[Federal Register Volume 84, Number 185 (Tuesday, September 24, 2019)]
[Notices]
[Pages 50087-50089]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-20597]


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NUCLEAR REGULATORY COMMISSION

[Docket No. 030-29462; NRC-2019-0167]


Consideration of License Amendment Request for Exemption to NRC's 
Regulations to Remove Radioisotope Thermoelectric Generators From the 
Department of the Navy Master Material License No. 45-23645-01NA; 
Permit No. 45-4650-N1NP; Naval Nuclear Power Unit

AGENCY: Nuclear Regulatory Commission.

ACTION: Environmental assessment and finding of no significant impact; 
issuance.

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SUMMARY: The U.S. Nuclear Regulatory Commission (NRC) is granting an 
exemption under its regulations to the U.S. Navy from the 
decommissioning requirements as it relates to six Radioisotope 
Thermoelectric Generators (RTGs). The approval would allow the in-situ 
abandonment of six RTGs on the ocean bottom and subsequent termination 
of Naval Radioactive Materials Permit No. 45-4650-N1NP, Naval Nuclear 
Power Unit, Port Hueneme, California.

DATES: The environmental assessment and finding of no significant 
impact referenced in this document are available on September 24, 2019.

[[Page 50088]]


ADDRESSES: Please refer to Docket ID NRC-2019-0167 when contacting the 
NRC about the availability of information regarding this document. You 
may obtain publicly-available information related to this document 
using any of the following methods:
     Federal Rulemaking website: Go to https://www.regulations.gov and search for Docket ID NRC-2019-0167. Address 
questions about NRC docket IDs in Regulations.gov to Jennifer Borges; 
telephone: 301-287-9127; email: [email protected]. For technical 
questions, contact the individual listed in the FOR FURTHER INFORMATION 
CONTACT section of this document.
     NRC's Agencywide Documents Access and Management System 
(ADAMS): You may obtain publicly-available documents online in the 
ADAMS Public Documents collection at https://www.nrc.gov/reading-rm/adams.html. To begin the search, select ``Begin Web-based ADAMS 
Search.'' For problems with ADAMS, please contact the NRC's Public 
Document Room (PDR) reference staff at 1-800-397-4209, 301-415-4737, or 
by email to [email protected]. For the convenience of the reader, 
instructions about obtaining materials referenced in this document are 
provided in the AVAILABILITY OF DOCUMENTS section.
     NRC's PDR: You may examine and purchase copies of public 
documents at the NRC's PDR, Room O1-F21, One White Flint North, 11555 
Rockville Pike, Rockville, Maryland 20852.

FOR FURTHER INFORMATION CONTACT: Robin Elliott, U.S. Nuclear Regulatory 
Commission, Region I, 2100 Renaissance Boulevard, King of Prussia, 
Pennsylvania 19406; telephone: 610-337-5076; email: 
[email protected].

SUPPLEMENTARY INFORMATION: 

I. Introduction

    The NRC is considering issuance of an exemption to NRC 
decommissioning requirements for the Master Materials License held by 
the Department of the Navy, License 45-23645-01NA. The exemption would 
authorize the removal of six RTGs that are currently permitted for 
storage on the ocean bottom pending development of a viable disposal 
option. Therefore, as required by part 51 of title 10 of the Code of 
Federal Regulations (10 CFR), the NRC performed an environmental 
assessment. Based on the results of the environmental assessment that 
follows, the NRC has determined not to prepare an environmental impact 
statement for the amendment, and is issuing a finding of no significant 
impact.

II. Environmental Assessment

Description of the Proposed Action

    The proposed action would approve the licensee's August 29, 2018, 
license amendment and associated exemption request, resulting in the 
in-situ abandonment of six RTGs on the ocean bottom, therefore allowing 
termination of the permit supporting their storage.
    In 1970 and 1977, the Navy emplaced six RTGs in the deep oceans of 
the North Atlantic and South Pacific at depths greater than 10,000 feet 
to provide power for acoustic transponders. Currently, the RTGs are 
buried in silt and are irretrievable and further retrieval attempts are 
dangerous to personnel and equipment due to the depths involved, 
according to the U.S. Navy.
    Each RTG consists of a strontium-90 titanate heat source, 
thermoelectric generator, thermal insulation, biological shielding, and 
a pressure vessel/housing that is designed to withstand at least 20,000 
feet of ocean depth. The strontium pellets are sealed in a stainless 
steel liner. Final encapsulation of the liner is within an alloy that 
is resistant to seawater corrosion. The strontium capsules are designed 
to retain their integrity for at least 300 years while exposed to 
seawater at 10,000 pounds per square inch. Three of the six RTGs 
utilize a minimum of 270 pounds of depleted uranium shielding, while 
the remaining three utilized lead shielding. The half-life of 
strontium-90 is 28.8 years.
    In 1978, the Navy attempted to recover three of these RTGs using a 
manned submersible vehicle. This attempt failed and the deep 
submergence vehicle was damaged as part of that retrieval attempt. The 
Navy has expressed concern regarding danger to personnel and equipment 
in subsequent attempts to retrieve these RTGs, especially given their 
buried condition.
    Master Material License (MML) No. 45-23645-01NA was issued on March 
23, 1987, pursuant to 10 CFR part 30, and has been amended periodically 
since that time. This MML license authorizes, via Naval Radioactive 
Materials Permit No. 45-4650-N1NP, these six RTGs. They are currently 
licensed for storage on the ocean bottom pending development of a 
viable disposal option.
    License termination for such sources is usually accomplished under 
the regulatory framework of 10 CFR 30.36. The NRC is evaluating a 
request to exempt the Navy from these requirements in recognition of 
the irretrievability of these RTGs and to allow the Navy to remove 
these RTGs from their MML due to the fact that they no longer possess 
the material (i.e., these RTGs as irretrievable).

Need for the Proposed Action

    The Navy is requesting approval of this permitting action because 
it has ceased use of the RTGs, is unable to retrieve the sources, and 
further retrieval attempts are dangerous for personnel and equipment, 
and therefore to terminate the associated permits.

Environmental Impacts of the Proposed Action

    All of the RTGs are located on the ocean floor at depths greater 
than 10,000 feet deep and are designed to retain their strontium-90 
fuel for 300 years without deformation in a deep ocean environment. The 
half-life of strontium-90 is 28.8 years. Thus, at the design life of 
the RTG fuel capsules, 10 half-lives have passed, and the remaining 
activity of strontium will be indistinguishable from background levels.
    Based on photos the staff reviewed in the submittals, it appears 
that these RTGs are buried or semi-buried in silt. Additionally, each 
RTG has significant depleted uranium or lead shielding. This weight, 
coupled with the fact that these RTGs are buried in varying degrees in 
the ocean floor, have essentially immobilized them.
    The RTGs are in a state where they are semi or completely buried in 
silt. Given this, and the fact that during a previously attempt to 
retrieve these RTGs, the deep submergence vehicle was damaged, 
attempting the same activity again may damage vehicles attempting 
retrieval. As discussed by the Navy, there is a significant degree of 
(non-radiological) risk to personnel attempting another retrieval 
attempt due to the depth and silt accumulation of the RTGs.
    The NRC staff evaluated dose assessments if the strontium fuel 
capsules leak, and determined that doses would be minimal. These RTGS 
are located in remote areas of the ocean in the deep subsurface. There 
are a limited number of vehicles capable of reaching depths of 10,000 
feet or greater. Given this, the NRC staff finds it unlikely that these 
RTGs will be intruded upon, as discussed in greater detail in the NRC 
staff's safety evaluation report.

Environmental Impacts of the Alternatives to the Proposed Action

    Due to the largely administrative nature of the proposed action, 
its environmental impacts are small. Therefore, the only alternative 
the staff

[[Page 50089]]

considered is the no-action alternative, under which the staff would 
leave things as they are by simply denying the exemption request. This 
no-action alternative is not feasible as it conflicts with 10 CFR 
30.36(d), requiring that a license (permit in this case) be terminated 
when no principal activities under the license have been conducted for 
a period of 24 months. It has been greater than 24 months since the 
licensee (permittee) conducted any principal activities with the 
sources. Additionally, denying the amendment request would result in no 
change in current environmental impacts, since the sources are 
irretrievable. The environmental impacts of the proposed action and the 
no-action alternative are therefore the same, and would not result in 
significant environmental impacts. The staff also considered requiring 
the Navy to again attempt to retrieve RTGs as a potential alternative. 
However, based on the information submitted by the Navy and reviewed by 
the NRC staff, this is not a feasible option, and is therefore not 
considered further.

Agencies and Persons Consulted

    The NRC staff has determined that the proposed action is of a 
procedural nature, and will not affect listed species or critical 
habitat. Therefore, no further consultation is required under Section 7 
of the Endangered Species Act. The NRC staff has also determined that 
the proposed action is not the type of activity that has the potential 
to cause effects on historic properties. Therefore, no further 
consultation is required under Section 106 of the National Historic 
Preservation Act.

III. Finding of No Significant Impact

    The NRC staff has prepared this environmental assessment in support 
of the proposed action. On the basis of this environmental assessment, 
the NRC finds that there are no significant environmental impacts from 
the proposed action, and that preparation of an environmental impact 
statement is not warranted. Accordingly, the NRC has determined that a 
finding of no significant impact is appropriate.

IV. Availability of Documents

    The documents identified in the following table are available to 
interested persons through one or more of the following methods, as 
indicated.

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             Document                       Adams Accession No.
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Department of the Navy letter      ML19165A234
 dated August 29, 2018, ``Request
 for Technical Assistance In the
 Abandonment of Radioisotope
 Thermoelectric Generators In Siu
 At The Bottom Of The Ocean''.
``Consolidated Decommissioning     ML063000243
 Guidance: Decommissioning
 Process for Materials
 Licensees'' (NUREG-1757, Vol.1
 Rev. 2).
Safety Evaluation Report Approval  ML19226A177
 of Request to Remove RTGS from
 Department of Navy License,
 dated August 13, 2019.
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    Dated at Rockville, Maryland, this 18th day of September, 2019.

    For the Nuclear Regulatory Commission.
Joseph L. Nick,
Deputy Director, Division of Nuclear Materials Safety, Region I.
[FR Doc. 2019-20597 Filed 9-23-19; 8:45 am]
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