Nuclear Management Company, LLC; Monticello Nuclear Generating Plant; Exemption, 74958-74959 [E6-21152]

Agencies

• NUCLEAR REGULATORY COMMISSION

[Federal Register Volume 71, Number 239 (Wednesday, December 13, 2006)]
[Notices]
[Pages 74958-74959]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E6-21152]


=======================================================================
-----------------------------------------------------------------------

NUCLEAR REGULATORY COMMISSION

[Docket No. 50-263]


Nuclear Management Company, LLC; Monticello Nuclear Generating 
Plant; Exemption

1.0 Background

    Nuclear Management Company, LLC (the licensee), is the holder of 
Facility Operating License No. DPR-22 which authorizes operation of 
Monticello Nuclear Generating Plant (MNGP). The license provides, among 
other things, that the facility is subject to all rules, regulations, 
and orders of the U.S. Nuclear Regulatory Commission (NRC, the 
Commission) now or hereafter in effect.
    The facility consists of a boiling-water reactor located in Wright 
County in Minnesota.

2.0 Request/Action

    Appendix J to Title 10 of the Code of Federal Regulations (10 CFR) 
specifies the leakage rate test requirements, schedules, and acceptance 
criteria for tests of the leak-tight integrity of the primary reactor 
containment and systems and components that penetrate the containment. 
Option B, Paragraph III.A, of Appendix J requires that the overall 
integrated leakage rate must not exceed the allowable leakage (La) with 
margin, as specified in the plant's Technical Specifications. The 
overall integrated leakage rate, as specified in Appendix J, includes 
the contribution from main steam pathway leakage (i.e., through the 
four main steam lines and the main steam drain line at MNGP). Option B, 
Paragraph III.B requires that the sum of the leakage rates of Type B 
and Type C local leakage rate tests be less than the performance 
criterion (La) with margin, as specified in the Technical 
Specifications.
    By letter dated September 15, 2005, the licensee requested 
exemption from Option B, Section III.A, requirements to exclude main 
steam isolation valve (MSIV) leakage from the overall integrated leak 
rate test measurement, and exemption from Section III.B requirements to 
exclude the MSIV leakage from the sum of the Type B and Type C tests. 
The licensee stated that the MNGP MSIV leakage effluent has a different 
pathway to the environment when compared to a typical containment 
penetration, i.e., it is not directed into the secondary containment 
and filtered through the standby gas treatment system. Instead, the 
main steam leakage is collected and treated via an alternative leakage 
treatment pathway, having different mitigation characteristics.
    In performing accident analyses, it is appropriate to group various 
leakage effluents according to the treatment they receive before being 
released to the environment (e.g., from main steam pathways). 
Accordingly, the licensee's proposed exemption from the Appendix J 
requirements would more appropriately reflect the MNGP design which 
employs an alternative leakage treatment pathway. The calculated 
radiological consequences of the combined leakages were found to be 
within the criteria of 10 CFR 50.67 and GDC-19. The NRC staff reviewed 
the licensee's analyses and found them acceptable as described in a 
safety analysis accompanying an amendment regarding alternative source 
term methodology to be issued concurrently with this exemption. By 
separating the MSIV leakage acceptance criteria from the overall 
integrated leak rate test criteria, and from the Type B and C leakage 
sum limitation, the MNGP containment leakage testing program will be 
made more consistent with the limiting assumptions used in the 
associated accident consequences analyses. The amendment associated 
with this exemption will revise Technical Specification Surveillance 
Requirement 3.6.1.3.13 to limit the maximum allowable combined MSIV 
leakage to 200 standard cubic feet per hour, which is the analytical 
limit.
    Based on the foregoing, the separation of the main steam pathways 
from the other containment leakage pathways is warranted because a 
separate radiological consequence term has been provided for these 
pathways. The revised design basis radiological consequence analyses 
address these pathways as individual factors, exclusive of the primary 
containment leakage.

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. The licensee's exemption 
request was submitted in conjunction with an amendment application to 
employ the alternative source term (AST) methodology for design-basis 
accidents. The NRC staff had completed its review and is issuing the 
proposed amendment on the same date as this exemption. The exemption 
and amendment together would implement the AST methodology. The special 
circumstances associated with MSIV leakage testing are fully described 
in the licensee's September 15, 2005, application for amendment and 
exemption.

Authorized by Law

    This exemption would exempt Nuclear Management Company from 
requirements in 10 CFR Part 50, Appendix J, thus (1) Excluding MSIV 
leakage in the overall integrated leakage rate test measurement 
required by Section III. A of Appendix J, Option B; and (2) excluding 
the sum of local leak rate test measurements required by Section III.B 
of Appendix J, Option B. As stated above, 10 CFR 50.12 allows the NRC 
to grant exemptions from the requirements of 10 CFR Part 50. 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 proposed exemption affects only the radiological dose analysis 
models and the way containment leak-tightness is measured. No new 
accident precursors are created by the exemption; accordingly, the 
probability of postulated accidents is not increased and the 
consequences of postulated accidents are not increased. Therefore, 
there is no undue risk to public health and safety as a result of the 
exemption.

[[Page 74959]]

Consistent With Common Defense and Security

    The proposed exemption, as set forth above, would only affect the 
radiological dose analysis models and the way containment leak-
tightness is measured. Thus, this exemption bears 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)(ii), 
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 Appendix J is to assure that containment leak-
tight integrity is maintained as tight as reasonably achievable, and 
sufficiently tight so as to limit effluent release to values bounded by 
the analyses of radiological consequences of design-basis accidents. 
The NRC staff has determined that the intent of the rule is not 
compromised by the licensee's proposed action because containment leak 
rates will continue to be limited by MNGP's Technical Specifications. 
Therefore, since the underlying purpose of Appendix J is achieved, the 
special circumstances required by 10 CFR 50.12(a)(2) for the granting 
of an exemption from Appendix J 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 public health and safety, and is consistent with the common 
defense and security. Also, special circumstances are present. 
Therefore, the Commission hereby grants MNGP an exemption (1) From the 
requirements of 10 CFR Part 50, Appendix J, Option B, Paragraph III.A, 
to allow exclusion of the main steam pathway leakage from the overall 
integrated leakage rate measured when performing a Type A test; and (2) 
from the requirements of 10 CFR Part 50, Appendix J, Option B, 
Paragraph III.B, to allow exclusion of the main steam pathway leakage 
from the combined leakage rate of all penetrations and valves subject 
to Type B and C tests.
    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 (71 FR 70996).
    This exemption is effective upon issuance.

    Dated at Rockville, Maryland, this 7th day of December, 2006.

    For the Nuclear Regulatory Commission.
Cathy Haney,
Director, Division of Operating Reactor Licensing, Office of Nuclear 
Reactor Regulation.
[FR Doc. E6-21152 Filed 12-12-06; 8:45 am]
BILLING CODE 7590-01-P