P.I 

8172 

ojflo; Ffft-l 

Federal Register / Vol. 52, No. 50 / Monday, March 16, 1987 / Proposed Rules 

-7-

40 CFR Part 302 

[FR-3122-71 

Reportable Quantity Adjustment— 

Radionuclides 

AGENCY: U.S. Environmental Protection 

Agency (EPA). 

ACTION: Proposed rule. 

SUMMARY: Sections 103(a) and 103(b) of 

the Comprehensive Environmental 

Response, Compensation, and Liability 

Act of 1980 (CERCLA), as amended, 

require that persons in charge of vessels 

or facilities from which a hazardous 

substance has been released in 

quantities equal to or greater than its 

reportable quantity (RQ) immediately 

notify the National Response Center of 

the release. Section 102(b) of CERCLA 

establishes RQs for releases of 

designated hazardous substances at one 

pound, except those for which RQs have 

been established pursuant to section 

311(b)(4) of the Clean Water Act (CWA). 

Section 102(a) authorizes the 

Administrator of the U.S. Environmental 

Protection Agency (EPA) to adjust RQs 

for hazardous substances and to 

designate as hazardous substances 

those substances which, when released 

into the environment, may present 

substantial danger to the public health 

or welfare or the environment. The RQ 

for radionuclides established by 

CERCLA is one pound and has not been 

adjusted by regulation. EPA recognizes 

that this RQ may not be appropriate 

because releases of much less than one 

pound, of radionuclides may present a 

substantial threat to public health or 

welfare or the environment. This 

proposed rule adjusts the RQ for 

radionuclides established under section 

102(b). This RQ adjustment is intended 

to allow EPA to focus its resources on 

the most serious releases and to protect 

public health and welfare and the 

environment more effectively. 

DATES: Comments must be received on 

or before May 15,1987. 

ADDRESSES: The toll-free telephone 

number of the National Response Centei 

is 1-800/424-8802; in the Washington, 

DC metropolitan area the number is 1-

202/426-2675. 

Comments: Comments should be 

submitted in triplicate to: Emergency 

Response Division, Docket Clerk, 

Attention: Docket Number 102RQ-RN, 

Room LG-100, U.S. Environmental 

Protection Agency, 401 M Street, SW, 

Washington, DC 20460. 

Docket: Copies of materials relevant 

to this rulemaking are kept in Room LG100 at the above address. The docket is 

available for inspection between 9:00 

a.m. and 4:30 p.m. Monday through 

Friday, excluding federal holidays. As 

provided in 40 CFR Part 2, a reasonable 

fee may be charged for copying services. 

FOR FURTHER INFORMATION CONTACT: 

Ms. Barbara Hostage, Project Officer 

Response Standards and Criteria 

Branch, Emergency Response Division 

(WH-548B) U.S. Environmental 

Protection Agency, 401M Street SW, 

Washington, DC 20460 

or the 

RCRA/Superfund Hotline, 1-800/424-

9346; in Washington. DC, 1-202/382-

3000. 

SUPPLEMENTARY INFORMATION: The 

contents of today's preamble are listed 

in the following outline: 

I. Introduction. 

A. Statutory Authority. 

B. Background of this Rulemaking. 

II. Releases Covered by this Notice. 

A. Hazardous Substances Subject to this 

Notice. 

B. Definition of Releases Subject to this 

Notice and Statutory Exemptions. 

III. Duplicate Reporting/Regulatory 

Consistency. 

IV. Reportable Quantity Adjustments for 

Radionuclides. 

A. Introduction and Previous RQ 

Adjustment Methodology. 

B. Options Considered and Radionuclide 

RQ Methodology. 

C. Alternative Approaches. 

D. Reporting Requirements for Mixtures of 

Radionuclides. 

E. Other Issues. 

V. Summary of Supporting Analyses. 

I. Introduction 

A. Statutory Authority 

The Comprehensive Environmental 

Response, Compensation, and Liability 

Act of 1980 (Pub. L. 96-510), 42 U.S.C. 

9601 et seq. (Superfund, CERCLA, or the 

Act), as amended by the Superfund 

Amendments and Reauthorization Act 

of 1986 (Pub. L. 99^499) (SARA), 

establishes broad federal authority to 

respond to releases or threats of 

releases of hazardous substances from 

vessels and facilities. Section 101(14) of 

the Act defines the term "hazardous 

substances" by reference to other 

environmental statutes. Section 102 of 

CERCLA gives the Environmental 

Protection Agency (EPA) authority to 

designate additional hazardous 

substances. Currently, there are 717 

CERCLA hazardous substances. 

Section 103 of the Act requires the 

person in charge of a vessel or facility ' 

to notify the National Response Center 

immediately when there is a release of a 

hazardous substance in an amount 

equal to or greater than the reportable 

quantity (RQ) for that substance.2 

Section 102(b) of CERCLA establishes 

RQs for releases of hazardous 

substances at one pound, except for 

those substances for which RQs were 

established pursuant to section 311 of 

the Clean Water Act (CWA). Section 

102(a) of CERCLA authorizes EPA to 

adjust all of these RQs by regulation. 

A major purpose of the section 103 (a) 

and (b) notification requirement is to 

alert the appropriate government 

officials to releases of hazardous 

substances that may require a federal 

response to protect public health and 

welfare and the environment. Under 

section 104 of the Act, the federal 

government may respond whenever 

there is a release or a substantial threat 

of a release of a hazardous substance 

into the environment. Response 

activities are to be taken, to the extent 

practicable, in accordance with the 

National Contingency Plan (NCP) (40 

CFR Part 300), which was developed 

originally under the CWA and which 

has been revised to reflect the 

responsibilities and authority created by 

CERCLA.3 EPA emphasizes that a 

hazardous substance release 

notification is merely a trigger for 

informing the government of a release so 

that the appropriate federal personnel 

can evaluate the need for a federal 

removal or remedial action and 

undertake any necessary action in a 

timely fashion. Federal personnel will 

evaluate all reported releases, but wiL. 

not necessarily initiate a removal or 

remedial action in response to all 

reported releases, because the release of 

an RQ will not necessarily pose a 

hazard to public health or welfare or the 

environment in all circumstances. 

Government personnel will assess each 

reported release on a case-by-case basis 

to determine the appropriate action. In 

1

 For this proposed rule on radionuclides, it is 

important to consider the CERCLA definition of 

"facility" in section 101(9). A number of consumer 

products such as watches and smoke detectors maycontain (and at some point release) radionuclides. 

The CERCLA definition of "facility" specifically 

excludes any consumer product in consumer use; 

thus any release of radionuclides from such 

products when in consumer use are not subject to 

the notification requirements discussed in this 

proposed rule. 

8

 A release into the environment of a substance 

which is not listed as a CERCLA hazardous 

substance but which rapidly forms a CERCLA 

hazardous substance upon release is subject to the 

notification requirements of section 103. If the 

amount of the hazardous substance formed as such 

a reaction product equals or exceeds the RQ for that 

substance, the release must be reported to the 

National Response Center. 

3

 The NCP is being revised presently to ensure 

that responses to releases of radionuclides also will 

be undertaken consistent with the Federal 

Radiological Emergency Response Plan (FRERP). 
P.2 

Federal Register / Vol. 52, No. 50 / Monday, March 16, 1987 / Proposed Rules 8171 

TABLE 117.3—REPORTABLE QUANTITIES OF HAZARDOUS SUBSTANCES— 

Continued 

Material Category RQ in pounds (kilograms) 

Sodium bisulfite 

Sodium chromate 

Sodium cyanide 

Sodium dodecylbenzenesulfonate.. 

Sodium fluoride 

Sodium hydrosulfide 

Sodium hydroxide 

Sodium hypochlorite 

Sodium methylate 

Sodium nitrite 

Sodium phosphate, dibasic 

Sodium phosphate, tribasic 

Sodium selenite 

Strontium chromate 

Strychnine 

Styrene 

Sulfuric acid 

Sulfur monochloride 

2,4,5-T acid 

2,4,5-T amines 

2,4,5-T esters 

2,4,5-T salts 

TDE 

2,4,5-TP acid 

2,4,5-TP acid esters 

Tetraethyl lead 

Tetraethyl pyrophosphate 

Thallium sulfate 

Toluene 

Toxaphene 

Trichlorfon 

trichloroethylene 

Trichlorophenol 

Triethanolamine 

dodecylbenzenesulfonate. 

Triethylamine 

Trimethylamine 

Uranyl acetate 

Uranyl nitrate 

Vanadium pentoxide 

Vanadyl sulfate 

Vinyl acetate 

Vinylidene chloride 

Xylene 

Xylenol 

Zinc acetate 

Zinc ammonium chloride 

Zinc borate 

Zinc bromide 

Zinc carbonate 

Zinc chloride 

Zinc cyanide 

Zinc fluoride 

Zinc formate 

Zinc hydrosulfite 

Zinc nitrate 

Zinc phenolsulfonate 

Zinc phosphide 

Zinc silicofluoride 

Zinc sulfate 

Zirconium nitrate 

Zirconium potassium fluoride 

Zirconium sulfate 

Zirconium tetrachloride 

D 

X 

A 

C 

C 

D 

C 

B 

C 

B 

D 

D 

B 

X 

A 

C 

C 

C 

C 

D 

C 

C 

X 

B 

B 

A 

A 

B 

C 

X 

B 

B 

A 

C 

D 

B 

B 

B 

C 

C 

D 

B 

C 

C 

C 

C 

C 

C 

C 

C 

A 

C 

C 

C 

C 

D 

B 

D 

C 

D 

C 

D 

D 

5,000 (2,270) 

1 (0.454) 

10 (4.54) 

1,000 (454) 

1,000(454) 

5,000 (2,270) 

1,000(454) 

100(45.4) 

1,000(454) 

100 (45.4) 

5,000 (2,270) 

5,000 (2,270) 

100(45.4) 

1 (0.454) 

10(4.54) 

1,000 (454) 

1,000 (454) 

1,000(454) 

1,000 (454) 

5,000 (2,270) 

1,000(454) 

1,000 (454) 

1 (0.454) 

100 (45.4) 

100 (45.4) 

10 (4.54) 

10 (4.54) 

100 (45.4) 

1,000(454) 

1 (0.454) 

100 (45.4) 

100 (45.4) 

10(4.54) 

1,000(454) 

5,000 (2,270) 

100(45.4) 

100(45.4) 

100 (45.4) 

1,000(454) 

1,000(454) 

5,000 (2,270) 

100 (45.4) 

1,000(454) 

1,000 (454) 

1,000 (454) 

1,000(454) 

1,000 (454) 

1,000(454) 

1,000(454) 

1,000 (454) 

10(4.54) 

1,000(454) 

1,000(454) 

1,000(454) 

1,000(454) 

5,000 (2,270) 

100 (45.4) 

5,000 (2,270) 

1,000(454) 

5,000 (2,270) 

1,000(454) 

5,000 (2,270) 

5,000 (2,270) 

[FR Doc. 87-344 Filed 3-13-87; 8:45 am] 

BILLING. CODE 6560-50 , 
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Federal Register / Vol. 52, No. 50 / Monday, March 16, 1987 / Proposed Rules 8173 

certain limited situations, when direct 

reporting to the National Response 

Center is not practicable, the person in 

charge may report to the nearest Coast 

Guard- or EPA-predesignated On-Scene 

Coordinator (OSC). If it is not possible 

to notify the National Response Center 

or predesignated OSC immediately, 

reports may be made immediately to the 

nearest Coast Guard unit, provided that 

the person in charge notifies the 

National Response Center as soon as 

possible (40 CFR § 300.63(b) and 33 CFR 

§ 153.203). 

Section 103(b) of CERCLA authorizes 

penalties, including criminal sanctions, 

for persons in charge of vessels or 

facilities who fail to report releases of 

hazardous substances which equal or 

exceed RQs. Section 109 of SARA 

amends section 103(b) of CERCLA, 

increasing the maximum penalties and 

years of imprisonment. Any person who, 

as soon as that person has knowledge of 

a reportable release, fails to report the 

release immediately pursuant to section 

103(b) or who submits any information 

which he knows to be false or 

misleading, shall, upon conviction, be 

fined in accordance with the applicable 

provisions of Title 18, United States 

Code (not more than $250,000 or 

$500,000, depending upon whether the 

violator is an individual or an 

organization), or imprisoned for not 

more than three years (or not more than 

five years for second and subsequent 

convictions), or both. Notifications 

received under section 103(b) or 

information obtained by exploitation of 

such notifications cannot be used 

against any reporting person in any 

criminal case, except a prosecution for 

perjury or for giving a false statement. 

Section 109 of SARA also provides for a 

system of administrative penalties for 

violations of CERCLA section 103(b), 

enforceable through civil proceedings. 

B. Background of this Rulemaking 

On May 25,1983, EPA proposed a rule 

(48 FR 23552) to clarify procedures for 

reporting releases and to adjust RQs for 

387 of the then 696 CERCLA hazardous 

substances. That Notice of Proposed 

Rulemaking (NPRM) also listed, for the 

first time, the "hazardous substances" 

designated by section 101(14) of 

CERCLA. The NPRM discussed in detail 

the CERCLA notification provisions 

including the persons required to notify 

the National Response Center of a 

release, the substances for which 

notification is required, the types of 

releases subject to the notification 

requirements, the exemptions from these 

notification requirements, the 

methodology and criteria used to adjust 

the RQ levels, and the adjustments 

proposed under section 102 of CERCLA 

and under section 311 of the CWA. 

These issues were discussed further in 

the preamble to a rule making final 340 

of the 387 proposed RQs, published on 

April 4,1985 (50 FR 13456). They will be 

discussed again in this preamble only to 

the extent that EPA needs to provide 

additional explanation of these issues in 

the specific context of adjusting RQs for 

releases of radionuclides. 

It should be noted that other 

provisions of CERCLA may apply even 

where the statute does not require 

notification. Therefore, nothing in this 

rulemaking should be interpreted as 

reflecting Agency policy or the 

applicable law with respect to other 

provisions of the Act. For example, 

unless specifically exempted under 

CERLCA, a party responsible for a 

release is liable for the costs of cleaning 

up that release and for any natural 

resource damages caused by the release, 

even if the release is not subject to the 

notification requirements of sections 103 

(a) and (b). Similarly, proper reporting of 

a release in accordance with sections 

103 (a) and (b) does not preclude 

liability for cleanup costs. The fact that 

a release of a hazardous substance is 

properly reported or that it is not subject 

to the notification requirements of 

sections 103 (a) and (b) will not prevent 

EPA or other governmental agencies 

from taking response actions under 

section 104, seeking reimbursement from 

responsible parties under section 107, or 

pursuing an enforcement action against 

responsible parties under section 106. 

Note also that this proposed rule does 

not affect hazardous substance reporting 

requirements imposed by other 

regulations and statutes. 

II. Releases Covered by This Notice 

A. Hazardous Substances Subject to this 

Notice 

Congress incorporated six lists of 

substances, identified primarily under 

other environmental statutes, in the 

definition of hazardous substances 

under section 101(14) of CERCLA. These 

lists are: 

(1) Substances designated pursuant to 

section 311 of the Clean Water Act 

(CWA); 

(2) Hazardous wastes under section 3001 

of the Solid Waste Disposal Act 

(commonly known as the Resource 

Conservation and Recovery Act or 

"RCRA"), but excluding wastes the 

regulation of which has been 

suspended by Congress; 

(3) Toxic pollutants listed under CWA 

section 307(a); 

(4) Hazardous air pollutants listed under 

section 112 of the Clean Air Act; 

(5) Imminently hazardous chemicals or 

mixtures for which EPA has taken 

action under section 7 of the Toxic 

Substances Control Act; and 

(6) Substances designated pursuant to 

section 102 of CERCLA. 

Radionuclides, the subject of this 

proposed rule, are considered hazardous 

substances under CERCLA because they 

were designated generically as 

hazardous air pollutants pursuant to 

section 112 of the Clean Air Act. Even 

though the source of their listing is the 

Clean Air Act, releases of radionuclides 

to all media are covered under section 

103 of CERCLA and the provisions of 

this rule. 

A radionuclide is a particular form 

(isotope) of an element which is 

unstable. To achieve a more stable 

configuration, the nucleus releases 

energy in the form of particles or 

electromagnetic radiation by a process 

of decay called radioactivity. Each 

radionuclide decays at a different rate 

and, as a result, a pound of each of two 

different radionuclides could represent 

significantly different levels of 

radioactivity. The principal health 

concern associated with a radionuclide 

release is carcinogenicity. There are 

approximately 1,800 different 

radionuclides and, because they are 

listed generically as a hazardous air 

pollutant under the Clean Air Act, all 

1,800 are considered CERCLA 

hazardous substances. Until adjusted by 

EPA under section 102(a) of CERCLA, 

all radionuclides have a statutory RQ of 

one pound. 

Uranyl acetate and uranyl nitrate, 

which are specifically listed as CERCLA 

hazardous substances because they are 

included under section 311 of the Clean 

Water Act, have a final adjusted RQ of 

100 pounds based on their chemical 

toxicity (51 FR 34534, September 29, 

1986). These compounds are composed 

of approximately 66 percent uranium, 

most generally uranium-238. Because 100 

pounds of uranium-238 is approximately 

0.015 curie, a proposed RQ based on 

radiological hazard could be higher than 

the final adjusted RQ based on chemical 

toxicity. Therefore, the final adjusted 

RQ for uranyl acetate and uranyl nitrate 

will remain 100 pounds if the RQ based 

on radiological hazard is greater than 

0.015 curie. 

B. Definition of Releases Subject to this 

Notice and Statutory Exemptions 

Congress defined the term "release" 

to include within its scope virtually all 

ways that substances may enter the 

environment: 
P.4 

8174 Federal Register / Vol. 52, No. 50 / Monday, March 16, 1987 /Propose d Rules 

"release" means any spilling, leaking, 

pumping, pouring, emitting, emptying, 

discharging, injecting, escaping, 

leaching, dumping, or disposing into the 

environment (including the 

abandonment or discarding of barrels, 

containers, and other closed receptacles 

containing any hazardous substance or 

pollutant or contaminant] (section 

101(22) as amended by section 101(c) of 

SARA). 

Four types of releases are specifically 

excluded from the definition of release 

in CERCLA section 101(22) and thus do 

not need to be reported under section 

103: 

(1) Releases which result in exposures to 

persons solely within a workplace for 

which claims against the employer or 

other persons are available; 

(2) Emissions from engine exhaust from 

a motor vehicle, rolling stock, aircraft, 

vessel, or pipeline pumping station 

engines; 

(3) Releases of source, byproduct, or 

special nuclear material4 from a 

nuclear incident subject to 

requirements of the Nuclear 

Regulatory Commission for financial 

protection under section 170 of the 

Atomic Energy Act;

 6 and 

(4) The normal applications of fertilizers. 

Radionuclide releases may be 

excluded from reporting requirements 

because they fall under any of these four 

provisions. For example, exposure of 

persons to radionuclide releases solely 

within a workplace and radionuclide 

releases resulting from the normal 

application of fertilizer containing 

radionuclides are both possible. The 

exclusion for radionuclides most likely 

to be of greatest importance, however, is 

for releases of source, byproduct, or 

special nuclear material from a nuclear 

incident. Nuclear reactors are the 

primary type of facility subject to the 

* Source material is defined as (1) natural 

uranium, thorium, or any combination thereof or (2) 

ores which contain 0.05 percent (by weight) of 

uranium or thorium (section ll(z) of the Atomic 

Energy Act, and Nuclear Regulatory Commission 

regulations in 10 CFR Part 40). Byproduct material is 

(1) any material made radioactive by exposure to 

radiation in the process of producing or using 

special nuclear material or (2) the wastes produced 

by the extraction or concentration of uranium or 

thorium from ore (section 11(e) of the Atomic 

Energy Act). Special nuclear material is defined as 

plutonium, or uranium enriched in the U-235 or U233 isotope (Atomic Energy Act section ll(aa)). All 

of these materials are licensed by the Nuclear 

Regulatory Commission and its Agreement States. 

* A release of source, byproduct, or special 

nuclear material from a processing site designated 

under sections 102(a)(1) or 302(a) of the Uranium 

Mill Tailings Radiation Control Act of 1978 is not a 

"release" for purposes of response actions under 

CERCLA, but is subject to the notification 

requirements of sections 103 (a) and (b) (see section 

101(22)) and liability under section 107. 

referenced section 170 of the Atomic 

Energy Act. Section 170 essentially 

requires certain licensees, as a condition 

of receiving a license, to have and 

maintain certain financial protection to 

cover public liability claims. 

In addition, there are three types of 

statutory exemptions from the 

notification requirements for releases of 

hazardous substances: 

(1) Federally permitted releases as 

defined in section 101(10), (section 

103(a)); 

(2) Application of pesticide products 

registered under the Federal 

Insecticide, Fungicide, and 

Rodenticide Act (FIFRA), (section 

103(e)); and 

(3) Certain releases of hazardous wastes 

which are required to be reported (or 

specifically exempted from a 

requirement for reporting) under the 

provisions of RCRA and which are 

reported to the National Response 

Center (section 103(f)(1)). 

While radionuclides conceivably 

could be present in low levels in some 

pesticides, the pesticide exemption is 

not significant for radionuclides. RCRA 

includes under its jurisdiction hazardous 

wastes containing naturally occurring 

and accelerator-produced radioactive 

material (NARM), and therefore, NARM 

releases reported under RCRA are 

exempt from CERCLA's reporting 

requirements. However, because RCRA 

does not cover source, byproduct, and 

special nuclear materials other than in 

mixtures with other hazardous wastes, 

and does not cover NARM releases 

other than in wastes, the RCRA 

reporting exemption does not apply to 

releases of these materials. 

The federally permitted release 

exemption is based on a lengthy 

statutory definition of "federally 

permitted release" in section 101(10) of 

- the Act that includes a reference to 

radioactive material: 

(10) "federally permitted release" 

means . . . (K) any release of source, special 

nuclear, or byproduct material, as those 

terms are defined in the Atomic Energy Act 

of 1954, in compliance with a legally 

enforceable license, permit, regulation, or 

order issued pursuant to the Atomic Energy 

Act of 1954. 

EPA plans to clarify the provisions of 

CERCLA section 101(10) in a future 

rulemaking. The preamble to that 

regulation will contain some general 

discussion of the federally permitted 

release exemption, including the 

provision referenced above, and a 

response to comments received on the 

May 25,1983 NPRM (48 FR 23552) which 

first discussed the federally permitted 

release exemptions. The following 

discussion is a more detailed 

explanation of the federally permitted 

release exemption as it applies to 

radionuclides. 

The Nuclear Regulatory Commission 

is responsible for many activities under 

the Atomic Energy Act. Licenses and 

permits may be issued by the Nuclear 

Regulatory Commission or by states to 

whom the authority to regulate 

radiation-related activities has been 

relinquished under an agreement with 

the Nuclear Regulatory Commission (i.e., 

Agreement States). Releases in 

compliance with licenses and permits 

issued by Agreement States under an 

agreement with the Nuclear Regulatory 

Commission are federally permitted 

releases. These licensing and permitting 

activities generally cover production, 

transfer, receipt, acquisition, use, 

delivery, and ownership by any person 

of source, special nuclear, or byproduct 

material. They include activities 

regulated in conformance with 

Environmental Radiation Protection 

Standards for Nuclear Powered 

Operations (40 CFR Part 190) and 

Environmental Standards for Uranium 

and Thorium Mill Tailings (40 CFR Part 

192) issued by EPA under the Atomic 

Energy Act. Facilities typically handling 

source materials include uranium mills 

and uranium processing facilities. 

Byproduct materials are used at a wide 

variety of facilities including 

radiopharmaceutical manufacturers, 

hospitals and clinics, sealed source 

manufacturers, and laboratories. Special 

nuclear material is primarily used as 

fuel for nuclear reactors and in the 

production of nuclear weapons. 

Regulations issued by the Nuclear 

Regulatory Commission specifically 

exempt certain facilities from the 

Commission's licensing, permitting, and 

regulatory requirements. Generally, 

these include facilities operated under 

Nuclear Regulatory Commission 

contracts; transport carriers of source, 

byproduct, or special nuclear material; 

those using "unimportant quantities" of 

source material; and certain production 

and utilization facilities operated by or 

for the Department of Defense (see 10 

CFR Parts 30, 40, 50 and 70). Because of 

their specific exemption from licensing, 

permitting, and regulatory requirements 

of the Commission, the Agency does not 

consider releases of radionuclides from 

these facilities to be "federally 

permitted." Therefore, such releases 

would not fall under the reporting 

exemption defined in section 101(10) of 

CERCLA. 

Administration of the Atomic Energy 

Act does not reside solely with the 

Nuclear Regulatory Commission. To the 
P.5 

Federal Register /Vol . 52, No. 50 / Monday, March 16, 1987 / Proposed Rules 8175 

extent releases from sources are in 

accordance with licenses, permits, 

orders, or regulations issued under the 

Atomic Energy Act through provisions 

not administered by the Commission, 

they also would be considered federally 

permitted releases. This would include 

orders issued under the Department of 

Energy's Atomic Energy Act authority. 

Other aspects of the federally 

permitted release exemption also could 

apply in the case of radionuclides. The 

exemption generally covers discharges 

and emissions in compliance with 

permits and control regulations under 

various environmental statutes. 

Radionuclides are, for example, 

regulated by EPA as a hazardous air 

pollutant under section 112 of the Clean 

Air Act. Any radionuclide release 

subject to a specific emission limitation 

or control regulation established under 

that section would be exempt as 

federally permitted, if the release^vere 

in compliance with the applicable Clean 

Air Act limit. If the release, however, 

exceeded the permitted level by an RQ 

or more, the release would be subject to 

the CERCLA reporting requirements. 

This issue will be clarified further in the 

separate rulemaking for the federally 

permitted release reporting exemption. 

In addition to the statutory 

exemptions from the RQ notification 

requirements for releases of hazardous 

substances, section 103(f)(2) of the Act 

provides a reduced reporting 

requirement for releases that are 

"continuous" and "stable in quantity 

and rate." Such releases only need to be 

reported annually or when there is a 

statistically significant increase in the 

quantity of the hazardous substance 

released. Therefore, releases of 

radionuclides that are "continuous" and 

"stable in quantity and rate" may 

qualify for this reduced reporting 

requirement. The Agency plans to 

clarify the language and the notification 

requirements for continuous releases in 

a future rulemaking. 

In summary, releases of radionuclides 

that do not fall within one of the four 

specifically-listed exclusions under 

CERCLA section 101(22) and do not fall 

under one of the three statutory 

exemptions under CERCLA section 103, 

would be subject to this Notice of 

Proposed Rulemaking. 

III. Duplicate Reporting/Regulatory 

Consistency 

Several federal agencies have existing 

requirements to report radionuclide 

releases, including the Nuclear 

Regulatory Commission and the 

Departments of Transportation and 

Energy. EPA may also require reporting 

under the Toxic Substances Control Act 

(TSCA). The relevant reporting 

requirements of each agency are briefly 

summarized in this section. 

The Nuclear Regulatory Commission 

controls the handling of source, 

byproduct, and special nuclear materials 

through an extensive licensing and 

regulatory program. This program 

includes several different requirements 

for responsible parties to report releases 

of radionuclides immediately in certain 

cases of material loss or where a release 

may have caused or threatens to cause 

certain dose or intake levels to 

individuals (see 10 CFR Parts 2a 30, 40, 

and 70). In addition to these 

requirements, the Commission has 

several other requirements to report . 

within a specified time after a release, 

but not immediately (e.g., within 24 

hours or within 30 days for releases 

involving potential for lower levels of 

exposure and lower radioactive 

concentrations). 

The Department of Transportation 

(DOT) is responsible for regulating 

safety in the transportation of all 

hazardous materials. Accordingly, DOT 

has promulgated the Hazardous 

Materials Regulations (49 CFR Parts 

171-177) to govern the transportation of 

hazardous materials, including 

radioactive materials, and the reporting 

of releases associated with transport. 

Reporting is required for each incident 

occurring during the course of 

transportation, including death, injury, 

property damage exceeding $50,000, or 

spillage or suspected contamination. 

DOT defines radioactive material as any 

material having a specific activity 

greater than 0.002 microcuries per gram. 

According to a Memorandum of 

Understanding (44 FR 38690, July 2,1979) 

between DOT and the Nuclear 

Regulatory Commission, DOT will 

promptly notify the Commission of any 

accidents, incidents, and instances of 

actual or suspected leakage involving 

radioactive material packages if such an 

event occurs in transit. DOT also has the 

responsibility of encouraging the nonAgreement States to impose incident 

reporting requirements for radioactive 

materials on shippers and receivers 

subject to the states' jurisdiction. 

The Department of Energy (DOE) 

plays two entirely different roles in the 

area of radionuclide releases. In the first 

role, there are many established 

requirements for DOE or its contractors 

and other members of the regulated 

community to report radionuclide 

releases immediately, generally to a 

DOE regional operation office, which 

may in turn report the release to DOE 

Headquarters. Many of these 

requirements are self-imposed and are 

spelled out in several different internal 

orders written under the authority of the 

Atomic Energy Act. Their purposes 

include environmental protection, 

safety, and health protection. In its 

second role, DOE, through the Federal 

Radiological Monitoring and 

Assessment Plan, provides expertise, 

guidance, and assistance in response to 

radiological hazards created by others. 

DOE is generally exempt from licensing 

by the Nuclear Regulatory Commission 

through the Atomic Energy Act, and is 

thus exempt from the Commission's 

reporting requirements discussed above. 

However, as a matter of policy, DOE 

requires reporting to external 

organizations to keep them apprised of 

important events at DOE facilities. 

Section 8(e) of the Toxic Substances 

Control Act (TSCA) also may require 

reporting where CERCLA does not. 

Pursuant to a Statement of 

Interpretation published March 16,1978 

(43 FR 11110), all emergency incidents of 

environmental contamination that 

present a "substantial risk of injury to 

health or the environment" must be 

reported to EPA under TSCA section 

8(e). Section 8(e) could require 

notification even where no CERCLA 

hazardous substances or RQs have been 

released. Persons subject to the 

notification requirement include both 

natural persons and business entities 

engaged in the manufacturing, 

processing, or commercial distribution 

of chemical substances or mixtures. No 

notification is required if the 

manufacturer, processor, or distributor 

knows that EPA has been informed of 

the risk presented by the incident. For 

radionuclide releases subject to 

CERCLA, a single notification to the 

National Response Center will satisfy 

both CERCLA and TSCA section 8(e) 

reporting requirements; the Agency will 

ensure that section 8(e) reports are 

passed to the proper authorities. 

CERCLA reporting requirements 

remain applicable and mandatory 

despite occasional overlap with the 

reporting requirements noted above 

under other statutes and authorities. At 

most, the duplication that exists may 

require that more than one telephone 

call concerning a release be made by the 

releaser and recorded by government 

agencies. The releaser's responsibility to 

notify other federal agencies is not 

affected by this proposed rule. EPA will 

be continuing its efforts to coordinate its 

regulation of radionuclides and 

cooperate with other federal agencies. 
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6176 Federal Register / Vol. 52, No. 50 / Monday, March 16, 1987 / Proposed Rules 

IV. Reportable Quantity Adjustments for 

Radionuclides 

A. Introduction and Previous RQ 

Adjustment Methodology 

The primary purpose of the CERCLA 

notification requirements is to ensure 

that releasers notify the government so 

that the need for a federal response can 

be evaluated and any necessary 

response undertaken in a timely fashion. 

- With this purpose in mind, EPA has to 

date promulgated two final rules, 

adjusting a total of 442 of the statutory 

RQs for CERCLA hazardous substances 

(50 FR 13458, April 4,1985; 51 FR 34534. 

September 29,1986). All of these RQ 

adjustments are based on specific 

scientific and technical criteria that 

relate to the potential toxicological and 

chemical effects of a hazardous 

substance. The adjusted RQs do not 

reflect a determination that a release of 

a substance will be hazardous at the RQ 

level and not hazardous below that 

level. EPA has not attempted to make 

'such a determination because the actual 

hazard will vary with the unique 

circumstances of the release, and 

extensive data and analysis would be 

necessary to determine the hazard 

presented by each substance in a 

number of possible circumstances. 

Instead, the RQs reflect the Agency's 

judgment of which releases should 

trigger mandatory notification to the 

federal government so that the 

government may assess to what extent, 

if any, a federal removal or remedial 

action may be necessary. 

The RQ adjustments made to date 

have been designed to: 

(1) Protect public health and the 

environment more effectively; 

(2) Improve EPA's ability to 

concentrate its attention and resources 

on the releases that potentially are most 

threatening to public health or welfare 

or the environment; and 

(3) Reduce the burdens of reporting on 

the regulated community. 

The selected strategy used for 

adjusting RQs in previous rulemakings 

begins with an evaluation of the 

intrinsic physical, chemical, and 

toxicological properties of each 

designated hazardous substance. The 

intrinsic properties examined—called 

"primary criteria"—are aquatic toxicity, 

mammalian toxicity (oral, dermal, and 

inhalation), ignitability, reactivity, 

chronic toxicity, and potential 

carcinogenicity. (For the purposes of this 

rule, chronic toxicity is defined as 

toxicity resulting from repeated or 

continuous exposure to either a single 

release or multiple releases of a 

hazardous substance.) 

The Agency generally ranks each 

intrinsic property on a five-tier scale, 

associating a specified range of values 

on each scale with a particular RQ 

value. Thus, each substance receives 

several tentative RQ values based on its 

particular properties. The lowest of all 

of the tentative RQs becomes the 

"primary criteria RQ" for that 

substance. 

After the primary criteria RQs are 

assigned, substances are further 

evaluated for their susceptibility to 

certain degradative processes. These 

natural degradative processes are 

biodegradation, hydrolysis, and 

photolysis, or "BHP." If the analysis 

indicates that a substance degrades 

relatively rapidly to a less harmful 

compound through one or more of these 

processes when it is released into the 

environment, the primary criteria RQ is 

raised one level. The single RQ assigned 

to each substance on the basis of the 

primary criteria and BHP becomes the 

adjusted RQ for that substance. 

For purposes of RQ adjustments using 

the primary criteria noted above under 

CERCLA, (other than potential 

carcinogenicity—see the separate NPRM 

published in today's Federal Register), 

EPA has adopted the five RQ levels of 1, 

10,100,1000, and 5000 pounds originally 

established pursuant to CWA section 

311 (see 40 CFR Part 117). The Agency 

adopted the CWA five-level system 

primarily because (1) it has been used 

successfully pursuant to the CWA, (2) 

the regulated community is already 

familiar with these five levels, and (3) it 

distinguishes the broad range of 

potential harm posed by CERCLA 

hazardous substances. 

Even though EPA will continue to use 

this established five-level system for 

most RQ adjustments, the Agency does 

not believe that it represents an 

appropriate approach for radionuclides 

in either the choice of levels or the unit 

of measurement (pounds). A one-pound 

RQ for radionuclides, the lowest 

currently available, would not trigger 

timely reporting or response for releases 

of many radionuclides. In many cases, 

releases of radionuclides that are 

several orders of magnitude smaller 

than one pound can represent a health 

and environmental threat that merits 

reporting to the National Response 

Center. A one-pound RQ also does not 

conform to accepted un-its for radiation 

protection. The commonly accepted 

units for radiation protection are (1) rem 

(or sieverts) which measure the amount 

of biological damage resulting from 

exposure to ionizing radiation, and (2) 

curies (or becquerels) which measure 

the rate of radioactive decay and thus 

the rate at which radiation is given off 

by a substance (activity level). Finally, a 

one-pound RQ level would differ 

significantly from reporting 

requirements for radionuclides under 

other regulations issued by EPA and 

other agencies. For these reasons, EPA 

is proposing a different approach for 

radionuclides (see discussion of the 

selected option in Section IV.B. of this 

preamble). 

Section 102(a) of CERCLA authorizes, 

and the legislative history encourages, 

the Administrator to set a single RQ for 

any hazardous substance, regardless of 

the medium into which that substance is 

released. In order to develop simple and 

practical notification provisions, the 

Agency has to date established a single 

RQ for each hazardous substance. If 

multiple RQs which vary in accordance 

with the environmental media into 

which the substance is released were 

established, it would be more difficult 

for the regulated community to comply 

with the reporting requirements. 

Because releases often occur into more 

than one medium, the releaser, under a . 

multi-RQ format, would be uncertain 

which RQ would apply. EPA is 

proposing, therefore, to continue the 

single-RQ approach for each 

radionuclide. 

B. Options Considered and 

Radionuclide RQ Methodology 

EPA formed an interagency work 

group consisting of representatives of 

the Nuclear Regulatory Commission, the 

U.S. Coast Guard, the U.S. Departments 

of Energy and Transportation, and 

several offices within EPA to discuss 

issues and alternative approaches for 

adjusting the radionuclide RQ. The work 

group evaluated a number of options 

before selecting the approach chosen in 

this proposal. The following principal 

options were rejected: 

Option 1: Leaving the radionuclide RQ 

at one pound 

The Agency considered establishing 

an adjusted RQ for radionuclides equal 

to the statutory RQ of one pound. As 

discussed above in section IV.A. of this 

preamble, a one-pound RQ level would 

allow numerous potentially significant 

releases of many radionuclides to go 

unreported. Many such releases well 

below one pound could represent a 

potential health and environmental 

threat. In addition, a one-pound RQ does 

not conform to commonly accepted units 

or accepted levels for radiation 

protection, and it would differ 

significantly from reporting 

requirements under other radionuclide 

regulations issued by EPA and other 

agencies. Finally, one pound translates 
P.7 

Federal Register / Vol. 52, No. 50 / Monday, March 18, 1987 / Proposed Rules 8177 

into a different amount of radioactivity; 

and thus a different hazard level, for 

each radionuclide. 

Option 2: Establishing a dose-equivalent 

level as the radionuclide RQ 

A dose-equivalent level, in units of 

rem or sieverts, is a measure of the 

amount of biological damage resulting 

from exposure to ionizing radiation. 

Dose-equivalent limits are frequently 

established in groups, such as 25 

millirem to the whole body and 75 

millirem to the thyroid gland. 

Radionuclides could be considered as a 

class with a dose-equivalent level, or a 

set of dose-equivalent levels (e.g., whole 

body and thyroid gland separately) 

could be assigned to the entire class. 

Estimating a dose-equivalent level can 

he quite complicated. The dose 

equivalent may vary substantially for 

different release circumstances, even if 

the same quantity of radionuclide is 

released. In addition, estimating doseequivalent levels requires making 

numerous assumptions, and the level of 

dose may vary drastically under 

different assumptions. Because of all the 

judgments and assumptions required to 

estimate dose equivalents, the estimated 

dose equivalent for two different 

releases with the same level of activity 

of the same radionuclide may vary 

drastically under different assumptions. 

This potential variability makes it 

difficult to (1) assure that the 

government will be notified of all 

radionuclide releases that it deems 

necessary; and (2) enforce an RQ in 

dose-equivalent units. 

A dose-equivalent level is also more 

difficult to estimate quickly during an 

actual release event than an activity 

level. The Agency determined that an 

RQ in terms of dose equivalent (rem) 

would leave a significant amount of 

judgment to the person in charge of the 

facility or vessel. The person in charge 

would be required to estimate the 

quantity released, the potential routes of 

exposure, the period of exposure, and 

the most vulnerable organ of the body 

potentially affected by the release. In 

essence, if the RQ were to be 

established in units of rem, the person in 

charge of the vessel or facility would be 

placed in a position of determining 

whether the release posed a threat to 

public health or welfare or the 

environment. CERCLA establishes that 

role for the federal government, not for 

the person in charge of the vessel or 

facility. 

Option 3: Considering radionuclides as a 

class with a single activity level 

Activity level is measured in units of 

curies or becouerels, and is an accepted 

unit of radiation measurement. The 

Agency considered establishing one RQ 

in units of curies for the entire class of 

radionuclides. 

This option has the advantage of 

being simple, and curies are relatively 

easy to measure quickly during a 

release. It does not, however, account 

for the varying degrees of hazard posed 

by the same activity level of different 

radionuclides. The same level of 

radioactivity (i.e., the same number of 

curies) of two different radionuclides 

may yield two entirely different dose 

levels. Therefore, while simplicity in 

reporting must be sought, it should not 

be accomplished by glossing over 

substantial differences among individual 

radionuclides. It would be extremely 

difficult to derive an RQ that is a single 

level of activity and that would provide 

timely reporting of the most hazardous 

radionuclides while not requiring too 

many reports for others. A single level of 

activity could, however, be an 

appropriate RQ if it were only applied to 

a group of similar radionuclides (see 

Option 4 below). 

Option 4: Grouping radionuclides into 

categories with an activity level 

assigned to each of the separate 

categories 

Radionuclides may be separated into 

various groups in such a way that a 

single level of activity may be an 

appropriate RQ for all the radionuclides 

within a given group. One RQ, which 

would assure timely reporting for 

releases of the most hazardous 

radionuclide(s), could then be assigned 

to the overall group. For example, 

radionuclides could be grouped into 

"half-life categories" with progressively 

higher RQs for those categories having 

shorter half lives. Another example is to 

separate radionuclides into groups of 

alpha, beta, and gamma emitters. The 

RQs for non-radioactive substances 

have been established in a similar 

fashion, with different RQs for different 

groups of chemicals that exhibit similar 

chemical properties. 

The Agency chose not to adopt this 

option with either of the above methods 

of categorizing radionuclides. The 

Agency believes that radionuclides 

grouped into "half-life categories" with 

progressively higher RQs for those 

categories having shorter half lives may 

not be protective of human health and 

the environment. For radionuclide 

releases which deliver the same total 

radiation dose, radionuclides with 

shorter half lives will emit radiation at a 

higher rate. Therefore, for radionuclides 

with relatively short half lives, the 

federal government may wish to receive 

notification of relatively small releases 

of such radionuclides to determine 

whether a response action is necessary, 

even if the radiation danger is relatively 

short lived. With regard to categorizing 

radionuclides on the basis of whether 

they are primarily alpha, beta, or gamma 

emitters, the actual threat to human 

health is less dependent on the nature of 

the emission than on the route of 

exposure. In addition, there are 

numerous radionuclides that fall into 

each of these categories, and a single 

activity-level RQ for the group may not 

be appropriate for all the individual 

group members. 

The Selected Approach.—The EPApreferred option begins with a decision 

to establish an RQ in terms of activity 

(measured in units of curies) for 

individual radionuclides. The primary 

advantages of this strategy are: 

• A level of radioactivity generally is 

much easier to measure than dose 

equivalent, would be easier to confirm, 

and would provide more timely 

reporting than an RQ in terms of dose 

equivalent. 

• Establishing RQs for radionuclides 

individually would allow consideration 

of individual radionuclide 

characteristics. 

This regulation proposes to revise 

RQs for all of the approximately 1,800 

currently known radionuclides. A large 

majority of these, however, are listed as 

a generic class with a single RQ. 

To develop individual RQs in units of 

curies, the Agency relied heavily on the 

health data and human intake limits 

published by the International 

Commission on Radiation Protection 

(ICRP), particularly as reflected in its 

Publication 30 (Pergamon 1982). Data 

were available for 757 radionuclides and 

so analysis of individual radionuclides 

was limited to this universe. The 

Commission does not claim that this list 

is comprehensive, but it does represent 

all radionuclides for which data needed 

by EPA to evaluate the effects of a 

radionuclide release are available. 

Thus, EPA is today proposing to 

establish individual RQs for 757 

radionuclides. Because of the 

inadequacy of available data for all 

other radionuclides, they are proposed 

to be treated as a generic class with a 

single RQ for the entire class. 

Radionuclide RQ Adjustment 

Methodology.—The development of the 

individual proposed RQs begins with the 

Annual Limitations of Intake (ALIs) 

developed by the International 

Commission on Radiation Protection. 

The ALIs: 

are the annual intakes of given radionuclides 

by 'Reference Man' which would result in 

either (1) a committed effective dose 
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81781 Federal Register / Vol. 52, No. 50 / Monday. March 16. 1987 / Proposed Rules 

equivalent • pf 5 rem to the whole body 

(stochastic ALI), or (2) a committed dose 

equivalent' of 50 rem to any organ or tissue 

(non-stochastic AU). 

The ICRP has presented ALIs for both 

oral ingestion and inhalation. The ALIs, 

which are in units of microcuries, are 

considered to produce harm comparable 

to that of receiving a uniform whole 

body dose-equivalent radiation 

exposure of 5 rem. It is important to 

clarify that the ALIs represent quantities, 

of radionuclides taken into the body, not 

quantities released to the environment. 

These curie levels were adjusted by 

EPA to reflect (1) the difference between 

intake levels and release levels, and (2) 

a lower dose equivalent of 500 millirem 

(0.5 rem), a more protective limitation. 

Federal Radiation Protection Guidance 

recommends 500 millirem as an upper 

bound on exposure to individual 

members of the general public. The 

Agency currently is considering making 

a recommendation to lower this limit. In 

anticipation of this action, the Agency is 

considering two alternative bases for 

the calculation of radionuclide RQs. 

These alternatives range between 25 

millirem per year and 100 millirem per 

year dose equivalent. A 25 millirem per 

year dose equivalent would result in 

RQs of V20 the value of RQs in today's 

notice. A 100 millirem per year dose 

equivalent would result in RQs of Vs the 

value of RQs in today's notice. The 25 

millirem limit reflects the standards in 

existing regulations promulgated by 

EPA. For example, rules which apply to 

high-level radioactive waste disposal (46 

CFR Part 191) limit exposure to the 

general public to 25 millirem per year. 

National Emission Standards for 

Hazardous Air Pollutants (NESHAP) set 

under the Clean Air Act (40 CFR Part 61) 

also limit exposure to the general public 

to 25 millirem per year. The higher 

endpoint of the range, 100 millirem, is 

believed to be a reasonable option for 

the revision of the Federal Radiation 

Protection Guidance. 

For purposes of this rulemaking, the 

Agency used conservative assumptions 

regarding different releases to air and 

water, and analyzed exposure through 

inhalation, ingestion, and direct 

exposure. The Agency then estimated 

the smallest number of curies of a 

radionuclide which, if released to the 

environment, would be likely to result in 

a person being exposed to a dose 

equivalent of 500 millirem. 

In developing proposed RQs, the 

Agency does not account for radioactive 

decay explicitly in its models. This is a 

conservative approach resulting in 

lower RQs for some short-lived 

radionuclides because some short-lived 

radionuclides decay prior to causing a 

dose equivalent of 500 millirem. The 

Agency took this conservative approach 

to simplify the analysis and because few 

radionuclide releases are expected to be 

affected by this approach. EPA seeks 

comment on the appropriateness of 

incorporating explicitly radiological 

decay in the models developed for the 

exposure pathways discussed below. If 

radionuclide half lives are incorporated 

explicitly into the model calculations, 

the RQs for some short-lived 

radionuclides would increase. 

Separate equations were derived to 

adjust the ALIs to determine release 

values in curies for both the inhalation 

and ingestion pathways. A third set of 

equations was derived to develop ' 

release values on the basis of direct 

exposure to a radionuclide release. All 

of these equations are discussed briefly 

below and in more detail in the 

Technical Background Document to 

Support Proposed Rulemaking Pursuant 

to Section 102 of CERCLA: 

Radionuclides (hereinafter Technical 

Background Document), available for 

inspection at Room LG—100 U.S. 

Environmental Protection Agency, 401 M 

Street, SW, Washington, DC 20460. As 

noted earlier, use of an activity level in 

curies rather than a dose equivalent was 

selected because it is easier to measure 

and confirm, and would provide more 

timely reporting than an RQ in terms of 

dose equivalent. 

inhalation.—The inhalation equation 

derives a Release Value for each 

radionuclide. Release Values are in 

units of curies and represent the activity 

level of each radionuclide which, if 

released under conservative 

circumstances, could result in an 

exposed individual receiving a dose 

equivalent of 500 millirem (0.5 remj. The 

Release Values are derived by dividing 

the ALI for inhalation presented in the 

ICRP Publication 30 by the product of 

several factors: 

Inhalation 

Release Value 

AU 

10(R)(X/Q)(BR)(1X106) 

0

 The total whole body dose equivalent resulting 

from intakes of radionuclides in one year 

' The total dose equivalent averaged throughout a 

tissue in the 50 years after intake of a radionuclide 

into the body. 

Where: 

AU=Annual limitations of intake for 

inhalation (microcuries); 

10=Conversion factor between 5 rem and 500 

millirem; 

R=Release Fraction; 

X/Q=Atmospheric Relative Concentration 

Value; 

BR—Breathing Rate; and 

1X106=Conversion factor between 

microcuries and curies. 

For the ALI, previously described, 

where more than one inhalation ALI is 

given by ICRP for a particular 

radionuclide, the lowest one was used. 

This approach assures that the possible 

release of the most hazardous chemical 

form is takerrihto consideration. 

The release fraction describes the 

portion of radioactive materials that 

could become airborne and be of 

respirable size (10 microns in diameter 

or less). 

The atmospheric relative 

concentration value corresponds to a 

ground-level relative concentration 30 

meters downwind from a ground-level 

release under stable meteorological 

conditions. Thirty meters was chosen 

because cordons around a release pf a 

chemical hazardous substance at a 

transportation incident are generally 30 

meters in radius. At fixed facilities, the 

distance to unrestricted areas is likely to 

be greater than 30 meters; therefore 30 

meters will result in a conservative 

estimate for exposure. For restricted 

areas at fixed facilities, 30 meters would 

be a reasonable cordoned-off zone. A 

ground-level release under stable (Class 

D) meteorological conditions leads to 

higher ground-level concentrations than 

above-ground releases in more turbulent 

conditions, and thus a lower, more 

protective RQ. 

The breathing rate of "Reference 

Man" is taken to be 2.3 X 107 cubic 

centimeters per day. The Agency 

requests comments and data pertaining 

to the assumptions underlying the ; 

inhalation exposure model. 

Ingestion.—The ingestion equation 

used for RQ development is based on a 

release of a radionuclide to ground , 

water using an advection-dispersiori 

ground-water model, combined with 

conservative estimates for such 

parameters as ground-water flow 

velocities and transverse and 

longitudinal dispersion. The resulting 

equation, like the one for inhalation, 

derives a Release Value by dividing the 

ALI for ingestion by the product of 

several factors, here an assumed 

dilution factor, contact time, and water 

consumption rate, as well as numerical 

factors. 

Radionuclides can be ingested through 

the consumption of contaminated 

foodstuffs or contaminated drinking 

water. The common pathway for 
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Federal Register / Vol., 52, No. 50 / Monday, March 16, 1987 / Proposed Rules 8179 

radionuclides to reach the food chain is 

following an atmospheric radioactive 

release, e.g., in the release from the 

Chernobyl nuclear power plant many 

European countries had great concern 

regarding the safety of food cropsand 

milk. The Agency evaluated each of the 

757 radionuclides for which the ICRP 

developed ALIs and calculated Release 

Values for two ingestion exposure 

routes: food crop and drinking water. 

For the majority of radionuclides, the 

drinking water exposure route resulted 

inrlower.Release Values (i.e., was a 

more critical route of exp6sUre],-Eurthert 

for the radionuclides for which the food 

crop pathway produced lower Release 

Values, the Agency determined that in 

the vast majority of cases either 

inhalation or direct exposure was even 

more critical than food crop ingestion. 

Therefore, the Agency has chosen to 

proceed with development of a Release 

Value for ingestion based on 

consumption of contaminated drinking 

water. In addition, to be most protective, 

a ground-water exposure route was 

selected over surface water exposure. 

Based on our modeling assumptions, a 

release of radionuclides into a river or 

lake would likely result in larger dilution 

factors than a release to an aquifer and 

subsequently into a drinking water well. 

This large dilution factor would result in 

lower concentrations of radionuclides in 

the drinking water and lower levels of.. • 

radioactive contamination. The 

Technical Background Document has 

further detail on the food crop, ground 

water, and surface water exposure 

routes. The Agency requests comments 

and data pertaining to all exposure 

scenarios. 

The equation which EPA has adopted 

for the calculation of Release Values 

based on consumption of contaminated 

ground water is: 

Ingestion 

Release Value 

ALI 

10(DF)(CT)(WC)(1X109) 

where: 

AU=Lowest ingestion ALI given in the ICRP 

Publication 30; : 

10=Conversion factor between 5 rem and 500' 

millirem; '; ' 

DF=Dilution Factor (l/lite'r); ' ;: ; 

CT=Contact time (days); 

WC=Water consumption of "Reference . 

Man" (2 liters/day); and .. . 

1X 10s = Conversion factor between i . 

microcuries and curies. 

The maximum concentration in a 

plume 30 meters downgradient from a • 

point source release is calculated using 

ground-water advection-dispersion 

modeling equations which take into 

account sorption of the radionuclides in 

the aquifer. This maximum 

concentration is reflected in the Dilution 

Factor (DF). Thirty meters is chosen for 

consistency with the atmospheric model. 

Contact time, calculated using the 

advection-dispersion ground-water 

model, is the total time a contaminant 

plume will be in contact with a well 

located 30 meters (in this case) from the 

source. Contact time will vary by 

radionuclide and will be related to the 

sorption coefficient discussed above. 

The daily'water consumption estimate Is -

assumed by the ICRP to be 2 liters and 

is used here. 

Direct Exposure.—An equation with 

the same parameters—the quantity of 

radiation intercepted by "Reference 

Man" (ICRP Publication 23, Pergamon, 

1975) at a distance of 30 meters from a 

release and limiting the exposure to 500 

millirem—also was developed to 

calculate a value for a third route of 

exposure, direct exposure to a point 

source release of a radionuclide. The 

direct exposure Release Values 

represent the amount of radionuclide, in 

curies, necessary to provide a gamma 

ray dose of 500 millirad, the same as a 

dose equivalent of 500 millirem, to an 

individual 30 meters from a point source 

. release of radioactive material. Gamma 

rays alone are considered in this 

equation because the mean free path of 

alpha and beta particles with energies 

. lower than 10 MeV is less than 30 ' 

meters. The Direct Exposure Release 

Value equation is presented below: 

Direct Exposure 

Release Value ~~ 

• where: 

(6.41X10-")(Dn)(S2) 

(E.)(uJ(T)(exp(-u„S)) 

Dn=Dose equivalent (0.5 rem); 

S=Distance from the release (30 m); 

Ei <= Summation of the product of the gamma 

• ray energies (MeV) and the gamma ray 

fractions for each radionuclide; 

u«=Linear absorption coefficient for gamma 

. rays in air (cm"1); 

T=Duration of exposure (24 hours); and 

exp(-u^S)=Atmospheric attenuation from the 

• point of release to the receptor. • 

The factor 6.41 x 10"5 is a constant 

which relates gamma ray energy to 

exposure, and is discussed in more 

detail in:the Technical Background

 ; 

Document. The Agency requests , 

comments on this exposure scenario. 

The Agency is also considering an 

alternative method of calculating direct 

exposure Release Values, using specific 

gamma ray constants rather than the 

direct exposure Release Value equation 

discussed above. The gamma ray 

constants are derived empirically and 

are available only for a subset of 

radionuclides. The Agency requests 

comment on the appropriateness of 

using the gamma ray constants 

whenever available, and using the 

equation discussed above for the 

. calculation of Release Values for 

radionuclides when the constants are 

not available. 

A separate direct exposure equation 

was developed for submersion in a 

radioactive cloud pf rioble gas because 

submersion in a radioactive cloud 

results in an integrated dose from all 

directions at varying distances from the 

body, unlike direct exposure to a point 

source. Ingestion and-inhalation are not 

significant exposure pathways for noble 

gases as a result of their inertness, and 

ALIs for ingestion and inhalation are not' 

presented by the ICRP for most noble 

gases. 

The direct exposure Release Values 

for submersion in a radioactive cloud of 

noble gas are derived for argon, krypton, 

and xenon through the following 

equation: 

Direct Exposure Release. _ . 

Value 

83(DAq(T) 

lOtX/QHlXlO6) 

where: 

DAC=Derived Airborne Concentration 

(microcuries/cm3); 

T—Duration of exposure (1 day);. 

10=Conversion factor between 5 rem and 500 

millirem; 

X/Q=Atmospheric Relative Concentration 

Value at 30meters (8.4X10'"day/cm3); 

and 

1X106=Conversion factor between 

microcuries and curies. 

The. DAC value specifies the airborne 

concentratipn that would result in a 5 

rem whole body dose equivalent for a 

2000 hour exposure period. To adjust the 

:

 airborne, concentration from a 2000 hour 

exposure period to a 24 hour exposure < 

period, we multiply the DAC value by 83 

(2000 hours-•-24 hours). X/Q is the . 

; ground-level concentration value 30 

meters from the release point. The 

Agency requests comments and data on 

this exposure scenario.. 

Establishing the RQ.—For each 

radionuclide, therefore, three values are 
P.10 

8180 Federal Register / Vol. 52, No. 50 / Monday, March 16, 1987 / Proposed Rules 

derived. The Agency has selected the 

lowest of the three values for each 

specific radionuclide with the intent of 

choosing an RQ that is the most 

protective of human health and the 

environment. This is Comparable to the 

methodolpgy used to adjust chemical 

RQs in previous rulemakings which 

evaluates six intrinsic properties or 

"primary criteria" for each hazardous 

substance. After assigning tentative RQs 

for the various properties, the lowest 

tentative RQ becomes the "primary 

criteria RQ" for that substance. A 

detailed explanation of the methodology 

used to derive proposed radionuclide 

RQs can be found in Chapter 4 of the 

Technical Background Document. 

To-simplify administration and 

implementation of RQ reporting for the 

757 separate radionuclides, EPA has 

decided to place each radionuclide in 

one of seven groups, each group 

assigned a single specific proposed RQ. 

The Technical Background Document 

discusses this assignment of RQs in 

greater detail. The proposed RQs for the 

seven radionuclide groups are as 

follows: 

Proposed 

adjusted 

HQ(in 

curies) 

0.001 

0.01 

0.1 

1 

10 

100 

1000 

Lowest release 

value range (in 

curies) 

0.001-0.0099 

0.01-0.099 

0.1-0.99 

1-9.99 

10-99.99 

100-999.99 

1000 and greater 

Number ot 

radionuclides 

6 (0.8%) 

25 (3.3%) 

24 (3.2%) 

35 (4.6%) 

342 (45.2%) 

236 (31.2%) 

89(11.8%) 

All known radionuclides not listed by 

the ICRP have been assigned a proposed 

final RQ of one curie. Available 

information on these radionuclides is 

insufficient for any meaningful analysis 

by the Agency of the appropriateness of 

any particular RQ for individual 

radionuclides in this group or the group 

as a whole. A proposed RQ of one curie 

was selected because it is the middle 

RQ category, and the majority pf 

radionuclides (93 percent) examined 

individually have proposed RQs at least 

at this level. The Agency expects that 

releases of an RQ or more of any of 

these radionuclides would be rare. 

Therefore, EPA is proposing a group RQ 

that it believes is sufficiently protective 

of public health and welfare and the 

environment without posing an 

unreasonable burden on the regulated 

community. 

Assignment of the individually 

calculated RQ to one of the seven 

groups and placement of other 

radionuclides in the generic RQ group 

should not be interpreted to mean that 

all radionuclides in any given group 

represent the same threat or danger to 

public health and welfare and the 

environment. Two or more radionuclides 

with the same proposed RQ do not 

reflect a determination that a release of 

one will be as hazardous as the release 

of another, or even that the release of 

one will be hazardous at the proposed 

RQ level and not hazardous below that 

level. The actual hazard will vary with 

the unique circumstances of the release, 

and extensive scientific data and 

analysis would be necessary to 

determine the hazard presented by each 

substance under a number of possible 

circumstances. The proposed RQs are 

designed to be a trigger for notification 

and reflect the Agency's judgment that 

the federal government should be 

notified of certain releases to which a 

federal response might be necessary. 

The RQs represent a determination only 

of possible or potential harm, not that 

releases of a particular amount of a 

hazardous substance necessarily will be 

harmful to public health or welfare or 

the environment. 

C. Alternative Approaches 

In addition to the method and 

assumptions used to develop the RQ 

adjustments proposed today, EPA is 

soliciting comments on the underlying 

assumptions discussed above and also 

is considering other methodologies for 

developing RQs for radionuclides. These 

approaches are described below. EPA 

requests public comment on whether 

one of these approaches or a related 

approach would be more appropriate for 

establishing the RQ adjustments in the 

final rule than that used for today's 

proposal. 

1. Use Similar Pathway-Based 

Methodology, but with Different 

Assumptions 

In the method used to develop today's 

proposed RQs, EPA has chosen to model 

the pathways that could be taken by 

released radionuclides, using three 

exposure scenarios for each of the 757 

radionuclides for which intake limits are 

available. Under this approach, the 

assumptions governing exposure 

scenarios are critical to the outcome. 

While EPA believes the scenarios used 

were reasonable, there could be 

circumstances where an actual release 

results in a dose equivalent higher than 

500 millirem. Therefore, the Agency is 

considering the use of different 

assumptions, which could result in 

different RQs for many radionuclides. 

EPA recognizes that, when using 

modeling techniques such as the three 

selected exposure scenarios, there will 

be instances in which the facts of a 

particular situation may vary from the 

assumptions relied upon in the model. 

For example, the three exposure 

scenarios incorporate the assumption 

that the distance between the release 

and the point of exposure is 30 meters. It 

is possible, however, that an exposed 

individual may be located nearer to the 

release. A different assumed distance 

would result in different calculated 

Release Values for these pathways, and 

different resulting RQs in some«ases. 

EPA is considering and soliciting 

comments on whether a shorter distance 

(perhaps as low as one meter) may be 

more appropriate. 

EPA also is considering whether other 

assumptions used in the three exposure 

scenarios are sufficiently protective of 

public health, such as the period for 

direct exposure. Exposure to an 

unreported release could continue 

longer than the 24-hour period used in 

the scenario. Therefore, an assumption 

of six months or one year of exposure 

may be more appropriate than a 24-hour 

exposure period. The Agency solicits 

public comment and data on this general 

issue and suggestions for the most 

appropriate choices for exposure 

scenarios for the development of RQs. 

2. Establish RQs as a Multiple of the 

ALIs 

EPA also is soliciting comment on 

alternative methodologies for 

calculating RQs. For inhalation and 

ingestion, one method under 

consideration is to multiply the lowest 

ALI for each radionuclide by a selected 

numerical constant. EPA is considering 

numerical constants such as 5. For the 

very worst case of exposure, i.e., 

ingestion or inhalation of 100 percent of 

a release by a single individual, an 

amount of 5 times the ALI would result 

in a radiation dose of 25 rem, a dose at 

which measurable immediate effects are 

first observed. Because the numerical 

constant of 5 is related to an assumption 

that may be overly conservative, EPA 

also is considering higher numerical 

constants which might be justified by 

considering exposures less conservative 

than the very worst case. EPA also is 

considering lower numerical constants 

tp reflect a lower acceptable dose 

equivalent. EPA requests comment on 

this approach, on a suitable choice for 

the numerical constant, and on a 

rationale for the numerical constant 

chosen. 
P.11 

Federal Register / Vol. 52, No. 50 / Monday, March 16, 1987 / Proposed Rules 8181 

D. Reporting Requirements for Mixtures 

of Radionuclides 

Some releases of radioactive 

substances are likely to consist of 

mixtures of radionuclides. These 

releases will be one of two general 

types: mixtures of known composition or 

mixtures of unknown composition. 

Mixtures of Known Composition 

The Agency is proposing the following 

method for evaluating mixtures of 

known composition. This method is 

different from the mixture rule for other 

hazardous substances established under 

the Clean Water Act (see 50 FR 13456, 

April 4,1985). 

Reporting requirements for releases 

involving mixtures of known 

composition can be obtained directly 

from the proposed RQs for individual 

constituents of the mixture. If the 

identity and quantity (in curies) of each 

radionuclide involved in a release event 

is known, the decision whether to report 

a release must be made in the following 

manner: for each radionuclide in the 

mixture, determine the ratio between the 

quantity released in curies and the RQ 

for the radionuclide. If the sum of the 

ratios for all radionuclides is less than 1, 

the release need not be reported. If the 

sum is equal to or greater than 1, the 

release must be reported to the National 

Response Center. 

For example, if radionuclides "a", "b", 

and "c" are present in quantities Qa, 

Qb, and Qc curies in a mixture, and if 

the proposed RQs are RQa, RQb, and 

RQc, respectively, then the quantity 

released for the mixture does not equal 

or exceed the proposed RQ and the 

release need not be reported to the 

National Response Center if (Qa/ 

RQa + Qb/RQb+Qc/RQc) is less than 1. 

This convention for handling releases of 

radionuclide mixtures is recommended 

by the ICRP and presently is used in 

existing federal regulations (e.g., 10 CFR 

Part 20). 

Mixtures of Unknown Composition 

Reporting requirements for mixtures, 

where either the amount or identity of 

the radionuclides in the mixture are 

unknown, cannot be based on the 

determination of quantities released. 

There are three possibilities: (1) The 

identity of the radionuclides involved is 

known, but the amounts released of 

each is unknown, (2) the identity of the 

radionuclides (or one of the 

radionuclides) in the mixture is 

unknown, but the amount released is 

known in total curies per unit volume or 

weight, or (3) the identity of the 

radionuclides involved is unknown and 

the amount of radionuclides released in 

the mixture is unknown. For these cases, 

EPA proposes that the decision to report 

a release be made as follows: 

(1) Identity known, but amount 

unknown. 

If the identity of each radionuclide in the 

mixture is known but the amount of one 

or more of the radionuclides is 

unknown, the RQ for the mixture shall 

be the lowest RQ of any radionuclide in 

the mixture. 

This method fpr determining the RQ of 

a mixture assures a report to the 

National Response Center if the total 

number of curies involved in a release is 

equal to or greater than the RQ in curies 

of the substance with the lowest 

proposed RQ in the mixture. 

(2) and (3) Identity of radionuclide(s) 

in the release is unknown. 

If the identity of a radionuclide in a 

release is unknown or if the identity of 

one or more radionuclides in the release 

of a mixture of radionuclides is 

unknown, the release must be reported 

to the National Response Center if the 

total release is equal to or greater than 1 

curie, or if the total release is equal to or 

greater than the lowest RQ of any 

known radionuclide in the mixture, 

whichever is lower. 

. Establishing an RQ of 1 curie for a 

release in which the identity of the 

radionuclide or radionuclides involved 

is unknown is consistent with the 1 curie 

RQ for the class of radionuclides for 

which insufficient data exist to establish 

individual RQs. This mixture rule 

requires reporting if the release equals 

or exceeds 1 curie, or, if some 

component of the mixture is known and 

its RQ is less than 1 curie, then the total 

release must be reported if it equals or 

exceeds the RQ of the known 

component. The Agency also is 

considering establishing an RQ for 

unknown mixtures at 0.001 curie, the 

lowest proposed RQ level. This is based 

upon the assumption that the release 

may be of the most dangerous 

radionuclide. This approach assures that 

the government has the opportunity to 

evaluate all uncertain but potentially 

dangerous radionuclide releases and 

respond, if necessary. 

Common Radionuclide Mixtures 

The Agency today also is proposing to 

establish RQs for two common 

radionuclide mixtures: radium-226 in 

equilibrium with its daughters, and 

natural uranium. The Agency is 

proposing these RQs for the 

convenience of persons frequently 

handling these mixtures. The RQs are 

developed directly from the mixture rule 

discussed above. 

Radium-226 has a half life of 1,600 

years, substantially greater than the half 

lives of its daughters. After a sufficient 

period of time, however, a state of 

equilibrium is established in the 

mixture, such that the quantity of 

activity present for each daughter 

product and the parent radium is equal. 

When radium and its daughters reach 

this state pf equilibrium, the RQ of the 

mixture is 0.43 curie, in contrast to the 1 

curie RQ for radium-226.. 

Natural uranium is composed of the 

isotopes uranium-238 (99.27 percent by 

weight), uranium-234 (0.0057 percent by 

weight), and uranium-235 (0.72 percent 

by weight). Because we know the 

composition by weight of natural 

uranium, we can derive the activity 

levels of each of its components. The 

proposed RQ for natural uranium, 

derived through the mixture rule, is 0.1 

curie, the same as the RQ for the 3 

isotopes in the mixture. 

Mixed fission products are also 

recognized by the Agency as an 

important and common radionuclide 

mixture. However, the Agency today is 

proposing RQs only for the individual 

radionuclide components within mixed 

fission products because an RQ for this 

mixture would have to be timedependent. That is, at different times, 

the concentration of the different 

components of this mixture will be 

different. In addition, the composition of 

mixed fission products depends upon 

the type of reactor which produces the 

mixed fission product. Thus, different 

RQs would need to be presented for 

different mixed fission products. 

E. Other Issues 

Estimating the Effects of Radiation 

The harmful effects of radiation on 

humans have been the focus of most of 

the research efforts concerning radiation 

exposure in the past. EPA, of course, 

also is concerned with the broader 

problem of potentially deleterious 

effects to the environment, as well as to 

humans. In adjusting radionuclide RQs, 

the Agency's goal is to ensure, to the 

extent possible, ample protection for the 

most sensitive species of flora and 

fauna. To identify the most sensitive 

species, the Agency reviewed the 

existing literature and determined that 

present information indicates that RQs 

chosen to provide adequate protection 

of the human species would be 

sufficiently protective of the 

environment as well. The Agency has 

determined, therefore, that RQ 

adjustments developed with the goal of 

protecting public health also will 

adequately protect the environment. 
8182 Federal Register / Vol. 52. No. 50 / Monday, March 16. 1987 / Proposed Rules 

EPA solicits public comments on this 

approach. 

Individual RQs 

EPA is interested in receiving public 

comment on the selected methodology 

and on whether RQs for individual 

radionuclides are believed to be too low 

or too high. EPA would be interested in 

suggestions and data regarding what 

criteria the Agency should consider in 

technically or administratively adjusting 

a proposed RQ for an individual 

radionuclide. 

Concentration Cutoff 

Under this proposed rule, releases of 

large volumes of dilute material, which 

present little or no immediate danger to 

public health, could be reportable. 

Therefore, EPA is considering whether a 

concentration cutoff (expressed in curies 

per gram), below which the RQs for 

radionuclides would not apply (similar 

in principle to that used by DOT in 

defining radioactive material (see 

section III of this notice)) would be 

appropriate to eliminate unnecessary 

and excessive reporting. 

The basis of the DOT concentration 

cutoff is to avoid regulation of natural 

objects for which the application of 

transportation regulations governing 

radioactive materials is not intended. 

EPA is considering a similar 

concentration cutoff because there may 

be no benefit in requiring reports of 

releases of radioactive materials in such 

low concentrations. However, if a large 

quantity of low concentration material is 

released, the release may represent a 

threat to public health, welfare, and the 

environment to which the federal 

government may want to respond. 

EPA requests comments on the 

appropriateness of having a 

concentration cutoff and on what that 

cutoff should be. In particular, the 

Agency requests comment on using 0.002 

microcuries per gram (the DOT value) as 

a cutoff. 

V. Summary of Supporting Analyses 

Rulemaking protocol under Executive 

Order 12291 requires that proposed 

regulations be classified as major or 

non-major for purposes of review by the 

Office of Management and Budget 

(OMB). According to E.0.12291, major 

rules are regulations that are likely to 

result in: 

(1) An annual effect on the economy 

of $100 million or more; or 

(2) A major increase in costs or prices 

for consumers, individual industries, 

federal, state, or local government 

agencies, or geographic regions; or 

(3) Significant adverse effects on 

competition, employment, investment, 

productivity, innovation, or on the 

ability of United States-based 

enterprises to compete with foreignbased enterprises in domestic or export 

markets. 

The Economic Impact Analysis for the 

Proposed Reportable Quantities 

Adjustments for Radionuclides under 

section 102 of CERCLA (Economic 

Impact Analysis), available for 

inspection at Room LG—100, U.S. 

Environmental Protection Agency, 401 M 

Street, SW, Washington, DC 20460, 

shows that today's proposed regulation 

is non-major, because adoption of the 

proposed rule will result in an estimated 

total annual cost of $178,000 to the 

government and the regulated 

community, with the latter's share being 

less than $27,300 annually. 

The Regulatory Flexibility Act of 1980 , 

requires that a Regulatory Flexibility 

Analysis be performed for all rules that 

are likely to have a "significant impact 

on a substantial number of small 

entities." EPA certifies that this 

regulation will not have a significant 

impact on a substantial number of small 

entities. See Chapter Six of the 

Economic Impact Analysis. 

EPA requires ah Information Impact 

Analysis to be carried out for all rules 

that impose a paperwork burden on the 

public. This analysis estimates the 

burden imposed on parties outside EPA 

for activities such as recordkeeping or 

notification. It is anticipated that RQ 

adjustments will change the paperwork 

burden imposed on the regulated 

community for information collection 

associated with reporting releases. As 

estimated in Chapter Six of the 

Economic Impact Analysis, the 

paperwork burden of notification and 

recordkeeping on private parties will be 

approximately 43 additional 

notifications annually. 

In accordance with the Paperwork 

Reduction Act of 1980.44 U.S.C. 3501 et 

seq., the reporting or recordkeeping 

provisions that are included in this 

proposed rule have been submitted for 

approval to OMB under section 3504(h) 

of the Paperwork Reduction Act. Any 

final rule will include an explanation of 

how the reporting or recordkeeping 

provisions contained therein respond to 

any comments by OMB and the public. 

List of Subjects in 40 CFR Part 302 

Air pollution control, Chemicals, 

Hazardous materials, Hazardous 

materials transportation, Hazardous 

substances, Hazardous wastes, 

Intergovernmental relations, Natural 

resources, Source, byproduct and 

special nuclear materials, Mineral 

mining, Radioactive materials, 

Radionuclide, Reporting and 

recordkeeping requirements, Superfund. 

Waste treatment and disposal. Water 

pollution control. 

Dated: December 31.1988. 

Lee M. Thomas, 

Administrator. 

For the reasons set out.in the 

preamble, it is proposed to amend Title 

40 of the Code of Federal Regulations as 

follows: 

PART 302—DESIGNATION, 

REPORTABLE QUANTITIES, AND 

NOTIFICATION 

1. The authority citation for Part 302 is 

revised to read as follows: 

Authority: Sec. 102 of the Comprehensive 

Environmental Response, Compensation, and 

Liability Act of 1980, as amended, 42 U.S.C. 

9602; sees. 311 and 501(a) of the Federal 

Water Pollution Control Act, 33 U.S.C. 1321 

and 1361. 

§302.4 [Amended] 

2. In Section 302.4, Table 302.4 is 

amended by revising the entry for 

"Radionuclides" under the "Final RQ" 

column for "Pounds (kg)" to read: "§." 

3. In Section 302.4, Table 302.4 is 

amended by revising the footnote at the 

end of the table explaining "§" to read: 

"§—the adjusted RQs for 

radionuclides may be found in 

Appendix B to this table." 

4. In Section 302.4, Table 302.4 is 

amended by adding the following table 

as Appendix B: 

APPENDIX B—RADIONUCLIDES 

Radionuclide 

RADIONUCLIDES 

Actinium-224 

Actinium-225 

Actinium-226 

Actinhim-227 

Actinhim-228 

Aluminum-26 

Americium-237 

Americium-238 

Americium-239 

Americium-240 

Americium-241 

Americium-242m 

Americtum-242 

Ameficium-243 

Americium-244m 

Americium-244 

Americium-245 

Americium-246m 

Americium-246 

Antimony-115 „.... 

Antimony-116m 

Antimony-116 

Antimony-117 

Antimony-118m 

Antimony-119 

Antimony-120 (16 min)...: 

Atomic 

Number 

89 

89 

89 

89 

89 

13 

95 

95 

95 

95 

95 

95 

95 

95 

95 

95 

95 

95 

95 

51 

51 

51 

51 

51 

51 

51 

Proposed 

R Q (CO 

1& 

100 

1 

10 

0.001 

10 

10 

100 

10 

100 

10 

0.01 

0.01 

100 

0.01 

1000 

10 

1000 

10 

10 

10 

10 

10 

100 

10 

100 

1000 
P.13 

Federal Register / Vol. 52, No. 50 / Monday, March 16, 1987 / Proposed Rules

 T 8183 

APPENDIX B—RADIONUCLIDES— 

Continued 

Radionuclide 

Antimony-120 (5.76 

day). 

Antimony-122 , 

Antimony-124m 

"Antimony-124 

Antimony-125 

Antimony-126m 

Antimony-126 

Antimony-127 

Antimony-128 (10.4 

min). 

Antimony-128 (9.01 hr) 

Antimony-129 

Antimony-130 

Antimony-131 

Argon-39 

Argon-41 

Arsenic-69 

Arsenic-70 

Arsenic-71 

Arsenic-72 

Arsenic-73 

Arsenic-74 

Arsenic-76 

Arsenic-77 

Arsenic-78 

Astatine-207 

Astatine-211 

Barium-126 

Barium-128 

Barium-131m 

Barium-131 

Barium-133m 

Barium-133 

Barium-135m 

Barium-139 

Barium-140 

Barium-141 

Barium-142 

Berkelium-245 

Berkelium-246 

Berkelium-247 

Berkelium-249 

Berkelium-250 

Beryllium-7 

Beryllium-10 

Bismuth-200 

Bismuth-201 

Bismuth-202 

Bismuth-203 

Bismuth-205 

Bismuth-206 

Bismuth-207 

Bismuth-210m 

Bismuth-210 

Bismuth-212 

Bismuth-213 

Bismuth-214 

Bromine-74m 

Bromine-74 

Bromine-75 

Bromine-76 

Bromine-77 

Bromine-80m 

Bromine-80 

Bromine-82 

Bromine-83 

Bromine-84 

Atomic 

Number 

51 

51 

51 

51 

51 

51 

51 

51 

51 

51 

51 

51 

51 

18 

18 

33 

33 

33 

33 

33 

33 

33 

33 

33 

85 

85 

56 

56 

56 

56 

56 

56 

56 

56 

56 

56 

56 

97 

97 

97 

97 

97 

4 

4 

83 

83 

83 

83 

83 

83 

83 

83 

83 

83 

83 

83 

35 

35 

35 

35 

35 

35 

35 

35 

35 

35 

Proposed 

RQ (Ci) 

10 

10 

1000 

10 

10 

10 

10 

10 

10 

10 

10 

10 

10 

1000 

10 

1000 

10 

100 

10 

100 

10 

10 

100 

10 

10 

1 

100 

100 

100 

10 

100 

100 

100 

100 

100 

10 

10 

100 

10 

0.01 

1 

10 

100 

1 

10 

10 

100 

10 

10 

10 

10 

0.1 

10 

100 

100 

10 

10 

10 

10 

10 

100 

1000 

100 

10 

1000 

10 

APPENDIX B—RADIONUCLIDES— 

Continued 

Radionuclide 

Cadmium-104 

Cadmium-107 

Cadmium-109 

Cadmium-113m 

Cadmium-113 

Cadmium-115m 

Cadmium-115 

Cadmium-117m 

Cadmium-117 

Calcium-41 

Calcium-45 

Calcium-47 

Californium-244 

Calitornium-246 

Californium-248 

Californium-249 

Californium-250 

Calitornium-251 

Californium-252 

Californium-253 

Californium-254 

Carbon-11 

Carbon-14 

Cerium-134 

Cerium-135 

Cerium-137m 

Cerium-137 

Cerium-139 

Cerium-141 

Cerium-143 

Cerium-144 

Cesium-125 

Cesium-127 

Cesium-129 

Cesium-130 

Cesium-131 

Cesium-132 

Cesium-134m 

Cesium-134 

Cesium-135m 

Cesium-135 

Cesium-136 

Cesium-137 

Cesium-138 

Chlorine-36 

Chlorine-38 

Chlorine-39 

Chromium-48 

Chromium-49 

Chromium-51 

Cobalt-55 

Cobalt-56 

Cobalt-57 

Cobalt-58m 

Cobalt-58 

Cobalt-60m 

Cobalt-60 

Cobalt-61 

Cobalt-62m.: 

Copper-60 

Copper-61 

Copper-64 

Copper-67 

Curium-238 ; 

Curium-240 

Curium-241 

Curium-242 

Atomic 

Number 

48 

48 

48 

48 

48 

48 

48 

48 

48 

20 

20 

20 

98 

98 

98 

98 

98 

98 

98 

98 

98 

6 

6 

58 

58 

58 

58 

58 

58 

58 

58 

55 

55 

55 

55 

55 

55 

55 

55 

55 

55 

55 

. 55 

55 

17 

17 

17 

24 

24 

24 

27 

27 

27 

27 

27 

27 

27 

27 

27 

29 

29 

29 

29 

96 

96 

96 

96 

96 

Proposed 

RQ (Ci) 

100 

1000 

10 

1 

1 

10 

10 

10 

10 

1000 

100 

10 

1000 

10 

0.1 

0.01 

0.01 

0.01 

0.1 

10 

0.1 

10 

10 

100 

10 

1000 

1000 

100 

10 

100 

1 

100 

100 

100 

100 

1000 

10 

1000 

10 

10 

100 

10 

10 

10 

100 

10 

10 

10 

100 

1000 

10 

10 

100 

1000 

10 

1000 

10 

100 

10 

10 

100 

100 

100 

1000 

1 

10 

1 

0.01 

APPENDIX B—RADIONUCLIDES— 

Continued 

Radionuclide 

Curium-244 

Curium-245 

Curium-246 

Curium-247 

Curium-248 

Curium-249 

Dysprosium-155 

Dysprosium-157 

Dysprosium-159 

Dysprosium-165 

Dysprosium-166 

Einsteinium-250 

Einsteinium-251 

Einsteinium-253 

Einsteinium-254m 

Einsteinium-254 

Erbium-161 

Erbium-165 

Erbium-169 

Erbium-171 

Erbium-172 

Europium-145 

Europium-146 

Europium-147 

Europium-148 

Europium-149 

Europium-150 (12.6 hr). 

Europium-150 (34.2 yr). 

Europium-152m 

Europium-152 

Europium-154 

Europium-155 

Europium-156 

Europium-157 

Europium-158 

Fermium-252 

Fermium-253 

Fermium-254 

Fermium-255 

Fermium-257 

Fluorine-18 

Francium-222 

Francium-223 

Gadolinium-145 

Gadolinium-146 

Gadolinium-147 

Gadolinium-148 

Gadolinium-149 

Gadolinium-151 

Gadolinium-152 

Gadolinium-153 

Gadolinium-159 

Gallium-65 

Gallium-66 

Gallium-67 

Gallium-68 

Gallium-70 

Gallium-72 

Gallium-73 

Germanium-66 

Germanium-67 

Germanium-68 

Germanium-69 

Germanium-71 

Germanium-75 

Germanium-77 

Germanium-78 

Gold-193 

Atomic 

Number 

96 

96 

96 

96 

96 

96 

66 

66 

66 

66 

66 

99 

99 

99 

99 

99 

68 

68 

68 

68 

68 

63 

63 

63 

63 

63 

63 

63 

63 

63 

63 

63 

63 

63 

63 

100 

100 

100 

100 

100 

9 

87 

87 

64 

64 

64 

64 

64 

64 

64 

64 

64 

31 

31 

31 

31 

31 

31 

31 

32 

32 

32 

32 

32 

32 

32 

32 

79 

Proposed 

RQ (Ci) 

0.01 

0.01 

0.01 

0.01 

0.001 

1000 

10 

100 

100 

100 

10 

10 

100 

10 

1 

0.1 

10 

1000 

100 

100 

10 

10 

10 

10 

10 

1000 

1000 

10 

100 

10 

10 

10 

10 

10 

10 

10 

10 

100 

10 

1 

1000 

100 

100 

10 

10 

10 

0.001 

100 

100 

0.001 

10 

100 

10 

10 

100 

1000 

1000 

10 

100 

100 

100 

10 

10 

1000 

1000 

10 

100 

100 
P.14 

6184 Federal Register / Vol. 52, No, 50 / Monday, March 16, 1987 / Proposed Rules 

APPENDIX B—RADIONUCLIDES— 

Continued 

Radionuclide 

Gold-194 ..„ 

Gold-195 

Gold-198m _ 

Gold-198 _ 

Gold-199 

Gotd-200m 

Gold-200 

Gold-201 

Hainium-170 

Hafnium-172 

Hafnium-173 

Hafnium-175 

Hafnhim-177m 

Hafnium-178m 

Hafnium-179m 

Hafnium-180m 

Hafnium-181 

Hafnium-182m._ 

Hafnium-182 

Hafnhim-183 

Hafnium-184 

Holmium-157 

Holmium-161 

Holmium-162m 

Holmium-162 _ 

Holmhjm-164m..._ 

Holmium-166m 

Holmium-166 

Holmium-167 _ 

lndium-110 (69.1 min) 

lndium-110 (4.9 hr) 

lndium-111 

lndium-112 

lndium-113m ..„ 

lndium-114m 

lndium-115m 

lndium-115 

lndium-116m 

lndium-117m 

lndium-117 

lndium-119m _ 

Iodine-120 

lodine-121_ _ 

lodine-125 „ 

Iodine-126 „ 

Iodine-128 

lodine-129 

lodine-130 

lodine-131 

lodine-132m 

lodine-132 

lodine-133 

lodine-134 

lodine-135 

Iridium-182 

lridium-184 

lridium-185 

Iridium-186 _ 

Iridium-187 

Atomic 

Number 

79 

79 

79 

79 

79 

79 

79 

79 

72 

72 

72 

72 

72 

72 

72 

72 

72 

72 

72 

72 

72 

67 

67 

67 

67 

67 

67 

67 

67 

67 

67 

67 

1 

49 

49 

49 

49 

49 

49 

49 

49 

49 

49 

49 

49 

49 

53 

53 

53 

53 

53 

53 

53 

53 

53 

53 

53 

53 

53 

53 

53 

53 

77 

77 

77 

77 

77 

77 

Proposed 

RQ (Ci) 

10 

100 

10 

10 

100 

10 

100 

1000 

10 

1 

100 

100 

10 

0.1 

10 

10 

10 

10 

0.1 

10 

100 

100 

100 

100 

1000 

10 

100 

1000 

1000 

1 

1000 

100 

100 

100 

10 

10 

10 

100 

100 

10 

100 

0.1 

10 

10 

10 

1000 

10 

10 

100 

10 

0.1 

0.1 

0.1 

100 

0.01 

1 

0.1 

10 

10 

1 

10 

10 

10 

10 

10 

1 0

 _ 

100 I 10 

APPENDIX B-RADIONUCLIDES— 

Continued 

Radionuclide 

lridiim-189 

Iridium-190m „.. 

lridium-190 

Iridium-192m 

lridium-192 „.. 

Iridium-194m 

lridium-194 

Iridium-195m...-

lridium-195 „... 

lron-52 

lron-55 

lron-59 „.. 

lron-60 „ 

Krypton-74 

Krypton-76 

Krypton-77 

Krypton-79 

Krypton-81 _.. 

Krypton-83m 

Krypton-85m 

Krypton-85 

Krypton-87 

Krypton-88 

Lanthanum-131.._.. 

Lanthanum-132 

Lanthanum-135 

Lanthanum-137 

Lanthanum-138 

Lanthanum-140 

Lanthanum-141 

Lanthanum-142 

Lanthanum-143 

Lead-195m 

Lead-198 

Lead-199.. 

Lead-200 

Lead-201 

Lead-202m 

Lead-202 _ 

Lead-203 

Lead-205 

Lead-209 

Lead-210 

Lead-211 

Lead-212 

Lead-214 

Lutetium-169 

Lutetium-170 

Lutetium-171 

Lutetium-172 

Lutetium-173 

Lutetium-174m 

Lutetium-174 

Lutetium-176m 

Lutetium-176 

Lutetium-177m 

Lutetium-177 

Lutetium-178m 

Lutetium-178 

Lutetium-179 

Magnesium-28 

Manganese-51 

Manganese-52m... 

Manganese-52 

Manganese-53 

Manganese-54 

Manganese-56 

Mendetevium-257.. 

Atomic 

Number 

77 

77 

77 

77 

77 

77 

77 

77 

77 

26 

26 

26 

26 

36 

36 

36 

36 

36 

36 

36 

36 

36 

36 

57 

57 

57 

57 

57 

57 

57 

57 

57 

82 

82 

82 

82 

82 

82 

82 

82 

82 

82 

62 

82 

82 

82 

71 

71 

71 

71 

71 

71 

71 

71 

71 

71 

71 

71 

71 

71 

12 

25 

25 

25 

25 

25 

25 

101 

Proposed 

RQ (Ci) 

100 

1000 

10 

100 

10 

10 

10 

100 

100 

100 

1000 

10 

1 

10 

10 

10 

100 

1000 

1000 

100 

100 

10 

10 

100 

10 

1000 

10 

1 

10 

100 

10 

100 

10 

100 

10 

100 

10 

10 

10 

100 

100 

1000 

0.1 

100 

10 

100 

10 

10 

10 

10 

100 

100 

10 

100 

1 

10 

100 

100 

100 

100 

10 

1000 

10 

10 

1000 

10 

10 

100 

APPENDIX B—RADIONUCLIDES— 

Continued 

Radionuclide 

Mendelevium-258 

Mercury-193m 

Mercury-193 

Mercury-194 „„ 

Mercury-195m 

Mercury-195 

Mercury-197m 

Mercury-197 

Mercury-199m 

Mercury-203 

Molybdenum-90 

Molybdenum-93m 

Molybdenum-93 

Molybdenum-99 

Molybdenum-101 

Neodymium-136 

Neodymium-138 

Neodymium-139m 

Neodymium-139 

Neodymium-141 

Neodymium-147 

Neodymium-149 

Neodymium-151 

Neptunium-232 

Neptunium-233 „ 

Neptunium-234 

Nepturtium-235 

Neptunium-236 (1.2 E 

5yr). 

Neptunium-236 (22.5 

hr). 

Neptunium-237 _ 

Neptunium-238 

Neptunium-239 „ 

Neptunium-240 „ 

Nickel-56 -

Nickel-57 -

Nickel-59 

Nickel-63 

Nickel-65 

Nickel-66 

Niobium-88 

Ntobium-89 (66 min).., 

Niobium-89 (122 min). 

Niobium-90 

Niobium-93m 

Niobium-94 

Niobium-95m 

Niobium-95 „ 

Niobium-96 „ 

Niobtum-97 

Niobium-98 

Osmium-180 

Osmium-181 

Osmium-182 

Osmium-185 

Osmium-189m .„ 

Osmium-191 m._ 

Osmium-191 

Osmium-193 

Osmium-194 

Palladium-100..„ 

Palladium-101 

Palladium-103.._ 

Palladium-107..„ 

Palladium-109 

Phosphorus-32 

Phosphorus-33 

Atomic 

Number 

101 

80 

80 

80 

80 

80 

80 

80 

80 

80 

42 

42 

42 

42 

42 

60 

60 

60 

60 

60 

60 

60 

60 

93 

93 

93 

93 

93 

93 

93 

93 

93 

93 

28 

28 

28 

28 

28 

28 

41 

41 

41 

41 

41 

41 

41 

41 

41 

41 

41 

76 

76 

76 

76 

76 

76 

76 

76 

76 

46 

46 

46 

46 

46 

15 

15 

Proposed 

RQ (Ci) 

1 

10 

10 

1 

100 

100 

100 

100 

100 

10 

10 

10 

100 

100 

10 

100 

1000 

10 

100 

1000 

100 

10 

10 

10 

1000 

10 

1000 

0.1 

100 

0.01 

10 

100 

10 

10 

10 

1000 

1000 

10 

100 

10 

10 

10 

1 

100 

10 

100 

10 

10 

10 

100 

1000 

10 

10 

10 

1000 

100 

100 

100 

1 

100 

100 

1000 

100 

1000 

1 

10 
P.15 

Federal Register / Vol. 52, No. 50 / Monday, March 16, 1987 / Proposed Rules 8185 

APPENDIX B—RADIONUCLIDES— 

Continued 

Radionuclide 

Platinum-189 

Platinum-191 

Praseodymium-136 

Praseodymium-137 

Praseodymium-138m 

Praseodymium-139 

Praseodymium-142m 

Praseodymium-143 

Praseodymium-147 

Atomic 

Number 

78 

78 

78 

78 

78 

78 

78 

78 

78 

78 

78 

94 

94 

94 

94 

94 

94 

94 

94 

94 

94 

94 

94 

84 

84 

84 

84 

19 

19 

19 

19 

19 

59 

59 

59 

59 

59 

59 

59 

59 

59 

59 

61 

61 

61 

61 

61 

61 

61 

61 

61 

61 

61 

91 

91 

91 

91 

91 

91 

91 

88 

88 

88 

88 

88 

88 

86 

86 

Proposed 

RQ (Ci) 

10 

100 

100 

100 

100 

1000 

100 

100 

100 

100 

10 

1000 

1000 

0.1 

1000 

0.0.1 .... 

0 01 

0 01 

1 

0 01 

1000 

0 01 

100 

10 

10 

10 

0 1 

100 

100 

10 

10 

10 

10 

1000 

10 

100 

1000 

100 

100 

1000 

1000 

10 

10 

100 

10 

100 

10 

10 

10 

10 

1000 

10 

100 

100 

10 

10 

0 01 

10 

100 

10 

1 

10 

1 

1 

100 

1 

0.1 

0.1 

APPENDIX B—RADIONUCLIDESContinued 

Radionuclide 

Rhenium-177 

Rhenium-178 

Rhenium-181 

Rhenium-182 (12.7 hr)... 

Rhenium-182 (64.0 hr)... 

Rhenium-184m 

Rhenium-184 

Rhenium-186m 

Rhenium-186 

Rhenium-187 

Rhenium-188m 

Rhenium-188 

Rhenium-189 

Rhodium-99m 

Rhodium-99 

Rhodium-100 

Rhodium-101 m 

Rhodium-101 

Rhodium-102m 

Rhodium-102 

Rhodium-103m 

Rhodium-105 

Rhodium-106m 

Rhodium-107 

Rubidium-79 

Rubidium-81 m 

Rubidium-82m 

Rubidium-83 

Rubidium-84 

Rubidium-86 

Rubidium-87 

Rubidium-88 

Rubidium-89 

Ruthenium-94 

Ruthenium-97 

Ruthenium-103 

Ruthenium-105 

Ruthenium-106 

Samarium-141m 

Samarium-141 

Samarium-142 

Samarium-145 

Samarium-146 

Samarium-147 

Samarium-151 

Samarium-153 

Samarium-155 

Samarium-156 

Scandium-43 

Scandium-44m 

Scandium-44 

Scandium-46 

Scandium-47 

Scandium-48 

Scandium-49 

Selenium-70 

Selenium-73m 

Selenium-73 

Selenium-75 

Selenium-79 

Selenium-81 m 

Selenium-81 

Selenium-83 

Silicon-31 

Silicon-32 

Silver-102 

Silver-103 

Atomic 

Number 

75 

75 

75 

75 

75 

75 

75 

75 

75 

75 

75 

75 

75 

45 

45 

45 

45 

45 

45 

45 

45 

45 

45 

45 

37 

37 

37 

37 

37 

37 

37 

37 

37 

37 

44 

44 

44 

44 

44 

62 

62 

62 

62 

62 

62 

62 

62 

62 

62 

21 

21 

21 

21 

21 

21 

21 

34 

34 

34 

34 

34 . 

34 

34 

34 

14 

14 

47 

47 

Proposed 

RQ (Ci) 

10 

10 

10 

10 

10 

100 

10 

10 

100 

1000 

1000 

100 

100 

10 

10 

10 

100 

100 

10 

10 

1000 

100 

10 

100 

10 

100 

10 

10 

10 

10 

100 

1000 

10 

10 

10 

100 

10 

10 

1 

10 

10 

100 

100 

0.01 

0.01 

10 

1000 

100 

100 

100 

10 

10 

10 

100 

10 

1000 

100 

100 

10 

100 

100 

1000 

1000 

10 

100 

1 

10 

10 

APPENDIX B—RADIONUCLIDES— 

Continued 

Radionuclide 

Silver-104m 

Sitver-104 

Silver-105 

Silver-106m 

Silver-106 

Siiver-108m 

Silver-110m 

Silver-111 

Silver-112 

Silver-115 

Sodium-22 

Sodium-24 

Strontium-80 

Strontium-81 

Strontium-83 

Strontium-85m 

Strontium-85 

Strontium-87m 

Strontium-89 

Strontium-90 

Strontium-91 

Strontium-92 

Sulfur-35 

Tantalum-172 

Tantalum-173 

Tantalum-174 

Tantalum-175 

Tantalum-176 

Tantalum-177 

Tantalum-178 

Tantalum-179 

Tantalum-180m... 

Tantalum-180 

Tantalum-182m... 

Tantalum-182 

Tantalum-183 

Tantalum-184 

Tantalum-185 

Tantalum-186 

Technetium-93m. 

Technetium-93 

Technetium-94m. 

Technetium-94 

Technetium-96m. 

Technetium-96 

Technetium-97m. 

Technetium-97 

Technetium-98 

Technetium-99m. 

Technetium-99 

Technetium-101 .. 

Technetium-104.. 

Tellurium-116 

Tellurium-121m.... 

Tellurium-121 

Tellurium-123m.... 

Tellurium-123 

Tellurium- '25m.... 

Tellurium-127m.... 

Tellurium-127 

Tellurium-i29m.... 

Tellurium-129 

Tellurium-131m.... 

Tellurium-131 

Tellurium-132 

Tellurium-133m.... 

Tellurium-133 

Tellurium-134 

Atomic 

Number 

47 

47 

47 

47 

47 

47 

47 

47 

47 

47 

11 

11 

38 

38 

38 

38 

38 

38 

38 

38 

38 

38 

16 

73 

73 

73 

73 

73 

73 

73 

73 

73 

73 

73 

73 

73 

73 

73 

73 

43 

43 

43 

43 

43 

43 

43 

43 

43 

43 

43 

43 

43 

52 

52 

52 

52 

52 

52 

52 

52 

52 

52 

52 

52 

52 

52 

52 

52 

Proposed 

RQ (Ci) 

10 

100 

10 

10 

10 

10 

10 

100 

10 

100 

100 

1 

10 

10 

100 

100 

10 

100 

10 

1 

10 

10 

10 

10 

100 

10 

10 

10 

100 

100 

1000 

1000 

10 

100 

10 

10 

10 

100 

10 

10 

10 

10 

10 

1000 

10 

100 

1000 

10 

100 

100 

100 

10 

100 

100 

10 

100 

100 

100 

100 

1000 

100 

100 

10 

100 

100 

ioo 

10 

10 
8186 Federal Register / Vol. 52, No. 50 / Monday, March 16, 1987 / Proposed Rules 

APPENDIX B—RADIONUCLIDES— 

Continued 

Radionuclide 

Tertatum-147 

Terbium-149 

Terbium-150 

Terbium-151 

Terbium-153 

Terbium-154 

Terbium-155 

Terbium-156m (5.0 hr).... 

Terbium-156m (24.4 hr).. 

Terbium-156 

Terbium-157 

Terbium-158 

Terbium-160 

Terbium-161 

Thallium-194m 

Thallium-194 

Thallium-195 

Thallium-197 

Thallium-198m 

Thallium-198 

Thallium-199 

Thallium-200 

Thallium-201 

Thallium-202 

Thallium-204 

Thorium-226 

Thorium-227 

Thorium-228 

Thorium-229 

Thorium-230 

Thorium-231 

Thorium-232 

Thorium-234 

Thulium-162 

Thulium-166 

Thulium-167 

Thulium-170 

Thulium-171 

Thulium-172 

Thulium-173 

Thulium-175 

Tin-110 

Tin-111 

Atomic 

Number 

65 

65 

65 

65 

65 

65 

65 

65 

65 . 

65 

65 

65 

65 

65 

81 

81 

81 

81 

81 

81 

81 

81 

81 

81 

81 

90 

90 

90 

90 

90 

90 

90 

90 

69 

69 

69 

69 

69 

69 

69 

69 

50 

50 

Proposed 

RQ (Ci) 

10 

10 

10 

10 

100 

10 

100 

1000 

1000 

10 

100 

10 

10 

1000 

10 

10 

10 

100 

10 

10 

100 

10 

1000 

10 

100 

100 

1 

0.01 

0.001 

0.01 

100 

0.001 

1000 

10 

10 

100 

10 

100 

10 

10 

10 

100 

100 

APPENDIX B—RADIONUCLIDES— 

Continued 

Radionuclide 

Tin-113 

Tin-117m 

Tin-119m 

Tin-121 m 

Tin-121 

Tin-123m „... 

Tin-123 

Tin-125 

Tin-126 

Tin-127 

Tin-128 

Titanium-44 

Titanium-45 

Tungsten-176 

Tungsten-177 

Tungsten-178 

Tungsten-179 

Tungsten-181 

Tungsten-185 

Tungsten-187 

Tungsten-188 

Uranium-230 

Uranium-231 

Uranium-232 

Uranium-233 

Uranium-234 

Uranium-235 

Uranium-236 

Uranium-237 

Uranium-238 

Uranium-239 

Uranium-240 

Vanadium-47 

Vanadium-48 

Vanadium-49 

Xenon-120 

Xenon-121 

Xenon-122 

Xenon-123 

Xenon-125 

Xenon-127 

Xenon-129m 

Xenon-131m 

Atomic 

Number 

50 

50 

50 

50 

50 

50 

50 

50 

50 

50 

50 

22 

22 

74 

74 

74 

74 

74 

74 

74 

74 

92 

92 

92 

92 

92 

92 

92 

92 

92 

92 

92 

23 

23 

23 

54 

54 

54 

54 

54 

54 

54 

54 

Proposed 

RQ (Ci) 

100 

100 

100 

100 

1000 

100 

100 

100 

10 

10 

10 

1 

100 

100 

10 

100 

1000 

1000 

100 

10 

10 

0.1& 

100& 

0.01 a 

0.1& 

0.1a 

0.1a 

0.1a 

10& 

0.1 a 

1000a 

10a 

1000 

10 

1000 

10 

10 

100 

10 

100 

10 

1000 

1000 

APPENDIX B—RADIONUCLIDES— 

Continued 

Radionuclide 

Xenon-133m... 

Xenon-133 

Xenon-135m... 

Xenon-135 

Xenon-138 

Ytterbium-162. 

Ytterbium-166. 

Ytterbium-167. 

Ytterbium-169. 

Ytterbium-175. 

Ytterbium-177. 

Ytterbium-178. 

Yttrium-86m.... 

Yttrium-86 

Yttrium-87 

Yttrium-88 

Yttrium-90m.... 

Yttrium-90 

Yttrium-91m.... 

Yttrium-91 

Yttrium-92 

Ytrrium-93 

Yttrium-94 

Yttrium-95 

Zinc-62 

Zinc-63 

Zinc-65..._ 

Zinc-69m 

Zinc-69 

Zinc-71m 

Zinc-72 

Zirconium-86... 

Zirconium-88... 

Zirconium-89... 

Zirconium-93... 

Zirconium-95... 

Zirconium-97... 

Atomic 

Number 

54 

54 

54 

54 

54 

70 

70 

70 

70 

70 

70 

70 

39 

39 

39 

39 

39 

39 

39 

39 

39 

39 

39 

39 

30 

30 

30 

30 

30 

30 

30 

40 

40 

40 

40 

40 

40 

Proposed 

RQ (Ci) 

100 

100 

10 

10 

10 

100 

10 

100 

100 

100 

100 

100 

100 

10 

10 

10 

10 

100 

10 

10 

100 

100 

10 

10 

10 

100 

10 

10 

1000 

10 

10 

100 

10 

100 

1 

10 

10 

a The adjusted RQ of one curie applies to 

all radionuclides not otherwise listed, except 

uranyl nitrate and uranyl acetate whose final 

adjusted RQs are 100 pounds. 

[FR Doc. 87-343 Filed 3-13-87; 8:45 am)