[Federal Register Volume 75, Number 64 (Monday, April 5, 2010)]
[Notices]
[Pages 17169-17170]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-7601]


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NUCLEAR REGULATORY COMMISSION

[Docket No. 50-331; NRC-2010-0107]


Nextera Energy Duane Arnold, LLC, Duane Arnold Energy Center; 
Exemption

1.0 Background

    NextEra Energy Duane Arnold, LLC, formerly FPL Energy Duane Arnold, 
LLC (the licensee) is the holder of Facility Operating License No. DPR-
49, which authorizes operation of the Duane Arnold Energy Center (Duane 
Arnold). The facility consists of a boiling-water reactor located in 
Linn County in the State of Iowa. The licensee was authorized to change 
its name by Amendment No. 275, dated November 13, 2009, to the Facility 
Operating License. The license provides, among other things, that the 
facility is subject to all rules, regulations, and orders of the 
Nuclear Regulatory Commission (NRC, the Commission) now or hereafter in 
effect. In a letter dated March 4, 2009, FPL Energy Duane Arnold, LLC 
requested exemption from certain requirements of 10 CFR part 50, 
Appendix J.

2.0 Request/Action

    Title 10 of the Code of Federal Regulations (10 CFR), Appendix J 
specifies the leakage test requirements, schedules, and acceptance 
criteria for tests of the leak-tight integrity of the primary reactor 
containment and systems and components which penetrate the containment. 
Option B of Appendix J is entitled ``Performance-Based Requirements.'' 
Option B, Section III.A., ``Type A Test,'' requires, among other 
things, that the overall integrated leakage rate must not exceed the 
allowable leakage rate (La) with margin, as specified in the Technical 
Specifications (TSs).
    The overall integrated leak rate, is defined in 10 CFR part 50, 
Appendix J as ``the total leakage rate through all tested leakage 
paths, including containment welds, valves, fittings, and components 
that penetrate the containment system.'' This includes the contribution 
from main steam isolation valve (MSIV) leakage. The licensee has 
requested exemption from Option B, Section III.A requirements to permit 
exclusion of MSIV leakage from the overall integrated leak rate test 
measurement. Main steam leakage includes leakage through all four main 
steam lines and the main steam drain line.
    Option B, Section III.B of 10 CFR part 50, Appendix J, ``Type B and 
C Tests,'' requires, among other things, that the sum of the leakage 
rates at accident pressure of Type B tests and pathway leakage rates 
from Type C tests be less than the performance criterion (La) with 
margin, as specified in the TSs. The licensee also requests exemption 
from this requirement, to permit exclusion of the main steam pathway 
leakage contributions from the sum of the leakage rates from Type B and 
Type C tests.
    The licensee requests this exemption because the main steam pathway 
leakage is treated separately from the remainder of the assumed leakage 
from primary containment in the design basis loss-of-coolant accident 
(DBA LOCA) analysis. The MSIV leakage effluent has a different pathway 
to the environment, when compared to a typical containment penetration. 
The licensee has analyzed the MSIV and main steam pathway leakage 
separately from the overall containment integrated leakage, local 
leakage across pressure retaining, leakage limiting boundaries, and 
containment isolation valve leakage in its dose consequence analysis. 
By currently including the main steam pathway leakage in with the rest 
of the primary containment leakage actual test results, it is 
essentially being accounted for twice in the dose analysis.
    In summary, by application dated March 4, 2009, the licensee 
requested an exemption for the Duane Arnold Energy Center (Duane 
Arnold). The proposed change will exempt Duane Arnold from certain 
requirements of Appendix J to 10 CFR part 50. Specifically, the 
licensee is requesting a permanent exemption to permit exclusion of the 
main steam pathway leakage contributions from the overall integrated 
leakage rate (Type A) test measurement and from the sum of the leakage 
rates from local leakage rate (Type B and Type C) tests.

3.0 Discussion

    Pursuant to 10 CFR 50.12, the Commission may, upon application by 
any interested person or upon its own initiative, grant exemptions from 
the requirements of 10 CFR part 50 when (1) the exemptions are 
authorized by law, will not present an undue risk to public health or 
safety, and are consistent with the common defense and security; and 
(2) when special circumstances are present. Special circumstances are 
present whenever, according to 10 CFR 50.12(a)(2)(ii), ``Application of 
the regulation in the particular circumstances would not serve the 
underlying purpose of the rule or is not necessary to achieve the 
underlying purpose of the rule * * *.''

Authorized by Law

    The exemption would permit exclusion of the main steam pathway 
leakage contributions from the overall integrated leakage rate (Type A) 
test

[[Page 17170]]

measurement and from the sum of the leakage rates from local leakage 
rate (Type B and Type C) tests.
    As stated above, 10 CFR 50.12 allows the NRC to grant exemptions 
from the requirements of 10 CFR part 50, Appendix J. The NRC staff has 
determined that granting of the licensee's proposed exemption will not 
result in a violation of the Atomic Energy Act of 1954, as amended, or 
the Commission's regulations. Therefore, the exemption is authorized by 
law.

No Undue Risk to Public Health and Safety

    The underlying purposes of 10 CFR part 50, Appendix J is to assure 
that containment leak-tight integrity is maintained (a) as tight as 
reasonably achievable, and (b) sufficiently tight so as to limit 
effluent release to values bounded by the analyses of radiological 
consequences of design-basis accidents.
    In License Amendments 237 (regarding secondary containment 
OPERABILITY during movement of irradiated fuel and core alterations, 
dated April 16, 2001) and Amendment 240 (regarding Alternative Source 
Term (AST), dated July 31, 2001), the NRC approved the use of the AST 
(10 CFR 50.67) in the calculations of the radiological dose 
consequences of design basis accidents (DBAs) for the Duane Arnold 
Energy Center. The reactor design basis accident of concern is the 
design basis loss-of-coolant accident (LOCA). The NRC Staff Safety 
Evaluation accompanying Amendment 240 accepted that the main steam 
pathway leakage is treated separately from the remainder of the assumed 
leakage from primary containment in the LOCA analysis and once 
dispersed in the primary containment, the release to the environment is 
assumed to occur through three pathways: (1) The leakage of primary 
containment atmosphere (i.e., design leakage); (2) the leakage of 
primary containment atmosphere via design leakage through main steam 
isolation valves (MSIVs); and (3) the leakage from emergency core 
cooling systems (ECCS) that recirculate suppression pool water outside 
of the primary containment (i.e., design leakage). Since Amendment 237 
was specifically for the Fuel Handling Accident (FHA), which occurs 
during refueling when primary containment is not required, the main 
steam pathway leakage is not part of the release pathway for this 
reactor accident. Thus, no new accident precursors are created by 
exempting Duane Arnold from certain requirements of Appendix J to 10 
CFR part 50.
    Further, based on the above the determination that no new accident 
precursors are created by the proposed exemption, the probability of 
postulated accidents is not increased. Additionally, based on the above 
based on the way the main steam pathway leakage has previously been 
evaluated and accepted in the Duane Arnold radiological dose analysis 
for DBAs separately from the overall leakage associated with the 
primary containment boundary (Type A) and local leakage rate total 
(Type B and C), the consequences of postulated accidents are not 
increased. Therefore, there is no undue risk, since risk is probability 
multiplied by consequences, to public health and safety.

Consistent With Common Defense and Security

    The exemption would permit exclusion of the main steam pathway 
leakage contributions from the overall integrated leakage rate (Type A) 
test measurement and from the sum of the leakage rates from local 
leakage rate (Type B and Type C) tests. This change to accounting for 
leakage rate measurement has no relation to security issues. Therefore, 
the common defense and security is not impacted by this exemption.

Special Circumstances

    Special circumstances, in accordance with 10 CFR 50.12(a)(2), are 
present whenever application of the regulation in the particular 
circumstances would not serve the underlying purpose of the rule or is 
not necessary to achieve the underlying purpose of the rule. The 
underlying purpose of 10 CFR part 50, Appendix J, Option B, Paragraphs 
III.A and III.B is to ensure the actual radiological consequences of 
reactor accidents remain below those previously evaluated and accepted, 
as demonstrated by the actual, periodic measurement of containment 
leakage (Type A) and local leakage rate measurement (Type B and C).
    Although Type A, and Type B and C, leakage tests are defined as a 
measurement of those leakages, inclusion of the main steam pathway 
leakage results in double counting at the Duane Arnold Energy Center, 
once as a part of the actual containment leakage and again as part of 
main steam pathway leakage used in dose calculations. This is because 
Duane Arnold's revised design-basis radiological consequence analysis, 
reviewed and approved in Amendments 237 and 240 to Duane Arnold's 
operating license, address MSIV leakage as individual factors, 
exclusive of primary containment leakage. Therefore, requiring 
inclusion of main steam pathway leakage in the Type A, and Type B and 
C, leakage is not necessary to achieve the underlying purpose of the 
rule.
    Because compliance with 10 CFR part 50, Appendix J, Option B, 
Paragraphs III.A and III.B is not necessary to achieve the underlying 
purposes of the requirements, the special circumstances required by 10 
CFR 50.12(a)(2), for the granting of an exemption from 10 CFR Part 50, 
Appendix J, Option B, Paragraphs III.A and III.B exist.

4.0 Conclusion

    Accordingly, the Commission has determined that, pursuant to 10 CFR 
50.12, the exemption is authorized by law, will not present an undue 
risk to the public health and safety, and is consistent with the common 
defense and security. Also, special circumstances are present. 
Therefore, the Commission hereby grants to NextEra Energy Duane Arnold, 
LLC a permanent exemption from the requirements of 10 CFR part 50, 
Appendix J, Option B, Paragraphs III.A and III.B for the Duane Arnold 
Energy Center.
    Pursuant to 10 CFR 51.32, the Commission has determined that the 
granting of this exemption will not have a significant effect on the 
quality of the human environment [75 FR 13318; dated March 19, 2010].
    This exemption is effective upon issuance.

    Dated at Rockville, Maryland, this 29th day of March 2010.

    For the Nuclear Regulatory Commission.
Robert A. Nelson,
Acting Director, Division of Operating Reactor Licensing, Office of 
Nuclear Reactor Regulation.
[FR Doc. 2010-7601 Filed 4-2-10; 8:45 am]
BILLING CODE 7590-01-P