[Federal Register Volume 65, Number 56 (Wednesday, March 22, 2000)]
[Notices]
[Pages 15373-15374]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-7100]


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NUCLEAR REGULATORY COMMISSION

[Docket Nos. 50-260, 50-296 ]


Tennessee Valley Authority; (Browns Ferry Nuclear Plant Units 2 
and 3; Exemption

I

    The Tennessee Valley Authority (TVA or the licensee) is the holder 
of Facility Operating License No. DPR-52 for operation of the Browns 
Ferry Nuclear Plant Unit 2 (BFN-2) and DPR-68 for Unit 3 (BFN-3). The 
licenses provide, among other things, that the licensee is subject to 
all rules, regulations, and orders of the U.S. Nuclear Regulatory 
Commission (Commission or NRC) now or hereafter in effect.
    BFN-2 and BFN-3 are boiling-water reactors located in Limestone 
County, Alabama.

II

    Title 10 of the Code of Federal Regulations (10 CFR), Section 
50.54(o), requires that primary reactor containments for water-cooled 
power reactors be subject to the requirements of Appendix J to 10 CFR 
Part 50.

[[Page 15374]]

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, Section III.A requires that the overall 
integrated leak rate must not exceed the allowable leakage (La) with 
margin, as specified in the Technical Specifications (TS). The overall 
integrated leak rate, as specified in the 10 CFR Part 50, Appendix J 
definitions, includes the contribution from main steam isolation valve 
(MSIV) leakage. By letter dated September 28, 1999, as supplemented by 
letter dated February 4, 2000, 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.
    Option B, Section III.B of 10 CFR Part 50, Appendix J 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 TS. The licensee also requests exemption from this 
requirement, to permit exclusion of the MSIV contribution to the sum of 
the Type B and Type C tests.
    The MSIV leakage effluent has a different pathway to the 
environment. It is not directed into the secondary containment and 
filtered through the standby gas treatment system as is other 
containment leakage. Instead, the MSIV leakage is directed through the 
main steam drain piping into the condenser and is released to the 
environment as an unfiltered ground level effluent. The licensee 
analyzed the MSIV leakage pathway for the increased leakage (from 46 
scfh to 168 scfh), and the containment leakage pathway separately in a 
dose consequences analysis. The calculated radiological consequences of 
the combined leakages were found to be within the criteria of 10 CFR 
part 100 and GDC-19. The staff reviewed the licensee's analyses and 
found them acceptable as described in a safety analysis accompanying 
amendments 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 BFN-2 and BFN-3 containment leakage testing program will be made 
more consistent with the limiting assumptions used in the associated 
accident consequences analyses. The amendments associated with this 
exemption will revise Technical Specification Surveillance Requirement 
3.6.1.3.10 to limit the maximum allowable combined MSIV leakage to 150 
scfm, which is less than the analytical limit of 168 scfm. Therefore, 
the staff finds the proposed exemptions from Appendix J to separate 
MSIV leakage from other containment leakage to be acceptable.

III

    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 
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 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 staff has determined that the intent of the rule is not compromised 
by the proposed action.

IV

    Accordingly, the Commission has determined that, pursuant to 10 CFR 
part 50.12, an exemption is authorized by law and will not present an 
undue risk to the public health and safety, and that there are special 
circumstances present, as specified in 10 CFR 50.12(a)(2). An exemption 
is hereby granted from the requirements of Sections III.A and III.B of 
Option B of Appendix J to 10 CFR part 50. The exemption allows 
exclusion of MSIV leakage from the overall integrated leak rate test 
measurement and from the sum of Type B and C test measurements used to 
determine compliance with TS surveillance requirements for containment 
integrity.
    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 (65 FR 10844).
    This exemption is effective upon issuance and will be implemented 
prior to startup of Cycle 12 for Browns Ferry Unit 2 and prior to 
startup of Cycle 10 for Browns Ferry Unit 3.

    Dated at Rockville, Maryland this 14th day of March 2000.

    For the Nuclear Regulatory Commission.
John A. Zwolinski,
Director Division of Licensing Project Management, Office of Nuclear 
Reactor Regulation.
[FR Doc. 00-7100 Filed 3-21-00; 8:45 am]
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