WASHINGTON (Reuters) - Enrollment in health insurance plans on the troubled Obamacare website was very small in the first couple of days of operation, with just 248 Americans signing up, according to documents released on Thursday by a U.S. House of Representatives committee.

The Obama administration has said it cannot provide enrollment figures from HealthCare.gov because it doesn't have the numbers. The federal website, where residents of 36 states can buy new healthcare plans under President Barack Obama's law, was launched on October 1.

"We do not have any reliable data around enrollment, which is why we haven't given it to date," Health and Human Services Secretary Kathleen Sebelius told lawmakers on Wednesday.

But the documents, which are labeled "war room" notes and appear to be summaries of issues with the problematic website beginning on October 2, indicate a mere six enrollments had occurred by that morning - the day after the website was launched and almost immediately crashed.

"High capacity on the website, direct enrollment not working," the October 2 notes said. By later that day, "approximately 100" enrollments had taken place.

"As of yesterday, there were 248 enrollments," said the notes from the morning of October 3.

The documents were released by the House Oversight and Government Reform Committee, which has been demanding information from the administration about the website's problems. The committee is chaired by Representative Darrell Issa, a Republican opponent of Obamacare.

The notes were from meetings at the Centers for Medicare and Medicaid Services, the arm of the Health and Human Services Department that has been overseeing the website, an Issa spokeswoman said. The documents were first reported by CBS News.

Health and Human Services spokeswoman Joanne Peters said the department will release Obamacare enrollment statistics on a monthly basis after coordinating information from different sources. This will including call centers, paper applications for insurance, and data from insurers and states. The first release of enrollment data will likely be mid-November, she said.

"These appear to be notes, they do not include official enrollment statistics," Peters said of the documents Issa's panel released.

"As the secretary (Sebelius) said before Congress, we are focused on providing reliable and accurate information and we do not have that at this time ... We have always anticipated that the pace of enrollment will increase throughout the enrollment period."

HealthCare.gov has been plagued with technology problems since its rollout. It was back up on Thursday after not being fully functional for much of Wednesday.

Both the federal exchange and the exchanges built by 14 other states and Washington D.C. were set up to let residents enroll in new plans created under the Affordable Care Act, Obama's 2010 healthcare reform law commonly known as Obamacare.

The government has said it expects about 7 million people to enroll for individual insurance in 2014, many of whom are expected to receive government subsidies.

EXPERTS BROUGHT IN

The Obama administration said it has brought in experts from top technology companies including Google Inc and Oracle Corp to fix the HealthCare.gov website, as Republicans press for details about the botched October 1 launch.

Health and Human Services said it had added dozens of technology experts and engineers to its round-the-clock effort to fix the technical glitches on the site that is key to the implementation of Obama's healthcare restructuring law.

Giving some of the first details of who might be leading the tech fix, HHS officials identified two experts by name: Michael Dickerson, a website reliability engineer on leave from Google, and Greg Gershman, a Baltimore-based innovation director with the firm Mobomoand who previously worked for the White House and the General Services Administration.

"We are doing everything we can to assist those contractors to make HealthCare.gov a highly performant, highly reliable, highly secure system," Oracle CEO Larry Ellison told shareholders at the company's annual meeting on Thursday in Redwood City, California. There was no comment from Google.

The Obama administration says it is confident it will have the website running smoothly by November 30, giving people enough time to enroll in health plans to receive coverage beginning on January 1. Failure to do so would jeopardize its goal of signing up enough consumers, particularly young and healthy ones, to the new online insurance exchanges, and would provide more ammunition to Republican efforts to delay or kill the 2010 law.

Issa said he had subpoenaed Sebelius for more information on the website's technical problems, including how it was tested, and enrollment data. The subpoena requires the documents to be produced by November 13.

"The evidence is mounting that the website did not go through proper testing, including critical security testing, and that the administration ignored repeated warnings from contractors about ongoing problems," Issa said in a statement.

The administration has launched what it calls a "tech surge" to fix the website's problems, largely centered on two existing contractors who were paid to build its underlying technology - CGI Federal and Quality Software Services Inc, a unit of UnitedHealth Group.

The contractors already were using technology from Oracle in building the site. Experts from Red Hat Inc are also among the repair effort, a U.S. official said on Thursday.

Individuals from Oracle and Red Hat have expertise in site reliability, stability and scalability, according to a blog post by Julie Bataille, spokeswoman for CMS.

She said Dickerson, the expert on leave from Google, would be working for Quality Software Services Inc (QSSI), while Gershman would be working for CGI Federal, "so they are employees of those particular companies" during the work involved. Administration and company officials gave no further details on how much help was being provided.

(Additional reporting by Noel Randewich and Jim Finkle; Editing by Michele Gershberg, Paul Simao and Christopher Wilson)