ML19343A826

Forwards Assessment of Influence of Dewatering at Bailly N-1, in Response to Secretary of Interior 801003 Ltr to Chairman Ahearne Re Possible Impacts of Const Dewatering

ML19343A826
Person / Time
Site:	Bailly
Issue date:	11/20/1980
From:	Shorb E NORTHERN INDIANA PUBLIC SERVICE CO.
To:	Harold Denton Office of Nuclear Reactor Regulation
Shared Package
ML19343A827	List: ML19343A826 ML19343A830
References
NUDOCS 8011210566
Download: ML19343A826 (2)

Text

.

,;.0 Noctaheen Indiana Public Service Company

@messo General Off.tes l 5265 Hohman kwe t l Hammond kdana 4632E l Tel.: 853-5200 (219 EUGENC M. SHORS renst vice angslOgNT November 20, 1980

_, E O

~

i n m ,

9  %

i Mr. Harold Denton, Director . i Nuclear Reactor' Regulation fi _ Gd Nuclear Regulatory Commission -[ Li 55 Washington -D. C. 20555 h o

e "5-g O -- z

Dear Mr. Denton:

We wrote to you on October 21, 1980, concerning the October 3,1980 letter from Cecil D. Andrus, Secretary of the Interior, to Chairman Ahearne. -We pointed out that the Secretary's conclusions regarding possible impacts of construction dewatering at Bailly N-1 on the Cowles Bog area of the Indiana Dunes National Lakeshore, in our opinion, can-not be validly drawn from the USGS reports referenced in the October 3 letter. We also indicated that we would submit a detailed response to the Secretary's letter. Twenty-five copies of that report are attached. Its major conclusions can be summarized as follows: -

1. Using actual field data _(including the results of pumping tests and demonstrated permeabilities), the calculated lateral extent of drawdown produced by NIPSCO's planned dewatering system (the " radius of influence") is less than 950 feet. Even when the erroneous coefficient of permeabilities assumed by the~ USGS is us2d in the calculations, the radius of influence does not exceed 1450 feet. It is therefore clear that dewatering associated with construction of Bailly N-1 cannot have any effect on Cowles Bog, which is more than 8000 feet away.

2. The drawdown predicted by the USGS is wrong and unreliable for several- reasons. The USGS modelignored or misused a substantial body of field data available for the study area.

The assumptions used by USGS bear little resemblance to the j field data. Finally,; there are defects in application of the l model itself.

1 1

1 8 0'1 3 2 1 06N [ l

,a h e p m .o-,

Mr. - Harold Denton, Director Hammond, Indiana Nuclear Reactor Regulation Novembe r 20, 1980-i Page Two The effects of dewaterlag were carefully and ' accurately addressed during the Bailly construction permit hearint on environmental matters. A sub-stantial quantity of additional field data has been accumulated since the-hearing, which demonstrates that the predictions of dewatering effects made at the hearing were conservative; i. e. , the predicted effects are greater than the actual effects. _ The additional data provided in the attached report clearly demonstrate that Bailly N-1 dewatering cannot affect Cowles Bog, . obv d ting any reason to update or supplement the Environmental Impact Statement in order to re-examine dewatering effects. We urge the NRC Staff to complete promptly preparation of the environmental impact appraisal which Staff counsel has indicated will be ready by January 15, 1981.

Very truly yours, f / /

'G -

EMS: cgs Attachment .

i l

I l

- - . ,