ML20247E193
| ML20247E193 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 07/19/1989 |
| From: | Morris K OMAHA PUBLIC POWER DISTRICT |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-89-04, GL-89-4, LIC-89-663, NUDOCS 8907260111 | |
| Download: ML20247E193 (4) | |
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w Omaha Public Power District 1623 Harney Omaha Nebraska 68102 2247
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402/536-4000 l
July 19,1989 LIC-89-663 i
U.S. 99 clear Regulatory Commission 1
Attp:
Document Control Desk Mail Station P1-137 washington, DC 20555
References:
1.
Docket No. 50-285 2.
Fort Calhoun Station Technical Specification Amendment 52 dated October 14, 1980 3.
Letter from OPPD (R. L. Andrews) to NRC (Document Control Desk) dated December 15, 1987 (LIC-87-806) 4.
Letter from NRC (S. A. Varga) to OPPD dated April 3, 1989 5.
Letter from 0 PPD (K. J. Morris) to NRC (Document Control Desk) dated March 24, 1989 (LIC-89-202)
Gentlemen:
SUBJECT:
Notification of IST Program Changes:
Valves IV-HCV-712A-C, IV-HCV-385-C and IV-HCV-386-C The purpose of this letter is to notify the NRC f two changes to Fort Calhoun's ISI/IST Program that are not addressed in the ISI/IST Program Upgrade Plan that was submitted in Reference 3.
It is OPPD's position that these changes comply with ASME Section XI Subsection IWV 1980 Edition Winter 1980 Addenda.
In accordance with discussions between OPPD and the NRC and the general guidance in Generic Letter 89-04 (Reference 4), the licer e is to notify the NRC of prograc changes that are a deviation from the approved ISI/IST Program, but are still code ccmpliant.
In cases where a change complies with the code, approval is not required from the NRC prior to implementation.
Following are descriptions / justifications of these changes:
(1) IV-HCV-712A-C --
Instrument Air Accumulator Check Valve for the Spent Fuel Pool Charcoal Filter Bypass Valve.
Check valve IV-HCV-712A-C is located in a radiation area and continued 1
testing of this valve presents an ALARA concern for involved personnel.
I Inservice Testing (IST) was initially determined to be required for j
IV-HCV-712A-C per Operational Safety Analysis Report (0SAR) 87-10.
During 1
movement of irradiated fuel in the spent fuel storage areas, the function of process valve HCV-712A is to isolate the normal exhaust air flow path to ensure that the exhaust air flow is diverted through charcoal filters I
should a postulated fuel handling accident occur and cause an accidental i
release of radioactivity.
Instrument air accumulator check valve IV-HCV-712A-C functions to ensure that the air line leading to process l
valve HCV-712A remains pressurized following a loss of instrument air 890YS$.o11YehoyNn Deration of the process valve.
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I U.S. Nuclear Regulatory Commission l
LIC-89-663 Page 2 By Reference 2, the NRC issued an SER which concluded that "...
consequences of postulated accidents without charcoal filtration of the l
radioactivity released from the spent fuel pool and to the Safety Injection pump room are well within the exposure guidelines of 10CFR100...." Below i
is a chart showing a comparison of the potential consequences of a postulated fuel handling accident in the spent fuel pit, with and without charcoal filtration.
POTENTIAL CONSE0VENCES IN REM Exclusion Area low Population Boundary (910 m)
Zone (4800 m)
Thyroid Whole Body Thyroid Whole Body w/ charcoal filtration 15
.4 2
.4 w/o charcoal filtration 100
.4 13
.4 10CFR100 Limits:
300 Rem Thyroid 25 Rem Whole Body In addition, administrative controls ensure that the exhaust air is lined up to pass through the charcoal filters during movement of irradiated fuel assemblies.
Based on the above chart, administrative controls, and the fact that valve HCV-712A is a " fail-closed" valve, OPPD has determined that IV-HCV-712A-C is not required to perform a specific function in shutting down the reactor or in mitigating the consequences of an accident (no safety-related function), and it is therefore not required to be included in the IST Program.
This change to the IST Program is in compliance with the ASME Boiler and Pressure Vessel Code Section XI Subsection IWV, 1980 Edition Winter 1980 Addenda. The IST Program Plan will reflect this change with Revision 5 to the program, which will be submitted to the NRC within 2 months after completion of the 1990 refueling outage.
(2) IV-HCV-385-C and IV-HCV-386-C -- Instrument Air Accumulator Check Valves
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for the Cafety Injection Refueling Water Tank (SIRWT) Recirculation Isolatic h - ees Tbc process valves, HCV-385 and HCV-386 open to provide a recirculation pach from the Safety Injection and Containment Spray pumps back to the Safety Injection and Refueling Water Tank during the injection phase. This prevents dead heading the Safety Injection pumps. Check valves IV-HCV-385-C and IV-HCV-386-C function to ensure that the air line leading l
U.S. Nuclear Regulatory Commission LIC-89-663 Page 3 to process valves HCV-385 and HCV-386 remain pressurized following a loss of instrument air event, thus allowing operation of the process valves.
The accumulator that provides air to the process valves must remain pressurized to allow for closing of the valves when a Recirculation Actuation Signal (RAS) is initiated.
This prevents the return of contaminated water to the Safety Injection and Refueling Water Tank. The accumulator check valves IV-HCV-385-C and IV-HCV-386-C are leak tested to ensure that in case of loss of instrument air that the accumulator is able to close and hold the valves closed.
The instrument air check valves were tested quarterly for the first time in March of 1989. Subsequently, it has been determined that the potential exists for damage to the SI pumps during the performance of this surveillance test (ST). The ST requires that the mini-flow valve be closed in order to perform the test, thus preventing recirculation flow. During the period of time that the isolation valves (HCV-365 and HCV-386) are closed (~ 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> per valve), the possibility of an Safety Injection Actuation Signal or inadvertent start of one or more of the SI pumps is a concern. Although a low probability event, unless operator intervention occurred,.the pump or pumps could be run at shutoff head for an extended period of time which could cause the SI pumps to be damaged making them unavailable for an accident condition.
Based upon the above scenario, OPPD has determined that performing this test quarterly as required by the existing IST Program Plan, as submitted in Reference 3, could result in damage to the pumps and, therefore, it is not prudent to test quarterly.
Based on the concerns as stated above and in accordance with the ASME Code, OPPD has determined that valves IV-HCV-385-C and IV-HCV-386-C will not be tested quarterly as presently stated in the existing IST Program, Revision 4.
OPPD will test the Instrument Air Accumulator check valves IV-HCV-385-C and IV-HCV-386-C during Cold Shutdowns. This change to the IST Program is in compliance with the ASME Boiler and Pressure Vessel Code Section XI, Subsection IWV 1980 Edition Winter 1980 Addenda. The IST Program Plan will reflect this change with Revision 5 to the program.
OPPD has determined that the above stated changes to the IST Program are in compliance with the ASME Boiler and Pressure Vessel Code Section XI, Subsection
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IWV 1980 Edition Winter 1980 Addenda and the NRC guidance stated in Generic j
Letter 89-04 (Reference 4).
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. r-U. S. Nuclear Regulatory Commission
. LIC-89-663
. Page 4 If you' have any questions, please contact me.
Sincerely, o ris Division Manager Nuclear Operations c: -Leboeuf, Lamb, Leiby and MacRae R.. D. Martin, NRC Regional Administrator
- A..Bournia, NRC Project Manager P. H. Harrell,'NRC Senior-Resident Inspector k
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