Proposed Change 7a The benefit of performing this study is that the aquatic ecosystem may be protected from adverse thermal effects in the future by having accurate thern:a1 plume models. The cost of the study in terms of adverse thermal effect on the aquatic ecosystem is uncertain. There is already 8008 03 0 [2f

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4.0 SPECIAL SVRVE1LLANCE RESEARCH, OR STUDY ACTIVITIES 4.1 THERMAL PLUME DETERMINATION DURING UNIT 3 OPERATICN Objective To establish the location and size of the thermal plume during normal operation, under conditions of high and low tide and maximum and minimum intake temperature; to provide data to verify the cathematical and physical models so that good predictions of, isotherm location under all conditions will be possible and to establish the operational monitoring system: to verify previous calculations which predict the size and location of the effluent thermal plume.

General Approach and Schedule Intensive field surveys shall be conducted twice during the first year of operation. Specifically, the surveys will be done during the months of July or August when the maximum intake temperature is observed and during the months of December or January for contrast when the minimum intake temperature is observed. The thermal field measurements shall be made in sufficient locations to cover the full extent of the thermal plume.

Salinity measurement may be required in order to effectively decouple the plume from ambient isotherms. During the tests the behavior of the plume during both phases of the tidal cycle shall be tested.

The measurements should allow for construction of the isothermal maps with 1.0 F above ambient contour intervals. These tests shall ,

be carried out with all three units operating at > 80% percent of site capacity if possible. During the surveys the folTowing conditions shall be recorded as needed to assess the extent of the thermal plume and its correspondence to a computer run with parallel parameters:

(a) plant conditions (condenser flows, intake temperature, dis-charge temperature, loading, etc.) of all three units, (,b) hydrological conditions (tidal stage, salinity traverses, etc.), (c) meteorological conditions (wet and dry bulb temperature, humidity, windspeed, wind direction, solar radiation, etc.).

The requirement of Specification 2.1.2 that the temperature of the condenser cooling water at the POD not exceed 1030F for a period _.

of more than 3 consecutive hours shall not be applicable during the performance of this study.

The field survey measurements shall be compared to the results of the predicted computer runs. Any modifications needed in either the physical model or the mathematical model will then be incorporated in the models. The models'will then be available to use in the evaluation of any abnormal environmental occurrence or other modifica-tions in plant system or equipment performance.

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much thermal loading from the sun in the ar:a of the thermal piume and since we are allowed,to operate up to 1030 F (and above it for up to three consecutive hours) at the P00, it is expected that the perfonnance of this survey will have little effect on the aquatic ecosystem of the site.

Reason for Proposed Change No. 7b The second change concerns the minimum loading of the three units at the Crystal River site during the survey. The present survey as defined-in ttie ETS requires that each unit at the site be loaded to at least 80% of capacity. Units 1 & 2 are run at 40%-50% of capacity at night because of decreased system demand and the necessity fer keeping other large power stations on line at minimum load so that the system. load requirements for the next day can be met. Wi',h Unit 3 at 100% load, the maximum load at night is s 70% for the Cryst 1 River-site. For the purposes of the survey, it'can be arranged for the Crystal River site to increase load to meet.any increased system requirements but it will not be possible to keep all units at >80% load and it may not be possible to keep the total site loading at >80% and still maintain system integrity. However, every attempt wit 1 be made to maximize the total site loading during the performance of the survey.

An Evaluation of the Environmental Impact of the Proposed Change 7b g The thermal plume determination ideally should be performed with all three units at full load for the entire survey. The proposed change would allow operation below the 80% minimum capacity required by the ETS, in order that the integrity.of the system can be maintained during periods of low demand. This reduced capacity would have less adverse effects on the aquatic ecosystem than_ running the units at >80% capacity for the length of the survey. Therefore, the change does not have an )

adverse environmental impact.  ;

A Benefit-Cost Analysis of the Proposed Change 7b The proposed change does not have an adverse environmental impact and the short time that the load will be below 80% capacity can be factored into the study so there will be no lost or inaccurate data. Therefore, the proposed change dces not have an associated cost.

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