ML20248B300

Safety Evaluation Supporting Amend 116 to License DPR-61

ML20248B300
Person / Time
Site:	Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png
Issue date:	05/31/1989
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20248B290	List: ML20248B287 ML20248B294 ML20248B300
References
TASK-03-05.A, TASK-05-05, TASK-3-5.A, TASK-5-5, TASK-RR GL-84-04, GL-84-4, NUDOCS 8906090004
Download: ML20248B300 (4)

Text

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oce 1 o UNITED STATES g

g ) g NUCLEAR REGULATORY COMMISSION

.  ;; WASHINGTON, D. C. 20555 g%.../ v SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.116 TO FACILITY OPERATING LICENSE NO. DPR-61 CONNECTICUT YANKEE ATOMIC POWER COMPANY HADDAM NECK PLANT DOCKET NO. 50-213

1.0 INTRODUCTION

By letter dated April 25, 1986 Connecticut Yankee Atomic Power Company (CYAPC0/ licensee) submitted to the NRC staff a proposed amendment to add a new Technical Specification section on Peactor Coolant System Leakage Detection Systems. In a letter dated August 9, 1988, the NRC staff requested additional information to support our review. In addition the NRC staff requested that the amendment be revised to be consiste'nt with the Westinghouse Standard-format Technical Specifications (STS). By letter dated May 30, 1989, CYAPC0 responded to our recuest for additional information and revised the proposed Technical Specifications (TS) to,be more consistent with the STS format.

2.0 DISCUSSION 10 CFR 50 (GDC 30), as implemented by Regulatory Guide (RG) 1.45 and Standard Review Plan (SRP, NUREG-0800) Section 5.2.5, describes the types and sensitivity of systems, and their seismic, indication, and testability criteria, necessary to detect leakage of primary reactor coolant to the containment or to other interconnected systems.

RG 1.45 recomends that at least three separate leak detection systems be installed in a nuclear power plant to detect unidentified leakage from the reactor coolant pressure boundary (RCPB) to the primary containment and that their sensitivity be at least I gpm within I hour. Leakage from identified sources must be isolated so that the flow of this leakage may be monitored separately from unidentified leakage. The detection systems should be capable of performing their functions after certain seismic events and of being checked in the control room. Of the three se l recomended, two of the methods should be (1)parate sump levelleak anddetection methods flow monitoring and (2) airborne particulate radioactivity monitoring. The third method may be either monitoring the condensate flow rate from air coolers or monitoring airborne gaseous radioactivity. Other detection methods--such as monitoring humidity, temperature, or pressure--should be considered to be indirect indications of leakage to the containment.

G906090004 PDR 890531 P ADOCK 05000213 PDC L - __- _

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, For. postulated break locations, where separation and/or restraint is not practical or possible to mitigate' the effects of an .high energy pipe break (HEPB) in an operating plant. augmented inservice inspection in conjunction with leakage detection may be used to identify degradation in piping before it propagates.into a break. Most crack growth processes (e.g., fatigue and

stress corrosion) are time dependent, yet experience has shown that it is almost impossible to quantify the times (e.g., hours to months have been

- experienced). However, time to achieve the required sensitivity is important

, because the exposure times for transient loadings are increased and, thus, the potential for failure is increased.

. This TS ensures a reliable means of detecting unidentified leakage from the ,

reactor coolant. system which potentially could be due to a circumferential through wall flaw in primary system piping. The required instrument sensitivity is one gallon per minute (gpm) in 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> as stated.in. condition i: (2) of Generic Letter 84-04, " Safety Evaluation of Westinghouse Topical Reports

! Dealing with Breaks in PWR Primary Main Loops."

3.0 EVALUATION The Systematic Evaluation Program (SEP) report (NUREG-0826) concluded that if the following criteria were met, the intent of RG 1.45 would be satisfied:

1. In order to preclude-pipe breaks by detecting cracks as they develop, at -least one reliable method of . leakage detection should be provided whose leakage sensitivity is commensurate with the leakage rate from the limiting crack size, as es,tablished in SEP Topic III-5.A.

This criteria was eventually established in Generic Letter 84-04.

2) The leakage detection method identified in (1) should be qualified

, to a safe-shutdown-earthquake (SSE) seismic event or the licensee should provide procedures that specify actions to be taken for a seismic event to accommodate any resulting failures of the leakage detection equipment (e.g., plant shutdown).

3) Provide limiting conditions for operation and surveillance requirements regarding the leakage detection systems, as recommended by RG 1.45 and the Westinghouse Standard Technical Specifications (NUREG-0452, Rev. 4)

4) A reactor coolant inventory balance is not a current licensing

- requirement; however, it is considered an acceptable alternative te leak detection systems.

CYAPC0 has provided three leakage detection systems in the proposed TS. These systems are 1) the Volume Control Tank (VCT) Level Monitoring, 2) Containment here Gaseous Radioactivity Monitoring System and 3) the Containment Main Atmosp(CMS)

Sump Level Monitoring System. In addition by letter dated May ,

1989. CYAPC0 has stated that all three systems can detect a 1 ppm leak in 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> as required in Generic Letter 84-04. CYAPC0 states the most reliable and l

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. sensitive of the three systems is the VCT level monitor, which can identify at steady state a 1 gpm leak in 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. Even though the VCT level monitor is a reactor coolant system inventory balance, SEP concluded that it was an acceptable alternative to leak detection systems and is acceptable.

CYAPC0 states that none of the leakage detection systems are qualified to a safe-shutdown-earthquake (SSE) event. In lieu of qualifying the equipment, CYAPC0 has provided TS to require an operability check of the VCT and the CMS level monitoring systems following any seismic event greater than the operating basis earthquake (3 the SSE). If either system is inoperable, the TS would require a plant shutdown as delineated in the " Action" statements. As noted earlier, this was an acceptable alternative provided in the SEP report.

Therefore, while the three systems do not explicitly meet the RG 1.45 recommendations, the leakage detection systems do meet the criteria set forth in SEP Topic V-5 for meeting the intent of RG 1.45 and is acceptable.

The purpose of the proposed TS is to provide limiting conditions of operation and surveillance requirements for the above leakage detection systems. The major deviation between the Westinghouse STS and the proposed TS are in the

" Action" statements regarding the Containment Atmospheric Gaseous Radioactivity ,

(CAGR) Monitoring System and the CMS level monitoring system.

The STS allows continued operation for 30 days when the CAGR monitoring system is declared inoperable, if the plant can provide grab samples at least once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. CYAPCO's proposed TS allows continued operation for 7 days, when the CAGR monitoring system is declared inoperable, if grab samples are taken every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. However, at the end of 7 days if the CAGR monitoring system is still inoperable, the licensee will prepare and submit a special report to the Commission outlining actions taken, cause of inoperability and plans for restoring the monitor. The staff has reviewed this deviation and concludes

. that it meets the intent of the STS as the staff would not expect that any needed corrective actions would be performed significantly beyond the 30 days allowed by the STS.

If the CMS level monitoring system is inoperable, the STS would require the '

plant to be in Hot Standby within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and cold shutdown within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. CYAPCO has proposed to provide a 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> period to repair the CMS level monitoring system before shutting down the plant. In addition, CYAPC0 has provided an additional " Action" statement which would provide for increased grab sampling during the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> period if the CAGR

, monitoring system is inoperable at the same time. CYAPC0 has stated the CMS I

level monitoring system is not a primary means of leak indication and in most cases would be used only to confirm leakage detected by one of the other methods. SEP Topic V-5 only recomended that at least one reliable method for leakage detection be provided. CYAPC0 has stated that the system selected to meet the SEP criteria is the VCT level monitoring system with the CAGR monitoring system and the CMS level monitoring system as back-up systems.

Therefore, while CYAPC0 has not followed the STS, their " Action" statements are relaxed but consistent with the recommendations made in SEP Topic V-5, and acceptable.

The NRC staff has reviewed the proposed TS and agrees that while it deviates from the explicit recommendations of the STS and RG 1.45, it is consistent with the criteria set forth for the leakage detection systems in SEP Topic V-5 and is acceptable

4.0 ENVIRONMENTAL CONSIDERATION

This amendment changes a requirement with respect to the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes surveillance requirements. We have determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The staff has previously published a proposed finding that the amendment involves no significant hazards consideration and there has been no public comment on such finding. Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 551.22(c)(9). Pursuant to 10 CFR 551.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.

5.0 CONCLUSION

We have concluded, based on the considerations discussed above, that (1) there is reasonable assurance that the health and safety of the public will not be e'ndangered by operation in the proposed manner, and (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

• Dated: May 31, 1989 Principal Contributor:

A. Wang l

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