Information Notice 1985-71, Containment Integrated Leak Rate Tests
SSINS No.: 6835 IN 85-71
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF INSPECTION AND ENFORCEMENT
WASHINGTON, D.C.
20555
August 22, 1985
IE INFORMATION NOTICE NO. 85-71:
CONTAINMENT INTEGRATED LEAK RATE TESTS
Addressees
All nuclear power reactor facilities holding an operating license (OL) or a
construction permit (CP).
Purpose
This information notice is provided as a notification of a potentially signifi- cant problem pertaining to containment integrated leak rate tests (CILRTs).
It
is expected that recipients will review the information for applicability to
their facilities and consider actions, if appropriate, to preclude a similar
problem occurring at their facilities.
However, the suggestion contained in
this information notice (namely, that licensees review their programs with
respect to the guidelines provided), does not constitute an NRC requirement.
Therefore, no specific action or written response is required.
Description of Circumstances
Recent staff reviews of the CILRTs performed at San Onofre, Kewaunee, and
Monticello nuclear power plants have indicated that many utilities are misin- terpreting the relationship between local leak rate testing and CILRTs. 10 CFR
50, Appendix J, discusses containment leakage testing in terms of Type A, B,
and C tests.
The Type A test is a measurement of the overall integrated
leakage rate of the primary containment; whereas Type B and C tests are local
leak rate tests designed to detect and measure local leakage across each
pressure-containing or leakage-limiting boundary for primary containment.
As a result of Type B and C tests, some utilities are performing repairs and
adjustments before conducting Type A tests without properly adjusting the Type
A test results for the Type B and C leakage rates. Without this adjustment, the "as found" condition of the primary containment cannot be properly determined.
In some cases, when this adjustment is made properly, a Type A test may fail to
meet the acceptance criteria of Apprndix J with regards to the "as found"
condition.
When two successive Type A test failures occur, Appendix J requires
more frequent CILRTs.
However, if Type B and C leakage rates constitute an
identified contributor to this failure of the "as found" condition for the
CILRT, the general purpose of maintaining a high degree of containment integrity
might be better served through an improved maintenance and testing program for
8508200623
IN 85-71 August 22, 1985 containment penetration boundaries and isolation valves.
In this situation, the licensee may submit a Corrective Action Plan with an alternative leakage
test program proposal as an exemption request for NRC staff review.
If this
submittal is approved by the NRC staff, the licensee may implement the corrective
action and alternative leakage test program in lieu of the required increase in
Type A test frequency incurred after the failure of two successive Type A
tests.
Discussion:
Sections III.D.1.a, 2.a and 3.a of Appendix J require that a set of three
periodic Type A tests be performed at approximately equal intervals during each
10-year service period, and that Type B and C tests be performed during reactor
shutdown for refueling but in no case at intervals greater than 2 years.
Under
these test requirements, there are many occasions when Type A, B, and C tests
must be performed during the same reactor shutdown period.
Questions are
frequently raised concerning the correct sequence of conducting the Type A, B,
and C tests and the potential impact of the results of the Type B and C tests
on the success or failure of a periodic Type A test.
The NRC staff has previously provided partial guidance to utilities on these
questions on an individual case basis with respect to inspection and enforce- ment activities (see Attachment 1).
The staff position on these questions, as
previously employed in inspection and enforcement, may be summarized as
-fo-llows.:- -
1.Section III.A.3 of Appendix J requires that all CILRTs be conducted in
accordance with the provisions of ANSI N45.4-1972.
Paragraph 4.2 of ANSI
N45.4-1972 states that for periodic CILRTs no repairs or adjustments are
to be made to the containment structure prior to conducting the test in
order to disclose the normal state of repair of the containment structure.
2. Type B and C tests may be performed either before the start of or after
completion of the periodic Type A test provided that the pretest require- ments of Paragraph 4.2 of ANSI N45.4-1972 and Section III.A.1.a of Appen- dix J are met; i.e., no repairs or adjustments to the primary containment
boundary are made so that the containment can be tested in as close to the
"as is" condition as practical.
As such, the leakage information obtained
from the "as is" (sometimes called "as found") Type A-test results can be
used to assess the containment condition and its integrity following a
period of plant operation.
3. If repairs or adjustments performed as a result of the Type B and C
testing programs or for any other reasons are made to the primary contain- ment boundary before the Type A test sequence, local leak tests must be
performed on the affected portion of the containment boundary to determine
the minimum pathway leakage rates before and after the repairs or adjust- ments are made.
The minimum pathway leakage would be the smaller leakage
rate of in-series valves tested individually, one-half the leakage rate
IN 85-71 August 22, 1985 for in-series valves tested simultaneously by pressurizing between the
valves, and the combined leakage rate for valves tested in parallel.
The
"as found" Type A test results can then be obtained by adding the differ- ences between the affected minimum path leakage before and after repairs
or adjustments to the overall measured Type A test result. A periodic
Type A test would be called a "failure" if the "as found" Type A test
result (with appropriate correction from local leak tests) exceeds the
acceptance crtieria of Appendix J.
4. -The question has been raised by various utilities as to how far in advance
of the Type A test the Type B and C tests may be conducted without having
to add the leakage differences to the Type A test results.
The staff
position on this question has been that after Type B and C tests, the
penetrations and valves should experience some period-of normal service
conditions before the Type A test.
If the Type B and C tests are con- ducted before the Type A test during the same refueling outage, the
service condition criterion would not be met.
If, however, some operating
service time is achieved, the Type A test can be conducted essentially
independent of the time duration of exposure to the normal service condi- tions.
Thereafter, a Type A test could be conducted without having to
consider the local leak rate results in determining the "as found"
condition.
The continuance of containment leak-tight integrity is the primary importance
in performing Type A, B, and C tests.
Therefore, it may be beneficial for li- censees to implement improved maintenance and testing programs for containment
penetrations to ensure that known or likely leaking penetrations will not result
in the overall loss of containment leak-tight integrity and in the ensuing
penalties for Type A test failure.
It should also be noted that containment leak-tight integrity is monitored
between CILRTs through the Type B and C test programs.
Failure to meet the
acceptance criteria of Appendix J for those tests generally constitutes a loss
of containment integrity as defined in the Technical Specifications and may be
reportable by the licensee under the provisions of 10 CFR 50.73., Sections
(a)(2)(ii) and (a)(2)(v)(C).
It is suggested that licensees review their CILRT program with respect to the
above guidelines.
IN 85-71 August 22, 1985 No specific action or written response is required by this information notice;
however, if you have any questions regarding this notice, please contact the
Regional Administrator of the appropriate NRC regional office or the technical
contacts listed below.
ar.
/ardan, rec or
Division 10 Emergency Preparedness
and Enineering Response
Office of Inspection and Enforcement
Technical Contacts: Y. S. Huang, NRR
(301) 492-9493
0. C. Kirkpatrick, IE
(301) 492-4510
S. A. McNeil, IE
(301) 492-9602 Attachments:
1. Documentation from NRC to Utilities, Related to Repairs and
Adjustments Done Prior to Type A Tests
2. -List of-Recently Issued IE Information Notices
Attachment 1
IN 85-71 August 22, 1985 Documentation from NRC to Utilities, Related to
Repairs and Adjustments Done
Prior to Type A Tests
1.
Letter to Consumers Power Company from R. L. Spessard, "Big Rock Point
CILRT Schedule," February 3, 1983 This letter informed the licensee of the necessity to increase the CILRT
frequency because of the failure of two consecutive Type A tests conducted
in 1977 and 1982.
During the 1982 refueling outage, Type B and C tests
were conducted and several valves were found to leak excessively and were
repaired.
Subsequently the Type A test was conducted and the licensee
reported a successful test, but it did not include the initial Types B and
C leakage in the Type A test results.
The NRC staff reviewed the tests
and determined that the Type B and C leakage should be added to the Type
A test results, because the plant had not been in service between the time
of the Type B and C tests and the Type A test.
With the addition of the
Type B and C leakage to the Type A test result, the leakage was excessive
and the containment was deemed to have failed the "as found" test
condition.
2.
Letter to Commonwealth Edison Company from R. L. Spessard, "Quad Cities
Unit 1 Containment Integrated Leak Rate Test Frequency," October 7, 1983.
This letter also informed the licensee of the necessity to increase the
CILRT frequency because of the failure of two consecutive Type A tests.
These tests were conducted in 1979 and 1982.
Type B and C tests conduct- ed during the 1982 refueling outage, prior to the Type A test, showed that
the combined leakage from several valves exceeded the allowable Technical
Specification. In addition, the seal between the drywell head and the
drywell vessel flange was found to be leaking to such an extent that the
leakage could not be measured. The licensee repaired these leaks and then
conducted a Type A test that showed the leakage to be within the allowable
limits.
The NRC staff, however, determined that the containment had
failed the CILRT with respect to the "as found" condition.
This determi- nation was based on the position that the Type B and C test results could
be excluded from the "as found condition" only if
some period of normal
station service existed between Type B and C tests and the Type A test.
3.
Inspection Report No. 50-305/84-19 (DRS), Kewaunee, November 27, 1984 and
Notice of Violation to Wisconsin Public Service Corporation -
Docket No.
50-305, November 28, 1984.
Attachment 1
IN 85-71 August 22, 1985 The inspection report discusses an exemption to Appendix J issued to
Wisconsin Public Service Corporation by the NRC.
The exemption permitted
Type B and C tests and repair work on penetrations to be performed at
Kewaunee before Type A tests were conducted.
The exemption required that
leakage reduction caused by the repairs be added to the Type A test result
for the purpose of evaluating the "as found" condition.
The licensee then
wrote to the NRC stating that it did not believe that an exemption was
required to perform Types B and C tests before performing a Type A test.
The licensee based this on the belief that Type A testing and Type B and
C testing were two separate events performed on two separate schedules.
In 1984, the licensee performed Type B and C tests before performing the
Type A test and failed to add the pre- and post-repair differential
leakage to the "as found" Type A test results in its CILRT report. As
stated in the inspection report, the NRC staff did not agree with the
licensee's position because Type B and C testing (with repair) would
invalidate part of the purpose of the Type A test (that is, to establish
the "as found" condition).
As a result, the notice of violation covering
this failure was issued on November 28, 1984.
4.
Inspection Report No. 50-206/85-12 San Onofre Unit 1, April 5, 1985.
Paragraph 6 of this report discusses the results of the CILRT performed at
-San -Onofre-during 1985.
Type C testing and repair work was performed on
six sets of valves just before the Type A test was conducted.
However, differential leakage resulting from the repair was not added to the Type A
test results reported.
As a result a notice of violation covering this
failure is under consideration.
Attachment 2
August 22, 1985
LIST OF RECENTLY ISSUED
IE INFORMATION NOTICES
Information
Date of
Notice No.
Subject
Issue
Issued to
85-70
85-69
85-68
85-42 Rev. 1
85-67
85-66
85-65
85-64
85-63
Teletherapy Unit Full
Calibration And Qualified
Expert Requirements (10 CFR
35.23 And 10 CFR 35.24)
Recent Felony Conviction For
Cheating On Reactor Operator
Requalification Tests
Diesel Generator Failure At
Calvert Cliffs Nuclear
Station Unit 1
Loose Phosphor In Panasonic
800 Series Badge Thermo- luminescent Dosimeter (TLD)
Elements
8/15/85
8/15/85
8/14/85
8/12/85 Valve-Shaft-To-Actuator Key
8/8/85
May Fall Out Of Place When
Mounted Below Horizontal Axis
All material
licensees
All power reactor
facilities holding
All power reactor
facilities holding
Materials and fuel
cycle licensees
All power reactor
facilities holding
All power reactor
facilities holding
All PWR facilities
All power reactor
facilities holding
All power reactor
facilities holding
Discrepancies Between
As-Built Construction
Drawings And Equipment
Installations
Crack Growth In Steam
Generator Girth Welds
BBC Brown Boveri Low-Voltage
K-Line Circuit Breakers, With
Deficient Overcurrefit Trip
Devices Models OD-4 and 5 Potential for Common-Mode
Failure of Standby Gas Treat- ment System on Loss of Off- Site Power
8/7/85
7/31/85
7/26/85
7/25/85 OL = Operating License
CP = Construction Permit