ML20128C001
| ML20128C001 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 01/22/1993 |
| From: | Beckman W CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9302030258 | |
| Download: ML20128C001 (8) | |
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w aan, o o,cu,,a, mw hw MKNIGAN'S PROGRE55 Big Rock Pdnt Nucleat Plant, 10269 09 31 North, Charlevo x, MI 49720 g(
/7) 841 January 22, 1993
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CJ n Nuclear Regulatory Commission Document Control Desk i
Washington, DC 20555 1
DOCKET 50-155 - LICENSE DPR 6 - BIG ROCK POINT PLANT -
RESPONSE TO EXAMINATION REPORT 50-155/0L-92002 The subject Requalification Examination report dated December 24, 1992, discussed a weakness with regard to 1) the classification of an ATWS as a site area emergency when the reactor is successfully scrammed prior to entry into the ATWS contingency urocedure, and 2) the reporting of emergency conditions-as required by 10 CfR 50.72 when the emergency condition lasts for only_ a short period of time.
With respect to these concerns, the report requested that Consumers Power Company provide a res)onse within 30 days describing our assessment of the identified weaknesses, t1e corrective actions, if any, that-have been taken or olanned to be taken, and the expected completion date for implementation of tio corrective actions.
The following provides our response as requested.
Description of Weaknesses 1)
The licensed operator training program does not provide adequate guidance on the conditions that constitute an ATWS.
Specifically, a failure of the reactor to scram when required is only considered an ATWS condition-when entry into the ATWS contingency procedure is made.
As a result, a manual reactor scram due to a failure of the reactor to scram automatically is not considered an ATWS, and therefore would not be classified as a site area emergency in accordance with the facility %.
This weakness was discussed with and will be reviewed by the facility to determine corrective actions, if-any, that will be taken to address the weakness.
O 2)
The licensed operator training program does not provide adecuate guidance Mg to ensure events requiring notification to the NRC in accorcance with n.
F 10 CFR 50.72 are reported. Specifically, the guidance.provided for a f
condition (such as an ATWS), which is classified as a site area emergency, would not be reported if the condition was corrected before y
making an NRC notification. The weakness was discussed with and will be i rd reviewed by the facility to determine corrective actions, if any, that l
will_. be taken to ensure licensed operators properly report events in i
accordance with_10 CFR 50.72.
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- t NUCLEAR REGULATORY CONNISS10N 2
BIG ROCK POINT PLANT RESPONSE TO EXAMINATION REPORT 92-002 January 22, 1993 Assessment of Item 1 With respect to Reactor Protection System (RPS) failure events (ATWS), the Big Rock Point SEP Implementation Procedures provide the following classification guidance (EAls):
_, Event Classification
. Failure to SCPAM but reactor ATWS Unusual Event subcritical and not more than 23 notches not fully inserted
. failure to SCRAM but reactor ATWS Alert subtritical and more than 23 notches not fully inserted
. Tailure to SCRAM and still ATWS Site Area critical or unknown Emorfr,<f
. Failure to SCRAM and reactor ATWS with Go tral water < 2'9" above core probability Emergency of Core Damage Consumers Power believes that the judgement difficulty that was encountered during the exercise scenario primarily dealt with two questions.
1)
Does a RPS failure to automatically actuate, but immediate successful manual Scram (indicative of sen.or failure) constitute an ATWS?
2)
If assuming so, does this situation wtrrant classification and extensive actions associated with a " Site Area Emergency"?
10 CFR 50.62(b) defines an " Anticipated Transient Without Scram" (ATWS) as an anticipated operational occurrence. as defined in Appendix A of this part followed by the failure of the reactor trip portion of the 3rotection system specified in General Design Criterion 20 of Appendix A of tais part, We believe that based upon the chove, which subsets ATWS failures to "the reactor trip portion of the protection system," that sensor / protection system input failures, followed by successful manual scram would not constitute an ATWS.
In reviewing 10 CFR 50.62 and NUREG-0460, an ATWS might be better described as a failure to shutdown the rea'ctor by control rod insertion thus requiring power redcction by one or more mitigation features required by 10 CfR 50.62.
The features for a BWR would include:
Recirculating Pump Trip Alternate Rod Injection Standby liquid control system
't NUCLEAR REGULATORY COMMISSION 3-BIG ROCK POINT PLANT RESPONSE TO EVALUATION REPORT 92-002 January 23, 1993 This thought process was prevalent prior to the issuance of system based E0P's 1
where the event based Emergency Procedure for ATWS at Big Rock Point, described an ATWS as, i
i Reactor Scram setpoint exceeded All control drives not inserted Reactor Power greater than 4%
Reactor Pressure at or above 1360 psig These syngtoms support the concern that a Reactor Scram should have occurred but an insufficient number of control rods were inserted to lower reactor power sufficiently to reduce reactor pressure which requires prompt mitigative actions.
Successful Manual Scram after an automatic initiation failure would not constitute an event meeting this level of concern.
In reviewing Appendix 1 of NUREG 0654; FEMA-REP-1; Rev 1
" Criteria for Preparation and Evaluation of Radiological Emergency Response Plans and Preparedness in Support of Nuclear Power Plants," the guidance within would require classification of an ATWS event as a Site Area Emergency if the situation constituted a:
" Transient requiring operation of shutdown systems with failure to scram (continued power generation but no core damage immediately evident)."
A successful manual Scram in response to a failure of the reactor to Scram automatically, would not result in continued power generation, thus would not meet the guidance for a Site Area Emergency.
In conclusion, Consumers Power believes that the guidelines in the Emergency Plan Implementing Procedures led to the questions concerning classification of this scenario event and not a licensed operator training. program inadequacy.
Consumers Power does agree that this type of event would require Site Emergency Plan activation but not at a " Site Area Emergency" level.
Examinee concern that a declaratien of Site Area Emergency for a failure which was promptly mitigated may have contributed to the confusion in classifying the event.
Corrective Actdons Consumers Power believes that changes to the Big Rock SEP Implementation-Procedures for classification of emergencies in this area are warranted.
Improvements which follow the guidance in NUREG-0654 can eliminate the confusion surrounding classification of ATWS events. At this time, Big Rock Point personnel support the following changes to the EAL's for ATWS events:
4
't NUCLEAR REGULATORY COMMIS$10N 4
BIG ROCK POINT PLANT RESPONSE TO EVAttlATION REPORT 92 002 January 23. 1993 EAL
_ Event Clarsification
. Reactor Protection System (RPS)
RPS Input Unusual Event failure requiring Manusi Scram failure to insert control rods
. Reactor Scram failure following ATWS Alert automatic and manual RPS actuation and reactor power > 57, l
. Reactor Scram failure ATWS Site Area requiring boron injection Emergency
. Reactor Scram failure, AlWS with General reactor power >5Y., and probability Emergency reactor water <2'9" above for Core Damage Core These EAL's closely align with the mitigative actions outlined in the BRP E0P's and would minimize operator confusion.
Following Region til review and concurrence with this a)proach, the required Emergency Plan and Implementing Procedure changes will )e initiated in It is expected that these changes will be accordance with 10 CFR 50.54(q)ing Region ill concurrence with our response to submitted within 60 days follow the weakness.
In the interim, a letter (Attachment 1) has been sent to all Shift Supervisors and Site Emergency Directors discussing the identified weaknesses and expected actions.
Assessment of itegL&
In the past, Shift Supervisors and Site Emergency Directors hwe not demonstrated difficulty in identifying reportable events in accordance with 10 CFR 50.72.
50.72 requires reportability of all Site Emergency Plan activations within one hour and Plant Implementing Procedures address this requirement.
Consumers Power Company believes that in this case, the difficulty as discussed above was in deciding that the scenario warranted an-emergency classification, not whether or not a phone notification was needed.
Had the examinees activated the emergency plan, phone notifications would have been made.
The changes to the EAL's discussed above should improve the I
classification of ATWS events insuring reportability when required. Although Consumers Power Company would not have expected this action during a training scenario, hr.d an RPS failure occurred that didn't result in an SEP activation, as a minimum the event would have been reported per 10 CFR 50.72(b)(2)(iii).
NUCLEAR REGULATORY COMMISSION 5
BIG ROCK POINT PLANT RESPONSE TO EVALUATION REPORT 92 002 January 23, 1993 Two examples of good performance in dealing with short duration events are discussed in Region 111 Inspection Report 87 023 dated December 23, 1987. On January 31, 1987 at 0440 hours0.00509 days <br />0.122 hours <br />7.275132e-4 weeks <br />1.6742e-4 months <br /> smoke was observed in the station power room.
An " Alert" was declared at 0445 hours0.00515 days <br />0.124 hours <br />7.357804e-4 weeks <br />1.693225e-4 months <br /> and terminated foar minutes later. On June 23, 1987 a fire alarm was received at 0321 hours0.00372 days <br />0.0892 hours <br />5.30754e-4 weeks <br />1.221405e-4 months <br /> due to an overheated dehumidifier cord.
The Shift Supervisor declared an Alert at 0325 hours0.00376 days <br />0.0903 hours <br />5.373677e-4 weeks <br />1.236625e-4 months <br />, activated portions of the plan and terminited at 0440 hours0.00509 days <br />0.122 hours <br />7.275132e-4 weeks <br />1.6742e-4 months <br />. As discussed in the report, the Inspectors reviewed th documentation related to these events and concluded that classifications and notifications had been performed promptly and within time frame goals.
Although Consumers Power Company does not believe any corrective action (including operater training program changes) is warranted in this area, the i..terim memo attached to this letter provides a reminder of reporting expectations to the responsible personnel.
Should any questions or concerns arise regarding this response, please contact us.
Robert J Alexander for William L Beckman (Signed)
Willia.n L Beckman Plant Manager CC:
Administrator, Region 111, USNRC NRC Resident inspector - Big Rock Point AlTACHMENT
~
$UA To:
Shitt. Supervisors /On Call Superintendents From:
WJTrubilowicz I
CONSUMERS POWER Date:
January 20, 1993 COMPANY
Subject:
BIG ROCK POINT--
Internal EMERGENCY CLASSTFICATIONS F)R-correnadence SilORT TERM EVEN'13 WJT 93 005 CC:
PRC Chairman KAWooster i
Attachment Excerpts from Requa.litication Examination Report
- 50-155/OL-92 02 During the 1992 Requalification Examinations, some difficulty was identified in the area of classification of short term events and activation of the Site Emergency Plan-(SEP) under those' conditions.-
The type of event that is being referred to is a condition that occurs but the immediate actions taken by the crew corrects the condition before the SEP could be implemented.
During the exam scenario, a
scram setpoint was
- reached, no automatic scram occurred, and as directed by the EOPs, the operator inserts a manual scram and all rods insert.
During the scenario an SEP declaration (Site Area Emergency) was not declared for this condition.
In the short period of time between reachingL the setpoint and manually scramming an RPS failure had occurred.
- However, was this an ATWS?,
and what' is the appropriate -SEP response is the area of confusion.-
The NRC, as_ discussed in_the attached portions of the Inspection report, would= define this as an ATWS requiring a
" Site Area Emergency" -classification and associated reporting requirements.
Although further discussions with the NRC will be forthcoming regarding this position, in the interim the following guidance should be followed.
Using the current SEP, you are expected to declare the level of emergency based on the worst condition that bas occurred during the event nnd evaluate the situation before downgrading or exiting the -
SEP.
In the case referenced above, you should declare a Site Area Emergency and activate our facili'.ies to'that level, o
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2 Downgrading or terminating high level events (Site Area or General Emergencies) would require careful consideration and tr.ost -likely consultation _with the TSC.
In events that are classified'as an Alert or NUE, provisions in the procedures allow classification but the SED has some discretion as to the level of activation.of the' facilities (REF: Vol 9A, EPIP-3A, Section 3.4).
The same expectation applies to reporting events of thin type as per Vol 1, Sect 6.1,-the event is to be reported regardless of the duration of occurrence.
This guidance is intended to - be temporary until an indepth evaluation of the situation can be accomplished and the SEP revised to'give clear direction.
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T_ raining. Operations. Secutity. Rad Ptg.tastion During exam development, the following weaknessos were identified and discussed with the facility:
During exam preparation, a breakdown in exam security occurred when a member of the roqualification exam development team provided training to licensed oporators scheduled to take the examination.
The facility took immodlato actions to notify the NRC, remove the individual from the exam development team, and substitute portions of the proposed examination previously developed with now exam material.
In addition, the actions taken by the facility to provent recurrenco appear to be adequate.
The licensed operator trainin program does not provido
-jg) adequate guidance on the cond tions that constitute an ATWS.
Specifically, a failuro 02 the reactor to scram when required is only considered an ATWS condition when entry into the ATHS contingency procedure is made.
As a result, a manual reactor scram due to a failure of the reactor to scram automatically is not considered an ATWS, and therefore would not be classified as a site area omorgency in accordanco with the facility's emergency plan.
This weakness was discussed with and will be reviewed by.the facility to determina corrective actions, if any, that will be taken to address the weakness.
The licensed operator training program does not provide r
adequate Quidance to ensure ovents requiring notification to the NRC in accordance with 10 CFR 50.72.
are reported.
Specifically, the guidance provided for a condition (such as an ATWS), which is classified as a sito area emergency, would not be reported if the condition was corrected before making an NRC notification.
The weakness was discussed with and will be reviewed by the facility to determine corrective actions, if any, that will be taken to ensure licensed operators properly report events in accordance with 10 CFR 50.72.
o EOP-1, " Primary System Control, indicates that if pressure is less than 1435 psig, pressure is to be controlled Icss than 1385 psig by various means, supplomonted by the turbine bypass valve, reactor cicanup and reactor cicanup blowdown.
A caution in the procedure states "The reactor cican-up cystem non-regenerative heat exchanger may not have sufficient capacity to remove decay heat until nearly a week following reactor shutdown.
Premature use of.the 2
-.