ML20045B672
| ML20045B672 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 06/14/1993 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20045B671 | List: |
| References | |
| NUDOCS 9306180253 | |
| Download: ML20045B672 (4) | |
Text
[e neo m
o UNITED STATES NUCLEAR REGULATORY COMMISSION e
n WASHINGTON, D. C. 20555
~.....f SAFETY EVALVATICN BY THE OFFICE OF NUCLEAR REACTOR REGULATION REL ATED TO AMENDMENT NO. 21 TO FACILITY OPERATING LICENSE NO. NPF-86 NORTH ATLANTIC ENERGY SERVICE CORPORATION SEABROOK STATION, UNIT N0. 1 DOCKET NO. 50-443
1.0 INTRODUCTION
During a routine review of a Station Procedure for performing a full-stroke exercise of the Residual Heat Removal (RHR) pump discharge check valves and associated cold-leg injection check valves, an inconsistency was identified between the procedure's acceptance flow value and that of Technical Specification Surveillance Requirement value.
A review of the Westinghouse Emergency Core Cooling System analysis confirmed that the TS value was incorrect and non-conservative.
The details of the discovery and subsequent actions are identified in a Licensee Event Report (LER) (Ref.1).
Corrective actions identified in the LER included the development of a proposed license amendment.
By application dated October 22, 1992, (Ref. 2), North Atlantic Energy Service Corporation (NAESC0/the licensee) proposed an amendment to the Appendix A Technical Specifications (TSs) for the Seabrook Station, Unit 1 (Seabrook).
The proposed change would increase the acceptance value for the sum of the flows in the RHR System injection lines when one RHR pump is operating.
2.0 EVALUATION Surveillance Requirement (SR) 4.5.2 h.3) currently specifies 2828 gpm for the acceptance flow value.
NAESCO has determined that this is the correct value for the ficw into the reactor coolant system (RCS) via three injection lines rather than the total of the three lines plus flow through the fourth line.
However, the value that should be specified in SR 4.5.2 h.3) is the sum of the flows in four RHR lines, i.e., 3869 gpm.
During certain design basis calculations, three of the four injection lines are assumed to deliver coolant to the reactor vessel; the fourth line is assumed to spill to containment through a rupture in the RCS.
Table 1 is a comparison of calculated and RHR test flow information provided by the NAESCO (Ref. I and 2).
The acceptance value (2828 gpm) specified in SR 4.5.2 h.3) does not meet the Westinghouse calculated requirement (3868 gpm).
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As can be seen from Table 1, all testing demonstrated total flows clearly exceeding the Westinghouse calculated requirement except the November 1989 test.
NAESCO has stated that this test was conducted with the pressurizer vented to atmosphere.
RHR flow was throttled during the November 1989 test to t
prevent overfilling of the RCS, therefore, the test result demonstrated that the 2828 gpm acceptance value could be met but did not demonstrate the full capability of the system.
NAESCO has proposed a change to require 3869 gpm to assure that the design basis requirement is met.
NAESCO also stated that it has reviewed the TS bases and has determined that no change to the bases is required.
Table 1.
Comparison of RHR Flow Rate Information ltem RHR flow rate, gpm Design basis flow to core via three RHR 2712 injection lines - no allowance for pump degradation Required total flow through four RHR 3828 l
injection lines to obtain design basis core flow - no pump degradation Required total flow to meet design basis via 2828 three RHR injection lines - 5% allowance for pump degradation Required total flow through four RHR 3868 injection lines to meet design basis core flow - 5% allowance for pump degradation Seabrook In-Service Testing procedure 4350 acceptance value RHR system initial testing (date not stated)
>3868 9/89 RHR "A" train test (throttled),
4012 pressurizer vented (Ref. 1) 11/89 RHR "B" train test (throttled),
3776 pressurizer vented 9/10/91 RHR "A" train test, reactor vessel 5013 head removed 9/10/91 RHR "B" train test, reactor vessel 4696 head removed
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L The staff has audited the NAESCO's request (Ref. 2), including the proposed TS changes and NAESCO's safety evaluation of the change.
The staff also has considered appropriate portions of the Final Safety Analysis Report (Ref. 3) e and the Standard Review Plan (Ref. 4).
The staff concurs with NAESCO's conclusion that the currently specified value is incorrect, and the proposed change would correct this error.
3.0 STATE CONSULTATION
In accordance with the Commission's regulations, the New Hampshire and Massachusetts State officials were notified of the proposed issuance of the amendment.
The State officials had no comments.
4.0 ENVIRONMENTAL CONSIDERATION
The amendment changes a surveillance requirement.
The NRC staff has r
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 Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration, and there has been no public comment on such finding (57 FR 61119).
Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to 10 CFR SI.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
5.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (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.
Principal Contributors:
W. Lyon A. De Agazio Date:
June 14, 1993 s
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6.0 REFERENCES
l (1)
Licensee Event Report 92-001 Revision 01, "Non-Conservative Technical Specification Value, April 8,1993.
(2)
Feigenbaum, Ted. C., " License Amendment Request 92-12: Change in Residual Heat Removal System Injection Line Flow Rate Acceptance Value,"
Letter to USNRC from Senior Vice President and Chief Nuclear Officer, North Atlantic Energy Service Corporation, NYN-92145, October 22 1992.
(3)
"Seabrook Station Final Safety Analysis Report," Public Service Company of New Hampshire, New Hampshire Yankee Division.
t (4)
" Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants, LWR Edition, NUREG-0800, July, 1987.
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