ML20076B649

ECCS Repts (F-47) TMI Action Plan Requirements,Calvert Cliffs Nuclear Power Plants Units 1 & 2, Technical Evaluation Rept

ML20076B649
Person / Time
Site:	Calvert Cliffs
Issue date:	09/24/1982
From:	Ludington B, Overbeck G, Vosbury F FRANKLIN INSTITUTE
To:	Chow E NRC
Shared Package
ML20076B652	List: ML20076B649
References
CON-NRC-03-81-130, CON-NRC-3-81-130, RTR-NUREG-0737, RTR-NUREG-737 TER-C5506-268-2, TER-C5506-268-269, NUDOCS 8209290096
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TECHNICAL EVALUATION REPORT l 1

ECCS REPORTS (F-47)

TMI ACTION PLAN REQUIREMENTS i BALTIM0RE GAS & ELECTRIC COMPANY CALVERT CLIFFS NUCLEAR POWER PLANT UNITS 1 AND 2 1

NRC DOCKET NO. 50-317, 50-318 FRC PROJECT C5506 FRC ASSIGNMENT 7 NRC CONTRACT NO. NRC-03-81 130 FRC TASKS 268, 269 Preparedby F. W. Vosbury Franklin Research Center Author: G. J. Overbeck 20th and Race Streets B. W. Ludington Philadelphia. PA 19103 FRC Group Leader: G. J. Overbeck Prepared for Nuclear Regulatory Commission Lead NRC Engineer: E. Chow Washington, D.C. 20555 September 24, 1982 This report was prepared as an account of work sponsored by an agency of the United States Goverrment. Neither the United States Government nor any agency thereof, or any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for any third party's use, or the results of such use, of any information, appa-ratus, product or process disclosed in this report, or represents that its use by such third l party would not infringe privately owned rights.

1 Prepared by: Reviewed by: Approved by:

,. T _ Yk b l Principal Autho( Croup'Ldader Departrnent Di/ ecto, Date- O*M U Date-Date: 0 ~2b 02 si Franklin Research Center 1%gGgg [

A Division of The Franklin Institute The Benptrun FrankEn Parkwey Phila Pa. 19103 (215)448-1000 XA_ Copy Hcs kon Sept tolk _

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CONTENTS Section Title Page 1 INTRODUCTION . . . . . . . . . . . . . 1 1.1 Purpose of Review . . . . . . . . . . . 1 1.2 Generic Background. . . . . . . . . . . 1 1.3 Plant-Specific Background . . . . . . . . . 2 2 REVIEW CRITERIA. . . . . . . . . . . . . 3 3 TECHNICAL EVALUATION . . . . . . . . . . . 4 3.1 Review of Completeness of the Licensee's Report . . . 4 3.2 Comparison of ECC System Outages with Those of Other Plants. . . . . . . . . 4 3.3 Review of Proposed Changes to Improve the Availability of ECC Equipment . . . . . . . . 9 4 CONCLUSIONS. . . . . . . . . . . . . . 10 5 REFERENCES . . . . . . . . . . . . . . 11 iii A. o. -l;U Franklin Research Center a c>a.on as n. Frerma m.

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TER-C5506-268/269 FoRawoRD This Technical Evaluation Report was prepared by Franklin Research Center under a contract with the U.S. Nuclear Regulatory Commission (Office of ,

Nuclear Reactor Regulation, Division of Operating Reactors) for technical assistance in support of NRC operating reactor licensing actions. The technical evaluation was conducted in accordance with criteria established by the NRC.

Mr. G. J. Overbeck, Mr. F. W. Vosbury, and Mr. B. W. Ludington contributed to the technical preparation of this report through a subcontract with WESTEC Services, Inc.

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1. INTRODUCTION 1.1 PURPOSE OF REVIEW  !

Mis technical evaluation report (TER) documents an independent review of the outages of the emergency core cooling (ECC) systems at Baltimore Gas and Electric's (BG&E) Calvert Cliffs Nuclear Power Plant Units 1 and 2. The purpose of this evaluation is to determine if the Licensee has submitted a report that is complete and satisfies the requirements of 'IMI Action Item 4

II.K.3.17, " Report on Outac,es of Emergency Core-Cooling Systems Licensee Report and Proposed Technical Specification Changes."

1.2 GENERIC BACKGROUlm Pbilowing the Three Mile Island Unit 2 accident, the Bulletins and Orders Task Force reviewed nuclear steam supply system (NSSS) vendors' small break loss-of-coolant accident (LOCA) analyses to ensure that an adequate basis existed for developing guidelines for small break LOCA emergency procedures.

During these tsviews, a concern developed about the assumption of the worst single failure. Typically, the small break LOCA analysis for boiling water

reactors (BWRs) assumed a loss of the high pressure coolant injection (HPCI) system as the worst single failure. However, the technical specifications permitted plant operation for substantial periods with the HPCI system out of

service with no -limit on the accumulated outage time. There is concern not only about the HPCI system, but also about all ECC systems for which substantial outages might occur within the limits of the present technical specification. Therefore, to ensure that the small break LOCA analyses are consistent with the actual plant response, the Bulletin and Orders Task Force recommended in NUREG-0626 [1] , " Generic Evaluation of Feedwater Transients and Small Break Ioss-of-Coolant Accidents in GE-Designed Operating Plants and Near-Tern Operating License Applications," that licensees of General Electric (GE)-designed NSSSs do the following

" Submit a report detailing outage dates and lengths of the outages for all ECC systems. The report should also include the cause of'the outage (e.g., controller failure or spurious isolation) . The outage data for i

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4 i TER-C5506-268/269 ECC components should include all outages for the last five years of operation. The end result should be the quantification of historical unreliability due to test and maintenance outages. This will establish if a need u ists for cumulative outage requirements in technical specifications."

Later, the recommendation was incorporated into NUREG-0660 [2], "NRC Action Plan Developed as a . esult of the TMI-2 Accident," for GE-designed

• NSSSs plants as TMI Action Item II.K.3.17. In NUREG-0737 [3], " Clarification of TMI Action Plan Requirements," the NRC staf f expanded the Action Item to include all light water reactor plants and added a requirement that licensees propose changes that will improve and control availability of ECC systems and components. In addition, the contents of the reports to be submitted by the licensees were further clarified as follows:

"The report should contain (1) outage dates and duration of outages; (2) cause of the outage; (3) ECC systems or components involved in the outage; and (4) corrective action taken."

1.3 PLANT-SPECIFIC BACKGROUND On December 30, 1980 [4], BG&E submitted a report in response to NUREG-0737, Item II.K.3.17, " Report on Outages of Emergency Core-Cooling ,

Systems Licensee Report and Proposed Technical Specification Changes." The report submitted by BG&E covered the period from January 1,1975 to December 30, 1980 for Calvert Cliffs Unit 1 and from April 1,1975 to December 38, 1980 for Calvert Cliffs Unit 2. In response to a request for additional information (RAI), BG&E submitted two additional reports on April 13, 1982 [5]

and May 13, 1982 [6] providing further information on ECCS outages. These reports covered the period from January 1,1977 to February 28, 1981 for Calvert Cliffs Units 1 and 2.

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2. REVIEN CRITERIA The Licensee's response to NUREG-0737, Item II.K.3.17, was evaluated against criteria provided by the NRC in a letter dated July 21, 1981 (7]

outlining Tentative Work Assignment F. Provided as review criteria in Reference 5, the NBC stated that the Licensee's response should contain the following information:

1. A report detailing outage dates, causes of outages, and lengths of

. outages for all ECC systems for the last 5 years of operation. This report was to include the ECC systems or components involved and corrective actions taken. Test and maintenance outages were to be included.

2. A quantification of the historical unavailability of the ECC systems

.and vaats due to test and maintenance outages.

3. Proposed changes to improve the availability of ECC systems, if necessary. ,

, The type of information required to satisfy the review criteria was clarified by the NRC on August 12, 1981 [8]. Auxiliary systems such as -

component cooling water and plant service water systems were not to be considered in determining the unavailability of ECC systems. Only the outages of the diesel generators were to be included along with the primary ECC system outages. Finally, the "last five years of operation" was to be loosely interpreted as a continuous 5-year period of recent operation.

On July 26, 1982 [9], the NRC further clarified that the purpose of the review was to identify those licensees that have experienced higher ECC system outages than other licensees with similar NSSSs. The need for improved reliability of diesel generators is under review by the NBC. A Diesel Generator Interim Reliability Program has been proposed to effect improved performance at operating plants. As a consequence, a comparison of diesel generator outage information within this review is not required.

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3.- TECHNICAL EVALUATION l

3.1 REVIEN OF COMPLETENESS OF THE LICENSEE'S REPORT r

The ECC systems at BG&E's Calvert Cliffs Nuclear Power Plant Units 1 and 2 consist of the following four separate systems:

o safety injection (SI) tank o high pressure safety injection (HPSI) o low pressure safety injection (LPSI) o refueling water storage tank.

In References 4, 5, and 6, BG&E also included systems and components that support the BCC systems in carrying oct their design functions under various accident conditions. The support systems ares o component cooling service water system o containment cooling

o standby diesel generators o engineered safety feature actuation system (ESFAS) .

For each ECC system outage event, BG&E provided the outage dates, the duration, and the cause, plus sufficient description to discern the corrective action taken. Maintenance and aurveillance testing activities were included in the ECC system outage data. A complete review of outage data was provided by BG&E for the period from January 1,19.77 to February 28, 1981 for Calvert Cliffs Units 1 and 2.

l l Based on the preceding discussion, it has been established that BG&E has submitted a report which fulfills the requirements of review criterion 1 i without exception.

l 3.2 COMPARISON OF ECC SYSTDI OUTAGES WITH THOSE OF OTHER PLANTS The outages of ECC systems can be categorized as (1) unplanned outages due to equipment failure or (2) planned outages due to surveillance testing or ,

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preventive maintenance. Unplanned outages are reportable as Licensee Evant Reports (LERs) under the technical specifications. Planned outages for periodic maintenance and testing are not reportable as LERs. The technical specifications identify the type and quantity of ECC equipment required as well as the maximum allowable outage times. If an outage exceeds the maximum allowable time, then the plant operating mode is altered to a lower status consistent with the available ECC system components still operational. The f

purpose of the technical specification maximum allowable outage times is to prevent extended plant operation without sufficient ECC system protection.

The maximum allowable outage time, specified per event, tends to limit the unavailability of an ECC system. However, there is no cumulative outage time limitation to prevent repeated planned and unplanned outages from accumulating exteamive BCC system downtime.

Unavailability, as defined in general terms in WASH-1400 [10), is the .

probability of a system being in a failed sta'te when required. However, for

! this review, a detailed unavailability analysis was not required. Instead, a j preliminary estimate of the unavailability of an ECC system was made by cal-culating the ratio of the ECC system downtime to the number of days that the plant was in operation during the last 5 years. To simplify the tabulation of operating time, only the period when the plant was in operational Mode 1 was considered. This simplifying assumption is reasonable given that the period of time that a plant is starting up, shutting down, and cooling down is small compared to the time it is operating at power. In addition, an ECC system was considered down whenever an ECC system component was unavailable due to any cause.

It should be noted that the ratio calculated in this manner is not a true measure of the ECC system unavailability, since outage events are included that appear to compromise system performance when, in fact, partial or full function of the system would be expected. Full function of an ECC system would be expected if the design capability of the system exceeded the capacity required for the system to fulfill its safety function. For example, if an i ECC system consisting of two loops with multiple pumps in each loop is b Franklin Research Center 4oa aanw. rrw en==. .

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designed so that only one pump in each loop is required to satisfy core cooling requirements, then an outage of a single pump would not prevent the -

i system from performing its safety function. 'In addition, the actual ECC system unavailability is a function of planned and unplanned outages of essential support systems as well as ,of planned and unplanned outages of primary ECC system components. In accordance with the clarification discussed in Section 2, only the effects of outages associated with primary ECC system components and emergency diesel generators are considered in this review. The inclusion of.all outage events assumed to be true ECC system outages tends to overestimate the unavailability, while the exclusion of support system outages tends to underestimate the unavailability, of ECC systems and components.

, Only a detailed analysis of each ECC system for each plant could improve the conf M==e= in the calculated result. Such an analysis is beyond the intended j scope of this report.

The planned and unplanned (forced) outage' times for the four ECC systems (SI tank, HPSI, LPSI, and RNST) and the standby diesel generators were identified from the outage information in References 4, 5, and 6, and are shown in number of days and as a percentage of plant operating time per year in Tables 1 and 2 for Calvert Cliffs Units 1 and 2, respectively. Outhges ,

that occurred during nonoperational periods were eliminated as were those caused by failures or test and maintenance of support systems. Data on plant

, operating conditions were obtained from the annual rehorts, " Nuclear Power I

1 Plant Operating Experience" (11-14], and from monthly reports, " Licensed Operating Reactors Status Summary Reports" (15] . The remaining outages were segregated into planned and unplanned outages based on BG&E's description of the causes. The outage periods for each category were calculated by summing the individual outage durations.

i Observed outage times of various ECC systems'at Calvert Cliffs Uriits 1 and 2 were compared with those of other PWRs. Based on this comparison, it was concluded that the historical unavailability of the SI tank, HPSI, LPSI, and RNST systems has been consistent with the performance of those syste;ns throughout the industry. The observed unavailability was less than the i

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Table 1. Planned and Unplanned (Forced) Outage Times for Calvert Cliffs Unit 1*

h$3 tw2 SI Tank HPSI LPSI RWST Diesel Generator Days of Plant Outage in Days Outage in Days Outage in Days Cutage in Days Gdtage in Days g Year Operation Forced Planned Forced Planned Forced Planned Forced Planned Forced Planned 1977 263.2 0.0 0.0 0.0 0.13 0.0 1.19 0.0 0.10 3.15 14 ,34 (0 05%) (0.454) (0.044) (1.2%) (5.45%)

l 1978 256.3 0.0 0.0 0.0 0.13 g 0.02 1.19 0.0 0.10 0.76 12.54 4i (0.0 54) (0.014) (0.464) (0.044) (0.304) (4.894) 1979 256.4 0.0 0.0 1.04 0.56 1.27 1.19 0.0 0.10 5.06 13.54 i

(0.41%) (0.22%) (0.504) ( 0.464) (0.044) (1.974) (5.284) 1980 270.7 0.04 0.0 3.17 0.13 0.0 1.19 0.0 0.10 0.32 13.31 (0.01%) (0.06%) (0.05%) (0.444) (0.04%) (0.12t) (4.924)

Total 1046.6 0.04 0.0 1.21 0.95 1.29 4.76 0.0 0.40 9.29 53.73 I

(<0.01%) (0.12%) (0.09%) (0.124) (0.45%) (0.04%) (0.896) (5.13%)

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a 5' 1 Table 2. Planned and Unplanned (Forced) Outage Times for Calvert Cliffs Unit 2*

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@ SI Tank H PSI LPSI RWST Diesel Generator Dayt of Plant Outage in Days Outage in Days Outage in Days Outage in Days Outage in Days k" Forced Planned Forced Planned Forced Planned Forced Planned Year Operation Forced Planned 1977 240.5 (a) 0.0 0.0 0.11 0.90 0.0 1.19 0.0 0.10 0.0 16.99 (0.054) (0.376) (0.494) (0.04%) (7.06%)

297.3 A.13 1.19 0.02 0.10 0.87 12.43 iI 1978 0.3,9 0.0 0.0 0.0 (0.404) (0.014) (0.034) (0.294) (4.184)

(0.134) (0.044) 1979 283.2 0.61 0.08 0.0 0.13 0.0 1.19 0.0 0.10 0.03 17.45 (0.226) (0.034) (0.056) ( 0.424) (0.044) (0.014) (6.164) 1980 353.1 0.0 0.0 0.0 0.13 0.0 1.19 0.17 0.10 0.42 21.89 (0.044) (0.344) (0.054 (0.034) (0.124) (6.204) l Total 1174.1 1.00 0.08 0.11 1.29 0.0 4.76 0.19 0.40 1.32 68.76 (0.096) (0.01%) (0. 01%) (0.114) (0.41%) 0.01% (0.03%) 0.114 (5.864) i N

• Numbers in parentheses indicate system outage time as a percentage of total plant operating time. El

a. Commercial operation began April 1, 1977.

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TER-C5506-268/269 industrial mean for all ECC systems except the Unit 1 LPSI, which was less

- than about one standard deviation above the industrial mean, assuming that the underlying unavailability is distributed lognormally. The outage times were also consistent with existing technical specifications. The outages of the standby diesel generators were not included in this comparison.

3.3 REVIEN OF PROPOSED CHANGES TO IMPROVE THE AVAILABILITY OF ECC EQUIPMENT In References 4, 5, and 6, BG&E did not propose any changes to improve the availability of ECC systems and ccaponents.

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4. CONCLUSIONS Baltimore Gas and Electric Company (BG&E) has submitted a report for

. Calvert Cliffs Units 1 and 2 that contains (1) outage dates and durations, (2) causes of the outages, (3) ECC systems or components involved in the outages, and (4) corrective actions taken. It is concluded that BG&E has fulfilled the requirements of NUREG-0737, Item II.K.3.17. In addition, the historical unavailability of the SI tanks, HPSI, LPSI, and RNST systems has been consistent with the performance of those systems throughout the industry. The observed unavailability was less than the industrial mean for all ECC systems except the Unit 1 LPSI which was less than about. one standard deviation above the industrial mean. 'Ihe outage times were also consistent with existing technical specifications. i

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5. REFERENCES

1. NURB3-0626

. " Generic Evaluation of Feedwater Transients and Small Break Ioss-of-Coolant Accidents in GE-Designed Operating Plants and Near-Term Operating License Applications" NRC, January 1980

2. NUREG-0660 "NRC Action Plan Developed as a Result of the TMI-2 Accident" NRC, March 1980

3. NUREG-0737

" Clarification of TMI Action Plan Requirements" NRC, October 1980

4. A. E. Lundvall, Jr. (BG&E)

Letter to D. G. Eisenhut (NRR)

Subject:

Response to NUREG-0737 December 30 1980

5. A. E. Lundvall, Jr. (BG&E)

Letter to R. A. Clark (Operating Reactors Branch 93, NRC) O

Subject:

TMI Action Plan Items II.K.3.2 and II.K.3.17 April 13, 1982

6. A. E. Lundvall, Jr. (BG&E)

. Idttter to R. A. Clark (Operating Reactors Branch 93, NRC)

Subject:

TMI Action Plan Items II.K.3.17 May 13, 1982

7. J. N. Donohew, Jr. (NBC)

Letter to Dr. S. P. Carfagno (FRC) .

Subject:

Contract No. .

NBC-0 3-81-13 0, Tentative Assignment F July 21, 1981

8. NRC Meeting between NRC and' FBC.

Subject:

C5506 Tentative Work Assignment F, Operating Reactor PORV and ECCS Outage Reports August 12, 1981

9. NRC Meeting between NRC and FBC.

Subject:

Resolution of Review Criteria and Scope of Werk July 26,1982

10. WASH-1400

" Reactor Safety Study" NRC, October 1975 .

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11. NUREG-0366

" Nuclear Power Plant Operating Experience 1976" NRC, December 1977

12. NUREG-0483

. "Itaclear Power Plant Operating Experience 1977" NRC, February 1979

13. NUREG-0618

• ttaclear Power Plant Operating Experience 1978" NRC, December 1979

14. NUREG/CR-1496 "tAtclear Power Plant Operating Experience 1979" NRC, May 1981

15. NUREG-0020

" Licensed Operating Reactors Status Summary Report"

• 1n== 4, Mos. 1 through 12, and volume 5, No. 1 NRC, December 1980 through January 1981 1

500 Franklin Research Center a N.an as N Fr.n. a %.

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