Text

Response to Request for Additional Information Regarding License Amendment Request for Emergency Action Level Scheme Change
	ML18351A052
Person / Time
Site:	Harris
Issue date:	12/17/2018
From:	Hamilton T; Duke Energy Progress
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	RA-18-0248
	Download: ML18351A052 (41)
	v • d • e

Tanya M. Hamilton Vice President Harris Nuclear Plant 5413 Shearon Harris Rd New Hill, NC 27562-9300 10 CFR 50.90 December 17, 2018 Serial: RA-18-0248 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Shearon Harris Nuclear Power Plant, Unit 1 Docket No. 50-400 Renewed License No. NPF-63

Subject:

Response to Request for Additional Information Regarding License Amendment Request for Emergency Action Level Scheme Change Ladies and Gentlemen:

By application dated August 13, 2018 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML18226A022), Duke Energy Progress, LLC (Duke Energy),

requested approval for an emergency action level (EAL) scheme change for Shearon Harris Nuclear Power Plant, Unit 1 (HNP). The Nuclear Regulatory Commission (NRC) staff reviewed the request and determined that additional information is needed to complete their review. Duke Energy received a request for additional information (RAI) from the NRC staff through electronic mail on November 19, 2018 (ADAMS Accession No. ML18332A439), with a required response date of December 27, 2018. to this letter provides Duke Energys response to the RAI. The proposed changes to the impacted pages of the EAL Technical Basis Document provided in the application dated August 13, 2018, were updated to incorporate changes in response to the RAI. Enclosure 2 provides the clean version of the HNP EAL Technical Bases Document impacted pages.

Enclosures 3 provides the markup version of the HNP EAL Technical Bases Document impacted pages. Enclosure 4 provides a markup version of the HNP EAL Wallcharts for the proposed changes.

In accordance with 10 CFR 50.91(b), HNP is providing the state of North Carolina with a copy of this response.

This letter does not contain any regulatory commitments.

Should you have any questions regarding this submittal, please contact Arthur Zaremba at (980) 373-2062.

U.S. Nuclear Regulatory Commission Serial RA-18-0248 I declare under penalty of perjury that the foregoing is true and correct. Executed on December I 1 1 2018.

Sincerely, Tanya M. Hamilton

Enclosures:

1. Response to Request for Additional Information Page 2 of 2

2. Proposed Harris Nuclear Plant Emergency Action Level Technical Bases Document Changes! EP-EAL (Clean)

3. Proposed Harris Nuclear Plant Emergency Action Level Technical Bases Document Changes, EP-EAL (Markup)

4. Proposed Harris Nuclear Plant Emergency Action Level Wallchart Changes (Markup) cc:

J. Zeiler, NRC Sr. Resident Inspector, HNP W. L. Cox, 111 1 Section Chief, N.C. DHSR M. Barillas, NRC Project Manager, HNP NRC Regional Administrator, Region II

U.S. Nuclear Regulatory Commission Page 2 of 2 Serial RA-18-0248 I declare under penalty of perjury that the foregoing is true and correct. Executed on December, 2018.

Sincerely, Tanya M. Hamilton

Enclosures:

1.

Response to Request for Additional Information 2.

Proposed Harris Nuclear Plant Emergency Action Level Technical Bases Document Changes, EP-EAL (Clean) 3.

Proposed Harris Nuclear Plant Emergency Action Level Technical Bases Document Changes, EP-EAL (Markup) 4.

Proposed Harris Nuclear Plant Emergency Action Level Wallchart Changes (Markup) cc:

J. Zeiler, NRC Sr. Resident Inspector, HNP W. L. Cox, III, Section Chief, N.C. DHSR M. Barillas, NRC Project Manager, HNP NRC Regional Administrator, Region II

U.S. Nuclear Regulatory Commission Serial RA-18-0248, Enclosure 1 SERIAL RA-18-0248 ENCLOSURE 1 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION SHEARON HARRIS NUCLEAR POWER PLANT, UNIT 1 DOCKET NO. 50-400 RENEWED LICENSE NUMBER NPF-63

U.S. Nuclear Regulatory Commission Page 1 of 2 Serial RA-18-0248, Enclosure 1 By application dated August 13, 2018 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML18226A022), Duke Energy Progress, LLC (Duke Energy),

requested approval for an emergency action level (EAL) scheme change for Shearon Harris Nuclear Power Plant, Unit 1 (HNP). The Nuclear Regulatory Commission (NRC) staff reviewed the request and determined that additional information is needed to complete their review. Duke Energy received a request for additional information (RAI) from the NRC staff through electronic mail on November 19, 2018 (ADAMS Accession No. ML18332A439), with a required response date of December 27, 2018.

Duke Energy provides the following response to the RAI regarding the license amendment request. The proposed changes to the impacted pages of the EAL Technical Basis Document provided in the application dated August 13, 2018, were updated to incorporate changes in response to the RAI. Enclosure 2 provides the clean version of the HNP EAL Technical Bases Document impacted pages. Enclosures 3 provides the markup version of the HNP EAL Technical Bases Document impacted pages. Enclosure 4 provides a markup version of the HNP EAL Wallcharts for the proposed changes. There are no changes to the information provided in the significant hazards consideration within the application submitted on August 13, 2018, because of this RAI response.

HNP RAI-1:

Emergency action level (EAL) threshold levels for CS1.3 and CG1.2 [CS1 and CG1] are applicable in Modes 5 and 6. However, page 5 of Enclosure 5, Calculation for Radiation Monitor Readings for Core Uncovery during Refueling, provides that the CG1.2 radiation monitor threshold value is predicated on the loss of water above the core during refueling shutdown with the reactor vessel head removed. EAL CS1.3 uses the same radiation value as EAL CG1.2. No radiation monitor threshold values were provided for Modes 5 or 6 with the head installed.

a. Although Enclosure 5 provides that the radiation monitor threshold is predicated on a loss of water with the reactor vessel head removed, there was no note or other guidance provided in the threshold values for EALs CS1.3 or CG1.2, which indicated that the threshold value is based on the reactor vessel head being removed. Please explain how an inaccurate or delayed classification would not occur if EALs CS1.3 and CG1.2 do not clearly indicate that the threshold values are based on the reactor vessel head being removed.

b. The staff could not determine if an accurate containment radiation threshold value, corresponding to reactor vessel level being approximately at the top of active fuel, could be determined with the reactor vessel head installed. Please explain why a containment radiation level threshold value indicating water level at the top of active fuel was not provided with the reactor vessel head installed.

HNP Response:

a. A change has been made to the EAL basis for EALs CS1.3 and CG1.2 to provide clarification regarding the calculation assumptions used to establish the radiation monitor threshold value. The following statement has been added to EAL basis for EALs CS1.3 and CG1.2, as shown in Enclosures 2 and 3:

A calculation shows that if these radiation monitors reach and exceed 2.6E+04 mR/hr when the reactor vessel head is removed, with RCS [reactor coolant system] water level indication

U.S. Nuclear Regulatory Commission Page 2 of 2 Serial RA-18-0248, Enclosure 1 unavailable for greater than 30 minutes, then a loss of inventory with potential to uncover the core is likely to have occurred.

b. The other initiating conditions of EALs CS1.3 and CG1.2 for core uncovery, which are an unplanned increase in any Table C-1 sump or tank of sufficient magnitude to indicate core uncovery or erratic source range monitor indication, remain available to provide the basis for the declaration of EALs CS1.3 and CG1.2 when the plant is in Modes 5 or 6 with the reactor vessel head installed. Therefore, a containment radiation level threshold value indicating water level at the top of active fuel with the reactor vessel head installed was not provided for EALs CS1.3 and CG1.2.

HNP RAI-2:

The Table F-1 Fission Product Barrier Threshold Matrix for Containment Radiation provides the radiation monitors that should be used to assess the fission product barriers. As proposed, two separate types of monitors with different ranges will be used to assess containment radiation.

The associated values to assess Table F-1 threshold values for containment radiation are provided on Table F-2, Containment Radiation. Since Table F-2 does not include which radiation monitors should be used, and uses both milli-rem and rem (which is only provided in the title block), there is a potential for either a delayed or inaccurate classification. Please explain how the proposed Table F-1 and F-2 will not cause either a potential delay or an inaccurate classification of fission product barriers based on containment radiation values or revise accordingly.

HNP Response:

A change has been made to Table F-2 that includes the radiation monitor information and the units of measurement for the radiation monitor values shown in the table. The units of measurement in the Table F-2 are consistent with the units of measurement indicated by the radiation monitors. This change is shown in Enclosures 2, 3, and 4.

U.S. Nuclear Regulatory Commission Serial RA-18-0248, Enclosure 2 SERIAL RA-18-0248 ENCLOSURE 2 PROPOSED HARRIS NUCLEAR PLANT EMERGENCY ACTION LEVEL TECHNICAL BASES DOCUMENT CHANGES, EP-EAL (CLEAN)

SHEARON HARRIS NUCLEAR POWER PLANT, UNIT 1 DOCKET NO. 50-400 RENEWED LICENSE NUMBER NPF-63

ATTACHMENT 1 EAL Bases EP-EAL Rev. XXX DRAFT Page 70 of 220 Category:

C - Cold Shutdown / Refueling System Malfunction Subcategory:

1 - RCS Level Initiating Condition: Loss of RCS inventory affecting core decay heat removal capability EAL:

CS1.3 Site Area Emergency RCS water level cannot be monitored for 30 min. (Note 1)

AND Core uncovery is indicated by any of the following:

UNPLANNED increase in any Table C-1 sump or tank of sufficient magnitude to indicate core uncovery

A Containment Ventilation Isolation Radiation Monitor > 2.6E+04 mR/hr (RM-1CR-3561A-SA, RM-1CR-3561B-SB, RM-1CR-3561C-SA, or RM-1CR-3561D-SB)

Erratic source range monitor indication Note 1:

The Emergency Coordinator should declare the event promptly upon determining that time limit has been exceeded, or will likely be exceeded.

Table C-1 Sumps / Tanks

Containment sumps

PRT

RCDT

CCW surge tank

RAB sumps

RWST

RMWST

Recycle Holdup Tank Mode Applicability:

5 - Cold Shutdown, 6 - Refueling Definition(s):

UNISOLABLE - An open or breached system line that cannot be isolated, remotely or locally.

UNPLANNED - A parameter change or an event that is not 1) the result of an intended evolution or 2) an expected plant response to a transient. The cause of the parameter change or event may be known or unknown.

ATTACHMENT 1 EAL Bases EP-EAL Rev. XXX DRAFT Page 71 of 220 Basis:

In this EAL, all RCS water level indication would be unavailable for greater than 30 minutes, and the RCS inventory loss must be detected by indirect leakage indications. Sump level increases must be evaluated against other potential sources of leakage. If the make-up rate to the RCS unexplainably rises above the pre-established rate, a loss of RCS inventory may be occurring even if the source of the leakage cannot be immediately identified. Sumps and tanks where RCS leakage may accumulate are listed in listed in Table C-1(ref. 1, 2).

In the Refueling Mode, as water level in the reactor vessel lowers, the dose rate above the core will increase. The dose rate due to this loss of water shielding from the reactor cavity will result in indications on the Containment Ventilation Isolation (CVI) area radiation monitors. A calculation (ref. 4) shows that if these radiation monitors reach and exceed 2.6E+04 mR/hr when the reactor vessel head is removed, with RCS water level indication unavailable for greater than 30 minutes, then a loss of inventory with potential to uncover the core is likely to have occurred.

Post-TMI accident studies indicated that the installed PWR nuclear instrumentation will operate erratically when the core is uncovered and that this should be used as a tool for making such determinations.

This IC addresses a significant and prolonged loss of RCS inventory control and makeup capability leading to IMMINENT fuel damage. The lost inventory may be due to a RCS component failure, a loss of configuration control or prolonged boiling of reactor coolant.

These conditions entail major failures of plant functions needed for protection of the public and thus warrant a Site Area Emergency declaration.

Following an extended loss of core decay heat removal and inventory makeup, decay heat will cause reactor coolant boiling and a further reduction in reactor vessel level. If RCS level cannot be restored, fuel damage is probable.

The 30-minute criterion is tied to a readily recognizable event start time (i.e., the total loss of ability to monitor level), and allows sufficient time to monitor, assess and correlate reactor and plant conditions to determine if core uncovery has actually occurred (i.e., to account for various accident progression and instrumentation uncertainties). It also allows sufficient time for performance of actions to terminate leakage, recover inventory control/makeup equipment and/or restore level monitoring.

The inability to monitor RCS level may be caused by instrumentation and/or power failures, or water level dropping below the range of available instrumentation. If water level cannot be monitored, operators may determine that an inventory loss is occurring by observing changes in sump and/or tank levels. Sump and/or tank level changes must be evaluated against other potential sources of water flow to ensure they are indicative of leakage from the RCS.

EAL values should be determined with a margin sufficient to ensure that an accurate monitor reading is available. For example, an EAL monitor reading might be set at 90% to 95% of the highest accurate monitor reading.

ATTACHMENT 1 EAL Bases EP-EAL Rev. XXX DRAFT Page 72 of 220 A single calculated radiation monitor reading does not represent core uncovery for all event scenarios due to multiple variables that can affect the source term (i.e., number of fuel assemblies in the core, fuel burn up in each assembly, and time after shutdown). Therefore, consideration has been given so that the threshold value of > 2.6E+04 mR/hr on the CVI radiation monitors will be low enough to be a valid indication of fuel uncovery, but high enough so that inadvertent classifications are not caused by maintenance events or other conditions that may increase radiation levels without a coincident loss of reactor vessel water level (ref. 4).

HNP utilizes CVI area radiation monitors RM-1CR-3561A-SA, 1RM-1CR-3561B-SB, RM-1CR-3561C-SA, and RM-1CR-3561D-SB for evaluating conditions in containment. The sensitivity and location of these monitors allows them to detect significant changes in the loss of water shielding from the reactor cavity, which can be used to detect core uncovery.

This EAL addresses concerns raised by Generic Letter 88-17, Loss of Decay Heat Removal; SECY 91-283, Evaluation of Shutdown and Low Power Risk Issues; NUREG-1449, Shutdown and Low-Power Operation at Commercial Nuclear Power Plants in the United States; and NUMARC 91-06, Guidelines for Industry Actions to Assess Shutdown Management.

Escalation of the emergency classification level would be via IC CG1 or RG1.

HNP Basis Reference(s):

1. GP-001, Reactor Coolant System Fill and Vent Mode 5

2. GP-008, Draining the Reactor Coolant System

3. GP-009, Refueling Cavity Fill, Refueling and Drain of the Refueling Cavity Modes 5-6-5

4. CSD-EP-HNP-0101-06, Radiation Monitor Readings for Core Uncovery during Refueling

5. NEI 99-01 CS1

ATTACHMENT 1 EAL Bases EP-EAL Rev. XXX DRAFT Page 76 of 220 Category:

C - Cold Shutdown / Refueling System Malfunction Subcategory:

1 - RCS Level Initiating Condition: Loss of RCS inventory affecting fuel clad integrity with containment challenged EAL:

CG1.2 General Emergency RCS level cannot be monitored for 30 min. (Note 1)

AND Core uncovery is indicated by any of the following:

UNPLANNED increase in any Table C-1 sump or tank of sufficient magnitude to indicate core uncovery

A Containment Ventilation Isolation Radiation Monitor > 2.6E+04 mR/hr (RM-1CR-3561A-SA, RM-1CR-3561B-SB, RM-1CR-3561C-SA, or RM-1CR-3561D-SB)

Erratic source range monitor indication AND Any Containment Challenge indication, Table C-2 Note 1:

The Emergency Coordinator should declare the event promptly upon determining that time limit has been exceeded, or will likely be exceeded.

Note 6:

If CONTAINMENT CLOSURE is re-established prior to exceeding the 30-minute time limit, declaration of a General Emergency is not required.

Table C-1 Sumps / Tanks

Containment sumps

PRT

RCDT

CCW surge tank

RAB sumps

RWST

RMWST

Recycle Holdup Tank Table C-2 Containment Challenge Indications

CONTAINMENT CLOSURE not established (Note 6)

Containment hydrogen concentration 4%

UNPLANNED rise in Containment pressure

ATTACHMENT 1 EAL Bases EP-EAL Rev. XXX DRAFT Page 77 of 220 Mode Applicability:

5 - Cold Shutdown, 6 - Refueling Definition(s):

CONTAINMENT CLOSURE - The procedurally defined actions taken to secure containment and its associated structures, systems, and components as a functional barrier to fission product release under shutdown conditions. As applied to HNP, Containment Closure is established when containment penetration closure is established in accordance with Technical Specifications 3/4.9.4.

UNISOLABLE - An open or breached system line that cannot be isolated, remotely or locally.

UNPLANNED - A parameter change or an event that is not 1) the result of an intended evolution or 2) an expected plant response to a transient. The cause of the parameter change or event may be known or unknown.

Basis:

In this EAL, all RCS water level indication would be unavailable for greater than 30 minutes, and the RCS inventory loss must be detected by indirect leakage indications. Sump level increases must be evaluated against other potential sources of leakage. If the make-up rate to the RCS unexplainably rises above the pre-established rate, a loss of RCS inventory may be occurring even if the source of the leakage cannot be immediately identified. Sumps and tanks where RCS leakage may accumulate are listed in listed in Table C-1 (ref. 1, 2).

In the Refueling Mode, as water level in the reactor vessel lowers, the dose rate above the core will increase. The dose rate due to core uncover will result in indications on the Containment Ventilation Isolation (CVI) area radiation monitors. A calculation (ref. 4) shows that if these radiation monitors reach and exceed 2.6E+04 mR/hr when the reactor vessel head is removed, with RCS water level indication unavailable for greater than 30 minutes, then a loss of inventory with potential to uncover the core is likely to have occurred.

Post-TMI accident studies indicated that the installed PWR nuclear instrumentation will operate erratically when the core is uncovered and that this should be used as a tool for making such determinations.

ATTACHMENT 1 EAL Bases EP-EAL Rev. XXX DRAFT Page 78 of 220 Three conditions are associated with a challenge to containment integrity:

CONTAINMENT CLOSURE is not established.

In the early stages of a core uncovery event, it is unlikely that hydrogen buildup due to a core uncovery could result in an explosive mixture of dissolved gases in the containment. However, containment monitoring and/or sampling should be performed to verify this assumption and a General Emergency declared if it is determined that an explosive mixture exists. An explosive mixture can be formed when hydrogen gas concentration in the containment atmosphere is greater than 4% by volume in the presence of oxygen.

Any unplanned increase in containment pressure in the Cold Shutdown or Refueling mode indicates a potential loss of containment closure capability. Unplanned containment pressure increases indicates containment closure cannot be assured and the containment cannot be relied upon as a barrier to fission product release.

This IC addresses the inability to restore and maintain reactor vessel level above the top of active fuel with containment challenged. This condition represents actual or IMMINENT substantial core degradation or melting with potential for loss of containment integrity.

Releases can be reasonably expected to exceed EPA PAG exposure levels offsite for more than the immediate site area.

Following an extended loss of core decay heat removal and inventory makeup, decay heat will cause reactor coolant boiling and a further reduction in reactor vessel level. If RCS level cannot be restored, fuel damage is probable.

With CONTAINMENT CLOSURE not established, there is a high potential for a direct and unmonitored release of radioactivity to the environment. If CONTAINMENT CLOSURE is re-established prior to exceeding the 30-minute time limit, then declaration of a General Emergency is not required.

The existence of an explosive mixture means, at a minimum, that the containment atmospheric hydrogen concentration is sufficient to support a hydrogen burn (i.e., at the lower deflagration limit). A hydrogen burn will raise containment pressure and could result in collateral equipment damage leading to a loss of containment integrity. It therefore represents a challenge to Containment integrity.

In the early stages of a core uncovery event, it is unlikely that hydrogen buildup due to a core uncovery could result in an explosive gas mixture in containment. If all installed hydrogen gas monitors are out-of-service during an event leading to fuel cladding damage, it may not be possible to obtain a containment hydrogen gas concentration reading as ambient conditions within the containment will preclude personnel access. During periods when installed containment hydrogen gas monitors are out-of-service, operators may use the other listed indications to assess whether or not containment is challenged.

ATTACHMENT 1 EAL Bases EP-EAL Rev. XXX DRAFT Page 79 of 220 The 30-minute criterion is tied to a readily recognizable event start time (i.e., the total loss of ability to monitor level), and allows sufficient time to monitor, assess and correlate reactor and plant conditions to determine if core uncovery has actually occurred (i.e., to account for various accident progression and instrumentation uncertainties). It also allows sufficient time for performance of actions to terminate leakage, recover inventory control/makeup equipment and/or restore level monitoring.

The inability to monitor RCS level may be caused by instrumentation and/or power failures, or water level dropping below the range of available instrumentation. If water level cannot be monitored, operators may determine that an inventory loss is occurring by observing changes in sump and/or tank levels. Sump and/or tank level changes must be evaluated against other potential sources of water flow to ensure they are indicative of leakage from the RCS.

EAL values should be determined with a margin sufficient to ensure that an accurate monitor reading is available. For example, an EAL monitor reading might be set at 90% to 95% of the highest accurate monitor reading.

A single calculated radiation monitor reading does not represent core uncovery for all event scenarios due to multiple variables that can affect the source term (i.e., number of fuel assemblies in the core, fuel burn up in each assembly, and time after shutdown). Therefore, consideration has been given so that the threshold value of > 2.6E+04 mR/hr on the CVI radiation monitors will be low enough to be a valid indication of fuel uncovery, but high enough so that inadvertent classifications are not caused by maintenance events or other conditions that may increase radiation levels without a coincident loss of reactor vessel water level (ref. 4).

HNP utilizes CVI area radiation monitors RM-1CR-3561A-SA, 1RM-1CR-3561B-SB, RM-1CR-3561C-SA, and RM-1CR-3561D-SB for evaluating conditions in containment. The sensitivity and location of these monitors allows them to detect significant changes in the loss of water shielding from the reactor cavity, which can be used to detect core uncovery.

This EAL addresses concerns raised by Generic Letter 88-17, Loss of Decay Heat Removal; SECY 91-283, Evaluation of Shutdown and Low Power Risk Issues; NUREG-1449, Shutdown and Low-Power Operation at Commercial Nuclear Power Plants in the United States; and NUMARC 91-06, Guidelines for Industry Actions to Assess Shutdown Management.

HNP Basis Reference(s):

1. GP-001, Reactor Coolant System Fill and Vent Mode 5

2. GP-008, Draining the Reactor Coolant System

3. GP-009, Refueling Cavity Fill, Refueling and Drain of the Refueling Cavity Modes 5-6-5

4. CSD-EP-HNP-0101-06, Radiation Monitor Readings for Core Uncovery during Refueling

5. NEI 99-01 CG1

ATTACHMENT 2 Fission Product Barrier Loss/Potential Loss Matrix and Bases EP-EAL Rev. XXX DRAFT Page 177 of 220 Table F-1 Fission Product Barrier Threshold Matrix Fuel Clad (FC) Barrier Reactor Coolant System (RCS) Barrier Containment (CNMT) Barrier Category Loss Potential Loss Loss Potential Loss Loss Potential Loss A

RCS or SG Tube Leakage None None

1. An automatic or manual ECCS (SI) actuation required by EITHER:

UNISOLABLE RCS leakage

SG tube RUPTURE

1. CSFST Integrity-RED Path entry conditions met

1. A leaking or RUPTURED SG is FAULTED outside of containment None B

Inadequate Heat Removal

1. CSFST Core Cooling-RED Path entry conditions met

1. CSFST Core Cooling-ORANGE PATH entry conditions met

2. CSFST Heat Sink-RED Path entry conditions met AND Heat sink is required None

1. CSFST Heat Sink-RED Path entry conditions met AND Heat sink is required None

1.

CSFST Core Cooling-RED Path entry conditions met AND Restoration procedures not effective within 15 min. (Note 1)

C CNMT Radiation

/ RCS Activity

1. (RM-1CR-3589SA or RM-1CR-3590SB) > Table F-2 Column FC Barrier Loss

2. Dose equivalent I-131 coolant activity > 300 µCi/gm None

1. (RM-1CR-3561A-SA, RM-1CR-3561B-SB, RM-1CR-3561C-SA, or RM-1CR-3561D-SB) > Table F-2 Column RCS Barrier Loss None None

1. (RM-1CR-3589SA or RM-1CR-3590SB) > Table F-2 Column CNMT Potential Loss D

CNMT Integrity or Bypass None None None None

1. Containment isolation is required AND EITHER:

Containment integrity has been lost based on Emergency Coordinator judgment

UNISOLABLE pathway from Containment to the environment exists

2. Indications of RCS leakage outside of containment

1.

CSFST Containment-RED Path entry conditions met

2. Containment hydrogen concentration

> 4%

3. Containment pressure > 10 psig with < one full train of depressurization equipment operating (one CNMT spray pump and two CNMT fan coolers) per design for 15 min.

(Note 1)

E EC Judgment

1. Any condition in the opinion of the Emergency Coordinator that indicates loss of the fuel clad barrier

1.

Any condition in the opinion of the Emergency Coordinator that indicates potential loss of the fuel clad barrier

1.

Any condition in the opinion of the Emergency Coordinator that indicates loss of the RCS barrier

1.

Any condition in the opinion of the Emergency Coordinator that indicates potential loss of the RCS barrier

1.

Any condition in the opinion of the Emergency Coordinator that indicates loss of the containment barrier

1.

Any condition in the opinion of the Emergency Coordinator that indicates potential loss of the containment barrier Table F-2 Containment Radiation Time After S/D FC Barrier Loss:

RM-1CR-3589SA or RM-1CR-3590SB RCS Barrier Loss:

RM-1CR-3561A-SA, RM-1CR-3561B-SB, RM-1CR-3561C-SA, or RM-1CR-3561D-SB CNMT Potential Loss:

RM-1CR-3589SA or RM-1CR-3590SB 0 - 1 hr 130 R/hr 1.37E+03 mR/hr 2360 R/hr 1 - 2 hrs 110 R/hr 1.12E+03 mR/hr 2000 R/hr 2 - 8 hrs 70 R/hr 6.35E+02 mR/hr 1300 R/hr

> 8 hrs 21 R/hr 1.37E+02 mR/hr 390 R/hr

ATTACHMENT 2 Fission Product Barrier Loss/Potential Loss Matrix and Bases EP-EAL Rev. XXX DRAFT Page 183 of 220 Barrier:

Fuel Clad Category:

C. CNMT Radiation / RCS Activity Degradation Threat: Loss Threshold:

1. RM-1CR-3589SA or RM-1CR-3590SB > Table F-2, Column FC Barrier Loss Table F-2 Containment Radiation Time After S/D FC Barrier Loss:

RM-1CR-3589SA or RM-1CR-3590SB RCS Barrier Loss:

RM-1CR-3561A-SA, RM-1CR-3561B-SB, RM-1CR-3561C-SA, or RM-1CR-3561D-SB CNMT Potential Loss:

RM-1CR-3589SA or RM-1CR-3590SB 0 - 1 hr 130 R/hr 1.37E+03 mR/hr 2360 R/hr 1 - 2 hrs 110 R/hr 1.12E+03 mR/hr 2000 R/hr 2 - 8 hrs 70 R/hr 6.35E+02 mR/hr 1300 R/hr

> 8 hrs 21 R/hr 1.37E+02 mR/hr 390 R/hr Definition(s):

None Basis:

Containment radiation monitor readings greater than Table F-2, FC Barrier Loss indicate the release of reactor coolant, with elevated activity indicative of fuel damage, into the Containment. The radiation monitor reading is derived assuming the instantaneous release and dispersal of the reactor coolant noble gas and iodine inventory associated with a concentration of 300 µCi/cc dose equivalent I-131 into the Containment atmosphere (ref. 1).

Reactor coolant concentrations of this magnitude are several times larger than the maximum concentrations (including iodine spiking) allowed within technical specifications and are therefore indicative of fuel damage.

RM-1CR-3589SA and RM-1CR-3590SB are the Containment High Range Monitors that provide indication of radiation levels in Containment during and after postulated accidents (ref. 2).

Since this condition indicates that a significant amount of fuel clad damage has occurred, it represents a loss of the Fuel Clad Barrier.

ATTACHMENT 2 Fission Product Barrier Loss/Potential Loss Matrix and Bases EP-EAL Rev. XXX DRAFT Page 184 of 220 The radiation monitor reading in this threshold is higher than that specified for RCS Barrier Loss threshold C.1 since it indicates a loss of both the Fuel Clad Barrier and the RCS Barrier.

Note that a combination of the two monitor readings appropriately escalates the ECL to a Site Area Emergency.

HNP Basis Reference(s):

1. EP-EALCALC-HNP-1701, Containment Radiation EAL Threshold Values

2. DBD-304, Radiation Monitoring System and Gross Failed Fuel Monitor

3. NEI 99-01 CNMT Radiation / RCS Activity Fuel Clad Loss 3.A

ATTACHMENT 2 Fission Product Barrier Loss/Potential Loss Matrix and Bases EP-EAL Rev. XXX DRAFT Page 195 of 220 Barrier:

Reactor Coolant System Category:

C. CNMT Radiation/ RCS Activity Degradation Threat: Loss Threshold:

1. A Containment Ventilation Isolation Radiation Monitor (RM-1CR-3561A-SA, RM-1CR-3561B-SB, RM-1CR-3561C-SA, or RM-1CR-3561D-SB) > Table F-2, Column RCS Barrier Loss Table F-2 Containment Radiation Time After S/D FC Barrier Loss:

RM-1CR-3589SA or RM-1CR-3590SB RCS Barrier Loss:

RM-1CR-3561A-SA, RM-1CR-3561B-SB, RM-1CR-3561C-SA, or RM-1CR-3561D-SB CNMT Potential Loss:

RM-1CR-3589SA or RM-1CR-3590SB 0 - 1 hr 130 R/hr 1.37E+03 mR/hr 2360 R/hr 1 - 2 hrs 110 R/hr 1.12E+03 mR/hr 2000 R/hr 2 - 8 hrs 70 R/hr 6.35E+02 mR/hr 1300 R/hr

> 8 hrs 21 R/hr 1.37E+02 mR/hr 390 R/hr Definition(s):

None Basis:

A Containment Ventilation Isolation radiation monitor reading greater than Table F-2, RCS Barrier Loss (ref. 1) indicates the release of reactor coolant into containment. The readings assume the instantaneous release and dispersal of the reactor coolant noble gas and iodine inventory associated with normal operating concentrations (i.e., within Technical Specifications) into the Containment atmosphere. Because of the very high fuel clad integrity, only small amounts of noble gases would be dissolved in the primary coolant.

The radiation monitor reading corresponds to an instantaneous release of all reactor coolant mass into the containment, assuming that reactor coolant activity equals Technical Specification allowable limits. This value is lower than that specified for Fuel Clad Barrier Loss threshold C.1 since it indicates a loss of the RCS Barrier only.

There is no Potential Loss threshold associated with RCS Activity / Containment Radiation.

HNP Basis Reference(s):

1. EP-EALCALC-HNP-1701, Containment Radiation EAL Threshold Values

2. DBD-304, Radiation Monitoring System and Gross Failed Fuel Monitor

3. NEI 99-01 CNMT Radiation / RCS Activity RCS Loss 3.A

ATTACHMENT 2 Fission Product Barrier Loss/Potential Loss Matrix and Bases EP-EAL Rev. XXX DRAFT Page 208 of 220 Barrier:

Containment Category:

C. CNMT Radiation/RCS Activity Degradation Threat: Potential Loss Threshold:

1. RM-1CR-3589SA or RM-1CR-3590SB > Table F-2, Column CNMT Potential Loss Table F-2 Containment Radiation Time After S/D FC Barrier Loss:

RM-1CR-3589SA or RM-1CR-3590SB RCS Barrier Loss:

RM-1CR-3561A-SA, RM-1CR-3561B-SB, RM-1CR-3561C-SA, or RM-1CR-3561D-SB CNMT Potential Loss:

RM-1CR-3589SA or RM-1CR-3590SB 0 - 1 hr 130 R/hr 1.37E+03 mR/hr 2360 R/hr 1 - 2 hrs 110 R/hr 1.12E+03 mR/hr 2000 R/hr 2 - 8 hrs 70 R/hr 6.35E+02 mR/hr 1300 R/hr

> 8 hrs 21 R/hr 1.37E+02 mR/hr 390 R/hr Definition(s):

None Basis:

Containment radiation monitor readings on RM-1CR-3589SA or RM-1CR-3590SB >

Table F-2 column CNMT Potential Loss indicate significant fuel damage well in excess of that required for loss of the RCS barrier and the Fuel Clad barrier (ref. 1).

The readings are higher than that specified for Fuel Clad Loss C.1 and RCS Loss C.1.

Containment radiation readings at or above the Containment barrier Potential Loss threshold, therefore, signify a loss of two fission product barriers and Potential Loss of the third, indicating the need to upgrade the emergency classification to a General Emergency.

RM-1CR-3589SA and RM-1CR-3590SB are the Containment High Range Monitors that provide indication of radiation levels in Containment during and after postulated accidents (ref. 2).

The radiation monitor reading corresponds to an instantaneous release of all reactor coolant mass into the containment, assuming that 20% of the fuel cladding has failed. This level of fuel clad failure is well above that used to determine the analogous Fuel Clad Barrier Loss and RCS Barrier Loss thresholds.

ATTACHMENT 2 Fission Product Barrier Loss/Potential Loss Matrix and Bases EP-EAL Rev. XXX DRAFT Page 209 of 220 NUREG-1228, Source Estimations During Incident Response to Severe Nuclear Power Plant Accidents, indicates the fuel clad failure must be greater than approximately 20% in order for there to be a major release of radioactivity requiring offsite protective actions. For this condition to exist, there must already have been a loss of the RCS Barrier and the Fuel Clad Barrier. It is therefore prudent to treat this condition as a potential loss of containment which would then escalate the ECL to a General Emergency.

HNP Basis Reference(s):

1. EP-EALCALC-HNP-1701, Containment Radiation EAL Threshold Values

2. DBD-304, Radiation Monitoring System and Gross Failed Fuel Monitor

3. NEI 99-01 CNMT Radiation / RCS Activity Containment Potential Loss 3.A

U.S. Nuclear Regulatory Commission Serial RA-18-0248, Enclosure 3 SERIAL RA-18-0248 ENCLOSURE 3 PROPOSED HARRIS NUCLEAR PLANT EMERGENCY ACTION LEVEL TECHNICAL BASES DOCUMENT CHANGES, EP-EAL (MARKUP)

SHEARON HARRIS NUCLEAR POWER PLANT, UNIT 1 DOCKET NO. 50-400 RENEWED LICENSE NUMBER NPF-63

ATTACHMENT 1 EAL Bases EP-EAL Rev. 17 Page 70 of 219 Category:

C - Cold Shutdown / Refueling System Malfunction Subcategory:

1 - RCS Level Initiating Condition: Loss of RCS inventory affecting core decay heat removal capability EAL:

CS1.3 Site Area Emergency RCS water level cannot be monitored for 30 min. Note 1

AND Core uncovery is indicated by any of the following:

x UNPLANNED increase in any Table C-1 sump or tank of sufficient magnitude to indicate core uncovery x

Containment radiation > 10,000 R/hr (RM-1CR-3589-SA or RM-1CR-3590-SB) x Erratic source range monitor indication Note 1:

The Emergency Coordinator should declare the event promptly upon determining that time limit has been exceeded, or will likely be exceeded.

Table C-1 Sumps / Tanks x

Containment sumps x

PRT x

RCDT x

CCW surge tank x

RAB sumps x

RWST x

RMWST x

Recycle Holdup Tank Mode Applicability:

5 - Cold Shutdown, 6 - Refueling Definition(s):

UNISOLABLE - An open or breached system line that cannot be isolated, remotely or locally.

UNPLANNED - A parameter change or an event that is not 1) the result of an intended evolution or 2) an expected plant response to a transient. The cause of the parameter change or event may be known or unknown.

Basis:

In this EAL, all RCS water level indication would be unavailable for greater than 30 minutes, and the RCS inventory loss must be detected by indirect leakage indications. Sump level increases must be evaluated against other potential sources of leakage. If the make-up rate to the RCS unexplainably rises above the pre-established rate, a loss of RCS inventory may be occurring even if the source of the leakage cannot be immediately identified. Sumps and tanks where RCS leakage may accumulate are listed in listed in Table C-1(ref. 1, 2).

Replace with:

"A Containment Ventilation Isolation Radiation Monitor >

2.6E+04 mR/hr (RM-1CR-3561A-SA, RM-1CR-3561B-SB, RM-1CR-3561C-SA, or RM-1CR-3561D-SB)"

ATTACHMENT 1 EAL Bases EP-EAL Rev. 17 Page 71 of 219 In the Refueling Mode, as water level in the reactor vessel lowers, the dose rate above the core will increase. The dose rate due to this core shine should result in indications on installed area radiation monitors (RM-1CR-3589-SA or RM-1CR-3590-SB). If these radiation monitors reach and exceed 10,000 R/hr, a loss of inventory with potential to uncover the core is likely to have occurred (ref. 4).

Post-TMI accident studies indicated that the installed PWR nuclear instrumentation will operate erratically when the core is uncovered and that this should be used as a tool for making such determinations.

This IC addresses a significant and prolonged loss of RCS inventory control and makeup capability leading to IMMINENT fuel damage. The lost inventory may be due to a RCS component failure, a loss of configuration control or prolonged boiling of reactor coolant.

These conditions entail major failures of plant functions needed for protection of the public and thus warrant a Site Area Emergency declaration.

Following an extended loss of core decay heat removal and inventory makeup, decay heat will cause reactor coolant boiling and a further reduction in reactor vessel level. If RCS level cannot be restored, fuel damage is probable.

The 30-minute criterion is tied to a readily recognizable event start time (i.e., the total loss of ability to monitor level), and allows sufficient time to monitor, assess and correlate reactor and plant conditions to determine if core uncovery has actually occurred (i.e., to account for various accident progression and instrumentation uncertainties). It also allows sufficient time for performance of actions to terminate leakage, recover inventory control/makeup equipment and/or restore level monitoring.

The inability to monitor RCS level may be caused by instrumentation and/or power failures, or water level dropping below the range of available instrumentation. If water level cannot be monitored, operators may determine that an inventory loss is occurring by observing changes in sump and/or tank levels. Sump and/or tank level changes must be evaluated against other potential sources of water flow to ensure they are indicative of leakage from the RCS.

This EAL addresses concerns raised by Generic Letter 88-17, Loss of Decay Heat Removal; SECY 91-283, Evaluation of Shutdown and Low Power Risk Issues; NUREG-1449, Shutdown and Low-Power Operation at Commercial Nuclear Power Plants in the United States; and NUMARC 91-06, Guidelines for Industry Actions to Assess Shutdown Management.

Escalation of the emergency classification level would be via IC CG1 or RG1 HNP Basis Reference(s):

1. GP-001, Reactor Coolant System Fill and Vent Mode 5

2. GP-008, Draining the Reactor Coolant System

3. GP-009, Refueling Cavity Fill, Refueling and Drain of the Refueling Cavity Modes 5-6-5

4. AOP-031-BD, Loss of Refueling Cavity Integrity-Basis Document

5. NEI 99-01 CS1 Add INSERT B Replace with INSERT A Replace with: "CSD-EP-HNP-0101-06, Radiation Monitor Readings for Core Uncovery during Refueling"

INSERT A:

INSERT B:

EAL values should be determined with a margin sufficient to ensure that an accurate monitor reading is available. For example, an EAL monitor reading might be set at 90% to 95% of the highest accurate monitor reading.

A single calculated radiation monitor reading does not represent core uncovery for all event scenarios due to multiple variables that can affect the source term (i.e., number of fuel assemblies in the core, fuel burn up in each assembly, and time after shutdown). Therefore, consideration has been given so that the threshold value of >

2.6E+04 mR/hr on the CVI radiation monitors will be low enough to be a valid indication of fuel uncovery, but high enough so that inadvertent classifications are not caused by maintenance events or other conditions that may increase radiation levels without a coincident loss of reactor vessel water level (ref. 4).

HNP utilizes CVI area radiation monitors RM-1CR-3561A-SA, RM-1CR-3561B-SB, RM-1CR-3561C-SA, and RM-1CR-3561D-SB for evaluating conditions in containment.

The sensitivity and location of these monitors allows them to detect significant changes in the loss of water shielding from the reactor cavity, which can be used to detect core uncovery.

The dose rate due to this loss of water shielding from the reactor cavity will result in indications on the Containment Ventilation Isolation (CVI) area radiation monitors. A calculation (ref. 4) shows that if these radiation monitors reach and exceed 2.6E+04 mR/hr when the reactor vessel head is removed, with RCS water level indication unavailable for greater than 30 minutes, then a loss of inventory with potential to uncover the core is likely to have occurred.

ATTACHMENT 1 EAL Bases EP-EAL Rev. 17 Page 75 of 219 Category:

C - Cold Shutdown / Refueling System Malfunction Subcategory:

1 - RCS Level Initiating Condition: Loss of RCS inventory affecting fuel clad integrity with containment challenged EAL:

CG1.2 General Emergency RCS level cannot be monitored for 30 min. (Note 1)

AND Core uncovery is indicated by any of the following:

x UNPLANNED increase in any Table C-1 sump or tank of sufficient magnitude to indicate core uncovery x

Containment radiation > 10,000 R/hr (RM-1CR-3589-SA or RM-1CR-3590-SB) x Erratic source range monitor indication AND Any Containment Challenge indication, Table C-2 Note 1:

The Emergency Coordinator should declare the event promptly upon determining that time limit has been exceeded, or will likely be exceeded.

Note 6:

If CONTAINMENT CLOSURE is re-established prior to exceeding the 30-minute time limit, declaration of a General Emergency is not required.

Table C-1 Sumps / Tanks x

Containment sumps x

PRT x

RCDT x

CCW surge tank x

RAB sumps x

RWST x

RMWST x

Recycle Holdup Tank Table C-2 Containment Challenge Indications x

CONTAINMENT CLOSURE not established (Note 6) x Containment hydrogen concentration 4

x UNPLANNED rise in Containment pressure Replace with:

"A Containment Ventilation Isolation Radiation Monitor >

2.6E+04 mR/hr (RM-1CR-3561A-SA, RM-1CR-3561B-SB, RM-1CR-3561C-SA, or RM-1CR-3561D-SB)"

ATTACHMENT 1 EAL Bases EP-EAL Rev. 17 Page 76 of 219 Mode Applicability:

5 - Cold Shutdown, 6 - Refueling Definition(s):

CONTAINMENT CLOSURE - The procedurally defined actions taken to secure containment and its associated structures, systems, and components as a functional barrier to fission product release under shutdown conditions. As applied to HNP, Containment Closure is established when containment penetration closure is established in accordance with Technical Specifications 3/4.9.4.

UNISOLABLE - An open or breached system line that cannot be isolated, remotely or locally.

UNPLANNED - A parameter change or an event that is not 1) the result of an intended evolution or 2) an expected plant response to a transient. The cause of the parameter change or event may be known or unknown.

Basis:

In this EAL, all RCS water level indication would be unavailable for greater than 30 minutes, and the RCS inventory loss must be detected by indirect leakage indications. Sump level increases must be evaluated against other potential sources of leakage. If the make-up rate to the RCS unexplainably rises above the pre-established rate, a loss of RCS inventory may be occurring even if the source of the leakage cannot be immediately identified. Sumps and tanks where RCS leakage may accumulate are listed in listed in Table C-1 (ref. 1, 2).

In the Refueling Mode, as water level in the reactor vessel lowers, the dose rate above the core will increase. The dose rate due to this core shine should result in indications on installed area radiation monitors (RM-1CR-3589-SA or RM-1CR-3590-SB). If these radiation monitors reach and exceed 10,000 R/hr, a loss of inventory with potential to uncover the core is likely to have occurred (ref. 4).

Post-TMI accident studies indicated that the installed PWR nuclear instrumentation will operate erratically when the core is uncovered and that this should be used as a tool for making such determinations.

Three conditions are associated with a challenge to containment integrity:

x CONTAINMENT CLOSURE is not established.

x In the early stages of a core uncovery event, it is unlikely that hydrogen buildup due to a core uncovery could result in an explosive mixture of dissolved gases in the containment. However, containment monitoring and/or sampling should be performed to verify this assumption and a General Emergency declared if it is determined that an explosive mixture exists. An explosive mixture can be formed when hydrogen gas concentration in the containment atmosphere is greater than 4% by volume in the presence of oxygen.

x Any unplanned increase in containment pressure in the Cold Shutdown or Refueling mode indicates a potential loss of containment closure capability. Unplanned containment pressure increases indicates containment closure cannot be assured and the containment cannot be relied upon as a barrier to fission product release.

Add INSERT C

INSERT C:

The dose rate due to core uncover will result in indications on the Containment Ventilation Isolation (CVI) area radiation monitors. A calculation (ref. 4) shows that if these radiation monitors reach and exceed 2.6E+04 mR/hr when the reactor vessel head is removed, with RCS water level indication unavailable for greater than 30 minutes, then a loss of inventory with potential to uncover the core is likely to have occurred.

ATTACHMENT 1 EAL Bases EP-EAL Rev. 17 Page 77 of 219 This IC addresses the inability to restore and maintain reactor vessel level above the top of active fuel with containment challenged. This condition represents actual or IMMINENT substantial core degradation or melting with potential for loss of containment integrity.