ML20090K386

Applicant Exhibit A-93,consisting of Technical Rept 5, Evaluation by Linear Elastic Fracture Mechanics of Radiation Damage to Pressure Vessel Steels

ML20090K386
Person / Time
Site:	Catawba
Issue date:	12/12/1983
From:	Mager T, Fabian Thomas WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP.
To:
References
A-093, A-93, NUDOCS 8405240190
Download: ML20090K386 (3)

Text

mv.

r .. . . . .

e

_ . . . -n - --

p ~

5 7.=ED 7:1  % ~

) .

t n

s1 # v 1'JiR 2 3 ga:

/ aa1:B%

1EcY3G ,/, $ .  !<

q'q p?

/ng.)Q,

i3 i

HEAVY SECTION STEEL TECHNOLOGY PROGRAM I! 1 g ,

TECHNICAL REPORT NO. 5 P

(NOVEMBER, 1969) h

EVALUATION BY LINEAR ELASTIC g

i FRACTURE MECHANICS OF RADIATI N DAMAGE TO 5 PRESSURE VESSEL STEELS

• 4

?

by $

T. R. Mager b p i j

F. O. Thomas

[$

i

.9 5

.i n

October 1969 "

Y f.

• Research sponsored by the U. S. Atomic Energy Commission under .

contract in part with the Union Carbide Corporation. [.

i h

/ / sy )y

\

APPROVED: /.

W. S. H 6 elton, Manager APPROVED; ff

'B. Keh i.

Plant Materials Engineering \

Project Engineer g

Fracture Mechanics Programs s t

k l

WESTINGHOUSE ELECTRIC CORPORATION g Nuclear Energy Systems .

PWR Systems Divfaion l P. O. Box 355 }i l Pittsburgh, Pennsylvania 15230 I

~

h 8405240190 831212 PDR ADOCK 05000 q L

% 0

4 , .

A

%} 4 '

< l ~

I F '-

s i

Because the microstructure and mechanical properties of the interior of the 12-inch-thick plate (1/4 and 1/2 thickness) were essentially the same and t

each locathca was isolated in a given capsule, the influence of the flux level i

can be evaluated. Capsule No. 5 contained specimens from the quarter thickness 'j t

location of the 12-inch-thick plate and was exposed to a fluence of approxi-

, mately 4 x 10 ' n/cm while Capsule No. 6 contained specimens from the center thickness and was expxed to a fluence of 1.3 x 101 ' n/cm . When the '

, 30 ft-lb transition temperatu're-shift and K values after irradiation are $

compared, it is evident that 1.3 x 10 ' n/c 1

does not saturate the material with regard to irradiScion damage. '

( The final objective of the program was to assess the influence of applied i tensile stress during irradiation on the fracture toughness of the various l j

pressure vessel materials. The data for the pre-stressed fracture mechanics

{

specimens are grouped together in Table 41: From Tables 40 and 41 it would7 I I

, t appear that an applied tensile stress of 26,700 psi during irradiation neither ,' E

. enhances nor reduces the radiation embrittlement sensitivity of the pressure  :

vessel steels studied. This a consistent with other investigators' data ( f based on Charpy V-notch specimen 4 subjected to an applied tensile stress during irradiaticn. The one exception in this investigation was the  !

European forging grade steel. This material exhibited a KIc "*1"* """ E "#

than expected and resulted in an invalid data point. However, if the plastic i t

zone size during the prestressing is taken into consideration, it can be con- i cluded that the apparent erroneous KIc ** * " * ' * " * " * * "#E*

• l plastic zone size at the crack tip during prestressing, rather than the in-l fluence of the applied stress during irradiation. ,

6. CONCLUSIONS ,

I g 1. Weldment material of A 533, grade B, c1As's 1 steel produced by the j submerged arc process exibits a higher fracture toughness (KIc) at  !

a given temperature then base plate material of A. 533, grade B. I class 1 steel when evaluated prior to irradiation.

2. European 1.2 MLO7 forging grade steel, while exhibiting a somewhat lower resistance to fracture then the weldment material of A 533,

i l

l I

grade B, class 1 steel, exhibits a higher fracture toughness (Kk) at a given temperature than base plate material of A 533, grade B, I class 1 steel when evaluated prior to irradiation. I

}, 3. Weldment material of A 533, grade B, class 1 steel produced by the submerged are process was relatively sensitive to neutron exposure.

The 12-inch-thick plate (HSST Plate No.02) of A 533, grade B, '

I class 1 steel and the European 1.2 MD07 forging grade steel were <

l relatively insensitive to neutron exposure. The material from the 8 -inch-thick plate of A 533, grade B, class 1 steel fell in between f the two extremes of sensitivity.

4. After an exposure to a fluence of 1-5 x 10 19 2 n/cm , the shift in j the K Ic versus temperature curve was always less than 30 ft-lb  !

transition temperature shift. ~ ~

5. The material at the top and bottom surfaces of the 12-inch-thick j plate (HSST Plate No. 2) of A 533, grade B, class 1 steel was considerably tougher than the interior of the plate. It was con- j cluded that this phenomenon is due to the quench and prolonged  !

temper treatment that the two surfaces underwent during the quenchinz .f i

of the 12-inch-thick plate. -

• 4

6. ' An applied tensile stress during irradiation neither enhanced nor '

reduced the radiation embrittlement sensitivity of the pressure vessel steels studied. -

l I 7. EXAMPLE PROBLD{

ihe criterion now used by Westinghouse for safe operation of Reactor Pressure

[.s Vessels is that described by P,orse l, which is based on ductile-brittle transition temperature concepts. The transition temperature approach to -

design, limits the acceptable stresses in the vessel when the vessel tem-perature is below the design transition temperature (DTT). The design transition temperature is defined as NDTT +60*F and is considered to be the crack arrest temperature (CAT) f.: a stress equal to the yield stress of the material. The allowable hoop stress is temperature-dependent, and is defined

f h

6 9

/

rr

///

~ / l

/ /

l? . 'i'/\/!- /

g

_e  :

., I.\/ / 3

,ij N, /

e .

m

& /  :.: 6 O' 4 ,

/

}~

4

//jl, i

/f?

- '? y! l

!;lll !! /

?? ,l / 1

' '/ l ,,l cfD ej

U 4' 33 - 3

-/

f t

/

G ~Y

_,,l i

O

..