ML18127A678

LER 1978-007-00 for St. Lucie Unit 1, Technical Specification 4.3.1.1.3 RTD Response Time

ML18127A678
Person / Time
Site:	Saint Lucie
Issue date:	02/17/1978
From:	Schmidt A Florida Power & Light Co
To:	O'Reilly J NRC/IE, NRC/RGN-II
References
PRN-LI-78-48 LER 1978-007-00
Download: ML18127A678 (3)

Text

February 17, 1978 PRN-LI-78-48 Mr. James P. O'Reilly, Director, Region Office of Inspection and Enforcement II U. S. Nuclear Regulatory Commission 230 Peachtree Street, N. W., Suite 1217 Atlanta, Georgia 30303

Dear Mr. O'Reilly:

REPORTABLE OCCURRENCE 335-78-7 ST ~ LUCIE UNIT 1 DATE OF OCCURRENCE: FEBRUARY 3, 1978 TECHNICAL SPECIFICATION 4.3.1.1.3 RTD RESPONSE TIME The attached Licensee Event Report is being submitted in accordance with Technical Specification 6.9 to provide prompt notification of the subject occurrence.

Uery truly yours, AD D. Schmidt Vice President Power Resources MAS/bab Attachment cc: Robert Lowenstein, Esquire Director, Office of Inspection and Enforcement (40)

Director, Office of Management Information and Program Control (3)

PLEASE PRlNT ALl REOUlREO INFORMATlONj UCENSEE LICENSE EVENT NAME L1CENSE NUMBER TYPE TYPE L L 0 0 0 0 0 0 0 0 1 1 1 1 ~01, 0+1 E

>,~S S 1

~

8 9 14 15 25 26 30 31 32 AEPQRT REPOAT CATEGORY TYPE SOURCE, DOCKET NUMBER EVENT DATE AEPQAT CAlf

+11 CONT ~T ~L 0 5 0 0 3 3 5 0 2 0 3 7 8 0)2 1 7 7 8 8 57 58 59 60 61 68 69 74 75 60 EVENT OESCRIPTION I]g echnica] Specification Table 3.3-2(Reactor Protective Instrumentation Response Times) 8 9 60 i@3 does not include allowance for resistance temperature detector (RTD) response time, 8 9 60 Q4 therebv preventing full compliance with Technical Specification 4.3.1.1.3 (response time 8 9 60 Ij89 testin . In addition the RTD res onse times of selected channels are apparently greate 60

.'Q6 than the 5-second value initiall used b the NSSS vendor in the applicable setpoint 8 9 PAME 80 SYSTEM CAUSE C MFCNENT C MPQNENT CODE CODE COMPONENT CODE SL'PDUER MA1NUFACTUPER

~IA 8 9 10

~B 1 R S T R 0 R 3 7 0 48 11 12 17 47 C" USE DESCRIPTION IB The RTDs are mounted in instrument wells. Apparently, changes in the parameters 8 9 c0 9 governing the'esponse of an RTD in an instrument well affect the overall response time.

8 9 DESCRIPT:CN 60 0 In addition, St. Lucie Unit 1 and other similar plants have had difficulty verifying the 89 Fi CSJTY METHOD QF 60 STATUS POWER OTHER S'TATUS DISCOVERY OiSCQVERY

~E ~OS NA NA 8 9 10 12 13 44 FORM OF JLCTIVlTY CON ENT

~

~

RELEASED OF RELEASE AMOUNT OF ACTIVRY LOCATION OF RELEASE 2 ~Z NA NA 8 9 10 11 PEASONNEL EXPOSURES NUMBER TYPE OESCA1PT1ON NA PEASONNEL INJURIES 0 0 0 NA 8 9 11 12 80 ROBABLE CONSEGUFNCES NA 8 9 60 LOSS OR OAMAGE TO FACILITY TYPE OESCA1PT1ON Lzl NA PUBLICITY ADDITIONAL FACTORS a e two for continuation of Event Description and Cause Description.

80

E Reportable Occurren 335-78-7 Licensee event Report page Owo'~

Event Description (continued) analysis. his is based on measurements made by a consultant in mid-January, 1978. The consultant reported the results on February 3, 1978. Although the measured response times are greater than 5 seconds, they are less than the revised value of 8 seconds contained in a proposed Technical Specification amendment which has been submitted to the NRC (see "Cause De-scription"). This is the first occurrence of this type at St. Lucie Unit l. (335-78-7)

Cause Descri tion (continued) 5-second response time assumed in the NSSS setpoint analysis.

As a result of the param tric uncertainties and the measure-ment difficulties, the NSSS vendor had been requested in 1977 to re-evaluate the appropriate setpoints using a response time greater than 5 seconds. In December, 1977 the NSSS vendor responded with an evaluation that supported response time" o.

up to 8 seconds. A proposal to incorporate the 8-second value in Table 3.3-2 was forwarded to the NRC by letter L-78-39 dated February g, 1978.

All RTDs tested had response times less than 8 seconds, so no further action beyond the Technical Specification change proposal is planned at this time.