The nation can "reasonably expect" that half the people required to register for the draft in a future emergency will declare themselves conscientious objectors, according to an internal Selective Service report released yesterday.

A Selective Service representative said the report was one man's opinion, not the agency's, while Rep. Robert W. Kastenmeier (D-Wis.) asserted it represents a "shocking" inside view that has yet to be officially disavowed by the Carter administration.

Released by Kastenmeier at a news conference, it was written last September by Donald Guritz, a former Selective Service regional counsel for six Midwestern states. The report recommends a series of stringent measures to deal with the "enormous problems" presented by conscientious objectors.

The federal government should draft emergency legislation to effect "complete rescission of the conscientious-objector exemption" or at least restrict it to "practicing members of religious sects that specifically prohibit participation in military service," the report said.

Also, Selective Service should have the final say on whether someone is qualified for the conscientious-objector exemption to military service. "Claims shall not be subject to review by any other agency, official or court of the United States in any manner or any proceeding whatever," the report stated.

Those who are granted conscientious objector status, the report continued, should be severely taxed "in lieu of military or alternate service.

"This might include," the report continued, " a property tax taking all property owned in any amount exceeding $500 (exceeding work tools, etc.), coupled with an income tax amounting to a virtual forfeiture of all incomre of more than $5,000 per year for a period anywhere from five to 20 years.

"While this is a novel idea," the report said, "it does have a certain appeal and should be kept in mind for use at some future time."

Guritz, the report's author, in the papers obtained by Kastenmeier said he was a Phi Beta Kappa graduate of Northwestern University, served as an Air Force legal officer from 1966 to 1971 and then worked for Selective Service in Chicago until 1973 as a councel for the region of Minnesota, Wisconsin, Michigan, Illinois, Indiana and Ohio.

"I dealt almost exclusively with problem cases," Guritz wrote in his biography, "so that my experience at that time with respect to conscientious objectors was mainly limited to those who were recalcitrants and political radicals."

He said the Vietnam experience together with the recent court decisions liberalizing the law on who could qualify as a conscientious objector were the basis for his prediction that about half the people called to register would claim conscientious-objector status. He wrote the report released yesterday while serving as an Air Force major doing two weeks of reserve duty at Selective Service's Washington headquarters.

Selective Service assistant John Lamb said yesterday that Guritz's report "doesn't represent an inside view of the agency. It was his thinking; just a training exercise. We said thanks but no thanks."

President Carter has recommended that the nation's 8 million 19- and 20-year-old men and women be registered for the draft this year. He has the authority, but not the money, to begin registration of men. He needs congressional legislation to register women. Congress will not give him that authority this year.

This leaves the question of whether Congress will provide the $13.3 million the president needs to finance the registration of men. The House Appropriations committee may vote on that question today when a resolution is offered to transfer $13.3 million from the Pentagon to Selective Service to finance the men-only registration.