United States Nuclear Regulatory Commission - Protecting People and the Environment


ACCESSION #: 9707170088



                             ATTACHMENT (1)



10 CFR PART 21 REPORT CONCERNING FAILURE OF

MAIN STEAM HEADER RADIATION MONITORS

SUPPLIED BY NUCLEAR RESEARCH CORPORATION



Calvert Cliffs Nuclear Power Plant, Units 1 and 2



Docket Nos: 50-317 and 50-318



(i)       Name and Address of Individual Making Notification:



          C. H. Cruse, Vice-President, Nuclear Energy Division

          Baltimore Gas and Electric Company

          Calvert Cliffs Nuclear Power Plant

          1650 Calvert Cliffs Parkway

          Lusby, MD 20657



(ii)      Basic Component Affected.



          Nuclear Research Corporation Extended Range Gamma Scintillation

          Detector MD-55E(V3)



(iii)     Firm Supplying Component:



          Nuclear Research Corporation

          125 Titus Avenue

          Warrington, PA 18976



(iv)      Nature of the Defect



          The Main Steam Reader Radiation Monitor detectors are located

          in the Main Steam Isolation Valve (MSIV) room.  The detectors

          are mounted adjacent to their respective main steam line, close

          to the containment penetration, upstream of the Main Steam

          Safety Valves (MSSVs).  The Main Steam Header Radiation

          Monitors arc designed to measure potential noble gas releases

          to the environment in the event of primary-to-secondary steam

          generator tube leakage concurrent with lifting of the MSSVs,

          atmospheric dump valves or the exhaust from the turbine-driven

          auxiliary feedwater pumps.  The purpose of the Main Steam

          Header Radiation Monitors is to



                             ATTACHMENT (1)



10 CFR PART 21 REPORT CONCERNING FAILURE OF

MAIN STEAM HEADER RADIATION MONITORS

SUPPLIED BY NUCLEAR RESEARCH CORPORATION



          detect significant radiological releases and Provide meaningful

          release information for offsite emergency actions.



          If a Main Steam Header Radiation Monitor is inoperable, then in

          accordance with Technical Specification 3.3.3.1, Action

          Statement (30) and the Emergency Response Plan Implementation

          Procedures, the preplanned alternate method of monitoring

          effluent noble gas in the respective main steam header is

          implemented.



          The Unit Nos. 1 and 2 safety-related Main Steam Header

          Radiation Monitors were recently replaced in accordance with

          approved modifications.  The Unit 1 radiation monitors were

          tested and declared OPERABLE in early May 1997.  The Unit 2

          radiation monitors were tested and declared OPERABLE in late

          May 1997.  In early June 1997, the Unit 1 Main Steam Header

          Radiation Monitors successfully passed their first monthly

          channel functional surveillance tests required by Technical

          Specification 3.3.3.1.  On June 6, 1997, during performance of

          their first monthly channel functional test, Unit 2 Main Steam

          Header Radiation Monitors Nos. 21 and 22 failed to respond

          during a checksource test, were declared not OPERABLE, and the

          alternate preplanned monitoring method was implemented.  On

          June 10, 1997, following evaluation of troubleshooting results

          on the Unit 2 Main Steam Header Radiation Monitor detectors,

          confirmatory tests performed on the Unit 1 Nos. 11 and 12 Main

          Steam Header Radiation Monitors revealed that they also failed

          to respond during a checksource test.  These Unit 1 radiation

          monitors were removed from OPERABLE status, and the alternate

          preplanned monitoring method was implemented.



                                    2



ATTACHMENT (1)



10 CFR PART 21 REPORT CONCERNING FAILURE OF

MAIN STEAM HEADER RADIATION MONITORS

SUPPLIED BY NUCLEAR RESEARCH CORPORATION



          Although the inoperability of Nos. 11 and 12 (Nos. 21 and 22)

          Main Steam Header Radiation Monitors has not affected Unit 1

          (Unit 2) operation, the detectors failed to operate as exported

          over the required temperature range.  This defect resulted in

          the inability of these safety-related components to perform

          their intended function (i.e., detect significant radiological

          releases and provide meaningful release information for offsite

          emergency actions).  The Main Stem Header Radiation Monitors

          are passive monitoring instrumentation that do not interface

          with any other safety-related equipment.  However, these

          radiation monitors are designated safety-related and are

          designed to be operational during and following the event The

          details of the discovery and nature of the defect are provided

          below.



          Numbers 21 and 22 Main Steam Header Radiation Monitors were

          replaced per an approved modification during the Unit 2 spring

          1997 refueling outage.  Following the installation, Engineering

          Test Procedures were performed which included the performance

          of checksource tests.  The monitors satisfactorily passed all

          requirements of the Engineering Test Procedures (perforated

          with Unit 2 in MODE 5 and a MSIV room ambient temperature of

          approximately 90 Degrees F) and were placed in an OPERABLE

          status in late-May 1997.



          On June 6, 1997, during the performance of the first monthly

          channel functional test required by Unit 2 Technical

          Specifications surveillance requirements, Nos. 21 and 22 Main

          Steam Header Radiation Monitors failed to respond during the

          checksource test.  The radiation monitor was removed from

          OPERABLE status and the alternate preplanned monitoring method

          was implemented.  Troubleshooting on No. 21 Main Steam Header

          Radiation Monitor determined that the checksource was properly

          aligned with respect to the collimating hole during the



                                    3



                             ATTACHMENT (1)



               10 CFR PART 21 REPORT CONCERNING FAILURE OF

                  MAIN STEAM HEADER RADIATION MONITORS

                SUPPLIED BY NUCLEAR RESEARCH CORPORATION



          checksource test.  However, no response from the detector was

          noted during subsequent checksource tests.  Further

          troubleshooting found that no response was seen when the

          checksource was placed directly on the detector.  Satisfactory

          source strength of the checksource was confirmed by placing it

          directly on a personnel contamination gamma detector.  Several

          checksource tests were then performed on No. 22 Main Steam

          Header Radiation Monitor and no detector response was noted.



          During evaluation of the troubleshooting results above, it was

          suspected that a generic problem may exist with detector

          performance.  Therefore, on June 10, 1997, confirmatory

          checksource tests were performed on the similar Unit 1 Nos. 11

          and 12 Main Steam Header Radiation Monitors.  Both Unit 1

          radiation monitors failed to respond to a checksource test,

          were removed from OPERABLE status, and the alternate preplanned

          monitoring method was implemented.  (Note: !he Unit 1 Main

          Steam Header Radiation Monitors were replaced earlier in 1997

          per an approved modification.  These new Unit 1 radiation

          monitors were tested satisfactorily (with Unit 1 operating in

          MODE 1 and MSIV room ambient temperature approximately 110

          Degrees F - 120 Degrees F), in accordance with similar

          Engineering Test Procedures as those performed on the Unit 2

          Main Steam Header Radiation Monitors.  The Unit 1 Nos. 11 and

          12 Main Steam Header Radiation Monitors were placed in an

          OPERABLE status in early-May 1997.  These Unit 1 radiation

          monitors satisfactorily completed their first monthly channel

          functional test required by Technical Specification

          surveillance, requirements earlier in June 1997.  The MSIV room

          ambient temperature was still approximately 110 Degrees F -120

          Degrees F.]



                                    4



                             ATTACHMENT (1)



               10 CFR PART 21 REPORT CONCERNING FAILURE OF

                  MAIN STEAM HEADER RADIATION MONITORS

                SUPPLIED BY NUCLEAR RESEARCH CORPORATION



          Following confirmation that a generic detector performance

          problem existed, additional troubleshooting (using No. 21 Main

          Steam Header Radiation Monitor) determined that the detectors

          were sensitive to elevated temperatures.  With MSIV room

          ambient temperature measured at approximately 135 Degrees F, a

          contact temperature reading on No. 21 Main Steam Header

          Radiation Monitor detector measured approximately 155 Degrees

          F.  This detector was removed from the Unit 2 MSIV room,

          allowed to cool to approximately 80 Degrees F, and was returned

          to the MSIV room.  A checksource test was immediately performed

          with satisfactory results.  However, subsequent checksource

          tests, performed at approximately 3 to 5 minute intervals,

          showed a degrading detector performance.



          Checks utilizing secondary calibration button check sources

          were performed on No. 21 Main Steam Header Radiation Monitor

          detector after cooling the detector to approximately 80 Degrees

          F, with the detector at a MSIV room ambient temperature of 135

          Degrees F, and with the detector at approximately 155 Degrees

          F.  Degraded detector performance was noted at the elevated

          temperatures.



          Vendor documentation states that this detector should be

          capable of operating satisfactorily over a temperature range of

          -22 Degrees F to +194 Degrees F.  Vendor environmental test

          data appeared to substantiate the published detector operating

          temperature range.  However, based upon the results of the

          troubleshooting and the vendor specifications, it was concluded

          that the detectors were not operating as expected over the

          required temperature range.  The cause of the inoperability of

          the Main Steam Header Radiation Monitors was determined to be

          inadequate vendor design of the detector temperature

          compensation circuit.  Baltimore Gas and Electric Company (BGE)

          design specification for the new safety-related Main Steam

          Header Effluent



                                    5



                             ATTACHMENT (1)



               10 CFR PART 21 REPORT CONCERNING FAILURE OF

                  MAIN STEAM HEADER RADIATION MONITORS

                SUPPLIED BY NUCLEAR RESEARCH CORPORATION



          Monitors requires that these detectors be able to operate at a

          continuous temperature of 170 Degrees F.  In addition, the

          design specifications state that these radiation monitors shall

          meet the requirements of Regulatory Guide 1.97, Table 3,

          Category 2, Type E Variable, "Vent From Steam Generator Safety

          Relief Valves or Atmospheric Dump Valves," in which a Type E

          Variable is defined as those variables to be monitored as

          required for use in determining the magnitude of the release of

          radioactive materials and continually assessing such releases.

          The design specifications define the safety classification of

          the Main Steam Header Radiation Monitors stating, in part, that

          all safety-related equipment must be manufactured and procured

          under a 10 CFR Part 50, Appendix B program and that the

          requirements of 10 CFR Part 21 apply.



(v)       Date on Which Defect Was Identified:



          On June 6, 1997, Issue Reports were written documenting that

          Nos. 21 and 22 Main Steam Header Radiation Monitors had failed

          their checksource tests during surveillance testing and were

          declared not OPERABLE.  On June 10, 1997, an Issue Report was

          written documenting that the Unit 1 Main Steam Header Radiation

          Monitors had failed the requested checksource tests (and

          declared not OPERABLE) that were performed due to the generic

          concern with all the Main Steam Header Radiation Monitors.  On

          July 1, 1997, we submitted a Special Report to the Nuclear

          Regulatory Commission concerning the inoperability of the Unit

          1 and Unit 2 Main Steam Header Radiation Monitors discussed

          above.  The extent of the deviation (i.e., departure from the

          design specification that the detectors be able to operate at a

          continuous temperature of 170 Degrees F) that resulted in the

          failed surveillance testing and inoperability of the Main Steam

          Header



                                    6



                             ATTACHMENT (1)



               10 CFR PART 21 REPORT CONCERNING FAILURE OF

                  MAIN STEAM HEADER RADIATION MONITORS

                SUPPLIED BY NUCLEAR RESEARCH CORPORATION



          Radiation Monitors, identified the inability of these safety-

          related components to provide meaningful radiological release

          information as designed.



(vi)      Number and Location of Components:



          There are two Nuclear Research Corporation Extended Range Gamma

          Scintillation Detectors [MD-55E(V3)], one for each main steam

          line, located in the MSIV room for each unit.



(vii)     Corrective Actions:



          We have communicated the detector performance problem to the

          vendor.  The detectors and associated pre-amplifiers were

          returned to the vendor for confirmatory testing and

          modification, if necessary.  The vendor confirmed that the

          detectors were not operating as expected over the required

          temperature range and that the originally supplied

          environmental test data was incomplete.  A proposed

          modification to the detector temperature compensation circuit

          has been temporarily implemented and is undergoing initial

          vendor testing.



          Baltimore Gas and Electric Company has prescribed additional

          testing to be performed by the vendor on the proposed

          modification.  Following the completion of this testing and BGE

          acceptance of the results, formal factory acceptance testing of

          the modified detectors will occur.  Upon satisfactory

          completion of the factory acceptance testing, BGE acceptance

          testing per approved Engineering Test Procedures will be

          performed.  We plan to conduct this acceptance testing at

          Calvert Cliffs with the units operating and the MSIV rooms at

          elevated temperatures (similar conditions to when the problem

          with the detector response was first identified).  Following

          successful completion of the site acceptance tests, the Unit 1

          and Unit 2 Main Steam



                                   7



                             ATTACHMENT (1)



               10 CFR PART 21 REPORT CONCERNING FAILURE OF

                  MAIN STEAM HEADER RADIATION MONITORS

                SUPPLIED BY NUCLEAR RESEARCH CORPORATION



          Header Radiation Monitors will be returned to OPERABLE status.

          The estimated completion date for the return of all Main Steam

          Header Radiation Monitors to OPERABLE status is August 31,

          1997.



          An INPO Nuclear NETWORK message will be issued to make other

          industry personnel aware of this problem.



(viii)    Other Advice Related to Purchasers or Licensing:



          None.



                                    8



     POWER REACTOR                      EVENT NUMBER: 32621



FACILITY: CALVERT CLIFFS      REGION: 1     NOTIFICATION DATE: 07/14/97

UNIT: [1] [2] [ ]             STATE: MD     NOTIFICATION TIME: 14:11 [ET]

RX TYPE: [1] CE, [2] CE                     EVENT DATE:        06/06/97

                                            EVENT TIME:        00:00[EDT]

NRC NOTIFIED BY: PETER KATZ                 LAST UPDATE DATE:  07/14/97

HQ OPS OFFICER: STEVE SANDIN



                                                  NOTIFICATIONS

EMERGENCY CLASS: NOT APPLICABLE

10 CFR SECTION:                              HERB WILLIAMS       RDO

CCCC 21.21          UNSPECIFIED PARAGRAPH



                                             VERN HODGE (VIA FAX) NRR



UNIT SCRAM CODE RX CRIT  INIT PWR INIT RX MODE    CURR PWR CURR RX

MODE



1         N         Y      100     POWER OPERATION  100   POWER OPERATION

2         N         Y       99     POWER OPERATION   99   POWER OPERATION



                               EVENT TEXT



THE LICENSEE IS MAKING A 10 CFR PART 21 NOTIFICATION.



THE LICENSEE IDENTIFIED THAT THE RECENTLY INSTALLED MAIN STEAM

HEADER

RADIATION MONITORS, EXTENDED GAMMA SCINTILLATION DETECTORS

SUPPLIED BY

NUCLEAR RESEARCH CORPORATION, MODEL #MD-55E(V3), FAILED A CHECK

SOURCE

VERIFICATION UNDER NORMAL OPERATING CONDITIONS WITH AMBIENT

TEMPERATURES

BETWEEN 110 AND 120 Degrees F.  THE DESIGN SPECIFICATION REQUIRES

OPERATION UP TO 170 Degrees F WHICH WAS WITHIN THE VENDOR SUPPLIED

OPERATING RANGE OF -22 TO 194 Degrees F.  THE PROBLEM APPEARS TO BE

RELATED TO THE TEMPERATURE COMPENSATION.  THE DETECTORS WERE

DECLARED

INOPERABLE AND REMOVED FOR REPAIR AT THE VENDOR'S FACILITY.  THIS

PLACES

BOTH UNITS IN TECHNICAL SPECIFICATION 3.3.3.1, ACTION STATEMENT (30), AND

IN THE EMERGENCY RESPONSE PLAN IMPLEMENTATION PROCEDURES WHICH

ALLOWS AN

ALTERNATE METHOD OF MONITORING EFFLUENT NOBLE GAS IN THE

RESPECTIVE MAIN

STEAM HEADER.



THE LICENSEE PLANS TO INFORM THE NRC RESIDENT INSPECTOR.



*** END OF DOCUMENT ***



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