BECO-87-085, Application for Amend to License DPR-35,revising Tech Specs to Reflect Mods to Standby Liquid Control Sys,Per 10CFR50.62(c)(4) Requirements Re Atws.Description of Proposed Change Encl

Application for Amend to License DPR-35,revising Tech Specs to Reflect Mods to Standby Liquid Control Sys,Per 10CFR50.62(c)(4) Requirements Re Atws.Description of Proposed Change Encl

ML20214T628
Person / Time
Site:	Pilgrim
Issue date:	05/29/1987
From:	Bird R BOSTON EDISON CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
Shared Package
ML20214T629	List: BECO-87-085, Application for Amend to License DPR-35,revising Tech Specs to Reflect Mods to Standby Liquid Control Sys,Per 10CFR50.62(c)(4) Requirements Re Atws.Description of Proposed Change Encl ML20214T634
References
BECO-87-085, BECO-87-85, NUDOCS 8706100356
Download: ML20214T628 (6)

Text

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(M 10CFR50.90 aosionsorson Executive Offices 800 Boylston Street Boston, Massachusetts 02199 Ralph G. Bird Senior Vice President - Nuclear May 29, 1987 BECo 87-85 U. S. Nuclear Regulatory Commission Document Control Desk Hashington, DC 20555 License DPR-35 Docket 50-293

Subject:

Proposed Standby Liquid Control System Technical Specification Changes to Comply with the Anticipated Transient Hithout Scram (ATHS)

Rule, 10CFR50.62(c)(4) and Various Minor Administrative Changes.

Dear Sir:

This letter describes proposed modifications to the Pilgrim Nuclear Power Station (PNPS) Technical Specifications and License DPR-35 in response to the Anticipated Transient Hithout Scram (ATHS) Rule, 10CFR 50.62(c)(4). The proposed changes reflect modifications to the Standby Liquid Control System.

In previous correspondence (Reference 1), BECo provided a schedule for meeting the requirements of the rule. Subsequently (Reference 2), BECo endorsed the BWR Owner's Group (BHROG) ATHS Licensing Topical Report, NEDE-3196-P. This endorsement concluded that the Topical Report provided sufficient information regarding the adequacy of Pilgrim ATHS modifications. The NRC reviewed the Topical Report and issued a Safety Evaluation Report (Reference 3) to the BHROG concurring that the ATHS Rule was adequately addressed.

The Topical Report describes three alternative means for complying with the ATHS Rule requirements for the Standby Liquid Control System. Boston Edison Company (BECo) has selected the option of installing enriched boron injection capacity. The Technical Specification revisions associated with this modification are discussed in Attachment 1 to this letter. The actual page changes are included in Attachment 2 to this letter. The changes are in accordance with NRC clarification (Reference 4) to the original SER and the modifications will be implemented during Refueling Outage #7 with subsequent documentation to NRC.

8706100356 870529 PDR ADOCK 05000293 h0 3 P PDR U l

BOSTON EDISON COMPANY May 29, 1987 U. S. Nuclear Regulatory Commission Page Two In addition, a change is proposed to Technical Specification Table 6.9.1 to delete an outdated Inservice Inspection Reporting requirement.

i JL/ pac Attachment 1 - Description of Proposed Technical Specification Changes To Comply Hith the ATHS Rule Attachment 2 - Proposed Revised Technical Specification Pages

References:

(1) " Compliance with the ATHS Rule - Implementation Schedule, 10CFR50.62(d)," BECo letter #85-178, dated October 7, 1985.

(2) " Anticipated Transients Hithout Scram, Final Rule, 10CFR50.62, BECo Response," BECo letter #86-049, dated April 23, 1986.

(3) Acceptance for Referencing of Licensing Topical Report NEDE-31096-P, NRC Safety Evaluation of Topical Report, dated October 21, 1986.

(4) Generic Letter 85-03, Clarification of Equivalent Control Capacity for Standby Liquid Control Systems, dated January 28, 1985.

cc: See next page Commonwealth of Massachusetts)

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Then personally appeared before me, Ralph G. Bird, who, being duly sworn, did state that he is Senior Vice President - Nuclear of Boston Edison Company and that he is duly authorized to execute and file the submittal contained herein in the name and on behalf of Boston Edison Company and that the statements in said submittal are true to the best of his knowledge and belief.

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BOSTON EDISON COMPANY May 29, 1987 U. S. Nuclear Regulatory Commission Page Three cc: U. S. Nuclear Regulatory Commission Region I 631 Park Avenue King of Prussia, PA 19406 Mr. R. H. Nessman, Project Manager Division of Reactor Projects I/II Office of Nuclear Reactor Regulations U. S. Nuclear Regulatory Commission 7920 Norfolk Avenue Bethesda, MD 20814 Mr. Robert M. Hallisey, Director Radiation Control Program Mass. Dept. of Public Health 4

150 Tremont Street F-7 Boston, MA 02111 Senior NRC Resident Inspector Pilgrim Nuclear Power Station f

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ATTACHMENT 1 Descriotion of Proposed Technical Soecification Chanaes PROPOSED CHANGES The proposed changes to the Pilgrim Nuclear Power Station Technical Specification include surveillance requirements in Sections 4.4.A and 4.4.C, sodium pentaborate solution chemical characteristics in Section 3.4.C, deletion of Figure 3.4.2, changes to the bases, a change to Table 6.9.1, and changes to Figure 3.4.1. Several minor administrative changes resulting from page realignment and typographical corrections are also included. These changes are proposed to reflect the following Standby Liquid Control System (SLCS) modifications which are being made to comply with the ATHS Rule, 10CFR50.62(c):

(1) The sodium pentaborate solution in the SLCS will be replaced with enriched boron solution which will have the following characteristics:

(a) A minimum solution concentration of 8.42%, and (b) A baron enrichment of the sodium pentaborate decahydrate of over 54.5 B10 isotope atom percent.

(2) The SLCS surveillance testing will be changed to include a analysis to ensure that the isotopic concentration of the enriched boron solution meets or exceeds the above characteristics.

REASON FOR CHANGES The ATHS Rule,10CFR50.62(c), requires changes to the existing PNPS SLCS to meet ATHS conditions. These conditions are in addition to those required for safe shutdown under the conditions originally assumed for safety analyses.

The ATHS Rule specifically requires SLCS to have a minimum flow capacity and boron content equivalent in control capacity to 86 GPM at 13 wt % sodium pentaborate solution for a 251" diameter reactor pressure vessel. Specific control capacity required for other vessel diameters must be determined by analysis. The PNPS reactor pressure vessel diameter is 218". The equivalent control capacity injection rate was calculated by GE in NEDE-24222 to be 66 gpm at 13 wt % of naturally enriched sodium pentaborate solution. To meet the equivalent control capacity injection rate given the presently installed SLC pumping capacity of 39 gpm a minimum concentration of 8.42% sodium pentaborate solution with a B10 isotope enrichment of 54.5 atom percent is required. This limit is reflected in the proposed revised Figure 3.4.1.  :

The temperature / concentration requirements of existing Table 3.4.2 are no longer required because the curve extends down only to 9.4% sodium pentaborate concentration and is based upon naturally enriched sodium pentaborate. The proposed revised concentration limits allow a maximum concentration of 9.22%

sodium pentaborate. At 9.22% sodium pentaborate concentration, the temperature required to preclude sodium pentaborate precipitation (with a 10*F margin) is 48'F. The controlled building temperatures make it improbable that the SLC solution will approach this limit, and system alarms provide operator I notification of such a potential event. Because of the 10'F margin to l potential sodium pentaborate precipitation at monitored concentration levels, '

the 48'F temperature limit provides the same protection considered in the original safety evaluation. The 48'F temperature limit preempts the previous temperature - concentration curve provided in Figure 3.4.2. Accordingly, it is proposed that the existing Figure 3.4.2 be deleted.

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.' Additional Specificationssurveillance to ensurerequirerent;Ohave beenenrichment.

adequate B' isotopic inserted in the Techniggi Because Biu is a i stable isotope, the enrichment of the SLC solution could change only if 1

.require additional boron were evaluation of B aged to the solution. These additional surveillances-enrichment upon receipt of sodium pentaborate, j whenever boron is added to the SLC solution, and during each rgfueling i outage. This surveillance also integrates the evaluation of B'O enrichment 1

with the evaluation of the original design assumptions regarding natural boron-l concentration / volume. The surveillance requirements have been added to meet the requirements of the NRC generic safety evaluation report (SER)'(Reference -

i 3). For an enriched boron solution, the SER has concluded that surveillance and positive verification by periodic testing will assure that the correct isotopic enrichment as well as sodium pentaborate concentration are maintained.

l Minor administrative changes are also proposed to maintain page continuity and j correct typographical errors. In addition, it is proposed that item (b) of 4 a Technical Specification Table 6.9.1 be deleted. This specification requires i submittal of a report evaluating the ISI Program five years after commencement

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of commercial operation. This report has already been submitted ("Five Year Evaluation of ISI Program", BECo letter 78-8, dated 1/17/87). Therefore, the specification can be deleted with no safety impact to the plant.

l SAFETY EVALUATION AND DETERMINATION OF NO SIGNIFICANT HAZARDS CONSIDERATION

! The proposed changes in the Standby Liquid Control System are implemented to i comply with the requirements of 10CFR50.62. In accordance with 10CFR50.59, a

safety evaluation to support the proposed changes to the SLCS has been i completed. -

i The Code of Federal Regulations, 10CFR50.91, requires that at the time a

! licensee requests an amendment, it must provide to the Commission its

analysis, using the standards in 10CFR50.92, about the issue of no significant hazards consideration. Therefore, in accordance with 10CFR50.91 and

10CFR50.92, the following analysis is provided

1. The operation of PNPS in accordance with the proposed amendment will not involve a significant increase in the probability or consequences of an

accident previously evaluated.

The addition of enriched boron will provide a shutdown margin equivalent to the previously calculated shutdown reactivity control capability.

Therefore, the proposed amendment does not involve a significant increase in the probability or consequences of an accident previously evaluated.

I i 2. The operation of PNPS in accordance with the proposed amendment will not l

, create the possibility of a new or different kind of accident from any i accident previously evaluated.

The proposed changes involve a system whose only function is to provide a backup shutdown capability. The proposed changes do not affect a system or component which could initiate an accident. There are no other systems

! or subsystems that interact with the SLCS which could initiate an

! accident. Therefore, the amendment does not create a new or different kind of accident.

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3. The operation of PNPS in accordance with the proposed amendment will not involve a significant reduction in the margin of safety.

The proposed changes in the SLCS decrease the required sodium pentaborate gining an equivalent overall shutdown reactivity concentration capability. Thewhile totalmain B {u isotope injection capability will be significantly higher than required for the original design basis, and reactor shutdown will be ach eved at a much faster rate. The proposed changes increase the total B u isotope injection into the reactor pressure vessel, thereby increasing the shutdown margin for Anticipated Transient Without Scram events. Therefore, the margins of safety are not reduced by this change.

For the reasons provided above, Boston Edison Company believes that this proposed amendment does not present a significant hazards consideration, does not invalidate the original design basis of the SLCS, and does not present an unreviewed safety question as defined in 10CFR50.59. The proposed change has been reviewed and approved by the Operations Review Committee and reviewed by the Nuclear Safety Review and Audit Committee.

Schedule of Chance It is requested that the proposed amendment become effective subsequent to receipt of approval by the Commission, and upon notification by the Licensee to allow transition between requirements imposed by the original volume /

concentration curve and the revised curve based upon increased B-10 isotopic enrichment. l FEE DETERMINATION In accordance with 10CFR170.12, a check for $150.00 will be electronically mailed to your office.

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