ML20205T203

Application for Amend to License NPF-43,changing Div I Degraded Grid Voltage Trip Setpoints to Correspond to Min Voltage Necessary to Protect Class 1E Equipment.Fee Paid

ML20205T203
Person / Time
Site:	Fermi
Issue date:	06/11/1986
From:	Agosti F DETROIT EDISON CO.
To:	Adensam E Office of Nuclear Reactor Regulation
Shared Package
ML20205T207	List: ML20205T203 ML20205T208
References
VP-86-0065, VP-86-65, NUDOCS 8606130073
Download: ML20205T203 (12)

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C#3 Edison 555FN w g,s, June 11, 1986 VP-86-0065 Director of Nuclear Reactor Regulation Ms. Elinor G. Adensam, Director Project Directorate No. 3 Division of BWR Licensing U. S. Nuclear Regulatory Commission Washington, D. C. 20555

Reference:

1) Fermi 2 NRC Docket No. 50-341 j NRC License No. NPF-43

2) Detroit Edison to NRC Letter, " Intent to Request an Emergency Amendment to the Fermi 2 Technical Specifications Governing Emergency Core Cooling System Actuation Instrumentation Setpoints",

VP-06-0066, dated June 7, 1986

Subject:

Request for an Emergency Amendment to Fermi i- 2 Technical Specifications Governing ,

Emergency Core Cooling System Actuation Instrumentation Setpoints

' In accordance with 10CFR50.91 Detroit Edison requests an emergency amendment to the Fermi 2 Technical Specifications that would alter the degraded grid relay setpoints for Division I. The requested amendment would change the setpoint values for the Division I degraded l grid relays in Table 3.3.3-2, item 5.b. The proposed change is necessary to allow Division I to be declared operable.

A safety evaluation with a no significant hazards consideration determination has been performed. Detroit Edison has determined that the proposed change to the Fermi 2 Technical Specifications involves no significant hazards consideration. The complete significant hazards analysis is attached.

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Ms. Elinor G. Adensam June 11, 1986 VP-86-0065 Page 2 To permit continued outage work, the Technical Specifications require one Division of onsite power (EDGs) to be operable in our current operational mode, mode 5. 'Divisicn II is currently operable. Division I, therefore, is not currently required. Modifications to the Division I ECCS actuation instrumentation setpoints will be completed prior to an operability declaration.

The setpoint modification cannot begin until the revised Technical Specification figures are approved.

The degraded grid voltage condition was identified during a recent update of degraded grid relay design

. calculations. The revised calculations indicate that Division I setpoints should be changed to correspond to the minimum degraded grid voltage necessary to protect l Class IE equipment.

The potential undervoltage condition was identified on May 27, 1986. Subsequent receipt of equipment vendor information confirmed the existence of an unacceptable degraded grid voltage. A Deviation / Event Report (DER) was then issued on June 4, 1986. The Nuclear shift Supervisor (NSS) determined the condition to be reportable in accordance with 10CFR50.72 and informed the NRC of the condition at 1202 hours0.0139 days <br />0.334 hours <br />0.00199 weeks <br />4.57361e-4 months <br /> the same day.

Notification was made via the Emergency Notification System. Detroit Edison has fervently pursued the correct and expeditious resolution of this issue.

The Fermi 2 restart schedule requires Division I to be operable on, or before, June 15, 1986, so that Division 4

II work may begin. The Division II work is critical path for the scheduled restart. The documentation required to incorporate the new setpoints in the l

Division I undervoltage relays will be available on or before June 13, 1986. However, the amended Technical

. Specification must be approved prior to the commencement l of the Division I setpoint modification. The setpoint j modification and subsequent Division I operability are

required prior to the commencement of Division II work.

In accordance with 10CFR50.91 the State of Michigan has been copied on this letter as well as the referenced letter, VP-86-0066, dated June 7, 1986. Fermi 2 will attempt to communicate the request for an emergency Technical Specification change and the circumstances leading to this request. The communication will be made by Fermi 2 Licensing in the form of a telecon.

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Ms. Elinor G. Adensam June 11, 1986 VP-86-0065 Page 3 Attachment 1 provides the technical justification for, and environmental effect of, the proposed Emergency Technical Specification amendment, Attachment 2 is the significant hazards analysis, Attachment 3 is the Technical Specification impact on restart, and Attachment 4 is a copy of the affected Fermi 2 Technical Specifications with the proposed changes indicated.

Detroit Edison has evaluated this amendment request in accordance with the criteria in 10CFR170.21 and has enclosed an application fee of one hundred and fifty dollars ($150.00) as initial payment for this application for amendment under Facility Category A (Power Reactors).

Should you have any questions concerning this amendment, please contact Mr. R. L. Woolley (313) 586-4211.

Sincerely, l --f?[ ,

Y cc: Mr. M. D. Lynch Resident NRC Inspector Supervisor, Advance Planning and Review Section Michigan Public Service Commission USNRC Document Control Desk Washington, D. C. 20555

Ms. Elinor G. Adensam June 11, 1986 VP-86-0065 Page 4 I,. FRANK E. AGOSTI, do hereby affirm that the foregoing statements are based on facts and circumstances which are true and accurate to the best of my knowledge and belief.

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FRANK E. AGiOSTI Vice President Nuclear Operations On this O day of A , 1986, before me personally appeared Frgfrk E. Agosti, being first duly sworn and says that he executed the foregoing as his free act and deed.

Notary Public MARCIA BUCK Notary Public, Washtenaw County, MI My Commission Expires Dec.23,1937 db y, W

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ATTACHMENT ONE: TECHNICAL JUSTIFICATION l Technical Specification Affected Emercency Core Coolina System Actuation Instrumentation 3/4.3.3 o Emergency Core Cooling System Actuation Instrumentation Setpoints for Division I - Table 3.3.3-2 Amendment Request The proposed amendment changes the Division I Degraded Grid Voltage trip setpoints and allowable values for the 4.16 kv Emergency Bus Undervoltage relay settings to correspond to the minimum degraded grid voltage necessary to protect the Class IE equipment in Division 1.

Discussion Requirements The emergency core cooling system actuation instrumentation is provided to initiate actions to mitigate the consequences of accidents that are beyond the ability of the operator to control.

Branch Technical Position PSB-1 " Adequacy of Station Electric Distribution System Voltages" requires that, in addition to the undervoltage scheme provided to detect loss of offsite power at the Class IE buses, a second level of undervoltage protection with a time delay should be provided to protect the Class IE equipment; this second level of undervoltage protection shall satisfy the following criteria:

I a) The selection of undervoltage and time delay setpoints shall be determined from an analysis of the voltage requirements of the Class IE loads at all onsite system distribution

levels; b) Two separate time delays shall be selected for the second level of undervoltage protection based on the following conditions:

1) The first time delay should be of a duration that establishes the existence of a sustained degraded voltage condition (i.e., something longer than a motor starting transient). Following this delay, an alarm in the control room should alert the operator to the degraded condition. The subsequent occurrence of a Safety Injection Actuation Signal (SIAS) should

immediately separate the Class IE distribution system from the offsite power system.

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2) The second time delay should be of a limited duration such that the permanently connected Class 1E loads will not be damaged. Following this delay, if the operator has failed to restore adequate _ voltages, the Class lE distribution system should be automatically separated from the offsite power system.

c) The Technical Specifications shall include limiting conditions for operations, surveillance requirements,. trip setpoints with minimum and maximum limits, and allowable values for the second-level voltage protection sensors and associated time delay devices.

Fermi 2 Compliance Detroit Edison letters EF2-53522, dated June 11, 1981 and EF2-53888, dated June 26, 1981 provided an initial point-by-point discussion cf our undervoltage protection scheme with reupect to the NRC's Branch Technical Position, PSB-1, " Degraded Grid Protection". The Fermi 2 response to Degraded Grid Conditions is discussed in FSAR section 8.2.2.5.3 and in response to NRC item 222.31A, PSAR Appendix E.5. Subsequently, updated values were i incorporated in our draft Technical Specifications reviewed by the NRC and issued as approved Technical Specifications.

4 An NRC inspection of the Electrical Distribution System was conducted by your Mr. A. Saeed on June 23, 1981. In accordance

with FSAR Appendix E.5, item 222.31A Fermi 2 has installed the second level of undervoltage relaying to sense the degraded grid condition and the specific features of the design are as follows:

a) The undervoltage relays are set in accordance with design calculations to preclude damage to Class IE equipment. A time delay setting was chosen to avoid the operation of the j relay during motor starting conditions.

The design calculations used to determine undervoltage relay setpoints to ensure adequate voltage requirements of the Class IE loads at all onsite system distribution levels were recently updated to include changes in equipment, power loads and assumptions. Updated voltage requirements for the 480 volt class IE buses were determined by Design Calculation 968, Intermittent Duty Motor Fuse and Thermal Overload Sizing and Design Calculation 969, Continuous Duty Motor Fuse and Thermal Overload Sizing. The results of

Design Calculations 968 and 969 were incorporated in Design Calculation 835, Degraded Grid Voltage as lower voltage

limits for the 480 volt buses. The limiting voltage for the i 4160 volt buses from Design Calculation 835 were then used

! in Design Calculation 919, Undervoltage Relay Setpoints, to

! determine the new required degraded relay settings as i reflected in the proposed Technical Specification change.

Although the calculations apply to both Division I and Division II Class IE equipment, only Division I requires recetting.

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. From these calculations it was determined that the degraded grid relay setting for Division 1 should be increased to.95% of nominal (3952 volts on the 4.16 kv basis). The current relay setting is 89% of nominal (3702 volts on the 4.16 kv basis).

1 The reason for the setpoint change is the result of changing two assumptions used in the design calculations: 1) Motor Operated

Valves were assumed to have an operating voltage range of +10% to

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-20% of nameplate, which can no longer be supported with documentation. The operating ranges for the various size valves have been updated, based on documentation supplied by the valve vendor; 2) A 4% reduction in the Design Calculation 835 degraded grid voltage level was previously used as the setpoint for the ,

relay. This 4% margin can not be supported and has been removed from the calculation of the degraded grid relay setpoint. The trip setpoints and allowable valve tolerances remain at 12% as currently stated in the Technical Specifications.

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, The proposed change will modify the voltage setpoint for Division 1 3

buses only. The Division I design incorporates a load tap changing ,

transformer between its offsite power supply and the Emergency Bus.

, The limiting factor voltage for Division I is the voltage required to operate equipment at lower voltage levels. The Division II design i provides a fixed ratio transformer between its offsite power supply and the Emergency Bus providing voltage regulation from the monitored

. bus to the lower voltage bus loads. Unlike Division I, Division II is limited by the voltage required to operate equipment connected to the monitored 4160 volt bus rather than the voltage required to operate lower voltage bus loads. The Division 2 degraded grid voltage and

, time delay are adequate as presently described in the Fermi Technical Specifications.

f This change in setpoint moves the level of separation of onsite Class

! IE buses from offsite power for a degrading grid condition into a more l I conservative direction by ensuring the availability of higher A.C.  ;

operating voltages. ,

b) Alarm relaying has been provided to alert the operators that i a low voltage condition exists. The relay setpoints were determined on the basis of calculations described in Section -

a) above. The setpoint of the alarm relay is above that of ,

the degraded grid trip setpoint. This was done to give the l operators advance notice of system degradation. Upon  :

receipt of the alarm and before the voltage has fallen belov ,

, the minimum voltage to preclude damage to Class IE l equipment, the plant operators, in conjunction with the

Edison System Supervisor, can take corrective action to r

prevent the grid voltage from decaying further. These l actions may include, but are not limited to, initiation of

• the offsite peaking units or offsite switching. The higher alarm setpoint eliminates any possibility of setpoint drift permitting the trip function of the degraded grid relays ,

! from being actuated ahead of an alarm. The alarm will in no i

way affect the setpoint or time delay of the degraded grid -

relaying.  ;

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c) The time delay for the actuation of the degraded grid.

undervoltage relay has been selected to be as short as possible, without encountering spurious trips from motor starts. The time delay must be long enough to prevent tripping for the worst case transient, start of two RHR and two core spray motors per division from a LOCA with the grid voltage near its lower limit. The required time delay was determined in accordance with motor start time calculations . The motor. start times plus a 10% margin  ;

pro'vided the 19.7 second delay .for Division 1 degraded grid ;

relaying. The present time delay, as depicted in our Technical Specification remains accurate, d) The Fermi Technical Specifications in Section 3/4.3.3, Emergency Core Cooling System Actuation Instrumentation, provide the limitihg conditions for operation and surveillance requirements. Table 3.3.3-2 provides the trip setpoints with minimum and maximum limits and allowable values for the degraded grid voltage sensors and their associated time delay devices.

Environmental Effect The modification of the ECCS actuation instrumentation setpoints'does -

not; 1) involve a significant. hazards consideration; 2) change the type of~or increase the amount of any effluents that may be released  :

offsite; and, 3) does not significantly increase the individual or  !

cumulative occupational radiation exposure. The requested Technical .

Specification change qualifies for a categorial exclusion in accordance with 10CFR51, part 22 (c) (9) .

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A2-l' ATTACHMENT TWO i

Sionificant Hazards Analysis As stated in 10CFR 50.92(c), a proposed amendment to an operating license involves no significant hazards consideration if ,

, operation of the facility in accordance with the proposed amendment would not:

1. Involve a significant increase in the probability or consequences of an accident previously evaluated.

- The proposed revision to Table 3.3.3-2 of Specification 3/4.3.3 would increase the 4.16 kv Emergency Bus

' Undervoltage (Degraded Voltage) (Division 1) instrument

. setpoint which would raise the point at which the class IE buses would separate from the offsite power source for a degrading grid condition. This change does not change any

- of the parameters of previous accident analysis.

Introduction of the higher instrument setpoints will increase the minimum voltage allowed on the Class IE buses for a degrading grid and thus decrease the probability or consequences of an accident previously evaluated.

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2. Create the possibility of a new or different kind of accident from any accident previous 1v evaluated.

i The new instrument setpoint supports the assumptions in the accident analysis that adequate offsite power will be

available to operate ECCS equipment or the Class IE buses will be transferred to the Emergency Diesel Generators. No 1

new accident possibilities are created by increasing the j setpoints.

3. Involve a significant reduction in a' margin of safety.

! The proposed changes do not involve a significant reduction

! in a margin of safety. The instrument surveillance i

frequency is unchanged as is the technical basis for the

surveillance requirements. The power systems ability to f satisfy the design requirements for-the offsite power source is not reduced from original plant design.

Summary Based on the technical justification and the analysis above, Detroit Edison has determined that the proposed change to the Technical Specifications does not involve any significant hazards consideration.

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A3-1 ATTACHMENT THREE TECHNICAL SPECIFICATION IMPACT ON RESTART In accordance with Technical Specification 3.3.3, the ECCS actuation instrumentation channels shown in Table 3.3.3-1 shall be operable with their trip setpoints set consistent with the values shown in Table 3.3.3-2. The values listed in Table 3.3.3-2, for item 5.b, Division I, have been determined to be invalid. Therefore, the intent of Technical Specification operability has not been met for Division I.

In accordance with Table 3.3.3-1, item 5.2, the Loss of Power (degraded voltage) function is required to be operable in Operational Condition 1, 2, 3, 4** and 5** (** required when ESF equipment is required to be operable). The plant is presently in Operational Condition 5. In accordance with Technical Specification 3.8.1.2.b the required onsite AC electrical power source is being supplied by the Division II Emergency Diesel Generators (EDGs). The Division I EDGs had previously been released for their required surveillance inspection, preventive maintenance activities and retesting in accordance with the existing outage schedule.

The intent of Table 3.3.3-1, item 5.2 is no longer met for Division I and the required action would be to declare the associated diesel generators inoperable and take the action required by Technical Specification 3.8.1.2. The action statement associated with Technical Specification 3.8.1.2 does not apply at this time because the Division II EDGs are operable.

Outage work associated with the Division I EDGs is complete and they were placed in standby on June 6, 1986. The present outage schedule requires that the Division II EDGs be released for surveillance inspection, preventive maintenance activities and subsequent retesting by June 13,~1986. Technical Specification 3.8.1.1 requires two onsite AC electrical power sources to be operable during Operational Conditions 1, 2, and 3.

It is expected that the Technical Specification amendment associated with the station batteries will be available on June 13, 1986. At that time, in accordance with our outage schedule, the Division I j station batteries will be declared operable. Subsequent to station l battery operability the Division I EDGs must be Geclared operable to preclude delays on Division II EDG work. Division I EDGs must be declared operable to avoid entering the action statement associated with Technical Specification 3.8.1.2 (i.e. no onsite AC electrical i power sources operable), upon releasing the Division II EDGs for j outage related work.

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A3+2 In summary, if the subject Technical Specification change 10 not approved by June 13, 1986 the presently scheduled Division II EDG surveillance inspections, Division Il station battery replacement, and the subsequent restart of Fermi 2 will be delayed on a day-to-day basis. Per the existing outage logic, were it not performed during this outage, the 18 month frequency for the Division II EDG surveillance inspection will require that the plant be shutdown by August 28, 1986 without utilizing any of the allowed surveillance extensions. The next anticipated outage for Fermi 2 is not until 1988.

Extension of the current outage to allow completion of the planned surveillances while pursuing the normal license amendment process would prevent the resumption of operation in a timely manner.

Prohibiting the inclusion of the 18 month Division II EDG surveillance due to failure to approve the requested change in a timely manner, will require an additional shutdown to comply with the surveillance requirements of the Technical Specifications.10CFR50.91(A) (5) allows for emergency consideration of changes for which " failure to act in a timely way would result in derating on shutdown of a nuclear power plant, or in prevention of either resumption of operation or or increase in power input up to the plant's licensed power level". The requested change clearly qualifies for processing as an emergency change.

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• ATTACHMENT FOUR Proposed Amendment Chanaes Face Affected Table 3.3.3-2, Page 3/4 3-28 See markup sheet A4-2 9

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