ML20207G000
| ML20207G000 | |
| Person / Time | |
|---|---|
| Site: | Millstone, Haddam Neck, 05000000 |
| Issue date: | 12/17/1986 |
| From: | Mroczka E CONNECTICUT YANKEE ATOMIC POWER CO., NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES |
| To: | Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| A06150, A6150, IEB-86-001, IEB-86-003, IEB-86-1, IEB-86-3, NUDOCS 8701060280 | |
| Download: ML20207G000 (8) | |
Text
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.o General Offices a Seiden Street, Berhn, Connecticut
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P.O. BOX 270
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HARTFORD, CONNECTICUT 06141-0270 L
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(203) 665-5000 December 17,1986 Docket Nos. 50-213 50-245 50-336 50-423 A06150 l
Dr. Thomas E. Murley
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Regional Administrator U.S. Nuclear Regulatory Commission l
Region !
631 Park Avenue King of Prussia, Pennsylvania 19406
Reference:
(1) 3.F. Opeka letter to T.E. Murley, " Millstone Unit No.1, IE Compliance Bulletin No. 86-01, Minimum Flow Logic Problems That Could Disable RHR Pumps," dated May 30,1986.
(2) 3.F. Opeka letter to T.E. Murley, "Haddam Neck Plant, Millstone Nuclear Power Station, Unit Nos.1, 2 and 3, IE Compliance Bulletin No. 86-03, Potential Failure of Multiple ECCS Pumps Due to Single Failure of Air-Operated Valve in Minimum Flow Recirculr. tion Line," dated November 20,1986.
Gentlemen:
Haddam Neck Plant Millstone Nuclear Power Station, Unit Nos.1,2 and 3 IE Compliance Bulletin No. 86-03 Potential Failure of Multiple ECCS Pumps Due to Single Failure of Air-operated Valve in Minimum Flow Recirculation Line IE Compliance Bulletin No. 86-03 informs licensees of single failures of minimum flow recirculation lines containing air-operated isolation valves which could result in a common-cause failure of all emergency core cooling system (ECCS) pumps in a system.
Reference (1), which was submitted in response to IE Compliance Bulletin No. 36-01 for Millstone Unit No.1, adequately addresses the concerns of IE Compliance Bulletin No. 36-03.
Due to an inadvertent oversight, Reference (2) was not notarized as required pursuant to IE Compliance Bulletin No. 36-03. Hence this submittal, as properly notarized, supersedes Reference (2). No other changes to Reference (2) have been made.
8701060280 861217 PDR ADOCK 05000213
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Haddam Neck Plant Actions Required :
1.
Promptly determine whether or not your facility has 'a single-failure vulnerability in the minimum flow recirculation line of any ECCS pumps that could cause a failure of more than one ECCS train.
Response
The charging pumps, the High Pressure Safety Injection (HPSI) pumps, and the Low Pressure Safety Injection (LPSI) pumps are e
all equipped with minimum flow recirculation lines with valves which are all locked open.
There is no failure which could cause any of these valves to shut by itself.
Adequate administrative controls exist to ensure they are not inad-vertently shut by an operator.
Hence, the Haddam Neck Plant does not have the above mentioned vulnerability.
J Modifications to the ECCS system, which are planned for the next refueling outage, will result in the installation of two series motor operated valves in the HPSI pumps common recirculation line designed to shut off flow to the refuelina water storage tank when the HPSI pumps are used for high head recirculation following a small break loss of coolant accident.
These valves will be remote manually operated, and, if open, could not close inadvertently due to any conceivable failure.
Therefore, the unit will remain free of the above mentioned vulnerability.
2'.
If the problem exists:
(a) promptly. instruct all operating shifts of the problem and measures to recognize and mitigate the problem; (b) promptly develop and implement corrective actions which bring your facility into compliance with GDC 35.
Response
Since this problem does not exist,III this is not applicable.
l (1) It should be noted that the Staff had previously forwarded to CYAPCO a temporary exemption from the single failure criterion (GDC 35) by letter dated April 28, 1986, and'that our dialogue on the subject is ongoing.
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. Northeast Utilities hereby submits the report required by action item number 3 of this Bulletin for the Haddam Neck Plant and Millstone Unit Nos. 2 and 3, as attachments. Based upon cur evaluations, we have concluded that the safety concerns outlined in Bulletin 86-03 have been adequately addressed and that these concerns are hereby not applicable to any of our nuclear units. This submittai concludes our planned actions regarding IE Bulletin No. 36-03.
We trust you find this information satisfactory.
If you have any further questions, please contact us.
Very truly yours, CONNECTICUT YANKEE ATOMIC POWER COMPANY NORTHEAST NUCLEAR ENERGY COMPANY n/
E. 3 o'chka
/
Senio ice President Attachments cc:
Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555 STATE OF CONNECTICUT )
) ss. Berlin COUNTY OF HARTFORD
)
Then personally appeared before me E. 3. Mrozcka, who being duly sworn, did state that he is Senior Vice President of Connecticut Yankee Atomic Power Company and Northeast Nuclear Energy Company, Licensees 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.
&otary Publif~:& Al?sh W~
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- 3.
Within 30 days of receipt of this Bulletin, (a) provide a written report to the NRC which identifies whether or not thin problem exists at your facility, (b) if the problem exists (or existed), include in the report the justification for continued operation and identify the short term.modifi-cations to plant operating procedures or hardware that have l
been or are being implemented to ensure safe plant i
operations.
Response
The written report is hereby submitted.
Since this problem does not exist, (b) is not applicable.
4.
If the problem exists (or existed), provide a written report within 90 days of receipt of this Bulletin informing the NRC of the schedule for long-term resolution of this and/or any other significant problems that are identified as a result of this Bulletin.
Response
Since this problem does not exist, this is not applicable.
This completer, all planned action regarding IE Compliance Bulletin 86-03.
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Millstone Unit No. 2 Actions Required:
1.
Promptly determine whether or not your facility has a single-failure vulnerability in the minimum flow recirculation line of any ECCS pumps that could cause a failure of more than one ECCS train.
Response
The High Pressure Safety Injection (HPSI) pumps and the Low i
Pressure Safety Injection (LPSI) pumps are equipped with minimum flow recirculation lines which combine intosa common return header back to the refueling water storage tank.
There are two air operated valves in the common line which fail open.
These valves will only close when a sump recirculation actuation signal is present and a keylock switch on the main control board is operated.
The charging 4
pumps, which are positive displacement pumps, are protected by relief valves on their discharge lines.
There are no other valves in these lines..Hence, Millstone Unit No. 2 does not have the above mentioned vulnerability.
2.
If the' problem exists:
(a) promptly, instruct all operating shifts of the problem and measures to recogntre and mitigate the problam; (b) promptly develop and implement corrective actions which bring your facility into complianc, with GDC 35.
Response
Since this problem does not exist, t'his is not applicable.
4 3.
Within 30 days of receipt of this Bulletin, (a) provide a written report to the NRC which identifies whether or not this problem exists at your facility, (b) if the problem exists (or existed), include in the report the justification for continued operation and identify the short term modifi-i cations to plant operating procedures or hardware that have been or are being implemented to ensure safe plant operations.
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Response
The written report is hereby submitted.
Since this problem does not exist, (b) is not applicable.
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4.
If the problem exists (or existed), provide a written report within 90 days of receipt of this Bulletin informing the NRC of the schedule for long-term resolution of this and/or any other significant problems that are identified as a result of this Bulletin.
Response
Since this problem does not exist, this is not applicable.
This completes all planned action regarding IE Compliance Bulletin 86-03.
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Millstone Unit No. 3
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Actions Reauired:
I 1.
Promptly determine whether or not your facility has*a single-failure vulnerability in the minimum flow recirculation line of any ECCS pumps that could cause a failure of more than one ECCS train.
Response
l The charging pumps, the Safety Injection Pumps, the Containment Recirculation Pumps and the Residual Heat Removal Pumps are all equipped with minimum flow recirculation lines with valves that are all motor operated.
The recirculation lines for the charging pumps isolate automatically on a safety injection signal (SIS); however, another path is made available by an automatically opened motor operated valve which is powered by the same electrical bus as the pump it protects.
A relief valve in this line provides a final means of protection for the pumps (which are individually provided with recirculation lines).
The safety injection pump recirculation lines have motor operated valves which are manually closed from the control roora during lineup for recirculation.
The Residual Heat Removal Pumps and the Containment Recirculation Pumps are equipped with individual train recirculation lines with motor operated valves which automatically operate to control pump flow.
Hence, there is no single failure which could disable both trains of any ECCS system.
2.
If the problem exists:
(a) promptly instruct all operating snifts of the problem and measures to recognize and mitigate the problem; (b) promptly develop and implement corrective actions which bring your f acility into compliance with GDC 35.
Response
Since this problem does not exist, this is not applicable.
3.
Within 30 days of receipt of this Bulletin, (a) provide a written report to the NRC which identifies whether or not this problem exists at your facility, (b) if the problem exists (or existed), include in the report the justification for continued operation and identify the short term modifi-cations to plant operating procedures or hardware that have been or are being implemented to ensure safe plant operations.
, Response:
The written report is hereby submitted.
Since this problem does not exist, (b) is not applicable.
4.
If the problem exists (or existed), provide a written report within 90 days of receipt of this Bulletin informing the NRC of the scheaule for long-term resolution of this and/or any other significant problems that are identified as a result of this Bulletin.
Response
Since this problem does not exist, this is not applicable.
This cor.pletes all planned action regarding IE Compliance Bulletin 86-03.
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