NUREG-0577, Forwards Request for Addl Info Re Low Fracture Toughness Since Facility Has Been Classified as Group 1 According to NUREG-0577.Response Should Be Submitted within 30 Days of Receipt of Ltr.Further NRC Evaluation Will Be Required
| ML17340A085 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 07/29/1980 |
| From: | Novak T Office of Nuclear Reactor Regulation |
| To: | Robert E. Uhrig FLORIDA POWER & LIGHT CO. |
| References | |
| NUDOCS 8008120019 | |
| Download: ML17340A085 (13) | |
Text
DISTRIBUTION JULY 9
NRC PDRs (2)
Local PDR TERA NSIC NRR:Reading ORBl Reading TsE Nova'k Dr. Robert E< UhÃg, Vice President S.
Varga Adaanced Systems and Technology C. Parrish Florida Power and 'Light Company M. Grotenhuis Post Office Box 529100 I8E (3)
Miami, Florida 33152
- Attorney, OELD J. Fair
Dear Dr. Uhrig:
J.
Ol s hins ki J. Heltemes Your letter of November 10, 1978 (L-78-355) responded to our letter of tfay 18, '1978 which requested information concerning the fracture tough>>
ness and potential for lamellar tearing of steam generator and reactor coolant pump support materials for the Turkey Point Plant Unit Nos.
3 and 4.
On Hay 19, 1980 we sent you a letter which discussed the comment copy of NUREG-0577 and solicited comments by July 7, 1980 (later extended to July. 21, 1980).
This letter also indicated that, although the Turkey Point Plant had not been reviewed in t$me to include the results
$ n the comment copy of NUREG-0577, it was then under review.
Docket Nos. 50-250 and 50-251 Sincerely, The above mentloned review has been completed and the Turkey Point facilities are classified as Group 1 according to NUREG-0577.
Therefore, further evaluation of the adequacy of the steam generator and reactor coolant pump supports will be required.
Enclosed is a request for the additional information which will be needed for our review.
lte request that you respond wfthln 30 days from the receipt of this letter.
Enclosure:
Request for Additional 1nformation cc:
w/enclosure See next page 8008~8 OO/9 44 A
~~g g+IIE4 Thomas tI. Novak, Assistant Director for Operating Reactors Division of Licensing OFFICE $
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sURNAME DATE$
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MGroten uis 07/I/ /80:jb Va 07
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'OR 07/~80 NRC FORM'318 (9 76) NRCM 0240 AU.S. GOVERNMENT PRINTING OFFICE: 1979 289 369
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Cq UNITEDSTATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 Docket Nos.
50-250 and 50-251 July 29; 1980 Dr. Robert E. Uhrig, Vice President Advanced Systems and Technology Florida Power and Light Company Post Office Box 529100 Miami, Florida 33152
Dear 'Dr. Uhrig:
Your letter of November 10, 1978 (L-78-355) responded to our letter of May 18, 1978 which requested information concerning the fracture tough-ness and potential for lamellar tearing of steam generator and reactor coolant pump support materials for the Turkey Point Plant Unit Nos.
3 and 4.
On May. 19, 1980 we sent you, a l,etter which discussed the comment copy of NUREG-0577 and solicited comments by July 7, 1980 (later extended to July 21, 1980).
This letter also indicated that, although the Turkey Point Plant had not been reviewed in time to include the results in the comment copy of NUREG-0577, it was then under review.
The above mentioned review has been completed and the Turkey Point facilities are classified as Group 1 according to NUREG-0577.
Therefore, further evaluation of the adequacy of the steam generator and reactor coolant pump supports will be required.
Enclosed is a request for the additional information which will be needed for our review.
Me request that you respond within 30 days from the receipt of this letter.
A Sincerely, Thomas M. Novak, Assistant Director for Operating Reactors Division of Licensing
Enclosure:
Request for Additional Information cc:
w/enclosure See next page
41
Robert E. Uhrig Florida Power and Light Company Duly 29, 1980 CC:
Mr'obert Lowenstein, Esquire Lowenstein,
- Newman, Reis and Axelrad 1025 Connecticut Avenue, N.W.
Suite 1214 washington, 0.
C.
20036 Environmental and Urban. Affairs Library Flori da International University Miami, Florida 33199 Mr. Norman A. Coll, Esquire
- Steel, Hector and Davis
.1400 Southeast First National Bank Building
'iami, 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 Comrission Post Office Box 971277 quail Heights Station Miami, Florida 33197
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REQUEST FOR ADDITIONALlNFQRMATION LOW FRACTURE TOUGHNESS
'LORIDA POWER AND LICHT CONPANY TURKEY POINT UNITS 3 AND 0 NRC DOCKET NO.
50-250 AND 50-52~
NRC TAC NO.
Oo793 AND OS794
ITM 1 CONCERN Figures 6 and 7,
[Bechtel Drawing numbers 5610-C194 (Rev.
- 3) and 5610-C196 (Rev. 3), respectively]
accompanying Florida Power and Light Company's letter of Nov. 10, 1978 to NRC, show the S/G and RCP support columns are laterally braced, at the top, to compartment walls.
Ho. 18 rebar extends out from embedment to act as studs to secure the bracing.
These zebaz are ordered to ASTM A-432, a specification that does. not assure fracture roughness.
These zebar appear to be simultaneously:,
1)
Important to support structure integrity 2) 3)
Of relatively poor fracture toughness Thick and notched by threads two conditions individually notorious as promoters of brittle
- behavior, and 4)
Not readily inspectable.
On the other hand, the zebar pattern (16 bars per support) provides considerable redundancy, and design stresses are not obviously excessive.
~RZ UEST In order that the fracture toughness adequacy of these rebar may be evaluated, please provide:
a)
Results of inspections of the rebar made to date and plans (if any) for future inspections.
State how such inspections are performed and what region of the rebar is so inspected.
P b)
Provide evidence to assure that all thermal expansions are actually being fully accommodated by the, mechanisms the de-sign provides foz this purpose.
Results of past inspections of wear in and around thermal expansion slots may provide acceptable evidence on this point.
Discuss such wear patterns in relationship to the possibility that rebar might be subjected to anticipated cyclic thermal loads during routine plant operations.
c)
Hill test reports for the heat(s) for this rebaz.
1nclude also any special ordering requirements and results of any other tests indicative of fzacture toughness that may have been performed.
If it is found that no relevant evidence is available under Items (a) and (c) above (i.e., if rebar fracture toughness is unknown and inspections are not made), testing of rebar
- samples, may become necessary.
Preferred sources of samples are 'materials possibly retained at the plant from original construction or at the mill from the same heat. If not otherwise available, samples may have to be taken from the structure.
It is requested that a search for suitable sources of samples be made for this ASTM A-432 rebar and their availability be reported.
If no source is found, please identify locations in the structure where material for coupons (see ASTH A-370, Section 18 and 19 for required size and number) can best, be taken with least impact on structural integrity.
ITEN 2 CONCERN NUREG 0577 ranks steel specifications according to the fracture toughness of products typically supplied under each specification when no additional material requirements are included in the procurement order.
A Group II rating is assigned to specifications governing steel of intermediate fracture toughness.
NUREG 0577 also establishes NDT criteria to screen steels for their suitability for use in S/G and RCP supports.
Certain Group II steels meet these screening criteria in applications where members are thin, but fail them if members are thick.
Thus, although use of these steels in thin sections is acceptable, no outright sanction for thick section use is granted.
In such cases fracture-toughness adequacy must be evalu-ated for each specific application.
'Guidance as to methods, acceptable to NRC, for making such evaluations is also supplied by NUREG 0577.
The design of the supports for the Turkey Point nuclear power station, Units 3 and 4, incorporates thick section use of the following Group II steels which do not meet the NDT screening criteria:
1.)
ASm A-302 2.)
ASKS A;588
REQUEST In order that the fracture-toughness adequacy of such applications may be evaluated, please submit the following information:
a)
Identify all applications where these steels are used in thick sections.
An acceptable
'procedure for making such determinations is to use the formula:
t,
= 2.5(-
)
KID 2 yD Where:
oyD is the dynamic yield. strength of the steel.
KID is the nominal minimum assured fracture toughness of the steel in accordance with values supplied by NUREG 0577.
is the critical thickness.
In members thicker than t c'rittle (i.e., plane strain) behavior may be expected.
If adequately documented, other procedures may be employed in making this determination.
For example, if other K D values specific to the steel used:in the application are known from mill or other tests these may be used in lieu of values taken from NUREG 0577.
b)
For structual members found to be thick, please submit the following information.
1.
Hill test records for these members.
Any additional available information which may be indicative of fracture toughness (e.g.,
supplementary material specification requirements or other test results).
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2.
Identify which of the thick members is most highly stressed in tension on the thick section.*
Report the most severe primary stress and the most severe primary-plus-secondary stress found, the station at which these
- occur, and the loading combination(s) that produces them.
c)
Please furnish a fracture-toughness evaluation of the condition identified in Item (b, 2) above.
Guidance as to acceptable means for making this evaluation is provided by NUREG 0577.
- In making this determination consider each thick member individually.
For each, identify the loading combination which most highly stresses the thick material at its most critical station.
For example, if the member is a thick Flange I-Beam, the most highly stressed location in the Flange should be considered.
Compare these stresses among all members.
Only the results for the member found to most highly stressed need be reported.
CONCERN Enformation relating to welding practices was deemed insufficient to enable evaluation of their fracture-toughness adequacy.
MIIUEST For the following weld joints:
a.
Pump support assembly plat-to-plate weld
[MC 6 to MC 7 in unit 3 shown in detail M in Pig.
24 (Dwg. 1428588) ]
b.
Column web and flange welds to plate MC 6 in units 3 of Pig.
24 (Dwg. 142858K) c.
Steam generator column web and flange welds to plate in Section G of Pig.
7 d.
Steam generator plate-to-plate weld in Section C of Pig.
7 (similar to Item a above)
Please furnish the following information:
a.
What specific welding materials were used (electrode type and
- diameter,
.add Q.ux'.i'f applicable)
- b. What welding conditions were used (position, current, and voltage)
- c. What welding sequence was used (which sections or sides were welded first, last, etc., during welding?)
d.
What post weld heat treatment was used (time, temperature) and how was this done?
How was the temperature monitored?
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