ML19276H545
| ML19276H545 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 11/27/1979 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | Rubenstein L Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19276H546 | List: |
| References | |
| NUDOCS 7911290389 | |
| Download: ML19276H545 (34) | |
Text
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TENNESSEE VALLEY AUTHORITY CH ArTANCCGA. rENNESsEr 37401 400 Chestnut Street Tower II November 27, 1979 Director of Nuclear Reactor Regulation Attention:
Mr. L. S. Rubenstein, Acting Chief Light Water Reactors Branch No. 4 Division of Proj ect Management U.S. Nuclear Regulatory Commission Washington, DC 20555
Dear Mr. Rubenstein:
In the Matter of the Application of
)
Docket Nos. 50-327 Tennessee Valley Authority
)
50-328 In response to your September 14, 1979, letter to H. G. Parris trans-mitting guide thimble tube wear questions, enclosed are forty (40) proprietary and twenty (20) nonproprietary copies of our answers to these questions. Also enclosed is a copy of Westinghouse's Application for Withholding Proprietary Information from Public Disclosuru.
As this submittal contains information proprietary to Westinghouse Electric Corporation, it is supported by an affidavit signed by Westinghouse, the owner of the information.
The affidavit sets fcret the basis on which the information may be withheld from public disclosure by the Commission and addresses with specificity the considerations listed in paragraph (b)(4) of Section 2.790 of the Commission's regulations.
Accordingly, it is respectfully requested that the information which is proprietary to Westinghouse be withheld from public disclosure in accor-dance with 10 CFR Section 2.790 of the Co= mission's regulations.
Corres-pondence with respect to the proprietary aspects of this application for withholding or the supporting Westinghouse affidavit should reference CAW-7 9-4(1. and should be addressed to R. A. Wiesemann, Manager, Re: ilatory and Legislative Affairs, Westinghouse Electric Corporation, P.O. Box 355, Pittsburgh, Pennsylvania 15230.
Very truly yours, TENNESSEE VALLEY AUTHORITY w
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L. M. Mills, Manager Nuclear Regulation and Safety Hf.e > *;y f
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Westinghouse Water Reactor wear reemen omsica Electric Corporation Divisiarts acess Pnns:;urt\\ Pertst taraa 152%
i November 7, 1979 CAW-79-40 M'r. H. R. Denton, Director Office of Nuclear Reactor Regulation U. S. Nucleat Regulatory Commission Washington, D. C.
20555 APPLICATI0ft FOR WITHHOLDIt!G PROPRIETARY INFORMATION FROM FUSLIC OISCLOSURE
SUBJECT:
Diablo Canyon, Units 1 and 2 (Cocket Numbers 50-275 and 50-323)
McGuire, Units 1 and 2 (Docket Numbers 50-369 and 50-370)
North Anna, Unit 2 (Cocket Number 50-339)
Salem, Unit 2 (Docket Number 50-311 Sequoyah, Units 1 and 2 (Cocket Numcers 50-327 and 50-323)
Responses to NRC Questions on Guide Tube Thimble Wear REF: Letter from TVA to L.
S.
Rubenstein dated Noveraber 27, 1979 Gentlemen:
This application for withholding is submitted by Uestinghouse Electric Corporation pursuant to the provisions of paragraph (b)(1) of 10CFR Section 2.790 of the Commission's Regulations.
The accompanying affidavit identifies the information sought to be withheld from public disclosure, sets forth the basis on which the information may be withheld from public disclosure by the Commission, and addresses witn specificity the considerations listed in paragraph (b)(4) of Section 2.790 of the Commission's regulations.
The undersigned has reviewed the information scuyht to be withheld and is authorized to apply for its withholding on behalf of '..'estinghouse, llRD, notification of which was sent to the Secretary of the Commission on April 19, 1976.
It is requested, therefore, that the Westinghouse proprietary information being transmitted by the involved utility letter referenced acove be withe held from public disclosure in accordance with the provisions of 10CFR Section 2.790 of the Commission's regulations.
S 9 22
Mr. H. R. Derton November 7, 1979 chW-79-40 Correspondence with respect to the proprietary aspects of this appli-c'Ition for withholding or the accompanying affidavit should reference CAW-79-40 and should be addressed to the undersigned.
Very truly yours, Robert A. Wiesemann,,anager Regulatory & Legislative Affairs
/bek Attachment cc:
J. A. Cooke, Esq.
Office of the Executive Legal Director O
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CAW-79-40 AFFIDAVIT COMM0mlEALTH OF PENNSYLVANIA:
ss COUNTY OF ALLEGHENY:
Before me, the undersigned authority, personally appeared Robert A. Wiesemann, who, being by me duly sworn accordir.g to law, deposes and says that he is authorized to execute this Affidavit on behalf of Westinghouse Electric Corporation (" Westinghouse") anc that the averments of fact set forth in this Affidavit are true and correct to the best of his knowledge, information, and belief:
UASALLC W Robert A. WTesem. inn, Manager Regulatory & Legislative Affairs Sworn ta and subscribed g
n bef re me this /
day of A4-* M W 979.
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6 G _A s b_ 2ttf Notary Public' M
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CAW-79-40
.. (1)
I am Manager, Regulatory and Legislative Affairs, in the Nuclear Technology Division, of Westinghouse Electric Corporation and as such, ' have been specifically delegated the function of reviewing the proprietary information sought to be withheld from public dis-closure in connection with nuclear power plant licensing or rule-making proceedings, and am authorized to apply for its withholding on behalf of the Westinghouse Water Reactor Divisions.
(2)
I am making this Affidavit in conformance with the provisions of 10CFR Section 2.790 of the Commission's regulations and in con-junction with the Westinghouse application for withholding accompanying this Affidavit.
(3)
I have personal kbowledge of the critaria and precedures utilized by Westinghouse Nuclear Energy Systems in designating information as a trade secret, privileged or as confidential commercial or financial information.
(4) Pursuant to the provisions of paragraph (b)(4) of Section 2.790 of the Commission's regulations, the following is furnished for consideration by the Commission in determining whetner the infor-
~
mation sought to be withheld from public disclosure should be withheld.
(i) ' The information sought to be withheld from public disclosure is awned and has been held in confidence by Westinghouse.
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, (ii) The information is of a type customarily held in confidence by Westinghouse and not customarily disclosed to the public.
Westinghouse has a rational basis for cetermining the types of information customarily held in confidence by it and, in that connection, utilizes a system to determine wnen and whether to hold certain types of information in confidence.
The application of that systen and the substance of that system constitutes Westinghouse policy and provides the rational basis required.
In determining whether information in a document or recort is proprietary, the following critaria and standards are utilized in Westinghouse.
Information is proprietary if any one of the following are met:
(a) The infor.sation reveals the distinguishing aspects of a process (or component, structure, tool, metnod, etc.)
where prevention of its use by any of Westinghouse's competitors wit:-out license from Westinghouse ~ constitutes a competitive economic advantage over other companies.
(b)
It consists of supporting data, including test data, relative to a process (or component, structure, t >ol, method, etc.), the application of which data secures a competitive economic advantage, e.g., by optimization or improved marketabiiity.
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CAW-79-40
. (c)
Its use by a competitor would reduce his expenditure of resources or improve his competitive position in the design, manufacture, shipment, installation, assurance of quality, or licensing of a similar product.
-(d)
It reveals cost or price information, production capaci-ties, budget levels, or commercial strategies of Westing-house, its customers or suppliers.
(e)
It reveals aspects of past, present, or future Westing-house or customer funded development plans and programs of potential commercial value to Westinghouse.
(f)
It contains patentable ideas, for which patent protection may be desirable.
(g)
It is not the property of Westinghouse, but must be treated as proprietary by Wastingnouse according to agreements with the owner.
(iii) The information is being transmitted to the Commission in con-fidence and, under the provisions of ICCFR Section 2.790, it is to be received in confidence by the Commission.
(iv) The information is not available' in public sources to the best of our knowledge and belief.
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CAW-79-40
. (v) The proprietary information sought to be withheld in this sub-mittal are the responses to NRC questions related to guide tube thimble wear directed to applicants for operating licenses for Diablo Canyon Units 1 and 2, McGuire Units 1 and 2, North Anna Unit 2, Salem Unit 2, and Sequcyah Units 1 and 2.
Public disclosure of this information is likely to cause sub-stantial harm to the competitive position of Westinghouse as it would reveal the basis 6f the Westinghouse fuel assemoly design for the designated plants and similar plants, wnicn is recognized by the Staff to be of competitive value and oecause of the large amount 'f effort and money expended by Westing-house in development of this design.
This information is valuable to Westinghouse because.
(a)
Information resulting from this design gives Westingnouse a competitive advantage over its competitors.
It is, therefore, withheld from disclosure to protect the Uesting-house competitive position.
(b)
It is information which is marketab?' in many ways.
The extent to which such information is available to competi-tors diminishes the Westinghouse ability to sell products and services involving the use of the information.
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CAW-79-40
. (c) Use by our competitor would put Westinghouse at a com-petitive disadvantage by reducing his expenditure of resources at our expense.
(d) Each component of proprietary information pertir ent to a particular competitive advantage is potentially as valuable as the total competitive advantage.
If com-petitors acquire components of proprietary information, any one component may be the key to the entire puzzle, thereby depriving Westinghouse of a competitive advantage.
This information enables Westinghouse to:
(a) Justify the design basis for the fuel (b) Assist its customers to obtain licenses (c) fleet warranties Further, this information has substantial commercial value
~
as follows:
(a) Westinghouse sells the use of the information to its customers for purposes of meeting NRC requirements for licensing documenta tion.
(b) Westinghouse uses the information to perform and justify analyses which are sold to customers.
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CAW-79-40,.
(c) Westinghouse uses the information to sell nuclear fuel and related services to its customers.
Public disclosure of this information is likely to cause substan-tial harm to the competitive position of Westinghouse in selling nuclear fuel and related services.
Competitors could obtain the e,quivalent information, with difficulty, by investing similar sums of money and provided they had the appropriate resources available and the requisite experience.
Further the deponent sayeth not.
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GUIDE THIMBLE TUBE WEAR QUESTIONS RESPONSE TO L. S. RUBENSTEIN'S LETTER TO H. G. PARRIS DATED SEPTEMBER 14, 1979 NONPROPRIETARY VERSION t422
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Please provide the basis and derivation of the guide thimble wear m In particular, explain assumption 4 and the eq in Reference 1.
under assumption 7.
ferential wear?
RESP 0ilSE 1 Consider the interface between the guide tube, the control rod assemb Each absorber rodlet is guided in the upper fuel assembly, shown in Figure 1. internals by the guide tube, and in the tube.
The rodlet is clamped against the guide tube by the coolant press The length of the clamped portion depends on the coolant pressureThe and the alignment of the guide tube with the fuel assembly.
in Figure 2.
is pinned in the fuel assembly guide thimble tube.
As illustrated in Figure 2, a certain portion of the absorber rodlet, with
[e unsupported. As sho n in Figure 3,[-
,] The correspor.dir.:
[e
."L",
i.e vibration of the c'ylindrical rcdlet results in the oscillation of tha p tip, with a maximu:n angle of rotation C.
of this engle, as shown in Figure 4.
The maximum angle of rotation e is [1, 2]
d1o V2 6 6 ;u 6
e = 5.72 Q 4(x ) f where:
Q is the magnification factor
$' is the fundamental clamped-pinned mode shape is the abscissa of the dynamic lift force
,xF f is the fraction of F( at rod frequency F is the dynamic lift force t
L is the unsupported length is the rodlet dynamic stiffness K
The total travel of the rodlet tip, in contact with the guide thim surface, is:
2 o D, f T
=
n Where:
D,is the rodlet diameter f is the rodlet natural frequency t_ is the total vibration time; this is the total time during whiclr n
the rodlet is parked in a given axial position.
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Finally, the wear volume associated with this travel is V=
F.T.W.
is the lateral contact force between the rodlet tip and the thimble F
tube W is the wear coefficient In order to convert the wear volume into a wear depth, censider a typicci wear scar the observations of wear scar geometries, the wear depth
'.-f CU D
in Figure 5; from be detemined from W.dL
[a,c]
[
]
and V
=
A where:
il is the wear area A
L is the axial length of t!ie waar scar g
Figure 6 represents a wear scer as measured in a thir..bic t'.de and confirn-ti.c illustraticn of Figure 5.
The above equatiens relate the ma:imca local wear depth i'g to the para.cters :ffc.t-ing the rodlet vibration: geometries, flow, stiffness and tne wear phenomenen:
contact force, time, wear coefficient.
References _:
Y. C. Fung " Fluctuating lift and drag acting on a cylinder in a flow at supercritical R ynolds numbers", Jnl. aerospace science, vol. 27, fio. 11,
[1]
November, 1960.
W. T. Thomson, " Vibration theory and applications",1955, Prentice-hall,
[2]
eg.10.7-14 Appendix C.
o m+o em ry 3 mM J Xo =
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1 gue_s_ tion 2_
Using the guide thimble wear model, Westinghouse has predicted maximum and str ess intensity limits for worn guide thimbic walls in two fuel assembly handling load.
These calculated values designs, which were subjected to a 63 We note that the stress intensity limits are listed in Table 4.1 of Reference 1.
increase as a function of time for both fuel assembly designs and that always rcmain greater than the maximum stresses, which increase a From the supporting discussion prcceeding Table 4.1, it is not c if the stress intensity limits are time dependent.the noted incre worn away.
il toughness, associated with irradiation hardening.
5 it is contrary to tne previous Westinghouse position in Reference 2 Please clarify whether or not Uestinghouse has taken credit f Show that the criteria adopted rcpresents the more of Reference 1.
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irradiation strengthening.
conservative approach.
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RESP 0:!SE 2_
The accelerations and resulting loads applied to a fuel assembly 1, 2, 3 cnd 4 operations are non-cperational loads, as opposed to conditions induced loads.
ln analyzing the non-oparational loads, credit is taken for the inc yield and ultimate strength.with irradiation.
On the other hand, the fracture analysis is perforr:cd to addres As you mention, the material toughness, characterizcf "
f irrt:J; tic the criticcl stress intensity factor, sheuld Le a decreasing fun
.'ir material toughness.
is nd the maximum experimental value from tests on 40? ppni hydrogtn c and therefore of time.
20 n/cm, E > 1MW. [1]
d zircaloy 2 after irradiation to 2.5 x 10 lic:
This minimum value, applicable to 250 week results, has conse to 25 week resul ts in Table 4.1 of our report !!S-T".A-2102.
' '),willit in a In additien, the postulated crack in a thimble tut.e, [
lhc 25,000 state of plane.. stress and thereby will develop h i
te_t result represents a lower bound toughness.
sider' In summary, credit is taken for irradiation hardening when Sy a it conser The minimum frac ture toughnc.
i d from for non-operational loading conditions.
va.ti,vely used, regardless of irradiation; this experimental v ditions.
~.
planc strain tests, is conservatively applied to plane stress con This load is significantly handling load has been assumed.
i sra tico higher than the actual load actually imposed In addition, a 69 l t;
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in load transfer when yielding is reached. represents a Journa'l.
Reference _
R. G. Hoagland and R. G. Rowe, " Fracture of irradiated Zi of Nuclear Hatorials 20 (19G9), p.179 - 195.
1.
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Guide thimble wear data, which were taken from Point Beach Units 1 and 2 sp fuel, are discussed, listed, and plotted in Section 2.3, Tabic 2 1,.and F Please confirm that the time units in Section 2.3 Should not the units respectively, of Reference 1.and Table 2.1 are in error and make correct be days instead of hours?
.RE_SP0t!SE 3 The units should be in error.
.The time units in Section 2.3 and Tai n 2.1 are days instead of hours.
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. 00CSTIOrt 4 Submitted Westinghouse infonnation does not explain.why the guide thiubic uear rnodel, which was developed from measurements taken on two 2-loop plants wi 14 x 14 fuel assemblies, is applicable to wear predictions Therefore, please explain designs.
and " core-position" dependence in the observed wear.
how the model accounts for wear differences and provide supp are justified, the supporting data can be provided in a confir Westinghouse design variations.
a schedule for its implementation, and state your commit NRC approval of the model.
considering the availability of irradiated assemblics in all Westingho confirmatory program.
RESP 0tlSE 4 The guide thimoie wear results obtained from f
a possible core 1ccation effect on the wear den, th.the re The ani.ysi ofthedatashowsf
)$
aao
. u no lic o
The plant specific effect results from differences in n'echanica These differences are accounted for in the. ea The var'.ous parsreters affecting the we:r dgti' 'sthe re ir.*. rr.:.1 characteris tics.
in response to Question 1.
change as the fucl assembly design, che control rod assembly,icted fo This explains th' different results pred d to sheath wear depth as compared to 17 x 17, anc split tube guidance as com or the flow change.
guidance.
l trert-Report its-TMA-2102 and the response to qu.:stion 1 pre t on tha ment of design variables such as geometries and flow, and th
. wear predictions.
h ws ade-The safety analysis, performed according to standard SAR r quate safety margins even in the extreme case i
2 and exten-
.sive trouble free experience provides substant a j
wear is not a safety concern in Uestinghouse plants.
In response to the NRC request, we are planning to meet w i
to providu, to detennine whether some on-site examination should be imp Based on the meet l
additional confirmatory information relative to thimble wear.
i ani-firm the nation, such as boroscope or scme equivalent technique, inte 12, 1979, tion with of October j ~-
absence of evidence of holes in fuei guide tubes resul RCCAs in the " parked" position. specifics of the program w be done by January, 1980.
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QUE5TI0t! 5_
In Reference 3, Westinghouse stated that the effc;t of hydrogen content on th mechanical properties of Zircaloy is discussed in L' CAP-9179 (Reference 4 He have reviewed that topical report and found no information on this issue.
Please provide your evaluation of how this consideration analysis.
Zircaloy as a function of the accumulative waar.
uptake of th.:
RESPONSE 5_
Hydrogen measurements on a thimble tube exposed in L'EP Point Be
]
[
one cycle were [
].
At one location in a bulce
{
Maximum pre-irradiation hydrogen content was [ joint t l
]
I
- ].
].
[,3 -
compared to the maximum measured value of [
I e, e og ests were At the t!estinghouse Research Laboratorics in Pittsburn I.-
i d ;rnm e,;
o Zircaloy-4 tubing, r These tests were conducted fcr four @7."E!
s n ~I
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of 304 stainless stbel.
6.1 thra' containing 1500 ppu b0ren and naintained'at a PH of N 9 Y
'h* fee'? 3 The measured hydrcacn content in' the water m s '#2 "3
'C #
of this test showcil that [ '
3-Earlier investigations into the effects of hydride plEtelets on the fract i
R:iled plate r.aterial, of reactor grade Zircaloy-2 (1.44:,
092:. Co,.U Y d
ica Nu) were additionally cold worked by roiling to levels of 0, 20 and in thickness and annsaled at 750 C for one hour.
(grain size of.035 to 0.40 en) were charged with hydeccen to Metallographic examination revealed the fo 2
400 pp.1 at 460 C.
/in. was.
and 400 ppa concentraticn level, a minimum toughness of X)c hydride dis tribution.
obtained between 0 - 20 C. increased, and no sub-critical cracking wa
] in the Therefore, [
The critical s. tress intensity factor, 25 Ksi /i_n.
for safety analysis of thiuble Hestinghour e to llRC response.
i t 9 sed in Table 4.1 of the analysis was appropr a e wear.
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QUESTI0tl 6 When Eddy current testing was conducted on worn geide thimble tub Point Beach Units, did the presence of zirconium hydrides affect th
?
How sensitive is the interpretation of cddy current signals to hydride p How is this effect taken into account?
RESPOUSE 6_
Eddy current measurements that were taken at the Point Ecach
]. [c Zirconiu'a 4.
The effect of these components is to increase the resistivity of the
[-
[.
[:
[
]
The wear depth was obtained as the difference between the signa
[
['
{
zonc minus the signal in the worn zone.
[
).
The worn zene being [This results in cn apparent thimble tube thirin i].
the worn section.
i No attent has been rad to include this effect in the da to its conservative nature.
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OUiSTIC:: 7 References 1, 3, and 5 do not address the consequences of hole formation Marcover, it is not clear from the submitted infon::ation guide thimbic tubes.if Westinghouse (1) has observed holes during insp tubes that were exac:ined in the Point l'each spent fuel, or (2) has p the guide thimble wear n:odel) hole formation to occu. during proje Also, if holcs h6ve been observed or are anticipated,i provida a discussion on the impact of such hoics nn guide thimble time. Please clarify.
This discussion should control red motion, and thencal-hydraulic perfon:unce.
also account for ficw-induced vibratien resulting in crack propagation This possibly fatigue fracture in locally thinned areas of the thimble wal i
discussion should address the integrity of the thimble tubes during the fuel core residence time; both during periods of wear (under RCCA) and assemblics are not under RCCAs.
RESP 0:!S" 7_
l tubes Westinghouse has not observed holes during inspection of the 4 that were cxamined in the Point E2ach spent fuel.
f cur The prcdictions of the guide thimbic wear r,sdel are presented i
[
l report I:5-TO-2102. They rcpresent a [
].
At [
l
].
All tne curves are.[
].
[
1 TD Th
[
D ' ND M A hm
-].
n3 in The flow induced vibration of the fuel cssembly will resu the guide thicule tubes.the maximum stresses are originated frca the [
The analysis of the vibration of a worn-through thimble tub of vibration [I
].
stress, at the wear scar, is [] vibration amplitude was con the peal; to peai:
A[
curve shown in Figarc 7.
d The The thermal hydraulic impact of t worn-through thimble tube wa i
tube, un.
increcsc in core bypass flow, which results from a hole in the thim
] would have to be worn'thrcugh in calculated to bc [
At least [
].
order to increase the core bypass flow by [] this effect in insignificant.
absorber rodlet bottem end plug cone.
The worn cross section is located above there, does not jeopardize the moves.; cut of which guides the rodlet and, the.
control rod assembly.
t The impact of such a hole on guide tube integrity is provided i NS-Tt1A-2102.
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QUEST 10il B_
During the review of t! CAP-9179 (P.cforence 6), the staff questioned the
)!cstinghouse value for the ultiraate tensile strcnqth of Zircaley co:nponents.
The subsequent !!estinghouse response (Reference 2) stated that the ultimat tensile strength of Zircaloy was not_ used in the design analyses of present However, the analysis contained in Reference 1 uses Therefore, please subi^ for fuel assembly designs.
the ultimate strength as a limiting variable. review the 1:estingho Zircaloy.
D]*l0a M M@ '
3 YlE 'titL RESP 0:!SE 8 Unirradiated values for.25 yield strength and ultimate strength used were lower bound values as indicated below:
]
[a Yic1d Strength
[
0 < T*F < 603*F
]
[a Ultimate Strength
[
0 < T*F < 603 F 1rradiated valuu of.25 yield strength used were lower bound valt.;;s indicat below:
3
[,
iteldStrength
[
O < T*f < 600 F nyt > 6x1020 (;, )
Because of the limited uniform clongation present in irradiated annealed Zirc I
(
the [.
~
3 The values for ultimate strength of Zircalcy-4 are used for failure analysis to Origm determine both failure mode and margin available for particular con.ponents.
design and analysis is based on the yield strength for Zircaloy-4.
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QUESTIOD 9 S_etion 4.1 of Reference 1 states that the stress intensity factors a This is as a function of time for 14x14 and 17x17 fuel assemblics in Figure 5.
Please provide such a figure or amend Figure 5 as necessary.
not true.
h, i
3 RESP 01:5E 9 The stress intensity factors are plotted as a function of time for 147 of our report I S-T:%-210..
17x17 fuci assemblics in Figure 6 0
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pursno:t 10 ironn wear Per item 4, Section 4.0 of Reference 1, your analyses arb ba lting Compare your results with analysis that considers non-unifonn s in all thimble tubes.
in a shif t of the neutral axis.
stress and bending stresses.
iformly in all RESP 0 :SE 10_
Assumption 4 of Section 4.0 states that wecr is assured t d to for tion is the sam:
occur in a thimble tube under a split tube, or shecth, loca thimble tubes.
fuel assembly.
all thimbic tubes under a split tubo, or sheath, in this m fuel Point Cecch me0surecants short wear results that vary, within the The wear model presented in !;S-T;'A-assembly, from thiuhle to thimble.
in a given fu 1 does not take credit for this observation: applied to all th iru-local assembly.
i As discussed in th; response to Question 1, the ecdel does pre hif t of tha neutrcl wear, and cur analyses da ta::c into cor.sideratica the s axis and the resultirg cirect and bending stresses, w
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QUESTION 11_
For Condition 1 and 2 load analyses of Reference 1, a skcu f Clarify hcw the ske.t that accounts for the uneven axial load distribui. ion.
factor is related to both gccccetric changes (resulting from une How does the skew factor impact the load analyscs?
assenhly misalignment.
RESP 0 HSE 11 During fuel assembly mechanical testing, strain
[3 The taeasure:nents showed tiiat,[
(;
in the fuel assenbly.
b lf l.0 all
.] It was conservatively assumed thcIcGd as the ti:2 thir.61e tubes under a split tube lccatior, have the sar? Sir.ilarly, all t:.. le with the raxin.ua load, in a split tu:;e location. tubes unda
.."A the
[
In addition,1
[
maximum load en a sheath locaticr..
di: v : n
] This is due to the fact th t *.he pr :
The shc.t factors um c;rr e,.
the loads over thintles and fuel rods.
i r l ' D., s.ere t the top, pan although 'the stress analysis is done cnc sp3r,This te Wear sc r is located.
therefore, the load on the thimbles.
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QUEST 10ii12
- Ilouever, The equation for tha wear voittne 'in Reference 1 appears linear with tir2 lting correlation in Figuit:s 5 and 6, trear depth is plotted versus time, and the res appears to be non-linear.
related.
RESP 0 :SE 12 The nc:i-linearity of the 1: car depth versus tic,e relationship is discus:.e Response to Question 1.
It results from[
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in Reference 1, it is stated O'JESTION 13 For Condition 3 and 4 load analyses, described are based on generic st.resslcul b
that the stresses in a worn guide thimbic tu e Please reference uitere these generic stress cagui d It is also stated that the stresses in the unwo due to inc for the reduction of the tube cross-3 calculations.
found.
This would indicate credit for a locd redistr 3 cnc 4 icad are increased to account guide thinble tubes. Describe the state of stress in the worn gu wear scar.
uneven ucar affects the load-bearing character analyses?
himble tubes tras based :n[
RESP 0 HSE 13 The Conditien 3 and 4 load analysis fer the worn t alues: [
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generic seismic plus LOCA event thit:. ale stress v), fror.
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i are calculated using finite elements core cod s as trcsses in cn The stresses calculated in WCAP 8236 Adde The exis tcr.ce of a wear sctr an hift are taken into accc >
unworn guide thieble tube.
tube cross-section reduction ar.d neutral axis sFor a given distritutien.
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ESTIO!! 14_
Discuss the potential for guide thimble wear in fuel assemblics vith core components other than control rod asser.blics.
RESP 03SE 14 thimble plugs, Core co:"ponents other than the control rod assemblics are:Both the bur burnable poisons, and sources.
are "long" rodlets that are inserted de.!n to the dashpot while theT thimble plug is a short rodlet. fuel assembly, rest on the top nozzle
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J This has been confirned by the cSser cati 5
r'e 31y D57, which hacJ a b ar:b'e p?rforr.ed en point Beach Unit 2 fuel assepoison asser.bly
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