ML19338F399
| ML19338F399 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 10/02/1980 |
| From: | Stello V NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| To: | COMMONWEALTH EDISON CO. |
| Shared Package | |
| ML19338F398 | List: |
| References | |
| IEB-80-17, NUDOCS 8010200297 | |
| Download: ML19338F399 (7) | |
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UNITED STATES.0F AMERICA
' NUCLEAR REGULATORY COMMISSION In the' Matter of
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Docket No.:
50-249
)
' Commonwealth Edison. Company
' ).'
. (Dresden Nuclear-Power Station
)
Unit No.,3)-
)
CONFI'RMATORY ORDER l:
I Commonwealth Edison Company-(the " licensee") is the holder of' Facility Operating License No. DPR-25 (the " license") with an expiration date_of October 14, 2006 which authorizes operation of the Dresden Nuclear Power Station Unit No. 3 (the l-
" facility").
l' II l
l On June 28,'1980, during a routine shutdown of the Browns Ferry Nuclear Power L
- Station' Unit 3 reactor, a manual scram from approximately'35% power failed to insert all of.the control' rods.
Three scrams were initiated over a period of p
about 14 minutes to achieve full insertion of all of the control rods.
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- The cont'rol rods ~which failed to insert were all located on the east side of the reactor. core.
Investigation indicated that this was caused by water unknowingly accumulating'in tiie east side-scram. discharge volume'(SDV).
This accumulation
- reduced the'available free volume.for' scram water discharge ~and inhibited control
-rod insertion..It is believed that an obstructed vent and/or drain caused the i
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2-accumulation' of water.
This accumulation of water was.not' detected by the reactor protection system,because.it_ stayed _within the SDV headers and did not' drain to the scram discharge instrumented v'olume (SDIV).
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On July 2, 1980,~a team of NRC Headquarters representatives went.to'the Browns Ferry site lto gather detailed information on the event and its related ~considera-
. tions.
IE Bulletin No. 80-17, " Failure of'76 of 185 Control Rods to Fully Insert During a Scram at a BWR" was issued on July 3, 1980 and requested actions ~to be taken by all' licensees of operating General Electric designed Boiling Water Reactors.
dmong the actions requested were the following:
' " 1.
Within 3 days from the date of this Bulletin, perform surveillance i
tests to verify that there is no significant amount of water in the l'
(
Scram Discharge Volume'(SDV) and associated piping and that the SDV i
l vent valves are operable and vent system is free of obstruction."
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"3.. At the. conclusion of the scram tests and all other scrams, verify that all vent lines'in the SDV are functional.
Verify that there
'is no.significant~ amount of water in the SDV and associated piping "
l "5.' : Review and develop' surveillance procedures such that scram discharge i
~. volume'is monitored daily for residue water for 6 days and, if results are acceptable,- the interval-may be' extended to 7. days."
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Additional actions applicable'to these BWR facilities were requested in
~ Supplement Nos.'1, 2, and 3 to IE Bulletin 80-17; these supplements were issued on July 18, July 22:and August 22, 1980, respectively.
Specific actions were requested with regard to the unobstructed venting _and draining of the SDV.
In particular, Item B.1 of Supplement 1: requested the following:
"B.
Actions to be Taken by BWR Licensees and Completed by September 1,
~
1980:
1)- -Install a system to continuously monitor water levels in all scram discharge volumes.
Continuous recording and alarm features' must be included in the design.
Consideration should be given to use of diverse level sensors in this (these) system (s).
The design. installed should represent ~ the design with the highest
. level of reliability compatible with completion of installation by September 1, 1980.
Provide a written description of the system design to'the NRC Regional Office.
If installation by September ~1, 1980.is not~possible, by August 15, 1980, submit:to the.NRC Regional' Office:
1)
(Documentation in detail why the installation cannot be completed' by September.1, 1980.
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A commitment to a firm schedule for installation.
'3).
A commitment to equipment. changes and/or surveillance requirements in addition to those now'in effect that will provide adequate'-
assurance of SDV' operability in the~ interim until installation is' completed."
'The licensee responded to this request in Supplement 1.to the Bulletin by letter-
-dated August'15, 1980.
This response was unacceptable on~the basis that it did not provide adequate assurance that the licensee could maintain scram capability at all times during current operation.
The Bulletin and its Supplements.were
' issued to picvide'such assurance-during an interim period of operation until an ultimate resolution is achieved by changes in' system design and operating procedures.
In. view of the-foregoing considerations the NRC staff has concluded that partic-ular criteria must be satisfied in-order to provide adequate justification for-continued operation.
Criteria applicable to.the licensee's facilities are set
~
forth in Section III.
These criteria' reflect NRC judgement.that continuous monitoring of;the SDV with appropriate-indication and: alarm in the control room-
-is to be completed no later than specified.
Until the installation is compl'ete Land. operable,. surveillance checks of the SDV shall-be made at'least once per shift whenev'er'the-reactor is~ critical.
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l l L i-L These matters were the. subject.of.the discussions b'etween NRC and licensee representative Mr. R. -Janacek o'n Sentsmber 11, 1980.
The discussions provided the information on which the licensee made further commitments to satisfy'the requests of the Bulletin'and its supplements.
These commitments.were documented by. letter dated September 19, 1980 from.the licensee.
In view of the importance l-of these commitmentsEto safe operation of the facility, it is appropriate'to
-confirm the licensee's commitments by order.
L III l
- Accordingly, pursuant to the Atomic Energy Act of 1954, as amended, and the-l l
Commission's regulations in 10 CFR Parts 2 and 50, IT IS HEREBY ORDERED,-
i
. EFFECTIVE IMMEDIATELY, THAT:
1.
By-December 1,-1980, the licensee shall:
a)
Install and make operable a system to continuously monitor water i
levels in all scram discharge volumes (SDV).
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b); -The installed system shall provide for level-indication, with an associated alarm, in the control room, for each SDV.
This equipment shallsprovide sufficient information toLthe reactor operator such i.
' thatt if water accumulates in either SDV the decision about actions
,toibeitakenlcan be made in a timely fashion from the control room.
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Until the system described-in III.1 is. installed and operating satisfac-torily the licensee shall increas'e surveillance of. the -SDV water level to at.least once per~ shift. The once per shift surveillance checks. shall be at least 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. apart.
3.
The licensee shall-submit a report to the firector, Reactor Operations Inspection, Washington, D.C. 20555 and to the Director of.the appropriate NRC Regional Office, confirming installation of the continuous water level' monitoring system with provisions for indication and alarm in the control" room, at.the time the. installation is completed.
IV Any person who'has-an interest affected by this Order may request a' hearing within twenty-five1(25) days of the date of the Or'er.
Any request for a d
- hearing will.not stayfthe effectiveness'of this Order.
Any request for a
-hearing'shall be' submitted to the Secretary, U.S. Nuclear Regulatory Commission, Washington, D.'C.-20555 with a copy to the Executive Legal.-Director at the same-address.
A request for a hearing should describe.specifically the manner in which'the; petitioner's. interest is affected by this Order and should address the1 criteria set:forth'in110 CFR-2.714(d). ~ If a hearing is requested by a' person who has~an interest affected by this Order, the Commission will issue
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~an. order designating'the time and place of any such hearing.
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7-Ifjalhearing is Theld,- the. issue-to be considered at.such a hearing shall be -
whether the 1icensee should perform the actions required in'Part III of this Order in accordance with the schedule stated therein.
Operation-of the facility on terms consistent with this-Order is not' stayed
~
- by the': pendency of'any proceeding on the Order.
FOR THE NUCLEAR REGULATORY COMMISSION 1
Victor Stello, Jr.
/
Director Office'of Inspection and Enforcement-Effective Date: 0_CT 2 1980 Bethesda,-Maryland i
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