ML19338F579
| ML19338F579 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 10/02/1980 |
| From: | Stello V NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| To: | VERMONT YANKEE NUCLEAR POWER CORP. |
| Shared Package | |
| ML19338F578 | List: |
| References | |
| IEB-80-17, NUDOCS 8010200620 | |
| Download: ML19338F579 (7) | |
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,I UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION-
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din the Matteriof-
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Docket No.:
50-271
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Vermont Yankee Nuclear Power
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Corporation.
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'(Vermont Yankee' Nuclear Power
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Station)
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CONFIRMATORY ORDER f
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Vermont Yankee Nuclear Power Corporation (the " licensee") is the holder of Facility.0perating License No.'DPR-28 (the " license") with'an expiration date of December'11, 2007 which authorizes operation of the. Vermont Yankee Nuclear Power Station (the " facility").
II On June 28,-1980, during a routine shutdown of the Browns Ferry Nuclear Power Station Unit 13're~ actor, a manual scram from approximately 35% power failed to insert all of the control' rods.
Three scrams were initiated over a period of about 14 minutes to achieve full insertion of all of the control rods.
-The control' 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 the 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 accumulation of water.
This accumulation of water was not. detected by the-jsoloaoqq g
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' reactor pro.ectisn system because'it stayed 0ithin the SDV headers and did-not~
' drain tolthe' scram discharge' instrumented volume (SDIV).
E On~ July 2,:1980, al team of NRC Headquarters representatives went-to the Browns-Ferry 7;itefto-gather detailed information,on the event and its related considera-
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tions.
IE Bulletin No. 80-17, " Failure o'f:76 of'185 Control Rods to Fully Insert
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During a Scram at'a BWR" was issued o'n July l3, 1980 and requested actions to-be-taken thr all flicenseesiof operating General Electric designed Boiling Water Reactors..Among the. actions requested were the~following:
'"1.
Within 3 days from the date of this Bulletin, perform surveillance tests to verify'that there is no significant amount of water in the
- Scram Discharge Volume'(SDV) and associated piping and that the SDV vent valves are operable and vent system is free of obstruction."-
P "3.
At the conclusion of: the ' scram tests and all other scrams, verify
-.that all vent ~1ines'in'the SDV are functional.
Verify that there is no significant amount of water in the SDV andl associated piping."
'!S.
Prview and develop surveillance procedures such that scram discharge volume-is monitored' daily for residue waternfor 6 days and, if
-i results;are acceptable,.theLinterval-may'be extended to 7 days."
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Additional. actions aph_icable to these BWR facilities were requested in
. Supplement Nc-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 I requested.the following:
"B.
Actions tc be Taken by BWR Licensees and Completed by September 1,
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1980:
1)-
In' stall.a system to continuously monitor water levels in all-a scram discharge volumes.
Continuous recording and alarm features must.be-included in the design.
Consideration should be givi.. to use of diverse.Jvel sensors in this (these) system (s).
The design. installed should represent the design with the highest.
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. level of reliability compatible with completion of installation by' Sept mber 1, 1980.. Provide a written description of the system design to the: NRC Regional Office.-
IfLinstallation by September 1, 1980 is not possible, by August 15, 1980, j
submit't'o the NRC Regional Office:
1)
Documentation in detail why the installation ~cannot be completed
-by September.1, 1980.
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5 commitment ltoafirmscheduleforinstallation.'
3). 'A commitment to' equipment. changes and/or surveillance requirements
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in addition to'those now in'effect that will provide adequate
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assurance of SDV operability in the interim until installation 7
i-s completed."
s The-licensee responded to this request in Supplement 1 to the Bulletin t / letter dated August 15, 1980. This response was unacceptable on the basis that it did
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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'providetsuch 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 fo' egoing considerations the NRC staff has concluded that partic-4.
r 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
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monitoring.of the.SJV with' appropriate indication and alarm in'the control room
'is'to be completed no later.than spscified.
Until.the installation is complete
' shift whenever.the: reactor is'~ critical.
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5-These matters;were the subject-of the discussions between NRC and licensee representative Mr..W._Conway.on'. September 12, 1980.
The discussions provided the-information-on which the-licensee made further commitments to satisfy the requ'ests'of the Bulletin and..itsl supplements.
These commitments were documented by. letter dated September 19, 1980 from the licensee.
In view cf the'importance'of these commitments to' safe operation of-the facility, it is-appropriate to confirm the -licensee's-commitments -by order.
III
.Accordingly, pursuant to the Atomic Energy Act of 1954, as amended, and
'the Commission's regulations ~in 10 CFR Parts 2 and 50, IT IS HEREBY ORDERED, EFFECTIVE IMMEDIATELY, THAT:
1.
. Until the plant is shut down for refueling, scheduled for Septenber 26, 1980
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the licensee'shall increase surveillance of the scram discharge volume (SDV) water leve to at least once per shift.
The once p c shift surveillance checks shall be at least 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />s-apart.
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Prior to restart following the refueling outage scheduled for September 26,
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- 1980 the licensee shall:
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~a)
Install-and make operable a system to continuously monitor witer
'levelsiin all SDV's.
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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-shall provide sufficient jnformation to the reactor operator such
~that:if water accumulates in either SDV the decision about actions to be ta>en can be'made in a timely fa'shion from the control room.
3.-
The licensee shall submi?. a report to the Director, Reactor Operations Inspection, Washington, D.C. 20555 and to the Director of the appropriate-Regional Office, confirring installation of the continuous water level monitoring 3ystem, 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-five (25). days of the date of the Order.
Any' request for a hearing will not stay the effectiveness of this Order.
Any request for a hearing shalll 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 the criteria: set forth,in-10 CFR'2.714(d).
If a hearing is requested by a person who has an-jnterest-affected by this Order, the. Commission will issue an order, designating the time and place of any such hearing.
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. f 7' a hearing-is' held, the issue to be considered'at such a hearing shall be.
shether the~ licensee'should perform the actions' required in Part III of this
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Order'in accordance with'the schedule stated therein.
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' Operation of-the facility on terms consistent with this Order is not stayed by the pendency of.any proceeJing on the Order, t
FOR THE NUCLEAR REGULATORY COMMISSION Q,r -l -
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W6W Victor Stello,-Jr.'
~ Director
-Office of. Inspection and Enforcement.
-Effective Date:00T 2 1980 Bethesda, Maryland-4 4
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