ML20057A658

Submits Info in Support of Conclusion That No Temporary Support Necessary,W/Regard to Stone Arch Culvert Located Near Hoosac Tunnel,Per Util 930802 Submittal of Calculations Re Adequacy of Local Roads to Support SG Haul Loads

ML20057A658
Person / Time
Site:	07109256
Issue date:	09/10/1993
From:	Mellor R YANKEE ATOMIC ELECTRIC CO.
To:	Chappell C NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS)
References
BYR-93-067, BYR-93-67, NUDOCS 9309150111
Download: ML20057A658 (3)

Text

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YANKEE ATOMIC ELECTRIC COMPANY

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September 10,1993 BYR 93-067 1

l U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 Attention:

Mr. Cass R. Chappell, Section Leader Cask Certification Section Storage and Transport Systems Branch Division of Industrial and Medical Nuclear Safety Office of Nuclear Materials Safety and Safeguards

References:

(a)

Docket No. 71-9256 (b)

Letter, R. Mellor, Yankee Atomic Electric Company, to C. Chappell, U.S. Nuclear Regulatog Commission, dated August 2,1993

Subject:

CERTIFICATE OF COMPLIANCE In Reference (b), Yankee Atomic Electric Company (YAEC) provided the Nuclear Regulatory Commission (NRC) with a set of calculations which demonstrated the adequacy of the local roads to support the Yankee Nuclear Power Station steam i

generator haul loads. Mention was made of the evaluation of a stone arch culvert which is located near the Hoosac Tunnel. The evaluation concluded that, although this culvert met the performance criteria,it should be bridged or braced from the inside during the steam generator hauls. This assessment was based on limited information about the l

culvert, obtained during our initial walkdown in July 1993. We have reevaluated this structure and have concluded that no temporary support is necessary. The following information is being provided in support of that conclusion.

The arch culvert is approximately 6 feet wide and 9.5 feet high as it passes under River Road. There are about 11.5 feet of cover (soil and placed rock) above the high point of the arch. This structure was reexamined by two YAEC structural engineers on August 26,1993. The stonework under the road appears to be in good condition. With the j

exception of several small stones at the end of the culvert (some 20 feet off the edge of.

the road), all of the stonework is intact. The arch itself is about 18 inches deep, with 140033 l

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, U. S~ Nuclear Regulatory Commission Page 2 September 10,1993 additional stonework placed above the arch. It is not possible to determine the actual thickness of this stonework since it is covered with soil.

Cascade Brook flows through the culvert as it approaches its terminus at the Deerfield River. This brook carries amoff from Whitcomb Ilill, through which the 5 mile long i

i lloosac Tunnel is cut. The brook enters an open channel, approximately 100 feet long, near the tunnel entrance. The side wall of the channel, which runs parallel to the railroad tracks, is a stone retaining wall about 8 feet high. This wall is only 16 feet from the centerline of the tracks. The channel terminates at the entrance of the arch culvert which runs several hundred feet along the railroad tracks. This section of the cuhert is lecated directly beneath a gravel staging area which is often used for railroad i

maintenance. The retaining wall and the arch culvert have supported lateral loads from l

locomotives and freight trains since the tunnel was constructed in 1877. The culvert has not only been exposed to lateral loads but also to vertical loads from heavy railroad maintenance vehicles. Both the channel wall and the arch culvert appear to be in good condition.

It is logical to assume that the culvert stonework under River Road does not differ significantly from the construction near the track. This culvert apparently was built at the same time the tunnel was cut, so there was an ample supply of stone. Railroad structures such as these built in the last century have performed very well. Most of them are in service today.

A failure of the arch culvert resulting from the steam generator haul load is not credible.

In the unlikely event any damage were to occur to this structure it would be a sloughing c

of the road surface, not a catastrophic failure which could jeopardize the transporter and cargo. Temporary support systems will not significantly increase the safety of the haul i

operation. Bridging the culvert at road level with steel plates will not substantially reduce the load on the arch due to the substantial depth of the arch below the road surface. Constructing a temporary bracing system inside the culvert would be difficult and potentially dangerous due to the dark, wet conditions. Such an internal system could be an impediment to flow and would not significantly increase the safety of the haul operation.

Considering the above, it is best to leave the arch culvert as it is during the steam generator hauls. An inspection of the culvert will be performed before and after each steam generator haul. Any change in the condition of the structure will be noted and

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. U. S.' Nuclear Regulatory Commission Page 3 September 10,1993 evaluated to determine whether remedial action should be taken. If you should have any questions regarding this or any other road calculations, please contact Ms. Jane Grant at (508) 779-6711.

i Sincerely, i

s YANKEE ATOMIC ELECTRIC COMPANY

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Russell A. Mellor Project Manager f

Yankee Rowe Project 4

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N. Osgood, NRC, NMSS M. Fairtile, NRC, NRR E. Kelly, NRC Region I H. Lambert, Manager Berkshire County Survey Department I

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