ML20136H357
| ML20136H357 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 01/07/1986 |
| From: | Linenberger G, Margulies M, Paris O Atomic Safety and Licensing Board Panel |
| To: | GEORGIA POWER CO. |
| References | |
| CON-#186-678, CON-186-678 84-499-01-OL, 84-499-1-1, 84-499-1-OL, OL, NUDOCS 8601090514 | |
| Download: ML20136H357 (14) | |
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UNITED STATES OF AMERICA
'e NUCLEAR REGULATORY COMMISSION ATOMIC SAFETY AND LICENSING BOARD '86 JM -8 A10:25 Before Administrative Judges: g 00t;m i m .s .u <
Morton B. Margulies, Chairman 3RANQi Gustave A. Linenberger, Jr.
Dr. Oscar H. Paris gpg g g..
. ) Docket Nos. 50-424-0L
.In the Matter of ) 50-425-OL
)
' GEORGIA POWER COMPANY, et al. ) (ASLBP No. 84-499-01-0L)
)
-(Vogtle Electric Generating ) January 7, 1986 Plant, Units 1 & 2) )
)
HEMORANDUM AND ORDER (Ruling on Motion for Summary Disposition of Contention 10.5 re: ASCO Solenoid Valves)
Introduction On July 31, 1985 the Applicants for an operating license for the Vogtle Electric Generating Plant (VEGP) filed a motion for summary disposition of Contention 10.5 pursuant to 10 CFR 2.749. In this contention Joint Intervenors Campaign for a Prosperous Georgia and Georgians Against Nuclear Energ,< challenge the adequacy of the environmental qualification testing performed upon those models of solenoid valves manufactured by the Automatic Switch Company (ASCO) that are to be used to perform safety related functions in the VEGP. On August 26, 1985 the NRC Staff (Staff) filed a response in support of this motion. No response has been received from Joint Intervenors. We dealt with the subject of applicable standards for suninary disposition
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L in our order of October 3,1985 wherein Applicants' motion for sumary 5
l disposition of Joint Intervenors' Contention 8 was addressed. That 4
discussion is not repeated here. We find this matter to be ripe for
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determination and for the reasons set forth below we deny the motion.
I Discussion Pursuant to 10 CFR 50.49 each applicant for an operating license must have a program for environmentally qualifying electrical equipment that is to perform functions important to safety. Such equipment qualification is further addressed in General Design Criteria 1 and 4 of 10 CFR Part 50, App. A and in Sections III, XI and XVII of 10 CFR Part 50, App. B. Environmental qualification serves the purpose of providing assurance that equipment will perform its intended functions when subjected to conditions representative of normal and design basis accident situations during the operating lifetime of a nuclear power plant. Applicants state that four models of ASCO valves to be used in the VEGP fall within the purview of these qualification considerations.
All of these. valve models are electrically operated to control rate and ,
direction of air flow; they serve as control valves for air operated valves and dampers that in turn will perform safety related functions in VEGP.
As admitted, Contention 10.5 cites historical bases for questioning i-t the adequacy of environmental qualification tests performed upon ASCO valves to be used in the VEGP for the purpose of perfonning safety related functions. In support of their contention, Joint Intervenors 1'
cite a 1983 Staff Board Notification (BN 83-128) for the proposition l
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r o-that numerous ASCO valves failed qualification tests performed by Franklin Research Center (FRC). Intervenors state that the Staff cautioned against using ASCO valves in any application where conditions could be more severe than those reported in qualification reports.
Further, Intervenors related valve failure to exposure of the valves to a temperature in excess of 340*F.
Applicants' motion for sumary disposition of July 31, 1985 is accompanied by a statement of alleged material facts for which there are no litigable issues. That statement is supported by affidavits of two affiants who are employed by two of Applicants' contractors (Bechtel Power Corporation and Westinghouse Electric Corporation) and by a proprietary report of Westinghouse that addresses certain aspects of the temperature environment that one model of valve was subjected to during testing. We find the professional qualifications of the two affiants and the technical quality of the Westinghouse report to be satisfactory.
Applicants identified four models of ASCO valves to be used at the VEGP that fall within the purview of 10 CFR 50.49. These are the models numbered as follows: NP 8316, NP 8320, NP 8321 and 206-381-6F. For convenience in the discussions that follow, these model numbers are redesignated A16, A20, A21 and A6F, respectively. The safety functions associated with each valve model are not identified, nor have we determined which valve models control dampers or other valves.
Applicants describe the various tests, test conditions and test results for these valves, pointing out that three distinct testing programs were undertaken: tests by Isomedix, Inc. performed for ASC0; tests performed
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jointly by ASCO and Westinghouse, presumably for the benefit of utilities using Westinghouse supplied reactors with ASCO valves (as in VEGP); and tests performed by the Franklin Research Center on behalf of the Staff. Owing to the somewhat involved history of the testing efforts and the results therefrom, we shall treat each valve model separately in discussing Applicants' infonnation.
Valve A16 The design and performanco characteristics of the A16 valve are described and Applicants state that process valves at the VEGP that are involved in safety related functions and are controlled by A16 valves are so arranged as to perform their safety functions if a loss of air supply were to occur. A similar statement is made regarding some of the other valves. (Comment: it is not clear to the Board whether this statement carries the implication that no type of failure of these valves could prevent the valve or damper being controlled from achieving its desired safe position. The Board will seek a clarification of this matter during the hearing phase of this proceedirq.) In a report dated July 1979 (Isomedix Test Report AQS21678/TR-Rev. A) Isomedix describes the test program to which it subjected model A16 valves and describes the successful test results. (Coment: the number of A16 specimens that were tested is not stated by Applicant.)
In 1980 and 1981, Westinghouse and ASCO jointly tested A16 valves and judged their performance to indicate that the A16s are environmentally qualified. (Comment: the number of A16 specimens tested is not stated by Applicants.) These tests were not without some m
malfunctions, however. One of the valve specimens encountered performance problems, but not until well after completion of the portion of the test period that simulated in-plant operation for one year after a design basis accident. Although the nature of the perfc>mance problem is not described, Applicants state that the one year period is the length of time that such valves are required to operate. (Comment: no justification 'or this statement is made nor do Applicants discuss the likelihood of other specimens perhaps not lasting this long. The Board will seek an explanation of this during the hearing.) Testing of another A16 specimen could not be successfully completed until the operating voltage applied to the valve was increased from 90 volts DC to 125 volts DC. The cause of this behavior was determined to have resulted from moisture that had penetrated the solenoid housing.
Applicants state that other valve specimens having properly sealed solenoid housings did not exhibit this behavior. (Comment: Applicants are silent as to how the applied voltages stated above compare with the the manufacturer's specification and what steps are taken to assure that the A16 specimens to be used in VEGP will have properly sealed solenoid housings. These are also matters about which the Board will require further infont.ation.) Still another A16 specimen, upon disassembly after the completion of successful testing, was found to have a stuck and torn elastomer diaphragm. This was judged not to represent a test failure, since that particular specimen had already completed a 30-day testing period that simulated over eight years of in-plant service after a design basis event, whereas only one year of service is required at
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l VEGP. (Comment: this statement is typical of statements made regarding A20 and A21 as well. Such statements cause the Board to desire further information about two aspects of the matter, namely, the bases for stating what is the required in-plant post accident service lifetime for the valves in question and how Applicants will know with reasonable l assurance at any time during the useful life of the plant that the valves in question will still have the capability to perform as needed subsequent to a design basis event.) Applicants judged the A16 valves to have been environmentally qualified by the Westinghouse /ASCO program.
That program was conducted in accordance with the Institute of Electrical and Electronics Engineers ("IEEE") " Recommended Practices for Seismic Qualification of Class IE Equipment for Nuclear Power Generating Stations"; and IEEE Standard 382-1972, "IEEE Trial-Use Guide for Type Test of Class 1 Electric Valve Operators for Nuclear Power Generating Stations". Additionally, the qualification program was performed in accordance with the rethodology set forth in WCAP-8587, " Methodology for Qualifying Westinghouse WRD-Supplied NSSS Safety-Related Electrical Equipment." In November 1983, the Staff issued to Westinghouse a Safety Evaluation Report accepting the qualification testing methodology and the test results for the A16 valves.
In 1981, the Franklin Research Center also initiated a test program i
for the Staff that tested two A16 valve specimens. Both specimens l
failed to function properly during simulated design basis accident transients. One A16 had been artificially aged; it failed to function between the first and second transients because of an inadequate air i
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i supply. After curing the air supply problem, FRC was able to continue testing until four days of elapsed time into the second transient simulation. (Comment: whether the initial air supply met the manufacturer's specification and why the valve was not tested beyond four days are not stated.) The second A16 had been naturally aged and it stopped cycling between the first and second simulated transients at 6.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> into the test. It bega, to function again at 15.3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> into the test and continued to operate until 25.6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, after which no further cycling could be accomplished. (Comment: Applicants give no explanation for the cause of this behavior.) FRC published the results of these tests in November 1983 (NUREG/CR-3424). As a consequence of i the FRC results, in December 1983 the Staff revoked that portion of the l above-mentioned Safety Evaluation Report relating to the qualification of the A16 valves. In April 1984, the Staff issued IE Information Notice No. 84-23 in which it concluded that for the artificially aged valve specimen, the FRC tests were inconclusive because of the severe preconditioning to which that specimen had been subjected. As to the naturally aged specimen, the Staff concluded that the FRC test results called into question the validity of the prior Westinghouse /ASCO results. Applicants state that the Staff further concluded that the A16s were acceptable for use only where anticipated environmental conditions did not exceed those imposed by the Isomedix tests. In January 1985, the Staff reiterated this conclusion (IE Information Notice No. 85-08) with the further provision that the A16s employ ethylenepropylene(ratherthanViton) elastomers. Applicants state l
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e that both of these conditions will be met for the A16 valves to be used in VEGP. In support of their claim that the Isomedix conditions will be met, Applicants submitted the Westinghouse proprietary report mentioned above. That report (WCAP-8687, Supp. 2-H02A/H05A, Addendum 1, Rev. O, January 1985) documents through a thermal lag analysis that an A16 valve in a post-LOCA containment environment in VEGP will not exceed the temperature reached by these valves in the Isomedix test program.
Applicants state that this analysis has been accepted by the Staff.
Valve A20 The differences in design and functional characteristics of this model of valve that distinguish it from the model A16 valve are discussed. Applicants state that, as with the A16s, air operated process valves (or perhaps dampers) controlled by A20s at VEGp will be so configured as to insure that such process valves will assume a safe position when the A20s are vented. (The Board makes the same observation here, analogous to that made previously in the A16 discussion, namely, that it is not clear whether failure of an A20 can give rise to a potential safety problem; we shall require further infonnation. ) Applicants do not state that any A20 specimens were tested by Isomedix; rather, Applicants rely upon the results of Westinghouse /ASCO and FRC tests for the qualification of the A20s. The former tests were performed to the same specifications during the same time period as for the A16s. No performance ancmalies were cited.
(Comment: Applicants do not state how many A20 specimens were tested by Westinghouse /ASCO.) FRC tested one specimen of the A20, which was artificially aged to simulate four years of in-plant life at 140'F.
This specimen functioned throughout the tests, but subsequent to a design basis accident simulation FRC found that the valve showed seat leakage in excess of 100 cubic feet per hour. Applicants say that the valve continued functioning despite this leakage, since that amount of leakage does not impair the capability of the valve to exhaust incoming air. (Comment: absent information about the manufacturer's specification regarding allowable leakage, this seems almost tantamount to saying that leakage is acceptable so long as it is not unacceptable.)
Applicants state that ASCO calculated 151 cubic feet per hour to be (as the Board understands the affiant's statement) the threshold of unacceptability. (Comment: it is impossible for us to determine from the information before us whether the difference between "in excess of 100 cubic feet per hour" and the manufacturer's calculated 151 cubic 4
feet per hour is a comfortable margin. We shall expect this matter to beexplainedatthehearing.) Based upon the two above-mentioned test program results, the model A20 is considered by Applicants to be environmentally qualified.
Valve A21 The design and functional characteristics of A21 are described by Applicants as being similar to those of A16, the primary differences being that the model A21 is piston operated and has orifices sized to yield a smaller air flow rate than delivered by A16. A21 specimens were subjected to the same three test programs during the same
- time periods noted above for A16. Unlike the two models previously discussed, A21 is not destined for use inside of the VEGP containment; l
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I hence the conditions to which it must be environmentally qualified are less severe.
Isomedix tested one specimen of the A21, which performed successfully throughout the test program under conditions more severe than are required of it for duty outside of the containment. No ,
behavioral anomalies are mentioned by Applicants. These results are reported in the July 1979 Isomedix report previously cited.
Westinghouse /ASCO tested one specimen of the A21, which failed during simulated design basis environmental testing. That failure did not occur until twelve days into the test sequence, which period of time Applicants state simulates one year of post-accident operation in VEGP.
Applicants contrast this performance with the required operation of only l a few hours in VEGP. (We are not told the nature or cause of failure, the manufacturer's specification for duration of operability, nor the basis for Applicants' conclusion that only a few hours of operation is required in VEGP. We shall require more information about these matters atthehearing.)
The FRC tested one specimen of A21, which had been artificially aged to simulate a four year life at 140'F. However, Applicants state that following this aging the A21 was removed from the test program l because it had developed seat leakage in excess of 60 liters per minute.
This was reported by FRC in NUREG/CR-3424. ASCO subsequently calculated that for duty at VEGP an A21 could tolerate up to 380 liters per minute before affecting its operability, a seemingly comfortable margin with l
respect to the leakage actually observed. (Comment: this margin may be l
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meaningless if the A21 leakage were dependent upon the length of time the specimen was left in the test program. Since that question is not addressed in the material submitted by Applicants, we expect it to be resolved at the hearing.) FRC's experience with A21 is not considered to detract from the results of the other two test programs and valve A21 is judged by the Applicants to be environmentally qualified.
Valve A6F The A6F valve is described as a 3-way direct acting solenoid valve having no internal pilot such as is employed in A16. The vaive configurations at VEGP performing safety-related functions that are controlled by A6F valve are said to be arranged so that the process valve (or damper) will attain the desired safe position, either open or closed, if a loss of air supply were to occur. (Again the unanswered question arises as to whether any failure of an A6F can result in unsafe performance of the related process valve.) One each A6F specimen was tested by Westinghouse /ASCO and by FRC; it is not explicitly stated that any A6Fs were tested by Isomedix. Applicants state that the A6Fs performed successfully without anomalous behavior throughout all phases of testing. Thus they are judged by the Applicants to be environmentally qualified.
In its response of August 26, 1985, the Staff supported Applicants' motion for summary disposition of Contention 10.5, casing that support upon the accompanying statement of its affiant, whose qualifications are appropriate to the matters discussed. Staff's affiant provides a summary account of much of the same information provided by Applicants, concurs with Applicants' statement of facts for which there are no i
litigable issues, and concludes that Applicants' motion should be granted.
We find that Applicants' statement of facts does not eliminate all issues of material fact, several of which have been explicitly noted previously. In addition to those noted previously, we consent here upon an additional consideration of concern to us. Affiants for Applicants state that each specimen of each model tested is representative of the models to be used in the VEGP, but the basis for such statements is not provided. The Board observes that if the specimens tested are truly representative, then the anomalous behavior of certain model specimens might well be expected to occur in VEGP specimens. Although each anomaly is stated not to be a source of safety-related concerns, the validity of Joint Intervenors' Contention 10.5 should not be considered without regard to the question of whether there is an adequate basis of assurance that no production specimen of any of these valves used in VEGP will exhibit safety-threatening anomalies. Indeed, we read 10 CFR 50.49(e)(8), headed" Margins",toanticipatejustsuchapotential problem by stating:
Margins must be applied to account for unquantified L uncertainty, such as the effects of production variations and inaccuracies in test instruments. These margins are in addition to any conservatisms applied during the derivation of local environmental conditions of the equip-ment unless these conservatisms can be quantified and shown to contain appropriate margins.
Applicants have not included in the materials supplied with their motion !
an explanation of how or whether such a consideration has been applied f i
l to the matters before us. Thus we find that there is yet another issue I
of material fact to be resolved.
With respect to Intervenors' concern about temperature limitations on valve testing, we find no evidence before us to indicate that temperature exposure at or below that expected to be encountered in VEGP during nonnal or accident conditions is responsible for the malfunction of any model of valve for which environmental tests are accepted.
Having reviewed all of the foregoing, the Board concludes that Applicants' motion for sumary disposition is not dispositive of several issues of material fact inherent in Contention 10.5. These are repeated here:
There is no information offered that permits a determi-nation of whether any type of failure of any of the valve models considered will result in achieving an unsafe configuration for the valves and/or dampers that are being controlled.
No basis is provided for the various statements about how long any of the valve models will be required to operate in VEGP following an accident, nor is there an explanation of how it will be determined that any of the valve models will indeed be capable of the specified length of operating time following an accident.
It cannot be determined whether the unsealed solenoid housing on one A16 valve specimen represents a quality control deficiency that can endanger VEGP operation.
Since no manufacturer's specifications for the various valvemodelsaregiven(e.g.acceptableoperating voltage ranges, air supply requirements and acceptable leak rates) the anomalous behaviors noted are difficult to evaluate as to seriousness. Likewise, the likelihood of valve leakage depending upon the duration of test conditions cannot be evaluated.
The question of whether production models of the valves discussed may show different performance characteristics than did the specimens tested cannot be evaluated, since Applicants have not addressed the subject matter of 10 CFR 50.4g(e)(8) in their motion.
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Thus we have identified five areas of material facts for which genuine issues remain to be heard.
ORDER Owing to the existence of unresolved issues of material fact noted above, the Board denies Applicants' motion for summary disposition of Contention 10.5, and the contention will be litigated as to the issues identified. 1 THE ATOMIC SAFETY AND LICENSING BOARD 2 *='
Morton 8. Mar uliesg Chairman
- 1 ADMINISTRATIV LAW UUDGE 4+sh4%
[Gestave A. LinQfrger, Jr.
ADMINISTRATIVE JtDGE bOAVN Dr. Oscar H. Paris OXb l
ADMINISTRATIVE JUDGE Dated at Bethesda, Maryland this 7th day of January,1986, i
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