BECO-88-073, Provides Addl Info Re ATWS Alternate Rod Injection Instrumentation Calibr Frequencies,Per NRC 870924 Request to Complete Review of 870520 Application for Amend to License DPR-35.W/seven Oversize Drawings

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Provides Addl Info Re ATWS Alternate Rod Injection Instrumentation Calibr Frequencies,Per NRC 870924 Request to Complete Review of 870520 Application for Amend to License DPR-35.W/seven Oversize Drawings
ML20151W651
Person / Time
Site: Pilgrim
Issue date: 04/27/1988
From: Bird R
BOSTON EDISON CO.
To:
NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
Shared Package
ML20151W655 List:
References
BECO-88-073, BECO-88-73, NUDOCS 8805030449
Download: ML20151W651 (11)
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BECo Proposed Change 87-07  ;

i 8057tWEDd5CW Executiw Ofhces 800 Boyiston Street Boston, Massachusetts 02199 ,

I BECo 88 073 Proposed Change 88- ,

Senxx vee President - Nuclear April 27, 1988 U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 License DPR-35 Docket 50-293 REOUEST FOR ADDITIONAL INFORMATION-ATHS RPT/ARI

References:

1. NRC Letter, R. Hessman (NRC) to R. Bird (BECo), September 24, 1987, subject: "Proposed Technical Specification Change to Table 4.2.G Maximum Test and Calibration Frequency for ATHS RPT/ARI Instrumentation and 4.2.G Bases" (TAC 65493).
2. "Proposed Technical Specification Change to Table 4.2.G", BECo Letter 87-087, dated May 20, 1987.

Dear Sir:

j This letter provides the additional information requested by the NRC in '

Reference 1 to complete their review of a proposed Technical Specification Change (Reference 2) related to ATHS Alternate Rod Injection (ARI)  ;

instrumentation calibration frequencies.

The Attachments 1-3 address the three specific issues requested by the NRC.

They are an endorsement of BHROG Generic Response (NEDE-31096-P) to the ATHS  !

Final Rule, compliance with the ATHS Rule requirement related to the ARI, and (

a BECo initiated Safety Enhancement Program modification to the Recirculation Pump Trip function.

With the submittal of this additional information, we request expeditious NRC -

approval of the proposed Technical Specification change to support our restart  !

effort.

7 dc I G Bird HGL/jcp/1895  !

Attachments: 1. Request No. I j

2. Request No. 2
3. Request No. 3 cc: On next page I Ad b D R AWSS T#
  • R e(r [i (g 8805030449 eon 880427,3 aDoCx 050002  ;

P DCD r

BOSTON EDISON COMPANY April 27 1988 U. S. Nuclear Regulatory Comission Page 2 cc: Mr. O. Mcdonald, Project Manager Division of Reactor Projects I/II Office of Nuclear Reactor Regulation Mail Stop: 1401 U. S. Nuclear Regulatory Comission

] 1 White Flint North 11555 Rockville Pike R Rockville HD 20852 U. S. Nuclear Regulatory Comission Region I 475 Allendale Road King of Prussia, PA 19406 Senior NRC Resident Inspector Pilgrim Nuclear Power Station e'

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ATTACHMENT 1 TO BECO 88 073 RE00EST NO. 1 NRC Reauest Confirm that the phrase in your [[letter::BECO-86-049, Responds to ATWS Final Rule 10CFR50.62.Licensing Topical Rept NEDE-3196-P Provides Sufficient Info Re Adequacy of ATWS Mods|April 23, 1986 letter]] ".. endorses...as applicable to PNPS..." is properly interpreted to mean that the identified Licensing Topical Report is applicable in 111 entirety.

BECo Response BECo endorses the GE Licensing Topical Report NEDE-31096-P "Anticipated Transients Without Scram; Response to NRC ATHS Rule, 10CFR50.62" in its entirety with the exception of the ARI 15/25 Seconds Initiation / Completion Time Requirements.

For a discussion relating to this exception, see Item 1 of the Appendix A response in Attachment 2 to this letter.

Page 1 of 5 i

I ATTACHMENT 2 TO BECO 88- 073 i

BIQUEST NO. 2 l i

i NRC Reauest Provide the information indicated in the checklist attached as Appendix A to Safety Evaluation of Topical Report (NEDE-31096-P) "Anticipated Transient Nithout Scram; Response to ATHS Rule 10CFR50.62". A copy of the Safety Evaluation is enclosed for this purpose.

BEco Response See the following pages for a completed Appendix A.

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Attachment 2 Page 2 of 5 APPENDIX A CHECKLIST FOR PLANT SPECIFIC REVIEW OF ALTERNATE R00 INJECTION SYSTEM (ARI)

Conformance with ARI SER

1. ARI system function time Rod injection motion will begin within 15 seconds No and be completed within 25 seconds from ARI initiation See Note 1
2. Safety-related requirements (a) Class IE isolators are used to interface with Safety-related systems Yes (b) Class 1E isolators are powered from a Class IE source Yes (c) Isolator qualification documents are No i available for staff audit See Note 2 .
3. Redundancy The ARI system performs a function redundant '

to the backup scram system Yes  ;

4. Diversity from existing RTS  !

(a) ARI system is energize-to-function Yes (b) ARI system uses DC powered valves Yes (c) Instrument channel components (excluding sensors but including all signal conditioning and isolation devices) are diverse from the Yes existing RTS components. See Note 3 l S. Electrical independence from the existing RTS (a) ARI actuation logic separate from RTS logic Yes (b) ARI circuits are isolated from safety related Yes  !

circuits

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Attachment 2 Page 3 of 5

6. Physical separation from the existing RTS (a) ARI system is physically separated from RTS Yes See Note 4
7. Environmental Qualification ARI equipments are qualified to conditions during an Yes ATHS event up to the time the ARI function is completed See Note 5
8. Quality Assurance (a) Comply with Generic Letter 85-06 Yes See Note 6
9. Safety-related power supply (a) ARI system power independent from RTS Yes (b) ARI system can perform its function during any loss-of-offsite power event Yes
10. Testability at Power '

(a) ARI testable at power Yes (b) Bypass features conform to bypass NA, mhintenance criteria used in RTS bypass not used i

11. Inadvertent Actuation  ;

(a) ARI Actuation setpoints will not challenge scram Yes (b) Coincident logic is utilized in ARI design Yes

12. Manual Initiation (a) Hanual initiation capability is provided Yes i
13. Information Readout  ;

(a) Information readout is provided in main control room Yes

14. Completion of protective action once it is initiated Yes See Note 7  :

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Attachoent 2 Page 4 of 5 ,

1 Note 1 Pilgrim does not meet this requirement, but the function time is acceptable based on the following. GE Topical Report NEDE-31096-P states that deviation from the 15 and 25 second rod insertion motion can be shown to be acceptable basedontheassessmentsofthedesignca,jectivesandplantuniqueScram Olscharge Volume (SOV) fill time calculations. The most limiting design objective is that the ARI function be complete before the pressure suppression pool (PSP) temperature reaches 110*F. This design objective will be met 1 provided full rod insertion occurs within approximately 60 seconds of ARI I initiation, based on NEDE-31096-P. Therefore, as long as calculations of ARI test results can show that Pilgrim Plant SDV fill time is not more bounding, deviations from the 15 and 25 second rod insertion motion should be allowed.

The results of the GE evaluation of Pilgrim's ARI System (NEDE-30958) indicate 1

that the SDV can still maintain sufficient capacity up to a 50-sec time delay and still permit all control rods to reach their full-in position given the following assumptions:

1 a. Rod insertion distribution is based on the Pilgrim test data.

b. Leakage rate of 5 gpm per drive (NED0-24342).
c. The Scram Olscharge Instrument Volume is empty.
d. The vent and drain valves are open during the scram duration as indicated by the test data.

Actual ARI tests performed at Pilgrim confirm that the final rod started motion in less than 50 seconds from the ARI initiation and, therefore, the j requirements for Scram Discharge Volume considerations are met. From the time

!' of the final rod starting motion, an additional 3 to 7 seconds is required for the scram to be completed. This yields a conservative final time of 57 seconds for all rods being inserted by the ARI system at Pilgrim and this meets the 60 seconds requirement for the most limiting design objective

(suppression pool temperature) as stated above.

To demonstrate continued performance of ARI system, surveillance tests are conducted in accordance with the Technical Specifications.

Note 2 '

Only seismic test report data and manufacturer's specifications are available.

Note 3 The ATHS Rule requires that ARI system M be diverse from the existing reactor ,

trip system. The NRC guidance on the ATHS Rule states that equipment i diversity to the extent reasonable and practicable to minimize the potential l for common cause failures is required from the sensors to and including the i components used to interrupt control rod power or vent the scram air header.

t The Alternate Rod Insertion / Recirculation Pump Trip Systems are consistent with the "Monticello RPT/ARI" design described in NED0-25016 as referenced by the NRC as an acceptable design in NUREG-0460 for RPT. NED0-25016 provides

both system description and performance analysis (See BECo response to Request
  1. 3). t

Attachment 2 Page 5 of 5 In 1980 Boston Edison installed the ARI/RPT. BECo selected the GE Analog Transmitter / Trip Unit system to detect the reactor water level and pressure for ATHS event. Notice of NRC acceptance of Analog Transmitter / Trip Unit system for engineered safeguard transmitter trip unit (NE00-21617-A) was issued on June 27, 1987.

Alternate rod insertion utilizes the sama initiation logic and functions as RPT and provides a diverse means of initiating a reactor scram.

The ARI instsument channels are diverse to the extent that they are energized-to-initiate, whereas the RPS channels are de-energize-to-initiate.

The sensors and trip units, although separate and independent for each system, are the same type in both systems. The final trip relays are of different manufacture, but the RPS system uses interposing relays which are of the same manufacture as the final trip relay used in the ARI system. The solenoid valves used to vent the scram air header for the ARI system. The solenoid valves used to vent the scram air header for the ARI system are "energize-to-vent", whereas the solenoid valves used for the RPS are "de-energized-to vent". The ARI solenoid valves are DC powered and the RPS solenoid valves are AC powered.

Note 4 Internal ATHS Panel separation is per GE design. RTS (RPS) is installed totally in conduit - ARI is also installed in conduit and is physically separated from RPS. The ARI instrument system is electrically independent of the RPS system. The systems are mechanically independent except for the use of the same instrument sensing lines and the same scram air header.

Note 5 The BWR Owner's Group report called for environmental qualifications of equipment to temperature, pressure, humidity and radiation levels associated with Anticipated Operational Occurences. The NRC staff in its SER stated, "Equipment must be qualified to conditions during an ATHS event up to the time that the ARI function is completed". Boston Edison considers this to be a mild environment.

Note 6 Modifications to ATHS ARI/RPT systems, subsequent to issuance of GL 85-06, are treated as Q to the extent practicable and in accordance with the revised QA measures put into place as a result of GL 85-06. The original ARI/RPT modification installed in 1980 was not considered overall as safety related.

Portions of the electrical systems that interfaced with safety related systems were isolated from safety related systems with Class IE isolators and controlled according to QA practices in effect at the time of the modification.

60.tL1 The ARI system has been designed so that once it is initiated, the protective action will go to completion. Either the automatic or manual actuation signals in the generic ARI system design "",eal-in" to assure that all control rods have time to fully insert.

The reset of the ARI function is automatic after an adequate time delay to allow rod insertion and the initiations signals have cleared.

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ATTACHMENT 3 TO BECO 88- 073 l l

i REQUEST No. 3  !

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NRC Request

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Supplement the information in the 7/8/87 Safety Enhancement Program letter  !

with a description and analysis of the Recirculation Pump Trip Modification, i Also please provide the related RPT Logic Diagram, j BEco Response Oriainal ATHS RPT Modification  !

In BECo letter 79-69, dated April 10, 1979. Boston Edison Company committed "... to install...and make operational an ATHS RPT of the 4 Monticello design by May 1980". In BECo letter 80-57, dated April 7, 1980 BECo proposed (in Attachment F) Technical Specifications for the ATMS RPT/ARI modifications. Attachment F addressed a RPT Limiting ,

Condition for Operation (LCO), surveillance' requirements as their bases, i and the bases for the RPT/ARI modifications. The attachment also included a three page discussion of the modification, the safety considerations [

associated with it, and design details to include changes from the Monticello design in the Pilgrim installation.

Proposed Page 73 of Attachment F discussed the purpose of the RPT  !

modifications and stated that the system descriptions and performance f analyses related to the Monticello type design are provided in NE00-25016 I "Evaluation of Anticipated Transients Nithout Scram for the Monticello i Nuclear Generating Plant", September 1976. Page 73 also stated the  !

Monticello design was accepted by the NRC in NUREG-0460. Volume 3, dated i December 1978. Proposed Page 77 discussed calibration frequencies of the  ;

associated RPT instrumentation, j t

The changes proposed in our April 7, 1980 letter were accepted by the NRC  ;

and issued as Amendment No. 42 to our operating Itcense on May 12, 1980, t The NRC safety evaluation report contained in the letter addressed the RPT [

modification on pages 24-27. A favorable final safety evaluation report  ;

on the RPT/ARI section of Amendment No. 42 was transmitted by the NRC in a  !

letter from T. Ippolito to A. Morist dated February 19, 1981. The safety t evaluation stated the Technical Specifications changes "...are in i conformance with the requirements of volume 3 of NUREG-0460. The  !

differences between the Pilgrim and Monticello RPT/ARI systems are also i acceptable'. The RPT language from Amendment No. 42 is still found in our i current Technical Specifications at Sections 3.2 and 4.2. {

Based on the above, BECo believes it has adequately provided descriptions j and analysis references regarding our original RPT installation.  ;

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Attachment 3  !

Page 2 of 2 Additional RPT Modificatisn [

1 1 In our July 8, 1987 Safety Enhancement Program (SEP) letter, we addressed

-! a recent voluntary (i.e., not required by regulation) RPT modification designed to provide an ATMS trip of the motor generator (M/G) drive motor breaker. This trip would supplement the existing RPT involving the M/G  :'

field breaker and is intended to enhance the reliability of the ATMS trip function, t Seven drawings (MIE6-6, M1YI, M1Y2, M1Y3, M1Y6, M1Y7 and M1Y12) that relate to the logic system involved with the modification are included as part of this i attachment. i I

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t SEE APERTURE CARDS NUMBLR OF OVERSIZE PAGES FlLMED ON APERTURE CARDS APERTURE CARD /HARD COPY AVAlJ' LBLE FROM RECORD SERVICES BRANCH,TIDC i FTS 492=3989 i

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