ML20006D593
| ML20006D593 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 02/06/1990 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20006D588 | List: |
| References | |
| NUDOCS 9002140086 | |
| Download: ML20006D593 (4) | |
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Y UNITED STATES NUCLEAR REGULATORY COMMISSION 3.,,
WASHINGTON D. C,20666 i...+
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT N0. 150 T0 FACILITY OPERATING LICENSE NO. DPR-66 e
DUQUESNE LIGHT COMPANY OHIO EDISON CurWANY PENNTYDIANTA"TEl"TWANY BEAVER VALLEY POWER STATION, UNIT NO.-1 DOCKET NO. 50-334 L
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1.0 INTRODUCTION
o By letter dated October as agent for the above utilities 16,1989} Duquesne Light Company (the licensee, actin proposed an amendment to Facility Operating-License No. DPR-66. The proposed amendment furnished information which clarified the. reactor coolant system (RCS) boron dilution requirements. The proposal I
included information concerning requirements for isolated loop startup and operation, as well as verification of the available shutdown margin-(as noted l
in revisions to the surveillance requirements). We have completed our review of.the proposed amendment request, noting that the changes-follow existing--
specifications in the D.C. Cook and Millstone 3 Technical Specifications.
2.0 DISCUSSION AND EVALUATION g
2.1 -Specification 3.1.1.3 - Boron Dilution The licensee proposed to revise this specification by adding a footnote
- l applicable to the word " reduction." This note clarifies the meaning of boron reduction, such that, for purposes of this specification, water added to the RCS will not constitute a reduction in boron concentration as long as the boron l-concentration of the water being added is greater than the minimum boron concentration that would satisfy the specified mode-dependent minimum shutdown requirement.
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The clarification of boron reduction will reduce the delays encountered during l
residual heat removal system (RHR) testing, RHR startup and in returning an L
isolated loop to service. Using the proposed clarification, RCS boron-L concentration reduction (or boron dilution) occurs only if the boron
. concentration of water added to the RCS is less than that concentration needed-L
-to satisfy the minimum shutdown margin requirements for a specific moda of operation. Applicable specifications are referenced to provide the mo e -dependent L
l-shutdown margin requirements. We find this clarification consistent with our l
position, and that adequate shutdown margin will continue to be maintainted.
.The footnote
- is therefore acceptable.
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The licensee also proposed to add a footnote # to the applicability statement to apply the requirements of.this specification only when fuel is in the vessel, because boron dilution is not a concern when there is no fuel in the vessel. This is a reasonable clarification of an existing specification and is acceptable.
2.2 Specification 3.4.1.3 - Reactor Coolant System Shutdown The licensee proposed to revise this specification by adding a note to define the word " dilution." This revision is similar to the note applied to the word
" reduction" in Specification 3.1.1.3.
We find this clarification to be consistent-with our position, and that adequate shutdown margin will continue to be maintained.
It is therefore acceptable.
2.3 Specification 3.4.1.4 - Isolated Loop This entire specification has been revised to address minimum shutdown requirements for an isolated loop. The new LCO requires removal of power from the associated valve operators to ensure the valves cannot be inadvertently opened to cause a
. boron dilution event.- The removal of power from the associated loop isolation valve operators is a requirement which provides an effective means of ensuring that the boron concentration in the reactor will not be subjected to dilution by mixing with potentially low-concentration borated water from an isolated loop. We consider this to be a satisfactory compensatory measure in lieu of verifying boron concentration once per-24 hours for the isolated loop as required by the previous specification.
To allow startup of an isolated loop, a footnote has been added to the LCO.
which allows power to be restored to the isolated loop stop valve operators if the new surveillance requirement 4.4.1.5.3 (below) has been satisfied. This surveillance requirement calls for verification of the isolated loop boron concentration within 30 minutes of the time the hot leg stop valves are to be l
opened and again within 30 minutes of the time the cold leg stop valves are to be opened..This footnote ensures that the minimum shutdown margin requirements have-been met. These changes will eliminate the need for periodic isolated loop boron concentration sampling and reduce the occupational doses associated with l
sampling and counting. The Action Statement has been written for consistency i
with the LC0 to require removal of power from the isolated valve operators if an operator finds power had been inadvertently restored.
A change to the applicability statement has been made to apply this specification when a loop has been isolated in modes 5 and 6 only. This change places additional limitations on N-1 loop operation, which will allow loop startup only in modes 5 and 6.
(The unit is prohibited from operation with less than three loops.
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-l SeeLicenseCondition2.C.(3)).TheSurveillanceRequirementhasbeenwritten for consistency with the LC0 to verify that at least once per 7 days power is removed from the isolated loop stop valves.
We conclude that these measures provide adequate assurance that the minimum shutdown requirements will be maintained during isolated loop operation and are therefore acceptable.
2.4 Specification 3.4.1.5 - Reactor Coolant S.ystem Cold Leo Stop Valves This specification has been revised to address the isolated loop cold leg stop valves. A new item c. is added to require the isolated loop cold leg stop
-valves be maintained closed until the isolated loop boron concentration is greater than or equal to the minimum requirements for a specific mode of operation.(Theprerequisites(itemsa,bandc)tobesatisfiedpriorto returning an isolated loop to service ensure that the isolated loop is homo-geneous with respect to boron concentration and temperature; provide adequate shutdown margin requirements for the operating RCS consistent with the shutdown margin requirements for Mode 5 (specification 3.1.1.2); provide adequate shutdown margin requirements for the isolated loop consistent with the shutdown margin for Mode 5 (specification 3.1.1.2).
The isolated loop shutdown margin requirements are equivalent to the operating loop requirements hence startup of an isolated locp in accordance with the proposed specification ensu,res that a reactivity transient will not occur. The new item c. therefore further enhances plant safety and is thus acceptable.
The applicability statement has been changed to apply the requirements of this specification during startup of an isolated loop during shutdown conditions l
(Modes 5 and 6). This is consistent with our safety evaluation on N-1 loop
, operation for Beaver Valley, Unit 1 (letter, S.A. Varga to the licensee, dated July 20 1984), which requires the plant to be shutdown to return an isolated loop-to service. This change is therefore acceptable.
Surveillance requirement 4.4.1.5.3 has been added to require verification I
of LC0 item c. 1solated loop boron concentration within 30 minutes before the l
hot leg stop valve may be opened, and again within 30 minutes before the cold l-leg stop valve is opened. This surveillance requirement has been added to ensure that the 15 shutdown margin is maintained in accordance with FSAR accident analyses, and is therefore acceptable.
2.5 Specification 3.9.8.1 and 4.9.8.1-Residual Heat Removal and Coolant circulation These specifications have been revised by adding a note a to the word " reduction".
This revision is similar to the note applied to the word " reduction" in Specifi-cation'3.1.1.3. We find this clarification to be consistent with our position that adequate shutdown margin be maintained (see discussion in Section 2.1).
The changes are therefore acceptable.
A footnote # has been added to " Mode 6". It specifies that the Action items 3
are applicable only when there is fuel in the reactor vessel. This change is consistent with operating requirements and we therefore find this footnote acceptable.
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t; 2.6 Specification Bases 3/4.4.1 - Reactor Coolant Loons 1
The licensee has revised the associated bases to reflect the above chances.
1 We found the revised bases acceptable as discussed in Sections 2.1 through 2.5.
I 3.0 ENVIR0t31 ENTAL CONSIDERATION This amendment changes requirements with respect to the installation or use
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of facility componentslocated within the restricted area as defined in 10 CFR Part 20 and changes surveillance requirements. We have determined that the amendment involves no significant increase in the amounts, and no signifi-cent 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. We have previously issued a proposed finding that this amendment involves no significant hazards considerat1on and there has been no public comment on such finding. Accordingly, this 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 environmental impact statement or environmental assessment need be prepared in connection with the issuance of this amendment.
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4.0 CONCLUSION
We have concluded based on the considerations discussed above, that: (1) thereisreasonableassurancethatthehealthandsafetyofthepublic l
will not be endangered by operation in the proposed manner, and (2) such activities will be conducted in compliance with the Comission's regulations, and (3) the issuance of this amendment will not be inimical to the j
common defense and security or to the health and safety of the public.
Principal Contributor: Antoinette Massey Dated: February 6, 1990 i
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