ML18094B291
| ML18094B291 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 01/31/1990 |
| From: | Labruna S Public Service Enterprise Group |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NLR-N90025, NUDOCS 9002140264 | |
| Download: ML18094B291 (5) | |
Text
Public Service Electric and Gas Company Stanley LaBruna Public Service Electric and Gas Company P.O. Box 236, Hancocks Bridge, NJ 08038 609-339-4800 Vice President - Nuclear Operations JAN 3 1 1990 NLR-N90025 U.S. Nuclear Regulatory Commission Document Control Desk Washington DC 20555 Gentlemen; SUPPLEMENTAL RESPONSE; NOTICE OF DEVIATION 272/89-13-04 SALEM GENERATING STATION UNIT NO. 1 DOCKET NO. 50-272 Public Service Electric and Gas hereby transmits, as Attachment 1 to this letter, a description of the planned modifications/actions to achieve compliance with Regulatory Guide 1.97.
This information supplements our previous submittals transmitted September 5, 1989 and December 28, 1989.
If there are any questions regarding the attached information, please feel free to contact us.
Sincerely, Attachment
Document Control Desk NLR-N90025 c
Mr. J. c. Stone Licensing Project Manager Mr. T. Johnson Senior Resident Inspector 2
Mr. w. T. Russell, Administrator Region I Mr. Kent Tosch, Chief New Jersey Department of Environmental Protection Division of Environmental Quality Bureau of Nuclear Engineering CN 415 Trenton, NJ 08625 JAN 3 1 l990
ATTACHMENT TO NLR-N90025
SUMMARY
OF MODIFICATIONS REQUIRED TO PROVIDE TYPE A, CATEGORY 1 INSTRUMENTATION FOR THE INDICATION OF A STEAM GENERATOR TUBE RUPTURE PSE&G has evaluated potential modifications to the Channel R46A-E High Range Main Steam Line Radiation Monitors required to assure that Regulatory Guide (RG) 1.97 Type A, Category 1 instrumentation is available for the detection and identification
- of a steam generator tube rupture (SGTR) at Salem Generating Station Unit Nos. 1 & 2 (SGS 1 & 2).
The subject evaluation is documented by PSE&G Engineering Evaluation (EE) S-C-VAR-CEE-0388, "Engineering Evaluation of Steam Generator Tube Rupture Indication Requirements at SGS 1 & 2 11
- The following is a summary description of the modifications to be* accomplished to assure compliance with RG 1.97 requirements.
PSE&G has concluded that the Channel R46A-E High Range Main Steam Line Monitors meet the RG 1.97 requirements for Type A, Category 1, with the exception that the monitors do not meet the Category 1 requirements for redundancy.
The Channel R46E High Range Main Steam Line Monitor does not by design provide redundancy for the Channel R46A-D High Range Main Steam Line Monitors.
Rather, the R46E detector and associated instrumentation serves as a backup to the R46A-D monitors and provides primary indication of main steam line radiation in the event of failure of any one R46A-D detector and/or associated instrumentation.
The R46E monitor may be used to detect a SGTR and to determine the specific faulted steam generator based upon a comparison of the R46E alarm state/indication to the alarm state/indication of the remaining three (3) operable monitors.
PSE&G has further concluded that, upon implementation of the modifications specified below, sufficient instrumentation is installed to the SGS 1 & 2 units for the indication of a SGTR.
This conclusion is based upon; a) the instrumentation previously used at eight (8) other operating nuclear units to detect actual SGTRs, b) the technical guidance provided by the Westinghouse Owners Group (WOG) relative to the indication of a SGTR, and c) the functionally redundant instrumentation available at SGS 1 & 2 for the indication of a SGTR.
The following instruments are identified as a functionally redundant set for the purpose of SGTR detection:
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- R46A-E High Range Main Steam Line Radiation Monitors
- steam Generator Narrow Range Level Instruments
- steam Generator Wide Range Level Instruments
- R15 Condenser Air Ejector Exhaust Radiation Monitor These instruments bear a known relationship in their response to a SGTR as evidenced by actual SGTR events at other nuclear units.
Functional redundancy for the indication of a parameter by diverse instrumentation has been previously discussed, relative to AFW flow, and found acceptable by the NRC in Safety Evaluation Report, Supplement No. 4, II.E, Auxiliary Feedwater Indication (2.1.7.b-NUREG-0578), April 1980. See also Safety Evaluation, Salem Unit No.
1, Auxiliary Feedwater Automatic Initiation and Flow Indication, Action Plan Item II.E.1.2, June 16, 1981 and Safety Evaluation, Salem Unit No. 2, Automatic Initiation and Flow and Steam Generator Level Indication for the Auxiliary (Emergency) Feedwater System, June 22, 1981.
The R15 Condenser Air Ejector Exhaust Radiation Monitor is not qualified for Type A Category 1 service in accordance with RG 1.97 due to the monitor's location in the seismic class 3 Turbine Building.
However, due to the high reliability demonstrated by equivalent instruments during actual SGTR events, it is reasonable to credit the R15 monitor as a functionally redundant indication of a SGTR.
As a measure of prudency, this indication must be evaluated in conjunction with other instrumentation of the functionally redundant set to assure that actions are not taken without consideration for qualified instruments.
All other instruments of the functionally redundant set are, or will be, qualified for Category 1 service in accordance with RG 1.97.
To provide for the qualification and reliability of the functionally redundant set of instrumentation credited for the indication of a SGTR, the following modifications will be implemented:
- 1) A Design Change Package (DCP) will be developed in accordance with PSE&G approved procedures to change the power provided to R46A-D and associated instruments from vital instrument bus (VIB) C to another VIB so that a loss of VIB C will not.result in the loss of high range main steam line radiation monitoring and a loss of all steam generator wide range level indication, also powered from VIB C.
- 2) A DCP will be developed in accordance with PSE&G approved procedures to lower the setpoints associated with the R46A-E warning alarms and the R46A-E high alarms to be 2
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reasonably consistent with the radiation levels experienced during actual SGTR events at other nuclear units.
- 3) Design Change Packages lSC-2154 and 2SC-2154, "Salem Unit 1 (2) Control Room Modification, Phase 2 11 have been issued and will implement the replacement of the non Class lE Steam Generator Narrow Range Level indicators, among others, with Class lE indicators.
This will result in the Steam Generator Narrow Range Level instrument loops being qualified for Category 1 service in accordance with the requirements of RG 1.97.
As stated in PSE&G Letter NLR-N89180, these modifications will be accomplished as soon as possible, however; in no case will the work be deferred beyond the tenth and sixth refueling outages for Salem Units 1 and 2, respectively.
These outages are presently scheduled for the Fall of 1991 and Spring of 1992.
To further assure the qualification and reliability of the functionally redundant set of instrumentation, the subject instrument loops will be reviewed for compliance to the SGS physical separation and electrical isolation criteria developed in accordance with Project Scope Proposal 126-89-0677, "Evaluation of Specific Instrument Loops Relative to Separation/Isolation Criteria and the Reg. Guide 1.97 Licensing Position, July 14, 1989 11
- As stated in PSE&G Letter NLR-N89180, the present schedule for this project calls for completion of the compliance review by November 1990.
The completion of the planned modifications, the in-progress compliance review, and the proposed procedural review/revisions will provide assurance that the detection of a SGTR and determination of the ruptured steam generator may be accomplished in accordance with; a) the Type A, Category 1 requirements of RG 1.97, b) the technical guidance provided by the Westinghouse Owners Group, and c) via instrumentation proven to indicate a SGTR steam generator during actual SGTRs.
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