ML18078A416
| ML18078A416 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 11/20/1978 |
| From: | Librizzi F Public Service Enterprise Group |
| To: | Schwencer A Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7811240219 | |
| Download: ML18078A416 (3) | |
Text
e OPS~G Public Service Electric and Gas Company 80 Park Place Newark, N.J. 07101 Phone 201 /430-7000 November 20, l978 Director of Nuclear Reactor Regulation
- u. s. Nuclear Regulatory Commission Washington, D. C.
20555 Attention:
Gentlemen:
Mr. A. Schwencer, Chief Operating Reactors Branch 1 Division of Operating Reactors INCREASED CAPACITY SPENT FUEL RACKS NO. 1 UNIT SALEM NUCLEAR GENERATING STATION DOCKET NO. 50-272 Public Service Electric and Gas Company hereby submits additional information in support of its application to increase the spent fuel storage capacity at the Salem Nuclear Generating Station.
This information is in response to discussions held with members of your staff.
This submittal consists of forty copies.
Should you have any questions regarding this application, please do not hesitate to contact us.
Attachment The Energy People Very truly yours, L.v(.
. b '":'y)'A F. P. Li r-t.EZl General Manager -
Electric Production 11001 J s -If 1/'ID 95* 2001 ( 400M) 9-77
I. --.
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ADDITIONAL INFORMATION IN SUPPORT OF QUESTIONS 17 AND 23 A summary.of the non-linear and linear elastic cases which have been analysed and the results obtained therefrom are as follows:
Case Initial Condition
--:--:-Friction Coefficient Wall Im12act l
Equally spaced 0.3 No impact 2
Equally spaced 0.2 No impact 3
One rack against wall 0.3 21,800 lbs.
Linear Elastic
.. o. 3 7,000 lbs.
wall load The above analyses all considered racks full of fuel which cause the maximum wall loads.
It should be noted that, for Case #3, the friction coefficient used in the analysis was erroneously reported as 0.2 in our submittal of July 31, 1978.
The friction coefficient te~t data previously submitted were the
- actual results obtained for indiviaual tests.
The recent report:
"Friction Coefficients of Water-Lubricated Stainless Steels for
- a. Spent Fuel Rack Facility 11 by Professor Ernest Rabinowicz of.*
MIT, performed for the Boston Edison Company provides considerable additional data.
This report provides the results of *134 tests-.:.-
Load net that are representative of the Salem fuel storage.rack/pool environ-ment.
The results of test series 1, 3, 5 and 7 from the report were neglected.
These tests were performed at a sliding speed of 4 inches/sec., compared to 0.04 in/sec for the other sliding tests.
Since the average friction coefficient is substantially higher
-than the maximum value of 0.4 requir~d to permit sliding it is anticipated that the racks will not slide.
The 134 low speed sliding and static test results were, therefore, considered as being representative.
A statistical analysis of the 134 test results shows a mean friction coefficient of 0.563 and a standard deviation of 0.096.
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The lowest single value measured for these 134 tests was 0.37.
The statistical analysis of these-small diameter ( 0. 09") friction tests to determine a minimum friction value is very conservative in that each rack module is supported on seven feet, each of which is 6 inches diameter.
This tends to average the friction coefficient and to suppress extreme values.
The results of these
~
tests are in good agreement with the results previously reported and demonstrate the conservatism of using a value of 0.3 for analytical purposes.
The test results also show that there is a high probability that, even under SSE seismic conditions, the racks will not slide on.the pool floor and the wall braces will be unloaded There is no technical justification for assuming that racks are in contact with a pool wall when analyzing a seismic event.
The racks are initially installed in the center of the pool with a thermal expansion clearance between the wall braces and the pool
- walls on all four sides. Initial pool heat-up will cause all rack modules to move outward from the center of the pool, after which each module will be free to expand and contract about its own center.
As a worst case, the condition can be postulated wherein a rack at one end of _the pool remains stationary and the other three racks expand away from that rack towards the other end of the pool.
The resulting minimum gap of O.llS" is sufficient to ensure that even one rack would not subsequently be impacted by the wall during a seismic event.
The assumed presence of one rack against a wall does not result from analysis, but was arbitrarily considered solely for the purpose of establishing a conservative design basis for the strength of the wall braces.
Clearly, con-sideration of lumping more than one rack against a wall is not warranted.
The second paragraph in the answer to the second question presented a qualitative discussion of multiple rack impacts, not based on analys~s~ Considering the foregoing discussion that paragraph~
should be disregarded.
. -. -*~-