ML20206H965

Application for Amend to License DPR-35,modifying Licensing Basis for EDG on-site Diesel Fuel Storage Requirement & Corresponding TSs

ML20206H965
Person / Time
Site:	Pilgrim
Issue date:	05/05/1999
From:	Ted Sullivan BOSTON EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20206H970	List: ML20206H965 ML20206H977
References
BECO-2.99.029, NUDOCS 9905120068
Download: ML20206H965 (8)

Text

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- 10 CFR 50.90 Boston Edison A BEC ENERGY COMPANY T.A. Sullivan Vice President Nuclear and Station Director May 5, 1999 BECo Ltr. #2.99.029 US Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 Docket No. 50-293 License No. DPR-35 Proposed License Amendment to Revise On-site Fuel Storace Reauirements for Emeroency Diesel Generators Boston Edison Company (BECo) hereby proposes to amend Pilgrim Operating License No.

DPR-35 in accordance with 10CFR50.90. The proposed amendment modifies the licensing basis for the Emergency Diesel Generator (EDG) on-site diesel fuel storage requirement and corresponding Technical Specifications (TS), as described below.

1. BECo proposes to modify the licensing basis for the Class i EDG on-site fuel storage requirement described in Pilgrim UFSAR 8.5, " Standby AC Power Source," to include Class ll Station Blackout Diesel Generator (SBODG) on-site fuel storage tanks described in UFSAR 8.10, " Blackout AC Power Source," to provide sufficient fuel for continuous seven days operation of both EDGs at rated loads.

The current licensing basis requires sufficient diesel fuel to be stored on-site in EDG main tanks for continuous operation of each EDG for approximately seven days. The corresponding volume considered at the time of licensing the plant was 19,800 gallons per EDG (TS 3.9.A.3). Design basis review confirmed 19,800 gallons per EDG was not sufficient for seven days of continuous operation (LER 98-021-00) and the cross-connection between the EDG tanks was determined to be susceptible to single failure (LER 98-001-00). Therefore, a licensing basis revision for EDG fuel storage is requested based on R.G.1.137, Rev.1 (10/79) and ANSI N195(ANS-59.51)-1976. The revised licensing basis requires 36,800 gallons of fuel per EDG to be stored on-site for continuous seven days operation of each EDG at the maximum bounding loads (2860 KW for 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> and 2750 KW for 166 hours0.00192 days <br />0.0461 hours <br />2.744709e-4 weeks <br />6.3163e-5 months <br />). Of this volume, a minimum of 19,800 gallons of fuel will be stored in each Class ! EDG tank and the balance will be stored in the Class 11 SBODG storage tanks.

2. Concurrent with the revised licensing basis proposed above, BECo proposes to modify TS 3.9.A.3 and 4.9.A.1.d specifying the total volume of diesel fuel required to be stored on-site in EDG Class I fuel system and Class !! SBODG fuel storage tanks. TS Bases B3.9 is revised to include the proposed licensing basis for the EDG on-site diesel fuel supply system augmented by the Class ll SBODG storage tanks.

9905120068 990505 " ^ I DR p ADOCK 05000293 PDR ~

7 I\I N 'd \j Pilgrim Nuclear Power Station, Rocky Hill Road, Plymouth, Massachusetts 02360

Thts rsvistd licensing basis rasolves ths EDG on-sits diassi fu:1 supply conc:ms discovnrad during ths dnsign basis ravi:w of EDGs and r: port:d in Licsnsa Evsnt Reports, LER 98-001-00, dated March 3,1998 and LER 98-021-00, dated October 2,1998.

Attachnyent A provides a description of the proposed License Amendment, safety assessment, snd no significant hazards consideration determination associated with the proposed change.

Attachment B contains the marked-up UFSAR and Technical Specification pages. Attachment C contains amended Technical Specification pages. UFSAR will be updated in accordance with 10 CFR 50.71(e) upon approval of the proposed license amendment.

We request NRC approval of the proposed license amendment by September 1,1999.

1 Should you have any questions regarding this letter, please contact Walter Lobo at (508) 830- l 7940. j

.A. Sullivan Commonwealth of Massachusetts)

County of Plymouth )

Then personally appeared before me, T.A. Sullivan, who being duly swom, did state that he is General Manager Production and Station Director 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 are true to the best of his knowledge and belief.

My commission expires: 6 edp/)eto,cAo '

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/ DATE NOTARY FJUBLIC i WGL/cis /  !

299029 ,

Attachment A: Description of Proposed Changes Attachment B: Marked-up UFSAR and Technical Specification Pages Attachment C: Amended Technical Specification Pages cc: Mr. Alan B. Wang, Project Manager Mr. Robert Hallisey i Project Directorate 1-3 Radiation Control Program l Office of Nuclear Reactor Regulation Commonwealth of Massachusetts Mail Stop: OWFN 8F2 Exec Offices of Health & Human Services U. S. Nuclear Regulatory Commission 174 Portland Street 1 White Flint North Boston, MA 02114 11555 Rockville Pike Rockville, MD 20852 U.S. Nuclear Regulatory Commission Mr. Peter LaPorte, Director Region l Mass. Energy Management Agency 475 Allendale Road 400 Worcester Road King of Prussia, PA 19406 P.O. Box 1496 Framingham, MA 01701-0313 Senior Resident inspector Pilgrim Nuclear Power Station 2

ATTACHMENT A - BECo Latter 2.99.029 DESCRIPTION OF PROPOSED CHANGE Proposed License Amendment ,

to Revise On-site Fuel Storace Reauirements for Emeraency Diesel Generators

1.

SUMMARY

OF PROPOSED CHANGE A change to operating license DPR-35 is proposed that would modify UFSAR Sections 8.5 and 8.10 to clarify the acceptable sources and quantities of diesel fuel to meet the on-site diesel fuel storage requirements for the Emergency Diesel Generators (EDGs). The proposed change modifies the EDG licensing basis for diesel fuel requirements in UFSAR Section 8.5 specifying the on-site diesel fuel stored in EDG Class I fuel system, augmented by the Class ll Station Blackout Diesel Generator (SBODG) storage tanks to permit operation of both EDGs at rated loads for seven days.

Changes to the Technical Specification (TS) are proposed to implement the above-modified on-site diesel fuel supply system for EDGs and SBODG. TS 3.9.A.3 and 4.9.A.1.d are modified to include the total volume of diesel fuel required to be on-site in the EDG Class I system and Class ll SBODG diesel fuel storage tanks. TS Bases B3.9 is revised describing the EDG and the SBODG on-site storage of diesel fuel supply system to ensure availability of diesel fuel for seven days operation of the EDGs for emergency conditions and operation of SBODG for SBO conditions.

2. REASONS FOR THE PROPOSED CHANGE Pilgrim Station is implementing a design basis information program for specific systems. During the design basis review process for the EDG system, the review showed additional electrical loads should be included on the EDGs. This led to a review of the corresponding fuel consumption calculation which revealed the calculation was based on assumptions that were different than those in UFSAR Chapter 14. A fuel consumption calculation based on UFSAR Chapter 14 assumptions demonstrated a single EDG will consume substantially more than 19,800 gallons over seven days and require the use of the fuel transfer cross-connect to transfer fuel from the idle EDG main storage tank. Further review revealed the fuel transfer cross-connect between the two EDG main storage tanks is vulnerable to single failure.

Subsequently, LER 98-001-00 was submitted addressing the cross-tie concern.

Additional review of EDG loading confirmed PNPS is designed to respond to abnormal transients and accidents with a single EDG (single loop of ECCS). Sufficient diesel fuel is currently available in the two EDG diesel fuel storage tanks to meet this requirement. However, if both EDGs are used to respond to an accident under TS 3.9.A.3, the 19,800 gallons fuel stored in each EDG tank is insufficient to ensure continuous operation of both EDGs for seven days in response to a DBA LOCA in accordance with UFSAR Chapter 14. This fuel supply concern for both EDGs operating within the requirement of TS 3.9.A.3 was subsequently addressed in LER 98-021-00.

Both EDG and SBODG fuel storage tanks are located on-site with sufficient fuel capacity for operating both EDGs and SBODG, BECo is proposing to credit the SBODG on-site fuel capacity to ensure both EDGs can operate continuously at rated load for seven days. This proposed change resolves diesel fuel supply concems included in LERs 98-001-00 and 98-021-00 and augments the diesel fuel supply system for the operation of both EDGs within the requirement of TS 3.9.A.3.

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3. PROPOSED LICENSING BASIS AND TECHNICAL SPECIFICATION CHANGE Licensina Basis Chance:

the cuirent licensing basis for the emergency diesel generators is described in UFSAR Section 8.5. The licensing basis for the station blackout diesel generator is described in UFSAR Section 8.10. TS 3.9.A.3 provides that both EDGs shall be operable and each EDG shall have a minimum of 19,800 gallons of diesel fuel on site. TS Bases B3.9. states that the 1 diesel fuel oil supply system for the EDGs consists of two (2) 25,000 gallons tanks to ensure a l minimum supply of 19,800 gallons in each tank. TS3/4.5.F.2 and B3/4.5.F provide the operability bases for the SBODG pursuant to License Amendment No.179.

The current licensing basis for EDG on-site fuel storage requirement is 19,800 gallons of fuel stored in EDG tanks. The 19,800 gallons of fuel per EDG was intended to be of sufficient capacity to meet the EDG fuel requirements for approximately seven days. During the review of the EDG design basis information, the 19,800 gallon volume per EDG was determined to be insufficient for seven day continuous operation (LER 98-021-00) and the cross-connection  ;

between the EDG tanks was determined to be non-single failure proof (LER 98-001-00).

Therefore, the licensing basis for the EDG on-site diesel fuel storage requirement is revised based on RG.1.137, Rev.1(10/1979) and ANSI N195(ANS-59.51)-1976.

1 The proposed licensing basis is 36,800 gallons of diesel fuel per EDG (73,600 gallons total) required to be stored on-site for continuous seven day operation at rated loads. Of this volume, a minimum of 19,800 gallons of fuel will be stored in each EDG Class I tank and the balance will be stored in the Class 11 SBODG on-site storage tanks. The total on-site fuel requirement of 73,600 gallons will support operation of both EDGs continuously for seven days at rated load. The fuel in the SBODG storage tanks will be available for refilling the EDG storage tanks to ensure seven day continuous operation of each EDG, as described below.

. The revised fuel consumption calculations show 35,725 gallons per EDG, which is rounded up for conservatism to 36,800 gallons per EDG, is required for seven day operation at the maximum bounding loads (2860 KW for two hours and 2750 KW for 166 hours0.00192 days <br />0.0461 hours <br />2.744709e-4 weeks <br />6.3163e-5 months <br />). Each EDG tank supplies 19,800 gallons of fuel to its diesel for approximately four days of operation at full rated load. The additional fuel supply to the EDG tanks from the SBODG tanks provides three days of fuel to operate the EDGs continuously for a total of seven '

days at rated loads.

. The refilling of the EDG tanks with fuel from the SBODG on-site storage tanks would be administratively controlled via a fuel management and transfer plan to ensure availability of diesel fuel to the EDGs. f uel transfer equipment will be available when needed to support fuel transfer from the SBO fuel storage tanks to either EDG storage tank. Administrative controls will be implemented to ensure the additional quantity of fuel is continuously available. Pilgrim is planning to use an air-driven pump and hoses independent of station electrical systems. This Class il equipment will remain staged and dedicated to emergency fuel transfer.

UFSAR Sections 8.5 and 8.10 are revised describing the proposed EDG on-site diesel fuel supply system augmented by SBODG fuel capacity. The SBODG diesel fuel is procured as "Q" and it is the same oil currently used in the EDG tanks. The diesel fuel stored in the EDG and SBODG tanks will continue to meet the fuel oit quality specified in ASTM 975-1981 standard. This revised description modifies the licensing basis for the EDG on-site diesel fuel supply system taking into account the administrative procedure for refilling the EDG storage tanks with diesel fuel from the SBODG storage tanks and the availability of the cross-connection between the EDG tanks to transfer diesel fuel from one EDG tank to the other when off-site replenishment is unavailable for greater than 4 days. This function is not required 4

to msst singla failura design requirements due to tha requirements impostd on thm SBO fus!

tanks and transfar equipmtnt.

1 Technical Specification Chanoe:

TS 3.9.A.3 and 4.9.A.1.d are revised stating the revised on-site diesel fuel storage capacity to assure operability of both EDGs. TS Bases B3.9 is revised describing the proposed EDG and l SBODG diesel fuel supply system and the fuel quantity requirement.

The marked-up pages of the UFSAR describing the EDG diesel fuel supply system and marked-up technical specifications are included in Attachment B, The proposed revisions to i the technical specifications are included in Attachment C. The UFSAR will be updated in i accordance with 10 CFR 50.71(e) upon approval of the proposed license amendment.

4. SAFETY ASSESSMENT OF PROPOSED CHANGE i PNPS has two EDGs that provide the standby AC requirements described in UFSAR Section 8.5. The safety objective for these diesels is to provide a Class IE, safety-related source of on-site AC power for the safe shutdown of the reactor following abnormal operational transients and postulated accidents. PNPS has one SBODG as described in UFSAR 8.10 to provide AC power during SBO transients pursuant to 10CFR50.63. TS 3/4.5.F.2 and B3/4.5.F provides SBODG operability bases requirements.

The current TS 3.9.A.3 requires that "Both diesel generators shall be operable" and "Each diesel generator shall have a minimum of 19,800 gallons of diesel fuel on site."  ;

RG.1.137, Rev.1, (10/1979), Regulatory Position 1.c, endorses ANSI N195-1976 standard and provides acceptable methods for determining the required on-site diesel fuel storage requirements to operate the minimum number of diesel generators continuously for seven days )

at rated capacity following the limiting design basis accident.

The diesel fuel consumption calculations performed in accordance with method (1) of Regulatory Position 1.c has shown the 19,800 gallons specified in the existing TS 3.9.A.3 is sufficient for approximately four days of continuous EDG operation at rated loads. The additional diesel fuel to be used for refilling the EDG storage tanks to provide for three

- additional days of continuous EDG operation is available on-site in the SBODG fuel storage tanks. The diesel fuel in the SBODG storage tanks meets the fuel quality requirement specified in Regulatory Position 2.a. Both EDG and SBODG diesel fuel storage tanks are located on-site in accordance with TS 3.9.A.3, with the combined capacity sufficient for continuous operation of both EDGs for seven days at rated loads. Accordingly, TS 3.9.A.3 and 4.9.A.1.d are revised specifying the total volume of diesel fuel required to operate both EDGs continuously for seven days based upon the revised fuel consumption calculations, the diesel fuel available in each EDG storage tank, and the diesel fuel available in the SBODG storage i tanks. Revised surveillance 4.9.A.1.d provides verification there is a sufficient inventory of diesel fuel on-site in the EDG and SBODG storage tanks to support each EDG operation for seven days at full load. The seven-day period is sufficient time to place Pilgrim in a safe shutdown condition and replenish diesel fuel from an off-site location, in accordance with

.RG.1.137. TS Bases B3.9 is revised describing the EDG and SBODG on-site diesel fuel supply system and quantities of diesel fuel required to be on-site.

The need for refilling the EDG storage tanks with diesel fuel from the SBODG storage tanks would not occur until after the fourth day of a postulated seven day requirement. This would allow more than enough time to plan and transfer the required quantity of fuel in the absence of off-site sources. Refilling of the EDG storage tanks with diesel fuel from the SBODG storage tanks will be controlled by appropriate administrative procedures. The required fittings and hardware accessories will be provided to ensure diesel fuel can be supplied to the EDG storage tanks from the SBODG storage tanks under the most severe environmental conditions 5

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expect:d at tha facility. Th3 most savara environm:ntal condition expretad at the facility during a d sign bIsis accid:nt condition (LOCA with LOOP)is tha radiological exposura dus to l accioent releases. Radiologicel exposure to the crews involved in refilling the EDG tanks with diesc! fuel from SBODG storage tanks is not expected to exceed the applicable guidelines or limits. A dose evaluation concluded it would be possible to install the transfer equipment and  !

conduct the fuel transfer operation after day 3 (post-LOCA) without exceeding the GDC 19 limits. Sources of toxic hazardous materials at the facility have been previously evaluated and are controlled. Therefore, environmental conditions during a toxic gas release would not I preclude the transfer of diesel fuel.

The SBODG storage tanks (40,000 gallons capacity total) are maintained in accordance with NRC guidance published in Generic Letter 85-06, in compliance with 10 CFR 50.63 requirements. These Class 11 tanks are rugged, double-wall fiberglass tanks. While not designed to safety-related requirements, the failure of these tanks under extreme environmental conditions, such as an earthquake, has been evaluated to be very unlikely. No permanently attached piping is needed for the refilling operation. The required fittings and hardware accessories for refilling operations are prestaged. Therefore, the SBODG diesel fuel storage tanks will be available to provide an additional source of diesel fuel for refilling the EDG tanks, as necessary.

As stated above, the total on-site diesel fuel requirement of 73,600 gallons is sufficient to support continuous operation of both EDGs for seven days. The use of the SBODG storage  !

tanks to augment the EDG fuel supply and the refilling operation are feasible under extreme  !

environmental conditions.

The probability of concurrent events is low (i.e., LOCA, sustained loss of off-site power greater l than 4 days, inability to replenish fuel from off-site sources during a nuclear emergency, inability to manage fuel in the Class I tanks through EDG load management, etc.) to the extent it is reasonable to credit reliable Class 11 equipment for supplying approximately 3 days of fuel for operation of each EDG. This conclusion is further substantiated by the fact only one EDG is -1 required to mitigate the consequences of a DBA LOCA yet the seven day on-site fuel requirement will be met for both EDGs.

UFSAR Section 8.5 describes the safety design bases for the standby AC power source. This section is revised describing the revised licensing basis and resolves inconsistencies reported  !

in LERs 98-001-00 and 98-021-00. UFSAR Section 8.10 is revised indicating the SBODG fuel storage tanks are used to augment EDG fuel supply for continuous seven days operation of both EDGs.

5. CONCLUSIONS j

implementing this change to approve the use of the additional quantity of on-site stored fuel to i meet the EDG fuel requirements will improve operational flexibility. The use of 34,000 gallons of existing on-site stored fuel from the SBODG fuel tanks would provide a total capability of 73,600 gallons which, as previously stated, is more than enough fuel to run both EDGs at rated load continuously for seven days.

6. COMMITMENTS TO IMPLEMENT THE LICENSING BASIS AND TECHNICAL SPECIFICATION CHANGES The proposed licensing basis and technical specification changes require the implementation of an administrative procedure for the refilling operation to transfer diesel fuel from the SBODG storage tanks to the EDG storage tanks and changes to the operating procedures, maintenance, and design bases documentation. The administrative procedure for refilling EDG tanks includes the required fittings and hardware accessories for refilling operations and prestaging of the refilling operation. Pilgrim is planning to use an air-driven pump independent of station electrical systems and hoses all of which will remain staged. These procedural 6

chang s will b3 complet:d and impismanttd within 30 days upon approval of tha propossd lic';nsa emindmint.

7. SCHEDULE OF CHANGE This proposed change, including the training of operators and administrative procedure for refilling operation, will be effective within 30 days of receipt of approval from the NRC.

8. DETERMINATION OF NO SIGNIFICANT HAZARDS CONSIDERATION BECo has evaluated the proposed licensing basis and technical specification changes and has determined that they involve no significant hazards. This determination has been performed in accordance with the criteria set forth in 10 CFR 50.92. The following analysis is provided in accordance with the 10 CFR 50.91 and 10 CFR 50.92 for the proposed amendment.

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

The proposed change affects only the on-site diesel fuel storage capacity for the operation of emergency diesel generators. The on-site storage capacity is not associated with an accident precursor / initiator; thus, it has no impact on the probability of accident occurring. The consequences of an accident would not be significantly increased because reasonable measures will be available to ensure the EDGs are supplied with enough fuel from the on-site sources to operate for seven days at rated capacity.

b. The proposed amendment does not create the possibility of a new or different kind of accident from any accident previously evaluated.  ;

The proposed change does not affect normal plant operation or the immediate response to an accident. The only change is the proposed refilling operation to transfer fuel from the Class ll SBODG storage tanks to the Class l EDG tanks. The refilling operation would occur entirely outdoors through above ground hoses connecting the EDG and SBODG tanks. This operation would only be required following a LOCA, an accident already analyzed. Since the proposed ,

refilling operation is a post-accident evolution, it would not be in place to cause an accident of I a different type during non-accident conditions. No reasonable malfunction of equipment associated with the evolution could create a new or different kind of accident than previously evaluated.

c. The proposed amendment does not involve a significant reduction in the margin of safety.

The proposed amendment for licensing basis change and TS change does not significantly reduce the margin of safety. The proposed change restores the licensing basis to provide sufficient fuelin on-site storage tanks for continuous operation of each EDG for approximately seven days. The revised licensing basis requires 36,800 gallons of fuel per EDG to be stored on site. A minimum of 19,800 gallons of fuel will be stored in Class l EDG storage tanks and the remaining will be stored in Class ll SBODG on-site storage tanks. The storage of fuel in Class I tanks does not reduce the margin of safety. The only potential reduction in the margin of safety is due to the use of Class ll SBODG tanks and associated transfer equipment for the storage and transfer of additional fuel. These Class ll tanks are rugged, double-wall fiberglass t

tanks. While not designed to safety-related requirements, the failure of these tanks under extreme environmental conditions, such as an earthquake, has been evaluated to be very unlikely. Thus, on-site storage of sufficient fuel for operation of both EDGs is assured to mitigate the consequences of an accident previously evaluated. All stored fuel is maintained at the same quality standard. The proposed diesel fuel refilling operation is a post design basis accident activity, which does not create the possibility of a new accident or impact an accident previously evaluated. Therefore, there is no significant reduction in the safety margin.

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Conclusion:

Th3 propos1:d changa represants-incraastd on-sito diesel fuel capacity for continuous operation of both emergency diesel generators at rated loads and improves the plant's capability to respond to previously evaluated accidents.

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