No roles are totally secure in the world of the soaps. But among the safest are the shrews. Without them, daytime television would be like stew without salt. John Conboy, executive producer of "The Young and Restless," believes "a bitch goddess can go on indefinitely, as long as you temper her with softness and give her reasons for being."

The shrews are the women you love to hate, the women who cause the great conflicts on the daytime serials. Among them: Beverlee McKinsey (formerly Iris on "Another World," now with "Texas"), Marie Cheatham (Stephanie on "Search for Tomorrow"), Eileen Fulton (Lisa on "As the World Turns"), Randall Edwards (Delia on "Ryan's Hope"), Brenda Dickson (until recently Jill on "The Young and Restless"), Susan Lucci (erica on "All My Children") and Susan Seaforth Hayes (Julie on "Days of Our Lives").

Every serial must have a shrew for dramatic conflict. She is the troublemaker who does everything that the viewer would like to do but can't.

Susan Seaforth Hayes' trials during the 11 years she has played Julie on "Days of Our Lives" are more than typical. Experts say she has suffered the most. She started as a teen-ager who stole a fur coat, and was headed wrong from the beginning. She fell in love with the wrong person, became pregnant and gave the baby away. She tried to murder her best woman friend. She has married twice, not for love, and was untrue to her husbands. She was raped, but didn't get pregnant from the act of violence. Finally she did marry her true love, was accused of murder, was badly burned and scarred in a fire, and then divorced her true love. But they might get back together again. Maybe.

Hayes insists that she hasn't been a shrew for a long time. "She no longer plots or seeks revenge, and she's gotten less interesting. They changed the character, because they needed a sympathetic one. We've justified Julie's bad behavior and scenes of conflict."

Author and soap expert Alan Gansberg agrees. "She's become a goodnik. She made peace with her mother, she had a good marriage, brought back her son and she has mellowed." But co-executive producer Al Rabin disagrees. "Julie has been a great bitch goodess for 11 years, and I see no end in sight. You always have that feeling that Julie can turn on you, she could snap your head right off."

Hayes thinks bitch goddesses are outdated cliches: "It goes back to the old days of soaps, when women with careers were bad. The good women stayed home, as madonnas. Family and motherhood were good. Money was bad, and the girl who had sex with a man just for the sake of sex was bad. When I was on "The Young Marrieds' years ago, the good girl who wanted to save her marriage quit work to stay home."

When the shrews grow older, they may lose some of their goddess glow, but bitchiness goes on forever: They become meddling dowagers.

Among the more noteworthy are former movie star Ruth Warrick (Phoebe on "All My Children"), Lois Kibbee (Geraldine on "Edge of Night") and the worst of all -- Vanessa on "The Young and Restless," played by veteran soap star K. T. Stevens (who was in the original cast of "General Hospital").

Conboy says, "Vanessa is one of the great manipulators of all time. Her motivations are due to panic that she will lose whatever she has."

Stevens, a veteran of Broadway plays and New York soaps, cherishes her rotten role. "I am the power behind the throne of the Prentiss family's multinational corporations. I am perhaps the richest lady in the world," she says with satisfaction.

The actresses interviewed for this series are, for the most part, content in their roles and have no intention of leaving unless their story lines come to an end. But all is not sweetness and light for every actor on every soap. A couple of male actors, who asked to remain anonymous, have said there is an unwritten policy at the networks: If you're on a daytime show, you stay in daytime.

Conboy and ABC executive Jacqueline Smith say it's not so. "It's not true that actors are locked into soaps here. It may be true on the East Coast, because there's nothing else to do," Conboy says. bAnd Smith is even more vehement: "We encourage our daytime people to do movies of the week. And Joyce Selznick, who is doing special casting for the network, has her eye on daytime all the time."

Some actors make it from daytime to prime time. But some don't. One example is William Gray Espy, who was the sex symbol of "The Young and Restless in the role of Snapper. When he left in 1976, he and everyone else believed it was for big stardom. He did some theater in the South and traveled around the world with a knapsack. He was to be in the "American Gigolo," but his part was written out at the last minute. He returned to daytime, and is now seen on "Another World" as Mitch.

The same fate befell Janice Lynde, who was the original concert pianist on the same show. She too quit for prime time, appeared in a few episodes of a series, and is again a regular on "Another World."

Trish Stewart, however, walked away from "The Young and Restless" and got luckier: prime-time episodes and a co-starring role on Andy Griffith's short-lived "Salvage I" series. Her co-star on the Andy Griffith show was also a soaper, Joel Higgins, who graduated from "Search for Tomorrow."

When soap actors are replaced for whatever reason, there is never a word of explanation to the audience.

A few years ago, Emily McLaughlin (Jessie on "General Hospital") was hospitalized for six weeks with bleeding ulcers. Aneta Corsaut replaced her, and no one wrote a letter or made a phone call. The women look somewhat alike, so it might be assumed that viewers didn't notice the substitution.

When Francesca James (Kitty on "All My Children") wanted to leave, the writers let her die, and her death scenes were widely popular. When Francesca wanted to return to the show, facile typewriters made that possible too: She returned as her long-lost sister, Kelly.

When Susan Flannery opted to leave her role of Laura, the psychiatrist, on "Days of Our Lives," equally blond Susan Oliver stepped into the role, without explanation, as usual. And when she departed, Rosemary Forsythe, also blond, took over. Now the character has been retired for the indefinite future, because there is a new team of writers on the show.