ML17341A790
| ML17341A790 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 12/18/1981 |
| From: | Novak T Office of Nuclear Reactor Regulation |
| To: | Robert E. Uhrig FLORIDA POWER & LIGHT CO. |
| References | |
| NUDOCS 8201110748 | |
| Download: ML17341A790 (7) | |
Text
0 SSc 1 8 88'ocket No. 50-251 Dr. Robert E. Uhrfg, Vice President Advanced Systems and Technology Florida Powei and Light Company Post Office Box 529100 Hfami, Florida 33152
Dear Dr. Uhrfg:
DISTRIBUTION:
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- R'NQ Ife have reviewed your "60 day" response dated October 31, 1981, I
letter dated August 21, 1981, concerning Pressurfzed Thermal St>ock Enclosure 1 to this letter identifies additional information needed as a
result of our review.of your response.
Me request that the additional information identified in Enclosure 1
be provided with your "150-day" response to our August 21 letter.
In addition, we have been assessing what information will be provided in the "150-day" responses due in January 1982 and the fnformation expected to be supplied from the PHR Owners'roup.
Since the staff is committed to provide its recommendations for further actions regarding PTS to the Commission in the Spring of 1982, it fs(iijportant that your "150-day" response to our August 21 letter provide two significant..pieces. of informa-,
tion.
First, you must provide your basis for(continued operation, pending completion of any longer term studies.
He emphasize that continued operra-tion of your facility, without any immediate modifications to your facility or its operation, will be dependent upon our evaluation of your response.
- Secondly, your response should fully address the information addressed in.
Me have prepared Enclosure 2 to provide amplification to the "150-day" information request of the August 21, 1981 letter.
The additional information requested by the letter should be provided in accordance with 10 CFR 50.54(f) of the Commission' regulations.
The reporting and/or recordkeeping requirements of this letter affect fewer than ten respondents; therefore, OMB clearance is not required under P.L.96-511.
Sincerely, 820iii0748 8ii2i8 PDR ADOCK 0500025i P
Enclosures:
ORIGINALSIGIL Thomas Il. Novak, Assistant Dfrector for Operating Reactors Division of Licensing
- see previous 318 for concurrence.
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12/
/81 OFFICE 0 SURNAME/
DATE0 Respons to 8/21/81 "2;"""A'Hip'f'i'0 'a'Oo'n-'o'-"'l5
Request,-to-S/21/81-I tr.
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OFFICIAL RECORD COPY USG PO. 19M~9.960
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Your assessment of the sensitivity of your analy~es to uncertainties in input values, silrh as initial crack size, copper content, fluerice, and inital reference temperatur e at wel ds.
(4)
A list of assumptions relied upon in reachin your conclusions.
- a. If this list includes "credit" for operator actions, describe the basic instructions 'given the operator (for example, if a "sub-cooling" band is used<
describe it).
Submit the procedures the operator will follow, 'and describe
)he training being given to establish operator readiness to cond with PTS events.
- b. If the list includes credit for the effects of warm prestressing for some event sequences, incluge your justification and analyses showing that such events will'f)liow a pressure-temperature path-way for which warm pre-stress is effective.
The reporting and/or recordkeeping req ir emeqts of this letter affect fewer than ten respondents; therefor OHB clearance is not required under P.L.96-511.
Sincerely,
Enclosure:
Evaluation of 60 Day
Response
to 8/21/81 IIRC 1tr. on PTS 8
Request for Additional Information cc w/enclosure:
See next page Thomas N. IIovak, Ass stant Director for Operating React rs Division of Licensing OFFICEI SURNAME IP OATE 0 ORBII1:DL "Cr'o penh'u'i's 12/ ( l/81 ORB//:
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NRC FORM 318 (10-80) NRCM 0240 OFFICIAL RECORD COPY USGPO:
$ 981 33rr.960
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Rober. E. Uhrig Florida Power and Light Company CC:
Mr. Robert Lowenstein, Esquire Lowenstein,
- Newman, Reis and'xelrad 1025 Connecticut Avenue, N.W.
Suite 1214 Washington, D. C.
20036 Environmental and Urban Affairs Library Florida International University Miami, Florida 33199 Mr. Norman A. Coll, Esquire
- Steel, Hector and Davis 1400 Southeast First National Bank Building Miami, Florida 33131 Mr. Henry Yaeger, Plant Manager Turkey Point Plant Florida Power and Light Company P. 0.
Box 013100 Miami, Florida 33101 Mr. Jack Shreve Office of the Public Counsel Room 4, Holland Building Tallahassee, Florida 32304 Administrator Department of Environmental Regulation Power Plant Siting Section State of Florida 2600 Blair Stone Road Tallahassee, Florida 32301 Resident Inspector Turkey Point Nuclear Generating Station U. S. Nuclear Regulatory Commission Post Office Box 1207 Homestead, Florida 33030
ENCLOSURE (1)
EVALUATION OF THE FLORIDA POWER AND LIGHT COMPANY 60 DAY RESPONSE TO TH NRC LETTER DATED AUGUST 21, 1981 CONCERNING PRESSUREIZED THERMAL SHOCK (PTS)
AND REQUEST FOR ADDITIONAL INFORMATION TURKEY POINT, UNIT NO.
4 DOCKET NO. 50-251 RTNDT Values We intend to use the initial RT>D values as provided in your letter dated October 21, 1981.
In arr(vying at a current RT T value for the girth welds of Unit 4 you provided a
ART value thkPwas based on Unit 3 surveillance test results.
fxtrag$cation of the APTU from the capsule fluence
(~8 x 10'0 n/cm
) to the present fluence l.l x 1010 n/cmt) was has'ed on the slope of the ASTM trend curve.
We cannot accept the idea that it is proper to use the Unit 3 surveillance test results in this way.
The following,discussion will disclose our reasons for that conclusion.
We are aware that the surveillance weld for Unit 3 had the same weld wire heat no.
(71249) and the same flux lot no.
(8445) as the beltline weld in Unit 4.
Also, that the surveillance weld in Unit 4 had the same weld wire heat number (71249) but a different flux lot no. (8457).
- However, we consider the Charpy shift to be primarily dependent on copper content and, therefore, on weld wire heat number.
- Thus, we have two surveillance results, both of which happen to be at ~8 x 1018 n/cm~
(according to the latest fluence estimates from FPImL) which show 30 ft. lb. shift values of 155'F and 225'F.
Copper content, from several measurements of the surveillance weld metal and broken Charpy bars ranged from 0.21 to 0.35 percent.
As part of the thermal shock studies, we have compiled a
PWR surveillance data base for the materials in question and drawn separate, tentative trend curves for high (0.5;. nominal) and low (0.2'ominal) nickel materials.
When the Unit 3, Capsule T surveillance result for the weld material is compared with the PWR data base, it appears to be an outlier, the measured shift being considerably lower than the mean for the data base at the fluence.
Based on th~ high tIickel curves, the predicted shift is 290'F for a fluence of 1.1 x 10 n/cm
, and copper content of 0.30% or greater.
(Being on the upper limit line, the trend curve for 0.30Ã and 0.35 o copper is the same).
Using Reg.
Guide 1.99, the., predicted shift is also 290'F.
In summary, the Unit 3 surveillance data are not sufficiently credible to provide the sole basis for estimation of hRTN Trend curves based on pertinent data are the alternative that must N used.
The MPC/ASTM upper bound curves have not been accepted by the NRC because they are not a very good upper bound of the data in the 1019 -n/cm~ fluence range.
The study of PWR surveillance data confirmed that Reg.
Guide 1;99 Rev.
1 is c~nservative, but not too conservative for fluence values near 1019 n/cm 2.
The Rate of Increase of RTNpT We have no disagreement with your answer to guestion 2, but should point out that although the 10 year average change in RT is 7'F, the change in one EFPY from today if ll'F, based on the MPC tJNd curves.
In addition please provide the rate of increase of RT per EFPY taking into consider-ation any contemplation changes in core %figuration.
3 5 4 RTqpT Limit and Basis for the Limit You have indicated in your letter dated September 23, 1981 that the response to Item 3 5 4 of the August 21 letter will be delayed until March 1, 1982.
Since the "60-day" responses from other licensees stated that PWR owners generally do not consider a limit on RT to be an appropriate basis for continued operation, the staff neK to develop a quantitative criterion for continued operation that, if implemented, would assure maintenance of an acceptably low risk of vessel failure from PTS events for the near-term, pending longer term results of more detailed analyses or research.
We will be developing this criterion, considering recommendation that you may provide in your 150 day response.
5.
Operator Actions The extent to which the overall concern of thermal shock is being emphasized at Turkey Point Unit No.
4 has been the subject of discussions between staff personnel (Project Manager and Resident Inspector).
From these discussions we are aware that PTS is addressed in training and the operators have experience in handling events which could lead to PTS and are sensitive to thermal shock consideration.
- However, we cannot determine from your "60-day" response to our letter of August 21, 1981, the degrees of emphasis which is currently planced on the need for changes in procedures, training and management involvement.
We request that you expand your response to provide us a more detailed discussion of what steps have been taken to ensure that your operators have a firm grasp of this issue and can be expected to cope with the events which serve to initiate PTS.