ML20236L921
Text
July 14 1995 MEMORANDUM TO: Ellis W. Merschoff, Director 8,
- Division of Reactor Projects Region !!
FROM: David 8. Matthews, Director Project Directorate !!-l Division of Reactor Projects 1/11 Office of Nuclear Reactor Regulation
SUBJECT:
TASK INTERFACE AGREEMENT (TIA)95-002 - REQUEST FOR ASSISTANCE IN THC EVALUATION OF LICENSEE POSITION ON TECHNICAL SPECIFICATION COMPLIANCE AND OPERA 81LILITY 0F THE CHENICAL AND VOLUME CONTROL SYSTEM - H. B. RO8INSON STEAM ELECTRIC PLANT, UNIT NO. 2 (TAC NO. M92012)
By memorandum dated March 30, 1995, you requested that NRR review the design and Itcensing basis for the chemical and volume control system (CVCS) charging pumps and interpret Technical Specification (TS) 3.2 regarding the operabtitty of the CVCS at H. 8. Robinson Steam Doctric Plant, Unit No. 2 (HSR).
The staff concludes that since the charging pumps at HBR do not perform any ECCS function, they are not required to be powered from normal as well as emergency power sources. Therefore, normal power alone is sufficient for these pumps to meet their operability requirements. Detatis of our review are documented in the attached memorandum from J. Calvo dated July 7, 1995.
Note that on June 3, 1995, the Itcensee submitted a TS amendment to clarify '
HBR TS 3.2 regarding the charging pumps and their operability.
We have completed our efforts on this issue and are, therefore, closing out TAC No. M92012. If you have any questions, please contact 8. Mozafart of my staff at (301) 415-2020.
Docket No. 50-261
Attachment:
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MEMORANDUM T0: David B. Matthews, Project Dire tor Project Olrectorate !!-l Division of Reactor Projects 1/II Office of Nuclear Reactor Regulation .
FROM: Jose A. Calvo, Chief Electrical Engineering Branch " ' (' ' _
Division of Engineering Office of Nuclear Reactor Regulation
SUBJECT:
REQUEST FOR TECHNICAL ASSISTANCE - EVALUATION OF H. B. ROBINSON UNIT 2 POSITION PERTAINING TO TECHNICAL SPECIFICA110N COMPLIANCE AND OPERABILITY Of CHEMICAL AND VOLUME CONTROL SYSTEM (TAC NO. M92012)
In Task Interface Agreement 95-002 sent to J. A. Zwolinskt on March 30, 1995, E. W. Merschoff (Region 11) requested that NRR review the design and Itcensing basis for the chemical and volume control system (CVCS) charging pumps and interpret Technical Specification (TS) 3.2 regarding the operability of the CVCS at H. B. Robinson Steam Electric Plant Unit 2 (HBR2).
TS 3.2.2 requires, in part, that the reactor not be made critical unless two charging pumps are operable. Operability (i.e., of the CVCS charging pumps) is defined in TS Definitton 1.3 as follows:
A system, subsystem, train, component or device shall be operable or have operability when it is capable of performing its specified '
function (s), leplicit in this definition shall be the assumption that all necessary attendant instrumentation, controls, normal and emeraency electrical power sources, cooling or' seal water, lubrication or other auxiliary equipment that are required for the system, subsystem, train, component or device to perform its specified function (s) are also capable of performing their related support function (s).
Of the three positive displacement charging pumps (A, B, and C) installed at HBR2 for the CVCS function, only two (B and C) have normal (offstte power) and emergency (cmergency diesel generators) electrical power sources; the A charging pump is powered from only the normal electrical power source.
CONTACT: P. Kang, EELB/DE 415 2779 b-@ 5 M I
David B. Matthews 1 i
i The licensee has been regularly removing either B or C charging pumps from service for routine maintenance / surveillance and has been regarding the A charging pump as a fully operable replacement for either the B or C pump removed from service. Because the resident inspector believed that the l
Itcensee's A pump replacement activity violated the TS, he asked the licensee to explain its position, j In response to the inspector's concern, the licensee reviewad the original l
CVCS design and found that the CVCS charging pumps at HBR2 are neither i designed to perform any emergency core cooling system (ECCS) functions nor given any credit in the accident analyses. Although two power sources (normal l
and emergency) happen to be available for two of the three charging pumps,
> they are designed to be run by the normal power source only. One charging l pump is adequate for normal CVCS makeup function of the reactor coolant
( system, and the use of any two pumps (i.e., considering a single failure) of q the three charging pumps meets 15 3.2.2 for making the reactor critical. The Ilcenses took a position that this was consistent with its original CVCS design and its current licensing basis, thus satisfying TS 3.2 for CVCS operability at HBR2.
To ascertain the validity of the licensee's position Region !! requested that NRR interpret TS 3.2 regarding CVCS operability.
The staff reviewed the Westinghouse plant design and Itcensing basis.for its charging pump. It found that one of the design function of the CVCS is to maintain the proper water inventory in the reactor coolant system. Because of this function, a small-break loss-of-coolant accident can be accommodated by the charging pumps, in fact In Westinghouse design two of the three charging pumps in m g plants are designed to serve as high head injection pumps during accident conditions. For those plants at which the ECCS function is performed, two of the three CVCS charging pumps are required to be on the safety 'ouses that are powered from both normal and emergency power sources, while the third pump is powered from only the normal power source.
The staff reviewed the Itcensing and design basis for HBR2's ECCS and CVCS regarding the use of the charging pumps in the updated final safety analysis report (FSAR). It also reviewed the accident analyses in Chapter 15 of the updated FSAR for the plant systems ano componsnts required for mitigating accidentt. During this review, the staff found that the ECCS function at HBR2 is performed by three passive cold leg accumulators, three safety injection (high head) pumps, and two residual heat removal (low head) pumps. Thus, the CVCS charging pumps are neither used for accident mitigation nor given any a credit in the accident analysts for HBR2.
Based on the above, the staff concludes that since the charging pumps at HBR2 do not perform any ECCS function, they are not required to be powered from normal as well as emergency power sources. Therefore, only normal power is suff1ctent for these pumps to meet their operabtitty requirements.
. (
David B. Matthews On June 3, 1995, the licenses submitted a TS amendment to clarify H8R2 TS 3.2 regarding the charging pumps and their operability.
l Docket No.: 50-261 l
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MEMORANDUM TO: William L. Axelson, Directer Y Division of Reactor Projects /
Region III \b FROM: John N. Hannon, Director Project Directorate III.1 Original signed by T. J. Kim for Division of Reactor Projects - III/IV
SUBJECT:
TASK INTERFACE AGREEMENT - FERMI 2 PERFORMANCE OF AN OPERATION WITH THE POTENTIAL TO DRAIN THE REACTOR VESSEL WITH LESS THAN THE MINIMUM A. C. ELECTRICAL POWER SOURCES AVAILABLE (AITS 495)
This memorandum responds to your November 30, 1994, request for assistance in determining the acceptability of Fermi 2 Nuclear Plant performance of reactor protection system logic functional testing with all four emergency diesel generators technically inoperable. Specifically, you requested the Office of Nuclear Reactor Regulation (NRR) to determine if the testing constituted an operation with the potential for draining the reactor vessel (OPDRV) as used in the context of Fermi 2's Technical Specification (TS) 3.8.1.2, which states )
in part, "with less than the minimum A. C. electrical power sources operable, suspend..., operations with the potential for draining the reactor vessel...."
Attached to the request were an excerpt from the resident inspector's inspection report and licensee documentation of a similar event in 1985.
Also attached were the licensee's documentation of the event and Monticello TS interpretation 3.5.E.1.& 2.
There is not a consistent definition for OPDRV throughout the industry. The attached analysis of the Fermi 2 event includes a suggested NRR definition of OPDRV and a brief analysis of the Fermi situation. The staff concludes that although many operational problems occurred, the reactor vessel was not close to being drained and Fermi 2 was not in an OPDRV condition.
If you have any questions, please contact Timothy G. Colburn, the Fermi 2 Project Manager at (301) 415-1341.
Attachment:
Fermi 2 OPDRV Analysis and Proposed OPDRV Definition ec: Richard W. Cooper, RI E. Merschoff, RII J. Dyer, RIV . I DISTRIBUTION:
Docket File PUBLIC PD31 Rdg File JRoe SVarga EAdensam (e)
TRTjader Fermi SRI mph 1111ps, RIII l CGrimes l
AChaffee DOCUMENT NAME: G:\WPDOCS\ FERMI \FE91034.NEM Te receive a copy of this document, indicate in the box: "C" .a Copy without enclosures *E* = Copy with enclosures *N* = No copy l0FFICE LA:PDIII-l B PM:PDIII-l16 PD:DRPW N 1 L lNAME CJamerson dV TColburn 4 7 JHannon 7 Mt_
lDATE 08/7.5 /95 0 08/M/95 08/n/95 4 0FFTCIAL RECORD COPY mme h
b Fermi 2 OPDRV Analysis and Proposed OPDRV Definition In response to a request from Region III dated November 30, 1994, the NRR staff evaluated the Fermi 2 licensee's performance of an October 7,1994, surveillance evolution. The region requested assistance in determining the acceptability of the performance of Protection System Logic Functional Testing with all four emergency diesel generators technically inoperable. The Fermi 2 Technical Specification 3.8.1.2 states, in part, that "with less than the minimum A. C. electrical power sources operable, suspend..., operations with a potential for draining the reactor vessel...." The region requested that the staff assist in determining whether the licensee was conducting an operation with the potential to drain the reactor vessel (OPDRV). Included with the region's request were several industry definitions of OPDRV and a description of the Fermi evolution.
There is not a consistent definition of OPDRV throughout the industry. The following is a suggested NRR definition of OPDRV and a brief analysis of the Fermi evolution. The staff concludes that Fermi 2 was not conducting an OPDRV.
Proposed OPDRV Definition The plant is in an OPDRV condition if the following exists:
- 1) An open penetration > [1 inch] in diameter. (The size threshold is based upon that size which compensatory makeup measures are able to replace water inventory loss.)
- 2) The open penetration is below the normal water level.
- 3) The penetration is not protected by an automatic isolation valve, is not isolated by a closed valve, is unisolable, or is not isolable in a timely manner.
- 4) The open penetration has the potential to uncover irradiated fuel, i
Brief analysis of Fermi 2 situation
- 1) The size of the open penetration was < 1 inch. The actual inventory loss rate was 135 gpm; the loss rate for a 1-inch penetration is 175 gpm. The reactor vessel water level fell 30 inches, from 220 inches to 190 inches. The level was restored after receipt of the torus sump high level alarm, when the sump pump was restored to service by replacing its power fuses.
- 2) The penetration was isolated in a timely manner by halting the RPS surveillance (SR) and restoring systems to normal configuration.
Other recognized Fermi operational problems:
l 1) There was a failure to return the torus sump pump to operable status l after the conduct of an SR.
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- 2) The operators displayed a lack of alertness and failed to know plant '
status. This was evidenced by their failure to understand existence of flow path, failure to recognize reactor vessel level decrease, and the fact that it required the Turus Sump Hi Level alarm to alert the operators to the situation and problem.
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- 3) Failure to learn from similar prior experience (including the failure to heed warning signs instituted after similar previous events).
- 4) Four EDGs became inoperable.
Despite Fermi's many problems, the reactor vessel was not close to being drained.
Conclusion:
Fermi was not in an OPDRV.
Principal Contributors: R. Tjader T. Colburn i
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