ML19269C803
| ML19269C803 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 01/24/1979 |
| From: | Counsil W NORTHEAST UTILITIES |
| To: | Reid R Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7902120208 | |
| Download: ML19269C803 (3) | |
Text
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(203) 666-6311 January 24, 1979 Docket So. 50-336 Director of Nuclear Reactor Regulation Attn:
Mr. R. Reid, Chief Operating Reactors Branch #4 U.c. Nuclear Regulatory Commission Washington, D. C.
20555
References:
(1)
W. G. Counsil letter to R. Reid dated December 18, 1978.
(2)
R. Reid letter to D. C. Switzer dated April 19, 1978.
Gentlemen:
Millstone Nuclear Power Station, Unit No. 2 Sleeved CEA Guide Tube Inspection Program As previously discussed during telephone conversations with the NRC Staf f, T 'crence (1) contained certain information which has been clacsified as ptoprietary by Combustion Engineering. The information presented below, as reworded, is non-proprietary anu may be placed in the Public Document Room.
Also, certain supplementarj information nas become available since the date of Reference (1) and has been incorporated into this letter. No additional copies of CEN-104(N)-P or the Combustion Engineering af fidavit have been pro-vided.
In Reference (2), the Commission issued Amendment No. 36 to Facility Operating License ho. DPR-65, which included authorization for Cycle 2 operation with sleeved guide tubes for certain fuel assemblies. Reference (2) also required that Northeast Nuclear Energy Company (NNECO) provide an evaluation program including planned inspections of CEA guide tubes in order to assess the per-formance of the sleeved guide tubes. Accordingly, CEN-104(N)-P, Mills tone Unit No. 2 Sleeved Guide Tube Inspection Program, is attached, which discusses the program objectives, criteria for assembly selection and examination program d e tails. The inspection program has been designed to address all aspects of sleeved guide tube operation to confirm satisfactory performance during Cycle 2 and to demonstrate the acceptability of continued use of sleeved guide tubes during Cycle 3.
The proposed inspection program will in:1ude:
(1) Eddy Current testing of certain assemblies in high wear locations (as identified by the inspections which followed Cycle 1) prior to movement of sletved fuel assemblics.
Some of these assemblies will be bundles which are scheduled to be relocated under CEA's during (f
67 0 Cycle 3 operation. The number of assemblies inspected will depend s
0 2 I 20 co3
. on initial inspection results. Eddy current techniques imilar to those employed in previous inspections will be used to e.camine guide tubes containing sleeves to assess wear condition. The degree of wear that may be expected to occur during Cycle 3 will be estimated.
(2) Visual examination of sleeved assemblics that were visually examined during the last refueling autage to confirm guide tube integrity af ter one operating cycle.
(3) Pull tests of sleeves in a discharged assembly to verify mechanical integrity of the sleeve-guide tube joint.
(4) Examinations of a selected number of the CEA's themselves to verify test results which have indicated negligible wear.
The specific bundics which are candidates fo. 'xamination are provided in Attach-ment 1.
Bundles scheduled for discharge will be given lower priority for examina-tion.
Criteria are being developed in more detail to determine the degree of uear (as indicated by eddy current testing) which is acceptable for, a) fuel movement, b) reinsertion in the core in a wear location, i.e.,
under a CEA, and c) rein-sertion in the core in a location which is not under a CEA.
NNECO will inform the Staf f of those acceptance criteria in subsequent correspondence.
The above points and the attached evaluation program describe a well-balanced program which will adequately serve to confirm the acceptability of CEA guide tube sleeves. NNECO has intentionally structured this program to pro-vide the flexibility required to minimize critical path time and to accommodate other refueling outage priorities, while still adequately evaluating the performance of sleeved guide tubes. On the basis of CE's test program, NNECO and CE expect very little wear of the sleeve and certainly do not ex-pect any wear of the guide tube itself.
This consideration is dominant in the determination of the number of bundles under consideration for inspection.
Should our anticipations be realized during initial examination ef forts, inspection of greater numbers of sleeved assemblies would be clearly unwarranted. Therefore, it is the intention of NNECO to fulfill the program objectives as cutlined in the attachment and allow the examinatien program to evolve as the results of the initially inspected assemblies become available.
The Cycle 3 core will be structured as follows:
a) Employ 12 presently sleeved assemblies under CEA's (87's and 4C's) b) Sleeve 57 additional assemblies for use in CEA locations (5B's,12C's, 2SD's, and 12E's) c) Employ 4 assemblies of the reduced guide tube flow design under CEA's (4E's).
These are scheduled for use under CEA Croup 7.
d) Sleeve ti e remaining 68 3atch E assemblies.
~ NNECO has reviewed this submittal pursuant to the requirements of 10CFR170 and has determined that no fee is required. The basis for this determination is that this program is a continuation of an issue which developed prior to the ef fective date of 10CFR170.
Due to the proprietary nature of the material contained in CEN-104(N)-P, NNECO requests that CEN-104(N)-P be withheld fro.a public disclosure in accordance with the provisions or 10CFR2.790 and that this raatcrial be safeguarded. The reasons for the classification of this material as proprietary are delineated in the enclosed affadavit provided by Combustion Engineering. Copies of the non-proprietary version of this document are also provided.
It is our understanding that the attached program fulfills the Staff's request documented in Reference (2).
Very truly yours,
NORTl! EAST NUCLEAR ENERGY COMPANY
/.L j W. G. Counsil Vice Prcsident At tachment