ML19324C340
| ML19324C340 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 11/02/1989 |
| From: | Mroczka E, Werner R NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML19324C341 | List: |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, RTR-REGGD-01.097, RTR-REGGD-1.097 B13391, GL-83-37, NUDOCS 8911160150 | |
| Download: ML19324C340 (5) | |
Text
-_
o t
c j
'NM u
oenerat ottices. seinen street, eernn, Conn.ciicui 9
3 0.l.~C.Z7*I$~.~J p.o cox pro l
<L LO~C'.'. "O_
penTho,R,,, CONNECTICUT o6141-o270 j
J
%...~.
I November 2, 1989 f
Docket No. 50 423 i
B13391 l
Re:
100FR50.90 U.S. Nuclear Regulatory Commission i
Attention: Document Control Desk i
Washington, DC 20555 Gentlemen:
l l
Millstone Nuclear Power Station, Unit No. 3 Proposed Revision to Technical Specifications Containment Hydroaen Monitors i
t I
Pursuant to 10CFR50.90, Northeast Nuclear Energy Company (NNECO) hereby proposes to amend its operating license, NPF 49, by incorporating the changes identified in Attachment 1 into the Technical Specifications of Millstone Unit No. 3.
t Description of the ProDosed Chances f
Technical Specification Section 3.6.4.1 (Hydrogen Monitors) is based on and consistent with the NRC guidance included in Generic letter 83 37, NUREG-0737 Technical Specifications. The accident monitoring instrumentation included in Technical Specification Section 3.3.3.6 (Table 3.310) are those instruments provided to monitor key variables, designated as Category 1 instruments i
J following the guidance for classification contained in Regulatory Guide 1.97, Revision 2.
The hydrogen monitor is one of the parameters listed in Table
}
3.3-10.
These two different NRC guidance documents have resulted in an inconsistency in required actions if either one or both hydrogen monitors become inoperable.
This inconsistency in ACTION Statements was discovered recently when Hillstone Unit No. 3 Gntered the ACTION statements of Technical Specifications 3.6.4.1 and 3.3.3.6 for one inoperable hydrogen monitor.
The proposed changes to Sections 3.3.3.6, and 3.6.4.1 are being made to eliminate the inconsistency between the sections and avoid any unnecessary shutdown should one hydrogen monitor become inoperable.
In order to eliminate e
this inconsistency in required actions, exception is being taken for the containment hydrogen monitor in Technical Specification 3.3.3.6.a and b and an additional action statement 3.3.3.6.d is added, which addresses operability requirements for containment hydrogen monitors.
This additional action statement is consistent with the requirements of Technical Specification Section 3.6.4.1.
Mi 8911160150 891102 PDR ADOCK 05o00423 8 \\
P PDC 1
E U.S. Nuclear Regulatory Commission B13391/Page 2 November 2, 1989 Currently, Section 3.6.4.1 provides a 30 day restoration time for an inoper-able hydrogen monitor, whereas Section 3.3.3.6 provides a 7 day restoration period.
The 30-day restoration interval in Section 3.6.4.1 is consistent with the guidanc.- provided in Generic Letter 83 37 for Technical Specifications as a result of NUREG 0737.
Plant shutdown is more clearly warranted if the inoperat,16 monitor cannot be restored after 30 days rather than the 7 day limit as provided in Section 3.3.3.6, In addition, the limiting condition for operation (LCO) for two inoperable monitors is being extended from 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to ensure consistency in the Technical Specifications.
Surveillance requirements of both Sections 4.3.3.6 and 4.6.4.1 are currently being per-formed.
Since the provisions of Specification 3.0.4 are not applicable to the contain-ment hydrogen monitor as indicated in Section 3.3.3.6, those provisions should not apply to Section 3.6.4.1, therefore, specific exception to Specification 3.0.4 is being added to Section 3.6.4.1.
In addition, the applicability to Mode 3 is being added to Section 3.6.4.1 as well as the requirement to be in hot shutdown should the inoperable monitor not be restored to an operable condition within 30 days.
These requirements are being incorporated to ensure consistency between Sections 3.3.3.6 and 3.6.4.1.
Discussion The operability of the combustible gas control equipment and systems regtn m.
for the detection and control of hydrogen gas ensures that this equipment a ll be available to maintain the hydrogen concentration within containment below its flammable limit during post-loss of-coolant-accident (LOCA) conditions.
Since the hydrogen monitors provide information used to determine the need to start the hydrogen recombiners or initiate containment purge, extending the LCOs for an inoperable monitor from 7 days to 30 days and for two inoperable monitors from 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> was evaluated to determine the effects on l
the consequences of a LOCA.
In accordance with the Millstone Unit No. 3 safety analysis, the starting of ye hydrogen recom5iner as late as 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> following a design basis accident is sufficient to maintain the containment hydrogen concentration below 4 volume percent, if indication is not avail-abl e, the emergency response organization has adequate time to assess the l
situation and start a hydrogen recombiner.
In addition, other air sampling I
systems are available such as the QA Category 1 containment atmosphere radiation monitor which is used to obtain a weekly gaseous sample and the nonsafety-related post accident sampling system (PASS).
The 24-hour period l
provides adequate time to ensure that the hydrogen recombiner will be started.
l Consequences of the LOCA will not be increased by extending these LCOs.
1 1
(1) See the Millstone Unit No. 3 Final Safety Analysis Report Section 6.2.5.3, Page 6.2-74.
1
o U.S. Nuclear Regulatory Commission 813391/Page 3 November 2, 1989 Adding the provision that Specification 3.0.4 is not applicable does not impact the consequences of any accidents previously evaluated. This provision allows the plant to change operational modes, however the 30 day LCO remains valid and ensures that the added risk is sufficiently small.
Specification 3.3.3.6 contains this provision and it is being added to Specification 3.6.4.1 for consistency. Also, the applicability to mode 3 and a requirement to be in Hot Shutdown are being addeo to Specification 3.6,441 for consistency.
These additions do not impact the consequences of any accidents previously evalu-ated.
11g ificant Hazards Consideration NNECO has reviewed the proposed changes fu A cordance with 100FR50.92 and has concluded that the changes do not invoh e a significant hazards consideration.
The basis for this conclusion is that the three criteria of 10CFR50.92(c) are not compromised.
The proposed changes do r.ot involve a significant hazards consideration because the changes would not:
1.
Involve a significant increase in the probability or consequences of an accident previously analyzed.
The proposed changes to extend the LCOs for an inoperable hydrogen monitor from 7 days to 30 days and for two inoperable monitors from 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> do not increase the conse-quences of a design basis accident (DBA) LOCA for the following reason.
Initiation of one hydrogen recombiner as late as 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> following a DBA is sufficient to maintain the containment hydrogen concentration below 4 volume percent.
In addition, other air sampling systems would be avail-able to determine the concentration.
Since adequate time exists for the operator to assess the situation, obtain alternative samples and initiate t
the hydrogen recombiners, the consequences of LOCAs will not be j
increased.
Adding the provision that Specification 3.0.4 is not applicable allows the plant to change operational modes without the hydrogen monitors I
However, since the LCOs remain valid, the added risk is negligibly small and therefore does not significantly increase the consequences of an accident.
Also, mode 3 applicability and a require-ment to be in hot shutdown have been added for consistency and do not I
impact the consequences of an accident.
2.
Create the possibility of a new or different kind of accident from any previously analyzed accident. There are no failure modes associated with l
these changes.
Since there are no changes in the way the plant is operated or in the operation of the equipment credited in the DBA, the potential for an unanalyzed accident is not created.
l 3.
Involve a significant reduction in the margin of safety.
The intent of the Technical Specification is to ensure that the operator will be able to determine the hydrogen concentration and start the recombiner or containment purge before reaching 4 volume percent.
Since the operator
)
j l
U.S. Nuclear Regulatory Commission r
B13391/Page 4 November 2, 1989 1
has at least 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> before a recombiner must be initiated and other i
sampling systems will be available, the intent of the Technical Specifi-cation is met.
For this reason, the changes will not impact any protec-tive boundary.
The changes do not affect the consecuences of any acci-i dent previously analyzed.
Therefore, there is no c< gnificant reduction in the margin of safety.
l In summary, for the reasons identified above, NNECO has concluded that contin-ued operation of the facility in accordance with the proposed amendment would l
not involve a significant hazards consideration.
i Moreover, the Commission has provided guidance concerning the application of standards in 10CfR50.92 by providing certain examples (March 6,
- 1986, SIFR7751) of amendments that are considered not likely to involve a signifi-cant hazards consideration.
Although the proposed changes are not enveloped by a specific example, the proposed changes would not involve a significant increase in the probability or consequences of an accident previously ana-lyzed.
Since adequate time exists for the operator to assess the situation, obtain alternative samples, and start a hydrogen recombiner and/or containment purge, the consequence of LOCAs will not be increased.
It should also be noted that the subject amendment request conforms to the guidance provided by the Staff via Generic letter 83-37.
l u
Conclusion t
Based upon the information contained in this submittal and the environmental i
assessment for Millstone Unit No. 3, there are no significant radiological or nonradiological impacts associated with the proposed action and the proposed license amendment will not have a significant effect on the quality of the human environment.
i i
The Millstone Unit No. 3. Nuclear Review Board has reviewed and approved this proposed amendment and concurs with the above determination.
In accordance with 10CFR50.91(b), we are providing the State of Connecticut with a copy of this proposed amendment.
Regarding our proposed schedule for this amendment, we request issuance at your earliest convenience with the amendment effective within 30 days upon issuance.
l
F c
i U.S. Nuclear Regulatory Commission B13391/Page 5 i
November 2, 1989
}
s should the Staff have any additional questions, please contact my Staff
- directly, i
Very truly yours, f
l 3
NORTHEAST NUCLEAR ENERGY COMPANY
'P -()
)l Ao %pc es E.J.Mrptyka O
Senior Vice President M
w
'By:
R. P. Werner Vice President i
cc:
W. T. Russell, Region I Administrator D. H. Jaffe,.NRC Project Manager, Millstone Unit No. 3
[
W. J. Raymond, Senior Resident Inspector, Millstone Unit Nos. 1, 2, and 3 Mr. Kevin McCarthy, Director Radiation Control Unit L
Department of Environmental Protection Hartford, Connecticut 06116
~
STATE OF CONNECTICUT ss. Berlin COUNTY OF HARTFORD Then personally appeared before me, R. P. Werner, who being duly sworn, did l
state that he is Vice President of Northeast Nuclear Energy Company, a Licensee herein, that he is authorized to execute and file the foregoing information in the name and on behalf of the Licensees herein, and that the statements contained in said information are true and correct to the best of his knowledge and belief.
%_ % AA l
Notaky Public 1'
1 l.l'