ML20039D615

Comments on Facility Site Restoration Plan,In Response to NRC 811120 Ltr.Monitoring Wells Outside Excavation Necessary for Future Monitoring Should Not Be Capped

ML20039D615
Person / Time
Site:	Bailly
Issue date:	12/23/1981
From:	Garrett F INTERIOR, DEPT. OF
To:	Harold Denton Office of Nuclear Reactor Regulation
References
NUDOCS 8201050271
Download: ML20039D615 (2)

Text

- - - - - - - - - - - - - - - - - - - - -

u>

, c,

. .~ '

j

+

~~

t t

United States Department of the Interior B-RECEfVED ]

<' NATIONAL PARK SERVICE JAN5 585 g-WASHINGTON, D.C. 20240 (g k38W Tx m marty maram ro: @

DEC 2 31981  :

Mr. Harold R. Denton Director, Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Ccmnission Washington, D.C. 20555

Dear Mr. Denten:

In response to your letter of Novmber 20, 1981, in which you requested our cmments on the proposed Bailly Nuclear One site restoration plan, we offer the following ccanents:

1. Sealing and capping of wells: We are unclear about the extent of proposed sealing / capping of wells, sump casings, transducers, etc.,

before backfilling in the excavation and in areas separated frm the excavation. We recm mend that all Unit 3 wells in the excavation be filled with concrete before backfilling. Because of the hydrologic connection between Units One and Three at the excavation site, wells which are not cemented are potential avenues for flcw between the lower sand and upper sand aquifers. While this would probably not appreciably alter the flow system in either aquifer unit, it could allow any future contamination that might occur in the lower sand aquifer to migrate more easily into the upper sand near the excavation site. In such a case, the west end of the Cowles Bog Wetland Ccmplex could be inpacted if water of undesirable quality would move through the slurry wall or the sheet pilings on the northeast part of the excavation.

Monitoring wells outside the excavation which are necessary to future nonitoring should not be capped.

2. H-Piles: We see no problans arising frcm the leaving-in-place of the H-Piles after cutting them off at +8 feet. Their total rmoval might destroy the integrity of the hydrologic regime of the area.

3. Slagged Lay-Down and Railroad Spur Areas: There is inadequate information for us to be able to cmment on the proposal for the slagged lay-down area and railroad spur area. This area, from the plan description, appears to be adjacent to Lakeshore property. We would neal more information, including a map, to evaluate this part of the proposed plan.

f l f.Ql pnpaBih A

N -

- ' o

4. Backfill ?tterial: Groundwater flow near the excavation could also be affected LDin nature of the backfill material. If this material differs appreciably in hydrologic conductivity frcm the original material, the water table altitude may differ, which could slightly alter the shallow groundwater regime. The mineralogical and chmical cmposition of the backfill material could affect groundwater quality near the Ocules Bog Hetland Cmplex if the material is significantly different frm the original material. Even if the water is potable, the chmistry of dissolved constituents may differ enough to have an impact on plants in the uctlands. Thus, quartz sand such as originally was present, is the most desirable fill material. Tne following backfill materials appear suitable:

a. Material rmoval frcm the excavatizm or other clean, inorganic fill materials of a character not appreciably different in hydrologic conductivity or quality frcm the original material.

b. Sand, presently located on the Bailly site winch is silicious in cmposition and arenaceous in size, or sand of the type generally found in the area surrounding the Bailly site.

We are assured that the Nuclear Regulatory Camission will retain its regulatory responsibility through cmpletion of the Bailly h\x: lear One site restoration. We are pleased with NPC's and NIPSCO's intention to restore the property and we appreciate this opportunity to make cmments on the plan.

Sincerely, CW C' N

$7CiG Dr9n-Director