ML20245E783
| ML20245E783 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 06/19/1989 |
| From: | William Cahill TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| IEB-89-001, IEB-89-1, TXX-89414, NUDOCS 8906270443 | |
| Download: ML20245E783 (5) | |
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Log # TXX-89414 File # 10119 Ref. # NRCB 89-01 1UELECTRIC June 19, 1989 William J. Cahill. Jr.
I.netutwe s'sce bewime U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C.
20555
SUBJECT:
COMANCHE PEAK STEAM ELECTRIC STATION (CPSES)
DOCKET NOS 50-445 AND 50-446 l
NRC BULLETIN N0. 89-01:
FAILURE OF WESTINGHOUSE STEAM GENERATOR TUBE MECHANICAL PLUGS l
REF:
- 1) Westinghouse Report WCAP-12244, Revision 1:
Steam Generator Tube Plug Integrity Summary Report, dated April 1989 (Proprietary)
- 2) Westinghouse Letter NS-NRC-89-3432, Steam Generator Tube Plug Integrity Update.
dated t<ay 1, 1989 Gentlemen:
TU Electric has evaluated the concerns of the subject bulletin.
The reporting requirements of the bulletin state that:
" Addressees shall submit a letter within 30 days of receipt of this oulletin containing:
1.
The ir. formation under Antiong Recuested, item 1.
2.
A commitment to Actions Reauested, items 2, 3, and 4 or proposed alternative actions with supporting justification."
In accordance with these requirements the following response is submitted.
Action Item 1 Addressees are requested to verify that information contained in References 1) and 2) relating specifically to their plants is correct for plugs supplied from heat numbers 3279, 3513, 3962, and 8523. The specific information to be verified is the number of Westinghouse mechanical plugs installed in the hot and cold legs broken dovn by steam generator number, heat number, and date of installation.
If information from these references is incorrect, appropriate ccerections should be identified. Addressees are requested to so state if their plents have not installed Westinghouse mechanical plugs from the subject heats.
G m monk ofwe strrer ut 81 Dana,, Trzas mot
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TXX-89414 June 19, 1989 Page 2 of 4 i
TV Electric ResDonse References 1) and 2) indicate that Westinghouse has not supplied plugs from heat numbers 3279, 3513, 3962 and 4523 to CPSES.
Based on a review of CPSES 3
records, TU Electric has verified that plugs from the subject heat numbers
{
have not been received or installed at CPSES.
Action Items 2(a). (b). and (c)
Addressees are requested to take the following actions, to be implemented initially during any refueling outage or extended outage (greater than four weeks) which ends 30 days or more following receipt of this bulletin and during all future refueling outages.
a) Steam generator tube plug lifetime for plugs from heats 3279, 3513, 3962, and 4523 should be estimated using the methodology from References 1) and
- 2) and should be based on the Hillstone Unit 2 benchmark subject to any corrections per item 1 above.
Lifetime estimates in Reference 2) for plugs fabricated from heat 4523 are based on the Farley Unit 2 benchmark.
These estimates should be adjusted to reflect the Millstone Unit 2 benchmark using the methodology described in Section 4.1.2 of Reference 1).
b) Addressees should implement appropriate remedial actions (i.e., repair and/or replacement) for all plugs whose estimated lifetimes in 2a, above i
do not extend to the next refueling outage.
If operation is planned i
beyond a refueling outage that represents the last outage before any plug exhausts the predicted lifetime, an alternative schedule with the appropriate technical justification should be submitted to the NRC at
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least 30 days before the end of this refueling outage, i
i C) Prior to any plug repairs or replacement, addressees are reminded that j
their responsibilities under ALARA require analysis of the various plug j
repair or replacement 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, the licensee should consider the accessibility of the plugs and the dose reduction benefit of using robotic manipulators.
Prior to plug l
repair or replacement, the licensee should consider steam generator i
decontamination and/or local shielding to reduce working area dose rates.
l TV Electric Response 1
As stated in the response to Action Item 1, CPSES records indicate that plugs from the subject heat numbers have not been installed at CPSES. Therefore, calculation cf plug lifetimes and implementation of remedial actions for these i
heats is not applicable to CPSES.
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TXX-89414 June 19, 1989 Page 3 of 4 Action Item 2(d)
Installation of Westinghouse mechanical plugs from heats 3279, 3513, 3962, and 4523 should be discontinued.
TV Electric Response TV Electric has taken action to assure that plugs from the subject heats are not procured in the future.
As stated in Reference 1), for any new installation Westinghouse will only provide mechanical plugs with a preferred microstructure.
l Action Item 2(e)
Westinghouse mechanical plugs removed from steam generators, regardless of heat number, should be examined for PWSCC on a sample basis for each heat.
Addressees should maintain a record of these examinations and the results should be provided to Westinghouse to improve the database concerning the susceptibility of plugs to PWSCC.
TV Electric Response TV Electric has initiated action to prepare the procedure change (s) necessary to implement Action Item 2(e). The procedure changes will be issued no later than July 31, 1989.
Action Items 3 and 4 3.
Remedial actions at plants where the steam generator tubes are partially depth-expanded within the tubesheet as described above may be deferred on a one time basis to the next scheduled refueling outage if the outage that immediately follows receipt of this bulletin ends before October 1, 1989.
4.
Remedial actions for "sentin91 related" mechanical plugs described above may be deferred on a one time basis to the next refueling outage if the outage that immediately follows receipt of this bulletin ends before October 1, 1989.
TV Electric Response As stated in the response to Action Item 1, CPSES records indicate that plugs from the subject heat numbers have not been installed at CPSES.
Therefore, these Action Items are not applicable to CPSES.
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Lj TXX-89414 June 19, 1989 Page 4 of 4 General 1
i An attachment is provided of the required affidavit in accordance with the 1
reporting requirements of NRC Bulletin 89-01 that responses be submitted _
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under oath or affirmation under the provisions of Section 182a, Atomic Energy i
Act of 1954, as amended.
l TU Electric is aware that additional concerns regarding steam generator tube l
plugs are being evaluated by Westinghouse. We will monitor the progress of i
these evaluations and will submit additional reports if. required (e.g.', by 10CFR50.55(e)).
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Sincerely, 9
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/
l William J. Cahill, Jr.
HAM /ddm Attachment c - Mr. R. D. Martin, Region IV Resident Inspectors, CPSES (3)
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Attachment to TXX-89414 June 19, 1989 Page 1 of 1 UNITED STATES OF AMERICA NUCLEAR REGULATORY C0HHISSION In the Matter of
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Texas Utilities Electric Company
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Docket Nos. 50-445
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50-446 (Comanche Peak Steam Electric
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Station, Units 1 & 2)
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W. J. Cahill, Jr. being duly sworn, hereby deposes and says that he is Executive Vice President, Nuclear of TU Electric, the Applicant herein: that he is duly authorized to sign and file with the Nuclear Regulatory Commission this response to NRC Bulletin 89-01: that he is familiar with the content thereof: and that the matters set forth therein are true and correct to the best of his knowledge, information 7.nd belief.
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',,9 W.J[p6 hill,Jr.
ExecuYive Vice President, Nuclear STATE OF TEXAS
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COUNTY OF DALLAS
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Subscribed and sworn to before me, a Notary P blic in and for d lA/44-
, on this
/4 6C day of
,h_ e_
, 1989.
Notary Public Hy commission expires:
/0!#3.
PATRICIA WILSON
- )
w cowesa ramts k
March 16,1993
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