An assessment or martensitic steels for low activation status

Journal of NuclearMaterials122 & 123 (i984) 777-782 No&Holland, Amsterdam

AN ASSESSMENT Oi I-?XRTEI:SITIC STEELS FOR LOW ACTIVATION STATUS

Thomas LECHTENBERG* GA Technologies,

P. 0.

Inc.,

Box 85608,

San Diego,

Cal lfornla

92136

An assessment of 12$Cr-martens1 tic steels has shown they may meet the requl rements for surf ace The guldellnes for maxlmum allowable residual waste disposal and can be melted and f abrl cated. impurity levels were calculated and must be adhered to and will impact the design philosophy for A deslgn equatfon has been wrltten for allowable amounts of fmpurltles any alloy composition. such that the producer and alloy design team can trade-off certain strengthening addltfons for lmpur I ti es. Introduce unacceptabl e I evel s of others when those pure-element alloy addftions Currently, the levels of Impurities for several dffferent lots of starting material are belng reviewed, and lmpllcatlons to alloy coinpositions assessed.

1,

require

INTRODUCTION The

Deve I opment

Alloy

Performance 9-12

Cr

flrst

task

class

wall/

Is of

the

materlals

In

the

mater

I al s”‘.

ADIP

program

single probable goals

can

on physical

power

reactor

the

primery of the

%Ince

at

shown

to

special removal

mater

IaI

authors

rlsk

specie gratefully

results be

quickly

resultlng an

fran

support

0022-3 115/84/$03.00 0 Elsevier Science Publishers B.V. (North-Holland Physics Publishing Division)

they

could

The

relative

of

the

costs

safety

of

the

surface

are

cost

easl ly,

at three the

of

$200-600

as

classes

of

Impurities

of

other Fusfon

decay

such

that waste.

of

surface

cannot packaging

they cubic

have foot

surface

for

waste,

al ternatfve, Energy

all few

surface

for

per

major

that

dlsposal

but

of

While

enough

monitoring,

only

of

advantages

geologic

waste

Is a relatively

weak

that

geologic

because

levels

I

Al I

deep,

disposal.

dfsposed

without

Office

for

of al

meet1 ng

such

radionuclldes

or

be

not

actfvate

it

are

disposal.

require

and

(l&R)

classes

whl ch

others

will

activate,

vs.

for

al I

qual Ify

daughter

estimated

will the

the

reactor

geologic

surface

enough

burylng

the

DE-AT03-76ET51011.

the

four

C,

many generations

will

have

and

and

elements

est fmated

for

B

would

for

disposal

this:

release

accident

acknowledge

to

activated (2)

service,

during

a f uslon

required the

for

high

tat lored

will

has

Ire

not and

constituent too

elements

of

of

malnten-

address

and

water

materials

wquld

disposal

with

and materials

results

I fght

A,

utll

disposal,

no

that

f ran

of

after

they

the

I ong-term

alloys

costs

remote

lOCFR61,

disposal, must

conventlonal

the

material

will

storage

surface

fcatlons.”

alloys

safeguards

safety

activated

time

satisfy

neutrons

three

wastes

of

this

the

Cl asses

these

reactor

properties

are

and

I mater-

goals

Increased

concerns

guldeline,

waste.

consider-

. . . the

appl

waste

reccm-

fuslon

structural

There

(1)

potential

of

conventlonal

the

has

These

management

Currently,

actlvatlon

and

developing

and

with all

I vate3.

*The

be

I nteractlon

machlne

of

state2:

focused

fusion The

act

the

f usf on env lronment are

cause

one of

Furthermore,

mechanl cal for

machfnes

development

alloy

low

and (3) tncorporating

Issues.

the

DOE has

1vat I on of structura

remaln

In

for

and

equf pment.

waste

In

Recently by

ante

the

appllcatlons

constituted

fusion “Act

should

for

requirements

mended that,

evaluating

blankets.

Panel

assessed

ations

steels

breeding

LOW Actfvatlon

lal

currently

mttfgatfon,

developing

Irradiation

for

under

be and been any whl le

geologic contract

disposal, per

I lkely

will

cubic The

of

the

the

release

of

most

to

fol lowing f fres,

I lthl

or

through

urn or

other

materfal

material.

Unlverslty

oxide

of

less

unless

that

the

Is

point

of

concern

and

point

at

thls the

A

material

temperatures

blanket

the

objective HT-9,

low

acttvatlon

Activation would of

of

Panel

due

to

its a

for

a

I

this are

the

producing

was to qual lfylng

deflned

In

low

was assessed

the

actlvatlon

I

assess for

the

Low

three

goals

and contact feaslbllity

alloys

by lnteractlon

wlth

of

of

thls

two

producers

model for

perform

steels

thls

recently Th Is

study

Is

was

reactor

represents

studled

fusion

rltlc In

steel. this

the

study

the

selected one of

reactors

the

MARS because

the

most

whose

The b I anket is

blanket

June

compared

to

In

those

MARS.

conf

blanket

to

95s Fe 1422+51

952 Fe 1422t5f "20

26.24 cm 7;;7&Lgbt7.1$

Hz0

HT-9 "t-9

1,s.z cm 1.078 N/A

1.,333 1.37

1.374 86.16 13.39 0.43

transport

obtain

but Ion of

code,

the

the

group on the

neutron

Is

and

B4C,

i guratlon of

ANISN,

DLC-37

flux

The

the

analysis

a

multlgroup

cross

25

were

employed using

calculation

their

Into

Then,

dlstrlbutlon

elements weight

dls-

blanket trans-

structures

calculation

and

the

group

I I brary8,

chemical

energy

In

ordfnates

col I apsed

calculation.

radioactlvlty

used

and

was per-

and

f I ux

The discrete

radloactivlty

fer-

spatial

and 21 gamma-ray

the

MARS

calcuiatlon

neutron

I lbrary,

transport

extenslvefy

1982 verslon

Jl;i ~P!Hl51

90

_-

The neutron

projec+.

blanket

f-t.USta)

90 28.24 73.72 LIPb+'I.lj HT-9 58.96 cm a52 LIPb+lS% HT-9

91.84 a.2

sectlon

chosen

HT-9/LI17Pb83

for

The

shown

(a)A 41 cm shield conposed of layers cf Fe 1422, Pb. cooled by rater "(1s Included lo the neutronlcs calculetlon.

port

calculations reactor/blanket

The fusion

developed blanket

activation

a specific

was selected.

are

0.7297

and ref I ector.

to

ferritlc

energy

f I uxes.

115.2 cm

s ~~~~~~ Aeftectw Shlsld

formed

al lays.

In order

the

type

ANALYTICAL

for

also

28 a

Total Blanket and reflector thickness Trltlwn breeding rstlo Pb (n.2111 Blanket energy multlpil~ti~n

trl 2.

group

was

structured

obtain

This Study

s 61.1 Concentratlo"

qua1 If icatlon

dlsposal,

Furthermore

ANISN7

steel to

calculation

hlgh

Its

Thls

waste

also

calculation

code

ferrltic design

and for

transport

dependent

frcmn

reported

volatile

work

report.

surface

those

as

probably

unoxldlzed

of

1t meet two of the

maintenance.

of

to

status

require

safety,

this

wel I

as an alloying

formation

relative

cm.

ferritlc-structured

ordinates

blanket

posl tlon

Blanket

The

115.2

equally

and

of

a total

resulting

appl les

design

neutron

oxI de5.

alloy,

of

radloactlvlty

class

discrete

performed

Table

design.

has

blankets.

results a

and

thickness the

design

whole

detailed

uslng

and

of

July

the

MARS blanket design

reflector

blanket

Lll7Pb83

forms

the

Manganese

a major

meltlng

material

Is voiatlie

Both struc-

the

to

of own

the

I ikely the

melting

pressure

the

Wlsconsln blanket

and

Ll17Pb83

Its

temperature

blanket

to

breeder-material

has

of

a thick

from

Is

I ization

decay4.

material.

element

off-site

which

is

The Implication

mechani sm for

radloactlve

the

I Ize

below

of

deflned.

volatl

The higher

a material.

structural

well

material

ral se the

volatl

less

important

due to

scenarios

vapor

$200,000

I oss of cool ant to a structure

by

self-heating

surface

to

imp1 fcations

be

activated

well

is

activated

cons1 dsred

will

safety

actlvatlon

highly

closer

It

issue

Currently,

tural

be

foot.

materials

of

/An assessment of martensitic steels

T. Lechtmberg

778

as

an

neutron based for

the

input

code,

the group

to

the

DKRg

the

was performed. selected fractions

for In

the poten-

T. Lechtenberg

tlal

fusion

listed

In

topic

blanket Table

sectlon

data

tanta

exists

due to

could

not

the

reaction

not

at

be

maximum niobium al loy,

since

activity

in

for

Included

may

al I

of

this

time.

the

g3Nb

the

level

low

isotopes

a mixture an

the

of

isotope

concentration

This

In

the

quite

to

based

such

reduced the

of lmpurltles

for class "A" waste

MaxImum Concentration appm. IO Yr.

Danlnant Nuclld

1,220 2,550 200 70 190

Co 60 Fe 55 NI 63 MO 93 Nb 93m v 49 Co 45 w 161 Co 60 Ni 63 c 14 Hn 54 Al 26 Co 60 zr 93 Nb 92 Nb 94 Be 10

:I w CU N Hn : Nb

s

achieve

mlnlmum

to

as

low

certain

and

all

transmute

Ides must

activation conventional alloying

and molybdenum

levels

that

of

HT-91,

as nickel

matrix

be

to

in

must

be

Impurities

In

unacceptable

reduced

proposed

lOCFR61

In

waste.

For

fran

MO

to

cannot

to

strl

ngent

regulation

waste

II

concentrations

NI

waste

Concentration

on$ modif lcations

(such

elements

g4Nb

are

order

alloys

I lmltatlons

Element

the

ratios

regulation

Maximum Allowable

materials

ngent.

In HT-9 to qualify

In

In the

radium.

sum of

RESULTS

radionucl

MaxImum elemental

than

the

one.

3.1.

g4Nb

potential

on

3.

the

speclfylng

waste

TMLE

other

isotopes,

concentration

exceed

elementa

(n,y)

In the

requirements

of

Also,

for

concentration

ele-

e.g.,

library.

important

alpha-sanlttlng For

119

steels

I I brary,

these

In the

of martensitic

iso-

cross-

some el events,

presence

data

is

for

actlvatlon

DKR cross-section

be reported

cross-section reactlon

for

are

occurrlng

assumed

no neutron

In the

I urn,

activity

strl

were

Because

alloys

Naturally

II.

abundances

ments.

structural

/An assessment

of

HT-9

would wt-%

A Ilst

(HT-9)

material

the

proposed

fol lowlng

must

I Ike

than

380

appm,

1O22 atoms/mole

estimated

given

of

impurities

not

exceed

or and

be 55.2

a 12Cr-1Mo

Table

II.

The

introduced

the

atlon

to In

in

“lmpurltyk

Calcu-

wal I material

radlonuclldes

regul

l’Ak

products

maximum allowable

less

weight

should

the

be

Is

class

and N163.

the

on 8 x

of

amounts

alloying by

to

atcmlc

gms).

Fe55,

that

(based

for

transmutation

in a first

have

alloy

qual Ify

~060,

shown

nickel

0.040

total

5;: 60.000 270,000 63,000 13,000 260.000 0.1 49,000

are

have

amount

to

examp I e,

nfckel

lations

an

5.250

order

amount

lOCFR61, equation

by

dictated e.g.

that

requirement

be met:

MaXImum ConCentrations calculated as If each were the only InpurIfy In the matsrlal

l

c Maximum mined for

fran a

the

For

I lnes

the for

Isotopes value

beta

radiation, was

used

signlflcant for

for

U-235

the

In the

value

for

radiation, Cl/cm3)

x~nl/Kj’l

i

was

where

gul de-

Cl/cm31 wlth

beta-emitting

gamma (0.4

classiflca-

(0.4

isotopes

deter-

10CF6110

waste I isted

g0Sr

for

were

regulation

not

emitting

no gana

value

proposed segregated

uCl/cm3) wlth

concentrations

low-level

t/on.

used

Isotope

Xl

Is

residual

the

atorn

element

1.

parts q

per

1 Is

mll I ion

the

was

actlvlty,

and

Ilttle

or

actlvlty

according

to

10CFR61.

This

Cs-137

(10

fraction

of

allowable

radioactivity

says

the

Ki

is

the

isotopes

due

and

the

fraction

of

that

element

used

for

summed over

al I

expected

to

any

Impurity

allowable

element

times (In

appm)

lmpur II-y

of

specific radioequatlon

the Is

atomic to

elements,

be

780

T. Lechtenberg f An assessment o~~~rtells~tic steels

TABLE III

E I ement Ni

Co60 Fe55 N163 Mo92 Nb93m Co60 Ni63 Cl4 Co60 Zr93 Nb92 Nb94 Mn54 Al26 Bet 0

MO CU

k Nb

Nn

Al B %atcuiations and

that

These

summation

data

Thus,

are

can

be

specie

be

less

in Table

III.

written

that

by

Co.

But

two

orders

as

canpared

those

the

For

n/K

of

factor

radionucl

Ides to

Is

that

In

Included.

SO,

Co60

(one

or

on I y

So,

to

example,

and

Cu and Co

while

for

N

in

the

would

for

Cl ass

X~+Z.45~10-~ X&,+10

XAl+1.6~10-~

Class

6,

be A

the

equation

.8x10-3

3.2

The

Feaslbi

of

1

should

canposition

if

these

materials

was determined

to as

from

be -

reduce

must

which

residuals

in

increase

the

sary

between

more

chromium

maintain

Is

the

to

met,

available

virgin content

because,

molybdenum

content

to

It

as

adding in

niobium

content

So,

order

to

further

deslrable

other

which

to

a trade-off tungsten

fran

The

compensate.

is made may have

Nb

to such

tungsten such

for

strengtheners

be added

but

speclficatlons

important

other

be

residual

be

residuals

the

possible,

as tungsten ore

that

the

that

are

with

their

This

activation control

probably

and

and

example, low

could

analyzed

I ned.

4.

1

may

above

the

may be necesand,

for

example,

mlnlmize

impurity

additions

mechanlcal

yet

also

propertles.

DISCUSSION Other

production simliar

qual Ity

ccmposltions

be

determ

Low Activation

two

It

materials

of at

concerning

careful

required

speclflc

tallorlng

staff

problem

XNb <

Producing

that

Stee I s

of

>*

the

contamination

X~tl.22~lO‘~X~u

XN+l .27x10m6 X&l0

I lty

XCu

would

+1.6x10-7XMn+l.91X10-4~A,

on the

speclficatlons.

XRb

XMn (

2.57~10’4Xh~t3.25~10’4 ,Xt

(

1”

necessary

as

be major

included

an approximation

X~%2xlO’~

+8.44x10-3

(

5.14x10-3 1.43x20-2 5.2x10-3 1.9x10-4 2.457x10-2 l.8XlO’3 1.2x10-5 3x10-6 (3x20-6)

and

amounts IS

Cu,

low for

appear

XNitt.43~10’2

+1 .8x10s3

1.6x% 8.44x10’3

produced.

only

is -

5.14x10-3

steels

is

radio-

N ,

I ons.

are

this

the

very

lower)

activity

equation.

for

examp I e,

transmutat

N

8.17x10-4

35 10 10 7000 35 8 7000 10 (20) 0.20 7000 10

consulted

unity.

an emplricai

from

magnitude to

(n/K) Class A

7000

products

dcmlnate

transmutations

contributors

waste

than

accounting

would

levels.

activity produced

K

in Progress

must

shown

Regulation Requirements, Class A

5.72 2.74 0;28 0,143 0.052 1.35 0.86 0.0145 0.0844 3x20-5 3x20-5 0.20 0.117 0.0844 8.10’6

as a good approximation,

equation those

Speclf ic Activity,n (Cl/cm3/appm)

Dominant Radionuclldes

producers

of

and purity were

proposed

structural

materlalll,

of

solutions materials

to are

the

elements

that

or

(2)

use

the

waste (1) are of

disposal isotropic

used

in the

conventtonal

T. Lechterlberg

materials that

without

activate

Isotopic

certain to

control

tailoring

naturally

occurring molybdenum

I nteractl

by

ly.

Isotopic

such

which

ng w lth

radionucl

g5Mo to

has

the

during

g3Mo coul d,

therefore,

d I sadvantages

of

Industry

have

the

would

offending addition,

produced

heats

the

of

an

Al so,

done

and

tailoring

of

offending Two

a dual sitic

to

the

with

respect

phase

of I te

Silicon

shown

produce

may effect

alloy

which

radiation, phases,

body-centered therefore, In addition, martenslte

of

is

not

the fully

some ferrite.

effect

strength.

cubic inherently the act

and

in

to

number getter

(2) to

to of

of

in

of

the

sll

shift

is

in atcmlc have

be

icide

molybdenum

also

further

data may

embrittlement

smal I

pranotes

to

which be

a

carbides.

the

reduced

about

percent.

a

lmpurily suggests factor

of

in

ferrltic

s14.

REFERENCES

2.

wFusion Technology Development PI an Draf tw, Department of Energy, Off Ice of Fusion Energy, May 1983.

3.

Vogel sang, W., G. Kul cl nski, R. Lott, and T. Sung, wTransmutations, Radioactivll-y, and After-heat in a Deuterlum-Tritlum Tokamak Fusion React I on”, Nuclear IQ&IX&& 22 (1974) 379.

4.

HOI dren, J., wFuslon Energy in Its Fitness for the Long Term”, 2M (1978) 168.

5.

HOI dren, J., ItAspects of Safety for Fusion Mach1 nes”, presented at ANS meeting, 16 November 1983, Wash 1ngton, D. C.

6.

ME. Sawan, J In-Hua Huang, wNeutron Its Status of the MARS LfPb Blanket and Shield,w WIS-MARS-82-049, University of Wisconsin, 20 July 1982.

this

resist-

Context: w,

behavior.

ferrite,

structure,

resistant

large

and

properties

damage and swelling

irradiation

In

that

“Panel Report on Low Activation Materials for Fusion Appl icationsw, presented at DOE, 18 December 1982. (R. Conn, Ed. 1 In press.

marten-

corrosion,

martensite

nickel

and

precipitate

I izes

recent

the phase

1.

I ize

steel

While

on activation

4.

molyb-

stabi

temperature, of

steel

nickel

a decrease

would

contents

causing

the

the

elimination

to

phase

the

ance,

extent, (1)

a

also on

shift

levels

eliminating

are

should based

will

which stabi

be

M23C6 carbides

should

titanium

may

as molybdenum

martensitlc

molybdenum

and

affecting

amounts

amount

for

to the

isotopic

could

present,

contains

Both

in

steels

in the

has no adverse it

nl ng due

but

that

in

a lesser

if

carbides

amount

that

to

order

increase

tungsten

shou I d

al loys

martens

be very

controlled

to

which,

a shlf t

has must

scale

required

The exact

levels

and to

fully

for

martensltic In

strengthening

manner

same as

of

same canposition.

clear

influences

and,

strength

denum,

not

simi I ar

of

versus

fully

Tungsten a

also

the

time

adversely

HT-9. into

and

Proposed

differences

shift,

same atomic

for

I lze

alloying

steel

levels

been

the

Isotopes.

lZ%Cr-contai

In

the

large

the

major

molybdenum a

the

a

a

characteristics,

composition

HT-9.

entlre

because

phase

In the

stabi

incubation

attractive.

w I thout

separate

control

risky

GA Technologies

is

a

with

every

lored

lmpuri ty

It

on

elements

of

The

an to

qua1 ity

ly-tai

at

residual

smal I l*,

in

determining

alloy

produced.

more

this

field

g3mNb and

the

Therefore, is

counter

has

g4Mo and

that

swel I ing13.

added

processing

be created

be very

Isotopical

work the

is

to

and

a conventional

that

this

be

increasing

activation

unaccept-

cause

greatly

781

steels

strength

activate

respective-

isotopic

not

would

difficulty

between

the

radlonuclides

isotopes

element

to

would

dominant

For

occurring

g4Mo and g5Mo,

of martensitic

structure

certain

elements.

stable

g3mNb and g3Mo,

be removed

that

of

nine

tailoring

ides.

remove

neutrons

Ides

elements

radlonucl

to

isotopes

two of

able

led

means

example, isotopes,

alloying

/ An assessment

and

are are,

swellingl3. dislocations

vacancies,

thus

782

T. Lechtenberg

/An assessment of martensitic steels

7.

W.W. Engle, Jr., 'ANISN; A Multlgroup One-Dimensional Dlscrete Ordinates Transport Code With Anlstroplc Scattering," K-1693, Oak Ridge National Laboratory (1967).

11. Conn, R., Okula, K., and Johnson, A., t~Mlnlmlrlng Radioactivlty and Other Elemental Tallorlng of Features of Materials for Fusion Reactors", Nuclear m, 4L (1978) 389.

a.

D.M. Plaster, 8t al.., tQupIed 100 Group Neutron and 21 G-a-Ray Cross Section for EPR Calculations,tl ORNL-TM-4873, Oak Ridge National Laboratory (19355).

12. Memorandum, Battaglla, J., to Lechtenberg, T llRadloactivlty Calculations for Low memo Alloy Design", GA Al;Ivatlon JMB;MPMS;8202, September 28, 1982.

9.

T.Y. Sung and W.F. Vogelsang, "DKR: A RadIoactIvIty Calculation Code for Fusion Reactors," UWFDM-170. Nuclear Englneerlng Department, University od Wisconsin, Madlson, Wisconsin (1976).

13. Llttle, E., "Void Swelling In Irons and Ferrltlc Steels", J. Nuclear Materials, 87 (1979) P. 11.

10. Nuclear Regulatory Ccmmlsston, l'Licensina fo; Disposal o? RequIremet& Land Waste," RadIoactive lOCFR61. Federal Register, Vol. 46, No. 142. July 24. 1981.

14. Gelles, D., l'Mlcrostructural Examination of HT-9 Irradiated In the HFIR-CTR-32 for Development Alloy ExperImentI', Semlannual lrradlation Performance Progress Report, DDE/ER-0045/g, p. 161.