ML20245B675
| ML20245B675 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 06/19/1989 |
| From: | Cockfield D PORTLAND GENERAL ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| IEB-89-001, IEB-89-1, NUDOCS 8906260013 | |
| Download: ML20245B675 (5) | |
Text
,
- ummm, muse Portlanc!W ElectiicCciriprzy.
David W. Cockfield Vice President, Nuclear June 19 1989 Trojan Nuclear Plant-Docket'50-344 Licchse NPF-1 U.S. Nuclear Regulatory Commission.
Attn: Document Control Desk Washington DC 20555
Dear Sir:
Nuclear Regulatory Commission Bulletin (NRCB) 89-01,
" Failure of Westinghouse Steam Generator Tube Mechanical Plugs" Nuclear Regulatory Commission-(NRC)Bulletin 89-01 requests that-operating pressurized water reactor licensees determine whether certain mea.hanical plugs supplied by Westinghouse are installed in their steam generators and, if so, that an action plan be implemented to ensure that these plugs will continue to provide adequate assurance of reactor coolant system pressure boundary integrity under normal operating, transient, and postulated accident conditions, i
1 Mechanical plugs from the heat numbers of concern are installed in the i
steam generators at the Trojan Nuclear Plant. Attached is a summary of our.
i t.
i i
8906260013 890619
/gg PDR ADOCK 05000344 4
Q PDC
^<,
4
' 121 S.W Sa!rron Street, Pomand, Oregon 97204
,k l
Portlard General BecticCars.uty Document Control Desk June 19, 1989 page 2 actions to address the specific items requested in this bulletin. We would be pleased to answer any questions you have concerning this response.
Sincerely, i
Attachment c:
Mr. John B. Martin Regional Administrator, Region V U.S. ' Nuclear Regulatory Ccmunission Mr. William T. Dixon State of Oregon Department of Energy Mr. R. C. Barr NRC Resident Inspector i
Trojan Nuclear Plant Subscribed and sworn to before me this 19th day of June 1989.
O,M!4-(; f,
.n/gfehr d
Notary Public of. Oregon My Commission Expires:
d '/4We[
/
w l
i
l i
)
Trojan Nuclear Plant Document Control Desk Docket 50-344 Attachment I
License NPF-1 June 19, 1989 f
Page 1 of 3 j
1 PORTLAND GENERAL ELECTRIC COMPANY (PGE) l
SUMMARY
OF EVALUATION OF i
NUCLEAR REGULATORY COMMISSION (NRC) BULLETIN 89-01 I
l Requested Action 1 Verify that information contained in Westinghouse Reports WCAP-12244 and I
WCAP-12245, " Steam Generator Tube Plus Integrity Summary Report",
j Revision 1, and Westinghouse letter to the NRC, " Steam Generator Tube i
Plug Integrity Update", dated May 1, 1989, relating specifically to the f
Trojan Plant is correct for plugs supplied from Heat Numbers 3279, 3513, j
3962, and 4523. The specific information to be verified is the number of Westinghouse mechanical plugs installed in the hot and cold legs broken down by steam generator number, heat number, and date of installation.
If information from these references is incorrect, appropriate corrections should be identified.
So state if PGE has not installed Westinghouse mechanical plugs from the subject heats.
PGE Response j
PGE has verified the information contained in the referenced Westinghouse
{
documents as being correct.
Eighty-two mechanical plugs from Heat j
Number 3962 are installed in the Trojan Plant steam generators.
No
{
mechanical plugs from Heat Numbers 3279, 3513, and 4523 have been installed at Trojan.
l Requested Action 2 l
Take the following actions, to be,mplemented initially during the current refueling outage and during all future refueling outages:
Steam generator tube plug lifetime for plugs from Heat 3962 should a.
be estimated using the methodology from WCAPs 12244 and 12245 and Westinghouse letter to the NRC, dated May 1, 1989, and should be based on on the Millstune Unit 2 benchmark.
PGE Response The steam generator tube plug lifetimes for Heat Number 3962 are negative 301 equivalent full-power days (EFPD) for hot leg plugs and positive 2226 EFPD for cold leg plugs, based on Millstone Unit 2 benchmark data, b.
Implement appropriate remedial actions (i.e., repair and/or replacement) for all plugs whose estimated lifetimes do not extend to the next refueling outage.
Trojan Nuclear Plant Document Control Desk Docket 50-344 Attachment License NPF-1 June 19, 1989 Page 2 of 3 PGE Response PGE has repaired the eighty-two plugs from Heat Number 3962.
Repairs were effected using Babcock and Wilcox Plug-A-Plug (PAP) methodology, which is similar to and functionally equivalent to the Westinghouse Plug-In-Plug (PIP) design.
c.
Prior to any plus repairs or replacement PGE is reminded that their responsibilities under As-Low-As-Reasonably-Achieveable (ALARA) philosophy require analysis of the various plug repair or rep.?acement methods available to determine which method will result in the lowest overall personnel radiation exposure while still remaining cost-effective.
In choosing a plug repair or replacement method, PGE should consider the accessibility of the plugs and the dose reduction benefit of using robotic manipulators. Prior to plus repair or replacement, PGE should consider steam generator decontamination and/or local shielding to reduce working area dose rates.
PGE Response PGE analyzed potential plug repair or replacement techniques in accordance with ALARA responsibilities. The Babcock and Wilcox Plug-A-Plus concept was selected, in part, because it could be accomplished using the remotely operated generator examination and repair (ROGER) manipulator system, d.
Installation of Westinghouse mechanical plugs from Heats 3279, 3513, 3962, and 4523 should be discontinued.
PGE Response No mechanical plugs from these heats will be installed at Trojan beyond those currently installed plugs which have been repaired this refueling outage.
Westinghouse mechanical plugs removed from steam generators, e.
regardless of heat number, should be examined for primary water stress corrosion cracking (PWSCC) on a sample basis for each heat.
Ma:"tain a record of these examinations, and the results should be provided to Westinghouse to improve the data base concerning the susceptibility of plugs to PWSCC.
PGE Response PGE does not plan to remove any Westinghouse mechanical plugs from the Trojan steam generators during this refueling outage.
If such plugs are removed du-ing the next five operating cycles, they will be examined as requested.
Records of these examinations will be maintained and the results will be provided to Westinghouse.
Trojan Nuclear Plant Document Control Desk Docket 50-344 Attachment License NPF-1 June 19. 1989 Page 3 of 3 Requested Action 3 Remedial actions at plants where the steam generator tubes are partially-depth-expanded within the tubesheet may be deferred on a i
one-time basis to the nes:t scheduled refueling outage.
PCE Response All remedial actions have been taken during the current refueling outage as explained in the PGE Response to Requested Action 2.b.
Requested Action 4 Remedial actions for " sentinel related" mechanical plugs may be deferred on a one-time basis to the next refueling cutage.
PGE Response All remedial actions have been taken during the current refueling outage as explained in the PGE Response to Requested Action 2.b.
LCD/mjs 3206W.0689 1
_ _ _ _ - _ - _.