ML19323H327
| ML19323H327 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 06/10/1980 |
| From: | Sylvia B VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| 463, NUDOCS 8006120386 | |
| Download: ML19323H327 (5) | |
Text
- w VinoxxrA ELucrnrc ANu Powzu Cox eAxy u ncumoso,vs uorn sa uunas June 10, 1980 Mr. James P. O'Reilly, Director Serial No. 463 Office of Inspection and Enforcement N0/RMT:ms U. S. Nuclear Regulatory Commission Docket Nos. 50-338 Region II 50-339 101 Marietta Street, Suite 3100 License Nos. NPF-4 Atlanta, Georgia 30303 NPF-7
Dear Mr. O'Reilly:
We have reviewed your letter of May 16, 1980, in reference to the inspection conduc'ted at North Anna Powe r Station on April 21 through 25, 1980, and reported in IE Inspection Report Nos. 50-338/80--20 and 50-339/80-21.
Our response to the specific infraction is attached.
We have determined that no proprietary information -is contained in the report.
Accordingly, the Virginia Electric and Power Company has no objection to these inspection reports being made a matter of public disclosure, k
Very truly yours,
,1
^
B. Ps. Sylvia Manager-Nuclear Operations and Maintenance Attachment ec: Mr. Robert A. Clark, Chief Operating Reactors Branch No. 3
Attachment Page 1 RESPONSE TO NOTICE OF VIOLATION ITEM REPORTED IN IE INSPECTION REPORT NO.
50-338/80-20 AND NO. 50-339/80-21 NRC COMMENT As required by 10 CFR 50 Appendix B Criteria XI as implemented by the Topical Quality Assurance Report VEP-3-A Section 17.2.11 written test procedures shall incorporate the requirements contained in applicable design documents.
The Nuclear Power Station Quality Assurance Manual, section 11, paragraph 2.1 farther requires that tests during the preoperatonal period shall derconstrate performance in accordance with design intent as described in the FSAR. FSAR section 6.3.1.3.5 (i) and FSAR comment 7.4 both identify the design feature which requires two separate operator actions to reset any engineered safeguards features (ESF) actuation causing equipment to revert to its normal mode of operation.
Contrary to the above, the North Anna Unit 1 preoperational test program had no provision to test the ESF reset design to assure its operation as described in FSAR section 7.3.1.3.5 (i) and FSAR comment 7.4.
This is an infraction.
RESPONSE
The above infraction is correct as stated.
In accordance with your inspection report the following addresses corrective steps taken or planned to insure that all equipment will respond to Engineering Safeguards Feature actuation resets according to the design criteria identified in the FSAR.
On November 6, 1979, during a review of system operation subsequent to a unit trip and safety injection actuation, it was discovered that cer-tain safety-related equipment returned to their non-safety mode upon reset of an ESF actuation signal.
This condition was reported to the NRC for Unit 1 pursuant to Technical Specification 6.9.1.8.1 and for-Unit 2 pursuant to 10 CFR 50.55 (e). At that time a review of drawings for all systems serving safety-related functions was immediately initiated to determine if any other deficiencies existed.
This review was performed by both Stone and Webster Engineering Corpora-tion and Vepco.
All reviews have been completed and all discrepancies have been identified and reported to the NRC.
The following deficiencies. in Engineered Safety Feature reset controls were ' discovered and reported to the NRC during the review of drawings by Stone and Webster and Vepco.
Att:chment Page 2 1.
Resetting of the Containment Depressurization Actuation Signal prior to expiration of the time delay relays will prohibit the start of the following pumps:
Recirculation Spray Pumps (195 and 210 sec.)
a.
b.
Service Water Monitor Sample Pumps (120 sec.)
Resolution.
The pump circuits for Unit 2 and for item (a) on Unit i have been modified so that once the CDA or SI is received, the pumps will continue through the timing sequence until, (1) reset CDA, and (2) place the control switch to the secured position. This modification will be complete for item (b) on Unit 1 during the next refueling outage.
2.
On resetting of Containment Depressurization Actuation (CDA),
Safety Injection (SI), or Main Steam Line Isolation (MSLI) signal, the following devices return to their non-emergency mode:
a.
Main Control Room Supply and Exhaust Air Operated Dampers 1
. b.
Charcoal Filter Operated Dampers c.
Containment hed rculation Fans d.
Control Rod Drive Cooling Fans q
e.
Service Water Valves to Containment Recirculat. ion Air Coolers f.
Divert Valves for the Air Ejector Exhaust g.
Main Steam Trip Valves Resolution:
The circuits for items a.
through c. have been modified for both units such that two operator actions are required to reposition or restart these devices; (1) reset CDA, SI or MSLI, and (2) operate associated control switch.
This modification for item d. has been completed on Unit 2.
During the'next refueling outage for Unit 1 items d.,
- f. and g.
will be modified as described above.
Item f.
for Unit 2 will be modified by January 1, 1981. During the first refuel-ing outage for Unit 2, item g. will be modified as described above.
Item c.
will not be changed for either Unit.
This item involves service water valves to containment recirculation air coolers; the valve circuit will not be modified since the service water mode of cooling has never been used (normal cooling is chilled water as described in Section 9.2.1 of the FSAR) and because - service water cooling is under administra-tive control.
h -
. e>
Attachment Page 3 By not modifying these valve circuits, there will be no reduc-tion in safety. Although these valves do return to their non-safety mode following reset of CDA, the containment isolation valves, which are in series with the SW valves, will remain closed thereby preventing the service water post accident flow path from being affected by the resetting of the CDA signal.
The flow diagram for this system is shown on Figure NIF FIG.
9.2.2-4 of the FSAR.
3.
The auxiliary feedwater pump turbine steam supply valves open upon receipt of the SI signal. The SI open signal is. removed when SI is reset, however, the valves remain open because the tripping of the main feedwater pumps on an SI signal would
" seal in" the trip valves.
This causes the valves to remain open when the SI signal is reset. This condition has not been reported to the NRC since the valves remain in their safety mode following ESF reset.
However, to be consistent with the station design, the Unit 2 circuit has been modified such that the valves will remain open following reset of SI regardless of the main feedwater pump breaker position. The Unit I cir-cuit will be modified during the next refueling outage.
Periodic tests for both units have been modified to demon-strate all equipment remains in its emergency mode upon reset-ting of the actuation signals.
The following tests were modified:
1-PT-57.4 Safety Injection Functional Test (Unit 1) 2-PT-57.4 Safety Injection Functional Test (Unit 2) 1-PT-66.3 Containment Depressurization Actuation Functional Test (Unit 1) 2-PT-66.3 Containment Depressurization Actuation Functional Test (Unit 2)
These tests are required at least once every 18 months pursuant to the applicable Technical Specifications.
Each test will be performed during the next unit refueling outage.
The refueling outages for Units ; and 2 are scheduled for December, 1980 and September, 1981 respectively.
The following special test will be developed to test main steam line isolation.
1-ST-25 Main Steam Line Isolation Reset Test (Unit 1) 2-ST-23 Main Steam Line Isolation Reset Test (Unit 2)
These tests will also be performed during the refueling shut-down of the applicable unit.
Attachment Page 4 Until corrective action is completed as described above, adequate administrative control is provided to the operator to maintain the design conditions.
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