United States Nuclear Regulatory Commission - Protecting People and the Environment

Information Notice No. 85-71: 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

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 
significant 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 
misinterpreting 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 if Appendix 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 
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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 
enforcement activities (see Attachment 1). The staff position on these 
questions, as previously employed in inspection and enforcement, may be 
summarized as follows: 

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 
     requirements of Paragraph 4.2 of ANSI N45.4-1972 and Section III.A.1.a 
     of Appendix 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 
     containment 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 adjustments 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 
                                                            Page 3 of 4    

     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 
     differences 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 criteria 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 conducted 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 conditions. 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 licensees 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. 
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                                                            Page 4 of 4 

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. 


                                   Edward L. Jordan Director 
                                   Division of Emergency Preparedness 
                                     and Engineering Response 
                                   Office of Inspection and Enforcement 

Technical Contacts: Y. S. Huang, NRR
                    (301) 492-9493

                    D. 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 
                                                            Page 1 of 2    

              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 
     conducted 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 determination 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 
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                                                            Page 2 of 2 

     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. 
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