ML19263D770

LER 79-021/04L-0 During 1978:difference of More than Two Std Deviations Existed Between Preoperational Study & Operational Study in Metabolic Functions of Discharge Salt Marshes Adjacent to Facility.Cause Natural or Seasonal

ML19263D770
Person / Time
Site:	Crystal River
Issue date:	04/03/1979
From:	Richard Bright FLORIDA POWER CORP.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML19263D766	List: ML19263D765 ML19263D770
References
LER-79-021-04L, LER-79-21-4L, NUDOCS 7904130242
Download: ML19263D770 (3)

Text

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SUPPLEMENTARY INFORMATI0tl

1. Report No.: 50-30%/79-021/04L-0

2. Facility: C : ~ al River Unit No. 3

3. Report Date: /; , 3, 1979

4. Occurrence Date: Winter, Spring, Summer and Fall quarters of 1978 (discovered 15 March 1979)

(determined at plant 2 April 1979)

5. Identi fication of Occurrence:

A difference of more than two standard deviations (>20) existed be-tween the preoperational study and the operational study in the meta-bolic functions of the folicwing aquatic systems adjacent to Crystal River Unit flo. 3:

a) Discharge Salt Marshes (Scartina) for dead biomass during the Sumner quarter, b) Discharge Salt Marshes (Juncus) for live biomass during the Winter, Spring, Sumner and Fall quarters; for dead bicmass during the Summer and Fall quarters; and for gross productivity during the Sumner quarter.

6. Conditions Prior to Occurrenca:

The site generator capacity factors for the first (Winter), second (Spring), third (Summer), and fourth (Fall) quarters of 1978 were 62.5"., 35.8"., 32.5%, and 57.9"., respectively. Crystal River Unit No. 3 was shutdcun from March 3 through September 29.

7. Descripticn of Occurrence:

In Table 1 is the description of the preoperational mean, the preoper-ational two sta.1dard deviation (20), the operational mean, and the determination whether the operational mean was greater than (>) or less than (<) the preoperational mean ! two standard deviations for each of the items of Section 5 above.

8. Designaticn of Apparent Cause:

The appare'nt causes of the greater than two standard deviation change of the metabolic functions in the Salt Marshes could be natural or seasonal variations or these variations in conjunction with the in-creased thermal output from the site due to Crystal River Unit No. 3.

9. Analysis of Occurrence:

In the Salt Marshes, the possible natural cr seasonal variations in conjunction with the possible effect of the Crystal River Unit No. 3 addition to the site thermal discharge may have caused the change in the metabolic functions observed in the operational study as ccmpared RonSright(LER )D62 7904130242_

9. Analysis of Occurrence: (Continued) to the preoperational study. However, these changes may be temporary as the ecosystem reorganizes itself to the new conditions. The sug-gestion of cause and ef fect by Crystal River Unit No. 3 can only be cor.-oborated by the continuance of this study since greater than two standard deviation difference did not exist between preoperational and the operational data in the remaining quarters.

A period of adjustment of the ecosystem was expected concurrent with Crystal River Unit No. 3's initial operation. Therefore, changes in the operation of the unit are not required, and the present program to monitor the environment will be continued.

10. Correcti'e Action:

The change in metabolic functions in the Discharge Salt Marshes can-not, at this time, be attributed to either natural phencmenon or a specific man-made cause. Therefore, the present study will be contin-ued to verify, if possible, the cause. Until such time, n corrective action can be defined.

11. Failure Data:

This is the third report for this type occurrence. Refer to:

78-022/04L-0, dated 31 July 1978.

78-024/04L-0, dated 19 September 1978.

RonBright(LER)

D52

Table 1 Preoperational Operational Operational Mean

> or < Preoperational A_qua_ tic Syst93 Metabolic Function Quarter Mean 2_0 Mean Mean 2a Discharge Salt DeadBjomass Suniner 447.1 149.0 704 >

Marshes (Spartina) (g/m )

Discitarge Salt Live Biomass Winter 47S 210 850 >

Marshes (Juncus) (g/m2 )

Spring 500.0 218.8 1043 >

Summer 531.3 312.5 1139 >

Fall Si)0. 0 312.5 1280 >

Sununer 955 430 1792 >

DeadBjomass (9/m )

Fall 860 260 1427 >

GrossPrgductivity Suniner 6.0 2.0 3.85 <

0 (9 2/m -d)

RonBright(LER) 062