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94

Information Notice No. 93­94: Unauthorized Forced Entry into the

Protected Area at Three Mile Island Unit 1 on February 7, 1993

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555

December 9, 1993

NRC INFORMATION NOTICE 93‐94: UNAUTHORIZED FORCED ENTRY INTO THE PROTECTED

AREA AT THREE MILE ISLAND UNIT 1 ON

FEBRUARY 7, 1993

Addressees

All holders of operating licenses or construction permits for nuclear power

reactors.

Purpose

The U.S. Nuclear Regulatory Commission (NRC) is issuing this information

notice to alert addressees of potential safety/safeguards issues raised as a

result of an unauthorized forced entry into a protected area at Three Mile

Island (TMI) Nuclear Generating Station. It is expected that recipients will

review the information for applicability to their facilities and consider

actions, as appropriate, to avoid similar problems. However, suggestions

contained in this information notice are not NRC requirements; therefore, no

specific action or written response is required.

Description of Circumstances

On February 7, 1993, TMI Unit 1 was operating at full power. At 6:53 a.m. an

intruder drove a station wagon into the TMI site entrance and continued past

the north gate guard house of the owner‐controlled area. The intruder was

traveling in the outbound traffic lane at an estimated 54‐64 km per hour

[35‐40 miles per hour]. After observing that the intruder had failed to stop

at a posted stop sign, the site protection officers at the north gate notified

other onsite protection officers, thus prompting security personnel to

respond. The vehicle then passed through a second stop sign and continued

toward the processing center building for the protected area, which it

skirted, heading toward the protected area gate.

The vehicle breached the gate, thus activating the protected area alarm system

and prompting security personnel to assess the situation on closed circuit

television. The vehicle proceeded approximately 57 m [189 feet] and crashed

through the Unit 1 turbine building aluminum rollup door. The vehicle caused

damage to a secondary system condensate resin liner, an auxiliary steam line,

and auxiliary support equipment.

The plant operators in the control room were notified of the event by a call

from the outgoing operations shift foreman who had witnessed the event and a
site protection officer who had been informed of the event by the north gate

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site protection officers. Control room personnel responded by implementing

emergency response procedures, including locking control room fire doors,

classifying the event as a site area emergency, performing required

notifications, and maintaining and monitoring the plant at full power.

The security staff responded by posting site protection officers to intervene

at predesignated vital areas, confirming vital area integrity, and with the

aid of offsite responders, assessing the threat and searching for the

intruder. The U.S. Army explosives ordnance disposal unit responded and

surveyed the vehicle for suspicious objects, conducted a search for explosive

devices, and removed the vehicle from the turbine building.

During the search‐and‐clear operations, TMI security personnel and offsite

response personnel found and apprehended the unarmed intruder at the bottom of

the turbine building in a small space under piping in the condenser area.

Following the operations shift supervisor declaring a site area emergency, the

site emergency response program was implemented and the Commonwealth of

Pennsylvania response organizations and the NRC were notified of the event.

Due to the potential security threat at the time, the licensee chose not to

fully activate its emergency response organizations. Personnel safety

considerations prompted a decision not to staff the inplant technical support

center or operations support center while the intruder was at large.

After visually inspecting plant equipment, verifying that operating plant

parameters were within the technical specification license criteria, and

confirming that the safety systems were available, the licensee ended the site

area emergency at 4:25 p.m.

On February 8, 1993, the NRC Executive Director for Operations directed that

an NRC incident investigation team be established to investigate the event.

The team consisted of NRC personnel with a broad knowledge of physical plant

security, safeguards, emergency planning, plant systems and operations, and

criminal investigation, and an industry representative.

Discussion

The incident investigation team findings and conclusions are contained in both

the public and safeguards versions of NUREG‐1485, "Unauthorized Forced Entry

Into the Protected Area at Three Mile Island Unit 1 on February 7, 1993,"

issued in April 1993. Some of the issues raised by the team with regard to

the event and subsequent declaration of a site area emergency are relevant to

operations at a power reactor site. These issues are summarized as follows:

(1) Protected Area Barriers and Assessment System

The performance objectives of Title 10 to the Code of Federal

Regulations (10 CFR) Part 73 do not specifically address preventing a

vehicle from forced entry through the protected area barrier and that

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there is no NRC guidance specific to performance standards for a

security response to such an intrusion. Notwithstanding this, the TMI

Unit 1 assessment system was not effective in observing the

intruder/vehicle penetrating the protected area barrier. Although the

protected area detection system functioned (alarmed) as designed, the

use of a land vehicle reduced the available time that security personnel

had to respond and significantly affected their strategy toward

protecting vital areas.

(2) Interface Between Operations, Emergency Response, and Physical Security Response Activities

Shortly after the protected area barrier was breached, the operator at

the central alarm station implemented a procedure to limit access to

vital areas. Implementation of the procedure reduced the number of key

cards that would open vital area doors and resulted in only one member

of the onshift operations crew having a valid key card to enter the

vital areas.

The TMI emergency operating procedure for responding to a penetration of

the protected area specified that the control room fire doors (which

were not vital area doors) be locked. A basis for this procedural

requirement was not established. Locking the fire doors isolated the

control room from the staff and equipment needed to implement the

emergency response plan and introduced potential problems for plant

operations.

The decision to maintain stable, steady‐state reactor operations at full

power during the security incident was in accordance with an established

emergency operating procedure and found to be appropriate by the

incident investigating team. However, the procedure did not contain

qualifying guidance to the operators. The incident investigating team

noted that maintaining stable, steady‐state operations at full power may

not be appropriate for all security event conditions covered by the

procedure.

(3) Effect of security on Licensee Emergency Response and on Emergency Plan

Implementation

The shift operations supervisor was initially distracted from making the

event classification and emergency declaration partly because of

personnel safety concerns. His first priority was to lock the fire

doors to the control room. Personnel safety considerations also

prompted a decision not to staff the normal designated in‐plant

technical support center or the operations support center which are

located in the control tower. Instead, an ad hoc decision was made to

direct the technical support center and operations support center

personnel to the training center. In addition, the Emergency Director

responded to the central alarm station, which had the effect of

relocating the emergency control center from the control room area to

the service building. This relocation created confusion and complicated

implementation of the emergency response plan. The licensee focused on

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re‐establishing the security of the facility and eliminating the

intruder, thus obscuring the broader emergency response measures

required for potential radiological sabotage.

(4) Process for Implementing 10 CFR 50.54(x) and (y) Provisions
During the event, the licensee suspended normal security entry

processing into the protected area to allow offsite personnel to have

free access to the vehicle and to conduct associated investigations.

Routine security checks and records also were suspended. Although the

suspension of security requirements is addressed in 10 CFR 50.54(x) and

(y), compensatory alternatives were not considered in their application

during this event. Additionally, the licensee did not report to the NRC

Operations Center that it had suspended certain security measures in

accordance with the provision of 10 CFR 50.54(x).

(5) Communications Systems

During the event, several difficulties arose that adversely affected

communications with offsite organizations and licensee emergency

response staff. Only certain telephones were specified by procedures to

be used for emergency notifications and callbacks, and these telephones

were not accessible because the control room fire doors were locked.

The individuals making notifications and callbacks were not trained in

the procedures they were to follow. Although the central alarm station

was used as the emergency control center, the central alarm station

communications capability was not designed to support both emergency

preparedness and security functions. Also, the licensee telephone

system had an off‐hours restriction that did not permit outgoing calls

from certain telephones. This restriction was not completely lifted

until 7.5 hours after the intruder penetrated the protected area. In

addition, the NRC did not have access to information in the emergency

response data system because of a telephone line failure at TMI.

The above items illustrate a broad spectrum of activities that were not

anticipated or covered by procedures. While it cannot be expected that every

variable of a security event can be anticipated in advance, there may be some

lessons learned from the event that can be applied generally. On the basis of

the NRC incident investigation team findings with respect to this event, the

NRC staff is considering the need for additional regulatory actions.

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This information notice requires no specific action or written response. If

you have any questions about the information in this notice, please contact

one of the technical contacts listed below or the appropriate Office of

Nuclear Reactor Regulation (NRR) project manager.

/S/'D BY BKGRIMES

Brian K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

Technical contacts: Michael S. Warren, NRR

(301) 504‐3211

Donald M. Carlson, NRR

(301) 504‐3212

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