[Federal Register Volume 70, Number 55 (Wednesday, March 23, 2005)]
[Pages 14734-14735]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-5679]



[Docket No. 50-271]

Entergy Nuclear Vermont Yankee, LLC and Entergy Nuclear 
Operations, Inc. Vermont Yankee Nuclear Power Station; Exemption

1.0 Background

    Entergy Nuclear Vermont Yankee, LLC and Entergy Nuclear Operations, 
Inc. (Entergy or the licensee) are the holders of Facility Operating 
License No. DPR-28 which authorizes operation of the Vermont Yankee 
Nuclear Power Station (VYNPS). 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.
    The facility consists of a boiling-water reactor located in Vernon, 

2.0 Request/Action

    Title 10 of the Code of Federal Regulations (10 CFR), section 
50.54(o), requires primary reactor containments for water-cooled power 
reactors to be subject to the requirements of Appendix J to 10 CFR part 
50. 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 titled ``Performance-Based 
Requirements.'' Option B, section III.A., ``Type A Test,'' requires 
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 leakage rate, as specified 
in the 10 CFR part 50, Appendix J, Option B, definitions, means the 
total leakage rate through all tested leakage paths. The licensee is 
requesting a permanent exemption from Option B, section III.A., 
requirements to permit exclusion of the main steam pathway leakage 
contributions from the overall integrated leakage rate Type A 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 that the sum of the leakage rates of all Type B and 
Type C local leak rate 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 main steam leakage effluent has a different pathway to the 
environment, when compared to a typical containment penetration. It is 
not directed into the secondary containment and filtered through the 
standby gas treatment system as is other containment leakage. Instead, 
the main steam leakage is collected and treated via an alternative 
leakage treatment (ALT) path having different mitigation 
    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). The 
proposed exemption would more appropriately permit ALT pathway leakage 
to be independently grouped with its unique leakage limits. In this 
manner, the VYNPS containment leakage testing program will be made more 
consistent with the limiting assumptions used in the associated 
accident consequence analyses.
    The licensee has analyzed the main steam leakage pathway (with an 
increase in leakage from 62 standard cubic feet per hour (scfh) to 124 
scfh at

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the calculated peak containment internal pressure (Pa)), the secondary 
containment bypass leakage pathways, and the containment leakage 
pathway (La) separately in their dose consequence analyses. The 
calculated radiological consequences of the combined leakages are 
within the criteria of 10 CFR 50.67. The NRC staff reviewed the 
licensee's analyses and found them acceptable.

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 and 
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 part 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. * * *''
    The licensee's exemption request was submitted in conjunction with 
a TS amendment application to increase the allowable leak rate for the 
main steam isolation valves (MSIVs). The proposed amendment will be 
issued concurrently with this exemption. The exemption and amendments 
together would implement the recommendations of Topical Report NEDC-
31858, ``BWR Report for Increasing MSIV Leakage Rate Limits and 
Elimination of Leakage Control Systems.'' The topical report was 
evaluated by the NRC staff and accepted in a safety evaluation dated 
March 3, 1999. The special circumstances associated with MSIV leakage 
testing are fully described in the topical report. These circumstances 
relate to the monetary costs and personnel radiation exposure involved 
with maintaining MSIV leakage limits more restrictive than necessary to 
meet offsite dose criteria and control room habitability criteria.
    The underlying purpose of the rule which implements Appendix J 
(i.e., 10 CFR 50.54(o)) 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. 
The NRC staff has determined that the intent of the rule is not 
compromised by the proposed action.
    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 consequences analyses 
address these pathways as individual factors, exclusive of the primary 
containment leakage. Therefore, the NRC staff finds the proposed 
exemption from Appendix J to be acceptable.

4.0 Conclusion

    Accordingly, the Commission has determined that, pursuant to 10 CFR 
part 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 Entergy an exemption from the 
requirements of sections III.A and III.B of Option B of Appendix J to 
10 CFR part 50 for VYNPS.
    Pursuant to 10 CFR 51.32, the Commission has determined that the 
granting of this exemption will have no significant impact on the 
quality of the human environment (69 FR 67612).
    This exemption is effective upon issuance.

    Dated at Rockville, Maryland, this 17th day of March 2005.

    For the Nuclear Regulatory Commission.
Ledyard B. Marsh,
Director, Division of Licensing Project Management, Office of Nuclear 
Reactor Regulation.
[FR Doc. 05-5679 Filed 3-22-05; 8:45 am]