U.S. ATOMIC ENERGY COMMISSION 

REGULATORY 

DIRECTORATE OF REGULATORY STANDARDS 

REGULATORY GUIDE 1.86 

TERMINATION OF OPERATING LICENSES 

FOR NUCLEAR REACTORS

A. INTRODUCTION 

Section 50.51, "Duration of license, renewal," of 10 

CFR Part 50, "Licensing of Production and Utilization 

Facilities," requires that each license to operate a 

production and utilization facility be issued for a 

specified duration. Upon expiration of the specified period, the license may be either renewed or terminated 

by the Commission. Section 50.82, "Applications for 

termination of licenses," specifies the requirements that 

must be satisfied to terminate an operating license, 

including the requirement that the dismantlement of the 

facility and disposal, of the component parts not be 

inimical to the common defense and security or to the 

health and safety of the public. This guide describes 

methods and procedures considered acceptable by the 

Regulatory staff for the termination of operating 

licenses for nuclear reactors. The Advisory Committee 

on Reactor Safeguards has been consulted concerning 

this guide and has concurred in the regulatory position. 

B. DISCUSSION 

When a licensee decides to terminate his nuclear 

reactor operating license, he may, as a first step in the 

process, request that his operating license be amended to 

restrict him to possess but not operate the facility. The 

advantage to the licensee of converting to such a 

possession.only license is reduced surveillance require

ments in that periodic surveillance of equipment im

portant to the safety of reactor operation is no longer 

required. Once this possession-only license is issued, 

reactor operation is not permitted. Other activities 

related to cessation of operations such as unloading fuel 

from the reactor and placing it in storage (either onsite 

of offsite) may be continued.

June 1974

GUIDE

A licensee having a possession-only license- must 

retain, with the Part 50 license, authorization for special 

nuclear material (10 CFR Part 70, "Special Nuclear 

Material"), byproduct material (10 CFR Part 30, "Rules 

of General Applicability to Licensing of Byproduct 

Material"), and source material (10 CFR Part 40, "Licensing of Source Material"), until the fuel, radio

active components, and sources are removed from the 

facility. Appropriate administrative controls and facility 

requirements are imposed by the Part 50 license and the 

technical specifications to assure that proper surveillance 

is performed and that the reactor facility is maintained 

in a safe condition and not operated. 

A possession-only license permits various options and 

procedures for decommissioning, such as mothballing, entombment, or dismantling. The requirements imposed depend on the option selected. 

Section 50.82 provides that the licensee may dis

mantle and dispose of the component parts of a nuclear 

reactor in accordance with existing regulations. For 

research reactors and critical facilities, this has usually 

meant the disassembly of a reactor and its shipment 

offsite, sometimes to another appropriately licensed 

organization for further use. The site from which a 

reactor has been removed must be decontaminated, as 

necessary, and inspected by the Commission to deter

mine whether unrestricted access can be approved. In 

the case of nuclear power reactors, dismantling has 

usually been accomplished by shipping fuel offsite, 

making the reactor inoperable, and disposing of some of 

the radioactive components. 

Radioactive components may be either shipped off

site for burial at an authorized burial ground or secured

USAEC REGULATORY GUIDES Copies of published guides may be obtained by request indicating the divisions 

desired to the US. Atomic Energy Commission, Washington, D.C. 20545, Regulatory Guides are issued to describe ano make available to the public Attention: Director of Regulatory Standards. Comments and suggestions for methods acceptable to the AEC Regulatory staff of implementing specific parts of improvements in these guides are encouraged and should be sent to the Secretary the Commission's regulations, to delineate techniques ,1ed by the staff in of the Commission, U.S. Atomic Energy Commission, Washington, D.C. 20545, evaluating specific problems or postulated accidents, or to provide guidance to Attention: Chief, Public Proceedings Staff. applicants. Regulatory Guides are not substitutes for regulations and compliance with them is not required. Methods and solutions different from those set out in The guides are issued in the following ten broad divisions: the guides will be acceptable if they provide a basis for the findings requisite to the issuance or continuance of a oermit or license by the Commission. 1. Power Reactors 6. Products 

2. Research and Test Reactors 7. Transportation 3. Fuels and Materials Facilitie 8. Occupational Health Published guides will be revised periodically, as appropriate, to accQmmodate 4. Environmental and Siting 9. Antitrust Review comments and to reflect new information or experience. 5. Materials and Plant Protection 10. General
on the site. Those radioactive materials remaining on the 

site must be isolated from the public by physical barriers 

or other means to prevent public access to hazardous 

levels of radiation. Surveillance is necessary to assure the 

long term integrity of the barriers. The amount of 

surveillance required depends upon (1) the potential 

hazard to the health and safety of the public from 

radioactive material remaining on the site and (2) the 

integrity of the physical barriers. Before areas may be 

released for unrestricted use, they must have been 

decontaminated or the radioactivity must have decayed 

to less than prescribed limits (Table I). 

The hazard associated with the retired facility is 

evaluated by considering the amount and type of 

remaining contamination, the degree of confinement of 

the remaining radioactive materials, the physical security 

provided by the confinement, the susceptibility to 

release of radiation as a result of natural phenomena, 

and the duration of required surveillance. 

C. REGULATORY POSITION 

1. APPLICATION FOR A LICENSE TO POSSESS BUT 

NOT OPERATE (POSSESSION-ONLY LICENSE) 

A request to amend an operating license to a 

possession-only license should be made to the Director 

of Licensing, U.S. Atomic Energy Commission, Washing

ton, D.C. 20545. The request should include the 

following information: 

a. A description of the current status of the facility. 

b. A description of measures that will be taken to 

prevent criticality or reactivity changes and to minimize 

releases of radioactivity from the facility. 

c. Any proposed changes to the technical specifica

tions that reflect the possession-only facility status and 

the necessary disassembly/retirement activities to be 

performed. 

d. A safety analysis of both the activities to be 

accomplished and the proposed changes to the technical 

specifications. 

e. An inventory of activated materials and their 

location in the facility. 

2. ALTERNATIVES FOR REACTOR RETIREMENT 

Four alternatives for retirement of nuclear reactor 

facilities are considered acceptable by the Regulatory 

staff. These are: 

a. Mothballing. Mothballing of a nuclear reactor 

facility consists of putting the facility in a state of 

protective storage. In general, the facility may be left 

intact except that all fuel assemblies and the radioactive

fluids .and waste should be removed from the site. 

Adequate radiation monitoring, environmental surveil

lance, and appropriate security procedures should be 

established under a possession-only license to ensure that 

the health and safety of the public is not endangered. 

b. In-Place Entombment. In-place entombment con

sists of sealing all the remaining highly radioactive or 

contaminated components (e.g., the pressure vessel and 

reactor internals) within a structure integral with the 

biological shield after having all fuel assemblies, radio

active fluids and wastes, and certain selected com

ponents shipped offsite. The structure should provide 

integrity over the period of time in which significant 

quantities (greater than Table I levels) of radioactivity 

remain with the material in the entombment. An 

appropriate and continuing surveillance program should 

be established under a possession-only license. 

c. Removal of Radioactive Components and Dis

mantling. All fuel assemblies, radioactive fluids and 

waste, and other materials having activities above ac

cepted unrestricted activity levels (Table I) should be 

removed from the site. The facility owner may then have 

unrestricted use of the site with no requirement for a 

license. If the facility owner so desires, the remainder of 

the reactor facility may be dismantled and all vestiges 

removed and disposed of. 

d. Conversion to a New Nuclear System or a Fossil 

Fuel System. This alternative, which applies only to 

nuclear power plants, utilizes the existing turbine system 

with a new steam supply system. The original nuclear 

steam supply system should be separated from the 

electric generating system and disposed of in accordance 

with one of the previous three retirement alternatives. 

3. SURVEILLANCE AND SECURITY FOR THE RE

TIREMENT ALTERNATIVES WHOSE FINAL 

STATUS REQUIRES A POSSESSION-ONLY 

LICENSE 

A facility which has been licensed under a posses

sion-only license may contain a significant amount of 

radioactivity in the form of activated and contaminated 

hardware and structural materials. Surveillance and 

commensurate security should be provided to assure that 

the public health and safety are not endangered. 

a. Physical security to prevent inadvertent exposure 

of personnel should be provided by multiple locked 

barriers. The presence of these barriers should make it 

extremely difficult for an unauthorized person to gain 

access to areas where radiation or contamination levels 

exceed those specified in Regulatory Position C.4. To 

prevent inadvertent exposure, radiation areas above 5 

mR/hr, such as near the activated primary system of a 

power plant, should be appropriately marked and should 

not be accessible except by cutting of welded closures or 

the disassembly and removal of substantial structures

1.86-2
and/or shielding material. Means such as a &emote

readout intrusion alarm system should be provided to 

indicate to designated personnel when a physical barrier 

is penetrated. Security personnel that provide access 

control to the facility may be used instead of the 

physical barriers and the intrusion alarm systems. 

b. The physical barriers to unauthorized entrance 

into the facility, e.g., fences, buildings, welded doors, 

and access openings, should be inspected at least 

quarterly to assure that these barriers have not deterior

ated and that locks and locking apparatus are intact. 

c. A facility radiation survey should be performed at 

least quarterly to verify that no radioactive material is 

escaping or being transported through the containment 

barriers in the facility. Sampling should be done along the most probable path by which radioactive material 

such as that stored in the inner containment regions could be transported to the outer regions of the facility and ultimately to the environs. 

d. An environmental radiation survey should be 

performed at least semiannually to verify that no 

signficant amounts of radiation have been released to the 

environment from the facility. Samples such as soil, vegetation, and water should be taken at locations for 

which statistical data has been established during reactor 

operations. 

e. A site representative should be designated to be 

responsible for controlling authorized access into and 

movement within the facility. 

Sf. Administrative procedures should be established 

for the notification and reporting of abnormal occur

rences such as (I) the entrance of an unauthorized 

person or persons into the facility and (2) a significant change in the radiation or contamination levels in the 

facility or the offsite environment. 

g. The following reports should be made: 

(1) An annual report to the Director of Licensing, U.S. Atomic Energy Commission, Washington, D.C. 

20545, describing the results of the environmental and 

facility radiation surveys, the status of the facility, and 

an evaluation of the performance of security and 

surveillance measures. 

(2) An abnormal occurrence report to the Regula

tory Operations Regional Office by telephone within 24 

hours of discovery of an abnormal occurrence. The 

abnormal occurrence will also be reported in the annual 

report described in the preceding item. 

h. Records or logs relative to the following items 

should be kept and retained until the license is termi

nated, after which they may be stored with other plant 

records:

(1) Environmental surveys;- ' 

(2) Facility radiation surveyS; 

(3) Inspections of the physical barriers, and 

(4) Abnormal occurrences. 

4. DECONTAMINATION FOR RELEASE FOR UN

RESTRICTED USE 

If it is desired to terminate a license and to eliminate 

any further surveillance requirements, the facility should 

be sufficiently decontaminated to prevent risk to -the 

public health and safety. After the decontamination is 

satisfactorily accomplished and the site inspected by the Commission, the Commission may authorize the 

license to be terminated and the facility abandoned or 

released for unrestricted use. The licensee should per form the decontamination usiOg the following guide lines: '•' 

a. The licensee should make a reasonable effort to 

eliminate residual contamination. 

b. No covering should be applied to radioactive 

surfaces of equipment or structures by paint, plating, or 

other covering material until it is known that contamina

tion levels (determined by a survey and documented) are 

below the limits specified in 'Table I. In addition, a 

reasonable effort should be made (and documented) to 

further minimize contamination prior to any such 

covering. 

c. The radioactivity of the interior surfaces of pipes, drain lines, or ductwork should be determined by 

making measurements at all traps and other appropriate 

access points, provided contamination at these locations 

is likely to be representative d co6ntamination on the 

interior of the pipes, drain lines, or ductwork. Surfaces 

of premises, equipment, or scrip" which are likely to be 

contaminated but are of such size, construction, or 

location as to make the surface inaccessible for purposes 

of measurement should be assumed to be contaminated 

in excess of the permissable radiation limits. 

d. Upon request, the Commission may authorize a 

licensee to relinquish possession or control of premises, equipment, or scrap having surfaces contaminated in 

excess of the limits specified. This may include, but is 

not limited to, special circumstances such as the transfer 

of premises to another licensed organization that will 

continue to work with radioactive materials. Requests for such authorization should provide: 

(1) Detailed, specific information describing the 

premises, equipment, scrap, and radioactive contami

nants and the nature, extent, and degree of residual 

surface contamination.

1.86-3
(2) A detailed health and safety analysis indi

cating that the residual amounts of materials on surface 

areas, together with other considerations such as the 

prospective use of the premises, equipment, or scrap, are 

unlikely to result in an unreasonable risk to the health 

and safety of the public. 

e. Prior to release of the premises for unrestricted 

use, the licensee should make a comprehensive radiation 

survey establishing that contamination is within the 

limits specified in Table I. A survey report should be 

filed with the Director of Licensing, U.S. Atomic Energy 

Commission, Washington, D.C. 20545, with a copy to 

the Director of the Regulatory Operations Regional 

Office having jurisdiction. The report should be filed at 

least 30 days prior to the planned date of abandonment. 

The survey report should: 

(1) Identify the premises; 

(2) Show that reasonable effort has been made to 

reduce residual contamination to as low as practicable 

levels; 

(3) Describe the scope of the survey and the 

general procedures followed; and 

(4) State the finding of the survey in units 

specified in Table I. 

After review of the report, the Commission may 

inspect the facilities .to confirm the survey prior to 

granting approval for abandonment. 

5. REACTOR RETIREMENT PROCEDURES 

As indicated in Regulatory Position C.2, several 

alternatives are acceptable for reactor facility retirement. 

If minor disassembly or "mothballing" is planned, this 

could be done by the existing operating and mainte

nance procedures under the license in effect. Any 

planned actions involving an unreviewed safety question

or a change in the technical specifications should be 

reviewed' and approved in accordance with the require

ments of 10 CFR §50.59. 

If major structural changes to radioactive components 

of the facility are planned, such as removal of the 

pressure vessel or major components of the primary 

system, a dismantlement plan including the information 

required by §50.82 should be submitted to the Commis

sion. A dismantlement plan should be submitted for all 

the alternatives of Regulatory Position C.2 except 

mothballing. However, minor disassembly activities may 

still be performed in the absence of such a plan, 

provided they are permitted by existing operating and 

maintenance procedures. A dismantlement plan should 

include the following: 

a. A description of the ultimate status of the facility 

b. A description of the dismantling activities and the 

precautions to be taken. 

c. A safety analysis of the dismantling activities 

including any effluents which may be released. 

Sd. A safety analysis of the facility in its ultimate 

status. 

Upon satisfactory review and approval of the dis

mantling plan, a dismantling order is issued by the 

Commission in accordance with §50.82. When dis

mantling is completed and the Commission has been 

notified by letter, the appropriate Regulatory Opera

tions Regional Office inspects the facility and verifies 

completion in accordance with the dismantlement plan. 

If residual radiation levels do not exceed the values in 

Table I, the Commission may terminate the license. If 

these levels are exceeded, the licensee retains the 

possession-only license under which the dismantling 

activities have been conducted or, as an alternative, may 

make application to the State (if an Agreement State) 

for a byproduct materials license.

1.864
TABLE I

ACCEPTABLE SURFACE CONTAMINATION LEVELS

NUCLIDEa AVERAGEb c MAXIMUMb d j REMOVABLEb

U-nat, U-235, U-238, and 

associated decay products 

Transuranics, Ra-226, Ra-228, 

Th-230, Th-228, Pa-231, 

Ac-227, 1-125,1-129 

Th-nat, Th-232, Sr-90, 

Ra-223, Ra-224, U-232, 

1-126,1-131,1-133 

Beta-gamma emitters (nuclides 

with decay modes other than alpha 

emission or spontaneous fission) 

except Sr-90 and others noted above.

5,000 dpm a/100 cm2 

100 dpm/100 cm2 

1000 dpm[100 cm 2 

5000 dpm fl-,/ 100 cm 2

15,000 dpm a/1 00 cm 2 

300 dpm/ 100 cm2 

3000 dpm/ 100 cm2 

15,000 dpm 0-y/100 cm2

1,000 dpm a/100 cm2 

20 dpm/ 100 cm2 

200 dpm/100 cm2 

1000 dpm 3-,y/100 cm2

aWhere surface contamination by both alpha- and beta-gamma-emitting nuclides exists, the limits established for alpha- and 

beta-gamma-emitting nuclides should apply independently. 

bAs used in this table, dpm (disintegrations per minute) means the rate of emission by radioactive material as determined by correcting 

the counts per minute observed by an appropriate detector for background, efficiency, and geometric factors associated with the 

instrumentation. 

cMeasurements of average contaminant should not be averaged over more than 1 square meter. For objects of less surface area, the 

average should be derived for each such object. 

dThe maximum contamination level applies to an area of not more than 100 cm2 . 

eThe amount of removable radioactive material per 100 cm2 of surface area should be determined by wiping that area with dry filter or soft absorbent paper, applying moderate pressure, and assessing the amount of radioactive material on the wipe with an appropriate 

instrument of known efficiency. When removable contamination on objects of less surface area is determined, the pertinent levels 

should be reduced proportionally and the entire surface should be wiped.

1.86-5