"B" is for beer. . . er, belch. . . er, Busch.

Well, it's not exactly what every kid has in mind, but it's what they were toasting yesterday at the Children's Television Workshop.

CTW, the people who bring you Sesame Street and its wonderful world of whimsical characters and alphabet soup, announced it had entered into a joint venture with Anheuser-Busch Inc. to open a string of play parks called "Sesame Place."

All bubbles and cheer over the deal, the masters of educational kidvid were quick to play down the strangenes of their new association with the makers of Budweiser, the world's best-selling brew.

No, they said, Big Bird-a beaky, feathery, talkative Sesame Street regular-will not be sipping suds with his seeds. No, the Count will not start humming that old grown-up favorite, "Ninety-nine Bottles of Beer on the Wall." And no, there are no plans for Kermit the Frog to do impersonalions of Budweiser's super-salesman, Ed McMahon.

"There won't be a single Clydesdale anywhere in sight at the park," said Joan Cooney, CTW president, refer-ring to the king-sized horses that have pulled the Bud coach through hundreds of commercials.

In fact, CTW officials said they've had virtually no contact with the people at Anheuser-Busch who make the beer. Rather, they were drawn to the brewer because they were impressed with the management and talents of Busch Gardens, a subsidiary which operates large theme parks in Williamsburg, Va., and Tampa, Fla.

"We spent three years studying other parks and reviewing alternatives," Cooney said in an interview. "We liked the way they run their parks."

Construction of the first Sesame Place will begin in June on a 15-acre site in Lower Bucks County, Pa., about midway between Philadelphia and Trenton, N.J. The project is expected to cost about $6 million and is scheduled to open in the spring of 1980.

Hailed yesterday by its creators as "a new concept in commercial play at tractions," the park will be full of stuff designed to keep kids from preschool to pre-teenage laughing and scrambling all the way.

There won't be any trill rides or scary journeys along dark tracks. Dotted with jungle gyms, pole crawls and swamp walks, Sesame place will be more like an obstacle course than a traditional amusement park.

The park will include a large pavilion stocked with more than 60 computer-type games. And kids can learn all about gears, pulleys, windmills, water pumps and water wheels from science exhibits on display.

Throughout the park there will be references to many of the familar Sesame Street characters and themes.

What kind of refreshments will be served at the park's family restaurant? "There will not be any alcoholic beverages," Cooney said. "We're not even sure whether we'll have soft drinks. We would like to sell nutritious foods, not junk food.

"Actually," she added, "I'm concerned more about foods with lots of sugar than i am about beer."

Accustomed to dealing with critics in a field where sensitivities are easily aroused, Cooney said she expected to be criticized for choosing Busch.

But she defended CTW's venture into commercialism as necessary to keep the firm's other creative and educational activities going in the face of diminishing government support.

"We're criticized if we don't become self-supporting and we're criticized if we do," she said. CAPTION: Illustration 1 And 2, Sesame Street, Anheuser-Busch to open play parkes. By Robin Jareaux-The Washington Post