ML19275A724
| ML19275A724 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 09/26/1979 |
| From: | Reid R Office of Nuclear Reactor Regulation |
| To: | Lundvall A BALTIMORE GAS & ELECTRIC CO. |
| References | |
| NUDOCS 7910190028 | |
| Download: ML19275A724 (6) | |
Text
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NUCLEAR REGULATORY COMMISSION E
WASHINGTON, D. C. 20555 o
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September 26, 1979 V
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Cocket No. 50-318 Mr. A. E. Lundvall, Jr.
Vice President - Supply Baltimore Gas & Electric Company P. O. Box 1475 Baltimore, Maryland 21203
Dear Mr. Lundvall:
In the review of your CEA guide tube evaluation program for Calvert Cliffs, Unit No. 2, dated September 7,1979, we find that additional information, as delineated in the enclosure, is necessary to complete our review.
Contrary to a statement in your September 7,1979 letter, we do not, at
. this time, consider sleeving as a satisfactory long-term solution to the guide tube wear problem.
In addition, our safety evaluation for the Cycle 2 reload, dated October 21, 1978, approves operation with modified (sleeved and reduced flow) guide tubes for Cycle 2, only. Therefore, we must review the corrective actions you take in regards to the CEA guide tube wear pro-blem and issue a safety evaluation on this subject before Cycle 3 operation comences.
You are requested to provide the additional information identified in the enclosure in a timely manner.
Sincerely, l/.
Robert W. Reid,. Chief Operating Reactors Branch #4 Division of Ocerating Reactors
Enclosure:
Request for Additional Information cc: w/ enclosure See next page 1179 032 0 17 7910190
i Baltimore Gas & Electric Company cc:
Janes A. Biddiso'1, Jr, Mr. R. M. Douglass, P.anager General Counsel Qua.lity Assurance Department G and E Building Room 923 Gas & Electric Building Charles Center P. O. Box 1475 Baltimore, Maryland 21203 Baltimore, Maryland 21203 George F. Trowbridge, Esquire Shaw, Pittnan, Potts and Trowbridge 1800 M Street, N.W.
Washington, D. C.
20036 f1r. R. C. L. Olson Baltimore Gas and Electric Company Room 922 - G and E Building Post Of fice Box 1475 Baitimo e, Maryland 21203 fir. Leon B. Russell, Chief Engineer Calvert Cliffs Huclear Power Plant Baltinore Gas and Electric Company Lusoy, itaryl and 2C557
~ Bechtel 'ower Corporation ATTH: nr. J. C. Judd Chief Nuclear Engineer 15740 Shady Grove Road Gaithersbt.rg, Maryland 20760 Combustion Engineering, Inc.
ATTH:
Mr. P. W. Kruse, Managra Engineering Set sices Post Office Box 500 Windsor, Connecticut 06095 Calvert County Library Prince Frederick, Maryland 20678 4
e 1179 033
REQUEST FOR ADDITIONAL INF0PMATION CEA GUIDE TUBE INSPECTION PROGRAM CALVERT CLIFFS UNIT NO. 2 DOCKET NO. 50-318 Provide the following information related to your submittal dated September 7,1979.
A.
ALL CATEGORIES OF FUEL ASSEMBLIES 1.
Provide Cyc.le 2 and Cycle 3 core maps identifying Category la, lb and 2 core pos itions.
Identify in tabular format the assembly category, expos tre, wear time, CEA type, high crimp ECT signal, average crimp ECT signal, pull tests results, recrimp, general coments, and any other pertinent charreteristics which are considered important for evaluation purposes.
2.
Describe and discuss.the ECT and pull test that will be preformed in-core and out-of-core.
3.
Describe the fuel handling criteria for each of the fuel categories.
Compare and discuss any observed differences in measured 30C-2 versus EOC-2 J.
ECT results.
~
S.
CATEGORY la~ FUEE ASSEMBLIES 1.
A minimum of five (5) sleeved Batch D assemblies should be selected to confirm crimp adequacy.
We also suggest a minimum of three (3) pull tests on those sleeves which exhibit the lowest ECT indications at the crimp.
If any of these sleeves fail the pull test, the number of pull test should be increased.
2.
Provide your correlation of crimp adequacy versus pull test results for the new crimp design and compare these results with the old style crimp design resul ts.
3
iscuss the recrimo or reexoansion crit.9ria nrnnosed for the catecory la assemblies or the sleeves which have been pull tested.
C.
CATEGORY Ib FUEL ASSEMBLIES 1.
This category of fuel assemblies resulted in inadequate crimps at CCNPP-1.
Verify that the crimping procedure used at CCNPP-2 included the pull test prior to the expansion step.
1179 034
. 2.
State how many of these assemblies will be discharged, and how many will go into non-CEA locations.
3.
Propose a minimum number of visual examinations to inspect for guide tube cracks in the region of the crimp.
4.
Specify a minimum number of pull test to be performed and provide th'e basis for selection. The basis may include, but not limited to, the following considerations: ~
~
a.
Low ECT crimp signal, b.
Non-CEA location in Cycle 3 with low ECT crimp signal, c.
Observed fractures in guide tube crimp region, d.
Axial position change, e.
Discoloration in sleeve or guide tube and/or f.
Cycle 1 wear considerations.
5.
Do you propose pull-to-destruction test of category lb sleeves? If not, provide your justification for eliminaticn of these te:ts.
6.
What criteria determines the need for recrimping?
7.
What is your acceptance criteria for a recrimped sleeve?
8.
What visual examinations will be performed after the recrimp procedures?
9.
Specify if pull tests will be performed on any of the recticpsd sleeves.
- 10. Will reexpansion be performed follcwing the recrimp?
11.
If reexpansion is performed,. vill it be before, or after, a pull test?
1179 035
- D.
CATEGORY 2 FUEL ASSEMBLIES In our telephone conversation on September 24, 1979, your staff indicated that no new category 2 fuel assemblies were' planned for Cycle 3.
It was also indicated that BG&E,. based on the latest CE test results, was not optimistic about the guide tube wear characteristics of the category 2 assemblies. The rasults of the CE tests should be provided to support continued or discontinued use of the category 2 fuel assemblies.
1.
What criteria has been established for continued, or discontinued, use of the category 2 assemblies in CEA locaticns, and/or non-CEA locations?
2.
What criteria determines how many guide tubes will be azicuthally eddy-cur"_nt tested for local wear?
3.
What is the minimum number uf guide tubes that will be azimuthally eddy-current tested?
4.
Your Cycle 2 reload submittal stated that if excessive wear was observed in the category 2 fuel assemblies they would be sleeved for Cycle 3 use.
a.
What criteria determines excessive wear requiring sleeving and is this criteria different fcr CEA and non-CEA locations?
b.
What criteria determi<.es excessive waar requiring discontinued use?
5 If sleeving is installed in the category 2 assemblies and they are placed under CEA's in Cycle 3, or future cycles:
a.
How will sleeving effect scram time?
- b., How will sleeving effect CEA cooling?
c.
How will sleeving effect local boiling in annulus between the sleeve and the guide tube?
E.
CEA EXAMINATICNS Your workscope does not commit to a definite number of CEA examinations, nor does it commit to specific tests.
Provide your comparisons with similar tests at CCNPP-1 and other facilities and reference the specific document (s,) and section(s) of the referenced document (s) from which the similar data was obtained.
If this information has not been previously orovided to NRC, it must be provided.
1179 036
s
-4 l.
Specify. the minimum number (preferably 5) of CEA's that will be eddy-current tested.
2.
Describe the ECT method, equipment, and the CEA areas tested.
3.
Provide information on the ECT calibration correlations.
4.
Provide the ECT acceptance criteria.
5.
Specify the minimu.n nunber (preferably 5) of CEA's that will be
. visually examined to characterize the surface appearance of the CEA rods.
6.
Describe your method (s) of visual examination, the areas examined, and the reliability of these examinations to detect: fatigue cracking, stress corrosion cracking, abrasion, denting, and other surface characteristics which c3uld impede CEA movement, degrade their function, or reduce their design life.
7.
Because CEA's are subject to multiple cycles, and continued vibration, what supporting test data and criteria provides assurance that unacceptable accumulative damaga will not occur within the design life of the CEAs.
4 1179 037