ML17223A530
| ML17223A530 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 02/19/1990 |
| From: | Sager D FLORIDA POWER & LIGHT CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| L-90-59, NUDOCS 9003020227 | |
| Download: ML17223A530 (9) | |
Text
ACCELERATED D UTION DEMON TION SYSTEM J
REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)
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ACCESSION NBR:9003020227 DOC.DATE: 90/02/19 NOTARIZED: NO FACIL:50-335 St. Lucie Plant, Unit 1, Florida Power
& Light Co.
AUTH.NAME AUTHOR AFFILIATION SAGER,D.A.
Florida Power 6 Light Co.
RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)
SUBJECT:
Forwards summary of testing 6 test results from study conducted on 891004-06,per integrity assessment program.
DISTRIBUTION CODE:
A001D COPIES RECEIVED:LTR ENCL SIZE:
TITLE: OR Submittal:
General Distribution NOTES:
DOCKET 05000335 D
RECIPIENT ID CODE/NAME PD2-2 LA NORRIS,J XNTERNAL: ACRS NRR/DOEA/OTSB11 NRR/DST/SELB 8D
. NRR/DST/SRXB 8E
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NOTE TO ALL"RIDS" RECIPIENTS:
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P.O. Box14000, Juno Beach, FL 33408-0420 FEBRUARY 1 9 1990 L-90-59 U. S. Nuclear Regulatory Commission Attn:
Document Control Desk Washington, D.
C.
20555 Gentlemen:
Re:
St. Lucie Unit 1 Docket No. 50-335 Spent Fuel Pool Boraflex Panels Inte rit Assessment.
Pro ram By letter L-89-246, dated July 10,
- 1989, Florida Power
& Light Company (FPL) outlined to the NRC its plans to conduct a study program to neutron log or "blackness test" Boraflex panels in Region 1 spent fuel pool cells at St.
Lucie Unit 1.
By letter dated August 3,
1989 (J.
A. Norris to C.
O.
Woody),
the NRC concluded that FPL's proposed study program for blackness testing in Region 1 of the St. Lucie Unit 1 spent fuel pool was acceptable.
The study program described in FPL letter L-89-246 was conducted October 4-6, 1989.
On the basis of the tests conducted in accordance with the study program, FPL has concluded that the St.
Lucie Unit 1 Region 1 spent fuel cells are performing properly.
A summary of the testing and test results is attached.
This concludes FPL's activities with respect to performance demonstrations and integrity assessment testing of the St.
Lucie Unit 1 spent fuel pool. If you require further information on this topic, please contact us.
Very truly yours, D. A.
ger Vice r sident St. Lucie Plant DAS/EJW/gp Attachment CC:
Stewart D. Ebneter, Regional Administrator, Region II, USNRC Senior Resident Inspector, USNRC, St. Lucie Plant 9003020227 900219 PDR ADOCK 05000335 PDC P
an FPL Group company
ATTACHMENT
SUMMARY
OF BLACKNESS TESTING OF BORAFLEX IN SELECTED CELLS OF THE SPENT FUEL POOL STORAGE RACKS OF ST ~ LUCIE UNIT 1 Introduction Neutron logging (blackness) tests were conducted in selected cells of the St. Lucie Unit 1 spent fuel storage racks for the purpose of confirming the integrity of the Boraflex neutron absorber material.
These tests were conducted October 4-6, 1989, using a
specially designed logging tool containing a
Californium-252 neutron source and four boron trifluoride (BF,)
thermal neutron detectors.
Calibration traverses were also made in a special test
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cell constructed with known Boraflex gaps ranging from approximately 0.25 inch to 4 inches in width.
These calibration tests demonstrated that gaps of 0.5 inch in width may be readily detected in the blackness tests.
Calibration Testin A test cell was constructed with known gaps in the Boraflex at specified locations.
Figure 1 presents the size and locations of the gaps in the calibration test cell.
Based upon the average of several traverses, a calibration curve was developed (Figure 2),
relating the peak deflection in the trace at the location of the gap to the size of the known gap. With this calibration curve, the percent deflection observed during the test runs was correlated to a width of gap in the spent fuel pool cell Boraflex panel.
Summar of Test Results A total of 20 spent fuel cells were tested, of which 15 were designated as test cells intentionally exposed to the radiation from spent fuel removed from the reactor core in the July 1988 refueling.
These cells have been exposed to the radiation from one cycle of spent fuel (from July 1988 to October 1989) and the maximum estimated radiation dose to the Boraflex was 1.2 x 10" RADs.
Five cells were also tested in an unirradiated area of the Region 1 storage racks to provide a reference.
The blackness tests encompassed 60 full length Boraflex panels in the irradiated test cells and 16 Boraflex panels in the unirradiated area of the storage rack.
The largest indication noted corresponded to a gap of about 0.4 inches in width.
A few 0.25 inch deflections were observed in the un-irradiated cells.
The deflections which were correlated to gaps on the order of 0.25 inch are at the limit of gap detectability.
These indications, therefore, may or may not be indicative of gapping in the Boraflex.
Conclusion Criticality safety analyses have demonstrated that 0.5 inch gaps are acceptable.
On the basis of the measurements, it is concluded that the Boraflex has performed properly, with no gaps equal to or greater than 0.5 inch in the cells tested.
These cells are considered representative of the St.
Lucie Unit 1 storage racks'ells.
140 9/32" 1/2" 1~r TQR 3/4" 3 1/32"
) /gN 30 1 5/1C" 1/r 1/2" s/r 10 0.075" TNCK 901QAD DCKPT AS HOKQ OH SOE 2 fig. 1 GAP DISTRIBUTION IN THE CAUBBATION CELL
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PERCENT OF FULL SCALE DEFLECTION
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