ML20249B075

Safety Evaluation Supporting Amend 216 to License DPR-65

ML20249B075
Person / Time
Site:	Millstone
Issue date:	06/16/1998
From:	NRC (Affiliation Not Assigned)
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ML20249B074	List: ML20249B073 ML20249B075
References
NUDOCS 9806220041
Download: ML20249B075 (6)

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NUCLEAR REGULATORY COMMISSION l

WASHINGTON, D.C. 20086-0001

.....l SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 216 TO FACILITY OPERATING LICENSE NO. DPR-65 NORTHEAST NUCLEAR ENERGY COMPANY THE CONNECTICUT LIGHT AND POWER COMPANY l

THE WESTERN MASSACHUSETTS ELECTRIC COMPAf4Y MILLSTONE NUCLEAR POWER STATION. UNIT NO. 2 DOCKET NO. 50-336

1.0 INTRODUCTION

By letter dated December 8,1997, the Northeast Nuclear Energy Company, et al. (the licensee),

submitted a request for changes to the Millstone Nuclear Power Station, Unit No. 2 Technical Specifications (TSs). The requested changes would modify the TSs to resolve several compliance issues by rewording of the text, changing terminology, correcting a mode

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applicability, correcting a formula, updating the Design Features section, and updating the Bases section to reflect the changes.

Specifically, the licensee proposes to: (1) correct the wording and the formula in TS Definition 1.18 " Azimuthal Power Tilt - T,"; (2) correct the wording in TS 4.1.1.1.2 " Reactivity Control Systems-Shutdown Margin - T, > 200"F"; (3) correct the mode applicability from Mode 3 to Modes 1 and 2 in TS 3.1.3.4 " Reactivity Control Systems - CEA [ Control Element Assembly) Rod Drop Time"; (4) correct the terminology used to refer to the power dependent insertion limit alarm in TS 4.1.3.6 " Reactivity Control Systems - Regulating CEA Insertion Limits"; (5) add a footnote for Mode 4 operability requirement clarification to TS 3.5.3 "ECCS [ Emergency Core Cooling Systems) Subsystems - T, < 300*F"; (6) correct the wording, frequency, and reference number l

for the surveillance requirements in TS 3.6.3.2 and TS 4.6.1.7 " Containment Systems -

Containment Ventilation System"; (7) correct the nomenclature used for the A.C. busses in TSs 3.8.2.1,3.8.2.1 A, and 4.8.2.1 A "Onsite Power Distribution Systems - A.C. Distribution -

Operating"; (8) correct TS Bases by modifying the applicable sections to reflect the proposed changes; (9) delete the word " original" from the statement " original design provision" in Design Features Section - TSs 5.1.3 " Flood Control," 5.2.3 " Penetrations," 5.3.2 " Control Element Assemblies," and 5.7.1 " Seismic Classification"; and (10) delete Design Features Section - TS 5.9 " Shoreline Protection."

2.0 EVALUATION i

Request No.1: Correct the wording and the formula in TS Definition 1.18 " Azimuthal Power Tilt - T,. "

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1., = An error in the Azimuthal Power Tilt (T,) definition and formula was discovered by the licensee during the implementation of its Configuration Management Program. T,is calculated to verify.

compliance with TS 3.2.4 and is associated with the quadrant of highest power production with respect to the average of the four quadrants instead of the quadrant that deviates the most from the average of the four quadrants. This issue has also been addressed by Asea Brown Bover-Combustion Engineering (ABB-CE) Infobulletin, No. 97-07 " Tech Spec on Azimuthal Tilt in Analog Plants," dated October 28,1997.

TS Definition 1.18 currently states, in part, "...the maximum difference between the power generated in any core quadrant...," which the licensee proposes to change to, "...the difference between the maximum power generated in any core quadrant." The December 8,1997, submittal provided an example of how the current wording could lead to an incorrect interpretation and result in achieving the wrong answers when calculating the T,. The proposed wording eliminates the possibility of a misinterpretation occurring.

The Core Power Distribution Monitoring System utilizes the INPAX algorithm, which is a computer program developed by Siemens Power Corporation, which supplies the fuel for the Millstone, Unit 2, reactor. The ABB-CE information bulletin is applicable to CE analog plants that use the INCA /CECOR/COLSS algorithms and is not applicable to Millstone, Unit 2.

The proposed corrections to the formula delete

• max" from outside the brackets.and add

" maximum"inside the brackets. In addition, the symbols currently used to represent the brackets would be replaced because they could be incorrectly interpreted as absolute signs. The corrections to the formula makes it consistent with the existing method for calculating power

. distribution factors utilizing the INPAX algorithm and how they are applied in the design basis

~ accident analysis. Thus, the proposed changes to the wording and formula in TS Definition 1.18 are acceptable and will provide reasonable assurance that the T, will be correctly calculated.

Request No. 2: Correct the wording in TS 4.1.1.1.2, " Reactivity Control Systems - Shutdown Margin - T > 200'F."

TS 4.1.1.1.2 surveillance requires that the difference between predicted and measured core reactivity values be maintained within plus or minus 1.0 percent delta k/k, and that an adjustment be made between the measured and predicted core reactivity conditions prior to exceeding 60 effective full power days following a refueling outage. The proposed change is to replace the statement, "The predicted reactivity values shall be adjusted.;." with "The predicted reactivity

. values may be adjusted."

Historically, this difference has been small at Millstone, Unit 2, and an adjustment has not been necessary to ensure the plus or minus 1.0 percent delta k/k limit is maintained. The fact that no adjustment (normalization) will be required when reactivity differences are within the required l

limits will not affect the ability to identify reactivity anomalies. In the past, the licensee has not

, made a4ustments when the measured and predicted values were within the plus or minus I

1.0 percent delta k/k lirnii" This resulted in being in noncompliance with the requirements of l

L TS 4.1.1.1.2 as reported in Licensee Event Report (LER) 97-022-01, " Technical Specification Violations," dated June 6,1997.

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The licensee indicated in the corrective action portion of the LER that it would propose changes to the TS surveillance to assure that the required limits are being met. The proposed change is l

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.5b' 3-also consistent with the guidance provided in NUREG-1432, Rev.1, " Standard Technical

. Specifications Combustion Engineering Plants," dated April 1995. Thus, the proposed change to

- TS 4.1.1.1.2 provides resonable assurance that the plus or minus 1.0 percent data K/K limit will be maintained; therefore, it is acceptable.

Request No. 3: Correct the mode applicability from Mode 3 to Modes 1 and 2 in TS 3.1.3.4

" Reactivity Control Systems - CEA Rod Drop Time, " and add a symbol to the supporting TS Bases 3/4.1.3.

. Control Element Assembly drop time is important for the mitigation of accidents that are initiated while the reactor is critical. It is necessary to verify CEA drop time with plant conditions consistent with those expected when the reactor is critical to ensure the CEA drop time assumed -

in the design basis accident analysis is valid. TS 3.0.4, " Limiting Conditions for Operation," and TS 4.0.4, " Surveillance Requirements," require that the limiting conditions for operation (LCOs) and associated surveillance be met prior to the TS becoming applicable.

LTS 3.1.3.4 LCOs, T, equal to or greater than 515'F, and four reactor pumps in operation cannot be established prior to entry into Mode 3. These conditions are necessary to perform the TS 4.1.3.4 CEA drop time surveillance. The current Mode 3 applicability of TS 3.1.3.4 has resulted in nonconformance with TSs 3.0.4 and 4.0.4 during plant startup as reported in LER 97-022-02, " Technical Specification Violations," dated November 26,1997.

The proposed change to TS 3.1.3.4 will change the applicability from Mode 3 to Modes 1 and 2.

This is necessary to allow the surveillance requirements of TS 4.1.3.4 to be performed at the conditions assumed in the design basis accident analysis and also as specified in the LCO..The

- proposed change will allow this verification, and thereby ensure the CEAs will function as designed to mitigate design basis accidents. Thus, the NRC staff has determined that the proposed change to TS 3.1.3.4 to make it applicable in Modes 1 and 2 is acceptable including the addition of an equal to or greater than symbol before 515'F in the supporting TS Bases, 3/4.1.3, to be consistent with the current LCO.

Request No. 4: Correct the terminology used to refer to the power dependent insertion limit alarm in TS 4.1.3.6, " Reactivity Control Systems - Regulating CEA insertion Limits." and update

' the supporting TS Bases Section 3/4.1.3.

The proposed change to the TS 4.1.3.6 surveillance requirement will change the power dependent insertion limit (PDIL) from "PDIL Auctioneer Alarm Circuit" to "PDIL alarm." This change only modifies the terminology used to refer to the PDfL alarm to agree with plant terminology to avoid any confusion because alarm circuits do not have specific names. The licensee notes that the alarm function is provided by the Control Element Assembly Position Display System (CEAPDS) computer and is referred to as the PDIL alarm. TS Bases 3/4.1.3 will be changed to indicate that the CEAPDS computer provides the PDIL alarm. Thus, the NRC staff has determined that the proposed change to TS 4.1.3.6 and TS Bases 3/4.1.3 are acceptable.-

Request No. 5: Add a footnote for Mode 4 operability requirement clarification to TS 3.5.3

- ECCS Subsystems - T, < 300 'F ". and supporting TS Bases 3/4.5.3.

TS 3.5.3 currently requires an operable flow path capable of taking a suction from the refueling

' water storage tank (RWST) on a safety injection actuation signal (SIAS), and automatically transfening suction to the containment sump on a sump recirculation actuation signal (SRAS) in

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CL Mode 4. However, when in Mode 4, the automatic SlAS generated by low pressurizer pressure.

and high containment pressure and the automatic SRAS generated by low RWST level are not required to be operable according to TS 3.3.2.1, Table 3.3-3. Automatic' actuation in Mode 4 is not required because adequate time is available for plant operators to evaluate plant conditions,

and respond by manually operating engineered safety features components.

The licensee proposes that credit be given for remote manual operation to generate the SIAS and SRAS, which will position all components to the required accident position, because the manual actuation (trip pushbuttons) portions of the SIAS and SRAS are required to be operable in Mode 4.

The proposed change to TS 3.5.3 will add a footnote to explain that the operability requirement for the SIAS and SRAS are met by use of the safety injection and sump recirculation trip pushbuttons while in Mode 4. In addition, TS Bases 3/4.5.3 will be updated to reflect the proposed change.. This change will not reduce operability or surveillance requirements for the ECCS subsystems required to be operable by TS 3.5.3. The ECCS will continue to function as

. designed to mitigate design basis accidents. The proposed change is also consistent with the guidance provided in NUREG-1432, Rev.1, " Standard Technical Specifications Combustion Engineering Plants," dated April 1995. Thus, the NRC staff has determined that the addition of the footnote to TS 3.5.3 and updating TS Bases 3/4.5.3 are acceptable.

i Request No. 6: Correct the wording for the requirements in TS 3.6.3.2 " Containment Systems -

Containment Ventilation System," and the frequency and reference number in TS 4.6.1.7 surveillance requirement.

The proposed change to TS 3.6.3.2 and TS 4.6.1.7 will revise the wording of the LCO, action statement, and surveillance requirement by changing " locked closed" to " sealed closed," and deleting the requirement to be " electrically deactivated" for the containment purge supply and exhaust isolation valves. The valves cannot be locked closed because the valves do not have manual operating devices. This requirement is met by removing the control power fuses for each of the valves and locking the access to the associated fuse blocks. Removal of the control power fuses will not allow air pressure to be available to provide an opening force against the springs, which hold the valves closed. The use of " sealed" closed is appropriate in that it is a.

more accurate description of the requirement. Deleting the reference to " electrically deactivated" from the TS is also appropriate in that it is descriptive of the method used to meet the requirement to seal the valves closed and should be included in the TS Bases, as proposed by the licensee. These changes will not affect the requirement fpr the containment purge valves to be closed in Modes 1 through 4.-

In addition, the proposed change to the TS 4.6.1.7_ surveillance requirement will change the surveillance frequency from " prior to each reactor startup" to."at least once per 31 days " This change will ensure consistency between the surveillance and the applicability portions of this specification. The applicability of TS 3.6.3.2 is Modes 1 through 4 and the current req'uirement

could be interpreted to be Mode 2. Also, the change will require that the surveiiiance De i

. performed more often, providing additional assurance that the containment purge valves are '

sealed closed, and the change is consistent with the current surveillance requirements of -

._TS 3.6.1.1,." Containment Requirements." The change in numbering of TS 4.6.1.7 to TS 4.6.3.2,

' to be consistent with TS 3.6.3.2, is an administrative change ano will not affect any technical aspect of the TS requirements. The proposed changes are also consistent with the guidance

provided in NUREG-1432, Rev.1, " Standard Technical Specifications Combustion Engineering.

Plants," dated April 1995. Thus, the NRC staff has determined that the proposed changes to TS 3.6.3.2, TS 4.6.1.7, and TS Bases 3/4.6.3 are acceptable.

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' Request No. 7: Correct the nomenclature used for the A.C. busses in TSs 3.8.2.1, 3.8.2.1 A, and.

4.8.2.1A "Onsite Power Distnbution Systems - A.C. Distribution - Operating."

The proposed changes to TS 3.8.2.1, TS 3.8.2.1 A, and TS 4.8.2.1A will modify the nomenclature used to refer to the vital A.C. busses to be consistent with the terminology used by Millstone,

. Unit 2, Operations Department personnel and as contained in the procedures they use. These

. changes will not alter equipment operation or any technical kspects of these specifications. The A.C. busses will continue to function as designed to mitigate design basis accidents. Thus, the NRC staff has determined that the proposed changes to TS 3.8.2.1, TS 3.8.2.1 A, and TS 4.8.2.1 A are acceptable.

Request No. 8: Correct the TS Bases by modifying the applicable sections to reflect the proposed changes.

' The NRC staff has determined that, as noted with each of the requested TS changes previously discussed, updating the applicable portion of the TS Beses is acceptable.

~ Request No. 9: Delete the word " original" from the statement " original design provision" in Design Features section - TSs 5.1.3 " Flood Control," 5.2.3 " Penetrations," 5.3.2 " Control Element Assemblies," and 5.7.1 " Seismic Classification."

The proposed changes to TSs 5.1.3, 5.2.3, 5.3.2, and 5.7.1 will remove the word " original."

Reference to " original" design is not appropriate because these items can be changed by approved processes. However, these changes will still require the design provisions addressed by these TSs to be designed and maintained in accordance with the Final Safety Analysis Report. The proposed changes have no effect on the current approved plant design. Thus, the NRC staff has determined that deleting the reference to the " original" design provisions from TS 5.1.3, TS 5.2.3, TS 5.3.2, and TS 5.7.1 is acceptable.

Request No.10: Delete Design Features section - TS 5.9 " Shoreline Protection."

The required provisions for shoreline protection were completed by the June 15,1976, date specified in TS 5.9. There are no specific design features identified in the TS and it is no longer necessary. The removal of this outdated specification, which only specified a completion date and no design description or details, will not impact any current requirements relating to shoreline protection described in the FSAR for Millstone, Unit 2. Thus, the NRC staff has determined that, based on the preceding discussion, deleting TS 5.9 is acceptpble.

3.0 -

STATE CONSULTATION in accordance with the Commission's regulations, the Connecticut State official was notified of the proposed issuance of the amendment. The State official had no comments.

4.0 ;

ENVIRONMENTAL CONSIDERATION The amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes surveillance requirements.; The NRC staff has determined that the amendment involves no significant 7

increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the L

amendment involves no significant hazards consideration, and there has been no public

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6-comment on such finding (63 FR 4319 dated January 28,1998), ' Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to :

.10 CFR 51.22(b) no environmentalimpact statement or environmental assessment need be prepared in connection with the issuance of the amendment.

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CONCLUSION The Commission has concluded,' based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

Principal Contributor: Daniel Mcdonald Date:

June 16, 1998 i

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