JOANNE WOODWARD says she's no longer an actress.

"I don't do films anymore," declares the 54-year-old Hol- lywood veteran, in a tone of voice usually reserved for menial housework. As in, "I don't do windows."

She also says she's not political, though her name has been linked with various liberal causes and she's back in Washington this week to chair the National Women's Conference to Prevent Nuclear War, which takes place today on Capitol Hill.

"I am not an activist," she says defensively, sounding very much like one. "I am often asked to do things and very often do them out of guilt or out of a need to make myself feel bettah. Feeling as though if you're very lucky, then you need to do something to pay for all the good luck. In this particular case, I don't think that applies."

What she is, says the silver-haired mother of three daughters (plus two stepdaughters, and a stepson who died in 1978, from Paul Newman's previous marriage), and the lover of books, ballet, theater, dance class, sewing, jogging, her wire-haired terrier Harry and just about everything else befitting a housewife from Westport, Conn. (except cooking), is a citizen.

A concerned citizen.

And as a citizen, she hates to give speeches, hates to be interviewed ("I always think there must be something else that both of us could be doing"), hates to get her "pic-tcha taken," bristles at any remotely frivolous inquiry (forget about What's It's Like to Be Married to Paul Newman for the Last 26 Years) but understands -- albeit grudgingly -- that talking to the press is one way to spread the message she so passionately espouses: nuclear disarmament.

"I'm hopeless, " she says. "I have a terrible time talking about myself. Because I get infinitely too emotional about it. I've gotta stop being so emotional because I think that's off-putting to a lot of people. People really just wanna hear the facts.

"I dunno. I look outside," she says quietly, "and wonder if a bomb's coming over. And when. It's either become active or crawl into a hole."

Citizen Woodward is sitting in her hotel room, knitting a red sweater ("for once for myself"), trying desperately to relax. She knits furiously, frowning as she drops a stitch, talking in the lilting, Tennesee Williams tones of her native Georgia, the voice that dripped celluloid honey in "The Three Faces of Eve" (which won her the Oscar as best actress in 1957), "The Long Hot Summer," "From the Terrace," "WUSA" and two films directed by her husband, "Rachel, Rachel" and "The Effect of Gamma Rays on Man-in-the-Moon Marigolds."

She hates her hotel room, it's making her claustrophobic. The photographer opens the window. "That's better," she sighs. "If I get too phobic, I jump out the window."

She is asked how much time she has to talk. "I don't know that I ever have enough to say. I can never fill an hour. I can't think of that much to say."

Her 19-year-old daughter Clea is on the phone. She is a student at American University. Woodward makes plans to meet her later for dinner. ("I didn't bring your bicycle because I couldn't get it in . . . I'm not going anywhere, unless I decide to change hotels, which I may very well . . . The dress code for the evening? Not wildly dressy wherever. I would suggest not blue jeans.")

She hangs up the phone and sighs, picking up her knitting needles.

She is nervous. And waiting for an iced tea. She has an infectious laugh, and marvelous skin the shade of a fresh, not-yet-ripe apricot and wears her hair parted on the side with a soft wave. On her fingers are three diamond rings and her ears are pierced with two-carat diamond studs. Her eyes are blue, lighter than her husband's, and she wears a gunmetal gray blouson dress fastened over a blouse with an oval pin.

She has the kind of look that women of her age and education and commitment tend to sport. Gutsy. Seasoned. Having dabbled in est and vegetarianism. We want to be taken seriously. You won't find us hanging out at the Lord & Taylor hosiery counter.

"I don't know how people can live and not spend a large part of their life thinking about what's happening right now," she says over the clicking of knitting needles. "Every time I look out the window, or walk out to my garden or do those corny things like picking roses or whatever, I think about it.

"It isn't like anything else. It isn't even like death, which we'll know will happen. It's something that none of us have ever been able to conceive of, and I personally cannot walk down a street or look at a beautiful countryside or a painting or listen to a piece of music without being aware that this is possibly going to be destroyed. Let alone everybody in the world. Everything humanity has created for 6,000 years. And for WHAT?"

Knit one, purl two.

The more she learned, she says, the more she read, the more she and Newman became involved in the issue of nuclear disarmament ("It's so silly to call it an issue when it's life or death"), the angrier she became. And the more hopeless.

"As Helen Caldicott said, 'I just want to be able to say to my children as the bombs come over, 'I tried.' "

Woodward is part of a growing number of American women becoming involved in the antinuclear effort.

"Women are an enormous force," she says. "And I don't think we've quite recognized that force. Or used it in a way that it can be. This the women's conference is a beginning. If it helps to mobilize that force, that's wonderful. Maybe that'll help."

Her first political experience was campaigning for Gore Vidal when he ran for the House of Representatives in the early 1960s. "I had no idea what to say. I used to take my baby along. My daughter was his godchild. I thought that should be sufficient reason for people to vote for him." She laughs. "Wasn't enough, unfortunately."

Woodward admits to being naive and unpolitical in her youth. "I realize I didn't even remember Hiroshima. I was 15 years old. What was I DOING?"

Dating?

"Dating," she concurs. "Going to a dance probably. It was a very naive world."

Not any more. "I'm always surprised when I see people having children now," she says. "It's a great act of courage or a great act of faith." She says if she were starting a family now, "I'd think about it more. I really don't know. I think unless there's some reason to believe things will change, why provide more fodder?"

Woodward became active in the 1960s in the peace movement, then several years ago became a member of the board of the Center for Defense Information, which describes itself as "an authoritative and impartial monitor of the military," concentrating on, among other things, reduced spending and averting nuclear war. (Part of the profits from the sale of Paul Newman's salad dressing and spaghetti sauce go to CDI.)

Is it easier for her to buttonhole politicians because she is Joanne Woodward?

"I don't know. I've never really given it much thought. If I am, because my name is recognizable, then terrific. I don't think those are important aspects, frankly. At any rate, I don't think it matters for what reason people listen. By listening to me or anybody. Joan Shmow. If it makes people change their awareness, then terrific. I'm a citizen. Why not use it?"

She exhales a sigh of impatience. "All of this about who I am and what I am and all of this . . ."

She's not into it.

"Nooo. I'm not," she laughs, saying she never liked any of the "accoutrements of being an actress except acting."

"The only thing that interests me is whether the conference begins to make people aware. If it does, I don't care for what reason it does."

She's never been a celebrity.

"Not willingly." She's growing testy. "What does this have to do with what we're doing?"

She says she would not combine her acting skills with a political message, particularly one like "The Day After."

"No. You know why? Because I think that putting something so dreadful into a film it makes it possible to conceive of. It was interesting to me to see the reaction to 'The Day After.' It was amazing. Then it was over. You can't dismiss it that lightly. It's not 'Disease of the Week.' There's no way we can relate to it. It's never happened to this world, and it never will again. Because once it happens, that's it. There's no way to talk about it in an easy fashion. I find it very difficult."

Her face flushes. "I'm angry because I think two countries in this world are playing games and they're playing games with the world and I don't know why and I don't think this should be allowed to happen."

She resists criticizing President Reagan's foreign policy, saying the question of nuclear disarmament "is beyond politics. I don't care who people vote for. If that person has a correct stand, and I think there is only one correct stand, that person should be voted into office. Whether they're Democrat, Republican or Watusi."

She covers her mouth with her hand. "I'm sorry, Watusis."

She feels optimistic, she says. "There's been a tremendous response from women all over the country. I think it provides a platform for women to express their opinion about what's been happening and to hopefully formulate a plan of action for women all over the country, and eventually all over the world, to follow.

"I think women need someplace to go to know what to do. You say will it? I don't know. I'd like to think so."

Today's conference is the culmination of a year's work.

"They're the ones who've done all the work," she says. "I'm the shill."

A small laugh. "There's a place in life for all of us."