ML20107B039
| ML20107B039 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 02/08/1985 |
| From: | Counsil W NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES |
| To: | John Miller Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20107B040 | List: |
| References | |
| A03985, A3985, TAC-52339, NUDOCS 8502200212 | |
| Download: ML20107B039 (4) | |
Text
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General Offices
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P.O. BOX 27 3
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February 8,1985 Docket No. 50-336 A03985 Director of Nuclear Reactor Regulation Attn:
Mr. James R. Miller Operating Reactors Branch #3 U. S. Nuclear Regulatory Commission Washington, D. C. 20555
References:
(1)
W. G. Counsil letter to R. A. Clark, dated September 2,1983.
(2)
- 3. R. Miller letter to W. G. Counsil, dated April 20,1984.
(3)
W. G. Counsil letter to 3. R. Miller, dated June 25,1984.
Gentlemen:
Millstone Nuclear Power Station, Unit No. 2 Proposed Revisions to Technical Specifications Steam Generator Inspections In Reference (1), Northeast Nuclear Energy Company (NNECO) proposed to amend the Technical Specifications for Millstone Unit No. 2 in regard to criteria for excluding steam generator tubes from eddy current testing.
Under that proposal, individual tubes considered inaccessible could have been excluded from the 100% inspection requirement. Inaccessible tubes, located in regions of the tube bundle where no indications of degradation had been identified, could have been omitted from the 100% inspection provided no more than 0.5% of all the tubes in the steam generator fell into that category. Reference (2) requested additional information regarding the Reference (1) proposal. This information was provided by Reference (3).
As a result of discussions with the Staff, NNECO has decided to revise its Reference (1) proposal to further reduce the total number of tubes wMch may be excluded in each steam generator and to incorporate, into tne Technical Specifications, criteria intended to increase assurance thr.t significantly degraded tubes will not be excluded.
Accordingly, pursuant to 10CFR50.90, NNECO hereby proposes to amend its operating license, Nc DPR-65 for Millstone Unit No. 2, by incorporating the changes identified in Attachment 1 into the Technical Specifications.
The proposed changes are marked by a vertical bar in the right hand margin of the P38e-
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% The proposed change adds a note to Table 4.4.6 permitting tubes which are blocked by remotely operated automated inspection equipment to be excluded from the inspection pattern in specified cases. To qualify for exclusion a tube is required to be no closer than 5 lines or 8 rows from any other tube which is found to be degraded (or which may not be inspected). The result is that an excluded tube must be in the center of an area of at least 10 lines by 16 rows (roughly
' equivalent distances due to spacing differences) or non-degraded tubes. The total number of tubes in each steam generator which may be so excluded is limited to ten (10).
Prior to the development of automated inspection equipment, inspection of steam generator tubes was the single largest source of personnel radiction exposure at pressurized water reactors. Experience at Millstone Unit No. 2 has indicated that exposures average 300 to 500 mrems for each tube end which is manually inspected.
Automated equipment has significantly reduced total exposures from steam generator inspections, but the equipment, because of the way in which it must be mounted, blocks certain tubes from being inspected.
These tubes must be inspected manually to accomplish an inspection of 100% of
' the tubes.
The requirements of 10CFR20, however, specify that personnel radiation exposures must be kept as low as reasonably achievable (ALARA).
Despite the significant savings realized by use of automated equipment, it is still
. imperative to avoid unnecessary exposure for manual inspections where exclusion of a tube from inspection can be justified (i.e., is reasonable).
The criteria specified for exclusion of individual tubes provide the necessary justification. Experience in steam generator inspections at Millstone Unit No. 2 demonstrate that tube degradation rarely affects individual, isolated tubes.
Insteads degradation affects tubes in areas. The proposed criteria, which require
. that an' excluded tube be no closer than 5 lines or 8 rows from a degraded tube,
. assure that the tube is not part of such an area. The limitation on total number of tubes excluded from inspection further reduces the chances that a degraded tube will be missed by exclusion. Additional information supporting the proposed change is contained in Attachment 2.
_The Te-hnical Specification changes proposed in Attachment I are more restrictive than the changes originally proposed by Reference (1). As reported in L;
Reference (1), the earlier change was determined to involve no unreviewed
~
safety questions, and was reviewed by the Millstone Unit No. 2 Nuclear Review
- Board. This determination and review encompassed the changes in Attachment 1.
For the same reasons, the determination made pursuant to 10CFR50.91(a),
that no significant hazards considerations are involved in the Reference (1) proposal, also encompasses the changes herein proposed. NNECO has reviewed the attached proposed license, amendment pursuant to the requirements of 10CFR50.91(a) and has determined that the changes involve no significant hazards consideration. The basis for this conclusion is that none of the criteria delineated in 10CFR50.92 have been compromised.
That is, the proposed changes do not involve a significant increase in the probability or consequences of an accident previously evaluated; create the possibility of a new or different kind of accident from any accident previously evaluated; or involve a significant
J
, reduction in. a margin of safety.
A comparison of the contents of this amendment request with the list of examples of amendments in 48FR14870 likely to involve no significant hazards ccasiderations reveals that none of the
- examples precisely envelopes this proposal.
Portions of example (vi) are applicable, in that the results of the proposed changes are clearly within all acceptance criteria. Further amplification of the basis for this conclusion is provided in Attachment 2.
It is noted that none of the examples provided as amendments likely to involve significant hazards considerations are applicable to this proposal.
Reference (1) forwarded a check in the amount of $4000 for a Class III amendment pursuant to 10CFR170. Since that time, this regulation has been amended to specify that licensees will be billed for review hours actually expended. - NNECO requests that the original payment be applied towards the required application fee and the subsequent review.
In accordance with the requirements of 10CFR50.91(b), a copy of this document is being provided to the State of Connecticut.
My Staff remains available to assist you in your review of this matter.
Very truly yours, NORTHEAST NUCLEAR ENERGY COMPANY AT141st W. G.'Counsil ' '
Senior Vice President cc:
Mr. Kevin McCarthy Director, Radiation Control Unit
' Department of Environmental Protection State Office Building Hartford, CT 06116 s
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- STATE OF CONNECTICUT )
) ss. Berlin COUNTY OF HARTFORD )
Then' personally appeared before me W. G. Counsil, who being duly sworn, did state that he is Senior Vice President of Northeast N'iclear Energy Company, Licensee herein,.that he is authorized to execute and file the foregoing information in the name and on behalf of the Licensee herein and that the statement contained in said information are true and correct to the best of his knowledge and belief.
N6tary Public [/
My Commission Expires March 31,1988 9
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