United States Nuclear Regulatory Commission - Protecting People and the Environment

Information Notice No. 84-19: Two Events Involving Unauthorized Entries into PWR Reactor Cavities

                                                            SSINS No.: 6835 
                                                            IN 84-19

                                UNITED STATES
                        NUCLEAR REGULATORY COMMISSION
                     OFFICE OF INSPECTION AND ENFORCEMENT
                            WASHINGTON, D.C. 20555

                                March 21, 1984

Information Notice No. 84-19: TWO EVENTS INVOLVING UNAUTHORIZED ENTRIES 
INTO PWR REACTOR CAVITIES

Addressees:

All nuclear power plant facilities holding an operating license (OL) or a 
construction permit (CP).

Purpose:

This information notice is provided as early notification of a recurring 
problem pertaining to unauthorized personnel entries into the cavity beneath 
the reactor vessel (reactor cavity) while the retractable incore detector
thimbles are withdrawn. Although these recent events did not result in 
personnel exposures in excess of regulatory limits, it was fortuitous that 
none of the workers remained in the reactor cavity for longer periods of
time.

It is expected that recipients will review this information for applicability 
to their facilities and consider actions, if appropriate, to preclude a 
similar problem occurring at their facilities. Suggestions contained in this 
information notice do not constitute NRC requirements and, therefore, no 
specific action or written response is required at this time. However, the
NRC  staff is considering the need for further regulatory action, because it
is  evident that some licensee high radiation area access control programs
are  inadequate to prevent unauthorized entries into areas where radiation
levels  of thousands of roentgens per hour (R/hr) can exist. Entry into
radiation  fields of this magnitude can seriously jeopardize the health and
safety of  personnel.

Description of Circumstances:

Event 1

On October 14, 1983, Turkey Point Unit 3 (Florida Power and Light) was in
cold  shutdown for refueling. While the reactor cavity was being filled and
with the  incore thimbles withdrawn, the shift technical adviser (STA) and
a roving  containment radiation protection technician (RPT) entered the
cavity area to  check for water leaks. Contrary to Technical Specification
requirements, the  STA and RPT did not obtain a special radiation work permit
(RWP) for the  cavity entry, did not comply with locally posted precautions
and instructions  at the cavity entry door, and did not possess a radiation
survey instrument  capable of 


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                                                            IN 84-19       
                                                            March 21, 1984 
                                                            Page 2 of 2

measuring radiation levels exceeding 5 R/hr. For the estimated sump stay-
time  of less than 1 minute, the STA and the RPT received whole-body doses
of 1.3  rem and 0.2 rem, respectively.

Event 2

On February 19, 1984, H. B. Robinson Unit 2 (Carolina Power and Light) was
in  cold shutdown for refueling, the reactor cavity was being filled, and the 
incore thimbles were withdrawn. While the RPT stayed near the cavity 
entranceway, a licensed reactor operator (RO) entered the cavity area to
check  for water leaks. Contrary to Technical Specification requirements, no
special  RWP was obtained for the entry and the guidance on the locally
posted warning  signs ("No Entry; contact Radiological Controls Foreman") on
the cavity  entrance door was ignored. The RO entered an unsurveyed area
(later found to  be approximately 75-100 R/hr) and received approximately 0.5
rem to the whole  body in about 30 seconds.

Discussion:

Appropriate enforcement actions have been proposed for the Turkey Point event 
(proposed $40,000 civil penalty) and are under consideration for the H. B. 
Robinson occurrence. The NRC staff is concerned since suggestions for reactor 
cavity access control made in Information Notice No. 82-51, "Overexposures in 
PWR Cavities" (issued December 21, 1982), if properly implemented, would have 
prevented these unauthorized cavity entries.

In both events personnel entered an area without fully understanding the 
radiological hazards present. The NRC staff is particularly concerned by this 
lack of awareness of the reactor cavity radiation hazards, since IN 82-51 
specifically stressed the importance of licensed senior ROs gaining an 
understanding of the magnitude of radiation hazard this area presents when
the  thimbles are withdrawn. In the case of the H. B. Robinson event, the
Shift  Foreman instructed the RO to enter the reactor sump, but did not give
explicit instructions for the methods to check for leaks, nor did the Shift
Foreman  caution the operator about the radiation hazards in the cavity area.

If you have any questions regarding this matter, please contact the Regional 
Administrator of the appropriate NRC Regional Office, or this office.

Edward L. Jordan, Director 
Division of Emergency Preparedness and Engineering Response 
Office of Inspection and Enforcement

Technical Contact: J. E. Wigginton, IE
                   (301) 492-4967

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