[Federal Register Volume 60, Number 247 (Tuesday, December 26, 1995)]
[Notices]
[Pages 66805-66806]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-31254]
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NUCLEAR REGULATORY COMMISSION
[Docket Nos. 50-295 and 50-304]
Commonwealth Edison Company (Zion Nuclear Power Station, Unit
Nos. 1 and 2)
Exemption
I
Commonwealth Edison Company (ComEd or the licensee) is the holder
of Facility Operating License Nos. DPR-39 and DPR-48, which authorize
operation of the Zion Nuclear Power Station, Unit Nos. 1 and 2, at a
steady-state reactor power level not in excess of 3250 megawatts
thermal. The facilities are pressurized water reactors located at the
licensee's site in Lake County, Illinois. The licenses provide, among
other things, that the Zion Nuclear Power Station is subject to all
rules, regulations, and Orders of the U.S. Nuclear Regulatory
Commission (the Commission or NRC) now or hereafter in effect.
II
Sections III.C and III.D.3 of 10 CFR part 50, appendix J, require
that Type C local leak rate periodic tests shall be performed during
reactor shutdown for refueling, or other convenient intervals, but in
no case at intervals greater than 2 years. These requirements are
reflected in the Zion Technical Specifications (TS) as requirements to
perform type C containment leak rate testing in accordance with 10 CFR
part 50, appendix J, and approved exemptions.
III
The licensee has determined that certain containment isolation
pathways have not been locally leak rate tested (type C tests) as
required by appendix J to 10 CFR part 50. In a letter dated August 16,
1995, the licensee requested relief from the requirement to perform the
type C containment leak rate tests of certain penetrations and valves
in these pathways in accordance with the requirements of sections III.C
and III.D of 10 CFR part 50, appendix J. On August 16, 1995 the staff
authorized in writing, continued operation of the Zion units in a
notice of enforcement discretion (NOED) until such time as the staff
acted on the exemption requests. In a letter dated November 20, 1995,
the staff granted the schedular exemptions requested in the licensee's
letter of August 16, 1995, and granted schedular exemptions for the
permanent exemption requests to allow time for additional staff review
and until final staff action could be taken. In its letter of November
28, 1995, and supplemented on December 6, 1995, the licensee requested
that certain schedular exemption requests be granted as permanent
exemptions.
The licensee's letter of November 28, 1995, requested permanent
exemptions for components in the following containment penetrations:
Units 1 and 2: P-70, Valve 1(2)SF8767, Refuel Cavity to
Purification Pump; P-99, Valve 1(2)SF8787, Purification Pump to Refuel
Cavity.
The licensee's letter of November 28, 1995, also requested that the
following permanent exemption requests be changed to schedular
exemption requests.
Units 1 and 2: P-77, 1(2)PP0101, 1(2)PP0102, 1(2)PP0103, 1(2)PP0104
(Penetration Pressurization to Containment Valve Stations); P-102,
1(2)AOV-RC8029 (Primary Water to the Pressurizer Relief Tank).
For unit 1, the penetrations would be tested during the refueling
outage in the fall of 1995, and for unit 2, they would be tested during
the next cold shutdown of sufficient duration, and subsequently
thereafter as required. For P-77 and P-102, the staff's letter of
November 20, 1995, granted schedular exemptions until December 31,
1995, at which time final action will be taken. This schedular
exemption still applies for units 1 and 2.
The licensee's letter of November 28, 1995, also requested that for
P-44, the permanent exemption request be changed to a schedular
exemption request. In a letter dated December 6, 1995, the licensee
withdrew the previous requests because it intends to test the
penetration in accordance with the requirements of 10 CFR part 50,
appendix J.
The licensee's request dated November 28, 1995, justified the
proposed permanent exemptions for P-70 and P-99 on the following basis.
For P-70 and P-99, the tests were intended to be performed with air
by installing a hole plug to allow a pressure source hookup while
maintaining an adequate pressure boundary. During a walkdown of the
test boundary, it was identified that the design of the piping for
these penetrations does not allow draining of accumulated water in the
line and, therefore, prevents a proper leak rate test with air per the
requirements of 10 CFR part 50, appendix J. The piping configurations
were not known to the licensee when the exemption request dated August
16, 1995, was submitted. For P-70, in addition to not being able to
completely drain the line, the dose rates for the location where the
hole plug would have to be installed are extremely high, on the order
of 1-2 Rem/hour. For P-99, the piping configuration is such that the
location of the test connection would pose a personnel safety issue
since the connection is located on the side of the refueling cavity
approximately 30 feet above the cavity floor. In its submittal dated
November 28, 1995, the licensee, therefore, requested a permanent
exemption to be allowed to perform the test with water. If the
exemptions were approved, dewatering of the lines would not be
necessary, and the isolation for the test boundaries would be by other
means. The test would be performed by pressurizing the subject valve
with water to approximately 100 psig (greater than Pa, which is 47
psig) and inspecting the valve for leakage. The acceptance criterion
will be the same as the other tests which use water as a test medium,
zero leakage.
The leakage pathways for P-70 and P-99 do not consist of through-
valve
[[Page 66806]]
leakage paths, but rather leakage paths out of containment isolation
valves through valve diaphragms. The potential leakage paths are small
or restrictive and are through cracks or tears in valve diaphragms. The
leakage path for a significant leak to occur requires a sequence of
events for which the probability of occurrence is low. The proposed
test, with water as the test medium and with a zero leakage acceptance
criterion, is conservative enough to provide reasonable assurance of no
significant increase in risk to health and safety of the public when
compared to testing with air. In addition, seismic support of the
systems, missile protection, and, for P-70, the isolation valve seal
water system all provide additional assurance that the risk of a
significant leak is minimal.
To justify granting an exemption to the requirements of 10 CFR Part
50, Appendix J, a licensee must show that the requirements of 10 CFR
50.12(a)(1) are met. The licensee stated that its exemption requests
meet the requirements of 10 CFR 50.12(a)(1), for the following reasons:
Criteria for Granting Exemptions are Met per 10 CFR 50.12(a)(1)
1. The requested exemptions and the activities which would be
allowed thereunder are authorized by law.
If the criteria established in 10 CFR 50.12(a) are satisfied, as
they are in this case, and if no other prohibition of law exists to
preclude the activities which would be authorized by the requested
exemption, and there is no such prohibition, the Commission is
authorized by law to grant this exemption request.
2. The requested exemption will not present undue risk to the
public.
As stated in 10 CFR 50, Appendix J, the purpose of primary
containment leak rate testing is to assure that leakage through
primary containment and systems and components penetrating primary
containment shall not exceed the allowable leakage rate values as
specified by the Technical Specifications or associated bases and to
ensure that the proper maintenance and repairs are made during the
service life of the containment and systems and components
penetrating primary containment. The requested exemption is
consistent with this intent for those penetrations in that alternate
means of ensuring leakage remains acceptably low will be performed
as proposed herein.
3. The requested exemption will not endanger the common defense
and security.
The common defense and security are not in any way compromised
by this exemption request.
In addition, the licensee must show that at least one of the
special circumstances, as defined in 10 CFR 50.12(a)(2) is present. One
of the special circumstances that a licensee may show to exist is that
the application of the regulation in the particular circumstance is not
necessary to achieve the underlying purposes of the rule. The purposes
of the rule, as stated in Section I of 10 CFR 50, Appendix J, are to
ensure that: (1) Leakage through the primary reactor containment and
systems and components penetrating containment shall not exceed
allowable values, and (2) periodic surveillance of reactor containment
penetrations and isolation valves is performed so that proper
maintenance and repairs are made. The staff has reviewed the licensee's
proposal and has concluded that the proposed alternative tests will
confirm the integrity of the subject pathways. Therefore, application
of the regulation in this particular circumstance is not necessary to
achieve the underlying purpose of the rule.
IV
Sections III.C and III.D.3 of 10 CFR Part 50, Appendix J, require
that Type C local leak rate periodic tests shall be performed during
reactor shutdown for refueling, or other convenient intervals, but in
no case at intervals greater than 2 years.
The licensee proposes exemptions to these sections which would
provide relief from the requirement to perform the Type C containment
leak rate tests of certain valves in accordance with the requirements
of Sections III.C and III.D of 10 CFR Part 50, Appendix J.
The Commission has determined that, pursuant to 10 CFR 50.12(a)(1),
this 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. The Commission further determined that special
circumstances, as provided in 10 CFR 50.12(a)(2)(ii), are present
justifying the exemption; namely, that the application of the
regulation is not necessary to achieve the underlying purpose of the
rule.
Therefore the Commission hereby grants the following exemption:
The requirement of 10 CFR Part 50, Appendix J, to pressurize the
valves in penetrations P-70 and P-99 with air or nitrogen is not
necessary. Instead, the test pressure medium may be water.
Pursuant to 10 CFR 51.32, the Commission has determined that
granting these exemptions will not have a significant impact on the
human environment (60 FR 63549).
Dated at Rockville, Maryland, this 11th day of December 1995.
For the Nuclear Regulatory Commission.
Jack W. Roe,
Director, Division of Reactor Projects--III/IV, Office of Nuclear
Reactor Regulation.
[FR Doc. 95-31254 Filed 12-22-95; 8:45 am]
BILLING CODE 7590-01-P
