ML20092A243
| ML20092A243 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 06/15/1984 |
| From: | Beckham J GEORGIA POWER CO. |
| To: | Stolz J Office of Nuclear Reactor Regulation |
| References | |
| GL-84-11, NED-84-305, TAC-54169, TAC-55600, TAC-55601, NUDOCS 8406190113 | |
| Download: ML20092A243 (5) | |
Text
Gceg:a Power Cormany 333 P:ecmont Avev Atlanta Georcia 30308 Te!ephone 404 526-7020 VaAng Address-Post Office Box 4545 At!araa Georg a 30302 Georgia Power
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J. T. Beckham, Jr.
Wce Pres' dent and General Manr&er NED-84-305 Nuctcar Gerieratten June 15, 1984 Director of Nuclear Reactor Regulation Attention: Mr. John F. Stolz, Chief
_ Operating Reactors Branch No. 4 Division of Licensing U. S. Nuclear Regulatory Ccmnission Washington, D. C.
20555 NRC DOCKETS 50-321, 50-366 OPERATING LICD1SES DPR-57, NPF-5 ENIN I. HA'ICH NUCLEAR PIRTT UNITS 1, 2 RESPONSE 'IO NRC IEITER 84-11 Gentlenen:
Pursuant to the requirenents.of NRC Generic Letter 84-11 dated April 19, 1984 concerning the inspection of BWR stainless steel piping, Georgia Power Canpany hereby subnits its current plans relative to inspections for intergranular stress corrosion cracking and leakage detection.
Enclosed as Attacheents 1 and 2 are the responses for Hatch Units 1 and 2, respectively.
Should you have any questions in this regard, please contact this office.
J. T. Beckhan, Jr. states that he is Vice President of Georgia Power Ccrapany and is authorized to execute this oath on behalf of Georgia Power Canpany, and that to the best of his knowledge and belief the facts set forth in this letter are true.
GBORGIA POWER OCMPANY B
p J. T. Beckhan, Jf.
Sworrf to and r bed before me this 15th day of June,1984.
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as, ms Enclosure xc:
H. C. Nix, Jr.
Senior Resident Inspector J. P. O'Reilly, (NRC-Region II) 8406190113 840615
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A'ITACINEN1' 1 Hatch Unit 1 Response to NRC Generic Letter 84-11 By letter dated May 31, 1984, Georgia Power Cmpany subnitted to NRC, as reluired by your letter dated February 11, 1983, its proposed inspection plans for the Hatch Unit 1 Fall 1984 maintenance / refueling outage.
These proposed plans meet the intent of the NRC staff's reconnended actions as identified in NRC Generic Letter 84-11 dated April 19, 1984.
t Pursuant to the requirenents of NRC Generic Letter 84-11, we wish to address the following itens relative to Hatch Unit 1:
(a) Scope and schedule of planned inspections Please refer to Enclosure 1, Section 2.1 of our May 31, 1984 letter.
%at particular section addresses the proposed scope of exminations for the stainless steel recirculation, RHR, and RWCU piping welds at Hatch Unit 1 and schedule thereof.
(b) Availability and qualification Please refer to Enclosure 1, Section 2.2 of our May 31, 1984 letter.
That particular section addresses the inspection procedure to be used during the examination of the subject piping and personnel qualification. Availability of exanination personnel is not expected at this time to be a problen as contract personnel will be used in addition to the exanination personnel of Southern Canpany Services' Inservice Inspection Group.
(c) Description of any special surveillance measures, in effect or proposed, for primary systen leak detection, beyond those measures reluired by Technical Specifications Please refer to Enclosure 1, Section 2.5 of our May 31, 1984 letter.
That particular section addresses leak detection and leakage limits for the next fuel cycle.
No measures above those identified in the aforementioned letter are planned at this time.
(d) Results of the Bulletin inspections not previously subnitted to NRC
%is iten is not applicable to Hatch Unit 1 since there have been no Bulletin inspections performed on the subject stainless steel piping welds since the Fall 1982 maintenance / refueling outage.
(e) Renedial measures, if any, to be taken when cracks are discovered Please refer to Enclosure 1, Section 2.4 of our May 31, 1984 letter.
That particular section addresses criteria for flaw evaluation and weld overlay repair.
%ese criteria are consistent with those specified in Attachnent 2 of NRC Generic Letter 84-11.
In addition, while there has been no cannitment made to NRC to replace the Hatch Unit 1 piping, replacement piping similar to that currently being installed at Hatch Unit 2 is on order should replacenent be necessary.
June 15, 1984 -
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ATTAODENr 2 Hatch Unit 2 Response to NRC Generic Letter 84-11 7
Since Georgia Power Company is currently in the process of replacing the existing stainless steel _ piping in the recirculation, RHR, and RWCU systens at Hatch Unit 2 with Type 316 Nuclear Grade piping, it proposes an
- alternative. approach as discussed herein to resolving any-future intergranular stress corrosion cracking (IGSOC) concerns as addressed in NRC Generic Letter 84-11.
As noted ' above, the existing piping material from the aforenentioned systens is'being replaced with nuclear grade piping material (Type 316 NG).
We RWCU piping is to replaced only to the inboard isolation valve thus allowing retention of the existing piping penetration.
We short length
'(approx. 6 ft.) of existing Class 1 BWCU piping fra the piping penetration
" flued head" to the outboard isolation valve will be retained.
Tentative plans during the current outage are to voltnetrically exanine the piping welds- (approx. 3 welds) of the retained piping and if no crack-like indications are observed, those particular welds would most likely be treated using see residual stress improvenent method, e.g., induction heat stress improvenent '(IHSI), last pass heat sink welding (LPHSW).
Although nuclear grade piping is being installed in the recirculation, RHR, and RWCU -systens, except as noted above, Georgia Power Capany has decided to IHSI the new piping welds as an additional countermeasure to preclude any possible future cracking of the piping due to IGSOC.
Pursuant to the requirenents of NRC Generic Ietter 84-11, we wish to address the following items relative to Hatch Unit 2:
(a) Scope and schedule of planned inspections since the piping in the recirculation, RHR, and RWCU systems is being replaced, except as noted above, with nuclear grade material and will be treated using IHSI, Georgia Power Capany feels that augnented inservice inspection - is no longer warranted. - Consequently, cmaencing with the next regularly scheduled maintenance / refueling outage, examinations of the new piping - will be performed in accordance with the schedule requirenents of the ASME Section XI Code, i.e., 25% of each pipe size in 10 years for Class 1 welds..
Should the retained section of the RWCU piping be free of crack-like indications and treated using sme residual stress improvenent method such as IHSI or LPHSW, future examinations would be conducted in a manner similar to that discussed above.
June 15, 1984 f
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'(b) Availability 'and qualification of exminers j
Availability of exmination personnel lis not foreseen as being a problen j
.at this time. Southern Canpany Services (SCS) most likely would perform the neceaaary inspections with assistance fran contract personnel, as l
~
. appropriate.
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%e process of qualification of all personnel who will perform i
. evaluations most likely would be that process presently in effect at the EPRI NDE Center. Currently, SCS.has in its scploy five Imvels II and f
iIII ipersonnel who have qualified at that facility by practical i
demonstration.
Nondestructive -'exmination personnel under contract to i
SCS who have qualified at ' the EPRI NDE Center in the detection and
.interI.retation of IGSCC may also perform 'exminations and evaluations, as appropriate.
i
. (c) Description of any special surveillance measures, in effect or proposed, I
for primari systen leak detection, beyond those measures already i
required by Tednical Specifications
- By letters dated May 25,' June 2, and June 7,1983, Georgia Power Canpany cannitted to augment reactor coolant leakage surveillance as a result of having observed unacceptable crack-like indications in recirculation and l
RHR piping' welds during - the Spring 1983 maintenance / refueling outage.
)
Your confirmatory order - dated July 8,
1983 acknowledged these cannitments and authorized plant restart.
%e cannitments made related to the auynented reactor coolant leakage surveillance meet the intent of the leak detection and leakage limits discussed in Attachnent 1 of NRC I
Generic Intter 84-11.
%e augmented. surveillance for reactor coolant leakage will' be retained as a measure of conservatian even though i
conforming piping material (as defined in NUREG-0313, Rev.1) is being l
used in the piping replacanent currently in progress.
In addition to - the above, a visual exanination for leakage of the t
reactor coolant piping will be performed during each plant outage in j
which - the contairunent is deinerted.
%e exanination will be performed j
consistent with, the reluirenants of In-5241 and In-5242 of the 1980 l
Riition of the AEME Section XI Code. ' %e 'systen boundary subject to l
this examination will be in accordance with IE-5221.
%is exanination is consistent with that-identified in Attachnent 1 to NRC Generic Letter
.84-11.
i (d)- Results of the Bulletin inspections not previously subnitted to NRC l
h
%is iten is not applicable to Hatch Unit 2 since there have been no Bulletin inspections conducted on the subject stainless steel piping i
since the Sprini 1983 maintenance / refueling outage.
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June 15, 1984.
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(e) Remedial measures, if any, to be taken when cracks are discovered Although the existing piping-is being replaced with nuclear grade material, except as noted above, -and is to be treated using IHSI, future cracking, although unlikely, could possibly occur.
Should IGSOC occur in the new material, renedial measures have not been determined at this time.
With regard to renedial measures for the retained section of Class 1 BWCU piping as described
- above, should unacceptable crack-like indications be observed, that particular section of piping would most
~ likely be replaced with nuclear grade material and installed using same residual stress improvenent method, e.g.,
IHSI, LPHSW, etc.
June 15, 1984 )
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