ML19344D690
| ML19344D690 | |
| Person / Time | |
|---|---|
| Site: | Pilgrim |
| Issue date: | 04/07/1980 |
| From: | Ippolito T Office of Nuclear Reactor Regulation |
| To: | Andognini G BOSTON EDISON CO. |
| References | |
| NUDOCS 8004280027 | |
| Download: ML19344D690 (4) | |
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'o UNITED STATES g
NUCLEAR REGULATORY COMMISSION y '^, e g
WASHINGTON, D. C. 20555 s, -
- y april 7
1980 Docket No. 50-293 Mr. G. Carl Andognini Boston Edison Company M/C NUCLEAR 800 Boylston Street Boston, Massachusetts 02199
Dear Mr. Andognini:
During our continuing review of the Pilgrim Unit 1 GE turbine inspection findings, we have found it necessary to request that the following infor-mation be supplied on a schedule that will provide for review prior to startup from the current refueling outage.
1.
Description of the turbine disc inspection procedure 2.
Inspection results 3.
Justification for returning to power with UT indications (.i.e.
water cutting) 4.
Responses to the enclosed questions.
Some of this information may have been supplied in a GE submittal dated March 27, 1980. To the extent that it is applicable to Pilgrim Unit 1, the GE document may be referenced.
Since the basic NRC concern about turbine disc cracking is the potential for interaction with safety related systems and components in case of a turbine failure, it would be prudent to perform an assessment of the potential for turbine missile damage at the Pilgrim Unit 1 facility.
Accordingly, please provide a schedule for your planned submittal of an analysis of strike and damage probabilities with your response to this request for information.
(See Question VI in enclosure.)
Sincerely, ito, Chief Operating Reactors Branch #3 Division of Operating Reactors
Enclosure:
Request for Information Related to Turbine Discs cc w/ encl:
See next page 7
8004280 O2T
Mr. G. Carl Andognini
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Boston Edison Company cc:
Mr. Paul J. McGuire Pilgrim Station Acting Manager Boston Edison Company RFD #1, Rocky Hill Road Plymouth, Massachusetts 02360 Henry Herrmann, Esquire Massachusetts Wildlife Federation 151 Tremont Street Boston, Massachusetts 02111 Plymouth Public Library North Street Plymouth, Massachusetts 02360 i
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. rovide the following infcrmatier fcr each L? turbir.e:
Turbine type A.
3.
Number of hours of operation fcr each L? turbine at time of last turbine inspecticn or if not inspected, postulated to turbine inspection Number of turbine trips and oversp)eeds C.
For each disc: (With UT indications D.
1.
type of material including caterial specifications 2.
tensile properties data 3.
toughness p'ropertie's data including Fracture Appearance Transition Temperature and Charpy upper steel enercy and temperature 4.
keyway temperatures 5.
critical crack size and basis for the calculation 6.
calculated bore and keyway stress at operating design overspeed 7.
calculated Ki data 5.
minitum yiele strsngth s;ecified for each disc II.
Fr: vide details of the rssults of any completed inservice inspection cf
' ? turbir.e r rs, includinc areas examir.ed, sir.:e issuance of an :;eratino
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'icense.
For each indication de: acted, previde de ails of the loca:icr.
of the indication, its orien atica, size, and postulated cause.
Provide the nominal water chemis:ry conditions for each LP turbine and
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III.
describe any condenser inieakages or other significant changes in water chemistry to this point in its 0;arating life.
I..
- y ur pian has n:t been ins;e: ed, describe your proposed schedule a-d i:proach o er.sure that turbine cra: king dess not exist in your turbir.e.
If your plant has been inspected and plans to return or has returned t:
- wer with cracks or other defec s, provide your prooosed schedule for the next turbine inspection and the basis for this inspection schedule, including postulated defect growth rate.
'! I.
Indicate whether an analysis and evaluation regarding turbine missiles have been performed for your piar.
and pr:vided to the staff.
If such an analysis and evaluation has been performed and reported, please provide a:prepriate references to the available d:cumentation.
In the event that such s:cdies have nc been ade,.consideratica should be given to scheduling su:h an action.
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JE!EE:: 7;E57IC.'?5 - T: Ee C: leted in 3 0 Days I.
25s: ribe t. hat quality c:ntrol and inspecti:n pr:cedures are used for the disc bore and keyway areas.
II.
Provide details of the General Electric repair / replacement procedures f r faulty discs, III.
ilhat immediate and long term actions are being taken by General Electric to minimize future " water cutting" problems with turbine discs?
What a:ticas are bein; recommended to utilities to minimize " water cutting" of discs?
IV.
Describe f' abrication and heat treatment secuence for discs, including thertal exposure'during shrinking operations.
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