ML20134A463
| ML20134A463 | |
| Person / Time | |
|---|---|
| Issue date: | 10/22/1985 |
| From: | Thomas C Office of Nuclear Reactor Regulation |
| To: | Klapproth J GENERAL ELECTRIC CO. |
| References | |
| IEB-79-26, NUDOCS 8511070034 | |
| Download: ML20134A463 (3) | |
Text
.
October 22, 1985 i
Hr. J. F. Klapproth Principal Licensing Engineer Nuclear Technologies and Fuel Division General Electric Company 175 Curtner Avenue San Jose, California 95125
Dear Mr. Klapproth:
SUBJECT:
ACCEPTANCE OF ADDENDUM TO LICENSIhG TCPICAL REPORT NEDE-22290, 1
SUPPLEMENT 2, "ADVAh'CED LONGER-LIFE CONTROL ROD" (ALLCR)
On July 1, 1985 the NRC found the subject topical report to be acceptable for referencing in license applications to the extent specified and under the linitations delineated in the report and the associated NRC evaluation.
By letter dated July 31, 1985, the General Electric Company (GE), requested NRC's acceptance of its position that replacement of all-B C control rod designswithcontrolledstainlesssteeltubingmaterialarhexemptfromthe requirements of IE Bulletin 79-26, with the exception of control rod life tracking. Such an exemption has been granted for the ALLCR assembly. The enclosed evaluation addendum defines the basis for our acceptance.
c We do not intend to repeat our review of the ntters described in the report and the addendum and found acceptable when the repcrt and its addendum are referenced in license applications, except to assure that the naterial presented is applicable to the specific plant involved. Our acceptance applies only to the matters described in the report and the addenden.
In accordance with precedures established in NUREG-0390, it is requested that GE publish accepted versions of this report, proprietary and non-proprietary, L
incorporating the addendum, within three months of receipt of this letter.
The accepted versions shall incorporate this letter and the enclosed evaluation between the title page and the abstract. The accepted versions shall include an -A (designatine eccepted) following the report identification symbol.
Should our criteria or regulations change such that cur conclusions as to the acceptability of. the report are invalidated, GE and/or the applicants referencing the topical report will be expected to revise and resubmit their respective documentation, or submit justification for the continued effective applicability of the topical report without revision of their respective documentation._
Sincerely, DISTRIBUTION:
i N r HBerkow
'SSPP'.Peading' RDiggs Original signed by 1
POR CThomas Cecil 0. Thomas, Chief DCS FBrecks Standardization and Special PNoonan Projects Branch HBernard Division of Licensing
' [i r
Enclosure:
As stated
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- p WASHINGTON, D. C. 20555 October 22, 1985 1
Fr. J. F. Klapproth Principal Licensing Engineer Nuclear Technologies and Fuel Division General Electric Company 175 Curtner Avenue San Jose, California 95125
Dear Mr. Klapproth:
SUBJECT:
ACCEPTANCE OF ADDENDUM TO LICENSING TOPICAL PEPORT NEDE-22290, SUPPLEMENT 2, " ADVANCED LONGEP-LIFE CONTROL ROD" (ALLCR)
On July 1, 1985 the NRC found the subject topical report to be acceptable for referencing in license applications to the extent specified and under the limitations delineated in the report and the associated NRC evaluation.
By letter dated July 31, 1985, the General Electric Company (GE), requested NRC's acceptance of its position that replacenent of all-B C control rod designs with controlled stainless steel tubing material ath exempt from the requirements of IE Bulletin 79-26, with the exception of control rea life tracking. Such an exemption has been granted for the ALLCP assembly. The enclosed evaluation addendum defines the basis for our acceptance.
We do not intend to repeat our review of the matters described in the report and the addendum and found acceptable when the report and its addendum are referenced in license applications, except to assure that the material presented l
1s applicable to the specific plant involved. Our acceptance applies only to
]
the matters described in the report and the addendum.
In accordance with procedures established in NUPEG-0390, it is requested that GE publish accepted versions of this report, proprietary and non-proprietary, 4
l incorporating the addendum, within three months of receipt of this letter.
j The accepted versions shall incorporate this letter and the enclosed evaluation between the title page and the abstract. The accepted versions shall include an -A (designating accepted) following the report identification symbol.
Should our criteria or regulations change such that our conclusions as to the acceptability of the report are invalidated, GE and/or the applicants referencing the topical report will be expected to revise and resubmit their respective documentation, or submit justification for the continued effective applicability of the topical report without revision of their respective documentation.
Sincerely, C
' A Q, f 7/, _ _ _
Cecil 0. Thomas, Chief Standardization and Special Projects Branch Division of Licensing
Enclosure:
As stated
l ENCLOSURE 3
ADDENDUM TO ALLCR TOPICAL REPORT EVALUATION l
IE Bulletin 79-26 was issued in response to instances of loss of boron from l
control rods due to tube cracking.
It required that a record be kept of the current B-10 depletion averaged over the upper quarter of the rod for every control rod, that a program be established to replace control blades having l
greater than 34 percent B-10 depletion averaged over the upper quarter of the blade (including an allowance for boron loss), that shutdown margin measure-
{
ments made at refueling outages should have an allowance for any predicted boron loss during the succeeding cycle, and that a destructive examination be performed of a highly exposed a11-B C rod.
4 i
In order to address the root cause of the boron loss phenomenon tube cracking GE performed an investigation and, as a result, has begun replacing the tubing in all-B,C r'ods with a high purity controlled stainless steel alloy 4
which is not susceptible to cracking. They conclude that the requirements of bulletin 79-26 need no longer be met for all-B,C rods with the controlled i
stainless steel tubing. We concur with that concTusion. Our concurrence is based on the following:
1.
The exposure of each control rod will still be tracked to determine when a 10 percent reduction in rod worth occurs.
j 2.
Boron loss from the control blade due to cracked tubing is not expected l
to occur. A1 extensive surveillance program is being carried out on the B,C rods in GE Hybrid I control blades. These blades are being l
irradfated as part of a lead test program in the Peach Bottom reactor to monitor the susceptibility of these rods to cracking (see NEDE-22290-A j
for details and the staff's evaluation).
Shutdown margin deteminations are required by plant Technical 3.
Specifications during startup after each refueling and will continue to be performed. However, allowance for boron loss will not be The requirement to replace rods before exceeding a 10 required.
percent reduction in relative worth will assure adequate protection.
4.
A long term surveillance program will be conducted on rods containing the new tubing. This will consist of a visual examination after the
- sixth year and for every other cycle after that. This will enhance the likelihood that incipient problems will be discovered.
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