[Federal Register Volume 60, Number 32 (Thursday, February 16, 1995)]
[Notices]
[Pages 9059-9060]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-3879]



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NUCLEAR REGULATORY COMMISSION
[Docket Nos. 50-237, 50-249 50-254, 50-265]


Commonwealth Edison Co., Facility Operating License

Exemption

    In the Matter of Commonwealth Edison Co. (Dresden Nuclear Power 
Station, Units 2 and 3; Quad Cities Nuclear Power Station, Units 1 
and 2).

I

    Commonwealth Edison Company (ComEd, the licensee) is the holder of 
Facility Operating License Nos. DRP-19 and DRP-25, which authorize 
operation of Dresden Nuclear Power Station, Units 2 and 3, at a steady 
state power level not in excess of 2527 megawatts thermal; and Facility 
Operating license Nos. DRP-29 and DRP-30, which authorize operation of 
Quad Cities Nuclear Power Stations, Units 1 and 2, at a steady state 
power level not in excess of 2511 megawatts thermal. Dresden Station is 
comprised of two boiling water reactors at the licensee's site located 
in Grundy County, Illinois. Quad Cities Station is comprised of two 
boiling water reactors at the licensee's site located in Rock Island 
County, Illinois. These licenses provide, among other things, that 
Dresden and Quad Cities are subject to all rules, regulations, and 
Orders of the U.S. Nuclear Regulatory Commission (the Commission) now 
or hereafter in effect.

II

    By letter dated October 4, 1994, the licensee requested a revision 
to an exemption from certain Type B (local leak rate) testing 
requirements of appendix J to 10 CFR part 50, for two-ply containment 
penetration expansion bellows at four reactor units. The request was 
made because the licensee has developed a set of alternative approaches 
which can be applied to ensure the intent of requiring a Type A test, 
as part of the original exemption, is met.
    On February 6, 1992, the NRC issued an Exemption from certain Type 
B testing requirements of Appendix J. This exemption stated upon 
completion of the two-ply bellows testing program, a Type A integrated 
leak rate test (ILRT) will be performed to verify primary containment 
integrity. The testing program was intended to assure that at least one 
ply of a two-ply bellows is intact and that overall containment leakage 
is within its allowable limit as shown by Type A testing. The Type A 
test was the only test available that could properly quantify the 
bellows' leakages, albeit not individually. The Exemption also stated 
that if a method is developed which ensures a valid Type B test on one 
or more bellows assemblies, those bellows will also be excluded from 
the Exemption and will be required to be tested in accordance with the 
normal Type B test program.

III

    The original Exemption allowed ComEd to apply special testing 
techniques in lieu of performing a test which meets Type B requirements 
for these bellows which, at that time, were unable to be tested in 
strict conformance to the appendix J criteria. The special testing 
techniques included a sequence of air and helium based local leak rate 
tests (LLRT) for each affected penetration and performance of a Type A 
leak rate test upon completion of the bellows testing during each 
refuel outage.
    Commonwealth Edison Company now believes that the requirement to 
perform a Type A test every outage is not necessary to ensure that the 
bellows assemblies are adequately tested and leakage from any leaking 
bellows assembly is adequately quantified. Through testing of two-ply 
bellows at Dresden Station and Quad Cities Station, the licensee has 
developed the following insights:
    1. There is minimal probability for the occurrence of a large leak 
in a two-ply bellows;
    2. the special testing program is effective for identifying small 
leaks in two-ply bellows;
    3. the Type A test is ineffective for identifying small leaks in 
two-ply bellows; and
    4. more cost effective alternative methods have been developed for 
quantifying leakage.
    At the time of the original request for an exemption, a Type A test 
was required every outage in accordance with the Technical 
Specifications (TS) and appendix J criteria for determination of ILRT 
test frequency. Based on appendix J and the TS, ComEd need not do a 
Type A test every refuel outage if they have completed two consecutive 
successful Type A tests. Quad Cities has completed two consecutive 
successful Type A tests. However, as previously stated the original 
exemption requires a Type A test every outage to support the two-ply 
bellows leakage testing.
    The licensee has discovered very small leaks using the special 
testing techniques in some bellows and they have subsequently been 
modified, removed from the list described in the original exemption and 
are not on a Type B testing schedule.
    The licensee has identified several methods for conducting a valid 
Type B test on bellows since the original Exemption was issued. The 
first method involves the addition of a bellows test enclosure equipped 
with leaktight seals. The second involves installation of a rubber boot 
inside the drywell to form a seal between the drywell atmosphere and 
the bellows. The third is to weld a cover plate inside the drywell to 
provide a seal between the process pipe and the drywell atmosphere. The 
licensee also has the option to implement a complete replacement of the 
existing two-ply bellows assemblies with a new testable two-ply 
bellows.
    The licensee has proposed the following revision to the approved 
exemption for non-Type B testable bellows. This proposal eliminates the 
need but keeps the option to perform a Type A test every refuel outage. 
The licensee proposed to include the following alternatives to the 
current requirement in place of the existing Section III.6 and .7 in 
the original Exemption:

    Upon completion of the two-ply bellows special testing program, 
the following actions shall be taken to address any two-ply bellows 
which have been identified as leaking through both plies:
    (A) All bellows which leak through both plies shall be tested in 
accordance with Type B requirements to ensure license limits are met 
prior to return to service, or
    (B) A Type A ILRT test shall be performed to verify primary 
containment integrity. All two-ply bellows assemblies which 
demonstrate leakage through both plies shall be replaced or 
subjected to a valid Type B test to demonstrate license limits are 
met prior to return to service from the subsequent refuel outage, 
unless ComEd provides justification for continued operation greater 
than one operating cycle.

    The licensee states that the estimated cost of a Type A test, as 
described in NUREG-1493, ``Performance-Based Containment Leak-Test 
Program,'' Draft Revision 2, dated March 31, 1994, is $1.89 million. 
Based on the number of historical leaking bellows found at Dresden and 
Quad Cities during the refuel outages, the cost of the Type A test per 
bellows ranges from $378k to $1.89M. The licensee also states that the 
Type A tests performed every outage since approval of the current 
exemption have never found a bellows leak which was undetected by the 
special testing program. The techniques of the special 
[[Page 9060]] test program have the ability to detect leaks smaller 
than would be detected by the Type A test.
    For a two-ply bellows that leaks through both plies, this revised 
exemption allows: (1) A valid Type B test using one of various 
developed alternatives to ensure compliance to license limits, or (2) a 
Type A test as required in the original exemption and, before the 
return to power in a subsequent refuel outage, replacement of the 
bellows with a testable bellows assembly or a valid Type B test to 
ensure license limits are met.
    The staff finds that the underlying purpose of the regulation will 
be met in that the proposed testing program will detect bellows 
assemblies with significant flaws and result in replacement of flawed 
assemblies within one operating cycle, or be tested with a Type B test 
to ensure license limits are met during which period there is 
reasonable assurance that the bellows assemblies will not suffer 
excessive degradation. If the licensee should propose to wait longer 
than one cycle to replace any bellows assembly, the staff must evaluate 
and approve the request at that time.

IV

    Accordingly, the Commission has determined that, pursuant to 10 CFR 
50.12(a)(i) and (a)(2)(ii), that (1) the Exemption from appendix J 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, and 
(2) application of the regulation in this particular circumstance is 
not necessary to achieve the underlying purpose of its rule.
    The Commission concludes that the testing and replacement program 
for the containment penetration bellows assemblies is an acceptable 
alternative to the existing appendix J testing requirement. 
Accordingly, the Commission hereby grants the Exemption from appendix 
J.
    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 (59 FR 64001).
    This exemption is effective upon issuance.

    Dated at Rockville, Maryland this 9th day of February 1995.

    For the Nuclear Regulatory Commission.
Jack W. Roe,
Director, Division of Reactor Projects III/IV, Office of Nuclear 
Reactor Regulation.
[FR Doc. 95-3879 Filed 2-15-95; 8:45 am]
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