ML20042E465
| ML20042E465 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 04/16/1990 |
| From: | Walt T PORTLAND GENERAL ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20042E466 | List: |
| References | |
| NUDOCS 9004230141 | |
| Download: ML20042E465 (7) | |
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.I April 16, 1990 Trojan Nuclear plant Docket 50-344
_i License NPF-1 l
U.S. Nuclear Regulatory Commission ATTN:
Document Control Desk Washington DC 20555 i
Dear Sirs:
i License change Application 187. Revision l' l
Attached is one signed original of Revision 1 to License Change. Application (LCA) 187 requesting amendment of Operating License NpF-1.
This LCA l
modifies the Technical Specification requirements for steam generators to allow tube repair by sleeving as an alternative to plugging. ' Portland Ceneral Electric Company submits this revision to incorporate changow which were discussed with the Nuclear Regulatory Commission staff on April 10, l
1990.
Revision bars inve been added to Attachment A to indicate where changes have been made from Revision 0 of this LCA.
Furthermore, to expedite your approval of this request, Combustion Engineerirs, l
Incorporated, has been deleted as.one of the ver. dors for which we tro i
socking approval as a supplier of sleeving services. To avoid unnocessary duplication, the vendor sleeving topical reports and accompanyir.g affidavits, previously transmitted by our letters-dated November 30, 1989 an(.1anuary 25, 1990, are not included with this revision to the LCA.
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121 S W S$nto Street. Portand. Oregon 97204 ~
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Document Control Desk April 16, 1990 Par.e 2 Also attached is one signed copy of a Certificate of Service for LCA 187, Revision 1 to the chief executive of the county in which the facility is located and the Director of the State of Oregon, Department of Energy.
Sincerely, T. D. Walt Acting Vice President, Nuclear Attachments
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Mr. John B. Martin Regional Administrator, Region V U.S. Nuclear Regulatory Commission Mr. David Stewart-Smith State of Oregon Department of Energy
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Mr. R. C. Barr NRC Resident Inspector Trojan Nuclear Plant i
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l PORTLAND CENERAL ELECT 3IC COMPANY EUGENE WATER & ELECTRIC BOARD AND l
PACIFIC POWER & LIGHT COMPANY I
t Operating License NPF-1
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Docket 50-344 License Change Application 187, Revision 1 l
This License.7hange Application requests modifications to Operating-License NPF-1 for the Trojan Nuclear Plant to revise the Trojan Technical i
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Specifications for steam generators to allow tube repair by sleeving as an alternative to plugging.
PORTLAND CENERAL ELECTRIC COMPANY O
By T. D. Walt Acting Vice President,
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Nuclear Subscribed and sworn to before me this 16th day of April 1990.
Ndtary Publ6 G Oregon My Commission Expires:
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l bCA 187, Rev. 1 Attachment A page 1 of 4 Description of Changes The proposed changes to Trojan Technical Specification (TTS) 3/4.4.5,
" Steam Generators", and the associated Bases will allow sleeving of steam generator tubes. There are also three editorial changes as indicated below in Item 7.
The specific changes are as follows:
1.
TTS 4.4.5.2.b.1 is changed so that whereas it was required to include all nonplugged degraded tubes in the first sample of tubes selected'for each inservice inspection, nov only the nonplugged degraded tubes that have not been sleeved in the affected area will be required to be included in the sample.
2.
TTS 4.4.5.4.a.11 is changed to clarify that F* distance no longer applies if a sleeve is insts11ed in the roll expanded portion of a tube.
3.
TTS 3/4.4.5 throughout is changed to require the same actions for sleeves with imperfections as is required for tubes with imperfec-tions.
4.
TTS 4.4.5.4.a.5 is changed to refer to the repair limit rather than the plugging limit in the definition of " defect".
5.
TTS 4.4.5.4.a.5 is changed so that whereas a tube containlag a defect was defined as defective, now a tube containing a defect and j
not sleeved in the affected area is defined as defective.
6.
TTS 4.4.5.4.a.6 is changed so that what was called the " plugging limit" is now called the " repair limit". The definition indicates that when a tube reaches the limit, the tube shall be removed from service by plugging or can now be repaired by sleeving in the affected area.
Also, when a sleeve in a tube reaches the limit, the tube shall be removed from service by plugging. A related footnote has been added to indicate which vendor-supplied sleeving services have been approved by the Nuclear Regulatory Commission (NRC) for use at Trojan.
7.
TTS 4.4.5.1. TTS 4.4.5.2, and Table 4.4-2 are changed to incorporate l
editorial corrections including, respectively, removal of an extra period, corrected spelling of the word " inspection", and removal of a stray mark.
8.
TTS 4.4.5.4.b is changed so that whereas a steam generator was considered operable after the plugging of all tubes exceeding the plugging limit, now a steam generator shall be considered operable af ter either the plugging or sleeving in the af fected areas of all tubes exceeding the repair limit.
9.
TTS 4.4.5.5.a is changed to include in the 15-day report following each inservice inspection of steam generator tubes the number of 4
E LCA 187, Rev.1 Attachment A Page 2 of 4 sleeved tubes in each steam generator in addition to the number of plugged tubes in each steam generator.
10.
TTS 4.4.5.5.b.3 is changed to include in the annual report of the results of the steam generator tube inservice inspection the identi-fication of tubes sleeved in addition to the identification of tubes plugged.
11.
Table 4.4-2, " Steam Generator Tube Inspection", is changed in five places to indicate in appilcable " Action Required" blocks that defective tubes are to be plugged or now sleeved.
12.
TTS 3/4.4.5 Bases are changed as follows:
Third paragraph is changed to indicato that leaking steam gener-a.
ator tubes will be plugged or now sleeved in the affected area.
b.
Fourth paragraph is changed so that whereas plugging was required of all tubes exceeding the plugging limit, now plugging or sleeving in the affected area will be required of all tubes exceeding the repair limit.
Furthermore, plugging will be required of all tubes containing sleeves exceeding the repair lim 1L.
A new section is added to discuss steam generator sleeving and c.
to document the requirement that future sleeve designs must be approved by the NRC prior to their use.
Reason for Changes The TTS now requires that all defective steam generator tubes be plugged, Plugging tubes reduces reactor coolant flow and is less desi-rable in some casos than a repair technique that does not remove the tubes from service. The changes described above will allow sleeving of steam generator tubes as a corrective or preventive maintenance action.
Sleeving is a safe and effective procedure which does'not remove tubes from service.
Portinnd General Electric Company (PGE) has reviewed the sleeving designs-of a variety of vendore. Twa vendors have been selected for use at Troj an.
Reports which describe their sleeving designs and provide informatien to support their use are as follows:
1.
BAW-2094P, " Recirculating Steam Generators Kinetic Sleeve Qualification for 7/8-inch OD_ Tubes". October 1989.
2.
a.
BKAT-01-P, " Topical Report:
Repair of Defective Steam Generator Tubes by Sleeving", Revision 1. April 1989.
b.
EDR-TRJ-01-P. " Design Report:
Repair of Defective Steam Generator Tubes by Sleoving for Trojan Nuclear Power Plant",
October 1989.
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LCA 187, Rev. 1 Attachment A page 3 of 4 Determination of Sitnificant Hazards Considerations in accordance with the requirements of Title 10, Code of Federal Regulations (CFR), part 50.92, this License Change Application is judged to involve no significant hazards based upon the following information:
1.
Does the proposed license change involve a significant increase in the probability or consequences of an accident previously evaluated?
Some steam generator tubes have been found to have a varying amount of wall degradation. When the degradation is extensive, the normal practice of plugging defective tubes may reduce the effectiveness of the steam generators and eventually reduce the. performance of the nuclear steam supply system. An alternative to plugging tubes is instnlling a sleeve as a new pressure boundary inside the original tubes to bridge the degraded area, thus permitting the tubes to remain in service. The integrity of the steam generator tubes will be equivalent to that of an original tube.
In addition, the steam generator will remain capable of performing its required heat trans-fer function.
Therefore, the proposed change does not involve an increase in the probability or consequences of an accident previ-ously evaluated.
2.
Does the proposed license change create the possibility of a new or different kind of accident from any previously evaluated?
As discussed above, both the structural integrity and the heat transfer capability of the steam generators will not be signif1-cantly affected by the installation of sleoves.
In addition, the tube sleeves do not interact with any of the other plant syatoms.
Thus, the proposed change does not create the possibility of a new or different kind of accident from any previously evaluated.
3.
Does the proposed license change involve a significant reduction in a margin of safety?
The heat transfer capabilities of the steam generators will be improved by utilizing the sleeving process rather than the currently required plugging, since the reactor coolant system flow will not be reduced as much.
Furthermore, the structurk1 integrity of the steam generators wiJi. not be degraded. Therefore, the proposed change does not involve a reduction in a margin of safety.
Safety / Environmental Evaluation Safety and environmental evaluations were performed as required by 10 CFn 50 and the TTS.
The review determined that the proposed change does not create an unreviewed safety question, nor does it create an unreviewed environmental question, l
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LCA 187, Rev. 1 Attachment A Page 4 of 4 Schedule Consideration Prin.ary water stress corrosion cracking (PWSCC) resulted in the plugging.
of a signific.mt number of steam generator tubes during Trojan's 1989 Refueling Outtgo. A number of corrective actions are 1eing taken to arrest the further development of PWSCC; however, there exists a real possibility that the number of tubes required to be plugged during the 1990 Refueling outage could exceed the presently analyzed limit of 11-1/2 percent uniform tube plugging.
Therefore, to address this contin-gency, PGE desirts that the NRC review and approve this proposed license change by April 26, 1990 and make the effective date May 2, 1990.
l LGD/bsh 4516W.0490-1