HL-2006, Application for Amends to Licenses DPR-57 & NPF-5,revising TS to Remove Main Steam Line Radiation Monitor Reactor Scram & Group Isolation Functions,Per BWROG Topical Rept NEDO-31400, SE for Eliminating BWR MSIV Closure..

From kanterella
(Redirected from ML20115G665)
Jump to navigation Jump to search
Application for Amends to Licenses DPR-57 & NPF-5,revising TS to Remove Main Steam Line Radiation Monitor Reactor Scram & Group Isolation Functions,Per BWROG Topical Rept NEDO-31400, SE for Eliminating BWR MSIV Closure..
ML20115G665
Person / Time
Site: Hatch  Southern Nuclear icon.png
Issue date: 10/19/1992
From: Beckham J
GEORGIA POWER CO.
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20115G669 List:
References
HL-2006, NUDOCS 9210260293
Download: ML20115G665 (17)
v • d • e


Text

. .

i l Gcygic P'Jower Compmy  ;

40 invometa Cents Partway _l

- Post Offee Box 1295

- Dwmingham. Nabama 35201 ~

Telepone 20S 877-7279 - .

l M

J. T. Beckham, Jr. Georgia b

Power Vice President Nuclear Hatch Project the wut?s n eMmc syuem -

HL-2006 003397 October 19, 1952 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555 PLANT HATCH.- UNITS 1,-2 NRC 00CKETS 50-321, 50-366 s OPERATING LICENSES DPR-57 NPF-5 REQUEST TO REVISE TECHNICAL SPECIFICATIONS:

TO REMOVE THE MAIN- STEAM LINE RADIATION MONITOR

' REACTOR-SCRAM AND GROUP ISOLATION FUNCTIONS l

Gentlemen:

1 1 In accordance with the provisions of 10 CFR 50.90, as _ required by 10 CFR 50.59(c)(1), Georgia Power Company (GPC) hereby proposes changes to the Plant l Hatch Units 1 and 2 Technical Specifications (TS), Appendix A -to Operating

!- Licenses DPR-57 and NPF-5.

I The proposed amendment eliminates the main . steam isolation valve (HSIV) closure, the reactor scram, and'the control room pressur.ization functions of

the main steam line radiation monitors (MSLRMs). -The proposed change is i consistent with the BWR Owners Group (BWROG) Topical Report NED0-31400,

[- " Safety Evaluation for Eliminating the- Boiling Water Reactor Main Steam

Isolation Valve Closure Function and Scram Function F Raaiation Monitor."' The proposed change' provides proved -im(of the availMain Steam

&uility of Line the main condenser for removal _of decay heat--and aids in. minimizing _

inadvertent reacter scrams and engineered safety' feature actuations.

In addition, this amendment proposes changes to the' references to the

_ hydrogen water chemistry footnotes in the isolation tables, and to ~an action

, statement concerning the off-gas post treatment monitors.

F -

l Enclosure 1 provides-a detailed description of ~the proposed changes and circumstances necessitating the -change request. Enclosure . 2 details the ,

bases for GPC's determination the proposed changes do not involve significant: ,

hazards consideration. Enclosure 3 provides page change instructions for incorporating the proposed change. Following the enclosures are the proposed changed TS pages, as well. as- the appropriate markups.

To allow time for procedure- revision and orderly incorporation into copies of the TS, GPC requests-the proposed amendment, once approved, be

. - issued with an effective date to be no later than 60 days from the date of-issuance of the amendment.

P 9210260293 921019

PDR ADOCK 05000321 -

-P .PDR- l j.

1-- ~ ~ * - ' -n

. GeorgiaPower1 U.S. Nuclear Regulatory Commission a

October _19, 1992

- Page Two-In accordance with the requirements of 10 CFR 50.91, the designated state official will be sent a copy of this letter and all applicable enclosures.

Mr. .

J. T.- Beckham, Jr. states he is duly- authorized to exe' cute this oath on behalf of Georgia ' Power Company, and to the best of:his knowledge ano-belief, the facts set forth in this letter are true..

GEORGIA POWER COMPANY ,

By:. M

. T. Beckham, Jr. I Sworn to and subscribed before me this (( ay of. th IAA) _1992.

c l& dA1% Notary Public ,

, Ny Commladori Expires Aug. 8.1995 0CV/cr

Enclosures:

1. Description of-Proposed Change.. - -

., 2. No Significant Hazards Consideration Determination

3. cRevision Insertion Instructions cc: Geora-la Power-Company Mr. H. L. Sumner,1 General Manager - Nuclear Plant NORMS U.S. Nuclear Reaulatory Commission. Washin5 ton. D.C.

~

Mr. K. Jabbour, Licensing' Project-Manager - Hatch

'U.S. Nuclear Reaulatory Commission.~Reaion II Mr. S. . D. - Ebneter, Regional Administrator Mr. L. D. Wert,- Senior Resident' Inspector .__ Hatch

eevp-" - -

ENCLOSURE 1 PLANT HATCH-UNITS 1, 2 NRC DOCKETS 50-321, 50-366 OPERATING LICENSES DPR-57, NPF-5 REQUEST TO REVISE TECHNICAL SPECIFICATIONS:

TO REMOVF THE HAIN STEAM LINE RADIATION MONITOR REACTOR SCRAM AND GROUP ISOLATION FUNCTIONS BASIS FOR CHANGE REQUEST The proposed change elimina:as part of the current Units 1 and 2 primary containment isolation system (PCIS) Group 1 isolation, the reactor scram and the initiation of control room pressurization mode functions of the main steam line radiation monitors (MSLRMs). The revised Unit 1 and Unit 2 Technical Specifications (TS) remove: 1) the MSLRM isolation function for the main steam isolation valves (MSIVs) and main steam line drain valves, 2) the MSLRM scram function from the RPS instrumentation tables, and 3) the MSLRM initiation of the main control room environmental control (MCREC) system pressurization mode of operation. Also being changed are hydrogen injection and off-gas radiation monitor specifications. The following TS sections are affected:

1. Unit 1 S Tables 3.1-1, 4.1-1, 3.2-1, 3.2-8, 3.7-1 and section 3.12.
2. Unit 2 Tables 2.2.1-1; 3.3.1-1, 3.3.1-2, 3.3.2-1, 3.3.2-2, 3.3.6.7-1, 3.3.6.7-2, 4.3.1-1, 4.3.6.7-1, and section 3.7.2.
3. The associated Bases for both units.

The primary function of the MSLRM system is to provide early indication of gross fuel cladding failures. Four gamma-sensitive ion-chamber detectors located near the main steam lines (MSLs), just downstream of the outboard MSIVs, monitor MSL radiation levels. Upon detection of increasing MSL radiation levels, the MSLRMs alarm. As activity increases, the MSLRMs initiate a reactor scram and a Group 1 isolation at three times the normal, full-power background radiation levels in order to contain the fission products released from the fuel . (Group 1 valves consist of: 1) four inboard and four outboard MSIVs, 2) two MSL drain isolation valves, and

3) two reactor water sample i alation valves.)

The MSLRM trip is also used to de-energize and isolate the main condenser mechanical vacuum pump, trip and isolate the steam packing exhauster, and shift the control room ventilation to the pressurization mode. Specific to Unit 2 only, the trip also isolates the drywell-to-torus differential pressure valves.

In the proposed amendment, the four gamma-sensitive ion-chamber MSLRMs will remain in service. Only the MSIVs and MSL drain valves, the reactor scram, and pressurization mode functions are being removed. The other noted functions will remain in service.

HL-2006 003397 El-1

1 ENCLOSVRE 1 (Continued) i RE0 VEST TO REVISE TECHNICAL SPECIFICATIONS:

TO RLHOVE THE MAIN STEAM LINE RADIATION MONITOR RfACIDA_1 CRAM AND GROUP IS9B Il0N FUNCTIOU l :liminating the HSlV trip and reactor scram is recommended by the BWROG and the Plant Hatch Scram frequency Reduction Committees. Georgia Power 3 Company (GPC) believes removing the trips will significantly reduce the possibility of spurious scrams and engineered safety feature (ESF) actuations, in support of this goal, General Electric (GE) recently issued

NEDO-314AQ. " Safety Evaluation for Eliminating the Boiling Water Reactor
Main Steam isolation Valve Closure Function and Scram function of the Main Steam Line Radiation Monitor." In their Safety Evaluation Report dated hay 15, 1991, the NRC approved GE's conclusions presented in NED0-31400.

To ensure the applicability of the NEDO to Plant Hatch Units 1 and 2, GPC

! requested rJ to perform a trecif 4 review. CE confirmed NEDO-31400 applies i to Plant Hatch. GPC concurs witn the GE assessment, j No design basis accident (DBA) takes credit for a reactor scram attributed to high radiation in the MSLs. The only DBA which takes credit for an MSIV isolation is the control rod drop accident (CRDA). In NE00-314004 GE i

shows the occurrence of a CRDA, with the MSL high radiation isolation removed, results in offsite radiological exposures that are small fractions

. of 10 CFR 100 guidelines. Furthermore, the assumptions in NE00-31400 are i'

bounding for Plant Hatch Units 1 and 2, and the dose rates resulting from the CRDA for Hatch Units 1 and 2, with the elimination of the scram and MSIV isolation functions, are also small fractions of the 40 CFR 100 limits. These conclusions are supported in Enclosure 2.

~

The above analysis was performed for the CRDA described in the Unit 1 i

and 2 FSAR; this was the analysis Hatch was orioinalb iicensed under for CRDA. Hatch is presently licensed for CRDA, by NEDE-24Cil-P (GESTAR 11).

General Electric also verified, with GPC concurrence, that the assumptions and conclusions of NEDO-31400 are applicable to Hatch for the current licensing basis.

Whi e not snecifically addressed in GE's evaluation, eliminating the isc:ation o' the MSL drain valvet on MSL high radiation is also being proposed. Valves B21-F016 and B21-F019 drain to the main condenser, which is the same flow path as the MSlVs. The discharge of both the HSIV and MSL drain f')w paths is processed through the off-gas system.

The pressurization mode of tt Main centrol roem environmental control (MCREC) system protects main cuntrol room (MCR) operators in the event of certain DBAs. One of these events is the CRDA; accordingly, the pressurization mode automatically initiates on MSL high radiation..

Although removing thc trip was not addressed in the GE analysis, eliminating this initiation is justified because of the low probebility of occurrence of a CRDA, and also because the pressurization mode will automatically initiate on a high radiation signal at the MCR air intake.

HL-2006 003397 El-2

ENCLOSURE 1 (Continued)

REQUEST TO REVISE TECHNICAL SPECIFICATIONS: .

TO REMOVE THE MAIN STEAM LINE RADIATION MONITOR l

KAQJ.0_R SCRAM AND GR0])P_1.SQLAUfN FUNCIl0E Plant Hatch has adrquate controls in place such that, even with these trips removed, increased levels of radiation in the MSLs will be monitored and i controlled expeditiously. These controls &re generally in the form of l annuncietor response procedures and abnormal operating procedures. l

< In Ut, . t 1 TS Table 3.2-8 and Unit 2 TS Table 3.3.2-1, the hydrogen

, injection footnote associated with adjusting the MSLRM setpoints is being revised. Etten rattLthermal opwer is srutgr thAD_JLpercent, the existing note allows Chemistry personnel .to adjust the MSLRM setpoints within 24

hours prior to the start of hydropen injection The proposed revision deletes the 24-hour time requirement. The revisien also allows 72 hourr

! following a startup in which to make final aojustments to the trip

etpoints. However, when ratqLthnmal powJr is below 20.per_cfnt, the '

requirement to adjust the setpoint to normal radiation levels within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> following the completion of hydrogen injection is not changed by the

! proposed amendment. Retaining this requirement ensures the 3 times normal

setpoint will be intact to trip the mechanical vacuum pump at low power '

levels where the CRDA is applicable.

Action d. o' Unit 1 15 table 3.2-0 is also being revit.ed to reflect the installation of new NUMAC off-gas post trealment radiation monitor s. The existing note states that if one of the two post treatment monitors are inoperable, it must be tripped in the "dowr. scale" position. This is no longer applicable to the new instruments as no downscale" switch position exists. This specification is being changed to simply state that the monitors should be tripped.

In summary, GPC believes eliminating the noted MSLRM trip functions will result in a net benefit to plant safety by:

a. improving the availability of the main condenser for decay heat removal,
b. Eliminating inadvertent reactor scrams and challenges to safety systems.

HL-2006

! 003397 El-3

ENCLOSURE 2 PLANT HATCH UNITS 1 AND 2 NRC DOLKETS 50-32) AND 50-366 OPERAllNG LICENSES DPR-51 AND NPf-5 REQUEST TO REVISE TECHNICAL $PECIFICATIONS TO REMOVE THE MAIN STEAM LINE HIGH RADIAi!ON MONITOR MACIQJLifRAM AND_gBOUP ISOLATION FUEI1915 10 CFR 50.92 EVALUATION In 10 CFR 50.92(c), the NRC provided the following standards to be used in determining the existence of a significant hazards-consideration:

... a proposed amendment to an operating license for a facility i licen
ed under 50.21(b) or 50.22 or for a testing facility

{ involves no significant hetards consideration, if operation of the facility in accordance with the proposed amendment would nots (1) i Involve--a significantcincrease in the probability or consequences

of- an accident previously. evaluated; or _ _ (2) Create the j possibility. of- a new -or different kind of accident fr >
y
accident previously evaluated; or (3) Involve a signi' a t a reduction in a margin of safety.

!L Georgia Power Company has reviewed: this proposed license amendment r? quest 4

and determined its adoption- will not involve a significant hazards i consideration based on the following discussion.

pasis For Proposed No Sionificant Hazards Considerat'on 09terminat19.0:

i This change do9s not involve a significant hazards consideration, because it i- does not:

i

{- 1. Involve a significant increase in the probability or consequences of an accident previously evaluated. - .

The objective of the MSLRMs is to provide early indication.of gross- fuel failure. The monitors provide an alarm function, a scram function. and-an - isolation functien for the MSIVs. -The basis for the MSIV isolation i on a MSL high radiation _ signal is to reduce the' amount of fission-product release transported from the reactor vessel ta the condenser-during a CRDA. No DBA takes credit for a reactor scram resulting from a 'i

M high radiation ~ signal.. '

This proposed change removes some of the trip _ functions of the MSLRMs.

llo control rods, CRDs, rod coupling mechanisms, or any other equipment i

associated with the control rods or CRDs are affected by this change.

The- only modification-resulting from this change c is the removal of the l reactor scram, part'of the Group 1 isolation, and MCREC pressurization HL-2006 l _003397 E2-1 i-

i ENCLOSURE 2 (Continued)

! REQUEST TO REVISE TECHNICAL SPECIflCATIONS TO REMOVE THE MAIN STEAM LINE HIGH RADIATION HONITOR 4 REACTOR SCRAM AND GROUP ISOLATION FUNCTIONS

IQ_CFR Rg_I1AMA110N
mode initiation logic from the MSLRMs. These logic systems do not affect the operation of any equipment having the potential to cause a CRDA. Therefore, the pi bability of a CRDA is not increased or in any way affected by the prop 9 sed change.

In NED0-31400. GE included the safety evaluation (requested by the

] BWROG) addressing the removal of the scram and MSIV isolation. In the

, evaluation, GE concludes that eliminating the MSLRM trips results in

! exposures that_ are small fractions of 10 CfR 100 limits. GE also

a s s e s t.ed the applicability of NED0-31400 to Plant Hatch. Table 1 of

, this enclosure lists the assumptions presented in both NE00-31400 and the Hatch 1 FSAR. Table 2 lists the assumptions of NE00-31400 and the i Hatch 2 FSAR. Table 2 shows that two parameters of the Unit 2 CRDA analysis are not bounded by NEDO-31400 parameters:

I

a. JAq fraction of damannthel thalatlti - The difference in the i fraction of damaged fuel that melts is offset by the number of failed fuel rods. NED0-31400 assumts 850 rods fail; the Hatch 2 analysis assumes the failure of 770 rods. Also, the Unit 2 power per fuel rod is lower than that assumed . . the NEDO.

4

b. The_ iodine washout].plateout in the conitaitt - The smaller Unit 2 condenser leak rate and Chi /Q compensate for the higher iodine washout /plateout.

With the MSLRM scram and trip functions intact, the resulting Hatch l Unit 2 offsite doses-are 1.3 rem thyroid and 0.014 rem whole body. With the HSLRM trip functions eliminated and using the methods described in i

NED0-31400, the Unit 2 doses are 0.024 rem whole body and negligible for thyroid. The negligible thyroid dose is attributed to the iodine

retention in the charcoal beds of the off-gas system. The whole-body dose increase from 0.014 rem to 0.024 rem is not significant, especially when the thyroid dose is negligible, in quantitatively comparing the tws cases, GE used an " effective dose equivalent" (TDE), calculated i

using weighting factors obtained from 10-CFR 20.1003, so the doses could be expressed in terms of a whole-body dose. For the original case of the MSIVs closed, the ECE is 0.053 rem. With the removal of the MSIV trip, the EDE is just 0.024 rem, since the thyroid dose is negligible.

This supports the conclusion that eliminatirig the MSLRM scram and isolation functions will not significantly increase the consequences of a Unit 2 CRDA.

HL-2006 003397- E2-2

l

[NCLOSURE 2 (Continued)

REQUEST TO REVISE TECHNICAL SPECIFICATIONS TO REMOVE THE MAIN STEAM LINE HIGH RADIATION MONITOR RLAQ1QR_ SCRAM ANQJR0]P_1HMUR E1LNC110NS 10 CFR 50.92 EVALVATION 1

The offsite doses resulting from a Unit 1 CRDA with the MSLRM function 3

intact, are 3.2 rem thyroid and 0.6E-3 whole body. With the removal of the MSLRM trips, the doses are 0.024 rem whole body and negligible for thyroid. Again, iodine retention in the off-gas system accounts for the essentially zero thyroid dose. Although the whole-body dose increased, the increase is not significant when compared with 10 CfR 100 limits.

In using EDEs to onalyze a CRDA, with the MSIVs closed and open, the data are 0.1046 rem and 0.024 rem, respectively. Just as for Unit 2, the consequences of a CRDA for Unit I are not increased by eliminating the MSLRM scram and M91V isolation functions.

The above analysis was 3erformed for the CRDA described in the Unit I and 2 FSAR; this was tle analysis Hatch wat originally licensed under for CRDA. Ha+ch is presently licensed for CRDA by NEDE-240ll-P

, (GESTAR !!). General Electric also verified, with GPC concurrence, that l the assumptions and conclusions of NE00-31400 are applicable to Hatch for the current licensing basis.

While not specifically addressed in the GE evaluation, we also propose to eliminate the main steam line drain valves from the isolation logic.

These valves discharge to the main condenser as do the MSlVs; both paths acc therefore processed by the off-gas system. However, the drain I u hes discharge on one 3-inch line; the MSIVs exhaust to the condenser on four 24-inch lines. Thus, the exhaust from the drain path is minimai compared to the MSlVs.

! Of f-ga s system parameters, atmospheric dispersion factors, and final i dose rates are tabulated in Tables 3, 4, and b of this enclosure.

Remcving the automatic MSLRM high radiation initiation from the MCREC system pressurization mode of operation will not increase the consequences of the CRDA, because this mode of operation is also initiated on a high radiation signal at the MCR air intake, in addition, the abnormal operating procedure (A0P) for MSL high radiation will include directions to manually initiate the pressurization mode if a MSL high radiation condition is confirmed. The pressurization mode initiation on high radiation at the MCR air intake, together with the procedural guidance to manually- start the pressurization mode-upon i confirmation of an MSL high radiation condition, provides adequate l protection against control room inhabitants receiving excessive radiation exposure.

HL-2006 003397 E2-3 l

. -. -- . = - - - . _ - -- _- . _ _--

ENCLOSURE 2 (Continued)

REQUEST TO REVISE TECHNICAL SPECIFICATIONS TO REMOVE THE MAIN STEAM LINE HIGH RADIATION MONITOR REAC10R_ERAM AND GRRPl$1LAJ10N FUNClipM 10 CFR 50.92 EVALUATION Modifying the hydrogen water chemistry footnote does not increase the consequences of a CRDA, since hydrogen injection is not performed when rated thermal power is less than 20 percent. Thus, MSLRM setpoint adjustments will not be performed at low power levels when the CRDA is applicable.

Modifying action statement d. of Unit 1 TS table 3.2-8 does not increase the probability of occurrence or the consequences of any type accident.

The of f-gas monitors are not designed to prevent the occurrence of abnormal radiation releases, they merely monitor these releesos. The consequences of any radiological release events are not increased because -tH s change only clarifies a Technical Specification action st a te'nent to reflect the actual system configuration. lhe system will function and be operated as always.

2. Create the possibility of a new or different kind of accident from any accident previously evaluated.

l The function of a MSLRM trip is to detect abnormal fission product release and isolate the steam lines, thereby stopping the transport of fission products from the reactor to the main conderder. The monitors

do not perform a prevention function for any kind of accident. The i existence of a MSLRM trip does not prevent the occurrence of a fuel i failure event or any other type of event. Therefore, eliminating the

-trips neither increases nor decreases the possibility of occurrence of j any type event.

Removing part of the the Group 1 isolation trip, the reactor scram, and l the MCREC system pressurization mode initiation on MSL high radiation i from the respective logic systems will not affect the operatian of other 4 equipment or systems _ necessary for the prevention. or mitigation of accident!.

Revising the hydrogen water chemistry footnote does not change the operation of the hydrogen injection system, nor- does it change the operation of any other plant equipment or system. Therefore, no new-i accuent possibilities are created.

Modifying action statement d. does _not create the possibility of a different accident than one previously analyzed because the off- m HL-2006 003397 E2-4

ENCLOSURE 2 (Continued)

REQUEST TO REVISE TECHNICAL SPECIFICATIONS TO REMOVE THE MAIN STEAM LINE HIGH RADIATION MONITOR REACTOR SCRAM AND GROUP ISOLATION FUNCTIONS lQ CFR 50.92 EVAL 11AU_qN post treatment monitors tre not designed for the prevention of accidents, furthermore, this proposed change does not result in operation of the system outside its d1 sign bases.

3. Involve a significant reduction in a margin of safety.

The methodology described in NED0-31400, as applied to Plant Hatch, shows that, for the CRDA with the elimination of MSIV isolation, offsite radiological exposure limits are not significantly increased and remain well within 10 CfR 100 lime. s As discussed in the response to question no. 1 of this enclosure, offsite whole-body ('oses for Unit 2 increased from 0.014 to 0.024 rem as a result of eliminating-the MSLRM functions.

The Unit 1 offsite whole-body dose rates increased from 8.6E-3 to 0.024 rem. Although higher, these dose rates are still well within 10 CFR 100 limits. Furthermore, the thyroid dose becomes negligible, and as a result, the EDE is less for the case in which the MSLRM functions have been removed. The thyroid dose is negligible because NE00-31400 assumes the iodine is retained in the charcoal beds. Therefore, the margin to the 10 CFR 100 limits is not significantly reduced as a result of this change.

Adequate controls are presently in place, or will be implemented, to ensure significant increases in radiation levels in the MSLs are promptly addressed. For example, the MSLM high radiation alarm will remain in place, alarming at 1.5 times the normal full-power background.

At this point, annunciator response procedures (ARPs) and abnormal operating procedures (A0Ps) will provide guidance for verifying  :

automatic actions, checking secondary containment conditions, and noti fying plant personnel, in addition, A0Ps contain restrictions for venting the primary containment and-verifying the mechanical vacuum pump trip.

If area radiation monitor (ARM) readings exceed certain levels, entry

< into the secondary containment control section of the emergency operating procedures (E0Ps) will be rec;uired. Also, unexpectedly high ARM indications will necessitate initiating radiological procedures providing guidance to plant personnel for exiting the affected area, and monitoring and assessing their individual radhtion exposure.

A0P 34AS-0PS-062, " Closure of MSIVs on high Radiation," which includes many of.the above-listed actions, will be revised to include removal of the MSLRM scrt<. and part of the Group 1 isolation and pressurization HL-2006

  • 00330' E2-5 l

l

ENCLOS'llE 2 (Continued)

REQUEST TO REVISE TECHNICAL SPECIFICATIONS TO REMOVE THE MAIN STEAM LINE HIGH RADIATION MONITOR l EACTOR SCRAM AND GROUP !$9kALL0l f M CJ1 M$ ]

10 CFR 50.92 EVALUATION l mode trips. The entry condition will be changed to a high radiation alarm from the MSLRMs, as opposed to an MSIV closure on high radiation. ,

This A0P presently contains a requirement to sample the reactor coolant  !

following a Group 1 isolation caused by the MSLRMs. This guidance will be revised in require sampling of the coolant when the MSLRMs alarm high ar.d the high radiation condition has been confirmed on other monitors.

If the chemistry limits of TS 3.64F and 3/4.4.5 cannot be maintained for Units 1 and 2, respectively, the reactor will be shut down and the MSIVs closed. Off-gas-protreatment monitors, which alarm high at 1.5 times the normal radiation background levels, w'll be monitored upon receiet of a high MSL radiation alarm. This guidance'will be Poceduralized.

The MSLRM high alarm ARP contains actions for confirming the inlet to the off-gas system adsorbers is open and obtaining a sample of the pretreatment within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. The procedure also requires, through entry into a separate A0P, performance of a prompt offsite dose assessment. 4 If further increases in off-gas levels occur such that the high-high off-gas pretreatment annunciator alarms, reactor power must be reduced until the high-high alarm clears. This action is taker, to ensure compliance with the offsite gaseous effluent limits specified in TS 3.15.2.1 and 3.11.2.1 for Units 1 and 2, respectively.

All of the above procedural instructions and guidelines assure abnormally high radiation levels in the MSLs are monitored and controlled with minimal risk to plant workers and the public.

Relative to removing the pressurization mode initiation from the MSLRM high radiation signal, if a CRDA were to occur and the radiation levels arca d the MCR were to increase, the pressurization mode would automatically initiate due to high radiation levels at the air intake monitors. Also, the A0P will direct the operators to manually initiate the pressurization mode if a high radiation condition at the AiSLs is

, confirmed. Thus, sufficient redundancy exists to protect the MCR operators from excessive radiation exposure. The A0P does not presently include guidance to manually initiate the pressurization mode.

This will be included upon approval and prior to implementation of this amendment.

4 HL-2006 003397 E2-6

ENCLOSURE 2 (Continued)

REQUEST TO REVISE TECH'lICAL SPECIFICATIONS TO REMOVE THE MAIN STEAN LINE HIGH RADIATION MONITOR REAG1QR SCRAM AND_ GROUP ISOLATION FUNCTIONS 10 CFR 50.92 EVALUATION It should also be noted an NRC study concluded that the probability of occurrence of a CRDA which exceeds 260 calories per gram is approximately 10-12 events aer reactor year, with no rod pattern controls. At Plant. Hatch, t1ese controls are in place. Therefore, '

because sufficient redundancy exists in the form of ESFs and procedural I controls, and the probability of occurrence of a CRDA is low, removing -

the MCREC system pressurization mode automatic initiation on MSL hi0h radiation does not represent a significant reduction in the margin of '

safety.

The -hydrogen injection footnote is being revised to ease the burden on' I Chemistry personnel and- for - clarification. The 24-hour criterion for-  !

increased hydrogen and startups is being deleted, and a 72-hour criterion is being added to allow time to establish a steady-state power level and adequately determine tne adjusted setpoints. However, at '

power levels below-20 percent of rated thermal- power, hydrogen injection will not be performed, and within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of completing the hydrogen injection and prioi to dropping below 20-percent-rated thermal power, ,

the setpoints must be changed to the normal background levels. This "

requirement ensures that, at low power levels where the CRDA is applicable, setpoints will- be reset -to normal ' background levels.

Therefore, the margin of safety is not reduced.

Modifying action statement d. of Unit 1.TS table 3.2-8 does not dec' ease the margin of safety since no changes are being made_to the function and operation of the off-gas post treatment monitoring system. The monitors will be capable of monitoring and isolating the off-gas system as before. Also, the actions for one of the monitors being inoperable ,

remains essentially the same; the monitor must be placed in the tripped, i.e., " safe" condition.

!~

i-c j.-

p c

!. HL-2006

003397 E2-7 o

~ _ . ,_- -. . - _ _ _ _ - . - _ . . _ . - _ _ _ . _ . _ - , _ , , _ - . , - . . - - _ _ _

s i

El: CLOSURE 2 (Continued) [

TABLE 1 [

FSAR/NEDO VALUES FOR PLANT HATCH UNIT 1 CRDA FSAR SECTIONS PARAMETER NEDO-31409 11 5 AND 2.3  ;

Power level 0.12 MWt/ rod 0.14 MWt/ rod l No of failed fuel rods 850 770-i Core average fuel rod power l multiplier (peaking factor) 1.5 1.5 1 >

j Releace fractions for melt ,

(to coolant)

I Noble gases 100% 100%

lodines 50% 50%

j- Transport to steam t

~

Noble gases 100% 100%

lodines 10% 10%

Condenser activity remaining airborne i

Noble gases 100% 100%

lodines 10% 50%

i Condenser leak rate 1%/ day 0.5%/ day.  !

Chi /0 for release at ground level,s/m3* 2.5E-3 1.4E-4

  • For Unit 1, Chi /Q is calculated with Paso'4111 F,1 m/s wind speed, plume centerline, with a maximum dilution factor of 1/3, per FSAR.

I HL-2006 003397 E2-8 l

1, , , , , _ . . . .._u... . , _ . _ _ _ _ - , _ . _ . _ _ _ , _ , . . . _ _ , _ - .. . .- . . ~ - _ _ . .

i i

l ENCLOSURE 2 (Continued) j TABLE 2 FSAR/NEDO VALUES FOR PLANT HATCH UNIT 2 CRDA

FSAR SECTIONS '

i PARAMETER JLE00-31400 15 1.38 & 11.3.2 s

j Power level 0.12 MWt/ rod 0.11 MWt/roo 8

No. of faile; r u el rods 850 770 i

Mass fraction of fuel l > melt temperature 0.0077 0.0091 i Core average fuel rod power

, multiplier (peaking facter) 1.5 1.5 ,

R(lease fractions for melt (to coolant)

Noble gases 100% 100%

Iodines 50% 50%

! Release fractions for nonmelt I

(to coolant)

Noble gascs 10% 10%

lodines 10% 10%

l Multiplier of rated thermal power 1.05 4.00 4

Transport to steam l Noble gases 100% 100%

lodines 10% 10%

{ Condenser activity remaining

! airborne Noble gases 100% 100%

lodines 10% 50%-

Condenser leak rate 1%/ day 0.'.%/ day 4

Cht/Q for release at ground j level, s/m3 2.5E-3 3.lE-4 b

4 HL-2006 003397 E2-9

. . . - - _ _ _ - _= . . . . _ _ - - - _ . . - - . - - _ _ . . . . - - ... . . - . . . -

1 1

-)

l ENCLOSURE 2 (Continued)

I TABLE 3

PLANT HATCH UNIT 1 0FF-GAS SYSTEM l j l l FSAR SECTIONS 4 PARAMETER MLQO-31400 2.3 and E.4 Chi /Q for main stack j release point 3,0E-4 1.7E-6 j

Holdup time in off-gas i treatment system

} Kryptons family of. curves 9.0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br />

! Xenons family of curves 6.8 days i

i i

1 s

j -

i 1

i f

T i HL-2006 003397 E2-10

, _ .. _ x _;. . . . . _ . _ . . _ _ .. . . . _ . ~ . - - . . . _ _ . _ . . _ _

. - . . - . - .= ._-

l l

l ENCLOSURE 2 (Continued) i

TABLE 4 1

PLANT HATCH UNIT 2 Off-GAS SYSTEM 1

1 FSAR SECTIONS i PARAMETER NED0-31400 15.1.38 & 11.3.2 i

j Chi /Q for main stack

release point 3.0E-4 1.7E-6 7 Holdup time in off-gas i treatment system l Kryptons family of curves 9.0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> i Xenons f atnily of r.urves 6.8 days

),

3 I

J t

a 4

I 3

l l

. l

, i

  • l 4 ,

i HL-2006  !

-003397 E2-11 i

ENCLOSURE 2 (Continued)

TABLE 5 DOSE RESULTS FOR PLANT HATCH UNITS 1 AND 2 (rem)

MSIV Functions Present (fSAR Methods)

Thyroid Whole Body [Q(

Unit 1 3.2 8.6E-3 0.1046 Unit 2 1.3 0.014 0.053 NE00-31400 4.3 0.31 0.439 (resulting doses when conservative parameters in topical report are used) i MSly functions Removed

(NED0-31400 methods)

Thyroid Whole Body [Q{

Unit 1 0.0 0.024 0.024 Unit 2 0.0 0.024 0.024 i

i j

i f

I i

HL-2006 003397 E2-12 f l

,

Retrieved from "https://kanterella.com/w/index.php?title=HL-2006,_Application_for_Amends_to_Licenses_DPR-57_%26_NPF-5,revising_TS_to_Remove_Main_Steam_Line_Radiation_Monitor_Reactor_Scram_%26_Group_Isolation_Functions,Per_BWROG_Topical_Rept_NEDO-31400,_SE_for_Eliminating_BWR_MSIV_Closure..&oldid=3475160"