ML17207A874
| ML17207A874 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 03/07/1980 |
| From: | Robert E. Uhrig FLORIDA POWER & LIGHT CO. |
| To: | Reid R Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML17207A875 | List: |
| References | |
| L-80-77, NUDOCS 8003110524 | |
| Download: ML17207A874 (5) | |
Text
REGULATORY INTQRATION DISTRIBUTION SYSTE@RIDS)
ACCESSION NBR ~ 8003110524 DOC, DATE: 80/03/07 NOTARIZED:
NO FACIL:50 335 St, Lucie Pl anti Unit ii Florida Power 8 Light Co, AUTH,NAME AUTHOR AFFIL'IATION UHRIGI R ~ E ~
Florida Power 8 Light Co ~
RECIPE NAME RECIPIENT AFFILIATION REIDiR ~ 6 ~
Operating Reactor s Branch
SUBJECT:
Forwards rept "RCS Asymmetric LOCA Load Evaluationi" in response to NRC 780216 requests Probability of pipe failure is acceptably low.Facility has significant capability to accommodate nondesign basis events'OCKET 05000335 DISTRIBUTION CODE:
A030S COPIES RECEIVED:LTR ENCL SIZE:
Z+R TITLE: Asymmetric Loca Loads NOTES:
RECIPIENT ID CODE/NAME ACTION:
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FLORIDA POWER 8L LIGHTCOMPANY March 7, 1980 L-80-77 Office of Nuclear Reactor Regulation Attention:
Mr.
R.
W. Reid, Chief Operating Reactors Branch 84 Division of Operating Reactors U.
S. Nuclear Regulatory Commission Washington, D.
CD 20555
Dear Mr. Reid:
Re:
St. Lucie Unit 1
Docket No. 50-335 As mmetric LOCA Loads The NRC Staff's February 16, 1978 letter requested that we expand the asymmetric LOCA load analysis beyond the scope committed to in our letter of February 9, 1976, which addressed the capability of reactor vessel supports only.
Our August 1977 report, entitled "Reactor Support System - Evaluation of Margins",
was fully responsi ve to our February 1976 commitment.
By letter dated March 23, 1978, we indicated a willingness to consider further studies once FP&L received Staff concurrence as to the acceptability of the analytical methods used in our August 1977 report.
On January 16, 1980, the Staff and its consultant met with us to discuss the asymmetric load evaluation for St. Lucie Unit l.
At that time, we agreed to provide additional data on our efforts to assess the effects of asymmetric LOCA loads.
Our willingness to pursue the complex studies requested by the Staff should not be construed to mean that we concur with the need for such studies.
To the contrary, we believe that sufficient data exists to support the contention that these large reactor coolant system pipes cannot fail in the instantaneous manner postulated by the Staff.
The studies have been conducted because we recognize the Staff's need to assess the potential impact that could be associated with these exceedingly low probability events.
The attached report discusses additional analyses conducted to assess the significance of structural
- gaps, the capability of other reactor coolant system component supports, and the effects of connected ECCS piping.
The conclusion reached is that, for the guillotine breaks
- analyzed, the existing design can acceptably accommodate these arbitrarily postulated events.
These analyses also reconfi rm the conclusions reached in our August 1977 report.
Studies are also underway to assess the capability of the fuel/internals and control element drive mechanisms.
The results of these studies are anticipated in July 1980.
It must be noted, however, that the small displacements observed for the reactor pressure vessel and core barrel strongly suggest that these studies. will also yield acceptable results.
S 0 0 8 > > 0 gg 'f PEOPLE... SERVING PEOPLE
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Office of Nuclear Reactor Regulation Page Two The conclusions to be derived from our efforts to date are that the probability of the types of pipe fai lures required to be assumed for these analyses is acceptably low, and that the St. Lucie Unit 1 design has a significant inherent capability to accommodate these non-design basis events.
Very truly yours, Robert E. Uhrig Vice President Advanced Systems 8 Technology REU/FGF/PKG/cph Attachment cc:
Mr. J.
P.
O'Rei lly, Region II Harold Reis, Esquire