[Federal Register Volume 60, Number 194 (Friday, October 6, 1995)]
[Notices]
[Pages 52431-52432]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-24895]



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NUCLEAR REGULATORY COMMISSION

[Docket No. 50-302]


Exemption; Florida Power Corporation, Crystal River Nuclear 
Generating Plant Unit 3

I

    Florida Power Corporation (the licensee) is the holder of Facility 
Operating License No. DPR-72, which authorizes operation of the Crystal 
River Nuclear Generating Plant Unit 3 (CR-3). The license provides, 
among other things, that the licensee is subject to all rules, 
regulations, and orders of the Commission now or hereafter in effect.
    The facility is of a pressurized water reactor type and is located 
in Citrus County, Florida.

II

    Pursuant to Title 10 Code of Federal Regulations Part 50 (10 CFR 
50), Appendix A, ``General Design Criteria for Nuclear Power Plants,'' 
Criterion 16, ``Containment design,'' ``Reactor containment and 
associated systems shall be provided to establish an essentially leak-
tight barrier against the uncontrolled release of radioactivity to the 
environment and to assure that the containment design conditions 
important to safety are not exceeded for as long as postulated accident 
conditions require.'' 10 CFR 50.54(o) states that ``Primary reactor 
containments for water cooled power reactors shall be subject to the 
requirements set forth in Appendix J to this part.'' 10 CFR 50, 
Appendix J, sets forth requirements for periodic verification by tests 
of the leak-tight integrity of the primary reactor containment and 
establish the acceptance criteria for such tests to satisfy general 
design criterion 16 of the Commission's regulations. 10 CFR 50, 
Appendix J, Paragraph III.D.1, specifies a set of three integrated leak 
rate tests (ILRT or Type A test) to be performed at approximately equal 
intervals during each 10-year service period. Such tests are to be 
limited to periods when the plant is non-operational and secured in the 
shutdown condition under an administrative control and in accordance 
with the safety procedures defined in the license.
    For CR-3, the next available opportunity for performing the ILRT 
would be in spring 1996. The licensee requested a one-time interval 
extension for the ILRT by approximately 24 months from the spring 1996 
refueling outage to the spring 1998 refueling outage. The licensee 
indicated that approval of its request would save over two million 
dollars and reduce personnel radiation exposure. An exemption from 10 
CFR 50, Appendix J, Paragraph III.D.1, is needed to permit the licensee 
to defer the ILRT.
    By letter dated May 19, 1995, as supplemented August 8, 1995, the 
licensee submitted its exemption request for this purpose.

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 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 underlying purpose of 10 CFR 
50, Appendix J, Paragraph III.D.1., is to assure that periodic 
surveillance of reactor containment penetrations is performed so that 
proper maintenance and repairs are made during the service life of the 
containment, and leakage through the primary reactor containment shall 
not exceed allowable leakage rate values as specified in the technical 
specifications (TS) or associated bases.

IV

    In support of its exemption request, the licensee submitted 
information pertaining to Type A, and local leak rate (LLRT or Types B 
and C) testing history, structural capability, and risk assessment to 
demonstrate that the proposed exemption would not present an undue risk 
to the public health and safety and would be consistent with the common 
defense and security, and would be authorized by law. The licensee 
indicates that the Type A testing frequency of Appendix J is not 
necessary to achieve the underlying purpose of the regulation and thus 

[[Page 52432]]
special circumstances required by 10 CFR 50.12(a)(2)(ii) apply to this 
situation.
    The CR-3 containment is a reinforced concrete structure with a 
cylindrical wall, a flat foundation mat, and a shallow dome roof. The 
cylinder wall is prestressed with a post-tensioning system in the 
vertical and horizontal directions. The dome roof is prestressed using 
a three-way post-tensioning system. The inside surface of the 
containment has a carbon steel liner to ensure a high degree of leak-
tightness during operating and accident conditions. The liner is 
anchored to the concrete to ensure composite action with the concrete 
shell. Piping penetrations have been designed to ensure that the liner 
would not be breached due to rupture of any process pipe. The 
containment is designed with an allowable leakage rate of 0.25% of 
containment air weight per day (La) at the calculated maximum 
allowable containment pressure (Pa) of 54.2 psig resulting from 
the limiting design basis accidents.
    The historical Type A test results as set forth in the exemption 
request demonstrate that CR-3 has a low-leakage containment. The 
current 10-year inservice inspection and inservice testing service 
period is the second service period and started in March 1987 and ends 
in March 1997. During this service period, the licensee performed one 
ILRT in November 7, 1991. A prior ILRT conducted in November 1987 was 
counted as the third test of the first 10-year interval and therefore, 
the licensee did not take credit for the November 1991 test for the 
current interval. These two ILRTs which have been performed during the 
last seven years have shown acceptable containment leakage rates. There 
have been no permanent or temporary modifications to the containment 
structure, liner or penetrations since the last two Type A tests, and 
no future modifications are planned prior to the 1998 refueling outage 
that could adversely affect the Type A test results.
    The licensee will continue to be required to conduct the Type B and 
C local leak rate tests, which are in general the principal means of 
detecting containment leakage paths, with the Type A tests confirming 
the Type B and C test results. Types B and C testing history at CR-3 
shows that the overall combined as-found leakage has been less than the 
allowed combined leakage rate of 0.6 La (266,431 SCCM) at the 
calculated maximum peak containment pressure as specified in Appendix 
J. Successful performance of Types B and C testing demonstrates the 
leak-tightness of the penetrations and associated components and 
provides a high degree of assurance that the overall Type A leakage 
rate would remain satisfactory while this exemption is in effect. The 
licensee has stated that it will perform the general containment 
inspection, although it is required by Appendix J (Section V.A.) to be 
performed only in conjunction with Type A tests. The NRC staff 
considers that these inspections, though limited in scope, provide an 
important added level of confidence in the continued integrity of the 
containment boundary.
    The purpose of containment leak testing is to detect containment 
leakage which could be the result of failures (active or passive) 
before an accident occurs. Containment leakage caused by degradation of 
sealing material within containment penetrations and containment 
isolation components will continue to be effectively measured by the 
Type B and C testing programs. The Type A tests are only confirmatory 
of the results of the Type B and C test results. The only potential 
failures not covered by Types B and C testing are failures of the 
containment due to structural deterioration because of parameters such 
as pressure or temperature. However, structural deterioration would 
require longer than the proposed period for the exemption.
    There are no mechanisms that would adversely affect the structural 
capability of the containment, which is the only leakage mode not 
captured by the Type B and C testing that will be performed. Absent 
actual accident conditions, structural deterioration of containment due 
to temperature, radiation, chemical, or other such effects is a gradual 
phenomenon requiring periods of time well in excess of the proposed 
interval extension and is subject to detection by periodic visual 
inspections. At CR-3, there has been no evidence of structural 
deterioration that would impact structural integrity or leak tightness. 
Other than postulated accident conditions, the only over-pressure 
challenge to containment is the integrated leak rate test itself. Thus, 
there is significant assurance that the extended interval between Type 
A tests in concert with Type B and C testing will continue to provide 
adequate verification of the leak tight integrity of the containment. 
The proposed one-time change in Type A leakage test frequency only 
affects the length of time that the containment could be in an 
undetected failed state as a result of a failure. As part of the CR-3 
Individual Plant Examination (IPE) program, the risk of losing 
containment integrity is considered negligible compared to other risks 
such as those resulting from small break loss of coolant accidents or 
station blackout.
    Draft NUREG-1493, which provides the technical justification for 
the ongoing Appendix J rulemaking effort (including a 10-year test 
frequency), has shown that essentially all containment leakage can be 
detected by LLRTs (Type B and C). According to results given in NUREG-
1493, only 5 ILRT failures out of 180 ILRT reports that covered 110 
individual reactors and approximately 770 years of operating history, 
were found that local leak rate testing could not have detected. 
Therefore, it is unlikely that this one-time exemption for the 
performance of Type A testing at CR-3 would result in significant 
degradation of the overall containment integrity.
    In summary, the testing history, structural capability of the 
containment, and the risk assessment discussed previously establish 
that (1) CR-3 has had acceptable containment leakage rate test results, 
(2) the structural integrity of containment is assured, and (3) there 
is negligible risk impact in changing the Type A test schedule on a 
one-time basis.
    Therefore, application of the regulation in this particular 
circumstance would not serve, nor is it necessary to achieve, the 
underlying purpose of the rule, and the exemption request meets the 
requirements of 10 CFR 50.12.
    Accordingly, the Commission has determined that, pursuant to 10 CFR 
50.12(a), an exemption is authorized by law, will not endanger life or 
property or common defense and security, and is otherwise in the public 
interest. Therefore, the Commission hereby grants Florida Power 
Corporation a one-time exemption from those requirements of 10 CFR 50, 
Appendix J, relating to containment overall leak rate test and allows 
deferring the performance of a Type A test from the spring 1996 to the 
spring 1998 refueling outage, provided that the general containment 
inspection is performed during the spring 1996 outage. Pursuant to 10 
CFR 51.32, the Commission has determined that the granting of this 
exemption will not result in any significant adverse environmental 
impact (60 FR 46320).

    Dated at Rockville, Maryland, this 29th day of September 1995.

    For the Nuclear Regulatory Commission.
Steven A. Varga,
Director, Division of Reactor Projects--I/II, Office of Nuclear Reactor 
Regulation.
[FR Doc. 95-24895 Filed 10-5-95; 8:45 am]
BILLING CODE 7590-01-P