[Federal Register Volume 60, Number 228 (Tuesday, November 28, 1995)]
[Notices]
[Pages 58686-58688]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-28978]
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NUCLEAR REGULATORY COMMISSION
[Docket Nos. 50-295 and 50-304]
In the Matter of: 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.B and III.D.2.(a) of 10 CFR Part 50, Appendix J,
Option A, require that Type B local leakage 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. In
addition, Sections III.C and III.D.3 of 10 CFR Part 50, Appendix J,
Option A, require that Type C local leakage rate periodic tests shall
be performed during each reactor shutdown for refueling, 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
B and C containment leakage 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 leakage rate tested (Type B and C tests)
as required by 10 CFR Part 50, Appendix J, Option A. There were 23
untested pathways in Unit 1 and 18 in Unit 2. In a letter dated August
16, 1995, the licensee requested relief from the requirement to perform
the Type B and C containment leakage rate tests of certain penetrations
and valves in these pathways in accordance with the requirements of
Sections III.B, III.C and III.D of 10 CFR Part 50, Appendix J, Option
A. Continued operation of the Zion units was authorized by a Notice of
Enforcement Discretion (NOED) orally granted on August 15, 1995, until
such time as the staff acted on the exemption requests. The NOED was
granted in writing on August 16, 1995.
If the exemptions the licensee requested in its letter dated August
16, 1995, are granted, the tests, except those for which permanent
exemptions were requested, would be performed: (1) during the fall 1995
Unit 1 refueling outage, or (2) during power operation on Unit 2 prior
to September 15, 1995, or (3) during the Unit 2 refueling outage in the
fall of 1996.
Attachment 1A of the licensee's letter contained one-time schedular
exemption requests and justifications for pathways that can be tested
at power. Although the tests can be performed with the units at power,
time was needed to properly develop and perform the necessary test
procedures. Accordingly, the licensee requested that the Type B and C
testing of the pathways associated with Zion, Unit 2, be deferred, with
final test completion of the affected pathways (as listed in Attachment
1A) prior to September 15, 1995. The tests have been completed on Unit
2. In addition, the licensee requested that the affected penetrations
associated with Zion, Unit 1, be deferred until the completion of its
current refueling outage, which began on September 9, 1995.
Attachment 1B of the licensee's letter also contains one-time
schedular exemption requests and justifications for pathways that can
only be tested with the unit shutdown. The tests of the penetrations
listed in Attachment 1B would be performed during the next cold
shutdown of sufficient duration. In all cases, the testing would be
performed prior to the end of the next refueling outage on each unit.
The refueling outage is currently in progress for Unit 1 and is planned
for the fall of 1996 for Unit 2.
Attachment 2 of the licensee's letter contains permanent exemption
requests and justifications for pathways that cannot satisfy the
requirements of 10 CFR Part 50, Appendix J, Option A, due to system/
penetration design; that is, a test is not feasible, without making
physical plant modifications.
Pathways Listed in Licensee's Attachment 1A
Attachment 1A of the licensee's letter requested temporary,
schedular exemptions for components in the following containment
penetrations:
Units 1 and 2:
P-14, Valve 1(2) RC8045, Nitrogen to the Pressurizer Relief Tank.
Unit 2 only:
P-30, Valve 2AOV-DT9159A, Reactor Coolant Drain Tank to Gas
Analyzer.
For Unit 2, the required tests were completed prior to September
15, 1995.
For Unit 1, the required tests will be performed before startup
from the current refueling outage. The Zion TSs do not require
compliance with containment leakage rate limits during refueling
outages, because there is little risk of an accident occurring which
would release significant amounts of radioactivity. Therefore, the
staff finds acceptable the schedular exemption request to delay the
local leakage rate testing of valve 1 RC8045 until no later than
startup from the current Unit 1 refueling outage.
Pathways Listed in Licensee's Attachment 1B
Attachment 1B of the licensee's letter requested temporary,
schedular exemptions for components in the following containment
penetrations:
Units 1 and 2:
P-60, Valve 1(2)AOV-RV0005, Containment Vent Isolation
P-70, Valve 1(2)SF8767, Refuel Cavity to Purification Pump
P-80, ECCS Relief Valve Header to Pressurizer Relief Tank
P-99, Valve 1(2)SF8787, Purification Pump to Refuel Cavity
Unit 1 only:
P-30, Valve 1AOV-DT9159A, Reactor Coolant Drain Tank to Gas
Analyzer
For Unit 1, the required tests will be performed before startup
from the current refueling outage. The Zion TSs do not require
compliance with containment leakage rate limits during refueling
outages, because there is little risk of an accident occurring which
would release significant amounts of radioactivity. Therefore, the
staff finds acceptable the schedular exemption request to delay the
local leakage rate testing of the Unit 1 components listed above until
startup from the current Unit 1 refueling outage.
For Unit 2, the leakage pathways do not consist of through-valve
leakage paths, but rather leakage paths out of
[[Page 58687]]
containment isolation valves or barriers through or past valve packing,
diaphragms, flanges, or other resilient seals. The potential leakage
paths are small or restrictive and are at mechanical joints of flange
and compression fittings, through valve packing, or through cracks or
tears in valve diaphragms. Although none of the penetrations in
question were tested in accordance with the requirements, most of them
were tested during the most recent Type A containment leakage rate test
or by process flow, with either no or minimal leakage. For those
penetrations that were not tested, the leakage path for a significant
leak to occur requires a sequence of events for which the probability
of occurrence during the limited time period of the exemption is low
enough to provide reasonable assurance of no significant increase in
risk to the health and safety of the public. In addition, seismic
qualification of some of the systems, missile protection, and the
isolation valve seal water system all provide additional assurance that
the risk of a significant leak is minimal. For these reasons, the staff
finds that the requested schedular exemption is justified and that it
is acceptable to delay the local leakage rate testing of the Unit 2
components listed above until the next cold shutdown of sufficient
duration for testing, but no later than startup from the next Unit 2
refueling outage, currently scheduled for September 1996.
Pathways Listed in Licensee's Attachment 2
Attachment 2 of the licensee's letter requested permanent
exemptions for components in the following containment penetrations:
Units 1 and 2:
P-14, Valve 1(2) FCV-SA01A, Service Air Supply to Containment
P-19, Valve 1(2) MOV-CC9413A, Component Cooling Water Supply to the
Reactor Coolant Pumps
P-34, Valve 1(2) DW0030, Demineralized Flushing Water to
Containment
P-43, Valve 1(2) LCV-DT1003, Reactor Coolant Drain Tank Pump
Discharge
P-75, Valves 1(2) VC8402A, 1920HCV-VC182, 1(2) VC8402B, 1(2)
VC8403, Chemical and Volume Control to Regenerative Heat Exchanger
P-76, Valve 1(2) VC8480A, Reactor Coolant Loop Fill Header
P-77, Valves 1(2) PP0101, 1(2) PP0102, 1(2) PP0103, 1(2) PP0104,
Penetration Pressurization to Containment Valve Stations
P-88, Valve 1(2) FCV-RV112, Containment Hot Water Supply
P-102, Valve 1(2) AOV-RC8029, Primary Water to the Pressurizer
Relief Tank
Unit 1 only:
P-16, Compression Fittings on Five Reactor Vessel Leak Detection
System Lines
To provide time for additional staff review before granting
permanent exemptions, the staff will consider only schedular exemptions
for these components. Final staff action on these exemption requests
will be taken by December 31, 1995.
The leakage pathways listed above do not consist of through-valve
leakage paths, but rather leakage paths out of containment isolation
valves or barriers through or past valve packing, diaphragms, flanges,
or other resilient seals, except for Penetration P-77, which is
reviewed separately below. The potential leakage paths are small or
restrictive and are at mechanical joints of flange and compression
fittings, through valve packing, or through cracks or tears in valve
diaphragms. Although none of the penetrations in question were tested
in accordance with the requirements, most of them were tested during
the most recent Type A containment leakage rate test or by process
flow, with either no or minimal leakage. For those penetrations that
were not tested, the leakage path for a significant leak to occur
requires a sequence of events for which the probability of occurrence
during the limited time period of the schedular exemption is low enough
to provide reasonable assurance of no significant increase in risk to
health and safety of the public. In addition, seismic qualification of
some of the systems, missile protection, and the isolation valve seal
water system all provide additional assurance that the risk of a
significant leak is minimal. For these reasons, the staff finds that a
schedular exemption is justified and that it is acceptable to delay the
local leakage rate testing of the components listed above (except
Penetration P-77) until final staff action on these exemptions, which
will be taken prior to December 31, 1995.
Penetration P-77
Manual containment isolation valves 1(2) PP0101, 1(2) PP0102, 1(2)
PP0103, 1(2) PP0104, are in four lines that are part of the Penetration
Pressurization (PP) system. There is one valve in each line and it is
open during power operation. The piping associated with the PP system
is seismically supported and missile protected. The valves' primary
post-accident design function is to remain open so that the PP system
can continue to pressurize containment penetrations, such as electrical
penetrations, preventing containment leakage out through those
penetrations. These valves have not been locally leakage rate (Type C)
tested for through-valve leakage. Local leakage rate testing is
conducted with the valves open, with the packing of the four valves
part of the test boundary. The leakage rate from this test is added
into the sum of all local leakage rate tests for comparison to the 0.6
La acceptance criterion. This test was completed with satisfactory
results during refueling outage Z1R13 which ended March 1994 for Unit 1
and during refueling outage Z2R13 which ended April 1995 for Unit 2.
The portion of the PP system that includes these valves is continuously
monitored for leakage, with a high flow condition annunciated in the
control room. Additionally, these valves are tested for seat leakage
during the Type A (integrated leak rate) test.
The post-accident design function of the PP system is to pressurize
components to a pressure greater than Pa, the calculated peak accident
pressure of the containment atmosphere during a design-basis accident,
thereby preventing containment out-leakage. The licensee asserts that
Penetration P-77 and its associated valves are provided with a suitable
alternative to Type C testing due to the leak detection and mitigation
capability of the system. The PP system features which provide that
capability are summarized as follows:
(1) Supply characteristics:
(a) Normal supply: 100 psig air receivers
--passive components
--pressurized greater than or equal to 1.10 Pa (Pa=47 psig)
(b) Backup supplies--high degree of redundancy
--three PP air compressors: safety-related, seismic, auto start
feature, powered from ESF buses
--passive supply from high pressure Nitrogen bottles: safety-related,
seismic
--non-safety-related Instrument Air system;
(2) Leak Detection Capabilities: continuously monitored, main
control board alarms on low pressure and on high flow;
(3) Piping system characteristics: seismically designed, missile
protected;
(4) Operational readiness--TSs maintain:
(a) Required pressure and flow
(b) Availability of supplies (air compressors and Nitrogen) and
emergency power supplies
[[Page 58688]]
(c) Periodic testing requirements for compressors.
This system is required to be operable during Operational Modes 1-4
per the TSs. In addition, the PP system seal pressure is designed to
continuously maintain a nominal pressure of 1.04 Pa during post-
accident conditions. Since this penetration and associated valves are
maintained at a pressure greater than or equal to post-loss-of-coolant
accident containment pressure, containment leakage is unlikely through
this penetration.
Based on the above, the staff finds that a schedular exemption is
justified and that it is acceptable to delay the local leakage rate
testing of the four subject valves in Penetration P-77 until final
staff action is taken on these requests. Final staff action will be
taken by December 31, 1995.
In addition, the Commission will not grant an exemption unless at
least one of the special circumstances, as defined in 10 CFR
50.12(a)(2), are present. One of the special circumstances is that: the
exemption would provide only temporary relief from the applicable
regulation and the licensee has made good faith efforts to comply with
the regulations. The licensee presented the following discussion to
show that the requested exemptions provide only temporary relief and
that the licensee made good faith efforts to comply.
The Requested Exemptions Proved Only Temporary Relief and the
License Made Good Faith Efforts to Comply
As discussed above, the exemption request is for short duration
relative to the discovery of the aforementioned issues (30 days for
Unit 2; completion of the upcoming refueling outage for Unit 1). All
pathways that can be safely tested during reactor power operation
for Unit 2 will be tested within 30 days. Such pathways for Unit 1
will be deferred until entry into Hot Shutdown at the completion of
the upcoming outage (outage begins September 7, 1995). For pathways
that cannot be tested during power operation, testing described in
Attachment 1B will be performed during the next opportunity of
sufficient duration when Unit 1 and Unit 2 are in Mode 5. The
pathways selected for testing will be based upon the expected
duration of the shutdown and the time required to prepare the
pathways for testing. Pathways not tested during a Cold Shutdown
will be tested during subsequent cold shutdowns that may occur prior
to the upcoming refueling outages. In all cases, tests will be
completed by the end of Unit 1 outage scheduled to commence
September 7, 1995 and for Unit 2 prior to the completion of the
September 1996 refueling outage. This meets an additional criterion
for a special circumstance per item (v) of 10 CFR 50.12(a)(2)(v),
i.e., ``The exemption would provide only temporary relief from the
applicable regulation and licensee or applicant has made good faith
efforts to comply with the regulation.'' ComEd believes that testing
to be performed prior to September 15, 1995 for Unit 2 and during
the upcoming refueling outage for Unit 1 demonstrates a good faith
effort.
The exemption request is for a short duration relative to the
discovery of the above issues. On Unit 2, the pathways that could be
safely tested during power operation were tested prior to September 15,
1995. On Unit 1, this exemption allows the deferment of the testing of
these pathways until Unit 1 enters hot shutdown during the current
refueling outage. For pathways that can not be tested during power
operation, the testing described in Attachment 1B will be performed on
Unit 1 prior to the end of its current refueling outage and on Unit 2,
prior to the completion of the refueling outage currently scheduled to
commence in September 1996. The staff has decided that a good faith
effort on the part of the licensee to comply with the regulations has
been demonstrated by the testing that has already been completed on
Unit 2, the testing that will be completed on Unit 1 prior to startup
from its current refueling outage, and the schedule for completion of
the remainder of the testing.
IV.
Sections III.B and III.D.2.(a) of 10 CFR Part 50, Appendix J,
Option A, require that Type B local leakage 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. In
addition, Sections III.C and III.D.3 of 10 CFR Part 50, Appendix J,
Option A, require that Type C local leakage rate periodic tests shall
be performed during reactor shutdown for refueling, but in no case at
intervals greater than 2 years.
The licensee proposes an exemption to these sections which would
provide relief from the requirement to perform the Type B and C
containment leakage rate tests of certain penetrations and valves in
accordance with the requirements of Sections III.B, III.C, and III.D of
10 CFR Part 50, Appendix J, Option A.
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, for the reasons
discussed above, that special circumstances, as provided in 10 CFR
50.12(a)(2)(v), are present justifying the exemption; namely, that the
exemption would provide only temporary relief and the licensee made
good faith efforts to comply.
Based on its review of the licensee's justifications, the staff
finds the licensee's requests for schedular exemptions for Type B and C
tests of 10 CFR Part 50, Appendix J, Option A, that can be performed
while at power (Attachment 1A to the licensee's letter) and those that
must be performed while shutdown (Attachment 1B to the licensee's
letter) to be acceptable. The staff has reviewed the licensee's
requests for permanent exemptions for components in certain
penetrations. To provide additional time for staff review before
granting permanent exemptions, the staff will at this time grant only
schedular exemptions until final staff action is taken on these
requests for these components. Final staff action on these exemption
requests will be taken prior to December 31, 1995.
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 45499).
This exemption is effective upon issuance and shall expire upon
completion of the Unit 2 refueling outage, currently scheduled to
commence in September 1996.
Dated at Rockville, Maryland, this 20th day of November 1995.
For the Nuclear Regulatory Commission.
Jack W. Roe,
Director, Division of Reactor Projects--III/IV, Office of Nuclear
Reactor Regulation.
[FR Doc. 95-28978 Filed 11-27-95; 8:45 am]
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