ML20072Q231
| ML20072Q231 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 03/31/1983 |
| From: | Howe P CAROLINA POWER & LIGHT CO. |
| To: | Vassallo D Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20072Q234 | List: |
| References | |
| LAP-83-69, NUDOCS 8304040503 | |
| Download: ML20072Q231 (5) | |
Text
Cp&L Carolina Power & Light Company MAR 311983 Serial:
LAP-83-69 Director of Nuclear Reactor Regulation Attention:
Mr. D. B. Vassallo, Chief Operating Reactors Branch No. 2 Division of Licensing United States Nuclear Regulatory Commission Washington, DC 20555 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NOS. 1 AND 2 DOCKET NOS. 50-325 AND 50-324 LICENSE NOS. DPR-71 AND DPR-62 SPENT FUEL POOL EXPANSION RESPONSE TO REQUEST FOR INFORMATION
Dear Mr. Vassallo:
In a letter dated February 23, 1983, (Serial No. LAP-83-28),
Carolina Power & Light Company (CP&L) committed to provide a response to five questions from your staff received on January 17 and 18, 1983. Enclosure 1 provides copies of those questions and our responses.
In order to provide an expedious response to question 5, CP&L has elected to modify the Technical Specification (TS) revision submittal to prohibit storage of fuel not meeting the present approved fuel reactivity conditions as measured in terms of U-235.
Appropriate replacement TS pages are attached.
90 8304040503$$b024 PDR ADOCK o ppR P
411 Fayetteville Street
- P. O. Box 1551
- Raleigh, N. C. 27602
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D. B. Vassallo Carolina Power & Light Company believes that this letter provides responses to all outstanding questions from your staff on this subject.
Once again CP&L would like to reiterate the very critical schedule that CP&L is facing with regard to the spent fuel pool modifications and respectfully requests that the TS revision request be approved as expeditiously as possible.
Yours very truly, 0.U P. W. Howe Vice President Brunswick Nuclear Project JSD/ mag (6419JSD)
Enclosures P. W. Howe, having been first duly sworn, did depose and say that the.
information contained herein is true and correct to his own personal knowledge or based upon information and belief.
k Y-Y/1Y Notary (Seal).
My commission expires: 6f/ffU
'j>
,e cc:
Mr. D. O. Myers (NRC-BSEP)
Mr. J. P. O'Reilly (NRC-RII)
Mr. S. D. MacKay (NRC) l i
D. B. Vassallo to LAP-83-69 RESPONSE TO NRC QUESTIONS Question 1:
Provide sufficient information to demonstrate that the free-standing racks mounted on the free-standing pedestals are conservatively stable for all postulated loading conditions. To that end, the analysis for sliding and tiping should account for rack / fuel dynamic effects, dynamic rather than static vertical accelerations, the potential for rotation of the racks about the vertical axis, and the fact that the racks are mounted on free-standing pedestals.
Response
The information requested is available in the " Brunswick Steam Electric Plant Unit Nos. I and 2 Spent Fhel Storage Expansion Report", (latest revision transmitted to the Nuclear Regulatory Commission by Carolina Power & Light Company April 16, 1981),
hereafter referred to as the Expansion Report, and the "Righ Density Spent Fbel Storage Mbdules for Brunswick Units 1 and 2 Summary Engineering Calculation Report", NEDO-24948, (transmitted to the Nuclear Regulatory Commission by Carolina Power & Light Company March 16, 1982), hereaf ter referred to as the Calculation Report.
The analyses for sliding and tiping presented in Section 4.1, Seismic Analysis, of the Expansion Report the Section 2, Seismic Analysis, of the Calculation Report sufficiently demonstrate that the free-standing racks mounted on the free-standing pedestals are conservatively stable for all postulated loading conditions.
In Section 2.3, Natural Frequencies and Seismic loads, of the Calculation Report, the modules can be treated as essentially " rigid" in the vertical axis because the first mode vertical frequency always exceeds 30 Hz.
For this reason, a constant vertical OBE/DBE acceleration was used.
In Section 2.4.3, Analysis Results, of the Calculation Report, the actual rotation of the modules during a seismic event and the safety factor against seismic overturning are addressed.
Safety factors against overturning range from 2,712 to 15,700.
l Question 2:
Provide sufficient information to demonstrate that leveling of the racks will not be a problem.
Response
The installation procedure for the High Density Fuel Storage (HDFS) Modules requires elevation testing of the support bases prior to HDFS module installation.
The corners of an installed module are required to be within 1/16 inch of each other in elevation.
The method of leveling the module on the support bases will be by shimming the slider pad feet of the module.
After following the elevation procedure contained in the detailed instructions section of the modification procedure, the number of shims and their thickness for each slider pad foot will be determined by the installation engineer.
Proper installation of the slider pad feet at the required locations will be verified by Quality Control Inspectors.
The elevation l
testing and slider pad foot installation procedures are in l
1 l
l
D. B. Vassallo sufficient detail to provide the necessary data and shimming required to achieve and verify proper leveling of the HDFS modules.
Question 3:
Provide an analysis for upward loads on the rack (downward on the handling gear) to assure that a stuck fuel assembly will not cause unacceptable consequences.
Response
An analysis for upward loads (forces) on the rack is not necessary to assure that a stuck fuel assembly will not cause unacceptable consequences.
Loads calculated for seismic conditions in Section 4.1, Seismic Analysis, of the Expansion Report (see response to Question 1) and for impact by a falling fuel bundle in Section 4.3, Fuel Bundle / Module Impact Evaluation, of the Expansion Report exceed any loads conceivable f rom the stuck fuel criteria of 2,000 pounds upward force and 1,000 pounds horizontal force (see Section 4.2, Stress Analysis, Item F of applied loads of the Expansion Report).
Added conservatism is provided by the use of load cell interlocks that limit the lifting force of the fuel handling hoist to 1,000 pounds.
Question 4:
Provide sufficient information to demonstrate for the new loads the adequacy of the existing pre-stressed concrete girders which support the fuel pool.
Response
A design load of 2,000 pounds per square foot over the entire pool fuel floor in addition to the weight of the water was used to cize the existing pre-stressed concrete girders. The design load far exceeds the loading of the fuel pool floor as a result of the fuel and new rack system.
Therefore, the limiting component of the fuel pool floor was analyzed and the pre-stressed concrete girders which support this fuel pool were not.
Question 5:
Your analysis of the criticality of the spent fuel storage pool considered the storage of BWR fuel bundles having a maximum multiplication factor (Koo) of 1.35 in the new high density storage locations.
If it is intended that this type of fuel may be stored in the old low density storege locations, then show that for the most reactive configuration, the multiplication factor (Keff) for the entire fuel storage pool would be less than 0.95.
If this type of fuel will not be permitted in low density storage locations, show that adequate precautions will be taken to prevent inadvertent storage of this fuel in the low density storage locations.
Response
The analysis of the criticality of the spent fuel storage pool uses a generic General Electric analysis for the high density fuel storage (HDFS) modules. This analysis uses a highly enriched BWR fuel bundle having a maximum multiplication factor of 1.35.
The existing non poisoned spent fuel storage racks 1
D. B. Vassallo were previously analyzed and licensed to store BWR fuel containing not more than 15.6 grams of U-235 per axial centimeter of active fuel assembly, and a maximum assembly average loading of 3.0 w/o U-235.
We are presently limiting ourselves to purchasing and' storing new fuel which will not exceed existing technical specifications for fuel storage.
Even though higher enriched fuel could be stored in the HDFS modules, the present technical specification limits will be used for both the HDFS modules and the present BWR grid mounted racks. This will prevent inadvertent storage of higher enriched fuel (i.e, maximum multiplication factor of 1.35) in the low density storage locations.
In the event that the use of fuel which exceeds the current technical specifications becomes desirable in the future, we will reassess both the existing non-poisoned racks and the HDFS modules prior to storing such fuel at Brunswick. It should be noted that more than ten percent excess margin is provided in the criticality analysis for the existing non poisoned racks.
(6419JSD mag)