Virginia Gov. Charles S. Robb, confronting what he called his "number one problem," tonight accepted "full responsibility" for the state's troubled prison system, which he said was "shell-shocked" by escapes and inmate disturbances.

Robb, focusing on prisons in the first three pages of a 10-page State of the Commonwealth speech, outlined to a joint session of the state legislature more than $10 million in proposed reforms to better train and pay guards, improve security and begin planning for a new maximum-security prison.

"In this period of frustration, when all of us have had our nerves rubbed raw . . . I can talk as tough as anyone," Robb said at one point. But he urged the legislators to avoid "lock-em-up-and-throw-away-the-key rhetoric" that could result in spending that "seems to punish the taxpayer more than the inmate . . . . Our prisons are neither torture chambers or country clubs," he said.

The prisons issue, sparked by the dramatic May 31, 1984, escape of six death row inmates from the state's Mecklenburg prison, is expected to dominate the 46-day legislative session that opened today and is seen as a volatile issue in next fall's statewide elections.

Some Republicans who had hoped to use the prison issue to their advantage were surprised by Robb's acceptance of responsibility. "He admitted all his sins," said Del. Vance Wilkins (R-Amherst). "I don't know what else we have to say."

The governor, delivering his 30-minute speech before the packed House chamber, also proposed a broad spending program for education, economic development, transportation, welfare and child abuse programs for the fiscal year that begins in July -- with most of the increases funded by a budget surplus that now is expected to reach $238 million.

Many of the details on how much the governor's programs will cost will be disclosed Thursday when Robb presents his budget package. It will include a pay raise of as much as 10.5 percent for some of the state's 75,000 employes, the governor said.

Robb defended his newly appointed corrections director, Allyn R. Sielaff, saying he is tough and fair. "He's going to have to make many more difficult and controversial decisions. . . . He has my full support and he's going to need yours, too."

Sielaff is Robb's third corrections director and recently raised the ire of legislators when he appeared to overreach his authority in ordering major changes at Mecklenburg.

Robb proposed an increase in state spending of $53 million to improve "standards of quality" in local school systems.

There already is money in the state budget for teacher and college faculty pay raises of 10 percent.

Robb noted that unexpected increases in the state sales tax -- part of which is sent to local governments -- will mean an additional windfall of about $40 million to local schools.

On other major issues, Robb said he would support a revision in the state's complicated highway funding formula to give more money to urban areas and he called again for raising the state's legal drinking age for beer to 21 from 19.

"I ask you to put this issue behind us," Robb said, referring to bitter fights over the issue in past sessions.

The governor also said he objects "strenuously to the federal government's coercive intrusion" on the drinking age by threatening to cut off federal highway funds if the age law is not raised.

Robb said he will propose allowing state employes to act as supplemental voting registrars to improve the state's low registration figures and to require more registration sites.

Robb also expressed renewed support for a "rights of the disabled" bill that was sidetracked by the legislature last year. The bill has been significantly watered down after objections by business interests, and today its legislative sponsor was warned in subcommittee to further weaken some of its provisions. The governor said he will support "environmentally safe" legislation to promote uranium mining and a coal slurry pipeline in Virginia, also banking across state lines and spending $3.5 million more to clean up the Chesapeake Bay, which would be added to the $13 million approved last year.

On public welfare issues, Robb said he would raise welfare benefit payments in the state's Aid to Dependent Children and Medicaid programs.

"No one who has seen the stark accounts from Africa can fail to be moved by the misery etched in the haunted eyes of Ethiopia's starving children," Robb said. "But human suffering exists at home as well." Robb said federal cutbacks will force the state to spend more to "stretch a new safety net" for Virginia's poorest citizens.

On Northern Virginia issues, Robb wants to spend $4 million to help build a new midfield terminal for Dulles International Airport "to promote further growth." The state also hopes to build a Center for Innovative Technology near there to attract more high-tech industries.

In Reaction to Robb's speech, Senate Majority Leader Hunter B. Andrews (D-Hampton) called the proposal for public education "a quantum leap forward." On the prison issue, he said Robb had "met the problem head-on" and defused the issue politically. Del. Arthur R. (Pete) Giesen (R-Waynesboro) praised Robb for taking steps to "take care of the immediate problem" with prisons but said he wasn't sure Robb was dealing with the long-range problems.

He also said the General Assembly would have to see if the pay increases and other Robb proposals are warranted.